Figure 1.

PTEN-4A is a more Potent Tumor Suppressor than PTEN-WT. (A) In the PTEN-4A mutant protein, the serine-threonine cluster (S380, T382, T383, S385) in the PTEN C-tail is replaced by alanine residues, converting it into an open/active conformer. (B) Lentiviral transduction, followed by puromycin selection, was used to stably express Flag PTEN-WT and Flag PTEN-4A proteins in PTEN deficient NSCLC cell line H1299. The expression levels of both PTEN-WT and PTEN-4A proteins were similar. (C) PTEN-4A inhibited cell proliferation significantly more than PTEN-WT in a standard cell proliferation assays (i). Even in the presence of a proliferative signal such as leptin, PTEN-4A remained a potent inhibitor of cell proliferation (ii). Data are derived from experiments performed in triplicates ± S.E. (n = 3, *p<0.05). (D) Cell proliferation assays on H1299, PTEN-WT and PTEN-4A cells measured by the ECIS method also revealed that PTEN-4A (black line) significantly suppressed cell proliferation as compared to PTEN-WT (pink line). (E) Likewise, PTEN-4A (blue line) significantly inhibited the migratory potential of H1299 lung cancer cells as compared to PTEN-WT (red line).