bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract P3-04-27: Delineating novel molecular pathways driving endocrine resistance in breast cancer
Authors: Bosch A , Staaf J , Akrap N , Kaminska KK , Borgquist S , Borg Å , Honeth G
Published: March 2017

Background

Estrogen receptor (ER) is a main driver of tumor progression in ER+ metastatic breast cancer (MBC). The use of endocrine therapy can effectively control the disease in a large proportion of patients. However, the majority of MBC eventually become resistant and progress. To elucidate the mechanisms of acquired resistance to endocrine treatment is key in order to better select therapeutic partners and delay disease progression.

Methods

A panel of ER+ breast cancer cell lines initially sensitive to the selective estrogen receptor degrader (SERD) fulvestrant was exposed to increasing concentrations of this drug over several months to induce resistance. Cell proliferation was determined with the xCELLigence system. Protein expression was measured by phospho-kinase array and western blotting. RNA expression was evaluated by gene expression microarray analysis (Illumina) and validated by RT-qPCR. Cell cycle distribution was analyzed by flow cytometry.

Results

Using an unbiased approach to identify pathways that drive endocrine resistance, both the parental and the resistant cell models were studied. As expected, fulvestrant treatment resulted in G1-cell cycle arrest in the parental cell lines.

In stark contrast, resistant cells bypassed fulvestrant-induced proliferation block despite a lower expression of genes driving mitotic progression compared to untreated parental cells. This gene expression pattern was coupled with a reduction of ER protein level in the resistant cells, which was in line with a significant decrease in the expression of ER-target genes. Our phospho-screen analysis showed a genotype specific down-modulation of p53 and up-regulation of several signaling components of mitogenic pathways in resistant cells compared to parental cells.

Conclusions

Our results suggest that acquired endocrine resistance is driven by multiple cell-specific mechanisms rather than a common molecular underpinning. Strikingly, there is one unique feature in our models, which is a cellular switch towards an ER-independent gene expression program. Ongoing in vitro and in vivo studies, aimed at further characterizing these cellular models, will provide valuable insights into the heterogeneity underlying the response to endocrine treatment observed in MBC patients.

Citation Format: Bosch A, Staaf J, Akrap N, Kaminska KK, Borgquist S, Borg Å, Honeth G. Delineating novel molecular pathways driving endocrine resistance in breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-04-27.
Abstract P3-06-08: HDAC6 deacetylates HMGN2 to regulate Stat5a activity and breast cancer growth
Authors: Clevenger CV , Craig JM , Fiorillo AA , Feeney YB , Harrell JC , Medler TR
Published: March 2017

Stat5 is a transcription factor utilized by several cytokine/hormone receptor signaling pathways that promotes transcription of genes associated with proliferation, differentiation, and survival of cancer cells. However, there are currently no clinically approved therapies that target Stat5, despite ample evidence that it contributes to breast cancer pathogenesis. Previous research in our lab has shown that the high mobility group nucleosome binding domain 2 (HGMN2) protein serves as a Stat5 co-activator. The activity of HMGN2 has been previously shown to be regulated by acetylation. Here, we show that deacetylation of HMGN2 on lysine residue K2 by histone deacetylase 6 (HDAC6) promotes Stat5-mediated transcription and breast cancer growth. Conversely, in vitro HDAC6 inhibition by pharmacologic and knock-down approaches enhanced HMGN2 acetylation with a concomitant reduction of in vitro Stat5-mediated signaling and global gene expression, and breast cancer growth. In vitro and in vivo treatment of traditional and patient-derived xenograft models with HDAC6 inhibitors resulted in a highly significant reduction of tumor growth. Translationally, it was also found that high levels of acetylated K2 were present in normal human breast tissue, which was lost in primary breast cancers and lymph node metastases. This suggests that blockade of HMGN2 deacetylation as described above is a novel treatment for breast cancer, given that existing HDAC6 inhibitors have a favorable toxicity profile in Phase I trials of other tumor types. Altogether, these results reveal a novel mechanism through which HDAC6 regulates the transcription of Stat5 target genes and demonstrates the utility of HDAC6 inhibition as a potential breast cancer therapeutic.

Citation Format: Clevenger CV, Craig JM, Fiorillo AA, Feeney YB, Harrell JC, Medler TR. HDAC6 deacetylates HMGN2 to regulate Stat5a activity and breast cancer growth [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-06-08.
Abstract P3-06-09: Selection of presumed CD49f antagonists and their biological evaluation in breast cancer cells
Authors: Velasco-Velázquez M , Velázquez-Quesada I , Aguirre-Alvarado C , Guerrero-Rodríguez S , Ruiz-Moreno A , Ramirez-Salinas G , Segura-Cabrera A , Pérez-Tapia M
Published: March 2017

Breast cancer is the second cause of cancer death in women and the large majority of those deaths are due to drug resistance and/or recurrence. The cancer stem cell (CSC) model suggests that tumor stem-like cells play key roles in resistance and recurrence in breast cancer patients. Thus, CSCs have been pointed as targets for new anti-cancer therapies. CD49f is an integrin subunit that participates in the CSC-niche interaction. Knock-down of CD49f in breast cancer cells impairs mammosphere formation in vitro and tumorigenesis in vivo, suggesting that this protein is needed for maintenance of stemness.

