American Association for Cancer Research
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Figure S2, E from Diffuse Intrinsic Pontine Glioma Cells Are Vulnerable to Mitotic Abnormalities Associated with BMI-1 Modulation

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journal contribution
posted on 2023-04-03, 17:23 authored by Shiva Senthil Kumar, Satarupa Sengupta, Xiaoting Zhu, Deepak Kumar Mishra, Timothy Phoenix, Lisa Dyer, Christine Fuller, Charles B. Stevenson, Mariko DeWire, Maryam Fouladi, Rachid Drissi

E, Representative IF-FISH images of metaphase spreads with centromere probe (red) and γH2AX (green) in CCHMC-DIPG-1 and SU-DIPG-IV cells treated with PTC596 (60 nM and 30 nM respectively) for 48 hrs. DAPI (blue) indicates chromosomes. White arrowheads indicate chromosomes with PSCS.


CancerFree KIDS Pediatric Cancer Research Alliance

Pray Hope and Believe Foundation

PTC Therapeutics

Cure Starts Now Foundation

Division of Oncology, and the Brain Tumor Center



Diffuse intrinsic pontine glioma (DIPG) is a poor-prognosis pediatric brain tumor with a median survival of less than 1 year. No effective therapy is currently available, and no therapeutic advances have been made in several decades. We have previously identified BMI-1 as a potential therapeutic target in DIPG and have shown that BMI-1 is highly expressed in DIPG tumors regardless of histone 3 subtype. In the present study, we show that the modulation of BMI-1 leads to DNA damage, M phase cell-cycle arrest, chromosome scattering, and cell death. Interestingly, EZH2 inhibition did not alter these effects. Furthermore, modulation of BMI-1 sensitizes DIPG patient-derived stem-like cells to ionizing radiation (IR). Treatment of DIPG stem-like cells with PTC596, a BMI-1 modulator, and IR impairs the kinetics of DNA damage response (DDR). Both DDR foci formation and resolution were delayed, resulting in further reduction in cell viability compared with either treatment alone. In vivo, treatment of mice bearing DIPG xenografts with PTC596 leads to decreased tumor volume and growth kinetics, increased intratumoral apoptosis, and sustained animal survival benefit. Gene expression analysis indicates that BMI-1 expression correlates positively with DIPG stemness and BMI-1 signature. At the single-cell level, the analysis reveals that BMI-1 pathway is upregulated in undifferentiated cells and positively correlates with stemness in DIPG tumors. Together, our findings indicate that BMI-1 modulation is associated with mitotic abnormalities, impaired DDR, and cell death, supporting the combination of BMI-1 modulation and radiation as a promising novel therapy for children with DIPG.

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