bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract P4-08-07: CDCP1 cleavage is necessary for homodimerization-induced migration of triple-negative breast cancer
Authors: Wright H , Motazedi M , Nelson L , Aulmoli J , Flanagan L , Razorenova O
Published: May 2016

Triple negative breast cancer (TNBC) is a highly aggressive and metastatic form of breast cancer that lacks the estrogen, progesterone, and HER2 receptors and is resistant to targeted and hormone therapies. TNBCs express high levels of the transmembrane glycoprotein, CUB-domain containing protein 1 (CDCP1), which has been correlated with the aggressiveness and poor prognosis of multiple carcinomas. Full-length CDCP1 (flCDCP1) can be proteolytically cleaved, resulting in a cleaved membrane-bound isoform (cCDCP1). CDCP1 is phosphorylated by Src family kinases in its full-length and cleaved states, which is important for its pro-metastatic signaling. We observed that cCDCP1, compared to flCDCP1, induced a dramatic increase in phosphorylation of the migration-associated proteins: PKCδ, ERK1/2, and p38 MAPK in HEK 293T. In addition, only cCDCP1 induced migration of HEK 293T cells and rescued migration of the TNBC cell line, MDA-MB-231, expressing shRNA against CDCP1. Importantly, we found that only cCDCP1 is capable of dimerization, which can be blocked by expression of the extracellular portion of cCDCP1 (ECC), indicating that dimerization occurs through CDCP1's ectodomain. Furthermore, we found that ECC inhibited phosphorylation of PKCδ by Src and migration of TNBC cells, indicating that the cCDCP1 dimer is an important contributor to TNBC aggressiveness. These studies have important implications for development of a therapeutic to block CDCP1 activity and TNBC metastasis.

Citation Format: Wright H, Motazedi M, Nelson L, Aulmoli J, Flanagan L, Razorenova O. CDCP1 cleavage is necessary for homodimerization-induced migration of triple-negative breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-08-07.
Abstract P4-09-01: FGFR1 protein expression is associated with prognosis in primary breast cancer: A comprehensive analysis of gene copy number, mRNA and protein expression
Authors: Tomiguchi M , Yamamoto Y , Yamamoto-Ibusuki M , Yamaguchi R , Fujiki Y , Fujiwara S , Sueta A , Takeshita T , Inao T , Iwase H
Published: May 2016

Background: The Cancer Genome Atlas (TCGA) showed that copy number gain/amplification of FGFR1 was around 10% in primary breast cancer. FGFR1 gene amplification in breast cancer has been reported in some studies, more likely seen in ER-positive subtype. Several preclinical and clinical studies demonstrated that FGFR1 was one of novel targets of therapy for metastatic breast cancer. Previous studies suggested that aberrant FGFR1 expression was associated with poor prognosis, while there was no report that compared copy number aberration, mRNA and protein expression. The aim of this study is to analyze FGFR1 gene copy number, expression levels of FGFR1 mRNA and FGFR1 protein in ER-positive/HER2-negative primary breast cancer, and to examine the relationship between FGFR1 status and clinicopathological parameters including prognosis.

Methods: The cohort of this study included 307 ER-positive/HER2-negative primary invasive breast cancer patients treated with standard care at Kumamoto University Hospital between June 2000 and January 2011. We performed a comprehensive analysis of FGFR1 at the levels of gene copy number, mRNA and FGFR1 protein expression analyzed by qPCR, qRT-PCR and immunohistochemistry, respectively.

Results: FGFR1 gain/amplification was identified in 43 (14.0%) out of 307 patients. FGFR1 gain/amplification had significantly associated with higher nuclear grade (p=0.010). No correlations between FGFR1 mRNA expression levels and any clinicopathological factors were found. Expression levels of FGFR1 protein was positively associated with invasive tumor size (p=0.039). Modest positive correlations between these three (FGFR1 gene gain/amplification, expression levels of FGFR1 mRNA and FGFR1 protein) were found. The univariate analysis revealed that high FGFR1 protein expression was significantly related to poor prognosis (p=0.0019, HR: 2.63, 95%CI: 1.17-5.98) in terms of relapse-free survival (RFS) but not breast cancer-specific survival. The univariate analysis did not show that any factors except FGFR1 protein expression were significantly associated with RFS in this cohort.

Conclusion: Expression levels of FGFR1 protein may be an independent prognostic factor in terms of RFS for ER-positive/HER2-negative breast cancer patients receiving standard care.

Citation Format: Tomiguchi M, Yamamoto Y, Yamamoto-Ibusuki M, Yamaguchi R, Fujiki Y, Fujiwara S, Sueta A, Takeshita T, Inao T, Iwase H. FGFR1 protein expression is associated with prognosis in primary breast cancer: A comprehensive analysis of gene copy number, mRNA and protein expression. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-09-01.
Abstract P4-14-16: T-cell clonality increases after neoadjuvant treatment with trastuzumab and pertuzumab
Authors: Howie LJ , Marcom PK , Topping DL , Force J , Emerson R , Bhavsar NA , Abbott SE , Parks M , Robins HS , Blackwell KL
Published: May 2016

Background: Baseline TIL density and T-cell clonality predict pathological complete response (pCR) to neoadjuvant (NA) trastuzumab (TRAS). Preclinical data suggests that a major mechanism of TRAS is enhancement of antibody-dependent cytoxicity (ADCC) and T-cell mediated tumor kill and that the combination of TRAS with pertuzumab (PERT) may enhance ADCC. This study quantifies both TIL density and T-cell clonality in both pre and post-NA samples from patients receiving NA TRAS +/- PERT.