Aiming to target breast CSC, we used consensus docking to select potential CD49f antagonists from a collection of 13,000+ drugs with previous clinical evaluations. Seven compounds with the lowest consensus Z score were selected for in vitro biological validation. Cell adhesion assays showed that four of the selected drugs (5193, 1382, 7631, and 12723) decrease the binding of CD49f+ MDA-MB-231 breast cancer cells to laminin, suggesting that those compounds antagonize the receptor. Mammosphere formation assays showed that compounds 5193, 1382, and 12723 limit the clonogenic capability of CD49f+ breast cancer cells in vitro. Compound 5193 was highly toxic in 2D cell viability assays. On the other hand, the clonogenic impairment produced by compounds 1382 and 12723 is independent of bulk cell line cytotoxicity, suggesting a direct impact on the CSC pool. The analyses of the effect of these drugs on the expression of breast CSC markers and CD49f-activated pathways are on their way.

Thus, we have identified some drugs that might be repurposed to target breast CSC. Since the pharmacokinetics and toxicology of those drugs is known, they could easily be ready for clinical trials. We demonstrated that in silico screening is useful to identify antagonists of receptors with relevant roles in breast CSC biology.

This work was supported by CONACYT 221105, PAPIIT-UNAM IN228616, and Red temática de células troncales y medicina regenerativa.

Citation Format: Velasco-Velázquez M, Velázquez-Quesada I, Aguirre-Alvarado C, Guerrero-Rodríguez S, Ruiz-Moreno A, Ramirez-Salinas G, Segura-Cabrera A, Pérez-Tapia M. Selection of presumed CD49f antagonists and their biological evaluation in breast cancer cells [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-06-09.
Abstract P3-07-16: ZBTB2 is a novel therapeutic target for cisplatin-resistance in metastatic breast cancer
Authors: Shin V , Siu MT , Cheuk I , Ho J , Chen J , Kwong A
Published: March 2017

Background: Zinc finger and BTB/POZ domain containing proteins (ZBTB) belong to a class of DNA-binding proteins that involved in development, differentiation and carcinogenesis. Our earlier findings showed that ZBTB2 expression was upregulated in cisplatin-resistant cells when compared with naïve cells. Increase in ZBTB2 expression was associated with ABCG2 drug transporter in drug resistance. However, the molecular mechanism of ZBTB2 in drug resistance and breast cancer metastasis remain largely unclear.

Methods: A cisplatin-resistant triple-negative breast cancer (TNBC) cell line, MDA-MB-231/cis, was used to examine the involvement of drug transporter genes and the drug resistance pathway. Stem cell related genes were studied by RNA-sequencing. Characterization of ZBTB2 on cell proliferation, invasion and epithelial-mesenchymal transition (EMT) process were performed in ZBTB2 siRNA transfected cells. Stem-like cells properties were validated using aldehyde dehydrogenase (ALDH) activity, tumorsphere formation ability and stem cell markers. Metastatic animal model was used to study the genetic changes during metastasis and associated with the findings in clinical samples.

Results: ZBTB2 has a higher expression in TNBC than other breast cancer subtypes. Also, the ZBTB2 expression is more prominent in primary breast tumor tissues when compared with non-tumor counterparts from TNBC patients. Silencing of ZBTB2 significantly reduced cell proliferation, invasion and sensitized cells to cisplatin through induction of apoptosis. Induction of ZBTB2 has been associated with breast cancer metastasis in mice model, where higher expression was seen in metastatic tumors when compared with primary tumors from tumor xenografts. ABCG2 and some epithelial-mesenchymal transition (EMT) markers (Twist 1, Snai2 and MMP-9) have been increased in metastatic tumors. Further, RNA sequencing analysis showed that ABCG2, IL6ST and FGFR1 were upregulated in MDA-MB-231/cis cells and downregulated in ZBTB2 siRNA transfected cells. Silencing of ZBTB2 reduced ALDH activity and tumorsphere formation ability. Treatment with inhibitor of NFkB (Bay11-7085) further decreased cell proliferation in cisplatin-resistant cells when compared with siZBTB2 alone. Expression of Stat3 and b-catenin were reduced upon knockdown of ZBTB2.

Conclusion: Taken together, silencing of ZBTB2 sensitize cancer cells to cisplatin through regulation of EMT markers and stem-like cell properties in TNBC. These findings suggest a novel molecular pathway targeting ZBTB2/stat3/NFkB signaling to combat drug resistance in metastatic TNBC.

Citation Format: Shin V, Siu MT, Cheuk I, Ho J, Chen J, Kwong A. ZBTB2 is a novel therapeutic target for cisplatin-resistance in metastatic breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-07-16.
Abstract P3-07-17: Squalene epoxidase is a potential metabolic oncogene by amplification with clinical implications in breast carcinoma: An in silico pan-cancer study with i
n vitro evidence
Authors: Zoppoli G , Brown D , Caffa I , Garuti A , Piras D , Gallo M , Isnaldi E , Nencioni A , Ballestrero A
Published: March 2017

This abstract was withdrawn by the authors.
Abstract P3-07-19: Dual inhibition of the MEK5 and PI3K pathways synergistically reduces proliferation and viability in triple negative breast cancer cells
Authors: Wright TD , Raybuck C , Wendekier K , Cavanaugh JE
Published: March 2017

