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:Our research aims to chart the circRNA expression profile and assess their impact on the lung PMN. We developed a lung PMN model and employed comprehensive RNA sequencing to analyze the differences in circRNA expression between normal and pre-metastatic lungs.Overall, our study highlights the crucial role of circRNAs in the formation of lung PMNs, supporting their potential as diagnostic or therapeutic targets for lung metastasis.
Project description:Seventy percent of women with ovarian cancer develop resistance to cisplatin, contributing to persistently high mortality rates. Understanding the mechanisms behind this resistance is crucial for developing improved therapies. Matrix metalloproteinase 3 (MMP3) is elevated in ovarian cancer patients, but its role in cisplatin resistance remains underexplored. We observed significantly higher MMP3 protein and mRNA levels in cisplatin-resistant high-grade serous ovarian cancer (HGSOC) cells compared to cisplatin-sensitive cells, with further increases following cisplatin treatment. Kaplan‒Meier analysis indicated that patients with lower MMP3 levels have better survival outcomes. MMP3 knockdown via siRNA reduced cell viability, proliferation, and invasion, effects enhanced by cisplatin; however, a chemical MMP3 inhibitor did not replicate these effects. To better understand MMP3’s role, we conducted RNA sequencing to analyze gene expression changes and used immunoprecipitation with mass spectrometry to identify MMP3-interacting proteins, making this the first study to explore this in cisplatin-resistant ovarian cancer. Surprisingly, multiple injections of liposomal MMP3-siRNA increased tumor size in a mouse model, while combining MMP3-siRNA with cisplatin reduced tumor growth. These findings highlight MMP3’s complex role in cisplatin resistance and raise concerns about its targeting in vivo.
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.