HMGB1 knock-down promoting tumor cells viability and arrest pro-apoptotic proteins via Stat3/NFκB in HepG2 cells

Area of Science:

• Molecular Biology
• Cancer Research
• Immunology

Background:

• High mobility group box 1 protein (HMGB1) is a key regulator of cell survival and death pathways, including inflammation and apoptosis.
• HMGB1's role in hepatocellular carcinoma (HCC) is complex, with potential to influence both tumor suppression and promotion.

Purpose of the Study:

• To investigate the effect of silencing HMGB1 on apoptosis and pro-inflammatory protein expression in HepG2 hepatocellular carcinoma cells.
• To elucidate the molecular mechanisms underlying HMGB1's influence on liver cancer cell behavior.

Main Methods:

• HepG2 cells were transfected with small interfering RNA (si-RNA) targeting HMGB1.
• Western blot analysis was used to assess pro-apoptotic (Bax, Bcl2) and pro-inflammatory (p65-NFκB, Cox2) protein expression.
• Flow cytometry with Annexin V FITC and Calcien AM staining evaluated cell apoptosis and proliferation.

Main Results:

• HMGB1 silencing significantly increased HepG2 cell viability and decreased pro-apoptotic protein expression.
• Upregulation of the anti-apoptotic protein Bcl2 was observed, suggesting a role in restricting apoptosis.
• HMGB1 knockdown inhibited Stat3 phosphorylation and affected NFkB p65/Cox2 expression, indicating a link between HMGB1, Stat3, and NFkB signaling.

Conclusions:

• HMGB1 knockdown may suppress apoptosis and enhance HepG2 cell viability through the NFkB/Cox2 and Stat3 signaling pathways.
• These findings suggest HMGB1 as a potential therapeutic target in hepatocellular carcinoma, although its silencing may have paradoxical effects on apoptosis.