Aberrations in the MAPK/extracellular signal-regulated kinase (MEK/ERK) and phosphoinositide-3-kinase (PI3K) pathways have been linked to increased proliferation and survival in triple negative breast cancer (TNBC) cells. It has been proposed that these survival characteristics are enhanced through compensatory signaling and crosstalk mechanisms. Promising combinations of MEK and PI3K inhibition have been evaluated in phase I clinical trials for various cancer types. However, these clinical trials have had limited efficacy and have yet to encompass the MEK5/ERK5 pathway, which has been shown to promote cell survival. The goal of this study was to examine the crosstalk between the MEK1/2, MEK5, and PI3K pathways and determine the most promising combination of the MEK1/2, ERK5, and PI3K inhibitors, U0126, XMD8-92, and LY294002, respectively, in a diverse panel of triple negative breast cancer cell lines: BT549, MDA-MB-231, and MDA-MB-468. Our results indicate that dual inhibition of the MEK5 and PI3K pathways significantly reduced proliferation (45.53%) in MDA-MB-231 TNBC cells. Also, the combination of MEK5 and PI3K inhibition was shown to be synergistic. In contrast, inhibition of ERK1/2 alone or in combination with PI3K or ERK5 inhibition yielded mixed responses. Additionally, treatment with LY294004 in MDA-MB-231 (ERK 5 KO) was more potent (IC50= 2.5 uM) than treatment in the native MDA-MB-231 cell line (IC50= 13.7 uM). These data suggest that crosstalk between these kinases occurs and dual inhibition of PI3K and ERK5 may be a novel therapeutic approach for treating TNBC.

Citation Format: Wright TD, Raybuck C, Wendekier K, Cavanaugh JE. Dual inhibition of the MEK5 and PI3K pathways synergistically reduces proliferation and viability in triple negative breast cancer cells [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-07-19.
Abstract P3-08-02: Multi-gene panel testing for hereditary cancer predisposition in unsolved high risk breast and ovarian cancer patients
Authors: Crawford BB , Adams SB , Sittler T , Van den Akker J , Chan SB , Leitner O , Ryan LN , Gil E , Van 't Veer LJ
Published: March 2017

Background

Among women with an elevated risk of hereditary breast and ovarian cancer who previously tested negative for pathogenic mutations in BRCA1 and BRCA2, a subset remain at increased risk of having hereditary breast, ovarian or other cancers, and should be offered multi-gene panel testing. We tested three groups of women who were enrolled in the UCSF Cancer Genetics and Prevention Program: (i) 97 women with a personal history of bilateral breast cancer, (ii) 104 women with a personal history of breast cancer and a first-degree or second-degree relative with ovarian cancer, and (iii) 99 women with a personal history of ovarian, fallopian tube, or primary peritoneal cancer. All women previously tested negative for pathogenic BRCA1 and BRCA2 mutations by either limited or comprehensive testing.

Methods

We performed comprehensive next-generation sequencing using a panel of 19 genes developed by Color Genomics (a CLIA-certified laboratory) covering ATM, BARD1, BRCA1, BRCA2, BRIP1, CDH1, CHEK2, EPCAM, MLH1, MSH2, MSH6, NBN, PALB2, PMS2, PTEN, RAD51C, RAD51D, STK11, and TP53.

Results

Across the groups tested, 9% had pathogenic mutations in one or more of the genes analyzed (8% in genes other than BRCA1 and BRCA2). Among these women, Ashkenazi Jewish and Hispanic women had elevated mutation rates compared to those of other ethnicities. In addition, we identified two women with pathogenic mutations in two cancer susceptibility genes, which has significant implications for family testing. These results demonstrate the importance of genetic testing of genes other than BRCA1 and BRCA2.

Conclusions

Among women with an elevated risk of hereditary breast and ovarian cancer who have previously tested negative for BRCA1 and BRCA2 mutations, we propose that women with characteristics of any of the three groups above be considered for subsequent multi-gene panel testing. Additionally, ethnicity and the possibility of multiple mutations may be indications for additional testing in these women and in family members of carriers.

Citation Format: Crawford BB, Adams SB, Sittler T, Van den Akker J, Chan SB, Leitner O, Ryan LN, Gil E, Van 't Veer LJ. Multi-gene panel testing for hereditary cancer predisposition in unsolved high risk breast and ovarian cancer patients [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-08-02.
Abstract P3-10-08: Socio-demographic predictors for delay of treatment among a racially diverse, urban breast cancer population
Authors: Ko NY , Patts G , Battaglia TA , Wang C , Denis GV , Hirsch A , Weinberg J
Published: March 2017

Background:

Racial and ethnic disparity in breast cancer outcomes is a long-standing problem that continues to worsen. Recent evidence has underscored the importance of timely care, as delays in treatment can lead to decreased survival. We sought to understand predictors of delay to first treatment among a racially diverse cancer population.

Methods:

This is a retrospective study of breast cancer cases diagnosed between the years 2000 to 2014. Data was extracted from the cancer registry at Boston Medical Center (BMC), an urban safety net hospital. Inclusion criteria were any breast cancer diagnosis from 2000-2014, receiving first treatment at BMC, and disease stage 0-III. Cox Proportional Hazards regression analysis was performed to identify predictors of time to first treatment, defined as days from date of diagnosis to date of first treatment with surgery or neo-adjuvant chemotherapy. Covariates included age, sex, race, type of insurance, marital status, US birth, disease stage and year of diagnosis.