Methods: Sequential subjects treated with NA docetaxel, carboplatin and TRAS +/- PERT were identified and pre-treatment (n=39) and post-treatment specimens (n=44, 36 pairs of pre and post-treatment; 19 with pCR) were sequenced using the ImmunoSEQ platform (Adaptive Bioscience, Seattle, WA). T-cell density and dominant T-cell clonality were measured by TCR sequencing and then associated with pCR using a two-tailed Mann-Whitney U test comparing patients with pCR versus those without. Paired values were compared using the sign test to evaluate change in pre and post-treatment T-cell density and clonality. TIL density was performed using standard IHC methodology.

Results: There was a trend towards increased T-cell clonality after treatment (p=0.08). T-cell clonality post-treatment was significantly increased compared to pre-treatment in those samples where post-treatment tumor was available (p=0.01). There was no difference in T-cell clonality between pre- and post-treatment in normal tissue from pts achieving a pCR (p=1.00). There was no difference in post-treatment T cell clonality when treated with TRAS vs. TRAS + PERT (p=0.19). No differences in the % of pretreatment TILs or T-cell clonality were seen in those who obtained a pCR vs. those who did not (p=0.39 and p=0.85). In addition, no differences in T-cell clonality were seen based on ER status in either pre-treatment or post-treatment samples (p=0.40/0.48)

Conclusions: After treatment with TRAS +/- PERT, there was an increase in T-cell clonality suggesting an enhanced immune response as a mechanism of action for HER2 targeting antibodies. This analysis is currently limited by a small sample size and high rate of pCR. We plan to include additional paired samples which may help to better demonstrate the increased immune response that occurs with HER-2 targeting antibodies.

Citation Format: Howie LJ, Marcom PK, Topping DL, Force J, Emerson R, Bhavsar NA, Abbott SE, Parks M, Robins HS, Blackwell KL. T-cell clonality increases after neoadjuvant treatment with trastuzumab and pertuzumab. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-14-16.
Abstract P5-01-01: Real-time imaging of lymph node metastasis in response to systemic ezrin inhibitor treatment in breast cancer
Authors: Ghaffari A , Hoskin V , Mullins G , Greer P , Kiefer F , Madarnas Y , SenGupta S , Elliott B
Published: May 2016

Lymph node (LN) metastasis is a key driver of recurrence and survival in breast cancer (BC) patients. However, the mechanisms of metastatic dissemination of tumour cells from LNs to distant sites and their predictors of response to systemic therapy remain poorly understood, mainly due to a lack of non-invasive in vivo imaging models. We have recently described ezrin, a pro-metastatic crosslinker protein, as a regulator of tumour lymphangiogenesis and metastasis in BC (Breast Cancer Res. 2014; 16(5): 438). Furthermore, we demonstrated significant association of high ezrin expression with lymphovascular invasion in a cohort (n=63) of premenopausal patients with invasive BC (p =0.024). These findings prompted us to examine the role of ezrin in migration and invasion of metastatic tumour cells in LNs and their response to ezrin-targeted therapy. Using a locally accrued LN positive patient cohort (n=94), we demonstrated a significant association between high ezrin levels and reduced recurrence-free survival (univariate Log-rank test, p=0.033), suggesting that ezrin is a potential predictor of relapse in LN positive BC. To address the mechanistic role of ezrin in LN metastasis, we developed a novel intravital imaging model using a lymphatic reporter transgenic mouse (B6-prox1-mOrange2-pA-BAC) to examine the response of tumour-draining LN to anti-ezrin systemic therapy in real time. Next, we tested the effects of a small molecule ezrin inhibitor (NSC668394) in vitro and observed significant suppression of ezrin activation (p-T567) and cancer cell invasive phenotype. Intravital imaging of inguinal LN metastases, derived from subcutaneously implanted breast adenocarcinoma E0771-LMV (lung metastatic variant) cells, demonstrated significant reduction in mobility and invasiveness (Mann Whitney, p<0.0001) of metastatic cells following systemic treatment with NSC668394 (0.5 mg/kg at 24h and 8h prior to imaging). Interestingly, LN metastases engagement by host T cell (CD3+) was notably increased, whereas T cell mobility was not affected by ezrin inhibition. Our findings present a novel non-invasive imaging model to study the LN metastasis response to anti-cancer therapy in real time, and provide new insight into the role of ezrin as a potential anti-metastatic target in BC.

(Supported by CRS, CIHR, CBCF, BCAK, Queen's SRC).

Citation Format: Ghaffari A, Hoskin V, Mullins G, Greer P, Kiefer F, Madarnas Y, SenGupta S, Elliott B. Real-time imaging of lymph node metastasis in response to systemic ezrin inhibitor treatment in breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-01-01.
Abstract P5-03-14: MLN0128 regulates survival signaling by AKT and its downstream effectors in HER2+ breast cancer model
Authors: De PK , Carlson JH , Sun Y , Lin X , Williams C , Dey N , Leyland-Jones BR
Published: May 2016

