Project description:Comparison of gene expression data between control and MFP-treated C4-HD tumors. The role of active antitumor immunity in hormone receptor positive (HR+) breast cancer has been historically underlooked. The aim of this study was to determine the contribution of the immune system to antiprogestin-induced tumor growth inhibition using a hormone-dependent breast cancer model. BALB/c-GFP+ bone marrow (BM) cells were transplanted into immunodeficient NSG mice to generate an immunocompetent NSG/BM-GFP+ (NSG-R) mouse model. Treatment with the antiprogestin Mifepristone (MFP) inhibited growth of 59-2-HI tumors with similar kinetics in both animal models. Interestingly, MFP treatment reshaped the tumor microenvironment, enhancing the production of proinflammatory cytokines and chemokines. Tumors in MFP-treated immunocompetent mice showed increased infiltration of F4/80+ macrophages, NK, and CD8 T cells, displaying a central memory phenotype. Mechanistically, MFP induced immunogenic cell death in vivo and in vitro, as depicted by the expression and subcellular localization of the alarmins calreticulin and HMGB-1 and the induction of an immunogenic cell death gene program. Moreover, MFP-treated tumor cells efficiently activated immature dendritic cells, evidenced by enhanced expression of MHC-II and CD86, and induced a memory T cell response, attenuating tumor onset and growth after re-challenge. Finally, MFP treatment increased the sensitivity of HR+ 59-2-HI tumor to PD-L1 blockade, suggesting that antiprogestins may improve immunotherapy response rates. These results contribute to a better understanding of the mechanisms underlying the antitumor effect of hormonal treatment and the rational design of therapeutic combinations based on endocrine and immunomodulatory agents in HR+ breast cancer.
Project description:Introduction: Over the past several years, we have been interested in understanding the mechanisms by which hormone-dependent (HD) mammary carcinomas grow in the absence of the stimulatory hormone. We have hypothesized that the stromal compartment plays a pivotal role in the acquisition of the hormone-independent (HI) phenotype by providing stimulatory factors that replace the proliferative effects of the hormone. Methods: We used DNA microarrays to compare the gene expression profiles of tumors from the MPA mouse breast cancer model, one hormone-dependent (C4-HD) and one hormone-independent (C4-HI), using whole tumor samples or laser-captured purified stromal and epithelial cells obtained from the same tumors. The expression of selected genes was validated by immunohistochemistry and immunofluorescence assays. Results: We identified 413 genes that were expressed in tumor stroma but not in epithelial cells. Eighty-five percent of these genes were upregulated, whereas the remaining 15% were downregulated in C4-HI tumors relative to their expression in the C4-HD tumor stroma. Several matrix metallopeptidases, including Mmp13, Mmp3, Mmp10 and Mmp9, were overexpressed in the C4-HI tumor microenvironment. On the other hand, 1100 genes were specifically expressed in the tumor parenchyma. Among them, the 29% were upregulated, whereas the remaining 71% were downregulated, in C4-HI relative to C4-HD tumor epithelium. Steap, Pdgfc, Runx2, Cxcl9 and Sdf2 were among the genes with high expression in the C4-HI tumor parenchyma. Interestingly, we found that Fgf2 was one of the few genes upregulated by MPA in C4-HD tumors, confirming its pivotal role in regulating tumor growth in this model. Conclusions: We demonstrate a gene expression profile that distinguishes epithelial from stromal cells in mammary tumors with different hormone dependence. Our results support the hypothesis that the tumor-associated stroma may contribute to hormone-independent tumor growth. The fact that Fgf2 was one of these few stimulatory genes is worth investigating. reference X sample
Project description:Introduction: Over the past several years, we have been interested in understanding the mechanisms by which hormone-dependent (HD) mammary carcinomas grow in the absence of the stimulatory hormone. We have hypothesized that the stromal compartment plays a pivotal role in the acquisition of the hormone-independent (HI) phenotype by providing stimulatory factors that replace the proliferative effects of the hormone. Methods: We used DNA microarrays to compare the gene expression profiles of tumors from the MPA mouse breast cancer model, one hormone-dependent (C4-HD) and one hormone-independent (C4-HI), using whole tumor samples or laser-captured purified stromal and epithelial cells obtained from the same tumors. The expression of selected genes was validated by immunohistochemistry and immunofluorescence assays. Results: We identified 413 genes that were expressed in tumor stroma but not in epithelial cells. Eighty-five percent of these genes were upregulated, whereas the remaining 15% were downregulated in C4-HI tumors relative to their expression in the C4-HD tumor stroma. Several matrix metallopeptidases, including Mmp13, Mmp3, Mmp10 and Mmp9, were overexpressed in the C4-HI tumor microenvironment. On the other hand, 1100 genes were specifically expressed in the tumor parenchyma. Among them, the 29% were upregulated, whereas the remaining 71% were downregulated, in C4-HI relative to C4-HD tumor epithelium. Steap, Pdgfc, Runx2, Cxcl9 and Sdf2 were among the genes with high expression in the C4-HI tumor parenchyma. Interestingly, we found that Fgf2 was one of the few genes upregulated by MPA in C4-HD tumors, confirming its pivotal role in regulating tumor growth in this model. Conclusions: We demonstrate a gene expression profile that distinguishes epithelial from stromal cells in mammary tumors with different hormone dependence. Our results support the hypothesis that the tumor-associated stroma may contribute to hormone-independent tumor growth. The fact that Fgf2 was one of these few stimulatory genes is worth investigating.