Results:

Patients were 99% female and with a mean age of 58 years (range 23-96). Among a sample of 1545 breast cancer cases, 1372 (89%) had surgery as first treatment and 173 (11%) had neoadjuvant chemotherapy. Median days to treatment was 45 days (IQR 27, 71). In the multi-variable adjusted models for both treatment groups, race, and insurance were significantly associated with delay. In the surgical group, Black race, public or no insurance, non-US born, later stage and unmarried status were associated with increased risk of delay. For example, Blacks were at higher risk for delay (HR= 1.2; 95% CI 1.37-1.04) compared to the Hispanic or White (reference) groups. Public insurance (HR = 1.19; 95%CI 1.37-1.04) and no insurance (HR = 1.43; 95%CI 1.85-1.09) was significantly associated with increased delay when compared to private insurance (reference). In patients with neoadjuvant chemotherapy as first treatment, additional significant predictors of delay were age and year of diagnosis.

Conclusion:

Race and insurance status were significant predictors of delay to first treatment in a population of diverse breast cancer patients seeking care at a safety net hospital. Intervention efforts need to target patients at greatest risk for treatment delays.

Citation Format: Ko NY, Patts G, Battaglia TA, Wang C, Denis GV, Hirsch A, Weinberg J. Socio-demographic predictors for delay of treatment among a racially diverse, urban breast cancer population [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-10-08.
Abstract P3-13-23: Predicting residual disease in breast conservative surgery after neoadjuvant treatments in breast cancer patients using the margin index tool
Authors: Rubio IT , Loinaz I , Esgueva-Colmenarejo AJ
Published: March 2017

Background. The appropriate surgical margin after neoadjuvant treatment (NAT) is controversial. Margin index, a relationship of the margin obtained to the size of the tumor, is a reliable method for the prediction of residual disease after breast conservative surgery (BCS) in the adjuvant setting. Our aim was to apply the margin index to patients with BCS after NAT to predict residual disease.

Material and Methods. From a prospectively maintained database, patients with stage I - III with NAT who underwent BCS between July 2008 and December 2012 were included. Margin index was calculated as for the adjuvant setting: margin index = closest margin (mm)/tumor size (mm) × 100 considering the tumor size of the lumpectomy specimen. A receiver operating curve was created using the derived margin index and the presence or absence of residual disease in the re-excision specimen. Patients with pathologic complete response (pCR) (no invasive tumor) were excluded.

Results. Of the 206 patients, 63 (30.5%) had a pCR and were excluded. Of the 143 patients, 76 (53%) had an intraoperative re-excision depending on the surgeon or the intraoperative pathology report. Of the 76 patients, 23 (32%) had residual tumor in the intraoperative re-excision specimen. There were no statistically significant differences in residual disease regardless of who indicates intraoperative re-excision. (p= 0.56) Twenty-three patients (16%) underwent a second surgery for positive or close margins ( < 2mm). Residual disease, whether infiltrating or in situ or both, was found in 10 (43%) patients. The overall c index for the receiver operating curve was 0.76. A margin index > 5 had a sensitivity of 80% and a specificity of 63%.

Conclusion. Rates of re-excision after NAT in BCS patients are similar to the adjuvant setting. Margin index may be a valuable tool for determine residual disease after NAT in patients undergoing BCS. Further validation of this index is warranted in a larger cohort of patients after NAT to confirm these results.

Citation Format: Rubio IT, Loinaz I, Esgueva-Colmenarejo AJ. Predicting residual disease in breast conservative surgery after neoadjuvant treatments in breast cancer patients using the margin index tool [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-13-23.
Abstract P3-14-01: International validation of the EORTC patient-reported outcome measure (PROM) in breast reconstruction (BRR): The EORTC QLQ-BRECON23 evaluating the psychometric properties and clinical effectiveness
Authors: Winters ZE , Afzal M , Rutherford C , Holzner B , Rumpold G , da Costa Vieira RA , Hartnup S , Filcroft K , Bjelic-Radisic V , Oberguggenburger A , Panouilleres M , Mani MR , Catanuto G , Douek M , Kokan J , King MT
Published: March 2017

This abstract was withdrawn by the authors.
Abstract P3-17-02: Gene expression differences between ductal carcinoma in situ with and without progression to invasive breast cancer
Authors: Doebar SC , Sieuwerts AM , de Weerd V , Martens JWM , van Deurzen CHM
Published: March 2017

Background

The mechanism behind progression of ductal carcinoma in situ (DCIS) to invasive breast cancer (IBC) remains unknown. The aim of our study was to increase our understanding regarding molecular alterations driving DCIS progression by comparing gene-expression patterns between patients with pure DCIS and patients with synchronous DCIS and IBC.

Methods

In this retrospective study, we included patients with extensive pure DCIS (n=12), defined as > 5 cm, as a representation of biologically indolent lesions with limited invasive capacity. These cases were matched with patients with a limited DCIS component, defined as < 1 cm, and synchronous IBC (n=12), representing lesions with a high invasive potential. Matching was based on age and surrogate DCIS subtypes. Gene expression profiling, using 93 tumor-specific target genes, was performed to identify transcriptional differences between the DCIS components of these two groups. The identified genes were validated by immunohistochemistry.

Results

In total, for 9 genes there was a significant difference in gene expression between patients with pure DCIS and patients with DCIS and synchronous IBC. The majority of these 9 genes were significantly higher expressed in DCIS samples with IBC, including PLAU (P=0.002), COL1A1 (P=0.006), KRT81 (P=0.009), S100A7 (P=0.015), SCGB1D2 (P=0.023), KRT18 (P=0.029) and NOTCH3 (P= 0.044), while EGFR and CXCL14 showed a significantly higher expression in pure DCIS (P=0.015 and P=0.028 respectively). Based on these 9 genes, unsupervised hierarchical clustering-analysis revealed distinct clustering of patients with pure DCIS and patients with DCIS and synchronous IBC. Immunohistochemical analyses are in progress.