Evading apoptosis is considered to be a hallmark of cancers including breast cancer, since mutations in apoptotic regulators invariably accompany tumorigenesis. Chemotherapeutic agents induce apoptosis, and hence disruption of apoptosis during tumor progression may promote drug resistance. AKT is an apoptotic regulator that is activated in HER2+ breast tumor cells and promotes anti-HER2 therapy resistance in vitro. Nevertheless, how mTORC1/C2-AKT signaling disables apoptosis and its contribution to clinical drug resistance are not clear yet. Using HER2 amplified breast cancer cells [BT474 (HER2+/Trastuzumab-sensitive), BT474HerR (HER2+/Trastuzumab-resistant), HCC1954 and MDA-MB453 (both are HER2+/PIK3CA kinase domain mutated)], we show that mTORC1/C2 inhibitor; MLN0128 abrogates AKT (Ser473), Survivin and controls its downstream effectors of apoptotic signaling molecules (e.g. cleaved Caspase 3/9, cleaved PARP, MCL and BIM). MLN0128 also induces annexinV positive cells and regulates cellular proliferation (ON-TOP 3D colony formation and real-time proliferation assay). Additionally, increased cleaved Caspase 3 and decreased MCL1 expression were also observed following MLN0128 treatment in HER2+ xenograft model along with tumor growth inhibition. Our studies provide strong experimental evidence that high apoptotic signaling –specifically reduced MCL1 and increased cleaved-CASPASE3 expression expedite the response of targeted therapy that directly inhibits mTORC1/C2-AKT signaling.

Citation Format: De PK, Carlson JH, Sun Y, Lin X, Williams C, Dey N, Leyland-Jones BR. MLN0128 regulates survival signaling by AKT and its downstream effectors in HER2+ breast cancer model. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-03-14.
Abstract P5-04-19: JAK2 copy number and targeted JAK2 inhibition of TNBC cell lines
Authors: Chen M , Andreozzi M , Gonzalez-Malerva L , Eaton S , Pockaj B , Barrett MT , Anderson KS
Published: May 2016

Background A subset of triple negative breast cancers (TNBC) has somatic amplification of chromosome 9p24.1, encoding PD-L1, PD-L2, and JAK2 (the "PDJ" amplicon). The JAK/STAT pathway promotes malignant transformation and proliferation, and the JAK1/JAK2 inhibitor ruxolitinib is being evaluated in early phase clinical trials in breast cancer. This study was designed to measure the frequency of PDJ copy number gain in existing TNBC cell lines, and determine the impact of targeted JAK2 inhibition on cellular proliferation.

Methods: Copy number alterations were measured in nine TNBC cell lines (MDA-MB-453, MDA-MB-436, BT549, MDA-MB231, MFM-223, MDA-MB-468, H5578T, MDA-MB-157, HCC1937) by array comparative genomic hybridization (aCGH). JAK2 and pSTAT3 expression was measured by immunoblot in four of the TNBC lines (HCC1937, MDA-MB-468, MDA-MB-231, MDA-MB-436) and compared with MCF10A, SK-BR3, and T47D. To selectively inhibit JAK2, lentiviral vectors encoding five different shRNA targeting JAK2 were generated. Ruxolitinib treatment was performed at 25 uM for 48 hrs and 72 hrs. Cell proliferation was measured by CellTiter-Glo.

Results: All TNBC cell lines had an elevated level of baseline protein expression of JAK2 and pSTAT3 compared to SK-BR3, T47D, and MCF10A. Of the nine TNBC cell lines, only MDA-MB-436 and BT549 had copy number gain of 9p24.1 (log2ratio<1). Four independent shRNA efficiently silenced over 90% of JAK2 expression in MDA-MB-231. The inhibition of JAK2 in MDA-MB-231 was associated with a decrease in both JAK2 and pSTAT3 protein expression and reduction in cell proliferation compared to control shRNA after 96 hrs (p<0.0001). Inhibition of proliferation was also observed for both MDA-MB-231 and MDA-MB-436 after ruxolitinib treatment.

Conclusion These results demonstrate that existing TNBC cell lines have varying copy number alterations of chromosome 9p24.1 encoding JAK2, and targeted JAK2 inhibition in TNBC inhibits cell proliferation.

Citation Format: Chen M, Andreozzi M, Gonzalez-Malerva L, Eaton S, Pockaj B, Barrett MT, Anderson KS. JAK2 copy number and targeted JAK2 inhibition of TNBC cell lines. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-04-19.
Abstract P5-05-03: Targeting hypoxia-induced cancer cell metabolism in breast cancer
Authors: Cavazos DA , Gruslova A , Garcia M , Brenner AJ
Published: May 2016

Rational: Hypoxia contributes to high tumor grade in human breast cancer and is associated with resistance to radiation and chemotherapy. Hypoxia is generally encountered in perinecrotic regions throughout the heterogeneous tumor microenvironment and may be due to rapid tumor grow, insufficient neovascularization or as a result of antiangiogenic and chemoradiation therapies which cause acute vascular thrombosis. Cancer stem-like cells residing within these hypoxic zones compensate for the low concentration of oxygen through alterations in metabolism that favor aerobic glycolysis and de novo fatty acid synthesis. These metabolic derangements are known to enhance proliferation and survival, although the contributing molecular mechanisms are not fully understood. Here we evaluate a panel of FDA approved azole drugs for alternative use as glycolytic inhibitors with and without the fatty acid synthase (FASN) inhibitor, TBV-3166. TVB-3166 is currently in phase II clinical trials and is the first FASNi approved for human testing. METHODS: IC50 values of single or combined agents were determined by MTT under conditions of normoxia and hypoxia using sister plates of estrogen receptor positive or triple negative breast cancer cells, MCF-7, SKBR3 and MDA-MB-231. RESULTS: Because the combination of Itraconazole and TVB-3166 displayed a synergistic enhancement in cell death at a low nanomolar concentrations in MCF-7 cells, we next assessed the efficacy of these drugs in an in vivo xenograft model of breast cancer. Here, 3.6 million MCF-7 cells were implanted into the right flanks of (n=16) athymic nude mice, which were then randomized by tumor volume into 4 groups. Itraconazole and TVB-3166 were administered at 60 mg/kg daily by oral gavage as single agents or combined throughout the duration of the study. After three weeks, mice treated with combined inhibitors exhibited best response with a statistically significant decrease in tumor volume compared to the vehicle control group. CONCLUSION: Given the significant tumor response to the combination of metabolic inhibitors, further studies that evaluate the radiosensitizing effects under conditions of hypoxia are warranted. By targeting hypoxia-induced metabolic pathways during radiotherapy, we may enhance cancer stem-like cell death to dramatically improve patient outcome.

