Expression of pSTAT5 in pancreatic carcinoma cells and effect of growth hormone on pSTAT5

Abstract

Objective To investigate the expression of pSTAT5 in 7 pancreatic carcinoma cell lines,and the change of expression of pSTAT5 in pancreatic carcinoma cells SW1990 after growth hormone (GH) treatment, and explore its molecular mechanism. Methods Human pancreatic carcinoma cell lines (SW1990, Cap-1, Colo, Mia, AsPc, P3, PANC1) were cultured in vitro, and Western blotting was used to detect the expression of pSTAT5 in these cell lines. SW1990 in exponential growth phase was collected and nude Balb/c mice were inoculated with SW1990 cells. When tumors became palpable after inoculation, mice (normal saline group). 1 h, 2 h and 24 h after the last dose of GH treatment, the mice were sacrificed.Western blotting was used to detect the expression of pSTAT5 in SW1990 and inoculation tumor cells after GH injection. Results Positive expression of pSTAT5 was observed in all human pancreatic carcinoma cell lines (SW1990, Cap-1, Colo, Mia, Aspc, P3, PANC1). 5 minutes after GH (50 ng/ml) stimulation, the expression of pSTAT5 in SW1990 was 0.57 ±0.05, which was significantly increased; and it reached 0.64 ±0.04 at 10 minutes, then decreased to 0.39 ±0.03 at 15 minutes, however, it remained higher than that in the control group at 1 h (0.33 ± 0.02 vs 0.25 ± 0.06), and its expression at 2 h was 0.26 ± 0.03 and returned to the normal level. The expression of pSTAT5 in xenograft was not significantly changed. Conclusions GH could rapidly up-regulate the expression of pSTAT5 in SW1990 but the effect lasted for a relatively short period. GH had no significant effect on the expression of pSTAT5 in xenograft. Key words: Pancreatic neoplasms; STAT5 transcription factor; Growth hormone; Signal transducing