Role of MAG1 proteins in invasiveness of human colorectal cancer cells

Introduction: MAGI -1 plays an essential role in cancer metastasis. We aimed to study the expression of MAGI -1, -2 and -3 in colorectal cancer tissue with specific focus on the role of MAGI -1 in colorectal cancer metastasis, through its function in the maintenance of cell-to-cell tight junctions. Materials and Methods: MAGI -1, -2 and -3, expression was determined in colorectal cancer tissue by using Q-PCR and RT-PCR. MAGI -1 knockdowns were created in cancer cell lines by electroporation method and were confirmed on RT- PCR, morphology and immunofluorescence. The impact of aberrantly expressed MAGI -1 on adhesion, invasion and migration of colorectal cancer tissue was studied by using trans-epithelial resistance (TER) and electrical cell impedance (ECIS) assays. Results: Q-PCR was consistent with the reduced expression of MAGI-1, -2 and -3 in colorectal cancer tissue. Survival curves showed reduced survival in cohort with reduced MAGI expression. MAGI -2 lacked expression on RT-PCR. MAGI -1 KDs showed decrease trans-epithelial resistance in the KDs. Reduced electrical resistance across epithelial cell lines in MAGI -1 KDs and also reduced adhesion and increase in migratory function was observed in MAGI -1 KDs on Trans-epithelial resistance (TER) and electronic cell impedance sensing (ECIS) experiments respectively. Conclusion: Our experimental work suggests that MAGI-1 plays a vital role in maintaining the barrier function of tight-junctions in colorectal cancer tissue, which when knocked down, has a significant implication in colorectal cancer metastasis.