The molecular mechanism of luteolin-induced apoptosis is potentially related to inhibition of angiogenesis in human pancreatic carcinoma cells.

Luteolin has been shown to have a strong anticancer effect on various cancer models via programmed cell death (apoptosis). However, the fundamental mechanisms of these effects are still unclear. In the present study, we examined the question of whether or not luteolin can inhibit proliferation of pancreatic carcinoma cells, via apoptosis. We used three human pancreatic carcinoma cell lines, PANC-1, CoLo‑357 and BxPC-3 in our study. In luteolin-treated pancreatic carcinoma cells, typical features of apoptosis were observed. Luteolin increased the expression of the pro-apoptotic protein Bax and decreased the expression of the anti-apoptotic protein Bcl-2, with a concomitant increase in the levels of caspase-3 and cleaved PARP after treatment for 24 h. Luteolin inhibited HUVEC proliferation and vessel growth in CAM in vivo. In addition, the concentration of VEGF in the conditioned medium from human pancreatic carcinoma cells was downregulated by luteolin. Pancreatic carcinoma cells, pretreated with luteolin, could decrease the capillary-like structure formation by HUVEC, which was analyzed by a co-culture system. The abatement of VEGF secretion was related to the inhibition of VEGF mRNA expression, which may be regulated by inhibiting the transcription activity of nuclear transcription factor NF-κB.