Search PubMedSearch

Biomedical subjects

Xiaoyu Hou

Publications and source records attributed to Xiaoyu Hou.

2 recordsLinked to original sources

FMRP promotes gastric cancer progression via m6A-dependent stabilization of DVL2 and activation of the Wnt/PCP-JNK pathway.

BACKGROUND: N6-methyladenosine (m6A) modification has emerged as a critical regulator in gastric cancer progression. Fragile X messenger ribonucleoprotein 1 (FMRP), an RNA-binding protein with tumorigenic potential, remains poorly characterized in gastric cancer. METHODS: FMRP expression in gastric cancer was assessed through bioinformatic analyses and tissue microarray-based immunohistochemistry. Its biological functions were examined through loss-of-function experiments in vitro and in vivo. Mechanistic investigations, including RNA interaction, m6A site mutation, and RNA stability analyses, were performed to identify downstream targets and pathways regulated by FMRP. RESULTS: Bioinformatic analyses and tissue microarray-based immunohistochemistry showed that FMRP was significantly upregulated in gastric cancer tissues. FMRP depletion suppressed tumor growth and metastasis. Subsequently, Dishevelled segment polarity protein 2 (DVL2) was identified as a candidate downstream target of FMRP. DVL2 was also significantly upregulated in gastric cancer tissues, and its expression positively correlated with FMRP expression. Mechanistically, FMRP bound to DVL2 mRNA and enhanced its stability in an m6A-dependent manner. Among the candidate sites tested, mutation of 1271A attenuated FMRP-mediated regulation of DVL2 reporter activity, supporting the involvement of this site. Functionally, FMRP promoted activation of the noncanonical Wnt/planar cell polarity (PCP) signaling pathway and enhanced the proliferative, migratory, and invasive capacities of gastric cancer cells via DVL2. CONCLUSIONS: These results define FMRP as an oncogenic driver in gastric cancer that operates via the DVL2/Wnt/PCP axis. Targeting this pathway may provide a potential therapeutic strategy for gastric cancer.

Stomach Neoplasms

USP10-SIRT6-PARP1 axis drives keratinocyte senescence and skin photoaging under chronic UVA exposure.

Chronic exposure to ultraviolet A (UVA) radiation is the principal environmental driver of skin photoaging, yet the upstream molecular events that commit irradiated keratinocytes to senescence remain poorly understood. Here we show that SIRT6, an NAD+-dependent protein deacetylase with established roles in genome maintenance and organismal longevity, functions as a central gatekeeper of keratinocyte homeostasis under photic stress. Using a chronic UVA irradiation model in mice together with cultured human keratinocytes, we demonstrate that UVA inflicts extensive DNA damage and G2/M cell-cycle arrest, accompanied by selective depletion of SIRT6 among all sirtuin family members. Mechanistically, UVA suppresses the deubiquitinase USP10 at both transcriptional and post-transcriptional levels, thereby licensing ubiquitin-dependent proteasomal degradation of SIRT6. The resulting SIRT6 deficiency unleashes hyperactivation of the DNA-damage sensor PARP1, amplifying genomic injury signaling and driving keratinocytes into irreversible senescence with concomitant elaboration of a broad pro-inflammatory secretory programme encompassing chemokines and cytokines. Pharmacological reactivation of SIRT6 with the selective agonist UBCS039 reverses epidermal hyperplasia, attenuates DNA damage and senescence marker accumulation, and suppresses inflammatory mediator induction both in vivo and in vitro, establishing SIRT6 loss as a causal rather than correlative event. Furthermore, molecular docking and functional validation identify osthole, a plant-derived coumarin from the medicinal herb Cnidium monnieri, as a candidate SIRT6-engaging compound that counteracts UVA-induced senescence and inflammation in keratinocytes. Collectively, these findings define a USP10-SIRT6-PARP1 signaling axis whose disruption underlies cutaneous photoaging and suggest that SIRT6-directed strategies may offer therapeutic benefit against UV-driven tissue degeneration.

Animals