Genomic predictors of response to doxorubicin versus docetaxel in breast cancer
ABSTRACT: Low topo2a expression and ER-negative status were predictors of response to doxorubicin, while small tumor size and ER-negative status predicted response to docetaxel. Docetaxel was superior to doxorubicin in triple-negative/basal-like tumors, while no significant differences between these drugs were seen in the remaining intrinsic subtypes Keywords: reference x sample reference x sample
Project description:Results: In subjects who completed treatment and surgery, the pCR and near-complete response rates were 15.8% in HER2-negative and 50% in HER2-positive subjects. When stratified by genomic subtype, subjects of the HER2-enriched subtype had the best response (66.7%), the luminal A (11%) and B (4.8%) subtypes the poorest. Of 147 patients tested for p53 mutations using the AmpliChip test, 78 variants were detected; 55 were missense. The response rate among TP53 mutated patients was 30%, significantly higher than the rate in TP53 wild-type patients (10%, P = .0032). Concordance between AmpliChip mutation status versus IHC staining was 65%, with AmpliChip status being predictive of response and IHC status being not being predictive. Conclusion: Capecitabine plus docetaxel in HER2-negative subjects, and with trastuzumab in HER2-positive subjects, provided a good response rate with fewer cycles. p53 mutational analysis using the AmpliChip p53 assay, and genomic subtyping using the PAM50 assay, were promising predictive tests of response. reference x sample
Project description:The basal-like breast cancer subtype portends a poor clinical prognosis, and a defining feature of this subtype is the high expression of genes in the “proliferation signature”. B-Myb, a member of the MYB protein family of transcription factors, is highly expressed in the proliferation signature and is amplified and overexpressed in a variety of tumor types, including breast. In this report we demonstrated that B-Myb is highly expressed in basal-like breast cancer relative to the other subtypes, and B-Myb expression alone is prognostic. We also identified an association between a nonsynonymous B-Myb germline variant (S427G, rs2070235) and an increased risk of having a basal-like breast cancer among patients with breast cancer. The expression of B-Myb, or the S427G variant, was manipulated in vitro and we observed that in hTERT-immortalized normal Human Mammary Epithelial Cells, but not basal-like tumor-derived lines, cells ectopically expressing B-Myb showed increased sensitivity to DNA topoisomerase II inhibitors, but not other chemotherapeutics; in addition, microarray analyses of B-Myb overexpressing cells identified many G2/M targets as being preferentially induced. These results again suggest that B-Myb is involved in G2/M cell cycle control and that dysregulation of B-Myb may contribute to an increased sensitivity to a specific class of chemotherapeutic agents in vitro, and potentially in vivo. These data provide insight into the influence of B-Myb in human breast cancer, which is of potential clinical importance for determining disease risk and for guiding treatment. Experiment Overall Design: Reference VS. Samples
Project description:Cancer progression is mediated by processes that are also important in wound repair. As a result, cancers have been conceptualized as overhealing wounds or "wounds that do not heal," and gene expression signatures reflective of wound repair have shown value as predictors of breast cancer survival. Despite the widespread acknowledgment of commonalities between host responses to wounds and host responses to cancer, the gene expression responses of normal tissue adjacent to cancers have not been well characterized. Using RNA extracted from histologically normal breast tissue from 105 patients, 121 arrays were performed, including 72 arrays representing 58 reduction mammoplasty patients and 49 arrays representing 47 cancer patients, we measured whole genome expression profiles and identified a gene expression signature that is induced in response to breast cancer.
Project description:Microarray data to accompany Gauger et al. (2009) Cancer Cell International paper A treated X untreated design was used whereby immortalized human mammary epithelial cell lines (TERT cells) were modified to stably express an siRNA that knocked down SFRP1 expression. These "treated" cells were labeled with Cy5 and four replicate harvests were hybridized to Agilent 4by44k whole genome microarrays, along with a Cy3 labeled untreated control. The untreated control consisted of 4 pooled harvests of the parent cell line in normal growth conditions at 60-80% confluence.
