Role of stromal cell derived factor/CXC chemokine receptor axis in regulation of expression of CD133 in gastric cancer cells via PI3K/Akt pathway in vitro

Abstract

Objective To observe the effects of stromal cell derived factor/CXC chemokine recep- tor （SDF-1α/CXCR4） axis on the expression of CD133 via PI3K/Akt signaling pathway in gastric cancer （GC） in vitro. Methods The morphological expression of CXCR4, Akt, p-Akt and CD133 in KATO-1α cells were detected by using immunocytochemistry. SDF-1α, AMD3100 and LY294002 were respectively used to stimulate/inhibit KATO-m ceils. The semi-quantitative enzyme-linked polymerization assay for CXCR4 and CD133 mRNA expression was applied. The expression levels of CXCR4, Akt, p-Akt and CD133 proteins were detected by using Western blotting. Results Positive staining of CXCR4, Akt, p-Akt and CD133 was observed in the cultured cells. The expression levels of CXCR4 protein （0. 980 ±0. 083）, p-Akt protein （0. 770 ± 0. 071 ）, and CD133 protein （0. 890 ±0. 078 ） were significantly higher （ P 〈 0. 05） in SDF-1α group than in control group （0. 750 ±0. 042, 0. 680 ±0. 038, 0. 720 ±0. 034 respectively）. The expression levels of CD133 mRNA （0. 890 ±0. 061 ） were significantly higher （P 〈 0. 05 ） in SDF-1α group. In AMD3100 group, the expression levels of CXCR4 protein （0. 430 ±0. 055）, p-Akt protein （0. 350 ±0. 050） and CD133 protein （0. 110 ±0. 060） were decreased significantly as compared with those in control group （0. 750 ±0. 042, 0. 680 .SO. 038, and 0. 720 ±0. 034 respectively, P 〈0. 05）. In LY294002 group, the expression levels of p-Akt protein （ 0. 100 ± 0. 033 ） and CD133 protein （0. 440 ±0. 055 ） were decreased significantly as compared with those in control group （0. 680 ±0. 038 and 0. 720 ± 0. 034 respectively, P 〈0. 05） ; In comparison with that in control group （0. 540 ±0. 036）, CD133 mRNA （0. 310 ±0. 021 ） was decreased significantly （P 〈0. 05）. Conclusion The axis of SDF-la/CXCR4 stimulated or inhibited can up-regulate or down-regulate the CD133 expression via PI3K/Akt signaling pathway in GC in vitro. Key words: Gastric cancer; Stromal cell derived factor/CXC chemokine receptor; CD133; PI3K/Akt pathway