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Muraki, K.

Publications and source records attributed to Muraki, K..

2 recordsLinked to original sources

Identification of Bone Morphogenetic Protein 7 as a Master Regulator of Gastric Cancer-Associated Cachexia

Cachexia is a devastating and multifactorial syndrome characterized by progressive loss of body weight, skeletal muscle wasting, and systemic inflammation, frequently observed in patients with advanced gastric cancer (GC) with peritoneal dissemination. Despite its clinical significance, the molecular mechanisms underlying cancer-associated cachexia remain poorly understood. In this study, comparative transcriptomic analysis using the GEMINI database identified bone morphogenetic protein 7 (BMP7) as a novel candidate cachexia-inducing factor, along with the known cachexia mediators, growth differentiation factor 11 (GDF11) and growth differentiation factor 15 (GDF15). Functional studies demonstrated that BMP7 acts as an upstream regulator that drives cachectic phenotypes by inducing the expression of GDF11 and GDF15. Knockdown of BMP7, GDF11, or GDF15 in the cachexia-inducing GC cell line, MKN45 significantly attenuated weight loss and muscle wasting in vivo. Conversely, overexpression of BMP7 in the non-cachectic GC cell line, NUGC3 induced cachexia and upregulated GDF11 and GDF15 in tumor tissues. Furthermore, clinical analysis revealed that high BMP7 expression in tumor specimens from patients with advanced GC was associated with significantly poorer overall survival. These findings identify BMP7 as a master regulator of cancer-associated cachexia through the induction of GDF11 and GDF15 and suggest its potential as a promising therapeutic target for mitigating cachexia in GC.

cancer biology↗

Telomeric Double Strand Breaks Facilitate Formation of 5’ C-Rich Overhangs in G1 Human Cells

Telomeres are repetitive nucleoprotein complexes that protect chromosomal termini and prevent them from activating an inappropriate DNA damage response (DDR). Here, we characterized the human cellular response to targeted telomeric DSBs in telomerase positive and telomerase-independent alternative lengthening of telomeres (ALT) cells, specifically in G1. Telomeric DSBs in G1 human cells elicited early signatures of a DDR, however, localization of 53BP1, an important regulator of resection at broken ends, was not observed at telomeric break sites. Consistent with this finding and previously reported repression of classical nonhomologous end-joining (c-NHEJ) at telomeres, evidence for c-NHEJ was also lacking. Likewise, no evidence of homologous recombination (HR)-dependent repair of telomeric DSBs in G1 was observed. Rather, and supportive of rapid truncation events, telomeric DSBs in G1 human cells facilitated formation of extensively resected tracks of 5 C-rich telomeric single-stranded (ss)DNA, a previously proposed marker of the recombination dependent ALT pathway. Indeed, induction of telomeric DSBs in human ALT cells also resulted in significant increases in 5 C-rich (ss)telomeric DNA in G1, which rather than RPA, were bound by the complementary telomeric RNA, TERRA. These results suggest that targeting TERRA-mediated protection at damaged telomeres may represent a promising therapeutic strategy, particularly against ALT-positive cancers.

molecular biology↗