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AIM To investigate the effects of diosgenin on autophagy of human osteosarcoma cells.METHODS Human osteosarcoma MG63 and U2OS cells with or without exposure to diosgenin had their proliferation detected by MTT assay,their ultrastructure observed by transmission electron microscopy,their expression of autophagy protein Beclin1 observed by immunofluorescence staining,and their expressions of autophagy molecular markers LC3,Beclin1 and PI3K/Akt/mTOR signaling pathway related proteins detected by Western blot.The MG63 and U2OS cells cotreated with diosgenin and PI3K pathway inhibitor LY294002 had the expression of Beclin1 mRNA detected by RT-qPCR.The MG63 and U2OS cells cotreated with autophagy inhibitor 3-methyladenine(3-MA)had their inhibition rate of proliferation detected by MTT assay,their expression of cleaved-caspase3 protein detected by Western blot,and their expression of caspase3 mRNA detected by RT-qPCR.RESULTS Upon osteosarcoma MG63 and U2OS cells,diosgenin inhibited their proliferation,promoted the generation of autophagosomes,increased the protein expression of LC3 Ⅱ and Beclin1(P<0.05,P<0.01),reduced the protein expression of LC3 I(P<0.01),and inhibited the protein phosphorylation level of PI3K/Akt/mTOR pathway(P<0.05,P<0.01),whose effects were offset by the intervention with autophagy inhibitors in terms of the reduced proliferation inhibition and down-regulated expressions of caspase3 mRNA and cleaved-caspase3 protein(P<0.01).CONCLUSION Diosgenin can inhibit the proliferation of osteosarcoma cells and induce their autophagy leading to their death and autophagy apoptosis,which may be related to the activation of PI3K/Akt/mTOR signaling pathway and up-regulation of the expression of LC3 Ⅱ and Beclin1 proteins.
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<p><b>OBJECTIVE</b>To study the regulation of the mucin protein in colon cancer cell line HT-29 by recombinant human interleukin-6(rIL-6) and to further elucidate the development of colon cancer.</p><p><b>METHODS</b>The HT-29 cells were treated with different concentrations of rIL-6(1, 2, 5, 10 and 20 μg/L), then flow cytometry and RT-PCR were used to detect the expression of mucin1 and mucin2. Transwell invasion assay was used to observe the effect of invasion capability of rIL-6 to HT-29 cells.</p><p><b>RESULTS</b>In colon cancer, the expression of mucin 1 could be promoted by rIL-6 with concentration above 2 μg/L, the expression rates were(12.5±1.6)%, (26.6±2.7)%, (33.9±2.8)% and (58.9±2.5)%, respectively, higher than (8.0±0.8)% in the negative controls (P<0.01), meanwhile, the expression of mucin 2 decreased by rIL-6 with concentration above 2 μg/L, the expression rates were(30.5±2.6)%, (17.0±2.7)%, (11.0±2.0)% and (5.3±1.8)%, respectively, lower than (41.6±3.6)% in negative control(P<0.01). With the increase in rIL-6 concentration, the invasion of HT-29 cells was enhanced.</p><p><b>CONCLUSIONS</b>In colon cancer, the expression of mucin1 can be promoted by rIL-6, while the expression of mucin2 can be inhibited. IL-6 is a promoting effect factor in colon cancer invasion and metastasis.</p>