bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract P4-06-02: Insulin receptor targeting in breast cancer through yeast surface display
Authors: Chan Jie Ying , Hackel Benjamin , Yee Douglas
Published: May 2015

Selective estrogen receptor modulators (SERMs) such as tamoxifen have been a conventional therapy for breast cancer patients expressing estrogen receptor, representing the most common breast cancer type. The development of secondary resistance to SERM is an unsolved clinical dilemma, leading to the exploration of more targeted therapies. The insulin-like growth factor (IGF) system is well documented and is implicated as a contributor to endocrine resistance. Unfortunately, antibodies directed against type I IGF receptor (IGF1R) failed to demonstrate efficacy in endocrine resistant breast cancer. We have previously shown that tamoxifen resistant (TamR) breast cancer cells lose IGF1R yet retain expression of insulin receptor (InsR), a closely related receptor to IGF1R. Thus, we hypothesized that InsR may serve as a compensatory pathway to the loss of IGF1R in TamR cells and InsR may be a target in the therapy of endocrine resistant breast cancer. Indeed, our preliminary results show that TamR breast cancer cells were more sensitive to insulin stimulation. As compared to the parental cells, TamR cells showed stronger PI3K/AKT and MAPK/ERK activation, greater MTT proliferation growth and anchorage-independent growth upon insulin treatment. Knocking down InsR in TamR cells with shRNA was able to attenuate their sensitivity towards insulin-mediated PI3K/MAPK activation and growth, suggesting InsR targeting may be necessary in endocrine resistant breast cancer. To develop new agents to target InsR, we used yeast surface display to develop an InsR-selective protein scaffold – the 10th type III domain of human fibronectin (Fn3). This technique has arisen as an alternative method for the development of specific binders of cell surface proteins. Compared to antibodies, the Fn3 proteins are smaller (∼10kDa), thermally more stable, lack disulfide bonds and have the ability to bind a large variety of proteins. Using error-prone polymerase mutagenesis, we identified improved Fn3 proteins with increased InsR affinity, specificity, and stability. Our current results show that InsR is an important target in endocrine resistant breast cancer cells. Development of engineered Fn3 peptides with increased InsR binding specificity and affinity for InsR compared to IGF1R could be used to disrupt signaling through this pathway. Engineered Fn3 will further be evaluated as a potential imaging and therapeutic tool.

Citation Format: Jie Ying Chan, Benjamin Hackel, Douglas Yee. Insulin receptor targeting in breast cancer through yeast surface display [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P4-06-02.
Abstract P4-06-04: Targeting the PI3K-AKT-mTOR and RAF-MEK-ERK pathways in HER2 amplified breast cancer models
Authors: De Pradip , Sun Yuliang , Carlson Jennifer , Friedman Lori , Dey Nandini , Leyland-Jones Brian
Published: May 2015

Background: The PI3K-AKT-mTOR and the RAF-MEK-ERK signaling pathways are critical for normal physiology and also commonly dysregulated in several cancers including breast cancer. Inhibition of one pathway can still result in the maintenance of signaling and tumor progression via the other reciprocal pathway. Here, we hypothesize that due to the existence of such "escape" mechanisms a dual targeting of these pathways may lead to superior therapeutic activity in HER2+ breast tumors. Methodology: This study evaluated the combination of a pan-PI3K inhibitor GDC-0941 and a MEK1/2 inhibitor GDC-0973 in different HER2+ breast cancer cell lines. HER2+/trastuzumab (T)-sensitive (BT474), HER2+/trastuzumab-resistant (BT474HerR) and HER2+/PIK3CA mutated (HCC1954) cells were used for this study. Growth inhibition/survival, apoptosis, signal transduction and antitumor efficacy were examined using 3D-ON-TOP assays, annexinV staining and mouse xenografts respectively, in T-sensitive, T-resistant and HER2+/PIK3CA mutated breast cancer cell lines. Results: 1) treatment with GDC-0941 caused dose dependent inhibition of phosphorylation of AKT (S473, T308), P70S6K, S6RP, and 4EBP1 (T37/46) and the combination of GDC-0941 plus GDC-0973 more effectively blocked p-S6RP and p-4EBP1, especially in BT474HerR and HCC1954 cells, 2) GDC-0973 inhibited activation of ERK and this inhibition was sustained when combined with GDC-0941, 3) all cell lines showed an increase in annexin V positivity (index of apoptosis) following the treatment of GDC-0941 alone and a combination of GDC-0941 plus GDC-0973 more effectively induced apoptosis in HER2+ cell lines, 4) similar to anti-proliferative and pro-apoptotic signals, a combination of GDC-0941 plus GDC-0973 more effectively abrogated anchorage-independent colony formation in 3D-ON-TOP assay and 5) xenograft data exhibited that the combination of T plus GDC-0941 has an enhanced anti-tumor effect in T-sensitive (80%), T-resistant (82%) and PIK3CA mutated models (58%), and most importantly, tumor regression was more pronounced in all three models when mice were treated with T plus GDC-0941 plus GDC-0973. Conclusions: Our findings suggest that simultaneous administration of MEK1/2 inhibitor may enhance the antitumor activity of PI3K targeted drug and may delay the appearance of resistance of HER2-targeted therapy in HER2 amplified breast cancer.