Project description:Mammalian SWI/SNF-related complexes have been implicated in cancer based on some of the subunits physically interacting with RB and other proteins involved in carcinogenesis. Additionally, several subunits are mutated or not expressed in tumor-derived cell lines. Strong evidence for a role in tumorigenesis in vivo, however, has been limited to SNF5 mutations that result primarily in malignant rhabdoid tumors (MRTs) in humans and MRTs as well as other sarcomas in mice. We previously generated a null mutation of the Brg1 catalytic subunit in the mouse and reported that homozygotes die during embryogenesis. Here, we demonstrate that Brg1 heterozygotes are susceptible to mammary tumors that are fundamentally different than Snf5 tumors. First, mammary tumors are carcinomas not sarcomas. Second, Brg1+/- tumors arise because of haploinsufficiency rather than loss of heterozygosity (LOH). Third, Brg1+/- tumors exhibit genomic instability but not polyploidy based on array CGH results. We monitored Brg1+/-, Brm-/- double-mutant mice but did not observe any tumors resembling those from Snf5 mutants, indicating that the Brg1+/- and Snf5+/- tumor phenotypes do not differ simply because Brg1 has a closely related paralog whereas Snf5 does not. These findings demonstrate that BRG1 and SNF5 are not functionally equivalent but protect against cancer in different ways. We also demonstrate that Brg1+/- mammary tumors have relatively heterogeneous gene expression profiles with similarities and differences compared to other mouse models of breast cancer. The Brg1+/- expression profiles are not particularly similar to mammary tumors from Wap-T121 transgenic line where RB is perturbed. We were also unable to detect a genetic interaction between the Brg1+/- and Rb+/- tumor phenotypes. These latter findings do not support a BRG1-RB interaction in vivo. Experiment Overall Design: 14 microarrays consisting of 12 unique Brg1+/- murine mammary Experiment Overall Design: tumors
Project description:Introduction: The I-SPY 1 TRIAL was designed to evaluate complete pathologic response and tumor volume change, measured by magnetic resonance imaging (MRI), stratified by molecular subtypes and link response to 3-year recurrence free survival (RFS).Methods: Eligible patients had T =3 cm and received neoadjuvant chemotherapy with AC plus optional taxane. Serial MRI, biopsy, and blood draws were conducted over the course of treatment, and a database of multiple molecular profiles was assembled.Results: A total of 221 patients were eligible for analysis: median tumor size was 6.0 cm and median age was 49 years. The I-SPY 1 TRIAL patients had tumors with aggressive biology: 45% were estrogen receptor (ER) negative, 31% Her2+; and 91% high risk by the Netherlands Cancer Institute (NKI) 70-gene profile. After a median of 3.9 years, RFS was 77%. HR/HER2 status improved predictability of RFS with the greatest difference between HR+/HER2- and triple-negative disease (hazard ratio 0.39). Wound healing signature activation, p53 mutation, and Risk of Relapse (ROR) score were highly correlated and also significantly improved the accuracy of RFS predictions when added to stage. The rate of pathologic complete response (pCR) varied considerably from a low of 0-2% (NKI low risk, luminal A) to a high of 43-61% (17q Amplified, HER2 enriched, HR-/HER2+). Both pCR and the more refined residual cancer burden (RCB) were significant predictors of RFS for all patients and even more predictive when analyzed within biomarker subsets. Good risk (NKI low, ROR-S low risk, Wound Healing quiescent, p53 wild type) signatures were associated with significantly higher 3-year RFS than poor risk expression signatures (ROR-S high risk, Wound Healing Activated, p53 mutation, NKI high risk).Conclusion: Importantly, in this set of biologically poor prognosis tumors, pCR predicts for better outcome, especially when analyzed within breast cancer subsets. Keywords: reference x sample reference x sample
Project description:Abstract Background. Epidermal growth factor receptor (EGFR) is a targetable molecule in basal-like breast cancer, which comprises most “triple negative” breast cancer (TNBC), the only breast cancer subtype without established targeted therapy. Methods. In this randomized phase II trial, metastatic TNBC patients received the anti-EGFR antibody cetuximab (250mg/kg/week iv) with carboplatin (AUC2/wk iv) added on progression, or concomitant cetuximab + carboplatin. Molecular subtyping was done on archival specimens and those with accessible tumors provided fresh tissue, before and after 7-14 days of therapy, for microarray analyses to explore EGFR pathway inhibition. Results. Of 102 TNBC patients 74% were of the basal-like molecular subtype. Response rate to cetuximab was 6% (2/31), and was 16% (4/25) to cetuximab + carboplatin after progression. Upfront cetuximab + carboplatin produced responses in 17% (12/71); 31% responded or had prolonged disease stabilization. Time to progression was 2.1 months (95% CI 1.8-5.5) and overall survival 10.4 months (95% CI 7.7-13.1) for those treated with the combination regimen. Among 16 patients with evaluable serial biopsies, genomic patterns of the EGFR pathway showed activated status in 13 and inhibition by therapy in 5. Conclusions. While most TNBC were basal-like, a significant proportion were different subtypes. The aggressive nature of metastatic TNBC leads to limited survival. Despite a promising preclinical rationale and evidence of EGFR pathway activation in most, targeted treatment with cetuximab as a single agent had marginal activity and cetuximab added to carboplatin demonstrated modest activity. Serial biopsies as part of metastatic breast cancer studies are feasible, and this study confirmed that the EGFR pathway was inhibited by therapy in only a minority suggesting ligand-independent activation in most tumors. Tissue acquisition and drug selection based upon individualized pathway activation status should be an important part of future studies of TNBC. This series contains 36 microarrays that are from 18 patients with fresh frozen tissue available from the metastatic site. Pretreatment samples (Bx0) are available for two patients. Pretreatment and post single agent treatment (7-14 days after start of treatment with cetuximab; BxSingle) are available for three patients. Pretreatment and post combination treatment (7-14 days after start of treatment with cetuximab plus carboplatin; BxCombo) are available for eight patients. Two patients have a pretreatment sample, a sample after 7-14 days of treatment with single agent cetuximab, and a third sample 7-14 days on cetuximab plus carboplatin after switching to the combination arm upon progression on the single agent arm. Samples were hybridized with Stratagene common reference spiked with RNA from two breast cancer cell lines (ME16C and MCF-7) on Custom 1x44K Agilent microarrays. Arrays were scanned on an Axon 4000B scanner and analyzed with GenePix Pro software.
