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Biomedical subjects

Yi Wu

Publications and source records attributed to Yi Wu.

2 recordsLinked to original sources

Enhancer-mediated DDIT4 activation by SMYD2-dependent H3K4me1 promotes pazopanib resistance in clear cell renal cell carcinoma.

BACKGROUND: The progression and resistance to targeted therapy, including pazopanib, frequently lead to poor prognosis in clear cell renal cell carcinoma (ccRCC) patients. However, the underlying molecular mechanisms of these processes remain unclear. METHODS: In this study, we first performed RNA-seq to identify genes that were differentially expressed in both SMYD2-knockdown and pazopanib-resistant cells, indicating their potential role in SMYD2-mediated drug resistance. We analyzed TCGA-KIRC data and 150 patient samples to identify the relationship between SMYD2 and DDIT4 expression levels, as well as the prognostic significance of DDIT4. In vitro functional assays and murine models were applied to evaluate the effects of SMYD2 and DDIT4 on tumor growth and on pazopanib resistance. CUT&Tag and chromosome conformation capture (4 C) assays were applied to identify enhancers associated with SMYD2-mediated regulation of DDIT4, while the JASPAR database was utilized to predict transcription factors involved in the enhancer regulation. CRISPR-mediated enhancer deletion and ChIP-qPCR were subsequently performed to validate the regulatory roles of the identified enhancer and the transcription factor SPI1 in DDIT4 expression. RESULTS: Our study revealed that the expression level of DDIT4 is positively correlated with SMYD2. DDIT4 is highly expressed in renal cell carcinoma and is associated with poorer survival outcomes. Further research revealed that SMYD2 regulates H3K4me1 in a DDIT4 distal enhancer (chr10:72830412-72830891), promoting the recruitment of the transcription factor SPI1, thereby activating DDIT4 expression. We found that DDIT4 promotes the proliferation, metastasis, and pazopanib resistance of ccRCC, and DDIT4 knockdown enhances drug sensitivity in both in vitro and in vivo experiments. Furthermore, the SMYD2-DDIT4 axis activates the downstream STAT3 signaling pathway, thereby promoting tumor progression. In addition, DDIT4-related prognostic features showed potential associations with patient survival and predicted drug sensitivity in computational analyses. CONCLUSIONS: Our study identifies a previously unrecognized SMYD2-enhancer-DDIT4 regulatory axis, which promotes tumor progression and pazopanib resistance in ccRCC. These findings may provide potential therapeutic implications to overcome pazopanib resistance and improve treatment outcomes in ccRCC by targeting the SMYD2-enhancer-DDIT4 axis.

Carcinoma, Renal Cell

A pan-cancer single-cell atlas uncovers the role of sex hormones and chromosomes in sex-divergent reprogramming of the tumor microenvironment.

BACKGROUND: Sex bias is pervasive in tumors; however, how sex chromosomes and hormone-responsive signaling shape the tumor microenvironment (TME) remains insufficiently characterized. Considering the critical impact of the TME on tumor progression and response to immunotherapy, a pan-cancer investigation of sex-specific and cancer-context-dependent TME features is warranted. METHOD: Based on stringent inclusion criteria, we constructed a high-resolution pan-cancer single-cell sequencing atlas by integrating 31 publicly available single-cell RNA-seq datasets, comprising a total of 1,831,436 cells by integrating 468 samples from eight types of non-sex-specific solid tumors (282 males and 186 females). After correcting for batch effects, we identified major and minor cellular subsets. Multiple computational approaches were applied to investigate sex-associated differences in cellular composition, gene expression, pathway activity, malignant cell states and intercellular communication. RESULTS: We systematically compared sex-specific TME features across eight common solid malignancies. Male-biased CD8+ T cell exhaustion emerged as a recurrent but non-uniform feature, with its magnitude varying across cancer types and being modified by tissue-specific contexts. This pattern was associated with androgen-response signature scores and expression-based loss of the Y chromosome (LOY) scores. M2-like macrophage polarization showed a more cancer-type-dependent pattern; although female-biased enrichment was observed in selected malignancies, it did not represent a uniform pan-cancer feature. Expression-based X chromosome inactivation (XCI)/XCI escape-related programs, estrogen-response signature scores and stromal components, including fibroblasts and endothelial cells, were associated with macrophage and immune-regulatory states in specific tumor contexts. Tumor cells of male origin displayed higher genomic instability and more aggressive phenotypes, with androgen-response signatures and LOY contributing to the development of a male biased malignant state. Furthermore, expression-based LOY scores in malignant cells were associated with CD8+ T cell exhaustion based on transcriptomic proxies. CONCLUSION: Our study uncovers extensive but heterogeneous sex-specific differences in the TME across multiple cancer types. We propose a regulatory framework linking sex chromosomes, hormone-responsive signaling and TME interactions, which is consistent with recurrent male-biased CD8⁺ T cell exhaustion and context-dependent M2-like macrophage polarization. Importantly, the magnitude and, in some cancers, the direction of these sex-biased features are modified by tissue-specific contexts. These findings underscore the need to include sex chromosome and hormone status as essential biological variables in studies of the tumor microenvironment and the design of immunotherapies.

Tumor Microenvironment