TRPML1 and RAS-driven cancers - exploring a link with great therapeutic potential

Area of Science:

• Oncology
• Molecular Biology
• Cell Biology

Background:

• Activating mutations in RAS proto-oncogenes are major drivers of human cancers.
• RAS-driven cancers exhibit significantly increased metabolic demands to support uncontrolled proliferation.
• Enhanced endolysosome and autophagosome biogenesis are critical for RAS-driven cancer cell survival and proliferation.

Purpose of the Study:

• To investigate the role of the endolysosomal cation channel TRPML1 in HRAS-driven cancers.
• To explore the therapeutic potential of targeting TRPML1 in oncogenic RAS-driven malignancies.

Main Methods:

• Analysis of human cancer data to correlate HRAS mutations with MCOLN1 expression.
• Cellular experiments involving TRPML1 inhibition and MCOLN1 knockdown.
• Assessment of cholesterol localization, cell surface HRAS levels, and downstream signaling pathways.

Main Results:

• Human cancers with activating HRAS mutations show elevated MCOLN1 expression, encoding TRPML1.
• Increased TRPML1 activity is required for maintaining plasma membrane cholesterol levels in HRAS-driven cancer cells.
• TRPML1 inhibition or MCOLN1 knockdown causes cholesterol mislocalization, loss of cell surface HRAS, and signaling attenuation.

Conclusions:

• TRPML1 plays a crucial role in regulating cholesterol homeostasis in HRAS-driven cancers.
• Targeting TRPML1 represents a promising novel therapeutic strategy for treating RAS-driven cancers.