Citation Format: Pradip De, Yuliang Sun, Jennifer Carlson, Lori Friedman, Nandini Dey, Brian Leyland-Jones. Targeting the PI3K-AKT-mTOR and RAF-MEK-ERK pathways in HER2 amplified breast cancer models [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P4-06-04.
Abstract P4-06-06: Growth hormone induction of oncogenic signaling promotes survival of endocrine resistant breast cancer cells
Authors: Beckwith Heather C , Yee Douglas
Published: May 2015

Targeting endocrine resistant breast cancer cells has been successfully accomplished by the use of mTORC1 inhibitors in combination with either aromatase inhibitors or tamoxifen. While there was preclinical data suggesting that targeting of the type I IGF receptor (IGF1R) might also be a target for endocrine resistant cells, clinical trials using IGF1R monoclonal antibodies showed no advantage and even suggested potential harm for the combination. IGF1R inhibition results in the disruption of an endocrine feedback loop and results in elevation of the pituitary growth factor growth hormone (GH). GH is involved in normal human growth, development, metabolism, and longevity. Growth hormone released from the pituitary stimulates production of IGF-I from the liver. The GH/IGF-1 axis is known to promote mammary gland hyperplasia and breast cancer carcinogenesis. Previous studies have shown that GH promotes carcinogenesis independently of insulin-like growth factor. The role of GH in specific subtypes of breast carcinoma remains to be defined. Our laboratory has found that estrogen receptor positive breast cancer cell lines up regulated oncogenic STAT5, Akt, and MAPK signaling pathways in response to GH. Tamoxifen resistant (TamR) and long-term estrogen deprived (LTED) breast cancer cell lines derived from MCF-7 and T47D cells demonstrated increased oncogenic signaling in response to GH compared to the corresponding parental cell lines from which they were derived. In contrast, GH stimulation of a triple negative breast cancer cell line (MDA-MB-231) failed to induce signaling via these oncogenic pathways. Although GH treatment of parental, TamR, and LTED breast cancer cells had minimal effect on cell proliferation, cell cycle progression, or migration; GH signaling protected cells from cytotoxic chemotherapy induced apoptosis. This data shows that GH signaling is found in endocrine sensitive and resistant cells. Furthermore, GH may function in protecting cells from cell death induced by either endocrine or cytotoxic drugs. GH receptor blockade may be a valid treatment option for endocrine resistant breast cancer.

Citation Format: Heather C Beckwith, Douglas Yee. Growth hormone induction of oncogenic signaling promotes survival of endocrine resistant breast cancer cells [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P4-06-06.
Abstract P4-06-07: Expression of growth hormone releasing hormone receptor ( GHRH-R ) in primary and metastatic mammary carcinomas
Authors: Nadji Mehrad , Block Norman L , Shally Andrew V , Lara Jonathan , Michaelson Rick , Ali Suhail M , Leitzel Kim , Rizvi Syed M , Al-Marrawi Mhd Yaser , Lipton Allan
Published: May 2015

In addition to its nominative function as a neurohormone acting on the pituitary, Growth Hormone Releasing Hormone (GHRH) has been shown to modify the growth behavior of numerous cancers, including breast. GHRH is produced by tumor cells, acts in an autocrine/paracrine manner, and requires the presence of GHRH receptor (GHRH-R) on the tumor cells to exert its effects. As this work has been done predominantly on tumor cell lines and xenografts, we set out to examine the clinical analog.

Matched primary and metachronous metastases from 50 breast cancers were included in this study of GHRH-R in breast cancer. Immunohistochemistry for GHRH-R (AbCam) was performed on paraffin sections and the staining results were assessed semi quantitatively from 0 (negative) to 3+ (strongly positive). A section from normal pituitary was used as positive control. Forty-three of the primary breast cancers (86%) that ultimately relapsed or metastasized showed moderate to strong immunohistochemical expression of GHRH-R. Tumors from the metastatic foci also showed strong immunoreactivity in 78%, 71%, and 44% of liver, brain, and bone foci, respectively. The lower intensity of staining in bone samples may be due to the effect of the decalcification process routinely performed before staining. Whenever present, the non-neoplastic glands adjacent to breast tumors showed either negative or 1+ reaction for GHRH-R. We conclude that the great majority of mammary carcinomas at primary and metastatic sites express GHRH-R. This finding could potentially serve as a basis for therapeutic approaches using peptide receptor antagonists. By receptor blockade using GHRH receptor antagonists, with minimal pharmacologic side-effects, we have been able to control the growth in a number of tumor cell lines (HCC1806, MDAMB468, MDAMB435S, MCF7, T47D, HCC1937, BT474, and MX1s). Based on the presence of GHRH receptors in these clinical tumors, we conclude that clinical trials evaluating GHRH receptor antagonists are indicated.

Citation Format: Mehrad Nadji, Norman L Block, Andrew V Shally, Jonathan Lara, Rick Michaelson, Suhail M Ali, Kim Leitzel, Syed M Rizvi, Mhd Yaser Al-Marrawi, Allan Lipton. Expression of growth hormone releasing hormone receptor ( GHRH-R ) in primary and metastatic mammary carcinomas [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P4-06-07.
Abstract P4-07-04: Immunohistochemical determination of arylamine N-acetyltransferase 1 (NAT1) as the target of miR-1290 and prognostic biomarker of breast cancer
Authors: Endo Yumi , Yamashita Hiroko , Takahashi Satoru , Sato Shinya , Yoshimoto Nobuyasu , Asano Tomoko , Hato Yukari , Yamaguchi Mina , Dong Yu , Toyama Tatsuya
Published: May 2015

