Inhibition of Survivin Homodimerization Decreases Neuroblastoma Cell Growth

Area of Science:

• Oncology
• Molecular Biology
• Cancer Therapeutics

Background:

• Increased BIRC5/survivin expression correlates with poor prognosis in neuroblastoma (NB), a common childhood cancer.
• Survivin regulates the mitotic spindle checkpoint, making it a therapeutic target.
• Survivin inhibitors, including transcriptional inhibitors and homodimerization inhibitors, are under investigation.

Purpose of the Study:

• To compare the efficacy of genetic inhibition of survivin transcription versus survivin homodimerization inhibition in neuroblastoma.
• To evaluate novel survivin dimerization inhibitors, S12 and LQZ-7I, against neuroblastoma cells and in preclinical models.

Main Methods:

• Generated Birc5+/-/MYCNtg/+ mice to study genetic inhibition of survivin transcription.
• Tested survivin dimerization inhibitors S12 and LQZ-7I in vitro against NB cells and in vivo using mouse xenotransplant and chick chorioallantoic membrane (CAM) models.
• Assessed effects on cell viability, clonogenicity, anchorage-independent growth, mitotic spindle formation, tumor growth, and hemorrhage.

Main Results:

• Genetic inhibition of survivin transcription did not attenuate NB aggressiveness in mice.
• S12 decreased NB cell viability, clonogenicity, and anchorage-independent growth in vitro and reduced intratumoral hemorrhage in vivo.
• LQZ-7I demonstrated potent in vitro efficacy at lower concentrations, abrogating NB cell growth and distorting mitotic spindles; LQZ-7I reduced tumor size and proliferation in vivo without apparent toxicity.

Conclusions:

• Inhibiting survivin homodimerization, particularly with LQZ-7I, is a more effective strategy for targeting neuroblastoma than inhibiting its transcription.
• LQZ-7I shows significant therapeutic potential for neuroblastoma treatment due to its efficacy in reducing tumor growth and proliferation.
• Further investigation of LQZ-7I as a neuroblastoma therapy is warranted.