Project description:Methods: RNA-sequencing was performed on matched samples obtained across several different gene expression measurement methods including: (a) fresh-frozen (FF) RNA samples by mRNA-seq, Ribo-zero and DSN and (b) FFPE samples by Ribo-zero and DSN. We also assayed the matched samples with Agilent microarray. RNA-seq data was compared on the rRNA-removal efficiency, genome profile, library complexity, coverage uniformity and quantitative cosinstency across protocols and with microarray data. Results: Compared to mRNA-seq, Ribo-zero provides equivalent percentage of rRNA component, genome-based mapped reads, and consistent quantification of transcripts. Moreover, Ribo-zero and DSN protocols achieve concordant transcript profiling in FFPE samples, and provide substantially more information on non-poly(A) RNA, which cannot be captured by mRNA-seq. Therefore, our study provides evidence that RNA-sequencing can generate accurate and reproducible transcript quantification using FFPE tissues. mRNA profile of 11 breast tumors were assayed by Agilent microarray, and by RNA-sequencing on libraries including: (a) fresh-frozen (FF) RNA samples by mRNA-seq, Ribo-zero and DSN and (b) FFPE samples by Ribo-zero and DSN, using Illunia HiSeq2000 2x50bp. RNA-Seq raw data is to be made available through dbGaP (controlled access) due to patient privacy concerns: http://www.ncbi.nlm.nih.gov/gap/?term=phs000676
Project description:For the largest class of human tumors, those of epithelial origin, little is known about their initiating genetic hits or cells of origin. Whether tissue stem cells or more committed progenitors are targets for transformation is also uncertain. Experience in hematopoietic malignancies and sarcomas teaches that recurrent chromosomal translocations represent initiating oncogenic events. To develop a system in which epithelial tumorigenesis can be assessed from the initial event to frank malignancy, we have generated mice that conditionally express the Etv6-NTRK3 (EN) fusion oncoprotein, the product of the t(12;15)(p13;q25) translocation characteristic of one form of human breast cancer. Activation of EN expression in mammary tissues by Whey acidic protein (Wap) promoter-driven Cre leads to fully penetrant, multifocal malignant breast cancer with short latency. We provide genetic evidence that committed, bipotent or CD61+ luminal alveolar progenitors, can be targets of tumorigenesis. Furthermore, EN transforms these otherwise transient progenitors through the AP1 complex. Our model supports the existence of an epithelial cell hierarchy in both normal mammary glands and malignancy. To our knowledge, this is the first murine model of human epithelial cancer based on a recurrent chromosomal translocation. Given increasing relevance of chromosomal translocations in epithelial cancers, such mice serve as a paradigm for the study of their genetic pathogenesis and cellular origins, and generation of novel preclinical models. Experiment Overall Design: Reference X Sample
Project description:Translational breast cancer research is hampered by difficulties in obtaining and studying primary human breast tissue, and by the lack of in vivo preclinical models that reflect patient tumor biology accurately. In an effort to overcome these limitations, we propagated a cohort of human breast tumors grown in the mammary fat pad of SCID/Beige and NOD/SCID/IL2?-receptor null (NSG) two relatively new immunocompromised mouse models, under a series of transplant conditions. Both models yielded stably transplantable xenografts relatively high rates compared with previously available immunocompromised mice. Xenograft lines were established directly from breast cancer patient samples, without intervening culture in vitro, using the epithelium-free mammary fat pad as the transplantation site. Of the conditions tested, xenograft take rate was highest in the presence of a low-dose estradiol pellet. Overall, 35 stably transplantable xenograft lines representing 27 patients were established, using pre-treatment, mid-treatment, and/or post-treatment samples. Most patients yielding xenografts were “triple-negative” (ER-PR-HER2-) (n=21). However, we were able to establish lines from three ER-PR-HER2+ patients, one ER+PR-HER2-, one ER+PR+HER2- and one “triple-positive” (ER+PR+HER2+) patient. Serially passaged xenografts show biological consistency with the tumor of origin at the histopathology level, and remarkable stability across multiple transplant generations at the genomic, transcriptomic, and proteomic levels. Of the 27 patients represented, xenografts derived from 13 patients showed metastasis to the mouse lung. These models thus serve as a renewable, quality-controlled tissue resource, and should prove useful for preclinical evaluation of experimental therapeutics. reference x sample