Introduction: There are large-scale molecular differences between estrogen receptor α (ERα)-positive breast cancer and ER-negative breast cancers. In ERα-positive breast cancer, recent analyses have shown that ERα-positives can be divided into two subtypes such as luminal A and luminal B. These subtypes differ in characteristics such as response to endocrine therapy and chemotherapy, and prognosis. In a previous study, we identified a microRNA, miR-1290, that was significantly down-regulated in luminal A tumors and its potential target arylamine N-acetyltransferase 1 (NAT1). The aim of this study was to clarify whether NAT1 is a bona fide target of miR-1290, and to investigate the impact of NAT1 on breast cancer prognosis. Methods: Luciferase reporter assay was employed to validate NAT1 as a putative miR-1290 target gene. Protein expressions of NAT1, ERα, progesterone receptor (PgR) and HER2 were analyzed in 394 breast cancer samples by immunohistochemistry. Results: NAT1 was shown to be a direct target of miR-1290 by luciferase reporter assay. Expression levels of NAT1 were positively correlated with expression levels of ERα (P < 0.0001) and PgR (P < 0.0001), whereas expression levels of NAT1 were negatively correlated with both tumor grade and tumor size (P < 0.0001). Kaplan-Meier analysis showed that NAT1 presence was significantly associated with increased overall survival (OS) (P = 0.0416) in breast cancer patients (n=394). Similarly, significant associations of NAT1 presence were shown with disease-free survival (DFS) (P = 0.0048) and OS (P = 0.0055) in patients who received adjuvant endocrine therapy with tamoxifen (n = 176). Moreover, NAT1 presence was also significantly associated with increased DFS (P = 0.0025) and OS (P = 0.0007) in lymph node-positive breast cancer patients (n=147). Univariate and multivariate analyses showed significant associations between expression levels of NAT1 and DFS (P = 0.0005 and 0.019, respectively). Conclusion: We reported that miR-1290 directly targets NAT1 3’-UTR and NAT1 protein expression is correlated with improved OS of breast cancer. Moreover, NAT1 is a possible prognostic biomarker for lymph node-positive breast cancer. Thus, miR-1290 and its potential target NAT1 are associated with characteristics of breast cancer.

Citation Format: Yumi Endo, Hiroko Yamashita, Satoru Takahashi, Shinya Sato, Nobuyasu Yoshimoto, Tomoko Asano, Yukari Hato, Mina Yamaguchi, Yu Dong, Tatsuya Toyama. Immunohistochemical determination of arylamine N-acetyltransferase 1 (NAT1) as the target of miR-1290 and prognostic biomarker of breast cancer [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P4-07-04.
Abstract P4-11-25: Reappraisal of conventional risk stratification for local recurrence based on clinical outcomes in 285 resected phyllodes tumors of the breast
Authors: Yom Cha Kyong , Han Wonshik , Kim Sung-Won , Park So Yeon , Park In-Ae , Noh Dong-Young
Published: May 2015

Background A second resection has been recommended, to ensure a surgical margin of ≥ 1cm for the effective treatment of PTB, but the outcomes of an extensive series of cases casts this clinical approach in doubt.

Objective To identify the local recurrence risk factors of phyllodes tumor of the breast (PTB) and determine future optimal surgical treatment according to verified risks.

Methods All cases given a diagnosis of PTB and resected between 1989 and 2008 were retrospectively evaluated. Clinicopathologic data and clinical outcomes were analyzed and stratified according to the risks for local recurrence (LR).

Results All 285 cases occurred and 200 (70.2%) categorized as benign, 51 (17.9%) as borderline, and 34 (11.9) as malignant. Median follow-up was 6.7 years and during follow-up, there were 20 LRs. All benign PTBs recurred as benign PTB lesions. Mitosis (p = 0.007) and tumor size (p = 0.029) were independent prognostic factors for LR in multivariate analysis. Neither margin status (p = 0.773) nor type of surgery (p = 0.922) had any significance for LR.

[table 1] Local relapse-free survival by Cox-regressionSubgroup of patientsNo recurrence(%)Recurrence(%)UnivariateMultivariateHRpHRpMitosis0.0250.0071∼4/10HPF170(96.0)7(4.0)5∼9/10HPF33(84.6)6(15.4)4.2590.0094.2970.014≥10/10HPF15(88.2)2(11.8)3.4610.12212.2110.007Size0.0350.029≤2cm75(98.7)1(1.3)2cm< and ≤5cm136(89.5)16(10.5)8.5990.0375.6300.010>5cm51(98.1)1(1.9)1.5640.7520.3600.519Operation0.9570.922WLE229(93.1)17(6.9)VABS23(92.0)2(8.0)1.2470.7691.3960.814Mastectomy13(92.9)1(7.1)1.0550.9591.4720.744Margin0.8460.773Clear200(93.5)14(6.5)Close/Involvement39(92.9)3(7.1)1.1321.253

In the risk stratification for LR, PTBs sized 2 - 5cm with ≥ 10 mitoses / 10 HPF had the highest LR rate (60%) compared with all other groups (p < 0.001).

Conclusions Only PTB with 2 - 5 cm and frequent mitoses, is it recommended to follow to ascertain a wide excision and clear margin of 1 cm, it necessary by means of a 2nd surgery could be considered to avoid the risk of LR in this distinct group.

