Ascorbate induces apoptosis in melanoma cells by suppressing Clusterin expression

Area of Science:

• Oncology
• Epigenetics
• Biochemistry

Background:

• Pharmacological ascorbate has been explored for cancer treatment, but its efficacy is limited by similar effective concentrations (EC50) in healthy and cancerous cells.
• Loss of 5-hydroxymethylcytosine (5hmC) is a key epigenetic alteration in cancer.
• Ascorbate acts as a cofactor for TET enzymes, promoting 5hmC generation.

Purpose of the Study:

• To investigate the therapeutic potential of physiological ascorbate concentrations in melanoma.
• To elucidate the molecular mechanisms underlying ascorbate-induced apoptosis in melanoma cells.

Main Methods:

• Treatment of A2058 melanoma cells with 100 μM ascorbate.
• RNA-sequencing (RNA-seq) analysis to assess gene expression changes.
• Validation of Clusterin (CLU) gene expression at transcript and protein levels.
• Analysis of apoptosis-related protein expression and subcellular localization.

Main Results:

• 100 μM ascorbate induced apoptosis in A2058 melanoma cells.
• Ascorbate treatment downregulated Clusterin (CLU) gene expression at both transcript and protein levels.
• Changes in CLU subcellular localization, Bax and caspases activation, and cytochrome c release were observed.

Conclusions:

• Physiological ascorbate concentrations can induce apoptosis in melanoma cells.
• Downregulation of CLU and associated apoptotic pathway activation are key mechanisms.
• This study highlights a potential therapeutic strategy using physiological ascorbate to enhance melanoma apoptosis.