Conclusion

This pilot study suggests that patients with pure DCIS have a significant different gene expression pattern as compared to patients with DCIS and synchronous IBC. If these results can be validated in an independent cohort, these differently expressed genes could be used to predict progression in individual patients diagnosed with DCIS. Furthermore, these genes may pinpoint driver pathway(s) that play an important role in the progression of DCIS to IBC.

Citation Format: Doebar SC, Sieuwerts AM, de Weerd V, Martens JWM, van Deurzen CHM. Gene expression differences between ductal carcinoma in situ with and without progression to invasive breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-17-02.
Abstract P4-02-09: Non-invasive and low-cost technique for early detection of clinically relevant breast lesions using a handheld point-of-care medical device (iBreastExam): Prospective three-arm triple-blinded comparative study for breast cancer screening in low resource setting countries
Authors: Somashekhar SP , Ashwin KR
Published: March 2017

This abstract was not presented at the symposium.
Abstract P4-03-07: Inhibition of cancer-associated fibroblast function by farnesoid X receptor activation: Experimental basis for a novel therapeutic strategy in breast cancer
Authors: Barone I , Vircillo V , Giordano C , Tarallo R , Rinaldi A , Bruno G , Bonofiglio D , Catalano S , Ando' S
Published: March 2017

This abstract was withdrawn by the authors.
Abstract P4-03-16: FAPα (fibroblast activation protein-α) analysis in breast tumor cells and stroma after neoadjuvant treatment
Authors: Calvo I , Prieto M , Suárez-Gauthier A , Pérez FJ , Hernández E , Acosta D , Cárdenas JM , López-Ríos F , Estévez LG
Published: March 2017

Background: FAPα is a transmembrane serine protease expressed on cancer associated fibroblast that promotes tumour growth and invasion. In patients (pts) with poor outcome and survival FAPα is highly overexpressed. FAPα is also expressed in stroma across all breast cancer subtypes without association with clinicopathological factors. Pts without Complete Pathological Response (pCR) after Neoadjuvant Chemotherapy (NC) had poor outcome. We analysed the relationship between the expression of FAPα in stroma (fibroblast) and in epithelial breast cancer cells of pts without pCR after NC (taxanes, antracyclines and trastuzumab in Her2+).

Methods: 60 pts were included. ER, PR and Ki67 were studied by IHQ (Ventana) and Her2 by FISH (PatnVysion). FAPα expression was determined by IHQ (polyclonal, Ventana). St Gallen guidelines for subtype of breast cancer were used.

Results: 53 pts had tissue. Median age 47 years (range 29-68). Median tumour size 43mm and 10 (18.9%) were multifocal. 37 (69.8%) had positive axillary nodes. 47 were ductal invasive carcinomas. 33 (62.3%) were grade 2 and 20 (37.7%) grade 3. 44 pts (83%) had ER+ (20 luminal B), 17 (32%) Her2+ and 6 (11%) triple negative(TN). Median Ki67 was 22% (p25-75:15-38%). Miller-Payne response was 1.9% G1 (1pt), 43.4% G2 (23 pts), 41.5% G3 (22 pts) and 13.2% G4 (7 pts). The recurrences were 2 local and 12 distant (26.4%). Median FAPα in residual epithelial breast cancer cells after NC was 85% (p25-75:30-95%) and in the stroma 20% (p25-75:10-62%). Median epithelial FAPα was 55% in TN, 85% Her2, 72.5% luminal A and 92.5% in luminal B. Median stromal FAPα was 52.5% in TN, 20% Her2, 15% luminal A and 15% in luminal B. There is not association between stromal FAPα and clinicopathological features, but a higher epithelial FAPα was found in tumours wih higher ER, PR and Ki67. In luminal B subtype, stromal FAPα was smaller in pts with relapses (median 7.5%) than without relapses (median 30%). Conclusions: Stromal FAPα in residual cancer after NC is higher in TN breast cancer but without association with relapses in our small sample. However, in luminal B subtype stromal FAPα is smaller in pts with relapses.

Citation Format: Calvo I, Prieto M, Suárez-Gauthier A, Pérez FJ, Hernández E, Acosta D, Cárdenas JM, López-Ríos F, Estévez LG. FAPα (fibroblast activation protein-α) analysis in breast tumor cells and stroma after neoadjuvant treatment [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-03-16.
Abstract P4-07-09: Differential expression of microRNAs (miRNAs) in HER2 negative breast cancer (BC)
Authors: Pascual T , Gámez-Pozo A , Camara-Jurado M , Manso LM , Pérez-Campos A , Trilla L , Fresno-Vara JA , Ciruelos EM
Published: March 2017

Background:

MiRNAs are non-coding single-stranded RNAs that control gene expression by directing their target mRNAs for degradation and/or posttranscriptional repression. Compared to mRNA signatures, miRNAs have better and stronger biomarker properties with 20 times more power in biomarker studies as compared to mRNAs (when comparing 20,000 mRNAs to ~ 1,000 miRNAs). Global downregulation of miRNAs has emerged as a common theme in human breast tumors and has been shown to contribute to oncogenesis

Hormone receptor (HR) status is one of the most important factors influencing BC outcome. Several data indicate the extensive alterations in miRNAs regulation upon estrogen pathway and suggest the utility of considering miRNAs expression in the understanding the development of cancer disease, invasiveness, metastasis and treatment failure.

