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Jianfeng Shen

Publications and source records attributed to Jianfeng Shen.

2 recordsLinked to original sources

ATR-dependent phosphorylation of the histone acetyltransferase HBO1 suppresses chromatin binding and promotes replication stress responses.

Mounting evidence has shown that histone acetyltransferase binding to ORC1 (HBO1) serves as an oncoprotein, warranting the use of the small molecule inhibitor WM-3835 for cancer therapy. However, HBO1 is ubiquitously expressed in both tumor and normal tissues, with potential to increase the risk of systemic toxicity. This unmet need highlights the importance of identifying suitable biomarkers to predict the sensitivity to HBO1 inhibitor. Here, we show that ATR, a key regulator of DNA replication stress, is a novel interacting partner of HBO1. In addition, we reveal a regulatory function of HBO1 in DNA replication stress responses, in an ATR-dependent manner. Mechanistically, ATR mediated HBO1 Ser50/53 phosphorylation interferes with the genomic binding of HBO1 and regulates gene expression. Notably, overexpression of HBO1 mutated at the ATR phosphorylation site (S50/53A) dampens the expression of DNA repair related genes and suppresses tumor colony formation, consistent with the observations of WM-3835 treatment. Inhibition of ATR significantly antagonized the sensitivity to WM-3835 treatment. Collectively, our findings uncovered a previously unidentified role of HBO1 in the regulation of replication stress and discovered ATR as a potential biomarker for WM-3835 treatment.

ATR

Repression of PRMT activities sensitize homologous recombination-proficient ovarian and breast cancer cells to PARP inhibitor treatment.

Therapeutic epigenetic modulation is currently being evaluated in the clinic to sensitize homologous recombination (HR)-proficient tumors to PARP inhibitors. To broaden its clinical applicability and identify more effective combination strategies, we conducted a drug screen combining PARP inhibitors with 74 well-characterized epigenetic modulators targeting five major classes of epigenetic enzymes. Notably, both type I PRMT inhibitors and PRMT5 inhibitors scored highly in combination efficacy and clinical prioritization. PRMT inhibition significantly enhanced PARP inhibitor-induced DNA damage in HR-proficient ovarian and breast cancer cells. Mechanistically, PRMT suppression downregulates DNA damage repair genes and BRCAness-associated pathways, while also modulating intrinsic innate immune responses within cancer cells. Integrative analysis of large-scale genomic and functional datasets from TCGA and DepMap further supports PRMT1, PRMT4, and PRMT5 as promising therapeutic targets in oncology. Importantly, dual inhibition of PRMT1 and PRMT5 synergistically sensitizes tumors to PARP inhibitors. Collectively, our findings provide strong rationale for the clinical development of PRMT and PARP inhibitor combinations in HR-proficient ovarian and breast cancers.

Journal Article