Citation Format: Cavazos DA, Gruslova A, Garcia M, Brenner AJ. Targeting hypoxia-induced cancer cell metabolism in breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-05-03.
Abstract P5-07-08: The clinical utility of alternative chromosome 17 probes in equivocal HER2 results
Authors: Sneige N , Gong Y , Multani AS , Ibrahim NK
Published: May 2016

Background

Acurrate assessment of HER2 status in patients with breast cancer is critical in selecting patients for targeted therapy. In 2013, the American Society of Clinical Oncology-/College of American Pathologists (ASCO/CAP) released new guidelines for HER2 testing in an attempt to more acurately identify all breast cancer patients who are eligible for HER2 targeted therapy; these guidelines included new cutoff points for HER2/CEP17 ratio by in situ hybridization (ISH) or average HER2 copy number/cell and recommended the use of a reflex test with alternative ISH chromosome 17 probe for resolving cases with equivocal HER2 ISH results. We sought to determine the clinical utility of alternative chromosome 17 probes in such equivocal cases.

Patients and Methods

Our institution's database of HER2 dual- probe ISH results was searched for cases of invasive breast cancer with a HER2/CEP17 ratio of <2 and an average HER2 copy number of >4 and <6 signals/cell (i.e., cases meeting the new ASCO/CAP definition of equivocal). Of these, 30 consecutive cases with available corresponding sections were selected for additional chromosome 17 studies using probes for Smith-Magenis syndrome (SMS) and retinoic acid receptor alpha (RARA) genes. A eusomic copy number exhibited in one or both of these loci was used to calculate a revised HER2/chromosome-17 ratio by using the eusomic gene locus as the reference.

Results

Of 5489 cases of invasive breast cancer tested by dual-probe ISH for HER2 gene status, 316 (5.7%) cases were found to have equivocal results according to the 2013 ASCO/CAP guidelines. Further analysis of the 30 equivocal consecutive cases using the alternative chromosome 17 probes (SMS/RARA), 17 cases were upgraded from equivocal to positive HER2 status, and 13 cases remained unchanged.

Conclusion

The use of alternative chromosome 17 probes effectively determines true HER2 status in most equivocal HER2 ISH cases. Equivocal results are common; therefore, we advocate testing for alternative chromosome 17 genes to better categorize equivocal cases under the new ASCO/CAP guidelines. Additional analysis of the remaining equivocal cases and their relation to disease progression is underway and will be presented at the meeting.

Citation Format: Sneige N, Gong Y, Multani AS, Ibrahim NK. The clinical utility of alternative chromosome 17 probes in equivocal HER2 results. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-07-08.
Abstract P5-13-06: Concurrent gonadotropin-releasing hormone (GnRH) agonist administration with chemotherapy improves neoadjuvant chemotherapy responses in young premenopausal breast cancer patients
Authors: Yoon TI , Kim HJ , Yu JH , Sohn G , Ko BS , Lee JW , Son BH , Ahn SH
Published: May 2016

Background

Gonadotropin-releasing hormone (GnRH) agonist therapy for ovarian function preservation shows promising results. This study aimed to determine the oncologic efficacy of GnRH agonist treatment concurrent with chemotherapy in a neoadjuvant setting.

Patients and Methods

A retrospective analysis was performed on 332 cases of invasive breast cancer in patients who were <40 years old at diagnosis and received GnRH agonists concurrent with neoadjuvant chemotherapy (GnRH agonist group) or neoadjuvant chemotherapy alone (neochemotherapy-alone group) at Asan Medical Center from December 2010 to September 2014. Pathologic complete response rates (pCR) and Ki-67 changes were evaluated between the two groups. For hormone receptor (HR)-positive tumors, the clinical response and preoperative endocrine prognostic index (PEPI) score also were evaluated.

Results

The median age was 32 ± 3.9 and 36 ± 3.0 years old in the GnRH agonist group and neochemotherapy-alone group, respectively (P < .001). Adjusted for tumor size, grade, lymph node metastasis, HR status, and chemotherapy regimen, the GnRH agonist group exhibited a higher pCR rate with an odds ratio (OR) of 2.98 (95% CI, 1.37–6.34) and more decreased Ki-67 expression during treatment (P = 0.05) than the neochemotherapy-alone group. In HR-negative tumors, the GnRH agonist group showed a higher pCR rate (multivariate OR = 3.50; 95% CI, 1.37–8.95) and more decreased Ki-67 expression (P = 0.047). In HR-positive breast cancer, the pCR rate, change in Ki-67 index, and clinical response were higher and preoperative prognostic index (PEPI) scores were lower in the GnRH agonist group, but not significant between the two treatment groups.

