Abstract
Pancreatic cancer (PC) remains the fourth leading cause of cancer death with an unacceptable survival that has remained relatively unchanged over the past 25 years. The presence of occult or clinical metastases at the time of diagnosis together with the lack of effective chemotherapies pose a dire need for designing new and targeted therapeutic deliverables that favors the clinical outcome. Herein, we investigated the anti-tumorigenic potential of polyphenols from five different brown-algae in human PC cells (MiaPaCa-2, Panc-1, BXPC-3 and Panc-3.27). Total anti-oxidant capacity (TAC) analysis on stepwise polyphenol separations with increasing polarity (Hexane-DCM-EA-methanol) identified high levels of TAC in DCM and EA extractions across all seaweeds assessed. All DCM and EA separated polyphenols induced a dose-dependent and sustained (time-independent) inhibition of cell proliferation and viability. Further, these polyphenols profoundly enhanced DNA damage (acridine orange/Ethidium bromide staining and DNA fragmentation) in all the cell lines investigated. More importantly, luciferase reporter assay revealed a significant inhibition of NFκB transcription in cells treated with polyphenols. Interestingly, QPCR analysis identified a differential yet definite regulation of pro-tumorigenic EGFR, VEGFA, AKT, hTERT, kRas, Bcl2, FGFα and PDGFα transcription in cells treated with DCM and EA polyphenols. Immunoblotting validates the inhibitory potential of seaweed polyphenols in EGFR phosphorylation, kRas, AurKβ and Stat3. Together, these data suggest that intermediate polarity based fractions of seaweed polyphenols may significantly potentiate tumor cell killing and may serve as potential drug deliverable for PC cure. More Studies dissecting out the active constituents in potent fractions, mechanisms of action and synergism, if any, are warranted and are currently in process.