Lupeol triterpene, a novel diet-based microtubule targeting agent: disrupts survivin/cFLIP activation in prostate...

Area of Science:

• Oncology
• Molecular Biology
• Natural Products Chemistry

Background:

• Prostate cancer (CaP) remains a significant health concern, with limited treatment options for advanced stages.
• Lupeol, a triterpene found in fruits and vegetables, has shown preliminary efficacy against androgen-sensitive prostate cancer.
• Understanding Lupeol's mechanism of action is crucial for its therapeutic development.

Purpose of the Study:

• To investigate the efficacy of Lupeol against both androgen-sensitive and androgen-insensitive prostate cancer cells.
• To elucidate the molecular mechanisms underlying Lupeol's anti-cancer effects, focusing on cell cycle regulation and microtubule dynamics.
• To assess Lupeol's safety profile by evaluating its toxicity to normal human prostate epithelial cells (PrEC).

Main Methods:

• Treatment of prostate cancer cell lines (LNCaP and DU145) and normal PrEC with varying doses of Lupeol.
• Analysis of cell cycle progression using flow cytometry and Western blotting to assess protein levels of cyclins, cyclin-dependent kinases (cdks), and CDK inhibitors.
• Investigation of microtubule assembly dynamics and the expression of key regulatory proteins, including alpha-tubulin, beta-tubulin, stathmin, survivin, and cFLIP, using Western blotting and gene expression analysis.

Main Results:

• Lupeol inhibited the growth of both androgen-sensitive and androgen-insensitive prostate cancer cells by inducing G2/M cell cycle arrest.
• Lupeol treatment led to decreased levels of key cell cycle regulators (cyclins, cdk-2) and increased levels of the CDK inhibitor p21.
• Lupeol modulated microtubule components (alpha-tubulin, beta-tubulin), regulatory proteins (stathmin), and downstream targets (survivin, cFLIP), disrupting microtubule assembly and decreasing anti-apoptotic protein levels.
• No toxicity was observed in normal human prostate epithelial cells (PrEC) at effective anti-cancer doses.

Conclusions:

• Lupeol effectively inhibits prostate cancer cell growth through G2/M cell cycle arrest and disruption of microtubule assembly.
• The anti-cancer effects are mediated by simultaneous modulation of stathmin, cFLIP, and survivin pathways.
• Lupeol demonstrates a favorable safety profile, showing no toxicity to normal prostate cells, and holds promise as a potential therapeutic agent for prostate cancer, possibly in combination with other treatments.