Conclusion

Concurrent administration of GnRH agonists during neoadjuvant chemotherapy improved pCR rates and suppressed Ki-67 expression especially in HR-negative tumors.

Citation Format: Yoon TI, Kim HJ, Yu JH, Sohn G, Ko BS, Lee JW, Son BH, Ahn SH. Concurrent gonadotropin-releasing hormone (GnRH) agonist administration with chemotherapy improves neoadjuvant chemotherapy responses in young premenopausal breast cancer patients. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-13-06.
Abstract P6-03-15: Inhibition of breast cancer tumor cell lines by simvastatin is dependent on specific p53 mutation
Authors: Ferdosi SR , Grewal H , Gonzalez-Malerva L , Eaton S , Briones N , LaBaer J , Anderson KS
Published: May 2016

Background: Simvastatin is an HMG-CoA reductase inhibitor widely used to treat cardiovascular diseases. In retrospective studies, statin treatment has been associated with a modest decrease in overall cancer incidence, including breast cancer (10-15%). Simvastatin Inhibited the PI3K/Akt/mTOR pathway in a pilot window-of-opportunity trial in neoadjuvant breast cancer. Mutation in TP53 is correlated with elevated expression of genes regulating cholesterol biosynthesis and sensitivity to statin treatment in vitro. We hypothesized that specific mutations in TP53 would be associated with differential sensitivity to simvastatin.

Method: We generated MCF10A stably transduced cell lines over-expressing ten frequent TP53 missense point mutations. We assessed the impact of TP53 mutation on growth inhibition induced by simvastatin treatment (range of 1-30 µM for 96 hrs). In parallel, induction of apoptosis was measured by caspase3 reporter assay. Illumina 4-plexed 1x50bp RNA sequencing was performed on cells with R273H, G245S, R248Q, Y234C and wt TP53 before and after exposure to 2.5 µM simvastatin.

Results: We confirmed that mutation in TP53 was markedly associated with growth inhibition by simvastatin treatment in vitro. We now demonstrate that TP53 mutation in R273C, G245S and R273H are highly sensitive to simvastatin with IC50 values ≤ 2.1 µM. In contrast, TP53 mutations in Y234C and R248Q were approximately five-fold more resistant. The resistant mutations were similar to MCF10A overexpressing wild type TP53. Growth inhibition was correlated with induction of apoptosis, and could be rescued by addition of farnesylpyrpphosphate and geranylgeranylpyrophosphate. HMGCR upregulation was observed across all treated cell lines. RNA-seq analysis confirms down regulation of the PIK3CA, PIK3CB, and Akt in the sensitive cell lines, but paradoxical upregulation in the resistant cells. Further gene expression analysis will be presented.

Conclusion: Specific TP53 mutation status may impact sensitivity of breast cancer to simvastatin treatment.

Citation Format: Ferdosi SR, Grewal H, Gonzalez-Malerva L, Eaton S, Briones N, LaBaer J, Anderson KS. Inhibition of breast cancer tumor cell lines by simvastatin is dependent on specific p53 mutation. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-03-15.
Abstract P6-03-18: Outcome of FoundationOne testing in metastatic breast cancer therapy: A single center experience
Authors: Yuan Y , Mortimer JE
Published: May 2016

Background: Next generation sequencing (NGS) has made genomic, mutation-driven, cancer medicine feasible. However, few studies have reported the importance of NGS in identifying mutation-driven treatment or whether such therapies are effective in women with metastatic breast cancer (MBC). We reviewed the impact of NGS in women with MBC at our institution.

Methods: Among the medical oncologists who treat metastatic breast cancers at the City of Hope Comprehensive Cancer Center, we identified 21 patients with HER2 negative cancers, whose tumors were submitted for FoundationOne genomic profiling. We report the individual mutation profile, potential therapeutic options, and treatment outcome.

Result: Of the 21 patients (pts), 13 had triple negative breast cancer (TNBC) and 12 of 13 (92%) had actionable mutation(s). Mutation profiles have been heterogeneous. Loss or mutations of TP53 were the most common genomic alteration in TNBC (12 of 13). Four pts received targeted therapies (everolimus in 3, pazopanib in 1) and all experienced at least partial clinical response. An additional 3 pts were treated with directed therapy but are too early to evaluate, 4 pts were not treated because of disease progression or clinical deterioration, and 1 pt was lost to follow-up. All 8 pts with ER+ disease had actionable mutations identified and 7 (88%) received targeted therapy (pazopanib in1, everolimus in 3, palbociclib in 3). All experienced at least partial clinical response; 1 was too ill for treatment. The most common genomic alterations are: PIK3CA mutation, PTEN loss, P53 mutation, FGFR mutation, and ZNF mutation.

Conclusion: Targeted genomic sequencing through FoundationOne can identify mutations that are amenable to treatment with agents that are not generally approved for use in breast cancer. In order to test the benefit of target-directed therapy, tumor should be submitted for NGS while patients have a good performance status.

