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Primary WWOX phosphorylation and JNK activation during etoposide induces cytotoxicity in HEK293 cells
M Jamshidiha1, P Habibollahi, S N Ostad
1Department of Pharmacology-Toxicology, Faculty of Pharmacy.
Background And The Purpose Of The Study:
Etoposide is an antineoplastic agent used in multiple cancers. It is known that etoposide induce cell death via interaction with topoisomerase II; however, the etopoisde cellular response is poorly understood. Upon etoposide induced DNA damage, many stress signaling pathways including JNK are activated. In response to DNA damage, it has been shown that WWOX, a recently introduced tumor suppressor, can be activated. In this study the activation of WWOX and JNK and their interaction following etoposide treatment were evaluated.
Materials And Methods:
HEK293 cells treated with etoposide were lysed in a time course manner. The whole cell lysates were used to evaluate JNK and WWOX activation pattern using Phospho specific antibodies on western blots. The viability of cells treated with etoposide, JNK specific inhibitor and their combination was examined using MTT assay.
Results:
Findings of this study indicate that WWOX and JNK are activated in a simultaneous way in response to DNA damage. Moreover, JNK inhibition enhances etoposide induced cytotoxicity in HEK293.
Conclusion:
Taken together, our results indicate that etoposide induces cytotoxicity and WWOX phosphorylation and the cytotoxicty is augmented by blocking JNK pathway.
Insights
Etoposide triggers cancer cell death by activating WWOX and JNK pathways. Blocking JNK enhances etoposide
Area of Science:
- Cancer Biology
- Molecular Oncology
- Cellular Stress Response
Background:
- Etoposide is an antineoplastic drug targeting topoisomerase II.
- Cellular response to etoposide-induced DNA damage involves stress pathways like JNK.
- WWOX, a tumor suppressor, is activated by DNA damage.
Purpose of the Study:
- To investigate the activation patterns of WWOX and JNK upon etoposide treatment.
- To explore the interaction between WWOX and JNK in response to etoposide.
- To determine the effect of JNK inhibition on etoposide-induced cytotoxicity.
Main Methods:
- HEK293 cells were treated with etoposide in a time-course experiment.
- Western blotting with phospho-specific antibodies assessed WWOX and JNK activation.
- MTT assay evaluated cell viability under etoposide and JNK inhibitor treatment.
Main Results:
- WWOX and JNK activation occurred simultaneously following DNA damage.
- Inhibition of JNK signaling potentiated etoposide-induced cytotoxicity in HEK293 cells.
Conclusions:
- Etoposide induces cytotoxicity and WWOX phosphorylation.
- Blocking the JNK pathway enhances etoposide's cytotoxic effects.
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