Citation Format: Cha Kyong Yom, Wonshik Han, Sung-Won Kim, So Yeon Park, In-Ae Park, Dong-Young Noh. Reappraisal of conventional risk stratification for local recurrence based on clinical outcomes in 285 resected phyllodes tumors of the breast [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P4-11-25.
Abstract P4-11-27: Prospective comparison of conventional clinicopathological factors, uPA/PAI-1 and EndoPredict®-clin score (EPclin) for adjuvant clinical decision making in ER-positive, HER2-negative breast cancer: Progesterone receptor expression is strongly associat
Authors: Ettl Johannes , Große Lackmann Kirsten , Hapfelmeier Alexander , Klein Evelyn , Paepke Stefan , Petry Christoph , Specht Katja , Wolff Laura , Höfler Heinz , Kiechle Marion
Published: May 2015

Background: Recently, EPclin, a second generation multigene test has been introduced into clinical practice. Aim of this prospective study is to compare conventional clinicopathological factors, uPA/PAI-1 and EPclin and to determine, how these parameters influence adjuvant treatment decisions. Methods: 217 consecutive cases of ER-pos, HER2neg, breast cancer cases were enrolled in this study. Conventional clinicopathological factors, uPA/PAI-1 and EPclin were obtained by central pathology assessment of the patients' surgical specimen. Decision for type of adjuvant treatment was made twice – once with and once without EPclin result- after case discussion in an interdisciplinary tumor conference. Results: 217 Patients (pt) have been evaluated. Tumor grading within the presented cohort was as follows: G1: 44 pt (20%), G2: 146 pt (68%), G3: 27 pt (12%). 59 pt (27%) had positive axillary lymph node involvement. 57 pt (26%) were pT1a/b. EPclin could be assessed in all patients. 85 pt (39%) were classified as "high risk" whereas 132 pt (61%) were classified as "low risk". uPA/PAI was obtained from 123 pt (57%). 64 pt (52%) out of these had high uPA/PAI-1 levels whereas 59 pt (48%) showed low uPA/PAI-1 levels. Level of progesterone receptor (PR) expression was obtained from 216 pt. 39 pt (18%) had low or absent PR expression (PR ≤ 20%). 26 pt (67%) of this low PR expression group were classified as EPclin high risk. Furthermore 118 pt (67%) of the high PR expression group (177 pt) were classified as "low risk" via EPclin (p<0,0001). In 89 cases (41%) treatment decision was influenced by EPclin: In 73pt (34%) adjuvant chemotherapy (ctx) was omitted whereas in 16 pt (7%) ctx was added following the EPclin result. Conclusions: This prospective study shows for the first time, that PR expression is strongly associated with risk score evaluated by EPclin testing. In comparison with uPA/PAI-1 and conventional clinicopathological factors EPclin is the more powerful tool to help reduce unnecessary adjuvant chemotherapy.

Citation Format: Johannes Ettl, Kirsten Große Lackmann, Alexander Hapfelmeier, Evelyn Klein, Stefan Paepke, Christoph Petry, Katja Specht, Laura Wolff, Heinz Höfler, Marion Kiechle. Prospective comparison of conventional clinicopathological factors, uPA/PAI-1 and EndoPredict®-clin score (EPclin) for adjuvant clinical decision making in ER-positive, HER2-negative breast cancer: Progesterone receptor expression is strongly associat [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P4-11-27.
Abstract P4-11-36: Prognostic models in male breast cancer
Authors: vanderPol Carmen C , Lacle Miangela M , Witkamp Arjen J , Kornegoor Robert , Hui Miao , Bouchardy Christine , vanderWall Elsken , Verkooijen Helena M , vanDiest Paul J
Published: May 2015

Male breast cancer (MBC) is a rare disease and its treatment is largely extrapolated from its female counterpart.

Accurate prognostication is essential for advising on adjuvant systemic treatment and informing patients. Several predictive models are available for female breast cancer (FBC) including, subsequently, the Morphometric Prognostic Index (MPI), Nottingham Prognostic Index (NPI), Adjuvant! and Predict. The aim of this study was therefore to compare the prognostic performance of these models in a group of 166 early MBC patients.

The MPI describes a "good"- (MPI<0,60) and a "poor" prognostic group (MPI>=0,60) by using a formula with mitotic activity index, tumour size and lymph node status. The NPI is calculated by a formula including size, number of lymph nodes with metastases and tumour grade and divides patients into three groups; "good-" (NPI <= 3,4), "intermediate-" (3,4=5,4) and "poor" prognosis (NPI>5,4). For the programs Adjuvant!Online and Predict, similar groups with "good"-, "intermediate"- and "poor" prognosis were defined by using tertiles. The prognostic performance of each test was studied by using the logrank-test and comparison between the models was done by using C-statistics.

The mean age was 66,4 years old and the median survival was 4,6 years with a mean of 5,8 years overall survival.

Survival of the highest predicted group was higher (MPI: 87%, NPI: 90%, Adjuvant!Online: 91% and Predict: 88%) than for the moderate groups (NPI: 76%, Adjuvant!Online: 77% and Predict: 75%) and lowest for the poor predicted groups (MPI: 51%, NPI: 43%, Adjuvant!Online: 45% and Predict: 42%), with p-values that were highly statistically significant.

In terms of discrimination, all models were moderately able to discriminate between good and poor survivors (C-statistics; MPI; 0,674, NPI; 0,678, Adjuvant!Online; 0,717 and Predict; 0,711).

In conclusion, the MPI, NPI, Adjuvant! and Predict, prognostic models that were originally developed and validated for FBC, perform fairly well for MBC. These models may therefore help in MBC prognostication and decisions on adjuvant systemic therapy.

