Thymoquinone Selectively Kills Hypoxic Renal Cancer Cells by Suppressing HIF-1α-Mediated Glycolysis

Area of Science:

• Biochemistry
• Molecular Biology
• Oncology

Background:

• Thymoquinone (TQ) is known to inhibit cancer cell angiogenesis and tumor growth.
• The effect of TQ on hypoxia-inducible factor-1α (HIF-1α) in hypoxic cancer cells remains unclear.

Purpose of the Study:

• To investigate whether TQ inhibits HIF-1α expression in hypoxic cancer cells.
• To elucidate the mechanism by which TQ affects HIF-1α.
• To evaluate the anticancer potential of TQ by assessing its impact on cancer cell metabolism and apoptosis.

Main Methods:

• Hypoxia response element (HRE)-luciferase assay for screening natural compounds.
• Western blot analysis to assess HIF-1α protein levels in the presence and absence of proteasome inhibitor MG132.
• Co-immunoprecipitation to study the interaction between HSP90 and HIF-1α.
• Measurement of glucose, lactate, and ATP levels.
• Crystal violet staining and flow cytometry for apoptosis assessment.

Main Results:

• TQ was identified as a novel HIF-1α inhibitor through large-scale screening.
• TQ reduced HIF-1α protein levels via the ubiquitination-proteasome pathway by inhibiting the HSP90-HIF-1α interaction.
• TQ suppressed HIF-1α downstream genes, disturbed anaerobic metabolism, and induced apoptosis in hypoxic cancer cells.

Conclusions:

• Thymoquinone is a potential anticancer agent that targets HIF-1α.
• TQ's mechanism involves promoting HIF-1α degradation and disrupting cancer cell metabolism.
• TQ induces apoptosis in hypoxic cancer cells, highlighting its therapeutic promise.