The Effect Of Oncostation M On The Growth Of Liver-derived Cell Lines In Vitro

Cytokine oncostatin M (OSM) has profound effects on proliferation and differentiation of cell lines from tumor types. OSM treated cells show reduced growth rate and differentiation phenotypes. Meanwhile, OSM is capable of stimulating maturation of hepatic parenchymal cells in embryonic liver. But, the mechanisms underlying tumorigenesis of liver carcinoma has not been fully elucidated. A clear understanding OSM regulates the growth and differentiation of tumor and stem cell lines from liver would provide insights into this complicated disease.In this study, the expression plasmid pNl-OSM-EGFP constructed by the insertion of the complete ORF of human OSM into pEGFP-Nl vector. By transfecting Chinese hamster ovary (CHO) cell line. The stable cell line CHO-OSM-EGFP was obtained after screening with G418, and single colony was picked up under the fluorescence microscope. The clonality of the cells were checked by fluorescence activated cell sorting (FACS), the mRNA expression was examined by RT-PCR using OSM primers. In order to demonstrate the effect of OSM on the growth of liver-derived stem cells and tumor cells, the cultured supernatant of cells transfected with pOSM-EGFP-Nl or pEGFP-Nl were collected and added to the HTC or WB-F344 culture plates with the different final concentrations. The cells after 4 ~ 7 days cultivation were analyzed by FACS. Our primary results showed that the cultured supernatant collected from pOSM-EGFP-Nl transfected cells could induce apoptosis of HTC cells, but no influence on the distribution ofeach phases of the cell cycle; In contrast to the above, the same supernatant arrested WB-F344 stem cells at GO-G1 phase of cell cycle, cell proportion in the M and S phase decreased but no apoptosis could be observed. And, the growth arrest caused by the supernatant was accompanied by cellular phenotypic changes. The mechanism of different effect of OSM on liver-derived normal and malignant cells should be further explored, which may open new avenues for developing alternative treatment of liver and other cancers.