Citation Format: Carmen C vanderPol, Miangela M Lacle, Arjen J Witkamp, Robert Kornegoor, Miao Hui, Christine Bouchardy, Elsken vanderWall, Helena M Verkooijen, Paul J vanDiest. Prognostic models in male breast cancer [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P4-11-36.
Abstract P4-12-01: Characterizing the clinical presentation of individuals with pathogenic variants in a breast/ovarian cancer gene panel
Authors: Vaccari Erica , Yackowski Lauren , Hussong Melanie , Murphy Patricia , Cremona Maria L , Booker Jessica , Hruska Kathleen
Published: May 2015

Background: Hereditary breast and ovarian cancer (HBOC) is a common indication for referral to cancer genetic counselors. Next generation sequencing panels allow for the efficient evaluation of many genes associated with increased risk of these cancers. The purpose of this study is to compare clinical histories of those with pathogenic variants in high risk versus low/moderate risk genes in order to determine which patients might benefit from more extensive testing by a panel approach.

Methods: We queried the results of patients tested at GeneDx for a panel of 21 genes causing increased breast and/or ovarian cancer risk. Data regarding personal and family history of cancer provided on the test requisition forms were analyzed and classified according NCCN guidelines for testing criteria for HBOC syndrome.

Results: Of 1709 individuals referred for testing, 146 (8.5%) tested positive for a pathogenic variant. Of these, 33% percent were found to carry a pathogenic BRCA1/2 variant while 67% tested positive for a pathogenic variant in a gene other than BRCA1/2 (CHEK2: 17%; ATM: 12%; PALB2: 10%; BRIP1: 7%; BARD1: 3%; PTEN: 3%; each of FANCC, MSH2, MSH6, NBN, PMS2, RAD51C, RAD51D: 2%; MLH1: 1%). Eighty-six percent of these individuals were affected with cancer. In the probands with a pathogenic BRCA1/2 variant, 66% were diagnosed with breast cancer and 22% with ovarian cancer compared to the probands with a pathogenic variant in a gene other than BRCA1/2 of whom 84% had a history of breast cancer and 17% had ovarian cancer. The highest number of breast cancer diagnoses were found, in decreasing order, in association with pathogenic variants in BRCA1 (20), CHEK2 (20), ATM (17), PALB2 (14), BRCA2 (13), and BRIP1 (12). The greatest number of ovarian cancers were identified, in decreasing order, in association with pathogenic variants in BRCA2 (8), BRCA1 (3), CHEK2 (3), and ATM (3). Furthermore, all of the individuals with pathogenic variants met NCCN guidelines for HBOC.

Conclusion: A high yield of pathogenic variants were found in genes other than BRCA1/2. Data analysis also shows that individuals with a pathogenic variant in genes other than BRCA1/2 did not have a notably less severe clinical history than those pathogenic variants in BRCA1/2. As all individuals tested meet NCCN guidelines for HBOC testing, panel testing should be considered in this population.

Citation Format: Erica Vaccari, Lauren Yackowski, Melanie Hussong, Patricia Murphy, Maria L Cremona, Jessica Booker, Kathleen Hruska. Characterizing the clinical presentation of individuals with pathogenic variants in a breast/ovarian cancer gene panel [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P4-12-01.
Abstract P4-15-17: A novel targeted engineered toxin body for treatment of HER2 positive breast cancer
Authors: Willert Erin K , Rajagopalan Sangeetha , Robinson Garrett L , Brieschke Brigitte , Erdman Jennifer , Null William , Higgins Jack P
Published: May 2015

The HER2 receptor is overexpressed in 20-30% of breast cancers. HER2 overexpression in breast cancer has been successfully targeted by both antibody and antibody-drug conjugate (ADC) approaches. The recently approved trastuzumab-emtansine (T-DM1, Kadcyla) ADC has shown promising clinical results in patients refractory to trastuzumab (Herceptin). Because DM1 is a chemotherapeutic and refractory breast cancer patients have typically progressed through several rounds of chemotherapy, we are developing a new targeted therapy approach utilizing a novel mechanism of action. MT-2H74 is an engineered toxin body comprised of the trastuzumab single chain variable fragment (scFv) and a modified ribosome-inactivating protein derived from Shiga-like toxin 1 A (SLT-1A). We have proprietarily modified SLT-1A for reduced immunogenic potential and increased stability. MT-2H74 selectively binds HER2-expressing breast cancer cells, and exerts a potent HER2-specific cytotoxic effect on several tested cell lines. MT-2H74 demonstrates effective cell kill at picomolar concentrations on cell lines expressing high levels of HER2 and is not cytotoxic to HER2 negative control cell lines. Multi-drug resistance transporter 1 (MDR1) has been reported to confer resistance to chemotherapeutic and ADC treatments, such as direct T-DM1 cell kill; however, MT-2H74 displays cytotoxic activity against HER2 transfected NCI/ADR-RES cells known to express MDR1. Murine models are under investigation to determine therapeutic efficacy in vivo. MT-2H74 is a promising HER2-targeted therapeutic agent against breast carcinomas with a unique mechanism of action and is currently under further development.