Our aim was to identify differential expression miRNAs in HER2 negative BC. We previously reported a set of miRNAs deregulated in HR+/HER2- BC vs. Triple negative BC (TNBC). In this work we have validate these differences in a new cohort of BC patients.

Methods:

Total RNA was extracted samples extracted from primary breast cancer FFPE tissue. MicroRNAs expression was analyzed by RT-qPCR using TaqMan Arrays from Applied Biosystems. Normalization was performed using de DCt method with two housekeeping miRNAs identified previously identified using NorMean. MicroRNA expression values in each group were compared by the Mann Whitney test.

Results:

121 patients with early HER2 negative BC were included in the present study. All patients showed absence of nodal involvement at the time of diagnosis. The median age at diagnosis was 56 years, 89 cases (74%) had positive estrogen receptor and 53 cases (44%) grade 3. miR-20a, miR-19a, miR-106a, miR-18a and miR-135b expression were significantly higher in TNBC samples, whereas miR-190b, miR-375, miR-449a, miR-342, miR-149, miR-193b, miR-214, miR-30a*and miR-30e* were significantly more expressed in ER+/HER2- samples. No significant differences were found in miR-139-5p expression between both groups.

Conclusions:

We have validated fourteen miRNAs that are differentially expressed between ER+/HER2- and TNBC breast cancer subtypes. Altered expression of miRNAs could be a potential therapeutic tool and promising biomarker in personalized treatment.

Citation Format: Pascual T, Gámez-Pozo A, Camara-Jurado M, Manso LM, Pérez-Campos A, Trilla L, Fresno-Vara JA, Ciruelos EM. Differential expression of microRNAs (miRNAs) in HER2 negative breast cancer (BC) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-07-09.
Abstract P4-08-02: Integration of transcriptomic, proteomic and drug response data in triple negative breast cancer cell lines and PDX models
Authors: Mills CE , Hafner MA , Sorger PK
Published: March 2017

Drug response screens on panels of cell lines aimed at identifying markers of sensitivity or resistance have been limited in their successes. Unfortunately, the recent release of many such studies has been accompanied by concerns surrounding reproducibility. Since then, several publications have addressed these concerns by pointing out sources of variability and by suggesting better experimental methods as well as more robust analytical approaches. In the presented profiling effort, we integrated the latest advances in drug response measurement and focused on data diversity and quality rather than on breadth. We selected 32 breast cancer cell lines with a strong bias towards triple negative lines as well as 4 cell lines established from relevant patient-derived xenografts. We used high content microscopy to assay the phenotypic responses of the cell lines to a panel of 34 drugs made up largely of kinase inhibitors currently in the clinic along with some standard of care chemotherapeutics. The microscopy based drug response assay allowed us to measure drug potency, and to quantify the efficacy of the drugs in terms of growth inhibition and cell death. For the same cell lines, we used RNAseq to measure basal mRNA expression levels and shotgun mass spectrometry to measure endogenous protein levels.

The completeness and controlled conditions under which these data sets were collected provide confidence in their integration. The complementarity of these multi-omics data has allowed us to address questions about the landscape of, particularly triple negative, breast cancer cell lines. Such questions include: where do the patient-derived lines lay among the established cell lines? and how different are the landscapes defined by drug response phenotypes, mRNA expression, and protein levels? We used network-based algorithms to identify eigenstates of signaling pathways related to genomic events, and further explored these states in the TCGA data.

At the level of drug response, we have focused on important questions related to the clinical use of kinase inhibitors. In particular, we compared various CDK inhibitors in an effort to identify markers that are informative of response potency and efficacy. We have also looked at variability of the responses of the cell lines studied to multiple PI3K inhibitors that either target specific isoforms or all isoforms. Overall the data set that has been collected is a valuable resource for understanding drug response in triple negative breast cancer, and the transcriptomic and proteomic factors that influence it.

Citation Format: Mills CE, Hafner MA, Sorger PK. Integration of transcriptomic, proteomic and drug response data in triple negative breast cancer cell lines and PDX models [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-08-02.
Abstract P4-09-01: Tumor suppressor control of the cancer stem cell angiogenic niche
Authors: Crowe D , Kramer K , Wu J
Published: March 2017

Mammary stem cells (MSC) expansion is associated with aggressive human breast cancer. The nuclear receptor peroxisome proliferator activated receptor γ (PPARγ) is a breast cancer tumor suppressor, but the mechanisms of this suppression are not completely characterized. To determine if PPARγ regulates MSC expansion in mammary cancer, we deleted PPARγ expression in the mammary epithelium of an in vivo model of basal breast cancer. Loss of PPARγ expression reduced tumor latency, and expanded the CD24+/CD49fhi MSC population. PPARγ null mammary tumors exhibited increased angiogenesis which was detected in human breast cancer. In vivo inhibition of a PPARγ regulated miR-15a/angiopoietin-1 pathway blocked increased angiogenesis and MSC expansion. PPARγ bound and activated a canonical response element in the miR-15a gene. PPARγ null tumors were sensitive to the targeted anti-angiogenic drug sunitinib but resistant to cytotoxic chemotherapy. Normalization of tumor vasculature with sunitinib resulted in objective response to cytotoxic chemotherapy. Chemotherapy treated PPARγ null mammary tumors exhibited luminal phenotype and expansion of unipotent CD61+ luminal progenitor cells. Transplantation of chemotherapy treated luminal progenitor cells recapitulated the luminal phenotype. These results have important implications for anti-angiogenic therapy in breast cancer patients.

