An indolylquinoline derivative activates DNA damage response and apoptosis in human hepatocellular carcinoma cells

Area of Science:

• Oncology
• Molecular Biology
• Biochemistry

Background:

• Hepatocellular carcinoma (liver cancer) is a major global health concern with limited therapeutic options due to treatment resistance.
• Novel anticancer agents are crucial for improving patient outcomes in liver cancer.
• Previous research indicated the efficacy of indolylquinoline EMMQ against lung cancer via mitochondrial impairment.

Purpose of the Study:

• To investigate the anticancer effects of EMMQ on human liver cancer cells.
• To elucidate the molecular mechanisms underlying EMMQ's action in liver cancer.
• To evaluate EMMQ's potential as a therapeutic agent for liver cancer.

Main Methods:

• Treatment of human liver cancer cells and normal cells with EMMQ.
• Assessment of cell viability, apoptosis, DNA damage (p53, γ-H2AX), cell cycle regulators (cyclin D1, CDK2), and mitochondrial function (membrane potential, ROS, cytochrome c release).
• Validation using p53 shRNA to confirm the role of p53 in EMMQ's effects.

Main Results:

• EMMQ significantly inhibited liver cancer cell growth and induced apoptosis, with no effect on normal cells.
• EMMQ triggered DNA damage by activating p53 and γ-H2AX, leading to cell cycle arrest via suppression of cyclin D1 and CDK2.
• EMMQ impaired mitochondrial function, evidenced by reduced membrane potential, increased reactive oxygen species, and cytochrome c release, ultimately promoting apoptosis.
• p53 knockdown abrogated EMMQ's effects, confirming p53 activation as central to DNA damage and apoptosis induction.

Conclusions:

• EMMQ effectively induces apoptosis in liver cancer cells through p53-mediated DNA damage and mitochondrial dysfunction.
• EMMQ demonstrates selective toxicity towards cancer cells, sparing normal cells.
• EMMQ represents a promising therapeutic candidate for treating hepatocellular carcinoma.