Gallic acid suppresses colon cancer proliferation by inhibiting SRC and EGFR phosphorylation

Area of Science:

• Oncology
• Molecular Biology
• Pharmacology

Background:

• Colon cancer remains a leading cause of cancer-related mortality worldwide.
• Targeting key signaling pathways like SRC and EGFR is crucial for effective cancer therapy.
• Gallic acid (GA), a natural polyphenol, has shown potential anti-cancer properties.

Purpose of the Study:

• To investigate the effects of gallic acid (GA) on colon cancer cell proliferation and apoptosis.
• To elucidate the mechanism of GA action, focusing on SRC and EGFR phosphorylation.
• To evaluate GA's efficacy in a preclinical colon cancer model.

Main Methods:

• HCT116 and HT29 colon cancer cells were treated with varying concentrations of GA.
• Cell proliferation and apoptosis were assessed using clone formation and flow cytometry.
• Protein expression and phosphorylation levels (SRC, EGFR, AKT, STAT3) were analyzed via Western blotting and immunofluorescence.
• Specific SRC and EGFR inhibitors (PP2, gefitinib) were used to confirm mechanisms.
• In vivo efficacy was tested using a xenograft tumor model.

Main Results:

• GA significantly inhibited colon cancer cell proliferation and induced apoptosis, evidenced by increased cleaved caspase-3/9 levels.
• GA treatment led to decreased phosphorylation of SRC, EGFR, AKT, and STAT3.
• Inhibition of SRC and EGFR pathways by GA was confirmed using specific inhibitors.
• In vivo studies showed GA suppressed tumor growth and promoted apoptosis.

Conclusions:

• Gallic acid effectively suppresses colon cancer proliferation and induces apoptosis.
• GA exerts its anti-cancer effects by inhibiting SRC and EGFR phosphorylation, subsequently downregulating AKT and STAT3 signaling.
• GA demonstrates therapeutic potential for colon cancer treatment.