Citation Format: Yuan Y, Mortimer JE. Outcome of FoundationOne testing in metastatic breast cancer therapy: A single center experience. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-03-18.
Abstract P6-07-13: New insights on HER2 amplification from the constitutional and somatic standpoints: Results from the ICGC and SIGNAL/Phare studies
Authors: Vincent-Salomon A , Ferrari A , Pivot X , Macgrogan G , Arnould L , Treilleux I , Romieux G , Sertier A-S , Thomas E , Tonon L , Boyault S , Kielbassa J , Letexier V , Pauporte I , Birbaum D , Saintigny P , Cox D , Viari A
Published: May 2016

Background: HER2-positive (HER2+) breast cancers are defined by the amplification and/or overexpression of the human epidermal growth factor receptor (HER2/ERBB2) gene on chromosome region 17q12. Although anti-HER2 targeted therapies have greatly improved treatment of HER2+ breast cancer, the magnitude of benefit varies widely between patients. Deciphering the genomic and genetic heterogeneity of HER2+ breast cancer may provide a basis to better understand their natural history, opening new avenues of treatment.

Methods: As part of the ICGC Breast Cancer Working Group effort, we combined whole genome sequencing and transcriptomic analyses of 64 HER2+ primary invasive carcinomas, and a genome wide association study (GWAS) of over 9.836 breast cancer patients in the prospective SIGNAL/PHARE cohort (NCT00381901 – RECF1098).

Results: Using WGS data we precisely delineate the ERBB2 amplicon as a 106 kb region involving six genes and show that the amplification mechanism was consistent with breakage-fusion-bridge (BFB) cycles. Four RNA expression-based groups were identified, displaying specific genomic alterations in terms of amplification, rearrangements and mutations. On other hand, GWAS analyses failed to identify any constitutional variants associated with HER2 amplification.

Discussion: By combining whole genome sequencing and expression analysis, we provide evidence showing that HER2+ tumours display considerably more molecular heterogeneity than previously reported. These results are reinforced with the lack of association between any genetic variants and HER2 amplification from GWAS analyses. Taken as a whole, these results suggest that HER2+ breast cancers do not represent per se a homogeneous subtype, but are distributed along the whole breast cancer spectrum, from ER-positive luminal to ER-negative basal phenotype. Genome alterations present in HER2+ tumors are in accordance with these phenotypes, and it is likely that the HER2 amplification is a secondary event in the course of tumorigenesis, not favored by any particular constitutional or somatic genetic variants.

Citation Format: Vincent-Salomon A, Ferrari A, Pivot X, Macgrogan G, Arnould L, Treilleux I, Romieux G, Sertier A-S, Thomas E, Tonon L, Boyault S, Kielbassa J, Letexier V, Pauporte I, Birbaum D, Saintigny P, Cox D, Viari A. New insights on HER2 amplification from the constitutional and somatic standpoints: Results from the ICGC and SIGNAL/Phare studies. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-07-13.
Abstract P6-08-08: Expression and role of ING3 gene in breast cancer
Authors: Kalender ME , Cakir M , Ergun S , Oztuzcu S , Cengiz B , Ulasli M , Sevinc A , Camci C
Published: May 2016

Background: Inhibitor of growth (ING) tumor suppressor gene family has been discovered over the past decade and five different genes have been identified from ING1 to ING5. They have some functions like cell transcription regulation, cell cycle control, DNA repair and apoptosis. Because of the fact that ING3 gene expression has not been studied in breast cancer so far, we aimed to determine whether there was a relationship between ING3 gene expression and breast cancer prognostic factors.

Methods: 46 female breast cancer patients in different stages were enrolled to our study. ING3 gene expressions obtained from tumoral and healthy breast tissue samples of patients were evaluated together with pathological and histological parameters.

Results: The median age of the patients was 49 years. ING3 expression rate has been significantly higher in the tumor tissue compared to normal tissue and was statistically significant (p=0.001). In estrogen receptor (ER) and progesterone receptor (PR) positive patients, gene expression ratio was significantly higher than negative ones (p<0.001 and p<0.001, respectively). ING3 expression in tumor tissues of the patients with advanced disease (stage 3-4) was detected higher than ones with early stage disease and it was found to be statistically significant at the border (p=0.048). Moreover, there were no significant changes when ING3 gene expressions were compared with c-erbB2 (Receptor tyrosine-protein kinase erbB-2) status and tumor grade (p> 0.05).

Conclusions: This study was the first study on ING3 gene expression in breast cancer. ING3 gene expression has been shown to be associated with the receptor positivity and advanced stage disease. Further studies should be conducted on the prognostic significance of ING3 gene in breast cancer.

Citation Format: Kalender ME, Cakir M, Ergun S, Oztuzcu S, Cengiz B, Ulasli M, Sevinc A, Camci C. Expression and role of ING3 gene in breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-08-08.
Abstract P6-12-02: Association between a dedicated program for young breast cancer patients and discussion about fertility preservation
Authors: Srikanthan A , Amir E , Warner E
Published: May 2016

Purpose: To assess whether a dedicated program, including a nurse navigator, improves the frequency of: a) documentation of fertility discussion and b) referrals for fertility preservation (FP).

Methods: A retrospective chart review and prospective survey were undertaken of a cohort of young breast cancer patients diagnosed between 2011-2013 at two academic centres in Toronto, Ontario. The Odette Cancer Center (OCC) has a dedicated program for young breast cancer patients while Princess Margaret Cancer Centre (PM) does not. Documentation of fertility discussion prior to receipt of systemic therapy was extracted from patient records. Prospective surveys were administered to the same cohort to corroborate data collected. Descriptive statistics were used to characterize baseline patient variables. Chi-squared was used to compare categorical variables and t-tests for continuous variables between the two cancer centres. Statistical significance was defined as p<0.05.

