Expressions of NHERF1 and β-catenin in malignant melanoma cell lines (A375, M14 and MV3) and their significance

Objective To investigate the expressions of Na+/H+ exchanger regulatory factor 1 (NHERF1) and β-catenin in human melanoma cell lines A375,M14 and MV3,as well as their significance.Methods Three human melanoma cell lines A375,M14,MV3 as well as melanocytes isolated from a healthy 8-year-old boy were cultured in vitro.Real-time fluorescence-based quantitative PCR was performed to detect the mRNA expressions of NHERF1 and β-catenin,immunocytochemistry and Western blot to quantify the protein expression of NHERF1 and β-catenin in these cells,and methyl thiazolyl tetrazolium (MTT) assay to evaluate the proliferative activity of these cells.Results NHERF1 and β-catenin were expressed in the membrane of melanocytes,and in the cytoplasm and/or nuclei,but not in the membrane of these melanoma cell lines.Of the three melanoma cell lines,only a small part of MV3 cells showed a weak immunocytochemical expression of NHERF1 in cytoplasm with the lowest expression level of NHERF1 mRNA,whereas A375 cells exhibited the strongest immunocytochemical expression of NHERF1 in cytoplasm and nuclei with the highest expression level of NHERF1 mRNA.As Western blot analysis showed,NHERF1 protein was undetectable in MV3 cells,but strongly expressed in A375 cells.The proliferation of MV3 cells was faster than that of A375 cells and M14 cells.Meanwhile,MV3 cells displayed the strongest immunocytochemical expression of β-catenin in cytoplasm and nuclei,with the highest level of mRNA and protein expression of β-catenin; A375 and M14 cells showed a relatively weaker expression of cytoplasmic β-catenin,with a decrease in the expression intensity of β-catenin mRNA and protein.Conclusions The cytoplasmic expression level of NHERF1 may be associated with the proliferative activity of melanoma cells,and it seems that the lower the expression level of NHERF1,the faster the cell proliferation.NHERF1 and β-catenin are differentially expressed in these melanoma cell lines. Key words: Melanoma;  NHERF1;  β-catenin