Citation Format: Crowe D, Kramer K, Wu J. Tumor suppressor control of the cancer stem cell angiogenic niche [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-09-01.
Abstract P4-12-15: Triple-negative breast cancers (TNBCs) rich in infiltrating stromal plasma cells have improved disease-free survival and overall survival
Authors: McIntire PJ , Cui X , Ginter PS , Irshaid L , Chen Z , Shin SJ
Published: March 2017

Background Tumor-infiltrating lymphocytes (TILs) have emerged as a prognostic indicator in patients with TNBC. Furthermore, lymphocyte-predominant breast cancer (LPBC), defined as those containing ≥50% stromal TILs has been shown to be associated with better prognosis. While cell-mediated immunity has received much of the credit for anti-tumor responses, the International TILs Working Group recommends that the assessment of stromal density of TILs should incorporate all mononuclear cells including plasma cells. Very little is known about the role of humoral immunity, particularly the role of plasma cells in the anti-tumoral response in breast cancer. We sought to evaluate the prognostic value of plasma cells in the setting of stromal TIL assessment of TNBC. Design Morphologic assessment of TILs was performed on a representative H&E slide of 76 cases of primary TNBC. For each case, the stromal density of TILs was estimated and then classified as LPBC or non-LPBC using a cutoff of ≥50% for the former. Also, the plasma cell intensity defined as the mean percentage of stromal plasma cells of five 40x high power microscopic fields of TILs was recorded at 5% increments. Statistical analyses were performed using disease-free survival (DFS) and overall survival (OS) (range: 16 to 196 months, mean: 110 months) as primary endpoints. Results Plasma cell intensity was dichotomized at 12.5% and predictive of OS [.21, 95% confidence interval (CI) .05-.93, P = 0.0401)]. A positive dose related response trended toward significance for each 5% increase in plasma cell intensity (.97, 95% CI .93-1.01, P = 0.1168). Disease-free survival also trended positively towards significance (.39, 95% CI .13-1.20, P = 0.0991). When comparing LPBC, tumors rich in plasma cells (>12.5% of TILs) trended towards longer DFS (.17, 95% CI .02-1.62, P = 0.1226) when compared to plasma cell poor LPBC. Conclusion In addition to the cell-mediated immune response in TNBC, our findings suggest that humoral immunity may also play a role in predicting recurrence and survival in these patients. Our findings suggest that inclusion of an additional parameter of plasma cell intensity may be prognostically valuable in TIL assessment of TNBC.

Citation Format: McIntire PJ, Cui X, Ginter PS, Irshaid L, Chen Z, Shin SJ. Triple-negative breast cancers (TNBCs) rich in infiltrating stromal plasma cells have improved disease-free survival and overall survival [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-12-15.
Abstract P4-21-33: HER2 activity regulates the pro-trastuzumab immune tumor microenvironment
Authors: Tagliabue E , Forte L , Regondi V , Ghirelli C , Aiello P , Triulzi T
Published: March 2017

It is well know that trastuzumab activity against HER2-positive breast carcinomas (BCs) depends also on immune cells. Our genomic analysis of 53 HER2-positive BCs indicated that those exquisitely sensitive to treatment are addicted to this oncoprotein and are enriched in immune pathways and T-cells infiltration, raising the hypothesis that HER2 regulates immune cells recruitment. The aim of this study was to investigate how HER2 activity contributes to mold tumor microenvironment.

Gene expression profile analysis of 53 HER2-pos BCs showed that trastuzumab-sensitive tumors express significantly higher levels of chemokines involved in immune cells recruitment (IFNγ-related CXCLs and CCLs) and higher levels of immune checkpoint ligands (PD-L1, PD-L2) than tumors that do not benefit from trastuzumab. Immunohistochemistry analysis on FFPE tumor specimens showed a significant positive association between tumor cell positivity for CXCL9, CXCL10 and CCL2 and trastuzumab sensitivity. In vitro analysis in HER2-positive BC cell lines revealed that while IFNγ-related chemokines (CXCL9 and CXCL10) are not directly regulated by HER2 signaling, CCL2 was significantly up-regulated both at mRNA and protein levels by HER2 stimulation with EGF/HRG and down-modulated by HER2 inhibition with trastuzumab. The EGF-induced increase in CCL2 expression was abrogated by the concomitant treatment with PI3K inhibitor but not with MEK inhibitor, indicating that HER2 regulates CCL2 expression via the PI3K pathway. HER2 signals derived from cell stimulation with EGF/HRG caused also the upmodulation of PD-L1/PD-L2 both at mRNA and protein levels while their inhibition with trastuzumab reduced their levels.

Overall, our results support the notion that the activated HER2 oncogene concomitantly induces the expression of CCL2 and PD-L1/PD-L2 regulating infiltration of pro-trastuzumab immune cells and their suppression. Thus, it is likely that activity of trastuzumab in therapy-responsive tumors derives from its ability in relieving suppression of recruited antitumor effector immunity.

Supported by Italian Association for Cancer Research (AIRC).

