The relationship between PTEN expression and anoikis in human lung carcinoma cell lines.

The relationship between PTEN expression and anoikis in 8 different human lung carcinoma cell (HLCC) lines, and PKB and FAK effects in the process were studied. Northern blots and Western blots were carried out to analyze PTEN expression at mRNA and protein levels and the phosphorylation level of PKB /FAK in HLCC lines, and anoikis was examined by using DNA Ladder analysis. It was shown that PTEN mRNA expression was at similar level in 8 HLCC lines. But protein expression did not accord with it's mRNA expression. There were no PTEN protein detectable in 95C 95D and A(1) cells; very low PTEN protein was expressed in A(549) and A(4) A(7) cells; and high PTEN protein expressed in H(460) cells. There were no deletion and point mutation in 95D and H(460) cells; and mRNA stability in 95D cells was much lower than that of H(460) cells. Anoikis was observed in PTEN high-expressed H(460) cells with serum lack and loss of adhesion, and 10% serum prevented it from anoikis. PTEN decreased the phosphorylation level of PKB and down-regulated FAK expression in HLCC. These results suggest that PTEN expression is different in 8 HLCC lines, and PTEN was involved in anoikis.