Citation Format: Erin K Willert, Sangeetha Rajagopalan, Garrett L Robinson, Brigitte Brieschke, Jennifer Erdman, William Null, Jack P Higgins. A novel targeted engineered toxin body for treatment of HER2 positive breast cancer [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P4-15-17.
Abstract P5-04-12: Targeting of phosphatidylserine by monoclonal antibodies enhances activity of immune checkpoint inhibitors in breast tumors
Authors: Freimark Bruce , Gong Jian , Nguyen Van , Yin Shen , Archer Rich , Hutchins Jeff
Published: May 2015

Phosphatidylserine (PS) is a phospholipid normally residing in the inner leaflet of the plasma membrane and becomes exposed on tumor vascular endothelial cells (ECs) and tumor cells. PS exposure becomes enhanced in response to chemotherapy, irradiation, and oxidative stresses in the tumor microenvironment. PS exposure in tumors promotes an immunosuppressive microenvironment which includes the recruitment of myeloid derived suppressor cells (MDSCs), immature dendritic cells, and M2-like macrophages as well as the production of anti-inflammatory cytokines. Binding of PS targeting antibodies on tumor endothelial cells, tumor cells and their secreted microparticles triggers an Fc-FcR mediated pro-inflammatory cellular and cytokine response that reverses the immunosuppressive PS meditated checkpoint, thereby enhancing anti-tumor immunity. A chimeric PS-targeting antibody, bavituximab, is being used in combination with chemotherapy to treat patients with solid tumors in multiple late-stage clinical trials. Using breast tumors in immune competent mice, we demonstrate PS targeting antibodies enhance the anti-tumor activity of anti-CTLA-4 and anti-PD-1 antibodies in the presence and absence of conventional chemotharapy. Tumor growth inhibition correlates with infiltration of immune cells in tumors and induction of adaptive immunity. The combination of these mechanisms promotes strong, localized, anti-tumor responses without the side-effects of systemic immune activation.

Citation Format: Bruce Freimark, Jian Gong, Van Nguyen, Shen Yin, Rich Archer, Jeff Hutchins. Targeting of phosphatidylserine by monoclonal antibodies enhances activity of immune checkpoint inhibitors in breast tumors [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P5-04-12.
Abstract P5-05-11: Growth hormone receptor silencing sensitizes triple negative breast cancer cells to chemotherapy
Authors: Arumugam Arunkumar , Subramani Ramadevi , Nandy Sushmita , Lopez-Valdez Rebecca , Lakshmanaswamy Rajkumar
Published: May 2015

Triple negative breast cancer (TNBC) is an aggressive form of breast cancer, which, accounts for approximately, 15% of breast cancers diagnosed in women. TNBCs lack expression of estrogen receptor, progesterone receptor and human epidermal growth factor receptor type 2 (HER2). So, there are no targeted therapies available for TNBCs and chemotherapy is the main choice for the treatment. Although the tumors respond initially, large numbers of patients develop recurrence due to chemoresistance. Growth hormone receptor (GHR) is a class I cytokine receptor, which plays vital role in the development of chemoresistance. Studies have shown that silencing of GHR sensitizes breast cancer cells to chemotherapeutic drugs. In this study we investigated the impact of GHR silencing in TNBC cells and further analyzed the possible mechanisms associated with GHR silencing induced sensitization. GHR was silenced using small interfering RNAs in metastatic breast cancer cells MDA MB 231 and MDA MB 468. Molecular analyses were performed to determine apoptosis, cytotoxicity, colony formation, invasion and migration in GHR knockdown cells. Silencing of GHR induced cytotoxicity and apoptosis in TNBC cells. Migratory and invasive potentials were drastically reduced in GHR silenced cells. Moreover, epithelial to mesenchymal transition markers were significantly down regulated by GHR siRNA treatment. GHR targeting significantly increased the efficiency of docetaxel against TNBC cells. Inhibition of GHR also inhibited the expression of BCRP, which is frequently associated with the development of chemoresistance in breast cancer. Further, treatment with GH induced the overexpression of drug transporter proteins involved in chemoresistance. Inhibition of GHR in breast cancer cells reverted the expression of these proteins and sensitized the cells to docetaxel. These findings support the hypothesis that targeting GHR could have a potential new therapeutic approach to overcome chemoresistance in TNBCs.

Citation Format: Arunkumar Arumugam, Ramadevi Subramani, Sushmita Nandy, Rebecca Lopez-Valdez, Rajkumar Lakshmanaswamy. Growth hormone receptor silencing sensitizes triple negative breast cancer cells to chemotherapy [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P5-05-11.
Abstract P5-05-13: Obesity confers chemotherapy resistance in triple negative breast cancer cells
Authors: Lehrmann Victoria R , Bowers Laura W , Brenner Andrew J , deGraffenried Linda A
Published: May 2015

Introduction: Obesity is associated with a more aggressive breast cancer and a worse outcome following chemotherapy treatment. Triple negative breast cancer is a highly aggressive subtype of breast cancer characterized by the absence of estrogen, progesterone, and human epidermal growth factor-2 (HER2) receptors. This subtype has also been correlated with a worse prognosis. This study aims to investigate the impact of obesity on triple negative breast cancer cells’ response to chemotherapy treatment and elucidate potential therapeutic options to improve response.

Methods: Sera was collected from breast cancer patients at the Cancer Therapy and Research Center at The University of Texas Health Science Center at San Antonio (UTHSCSA) and pooled according to body mass index (BMI) category (Control:18.5 to 24.9 kg/m2; Obese:≥30 kg/m2). MDA-MB-231 cells, a triple negative breast cancer cell line, were grown in serum-free media supplemented with 2% obese or control patient sera to create an in vitro model of obesity. The effects of docetaxel, a chemotherapeutic agent, on cell viability in the presence of obese versus control sera were examined by MTT. Modulation of B-cell lymphoma 2 (Bcl-2), cyclooxygenase-2 (COX-2), and mammalian target of rapamycin (mTOR) were evaluated as possible mechanisms for obesity-induced chemotherapy resistance.

Results: The obese sera significantly reduced sensitivity of the MDA-MB-231 cells to docetaxel. In fact, there was no variance in the viability level of cells grown in obese patient sera for 96 hours with and without docetaxel treatment. The mechanism for resistance does not appear to involve Bcl-2 or COX-2, previously implicated in docetaxel resistance. Intriguingly, suppression of mTOR did provide significant benefit, in agreement with our previous in vivo studies investigating obesity and aromatase inhibitor (AI) response. The role of the mTOR pathway in modulating therapeutic response is still being investigated.