Citation Format: Tagliabue E, Forte L, Regondi V, Ghirelli C, Aiello P, Triulzi T. HER2 activity regulates the pro-trastuzumab immune tumor microenvironment [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-21-33.
Abstract P5-06-04: Distinct BRCA1 and BRCA2 specific functions at stalled replication forks - Clinical implications for differences between BRCA1 and BRCA2 mutation driven cancer
Authors: Pathania S , Reed R , Duan H , Culhane A , Garber J
Published: March 2017

This abstract was withdrawn by the authors.
Abstract P5-10-09: Prospective cross-sectional-study on participation in mammography screening according to immigration background and education status
Authors: Kuehnle E , Oeztuerk T , Siggelkow W , Luebbe K , Moser A , Noeding S , John J , Noesselt T , Busch C , Arfsten M , Lemster S , Hillemans P , Doerk T , Park-Simon T-W
Published: March 2017

Introduction

Although the health of immigrants is an important issue in national health care policy there is a serious shortage of data in many countries. Most studies lack information on educational status which is a major limitation. In this prospective cross-sectional-study we analyzed the influence of immigration background and educational status on the participation in mammography screening programs in Lower-Saxony, Germany.

Material and methods

Data collection was conducted from 2012-2016 in six certified breast cancer centers using a personal questionnaire and data from the patients' medical records. Stratification into subgroups was carried out according to first and second generation immigrants and country of origin.

Results

1547/2129 primary breast cancer cases were analyzed. The percentage of patients with a history of immigration in our study cohort was 17.7%. The majority of them were citizens of EU27 Member states. First generation immigrants (n= 146), second generation immigrants (n=129), natives (n= 1272). No significant difference was seen in sex, age, tumor stage, histology, grading, Ki-67, Her2/neu-status, and hormone receptor status. A 100% participation rate in the mammography screening program was seen in patients with no school graduation. The lowest participation rate (85.5%) was seen in the group of native Germans with a college graduation and in first generation immigrants with a high school graduation (86.7%). Detailed statistical analysis will be presented on the poster.

Conclusion

No difference was seen between immigrants and native Germans with regard to tumor biology. In first-generation immigrants mammography screening was well accepted despite cultural and linguistic differences. Participation rate decreased with higher education level in all groups. High school graduates with immigrant background participated more frequently in breast cancer screening than native high school graduates. These findings mainly relate to immigrants from EU27 Member states rather than immigrants from non EU countries.

Citation Format: Kuehnle E, Oeztuerk T, Siggelkow W, Luebbe K, Moser A, Noeding S, John J, Noesselt T, Busch C, Arfsten M, Lemster S, Hillemans P, Doerk T, Park-Simon T-W. Prospective cross-sectional-study on participation in mammography screening according to immigration background and education status [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-10-09.
Abstract P5-13-01: Sociodemographic and economic factors are essential determinants of weight gain between before and after cancer diagnosis: Results from the prospective population-based NutriNet-Santé cohort
Authors: Fassier P , Zelek L , Partula V , Lecuyer L , Srour B , Bachmann P , Touillaud M , Druesne-Pecollo N , Galan P , Hercberg S , Cohen P , Hoarau H , Latino-Martel P , Gonzalez R , Deschasaux M , Touvier M
Published: March 2017

Background: While many cancer patients are affected by weight loss, others tend to gain weight, which may impact prognosis and risk of recurrence and of second cancer. The aim of this prospective study was to investigate weight variation between before and after cancer diagnosis and socio-demographic, economic, lifestyle and clinical factors associated with moderate-to-severe weight gain.

Methods: 1051 incident cases of first primary cancer were diagnosed in the NutriNet-Santé cohort between 2009 and 2015. Weight was prospectively collected every 6 months since subjects' inclusion (i.e. an average of 2y before diagnosis). Mean weights before and after cancer diagnosis were compared with paired Student's t-test. Factors associated with moderate-to-severe weight gain (≥5% of initial weight) were investigated by multivariable logistic regression.

Results: Weight loss was observed in men (-3.54kg in those who lost weight, p=0.0002) and in colorectal cancer patients (-3.94kg, p=0.0012). Weight gain was observed in breast and skin cancers (2.83kg, p=0.047, and 2.96kg, p=0.03 respectively). Women (OR=1.99[1.18-3.35]), younger patients (OR=1.78[1.05-3.03]), those with lower education (OR=2.17[1.07-4.37]), those with excess weight before diagnosis (OR=1.53[1.02-2.30]) and those who stopped smoking after diagnosis (OR=4.60[2.06-10.25]) were more likely to experience moderate-to-severe weight gain. In breast cancer patients, induced menopause was associated with weight gain (OR=4.12[1.76-9.67]), but no association was detected for tumor characteristics or treatments.

Conclusion: This large prospective cohort provided original results on weight variation between before and after cancer diagnosis, highlighting different weight trajectories. Socio-demographic and economic factors appeared to strongly influence the risk of weight gain, illustrating social inequalities in health.

Citation Format: Fassier P, Zelek L, Partula V, Lecuyer L, Srour B, Bachmann P, Touillaud M, Druesne-Pecollo N, Galan P, Hercberg S, Cohen P, Hoarau H, Latino-Martel P, Gonzalez R, Deschasaux M, Touvier M. Sociodemographic and economic factors are essential determinants of weight gain between before and after cancer diagnosis: Results from the prospective population-based NutriNet-Santé cohort [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-13-01.