Project description:Cancer metastasis remains an important unsolved problem. Matrix metalloproteinases (MMPs) have been shown to promote cancer cell transformation, migration, invasion, and metastasis through alteration of the extracellular microenvironment, and alter intracellular signaling and genome status. In addition, recent studies have shown intracellular and intranuclear localization, as well as roles of MMPs. In the present study, we examined gene expression signatures of high- and low-metastatic mouse colon cancer cells, and found that Mmp3 was expressed at the highest level in the high-metastatic cells. Profound nuclear localization of Mmps was found in primary explant sites as well as in areas of metastasis in lungs. In addition to the native 50-kDa Mmp3, a short 25-kDa PEX domain and active Mmp3 dimer were found in metastatic cancer cells, indicating novel roles for these forms. Knockdown of Mmp3 attenuated cancer cell viability, migration, and invasion in vitro, along with metastasis in an in vivo transplantation model, as well as cancer cell migration and invasion. These findings suggest that MMPs including intracellular, short, and dimerized forms are involved with malignant progression of cancer, thus they may be suitable as biomarkers and therapeutic targets.
Project description:High Arid4b promotes mammary tumor growth and metastasis in mouse model systems, and is associated with poor metastasis-free survival in human breast cancer patients. Through shRNA-mediated knockdown, we demonstrated that loss of Arid4b significantly inhibits the ability of mouse breast cancer cells to metastasize to the lungs. We performed microarray expression and subsequent network analysis to identify genes diferentially regulated as a consequence of Arid4b knockdown. The highly metastatic mouse breast cancer cell line 6DT1 was transduced with lentiviral shRNAs targeting Arid4b (RMM4534-NM_194262, Open Biosystems) or scrambled control in the same pLKO.1 vector backbone. Stably transduced cells were selected with puromycin, then total RNA was isolated from pooled clones.
Project description:We found that BAP1 (BRCA1 Associated Protein-1) shows loss of heterozygosity in over 25% of pancreatic cancer patients and functions as tumor suppressor. Conditional deletion of Bap1 in murine pancreas led to genomic instability, accumulation of DNA damage, and an inflammatory response that evolved to pancreatitis with full penetrance. Concomitant expression of oncogenic KrasG12D led to malignant transformation and development of invasive and metastatic pancreatic cancer. At the molecular level, BAP1 maintains the integrity of the exocrine pancreas by regulating genomic stability and its loss confers sensitivity to radio- and platinum-based therapies.
Project description:Abstract:
Accumulating experimental and clinical evidence suggest that the immune response to cancer is not exclusively anti-tumor. Indeed, the pro-tumor roles of the immune system - as suppliers of growth and pro-angiogenic factors or defenses against cytotoxic immune attacks, for example - have been long appreciated, but relatively few theoretical works have considered their effects. Inspired by the recently proposed "immune-mediated" theory of metastasis, we develop a mathematical model for tumor-immune interactions at two anatomically distant sites, which includes both anti- and pro-tumor immune effects, and the experimentally observed tumor-induced phenotypic plasticity of immune cells (tumor "education" of the immune cells). Upon confrontation of our model to experimental data, we use it to evaluate the implications of the immune-mediated theory of metastasis. We find that tumor education of immune cells may explain the relatively poor performance of immunotherapies, and that many metastatic phenomena, including metastatic blow-up, dormancy, and metastasis to sites of injury, can be explained by the immune-mediated theory of metastasis. Our results suggest that further work is warranted to fully elucidate the pro-tumor effects of the immune system in metastatic cancer.
Project description:Colorectal cancer (CRC) is one of the most prevalent tumors, with a high mortality rate. Nearly half of CRC patients develop metastasis, which accounts for as many as 90% of CRC-related deaths. In the metastasis process, cancer cells exhibit altered dependency on specific metabolic pathways and some of the metabolites discovered might be useful as potential diagnostic biomarkers. To identify metabolic pathway dependencies in CRC metastasis, mass spectrometry-based untargeted metabolomic analysis was performed in two pairs of CRC cell lines with different metastatic abilities. Each pair of cell lines was comprised of primary and metastatic colorectal cancer cell lines (SW480 vs. SW620; HT-29 vs. COLO 205). Relative levels of intracellular metabolites distinguished high-metastatic CRC cells from low-metastatic CRC cells.
Project description:Cancer metastasis is a fetal problem that claims life of over 90% of cancer patients. It is hypothesized that cancer stem cells (CSCs) mediate cancer metastasis and such cells are often resistant to chemotherapy. Studying BRCA1 associated cancers, we found that CSCs form fillopodia and protrusions enriching for active forms of ezrin/radixin/moesin proteins and they have a much higher potential to metastasize than non-CSCs. Microarray analysis indicated that many pathways related to cell adhesion, extracellular matrix and cytoskeleton were differentially regulated in CSCs. Although inhibition of cytoskeleton remodeling by cisplatin treatment retarded CSC motility and cancer metastasis, drug resistant cancers eventually emerge containing markedly increased number of CSCs. This event is at least partially attributed to the activation of PI3K/mTOR signaling, and can be significantly inhibited by the treatment of rapamycin. These results provide strong evidence that cytoskeletal rearrangement and PI3K/mTOR signaling play a distinct role in mediating CSC mobility and viability, and blocking of both pathways in CSCs synergistically inhibits primary and metastatic cancer growth in BRCA1 associated tumors. The sorted subpopulations based upon CD24, CD29 expression were used in the microarray analysis that was performed with 3 independent biologic sample sets.