Effects Of Cucurmosin On Proliferation Inhibition And EGFR Signal Pathway In Human Pancreatic Cancer Cells

Objective To investigate the effects of cucurmosin (CUS) on proliferation inhibition and the important molecule EGFR, and CUS combined with gefitinib (GEF) in human pancreatic cancer cells. Exploring the effects and mechanisms of CUS on PC is to provide a theoretical and experimental evidence for its anti‐PC potential clinical application.Methods1. SRB assay was used to detect proliferation inhibition in human pancreatic cancer cell lines PANC‐1and BxPC‐3in vitro after treatment of CUS alone and combined with GEF to find a synergistic effect.2. Colony forming assay was used to observe the colony forming efficiecy in PANC‐1and BxPC‐3cells treated by CUS alone and combined with GEF.3. Western blot was used to analyze the proteins expressions of EGFR and signaling pathway downstream in PANC‐1and BxPC‐3cells after treatment of CUS alone and combined with GEF.4. RT‐PCR was used to detect the effect of EGFR mRNA in PANC‐1and BxPC‐3cells after CUS treatment.5. Propidiumiodide (PI) staining associated with flow cytometry was used to study CUS induced apoptosis in PANC‐1and BxPC‐3cells in vitro.Results1. The results of SRB assay showed significant time/dose‐dependent proliferation inhibition rate in human pancreatic cancer cell lines PANC‐1and BxPC‐3exposed to CUS. The50%inhibitory concentrations (IC50) of CUS in PANC‐1cells for24h,48h and72h were (12.50±0.012)μmol/L、(0.2678±0.020)μmol/L and (0.0677±0.018) μmol/L, while in BxPC‐3cells were (7.88±0.035)μmol/L、(0.7638±0.026)μmol/L and (0.2935±0.023)μmol/L. 2. The colony forming assay showed that the colony forming rate increased in PANC‐1and BxPC‐3cells exposed to gradually increased CUS, which was92.73%in PANC‐1cells with0.025μmol/L CUS and82.39%in BxPC‐3cells with0.05μmol/L CUS.3. The expression of EGFR proteins were reduced in both of PANC‐1and BxPC‐3cells in vitro exposed to different concentrations of CUS，but the mRNA of EGFR was not significantly influenced. The expression of signaling pathways dowmstream proteins of EGFR were decreased after treatment by CUS.4. Studys after reatment of CUS alone or combined with GEF in PANC‐1and BxPC‐3cells in vitro showed. First, the inhibition rate of useing CUS combined with GEF was higher than useing CUS alone, q>0.85. Second, The combined treatment group could down‐regulated EGFR protein significantly, q>1.15. Third, the colony formation inhibition rate of the combined treatment group was higher than the groups of useing CUS alone, q>1.15.Conclusion1. The proliferation of human pancreatic cancer cell lines PANC‐1and BxPC‐3can be remarkably inhibited by CUS in vitro, showing the time‐dependent and dose‐dependent effect.2. CUS can reduce EGFR protein expression in PANC‐1and BxPC‐3cells in vitro, but no significantly influence on mRNA, which shows it is protein translation stage CUS plays a role in. And the expression of Ras/Raf and PI3K/Akt signaling pathway proteins can be inhibited after CUS treatment.3. CUS combined with GEF shows synergistic effect on cells growth inhibition in PANC‐1and BxPC‐3cells in vitro.