- 作者: Aishwarya Gondane, Samuel Girmay, Alma Helevä, Satu Pallasaho, Massimo Loda & Harri M. Itkonen
- 作者服務機構: 1.Department of Biochemistry and Developmental Biology, Faculty of Medicine, University of Helsinki, Helsinki, Finland 2.Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York-Presbyterian Hospital, New York, NY, USA 3.The Broad Institute of Harvard and MIT, Cambridge, MA, USA 4.The New York Genome Center, New York, NY, USA
- 中文摘要:
- 英文摘要:
Background: Transcription, metabolism and DNA damage response are tightly regulated to preserve the genomic
integrity, and O-GlcNAc transferase (OGT) is positioned to connect the three. Prostate cancer is the most common
cancer in men, and androgen-ablation therapy halts disease progression. However, a signifcant number of prostate
cancer patients develop resistance against anti-androgens, and this incurable disease is termed castration-resistant
prostate cancer (CRPC). We have shown that combined inhibition of OGT and the transcription elongation kinase
CDK9 induce CRPC-selective anti-proliferative efects. Here, we explain the functional basis for these combinatorial
efects.
Methods: We used comprehensive mass spectrometry profling of short-term CDK9 inhibitor efects on O-GlcNAcylated proteins in an isogenic cell line system that models transition from PC to CRPC. In addition, we used both
ChIP-seq and RNA-seq profling, and pulldown experiments in multiple CRPC models. Finally, we validated our fndings in prostate cancer patient samples.
Results: Inhibition of CDK9 results in an OGT-dependent remodeling of the proteome in prostate cancer cells. More
specifcally, the activity of the DNA damage repair protein MRE11 is regulated in response to CDK9 inhibition in an
OGT-dependent manner. MRE11 is enriched at the O-GlcNAc-marked loci. CDK9 inhibition does not decrease the
expression of mRNAs whose genes are bound by both O-GlcNAc and MRE11. Combined inhibition of CDK9 and
OGT or MRE11 further decreases RNA polymerase II activity, induces DNA damage signaling, and blocks the survival
of prostate cancer cells. These efects are seen in CRPC cells but not in normal prostate cells. Mechanistically, OGT
activity is required for MRE11 chromatin-loading in cells treated with CDK9 inhibitor. Finally, we show that MRE11
and O-GlcNAc are enriched at the prostate cancer-specifc small nucleotide polymorphic sites, and the loss of MRE11
activity results in a hyper-mutator phenotype in patient tumors.
Conclusions: Both OGT and MRE11 are essential for the repair of CDK9 inhibitor-induced DNA damage. Our study
raises the possibility of targeting CDK9 to elicit DNA damage in CRPC setting as an adjuvant to other treatments - 中文關鍵字:
- 英文關鍵字: : DNA damage, Cyclin-dependent kinase 9, O-GlcNAc transferase, MRE11, Castration-resistant prostate cancer