Exploring m6A methylation in skin Cancer: Insights into molecular mechanisms and treatment.

N6-methyladenosine (m6A) is the most common and prevalent internal mRNA modification in eukaryotes. m6A modification is a dynamic and reversible process regulated by methyltransferases, demethylases, and m6A binding proteins. Skin cancers, including melanoma and nonmelanoma skin cancers (NMSCs), are among the most commonly diagnosed cancers worldwide. m6A methylation is involved in the regulation of RNA splicing, translation, degradation, stability, translocation, export, and folding. Aberrant m6A modification participates in the pathophysiological processes of skin cancers and is associated with tumor cell proliferation, invasion, migration, and metastasis during cancer progression. In this review, we provide a comprehensive summary of the biological functions of m6A and the most up-to-date evidence related to m6A RNA modification in skin cancer. We also emphasize the potential clinical applications in the diagnosis and treatment of skin cancers.

Relationship between bullous pemphigoid and malignancy: A Mendelian randomization study.

Bullous pemphigoid (BP) is the most common autoimmune blistering disease, which primarily affects the elderly. However, the relationship between BP and malignancy remains controversial in traditional observational studies. The aim of this study, which included only European populations, was to assess the potential causative link between BP and 13 types of malignant tumors in a two-sample Mendelian randomization (MR) study. BP was not associated with an increased risk of developing 13 types of malignant tumors. This study did not find a causal relationship between BP and malignant tumors. However, further research is warranted to examine the generalizability of this conclusion in non-European populations.

Exosomal lncRNA HOTAIR induces PDL1+ B cells to impede anti-tumor immunity in colorectal cancer.

Regulatory B cells (Bregs) contribute to tumor immunosuppression. However, how B cells acquire their regulatory features in tumors remain unclear. Exosomes are important messengers that transmit tumor information to remodel tumor immunity. Here we revealed that tumor-derived exosomes drive Bregs to suppress anti-tumor immunity by delivering long non-coding RNAs (lncRNAs). HOTAIR was screened by lncRNA profiling in both colorectal cancer (CRC)-derived exosomes and infiltrating B cells. Tumor-derived HOTAIR polarized B cells toward a regulatory feature marked by programmed cell death-ligand 1 (PDL1) in CRC, and induced PDL1+ B cells to suppress CD8+ T cell activity. Exosomal HOTAIR bound to and protected pyruvate kinase M2 (PKM2) against ubiquitination degradation, resulting in STAT3 activation and PDL1 expression. Results from CRC patients showed a positive correlation between exosomal HOTAIR and tumor-infiltrating PDL1+ B cells. These findings reveal how B cells acquire PDL1-dominant regulatory feature in CRC, implying the clinical significance of exosomal therapy targeting HOTAIR.

Alveolar soft tissue sarcoma: a report of 50 cases at a single institution.

BACKGROUND: Alveolar soft-part sarcoma (ASPS) is a rare soft tissue sarcoma subtype, occurring mainly in young people, with poor prognosis. MATERIALS AND METHODS: We conducted a retrospective analysis of localized or metastatic ASPS patients admitted to the First Affiliated Hospital of Zhengzhou University (China) from 2012 to 2020, focusing on treatment and prognosis. RESULTS: The median age at diagnosis was 24 years (range: 1.4-78 years). Women (n = 29, 58%), especially those aged <30 years, dominated this series. The most common metastasis site was lung. Thirty-one (62%) patients developed lung metastasis (localized: n = 9 [18%]; metastatic: n = 22 [44%]). Only a tumor maximum diameter ≥ 5 cm was associated with a high lung metastasis rate (p = 0.039). The mean follow-up time was 37.5 months (1-108 months), and the 5-year overall survival (OS) rate was 84.7%. Univariate analysis indicated that distant metastasis observed at the initial visit and incomplete resection of the primary tumor were associated with poor OS. For localized cases, neither surgery plus radiotherapy (p = 0.486) nor surgery plus chemotherapy (p = 0.536) improved progression-free survival compared to surgery alone. Among the metastatic cases, the disease control rate (PR + SD) was higher for targeted therapy (60%) and combined immunosuppressive therapy (100%) than for conventional cytotoxic chemotherapy (26%). CONCLUSIONS: Postoperative adjuvant radiotherapy and chemotherapy do not provide good local control for patients with localized disease. Although there is no standard treatment strategy for patients with advanced or metastatic disease, they can benefit from targeted therapy and/or immunosuppressive therapy.

Leucine-tRNA-synthase-2-expressing B cells contribute to colorectal cancer immunoevasion.

Immunoregulatory B cells impede antitumor immunity through unknown features and mechanisms. We report the existence of leucine-tRNA-synthase-2 (LARS2)-expressing B cell (LARS B) subset with a transforming growth factor-ß1 (TGF-ß1)-dominant regulatory feature in both mouse and human progressive colorectal cancer (CRC). Of note, LARS B cells exhibited a leucine nutrient preference and displayed active mitochondrial aminoacyl-tRNA biosynthesis. They were located outside the tertiary lymphoid structure and correlated with colorectal hyperplasia and shortened survival in CRC patients. A leucine diet induced LARS B cell generation, whereas LARS B cell deletion by Lars2 gene ablation or leucine blockage repressed CRC immunoevasion. Mechanistically, LARS2 programmed mitochondrial nicotinamide adenine dinucleotide (NAD+) regeneration and oxidative metabolism, thus determining the regulatory feature of LARS B cells in which the NAD-dependent protein deacetylase sirtuin-1 (SIRT1) was involved. We propose a leucine-dieting scheme to inhibit LARS B cells, which is safe and useful for CRC therapy.

TRAF4, a new substrate of SIAH1, participates in chemotherapy resistance of breast cancer cell by counteracting SIAH1-mediated downregulation of ß-catenin.

PURPOSE: TRAF4 plays an important role in the development and progression of breast cancer, but its impact on chemotherapy resistance is as yet, however, poorly understood. METHODS: Western blotting, immunoprecipitation, and immunofluorescence staining were used to identify and verify that TRAF4 was a novel substrate of SIAH1 and prevented SIAH1-mediated ß-catenin degradation. Cell proliferation analysis and Flow cytometry analysis were utilized to detect TRAF4's function on the growth-inhibitory effect of etoposide. Immunohistochemistry was used to detect the expression of TRAF4, SIAH1, and ß-catenin. Statistical analysis was used to analyze the relationships between them with clinical parameters and curative effect of chemotherapy pathologically. RESULTS: Our results suggested that TRAF4 prevents SIAH1-mediated ß-catenin degradation. TRAF4 was a novel substrate of SIAH1 and the TRAF domain of TRAF4 was critical for binding to SIAH1. TRAF4 reduced the growth-inhibitory effect of etoposide via reducing the number of S-phase cells and suppressing cell apoptosis. Concordantly, we found that breast cancer patients with a low-TRAF4 expression benefited most from chemotherapy, who had higher tumor volume reduction rate and better pathological response, while, the high-TRAF4 expression group had lower tumor volume reduction rate and poor pathological response. CONCLUSIONS: TRAF4 was a novel substrate of SIAH1 and prevented SIAH1-mediated ß-catenin degradation, which explains the protective effect of TRAF4 on ß-catenin during cell stress and links TRAF4 to chemotherapy resistance in tumors. These findings implicated a novel pathway for the oncogenic function of TRAF4.