Project description:Anti-cancer drug testing is challenging, but genetically engineered mouse models (GEMMs) and orthotopic, syngeneic transplants (OSTs) may offer advantages for pre-clinical testing including an intact microenvironment. We examined the efficacy of six chemotherapeutic or targeted anti-cancer drugs, alone and in combination, using over 500 GEMMs/OSTs representing three distinct breast cancer subtypes: Basal-like (C3(1)-T-antigen GEMM), Luminal B (MMTV-Neu GEMM), and Claudin-low (T11/TP53-/- OST). While a few single agents offered exceptional efficacy like lapatinib in the Neu/ERBB2 driven model, combination therapies tended to be more active and life prolonging. Using expression profiling of chemotherapy treated murine tumors, we identified an expression signature that was able to predict pathological complete response to neoadjuvant anthracycline-taxane treated human breast cancer patients, even after accounting for the common clinical variables and other genomic signatures. These results show that credentialed murine models can predict the efficacy of would-be anti-cancer compounds in humans, and that GEMMs can be used to develop new biomarkers of therapeutic responsiveness in humans. control X treatment
Project description:Anti-cancer drug testing is challenging, but genetically engineered mouse models (GEMMs) and orthotopic, syngeneic transplants (OSTs) may offer advantages for pre-clinical testing including an intact microenvironment. We examined the efficacy of six chemotherapeutic or targeted anti-cancer drugs, alone and in combination, using over 500 GEMMs/OSTs representing three distinct breast cancer subtypes: Basal-like (C3(1)-T-antigen GEMM), Luminal B (MMTV-Neu GEMM), and Claudin-low (T11/TP53-/- OST). While a few single agents offered exceptional efficacy like lapatinib in the Neu/ERBB2 driven model, combination therapies tended to be more active and life prolonging. Using expression profiling of chemotherapy treated murine tumors, we identified an expression signature that was able to predict pathological complete response to neoadjuvant anthracycline-taxane treated human breast cancer patients, even after accounting for the common clinical variables and other genomic signatures. These results show that credentialed murine models can predict the efficacy of would-be anti-cancer compounds in humans, and that GEMMs can be used to develop new biomarkers of therapeutic responsiveness in humans.
Project description:The initiation of drug response in neuroblastoma was assessed using this genetically engineered mouse model. scRNAseq was employed to determine the heterogeneity of the initial transcriptional response to the common chemotherapeutic drug, cisplatin.
Project description:Synovial sarcoma-like tumors were generated in mice by conditionally expressing the human t(X;18) translocation-derived SYT-SSX2 fusion protein. Using a Tamoxifen-inducible CreER system, we show here that sporadic expression of SYT-SSX2 across multiple tissue types leads to exclusive formation of synovial sarcoma-like tumors while its widespread expression is lethal. CreER-based sporadic expression both avoids the severe early developmental phenotypes associated with widespread SYT-SSX2 expression and better models natural pathogenesis of cancers where transformed cells usually arise within an environment of largely normal cells. Experiment Overall Design: Genetically engineered mice capable of conditionally expressing the human synovial sarcoma-associated SYT-SSX2 fusion oncogene were mated with genetically engineered mice expressing the CreER fusion protein from ROSA locus. The progenies harboring both CreER and SYT-SSX2 were followed up with or without tamoxifen injection. Tumors were generated in these mice that were dissected out, RNA extracted, and subjected to expression profiling by microarray analysis.
Project description:Most BRCA1-deficient BLBCs carry a dysfunctional INK4-RB pathway. Thus, we have created genetically engineered mice with Brca1 loss and deletion of p16INK4A, or separately p18INK4C, to model the deficient INK4-RB signaling in human BLBC. By using these mutant mice and human BRCA1 deficient and proficient breast cancer tissues and cells, we tested if there exists a druggable target in BRCA1 deficient breast cancers.
Project description:The circadian clock controls the expression of nearly 50% of protein coding genes in mice, and most likely in humans as well. Therefore, disruption of the circadian clock is presumed to have serious pathological effects including cancer. However, epidemiological studies on individuals with circadian disruption because of night shift or rotating shift work have produced contradictory data not conducive to scientific consensus as to whether circadian disruption increases the incidence of breast, ovarian, prostate or colorectal cancers. Similarly, genetically engineered mice with clock disruption do not exhibit spontaneous or radiation-induced cancers at higher incidence than wild-type controls. Because many cellular functions including the cell cycle and cell division are, at least in part, controlled by the molecular clock components (CLOCK, BMAL1, CRYs, PERs), it has also been expected that appropriate timing of chemotherapy may increase the efficacy of chemotherapeutic drugs and ameliorate their side effect. However, empirical attempts at chronochemotherapy have not produced beneficial outcomes. Using mice without and with human tumor xenografts, sites of DNA damage and repair following treatment with the anticancer drug cisplatin have been mapped genome-wide at single nucleotide resolution and as a function of circadian time. The data indicate that mechanism-based studies such as these may provide information necessary for devising rational chronochemotherapy regimens.
Project description:In metastatic breast cancer, HER2 activating mutations frequently co-occur with mutations in the PIK3CA, TP53, or E-cadherin genes. Of these co-occurring mutations, HER2 and PIK3CA mutations are the most prevalent gene pair, with approximately 40% of HER2 mutated breast cancers also having activating mutations in PIK3CA. To study the effects of co-occurring HER2 and PIK3CA mutations, we bred genetically engineered mice with the HER2V777L; PIK3CAH1047R transgenes (HP mice) and studied the resulting breast cancers both in vivo as well as ex vivo using cancer organoids.