Conclusion: Exposure to obesity-associated circulating factors confers chemotherapy resistance in triple negative breast cancer cells. Further research will be conducted to determine the mechanism by which obesity promotes chemotherapy resistance and whether modulation of the mTOR pathway will provide significant benefit.

Citation Format: Victoria R Lehrmann, Laura W Bowers, Andrew J Brenner, Linda A deGraffenried. Obesity confers chemotherapy resistance in triple negative breast cancer cells [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P5-05-13.
Abstract P5-15-12: Clinico-biological characteristics of patients surviving more than two years with metastatic breast cancer (MBC): Results of a transversal national multicentric survey
Authors: Loirat Delphine , Tlemsani Camille , Arrondeau Jennifer , Bellesoeur Audrey , Le Tourneau Christophe , Rousseau Benoit
Published: May 2015

Introduction:

MBC cancer patients may have prolonged survival, and MBC cancers can be considered as a chronic disease. The main goal of the present study was to describe the clinico-biological features of patients surviving more than two years with MBC.

Method: During 4 months, we conducted a national multicentric survey about patients aged ≥ 18 in metastatic setting (all solid tumors) for more than 24 months. Clinico-biological data from 200 patients were collected in 39 French centers. Preliminary results of MBC patients (N=88, 87 women/one man) are presented.

Results: Most of them were ductal carcinoma (88%), expressing hormonal receptor HR (77%). 43% of tumors overexpressed HER2 (HER2+ tumors: 43%; Triple negative tumors: 6%). Median age at MBC diagnosis was 53 years [29-85]. 18% had metastatic disease at diagnosis and 82 % were localized with a disease-free survival of 65 months [4-312]. Median time of MBC disease was 4,5 years [2-20]. At the time of MBC diagnosis, 64% of patients were not single; 55% were working while 30% were retired. At data collection, 89% of non-single patients were not separated, and 43 % of working patients at diagnosis were still working.

Mean number of treatment lines in advanced disease was 4.7 [1-13]. 89% of MBC patients received at least one chemotherapy, 68% hormonotherapy, 70% targeted therapy and 38% had been included in at least one clinical trial. 97% of patients had a local treatment of their primary tumor. Concerning metastasis, 23% had a surgical treatment and 40% radiotherapy treatment. 80% of patients remain with PS of 0 or 1. Only 9% of patients were followed by a palliative care team, 24% by a psychologist and 23% by a nutritionist.

Conclusion: Our preliminary results of suggest that an important proportion of MBC cancer patients who live more than 2 years are young, have been treated with chemotherapy, hormonal and targeted therapy, have participated to clinical trials and still have good performance status. No change in marital status was observed. Half of working patients at MBC diagnosis continue to work. Few of them received palliative care. This study may help to better describe long-term survivors with MBC, and socio-medical burden as cancer became a chronic disease.

Citation Format: Delphine Loirat, Camille Tlemsani, Jennifer Arrondeau, Audrey Bellesoeur, Christophe Le Tourneau, Benoit Rousseau. Clinico-biological characteristics of patients surviving more than two years with metastatic breast cancer (MBC): Results of a transversal national multicentric survey [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P5-15-12.
Abstract P6-02-05: Systemic statin treatment and intra-tumoral lipid metabolism - report from a window-of-opportunity breast cancer trial
Authors: Feldt Maria , Menard Julien , Belting Mattias , Borgquist Signe
Published: May 2015

Background:

In recent years, attention has been drawn to the plasma cholesterol lowering drugs statins (HMGCR-inhibitors) due to their exertion of pleiotropic intratumoral effects such as induction of apoptosis and inhibition of proliferation, generating a possible utility in cancer prevention and treatment. However, the molecular mechanisms are complex and remain largely undefined. The aim of this study was to assess the statin induced changes of the intra-tumoral levels of cholesterol, to gain enhanced understanding of the role of the mevalonate pathway in cancer lipid metabolism.

Methods:

The study was designed as a window-of-opportunity trial, where 50 patients with primary invasive breast cancer were included, and treated with 80 mg of atorvastatin/day for two weeks, between the time of diagnosis and surgery. From frozen tumor tissue samples pre- and post atorvastatin treatment, lipids have been extracted, and the cholesterol levels have been measured using a cholesterol quantification assay. In vitro experiments on MCF7-cells treated with atorvastatin was used for optimization and comparison on the cellular level.

Results:

42 patients completed all study parts, and assessment of the cholesterol levels in the paired frozen tumor tissue was achievable in 14 pairs. Following atorvastatin treatment, the intra-tumoral levels of total cholesterol was significantly increased (P=0.035), with an increase in 11 of the pairs, and decrease in 3 pairs. Similar findings were observed in the in vitro experiments, demonstrating increased levels of total cholesterol and storage in lipid droplets in the cells treated with atorvastatin.

Conclusions:

We have earlier reported statin-induced anti-proliferative effects in breast cancer. This study shows a statin-induced increase in the intra-tumoral cholesterol levels, which may however rely on the increased cholesterol storage in lipid droplets, a phenomenon observed in the in vitro experiments with MCF7 cells treated with atorvastatin. Our results suggest that the anti-proliferative effects exerted by statins reluctantly reduce cell metabolism and consequently increase the storage of e.g. lipids.

