Ethacrynic Oxadiazole 6u Induces Apoptosis by Targeting mTOR/c-Flip Axis and Noxa in Lymphoma Cells
Yafei Kuang1, Shuoyan Feng1, Jinxiao Sun2
1Department of Pharmacology, Liaoning Key Lab of Targeting Drugs for Hematological Malignancies, Shenyang Pharmaceutical University, Shenyang, Liaoning, 110016, China.
Background:
Evasion of apoptosis is a major cause of therapy failure in lymphoma. We studied a covalent compound 6u with an α, β-saturated carbonyl group derived from the diuretic drug ethacrynic acid to induce apoptosis of lymphoma cells by targeting antiapoptotic proteins.
Results:
We found that 6u induces apoptosis in 4 lymphoma cell lines, Daudi, Romas, Jeko-1 and Jurkat, accompanied by down-regulation of c-Flip and Mcl-1, as well as upregulation of Noxa. The down-regulation of Mcl-1 relies on Noxa induction and that the down-regulation of c-Flip is mediated by inhibiting protein synthesis pathway through covalent binding to mTOR complexes. Overexpression of c-Flip and silencing Noxa attenuate 6u-induced apoptosis. 6u modified with the saturated carbonyl structure loses the mTOR inhibition and apoptosis induction abilities. 6u exhibits potent anti-lymphoma effects in mantle cell lymphoma Jeko-1 xenografts without causing toxicity.
Conclusion:
6u functions as an apoptosis inducer through the α, β-saturated carbonyl group to decrease c-Flip and to induce Noxa. 6u represents a new type of covalent agent for targeting lymphoma by inducing apoptosis.
Insights
A new covalent compound, 6u, effectively induces apoptosis in lymphoma cells by targeting key proteins. This novel agent shows potent anti-lymphoma effects without toxicity in preclinical models.
Area of Science:
- Oncology
- Molecular Biology
- Drug Discovery
Background:
- Apoptosis evasion is a primary driver of lymphoma treatment failure.
- Targeting anti-apoptotic proteins is a strategy to overcome therapeutic resistance.
- The covalent compound 6u, derived from ethacrynic acid, was investigated for its apoptotic potential in lymphoma.
Purpose of the Study:
- To investigate the mechanism by which compound 6u induces apoptosis in lymphoma cells.
- To identify the specific anti-apoptotic proteins targeted by 6u.
- To evaluate the therapeutic efficacy and safety of 6u in preclinical lymphoma models.
Main Methods:
- Treatment of lymphoma cell lines (Daudi, Romas, Jeko-1, Jurkat) with compound 6u.
- Analysis of apoptosis markers, including c-Flip, Mcl-1, and Noxa.
- Investigation of protein synthesis pathways and mammalian target of rapamycin (mTOR) complex binding.
- Assessment of 6u efficacy in mantle cell lymphoma xenografts.
Main Results:
- Compound 6u induced apoptosis in four lymphoma cell lines.
- Apoptosis was associated with decreased c-Flip and Mcl-1, and increased Noxa.
- 6u inhibited protein synthesis via covalent binding to mTOR complexes, leading to c-Flip downregulation.
- Mcl-1 downregulation was dependent on Noxa induction.
- Overexpression of c-Flip or Noxa silencing reduced 6u-induced apoptosis.
- A modified 6u lacking the saturated carbonyl group lost its apoptosis-inducing and mTOR inhibitory functions.
- 6u demonstrated significant anti-lymphoma activity in vivo without observable toxicity.
Conclusions:
- Compound 6u acts as an apoptosis inducer in lymphoma cells through its α, β-saturated carbonyl group.
- 6u decreases c-Flip and induces Noxa, leading to lymphoma cell death.
- 6u represents a novel class of covalent agents for lymphoma therapy by inducing apoptosis.
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