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KOBAYASHI, H.

Publications and source records attributed to KOBAYASHI, H..

2 recordsLinked to original sources

eIF4G2-dependent translation restrains pancreatic cancer progression

Pancreatic ductal adenocarcinoma (PDA) is among the most lethal cancers, driven by cellular plasticity that fuels therapeutic resistance and early dissemination. The contribution of translational control to this plasticity remains poorly understood. Through an in vivo CRISPR/Cas9 screen, we identify the non-canonical initiation factor eIF4G2 (DAP5/NAT1) as a translational checkpoint restraining PDA progression. Loss of eIF4G2 accelerated tumor growth, induced poorly differentiated, basal-like histology, and triggered widespread metastasis. Ribosome profiling revealed that eIF4G2 loss does not alter bulk protein synthesis but instead impairs translation of a selective regulon, including tumor suppressors such as PTEN and CREBBP. Functional studies confirmed that PTEN loss was sufficient to drive dedifferentiation but insufficient to promote metastasis, implicating the broader eIF4G2-dependent program, including translational control of transcriptional regulators like CREBBP, in limiting dissemination. Consistently, eIF4G2-deficient tumors exhibited transcriptomic enrichment of programs related to migration and wound healing. Computational inference from human PDA datasets revealed reduced eIF4G2 activity in metastases, aligning with basal-like features and predicting poorer survival. These results support a model in which eIF4G2 maintains epithelial identity and restrains metastatic potential, highlighting selective translation as a determinant of PDA subtype and clinical outcome.

cancer biology↗

Dose-dependent effects of histone methyltransferase NSD2 on site-specific double-strand break repair

Histone modifications are catalyzed and recognized by specific proteins to regulate dynamic DNA metabolism processes. NSD2 is a histone H3 lysine 36 (H3K36)-specific methyltransferase that associates both with various transcription regulators and DNA repair factors. Specifically, it has been implicated in the repair of DNA double-strand breaks (DSBs); however, the role of NSD2 during DSB repair remains enigmatic. Here, we show that NSD2 does not accumulate at DSB sites and that the localization of NSD2 at chromatin is maintained even after DSB formation. Using three different DSB repair reporter systems, which contained the endonuclease site in the active thymidine kinase gene (TK) locus, we demonstrated separate dose-dependent effects of NSD2 on HR, canonical-NHEJ (c-NHEJ), and non-canonical-NHEJ (non-c-NHEJ). Endogenous NSD2 has a role in repressing non-c-NHEJ, without affecting DSB repair efficiency by HR or total NHEJ. Furthermore, overexpression of NSD2 promotes c-NHEJ repair suppressing HR repair. Therefore, we propose that NSD2 has functions in chromatin integrity at the active regions during DSB repair.

cell biology↗