0

Effective Targeting of RNA Polymerase I in Treatment-Resistant Prostate Cancer

Jin-Yih Low, Paul Sirajuddin, Michael Moubarek, Shreya Agarwal, Apurv Rege, Gunes Guner, Hester Liu, Zhiming Yang, Angelo M De Marzo, Charles Bieberich, Marikki Laiho

Prostate. 2019 Dec;79(16):1837-1851.

PMID: 31524299

Abstract:

Background:
Advanced prostate cancers depend on protein synthesis for continued survival and accelerated rates of metabolism for growth. RNA polymerase I (Pol I) is the enzyme responsible for ribosomal RNA (rRNA) transcription and a rate-limiting step for ribosome biogenesis. We have shown using a specific and sensitive RNA probe for the 45S rRNA precursor that rRNA synthesis is increased in prostate adenocarcinoma compared to nonmalignant epithelium. We have introduced a first-in-class Pol I inhibitor, BMH-21, that targets cancer cells of multiple origins, and holds potential for clinical translation.
Methods:
The effect of BMH-21 was tested in prostate cancer cell lines and in prostate cancer xenograft and mouse genetic models.
Results:
We show that BMH-21 inhibits Pol I transcription in metastatic, castration-resistant, and enzalutamide treatment-resistant prostate cancer cell lines. The genetic abrogation of Pol I effectively blocks the growth of prostate cancer cells. Silencing of p53, a pathway activated downstream of Pol I, does not diminish this effect. We find that BMH-21 significantly inhibited tumor growth and reduced the Ki67 proliferation index in an enzalutamide-resistant xenograft tumor model. A decrease in 45S rRNA synthesis demonstrated on-target activity. Furthermore, the Pol I inhibitor significantly inhibited tumor growth and pathology in an aggressive genetically modified Hoxb13-MYC|Hoxb13-Cre|Ptenfl/fl (BMPC) mouse prostate cancer model.
Conclusion:
Taken together, BMH-21 is a novel promising molecule for the treatment of castration-resistant prostate cancer.

Chemicals Related in the Paper:

Catalog Number Product Name Structure CAS Number Price
AP896705161 BMH-21 BMH-21 896705-16-1 Price
qrcode