Project description:Cancer is considered as a disease of a specific organ, but its effects are felt throughout the body. The systemic effects of cancer can lead to weakness in muscles and heart, which hastens cancer-associated death. miR-486 is a myogenic microRNA and its reduced expression in skeletal muscle is observed in muscular dystrophy. Muscle-specific transgenic expression of miR-486 using muscle creatine kinase promoter (MCK-miR-486) partially rescues skeletal muscle defects in muscular dystrophy animal models. We had previously demonstrated reduced circulating and skeletal muscle levels of miR-486 in several cancer types and lower miR-486 levels correlated with skeletal muscle defects and functional limitations in mammary tumor models. Therefore, skeletal muscle defects induced by cancer could resemble defects observed in various dystrophies, which could be reversed through skeletal muscle expression of miR-486. We performed functional limitations studies and biochemical analysis of skeletal muscles of MMTV-Neu transgenic mice that mimic HER2+ breast cancer and MMTV-PyMT transgenic mice that mimic luminal subtype B breast cancer and these mice crossed to MCK-miR-486 transgenic mice. miR-486 significantly prevented tumor-induced reduction in muscle contraction force, grip strength, and rotarod performance in MMTV-Neu, but not in MMTV-PyMT mice. In MMTV-Neu model, miR-486 reversed several of the cancer-induced changes in skeletal muscle including loss of p53, phospho-AKT, and phospho-laminin alpha 2 (LAMA2) and gain of phosphorylation of the pre-mRNA processing factor hnRNPA0 and the splicing factor SRSF10. LAMA2 is a part of the dystrophin-associated glycoprotein complex, and its loss-of-function mutation is associated with congenital muscular dystrophy. Thus, similar to muscular dystrophy, miR-486 has the potential to reverse skeletal muscle defects and cancer burden in select cancer types.
Project description:The objective of this study was to determine the effect of Thyroid Hormone Responsive Protein Spot14 (Spot14) loss on the gene expression profiles of tumors from MMTV-Polyomavirus middle-T antigen (PyMT) mice. MMTV-PyMT/S14-heterozygous mice were crossed with S14-heterozygous mice and 1 cm tumors from MMTV-PyMT control (wild-type S14) or MMTV-PyMT/S14-null offspring were profiled using Affymetrix gene arrays. Tumor latency was not different between groups; however, tumors lacking S14 grew significantly slower than control tumors. Loss of S14 also decreased the levels of de novo synthesized fatty acids in mammary tumors. In additional studies, performed on MMTV-Neu mice, we found that S14 overexpression was associated with increased tumor cell proliferation and elevated levels of tumor fatty acids. Gene expression profiling revealed that S14 loss and overexpression in mouse mammary tumors altered pathways associated with proliferation and metabolism. This study provides important information about the role of S14 in mammary tumorigenesis and tumor metabolism. Microarray analysis was performed on 4 mammary tumors from MMTV-PyMT mice and 4 tumors from MMTV-PyMT/S14-null mice.
Project description:The objective of this study was to determine the effect of Thyroid Hormone Responsive Protein Spot14 (Spot14) loss on the gene expression profiles of tumors from MMTV-Polyomavirus middle-T antigen (PyMT) mice. MMTV-PyMT/S14-heterozygous mice were crossed with S14-heterozygous mice and 1 cm tumors from MMTV-PyMT control (wild-type S14) or MMTV-PyMT/S14-null offspring were profiled using Affymetrix gene arrays. Tumor latency was not different between groups; however, tumors lacking S14 grew significantly slower than control tumors. Loss of S14 also decreased the levels of de novo synthesized fatty acids in mammary tumors. In additional studies, performed on MMTV-Neu mice, we found that S14 overexpression was associated with increased tumor cell proliferation and elevated levels of tumor fatty acids. Gene expression profiling revealed that S14 loss and overexpression in mouse mammary tumors altered pathways associated with proliferation and metabolism. This study provides important information about the role of S14 in mammary tumorigenesis and tumor metabolism.
Project description:To investigate the gene expression profile of different cancer associated fibroblasts (CAF) subpopulations, we harvested tumors and sorted 4 CAF populations from 3 FVB background 10-week-old MMTV-PyMT mice.
Project description:MMTV-PyMT transgenic FVBN mice spontaneously developed breast tumors. Two tumors were collected as replicate samples, and cells from the dissociated tissue were sorted into 2 cancer stem cell (CSC) populations, along with the remaining non-CSCs. The samples were submitted for RNAseq to generate differential gene expression profiles of the breast tumor CSC populations.
Project description:Previously, lncRNA Malat1 knockout mice were generated by insertional inactivation. By crossing this line to MMTV-PyMT mammary tumor mouse model, we produced PyMT;Malat1 wild-type (WT) and PyMT;Malat1 knockout (KO). Furthermore, we generated Malat1 transgenic mice by targeting ROSA26 locus and bred them to PyMT;Malat1 knockout mice to produce Malat1-rescued PyMT;Malat1 knockout;Malat1 transgenic animals (TG). Using mammary tumors from the three groups of animals, we performed RNA-Seq analysis to identify differentially up-regulated genes in KO tumors to find novel target genes of YAP-TEAD pathway.