Results: At OCC and PM respectively, 91 and 81 patient charts were reviewed while 54 and 49 women returned surveys for response rates of 59% and 60% . Chart reviews demonstrated no difference in the frequency of documentation of fertility discussion (80% versus 75% for OCC and PM, p=0.44); however, surveys demonstrated higher recall of fertility discussion rates at OCC (96% versus 83%, p=0.046). A greater proportion of women were offered FP referrals at OCC, as observed in both chart reviews (53% versus 41%, p=0.18) and surveys (70% versus 46%, p=0.02). Time to initiation of chemotherapy did not significantly differ between women who underwent FP and those who did not.

Conclusion: A dedicated program for young women with breast cancer including a nurse navigator is associated with a higher frequency of FP referrals without delaying systemic therapy.

Citation Format: Srikanthan A, Amir E, Warner E. Association between a dedicated program for young breast cancer patients and discussion about fertility preservation. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-12-02.
Abstract P6-12-07: The benefit of preoperative chemotherapy in an underinsured Hispanic population with poor use of screening mammography
Authors: Komenaka IK , Djenic B , Walters J , Hsu C-H , Nodora JN , Martinez ME , Bouton M , Mehta D
Published: May 2016

Background: Despite prospective clinical trials demonstrating the safety and effectiveness of preoperative chemotherapy for nearly 2 decades, it may still be underutilized in underserved, uninsured populations most likely to present with advanced cancers. The current study was performed to evaluate the effect of preoperative chemotherapy (PC) in a Hispanic safety net population.

Methods: A retrospective review of Hispanic breast cancer patients who presented at clinical stage 2 or higher and were treated from July 2001 to February May 2015 at a safety net hospital. Sociodemographic, clinical, and treatment variables were evaluated. Surgical outcomes were evaluated. Margin status was determined for those who underwent breast conservation.

Results: The average age of the 266 patients was 45 years. 93% of the patients were insured with Medicaid or uninsured (70%). Only 24% of patients underwent screening mammography. 133 underwent PC and 133 had primary operations. Patients who underwent PC presented with larger cancers (5cm vs 3.5cm, p < 0.001). 96% of patients in PC group were not candidates for lumpectomy at presentation. However, lumpectomy was performed more often in those who underwent PC (75% vs. 57%, p = 0.01). Re-excision for margins were necessary less often in those who underwent PC (10.3% vs 27%, p = 0.01). Patients who underwent PC were also less likely to require an ALND (33% vs 47%, p = 0.04). Despite presentation at higher average clinical stage in patients who underwent PC, at average follow up of 52 months, risk of IBTR and risk of regional recurrence were similar in the PC and no-PC groups (IBTR: 4.4% vs 3%, p = 0.99 and Regional: 1.5% vs. 1.5%, p = 0.99). Breast cancer specific survival was 86.5% in the PC group compared to 84% in the no-PC group (p = 0.68). Patients in the no-PC group were less likely to comply with recommended chemotherapy.Conclusions: In this underinsured, Hispanic population who did not use screening mammography, preoperative chemotherapy allowed many women to undergo breast conservation, undergo fewer operations, and were less likely to require ALND. Risk of local and regional recurrence is low in these patients and comparable to those who underwent primary operation.

Citation Format: Komenaka IK, Djenic B, Walters J, Hsu C-H, Nodora JN, Martinez ME, Bouton M, Mehta D. The benefit of preoperative chemotherapy in an underinsured Hispanic population with poor use of screening mammography. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-12-07.
Abstract P6-13-02: A phase 1 dose escalation study of RAD1901, an oral selective estrogen receptor degrader, in healthy postmenopausal women
Authors: Hattersley G , David F , Harris A , Clarkin M , Banks K , Glaudemans AWJM , Doorduin J , Koole M , de Vries EFJ , Williams G
Published: May 2016

Estrogen and the estrogen receptor (ER) are known to be prominent drivers of breast tumourigenesis and breast cancer progression. Hormonal agents that target the ER such as selective estrogen receptor modulators (SERMs) and selective estrogen receptor degraders (SERDs) are routinely used for the management for ER+ breast cancer. Fulvestrant is currently the only SERD approved for the treatment of ER-positive metastatic breast cancer, however, despite its clinical efficacy, the utility of fulvestrant has been limited by the amount of drug that can be administered in a single injection, the reduced bioavailability and the development of resistance in some patients. To overcome some of the challenges associated with current endocrine therapies there is a need for more durable and more effective ER-targeted therapies.

RAD1901 is a novel, non-steroidal, orally bioavailable SERD. Preclinical studies demonstrated a favorable tissue selectivity profile, dose dependent ER degradation and potent inhibition of in vitro breast cancer cell proliferation. Significant tumor regression was consistently observed with RAD1901 treatment, compared to Tamoxifen or Fulvestrant in MCF7 and patient derived xenograft models, including those harboring ESR1 mutations. Here we describe a Phase 1 clinical study that was conducted in 52 healthy postmenopausal female volunteers. Cohorts of 10 subjects (2 placebo, 8 RAD1901 treated) were dosed with 200 mg, 500 mg, 750 mg or 1000 mg for 7 days. Additional subjects were enrolled to an 18F-estradiol positron emission tomography (FES-PET) cohort to evaluate the 200 mg (n=7 subjects) and 500 mg (n=6 subjects) dose levels. All dose levels were generally well tolerated with a total of 43/52 subjects completing the study. Pharmacokinetic analysis demonstrated good plasma exposure with dose proportional increases. FES-PET was performed at baseline and after 7 days of treatment with RAD1901, to assess estrogen receptor engagement. Standardized uptake values (SUV) pre- and post-treatment demonstrated a complete attenuation of FES-PET signal in ER-rich tissues such as the uterus at the 500 mg/day dose level, whereas almost 80% reduction in the signal was observed at the 200 mg/day dose level. Based on these preclinical and clinical results, RAD1901 is currently being investigated in a Phase 1 study for the treatment of hormone driven and hormone resistant metastatic breast cancers.

