tailieunhanh - Báo cáo khoa hoc : Increased expression of nonmuscle myosin IIs is associated with 3MC-induced mouse tumor

Administration of the chemical carcinogen, 3-methylcholanthrene (3MC), in the hind leg induces the progressive formation of tumors in mice within 110 days. Previous reports suggest that transformation of muscle cells to atypical cells is one of the causes of tumor formation. | IFEBS Journal Increased expression of nonmuscle myosin IIs is associated with 3MC-induced mouse tumor Shekhar Saha Sumit K. Dey Provas Das and Siddhartha S. Jana Department of BiologicalChemistry Indian Association for the Cultivation of Science Jadavpur India Keywords 3-methylcholanthrene fibroblast nonmuscle myosin II transformation tumor Correspondence S. S. Jana Department of Biological Chemistry Indian Association for the Cultivation of Science 2A B Raja S. C. Mullick Road Jadavpur Kolkata-700032 India Fax 91 33 2483 6561 Tel 91 33 2473 4971 Ext 519 E-mail bcssj@ Received 11 June 2011 revised 27 July 2011 accepted 12 August 2011 doi Administration of the chemical carcinogen 3-methylcholanthrene 3MC in the hind leg induces the progressive formation of tumors in mice within 110 days. Previous reports suggest that transformation of muscle cells to atypical cells is one of the causes of tumor formation. Molecular events that lead to transformation of normal cells to atypical cells are not well understood. Here we investigate the effect of 3MC on the expression of nonmuscle myosin IIs NM IIs which are known to be involved in cell migration division and adhesion. Mass spectroscopy analysis reveals that tumor tissue contains NM II-A 34 II-B and only II-C of total NM IIs whereas these three isoforms of NM IIs are undetectable by mass spectroscopy in normal tissue associated with the tumor NTAT from the hind leg. Quantification of heavy chain mRNAs of NM II suggests that tumor tissue contains and more of NM II-A and II-B respectively compared with NTAT. Unlike NM II-B which is detected only after tumor formation II-A is detectable as early as day 7 after a second dose of 3MC. Immunofluorescence confocal microscopy reveals that fibroblast cells which are sparsely distributed in normal tissue are densely populated but of atypical shape in the tumor. These findings suggest