Project description:We have identified by RNA sequencing the molecular signaling pathways that are involved in skin tumor regression and that fail to happen in malignant not regressing skin tumors . mRNA profile from Keratoacanthoma tumors at 0 and 1 week post DMBA treatment was generated in duplicate for each timepoint analyzed
Project description:We have identified by RNA sequencing the molecular signaling pathways that are involved in skin tumor regression and that fail to happen in malignant not regressing skin tumors .
Project description:Prostate cancer is the most common, lethal malignancy in men. Although androgen withdrawal therapies are used to treat advanced disease, progression to a castration-resistant, end-stage is the usual outcome. In this study, the tested hypothesis was that the androgen receptor remains essential for the growth and viability of castration-resistant disease. Knocking down the androgen receptor in well-established tumors grown in castrated mice caused growth arrest, decreased serum PSA, and frequently regression and total eradication of tumors. Growth control of castration-resistant tumors appeared to be linked to the extent of androgen receptor knockdown, which triggers upregulation of many genes involved in apoptosis, cell cycle arrest, and inhibition of tumorigenesis and protein synthesis. Our findings provide proof of principle that in vivo knockdown of the androgen receptor is a viable therapeutic strategy to control and possibly eradicate prostate cancers that have progressed to the lethal castration-resistant state. C4-2 human prostate cancer cells stably expressing a tetracycline-inducible AR-targeted short hairpin RNA (shRNA) or scrambled shRNA were generated. These two cell lines were incubated in the absence of androgens with or without doxycycline hyclase (DOX). Comparison analysis of the gene expression profiles of C4-2 cells stably expressing AR shRNA + DOX and control cells (AR shRNA - DOX and scrambled shRNA ± DOX) was conducted to identify differentially regulated genes due to AR knockdown after normalization and data filtering. Genes were considered to be significantly different if the expression in the induced AR shRNA + DOX cells was at least 1.7-fold greater or 1.7-fold less than that seen in the control cells, with P< 0.05.
Project description:Gene expression changes were examined in transgenic MYC-driven liver cancers at different time points as tumors formed and upon early regression. Time points evaluated include: Control (non-tumor bearing), Pre-tumor (mice were removed from doxyclycine in their diet to induce MYC oncogene expression for 4-5 weeks), Tumor (tumor nodules from mice that had been off of doxycycline for 8-9 weeks) and Early tumor regression (tumor-bearing mice were placed back on doxycycline for 72 hrs to inhibit MYC oncogene expresion). MYC-Driven Mouse Tumor Models are described in Schahaf, et al., Nature, 2004 and Goga, et al., Nature Medicine, 2007. 11 Total Samples: 3 Control, 4 Pre-Tumor, 4 Tumor, 4 Early Tumor Regression. Control = LAP-tTA transgenic mice. Others = TRE-MYC x LAP-tTA double transgenic mice (doxy off).
Project description:Numerous case studies have reported spontaneous regression of metastases following tumor excision, but underlying mechanisms are elusive. Here we present a model of metastases regression and latency elicited by the removal of a primary tumor, and identify underlying mechanisms. Human breast cancer cells, expressing highly sensitive luciferase, were implanted into the mammary fat-pad of mice, and the progression of early stage micrometastases, was monitored. Upon establishment of micrometastases, the primary tumor was excised, inducing a robust regression of metastatic signal, resulting in latent foci. In vivo supplementation of tumor secretome immediately upon tumor excision diminished this regression, implicating primary tumor secreted factors in promotion of metastatic growth. In vitro, cancer cell conditioned medium reduced apoptosis and enhanced adhesion of non-confluent cancer cells, and induced angiogenesis in endothelial cells. Cytokine array and proteomic analysis of cancer cells secretome identified 359 extracellular secreted factors, with significant enrichment of angiogenic factors, growth factors activity, focal adhesion, apoptosis, and metalloprotease processes. In vivo blockade of four key potential mediators of these processes, IL-8, PDGFaa, Serpin E1 (PAI-1), and MIF, arrested development of micrometastases. Moreover, high protein levels of these four factors were correlated with poor patient outcome. These results demonstrate regression and latency of metastases following tumor excision and a crucial role for primary tumor secretome in promoting early metastatic stages, suggesting novel mechanisms to control minimal residual disease.
Project description:Prostate cancer C4-2B cells were cultured in enzalutamide in a dose-escalation manner. After sixty passages cells were resistant to enzalutamide, with a specific sets of genes been deregulated. We performed global gene expression analysis by cDNA microarrays to identify genes responsible for enzalutamide resistance in C4-2B-MDVR cells. Enzalutamide resistant C4-2B-MDVR cells were selected from C4-2B cells during long time enzalutamide treatment. Genes responsible for enzalutamide resistance were identified using C4-2B vs. C4-2B-MDVR RNA extraction and hybridization on Affymetrix microarrays.
Project description:Elucidating the genetic control of development of C3 and C4 photosynthesis. Atriplex rosea (C4) and Atriplex prostrata (C3) were studied along a leaf developmental gradient to compare development between C3 and C4. C3 Atriplex prostrata x C4 Atriplex rosea F1 hybrid were studied along the same developmental gradient and will aid in identifying regulatory elements involved in C3 and C4 leaf development.