Citation Format: Hattersley G, David F, Harris A, Clarkin M, Banks K, Glaudemans AWJM, Doorduin J, Koole M, de Vries EFJ, Williams G. A phase 1 dose escalation study of RAD1901, an oral selective estrogen receptor degrader, in healthy postmenopausal women. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-13-02.
Abstract P6-13-14: Temporospatial delivery of chemotherapeutics from nanoparticles for synergy enhancement
Authors: Segura-Ibarra V , Wu S , Cara FE , Meric-Bernstam F , Ferrari M , Blanco E
Published: May 2016

INTRODUCTION

Chemotherapeutic synergy enhancement can be obtained when drugs are delivered in a sequential manner. However, clinical translation of synergistic combinations is not feasible due to different pharmacokinetic properties arising from distinct drug formulations that negate proper sequential delivery. Our laboratory has developed a platform for temporospatial delivery of agents in a sequential fashion for purposes of enhancing site-specific synergy. The system comprises a drug-containing poly(lactic-co-glycolic acid) (PLGA) core and an outer shell of drug complexed with β-cyclodextrin (β-CD). In this study, we demonstrate the therapeutic potential of this nanoparticle system by encapsulating two drugs, rapamycin (RAP) and paclitaxel (PTX). This combination has been shown to result in cell-killing synergy enhancement in when administered sequentially, and in a time staggered manner, in triple negative breast cancer (TNBC) in in vitro cell-based models.

EXPERIMENTAL METHODS

The final platform was fabricated by resuspending PLGA-PTX nanoparticles in an aqueous solution of RAP cyclodextrin complexes (RAP-CD) under sonication. Nanoparticles were characterized for size and surface charge. Drug concentration and release kinetics were determined by HPLC. In vitro growth inhibition in SUM159 TNBC cells was determined via MTT assay. Western blotting was used to confirm target knockdown. For in vivo efficacy analysis, SUM159 breast cancer cells (3×106) were inoculated in the mammary fat pads of 4- to 6-week–old female nu/nu mice, and treatments were administered intravenously once a week for a duration of 21 days.

RESULTS AND DISCUSSION

Nanoparticles had a mean diameter of 140 nm and zeta potential of -30 mV. After complexation with RAP-CD, the surface charge became 25 mV. Release kinetics depicted a fast release of RAP at early timepoints, while PTX showed a prolonged release. Nanoparticles showed concentration dependent cell-killing efficacy in SUM159 breast cancer cells in vitro, with knockdown of pS6, characteristic of RAP treatment, observed. Upon administration of NNPs to murine models of TNBC, NNPs showed significant tumor growth inhibition compared to controls, and knockdown of pS6.

CONCLUSION

We have developed a novel nanoparticle for the temporospatial release of drugs. The ability to localize agents site-specifically and deliver them sequentially should enable clinical translation of synergistic regimens observed in in vitro scenarios, in turn yielding more efficacious more efficacious outcomes following combination chemotherapy.

Citation Format: Segura-Ibarra V, Wu S, Cara FE, Meric-Bernstam F, Ferrari M, Blanco E. Temporospatial delivery of chemotherapeutics from nanoparticles for synergy enhancement. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-13-14.
Abstract A04: Differential DNA methylation and network analysis in African American breast cancer
Authors: Yu Kaixian , Steppi Albert , Xu Yun , Tang Ke , Zhang Jinfeng
Published: May 2016

African Americans (AAs) have more severe breast cancer, and higher death rate from breast cancer, than that of Caucasian Americans (CAs) even after socioeconomic status are accounted for. Various studies have been done to understand the biological mechanism of this health disparity. In this study, we performed a genome-wide differential DNA methylation analysis between AA and CA breast cancer patients. We analyzed differentially methylated positions (DMPs) and differentially methylated regions (DMRs) using data from 143 AA and 554 CA breast tumor tissues available at the Cancer Genome Atlas (TCGA). We found that there were 1232 DMPs and 661 DMRs between AA and CA breast cancer patients. Both DMP and DMR showed that PACS2 and ATP1A4 were highly differentially methylated among other genes. Network analysis showed that differential methylation occurred significantly in p53, EGFR, and ERS1 subnetwork, which is consistent from an early study on differentially expressed transcripts. We also conducted a correlation analysis between gene expression by RNA sequencing and DNA methylation, which showed that expressions of 129 genes with either DMP or DMR were highly negatively correlated with the corresponding DNA methylations, suggesting that these DNA methylation may play important roles in the breast cancer health disparity observed in AA women. Our discoveries may help researchers to better understand the biological factors for breast cancer health disparity and the biology of breast cancer in general. The genes or DMPs/DMRs identified may serve as the starting points for further experimental validations towards discovering biomarkers for cancer diagnosis and prognosis, and drug targets for personalized treatments.

Citation Format: Kaixian Yu, Albert Steppi, Yun Xu, Ke Tang, Jinfeng Zhang. Differential DNA methylation and network analysis in African American breast cancer. [abstract]. In: Proceedings of the Eighth AACR Conference on The Science of Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; Nov 13-16, 2015; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2016;25(3 Suppl):Abstract nr A04.