BACKGROUNDIt has been proved that selenium has remarkable effects in the prevention of cancer and proliferation inhibition for breast cancer and prostate cancer. Up to now, little is known, however, if methylseleninic acid (MSA) has the anticancer effect on lung cancer or not. The objective of this study is to detect the effect of MSA on proliferation inhibition and apoptotic induction for human high-metastatic large cell lung cancer cell line L9981, and to explore the molecular mechanisms.

METHODSThe changes of proliferation, clone formation, apoptotic level and cell cycles were detected in L9981 by trypan blue staining, clone formation suppression test, and flow cytometry before and after treating with different concentration of MSA. The expression level of proliferative-related and apoptotic-related genes was also determined in L9981 by flow cytometry.

RESULTS(1)The proliferation ability of L9981 was remarkably inhibited at the concentration of 0.5μmol/L of MSA (P < 0.05), and the cells were arrested at G0/G1 phase after treating with the same concentration. (2)Apoptosis of L9981 was remarkably induced by MSA at the concentration of 2.5μmol/L (P < 0.05). (3)The clone formation ability of L9981 was significantly suppressed by MSA at the concentration of 5.0μmol/L (P < 0.05). (4)The expression levels of P53, P21, Fas, FasL and Bax were remarkably up-regulated after treatment with MSA.

CONCLUSIONS(1)MSA can significantly suppress the proliferation and clone formation ability of human high-metastatic large cell lung cancer cell line L9981, and also induce apoptosis of L9981. (2)The anticancer effects of MSA might be related to regulate the expression of cell cycle-related genes and apoptotic-related genes in the human high-metastatic large cell lung cancer line L9981.