[Overexpressing exogenous S100A13 gene and its effect on proliferation of human thyroid cancer cell line TT]

S100A13 is involved in tumor formation, and is highly expressed in human thyroid gland. This study was to investigate the effect of exogenous S100A13 overexpression on the proliferation of human thyroid cancer cell line TT.

The eukaryotic expression plasmid pCDNA3.1/NT-GFP-S100A13 and empty vector pCDNA3.1/NT-GFP were transfected into TT cells. The cells were selected by G418. The expression of green fluorescent protein (GFP) was observed under laser scanning microscope, and the expression of S100A13 mRNA and protein was detected by real-time reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. The effects of S100A13 on cell proliferation and cell cycle progression were measured by cell growth curve and flow cytometry.

TT-S100A13-GFP and TT-GFP cells, which separately expressed S100A13 and pCDNA3.1/NT-GFP, were constructed successfully. TT-S100A13-GFP cells grew faster than TT-GFP and TT cells [(2.30+/-0.24) x 10(5) vs. (1.40+/-0.25) x 10(5) and (1.50+/-0.22) x 10(5) at the 7th day of cell culture, P<0.05]; both S phase proportion and G2/M phase proportion were significantly higher in TT-S100A13-GFP cells than in TT-GFP and TT cells [(6.47+/-0.14)% vs. (5.86+/-0.23)% and (5.99+/-0.28)% at S phase, P<0.05; (50.27+/-0.66)% vs. (39.39+/-0.23)% and (39.64+/-0.64)% at G2/M phase, P<0.05].

Exogenous S100A13 gene overexpression could accelerate cell proliferation, and promote cell cycle progression of TT cells from G0/G1 phase to S and G2/M phase.