Citation Format: Maria Feldt, Julien Menard, Mattias Belting, Signe Borgquist. Systemic statin treatment and intra-tumoral lipid metabolism - report from a window-of-opportunity breast cancer trial [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P6-02-05.
Abstract P6-02-09: Structure-activity relationship of ruthenium (Ru) complexes to inhibit breast cancer growth and metastasis
Authors: Iida Joji , Prazo Marc L , Lu Yifeng , Bell-Loncella Elisabeth T , Shriver Craig D
Published: May 2015

Previous studies demonstrated that transition metal complexes inhibit cancer cell growth. We have examined a series of ruthenium (Ru (II)) complexes for their ability to inhibit growth of breast cancer cells. Among three complexes with the general formula [Ru(η6-p-cym)(N-N)Cl]+ tested for their abilities to inhibit MDA-MB-231 cell growth, the complex with o-phenalyenediamine (o-pda) as the bidentate nitrogen donor (N-N) ligand, [Ru(η6-p-cym)(o-pda)Cl]+, showed significant inhibitory activity in both a concentration- and a time-dependent manners. Although [Ru(η6-p-cym)(o-pda)Cl]+ inhibited growth of various human cancer types such as MCF-7 (breast), SK-Br3 (breast), B-cell lymphoma (Raji), osteosarcoma (HT1080), and melanoma (Bowes) cells, two TN breast cancer cells, HCC1806 and HCC38, were resistant to this treatment, suggesting cell-type specific functions of [Ru(η6-p-cym)(o-pda)Cl]+ for inhibiting cell growth. When MDA-MB-231 cells were treated with [Ru(η6-p-cym)(o-pda)Cl]+, both cleavage of caspase-3 and release of HMGB-1 into conditioned medium increased in a concentration dependent manner, suggesting [Ru(η6-p-cym)(o-pda)Cl]+ induced both apoptosis and necrosis processes. Importantly, [Ru(η6-p-cym)(o-pda)Cl]+ synergistically inhibited MDA-MB-231 cell growth with cyclophosphamide but not doxorubicin and paclitaxel. These results suggest that [Ru(η6-p-cym)(o-pda)Cl]+ is a potent tumor growth inhibitor per se and enhances tumoricidal activity of chemotherapeutic agents such as cyclophosphamide. Thus, Ru (II) complexes are promising anti-cancer drugs which could be used alone and/or in combination with chemotherapeutic agents for breast cancer patients. The opinion and assertions contained herein are the private views of the authors and are not to be construed as official or as representing the views of the Department of the Army or the Department of Defense.

Citation Format: Joji Iida, Marc L Prazo, Yifeng Lu, Elisabeth T Bell-Loncella, Craig D Shriver. Structure-activity relationship of ruthenium (Ru) complexes to inhibit breast cancer growth and metastasis [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P6-02-09.
Abstract P6-05-02: Expression of ING1b-derived peptide inhibits viability of breast cancer cells and promotes apoptosis
Authors: Boyko Oleksandr , Riabowol Karl
Published: May 2015

The ING1b protein is a type II tumor suppressor and a stoichiometric member of HDAC-containing protein complexes. Primarily by altering chromatin structure, ING1b contributes to regulation of gene expression, senescence and apoptosis. Mislocalization and decreased levels of ING1b are commonly observed in human tumors and cancer cell lines. Multiple independent studies in varied cell types report that ING1b overexpression promotes apoptosis. Since the inactivation of apoptosis pathways is frequent in cancer cells, modulating ING1b expression in tumors may serve as a viable approach for cancer therapy. We have defined the minimal ING1b region that confers apoptotic function as estimated by the levels of PARP cleavage, FACS analysis and using an Annexin V binding assay. We have established that ING1b-derived peptides containing its third alpha helix (A3H) and NLS/NTS domains are able to induce apoptosis at levels comparable to those of full length ING1b. The A3H-NLS/NTS peptide exhibited strong nucleolar localization characteristic of full length ING1b. Cells overexpressing the full length ING1b and A3H-NLS/NTS peptide showed similar changes in cell morphology characteristic of apoptosis and exhibited increased levels of PARP cleavage. While the A3H region that includes the N-terminal part of the highly conserved Lamin Interacting Domain (LID) was necessary but not sufficient, the NLS/NTS domain that mediates nuclear and nucleolar localization of ING1b was required and partially sufficient for induction of apoptosis. Adenoviral-mediated expression of A3H-NLS/NTS peptide in cells of osteosarcoma, glioblastoma and breast cancer origins resulted in strong reduction of cell viability. Depending on the cell line, treating cells with 45 MOI of virus expressing A3H-NLS/NTS peptide resulted in a 60 - 85% decrease in cancer cell survival compared to cells treated with the control construct (Ad-GFP), and the highly transformed triple negative tumorigenic MDA-MB-468 breast cancer line was sensitive to the peptide when infected with 5 MOI of A3H-NLS/NTS adenovirus. These pro-apoptotic effects were found to be dose and time dependent. Furthermore, using p53 wild-type, p53 mutant and p53-null cancer cell lines we demonstrated that the effects of A3H-NLS/NTS expression on cell survival and apoptosis were independent of p53-status. The evaluation of the synergy between the A3H-NLS/NTS peptide and common chemotherapeutic agents is currently ongoing. Our long-term goal is to develop ING1b-based therapeutics that can be used as an adjuvant therapy in combination with the existing breast cancer treatments.

Citation Format: Oleksandr Boyko, Karl Riabowol. Expression of ING1b-derived peptide inhibits viability of breast cancer cells and promotes apoptosis [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P6-05-02.