[Role of PI3K/AKT signaling pathway in clonogenicity and tumorigenicity of CD90+ stem-like cells of the hepatocellular carcinoma cell line MHCC-97H].

Objective To investigate the influence of the PI3K/AKT signaling pathway on the proportion and characteristics of the stem-like CD90+ subpopulation of the human hepatocellular carcinoma (HCC) cell line MHCC-97. Methods MHCC-97H cultures were treated with the PI3K/AKT pathway inhibitor LY294002. The proportion of the CD90+ subpopulation was determined by flow cytometry, and the expression of related proteins was measured by Western blot. The clonogenicity of CD90+ and CD90- cells was measured by plate colony formation assay. The tumorigenicity was compared between CD90+ and CD90- subpopulations (with different concentrations) in xenograft experiments in nude mice, and the changes in tumorigenicity after the addition of LY294002 were evaluated. The changes in the expression of CD90, SHP2, P-AKT, and AKT in CD90+ and CD90- cell xenografts after the addition of LY294002 were examined. Data were analyzed using t test. Results LY294002 was capable of reducing the proportion of CD90+ HCC stem cells from 2.98%±0.08% to 0.78%±0.08% (t = 32.400, P < 0.01) and reducing the clonogenicity of CD90+ subpopulation from 95.13%±3.78% to 61.82%±7.23% (t = 7.617, P < 0.01). However, it showed no significant effect on the clonogenicity of CD90- subpopulation. LY294002 also reduced the tumorigenicity of CD90+ subpopulation and the expression of CD90, SHP2, and P-AKT in related HCC stem cells, but it did not significantly affect the expression of AKT. LY294002 had no significant inhibitory effect on the tumorigenicity of CD90- cells. Conclusion The CD90+ subpopulation of MHCC-97H cells has the characteristics of stem cells and is dependent on the PI3K/AKT signaling pathway. Key words: Carcinoma, hepatocellular; Stem cells; PI3K/AKT signaling pathways