Elesclomol induces cancer cell apoptosis through oxidative stress
Jessica R Kirshner1, Suqin He, Vishwasenani Balasubramanyam
1Synta Pharmaceuticals Corp., 45 Hartwell Avenue, Lexington, MA 02421, USA.
Abstract:
Elesclomol (formerly STA-4783) is a novel small molecule undergoing clinical evaluation in a pivotal phase III melanoma trial (SYMMETRY). In a phase II randomized, double-blinded, controlled, multi-center trial in 81 patients with stage IV metastatic melanoma, treatment with elesclomol plus paclitaxel showed a statistically significant doubling of progression-free survival time compared with treatment with paclitaxel alone. Although elesclomol displays significant therapeutic activity in the clinic, the mechanism underlying its anticancer activity has not been defined previously. Here, we show that elesclomol induces apoptosis in cancer cells through the induction of oxidative stress. Treatment of cancer cells in vitro with elesclomol resulted in the rapid generation of reactive oxygen species (ROS) and the induction of a transcriptional gene profile characteristic of an oxidative stress response. Inhibition of oxidative stress by the antioxidant N-acetylcysteine blocked the induction of gene transcription by elesclomol. In addition, N-acetylcysteine blocked drug-induced apoptosis, indicating that ROS generation is the primary mechanism responsible for the proapoptotic activity of elesclomol. Excessive ROS production and elevated levels of oxidative stress are critical biochemical alterations that contribute to cancer cell growth. Thus, the induction of oxidative stress by elesclomol exploits this unique characteristic of cancer cells by increasing ROS levels beyond a threshold that triggers cell death.
Insights
Elesclomol induces cancer cell death by increasing oxidative stress. This novel small molecule generates reactive oxygen species (ROS), triggering apoptosis and offering a new therapeutic strategy for melanoma.
Area of Science:
- Oncology
- Molecular Biology
- Biochemistry
Background:
- Elesclomol is a novel small molecule with demonstrated therapeutic activity in melanoma clinical trials.
- The precise mechanism of elesclomol's anticancer action remained undefined prior to this study.
- Cancer cells often exhibit elevated oxidative stress, a characteristic that can be exploited therapeutically.
Purpose of the Study:
- To elucidate the molecular mechanism by which elesclomol exerts its anticancer effects.
- To investigate the role of oxidative stress in elesclomol-induced cancer cell death.
- To determine if reactive oxygen species (ROS) generation is essential for elesclomol's proapoptotic activity.
Main Methods:
- In vitro treatment of cancer cells with elesclomol.
- Measurement of reactive oxygen species (ROS) generation.
- Analysis of gene expression profiles indicative of oxidative stress response.
- Inhibition of oxidative stress using N-acetylcysteine (antioxidant).
- Assessment of drug-induced apoptosis.
Main Results:
- Elesclomol treatment rapidly generated ROS in cancer cells.
- Elesclomol induced a gene expression profile consistent with oxidative stress.
- N-acetylcysteine blocked elesclomol-induced gene transcription and apoptosis.
- ROS generation was identified as the primary driver of elesclomol's proapoptotic effect.
Conclusions:
- Elesclomol induces cancer cell apoptosis through the generation of oxidative stress.
- The drug effectively increases ROS levels beyond a critical threshold, leading to cell death.
- This mechanism of action, by exploiting cancer's inherent oxidative stress, presents a promising therapeutic strategy for melanoma and potentially other cancers.
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