Fibroblast Growth Factor 3 Is Associated with Tongue Squamous Cell Carcinoma: A Controlled Study

Abstract

Objective. To explore the effects of fibroblast growth factor 3 (FGF3) on the proliferation, cell cycle, and apoptosis of the tongue squamous cell carcinoma SCC-9 cell line (SCC-9). Methods. We measured the proliferation of SCC-9 cells in a control group, an FGF3 intervention group, and a fibroblast growth factor (FGFR) inhibitor intervention group in cholecystokinin octapeptide (CCK-8) experiments. We studied effects of FGF3 on the cell cycle and apoptosis of tongue cancer cells using flow cytometry. We further explored the IRS1/PI3K/AKT signaling pathway by measuring BCL-2 and Bcl-2 Associated X-protein (BAX) mRNA and protein levels with RT-PCR and western blot, respectively. Results. Results from the CCK-8 experiment showed that survival rates of cells in the control group, FGF3 intervention group, and FGFR inhibitor intervention group were $100.000\%\pm 4.026\%$ , $136.330\%\pm 9.779$ %, and $83.199\%\pm 4.954$ %, respectively; survival rates of SCC-9 cells in all three groups were statistically significant ( $P<0.05$ ). Compared with that in the control group, the ratio of cells in G0/G1 phase in the FGFR inhibitor intervention group was higher ( $P<0.05$ ) and that in G2/M phase was lower, while the FGF3 intervention group showed opposite results ( $P<0.05$ ). The apoptosis rate of tongue cancer cells differed significantly between the FGFR inhibitor intervention and the control groups ( $P<0.05$ ). The mRNA and protein expression levels of IRS1, PI3K, and BCL-2 were all increased in the FGF3 intervention group ( $P<0.05$ ), while BAX mRNA and protein expression levels were decreased ( $P<0.05$ ). The mRNA expression levels of protein kinase B (AKT) showed no differences between groups. The p-AKT protein was overexpressed, while the total amount of AKT protein remained stable ( $P<0.05$ ). Conclusion. FGF3 contributes to the proliferation of SCC-9 cells by increasing the proportion of cells in G2/M phase. Therefore, appropriately timed inhibition of FGF3 can potentially promote tumor apoptosis through the IRS1/PI3K/AKT signaling pathway. Our results demonstrate the role of FGF3 in the tumor microenvironment in tongue squamous cell carcinoma SCC-9 cells and suggest new therapeutic targets.