Prognosis of
pancreatic cancer is extremely poor, suggesting critical needs for additional drugs to improve disease outcome. In this study, we examined efficacy and associated mechanism of a novel agent bitter melon juice (BMJ) against
pancreatic carcinoma cells both in culture and nude mice. BMJ anticancer efficacy was analyzed in human
pancreatic carcinoma BxPC-3, MiaPaCa-2, AsPC-1 and Capan-2 cells by 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyl tetrazolium
bromide, cell death
enzyme-linked
immunosorbent assay and
annexin/
propidium iodide assays. BMJ effect on apoptosis regulators was assessed by immunoblotting. In vivo BMJ efficacy was evaluated against MiaPaCa-2
tumors in nude mice, and xenograft was analyzed for
biomarkers by immunohistochemistry (IHC). Results showed that BMJ (2-5% v/v) decreases cell viability in all four
pancreatic carcinoma cell lines by inducing strong apoptotic death. At molecular level, BMJ caused
caspases activation, altered expression of Bcl-2 family members and
cytochrome-c release into the cytosol. Additionally, BMJ decreased
survivin and
X-linked inhibitor of apoptosis protein but increased p21, CHOP and phosphorylated
mitogen-activated protein kinases (
extracellular signal-regulated kinase 1/2 and p38) levels. Importantly, BMJ activated
adenosine monophosphate-activated
protein kinase (AMPK), a
biomarker for cellular energy status, and an
AMPK inhibitor (Compound C) reversed BMJ-induced
caspase-3 activation suggesting activated AMPK involvement in BMJ-induced apoptosis. In vivo,
oral administration of lyophilized BMJ (5mg in 100 µl water/day/mouse) for 6 weeks inhibited MiaPaCa-2
tumor xenograft growth by 60% (P < 0.01) without noticeable toxicity in nude mice. IHC analyses of MiaPaCa-2 xenografts showed that BMJ also inhibits proliferation, induces apoptosis and activates AMPK in vivo. Overall, BMJ exerts strong anticancer efficacy against human
pancreatic carcinoma cells, both in vitro and in vivo, suggesting its clinical usefulness.