Hypermethylation of specific gene promoters is an important mechanism of carcinogenesis. A high frequency of promoter methylation of PAX1 and ZNF582 genes has been detected in cervical cancer. In the present study, we investigated the methylation status of PAX1 and ZNF582 genes in esophageal squamous cell carcinoma (ESCC) tissues. Tumor and paracancerous tissues were obtained from 14 ESCC patients. Genomic DNA was extracted from both tumor and paracancerous tissues, and the concentration of DNA were determined. DNA methylation analysis of PAX1 and ZNF582 genes was carried out using quantitative methylation-specific PCR. To assess the diagnostic performance of the two methylated genes for cancer detection, receiver operating characteristic (ROC) curves were generated. Sensitivities and specificities were tested at cut-offs obtained from the ROC curves. The methylation levels of both PAX1 and ZNF582 genes were significantly higher in tumor tissues compared to non-tumor paracancerous tissues. The methylation rates of PAX1 and ZNF582 in ESCC tumor and paracancerous tissues were 100% and 21.4% (p = 0.006), 85.7% and 0% (p < 0.001), respectively. The sensitivities and specificities of PAX1 and ZNF582 methylation for the detection of cancer were 100% and 85.7%, and 78.6% and 100%, respectively. The DNA methylation levels and frequencies of PAX1 and ZNF582 genes were markedly higher in ESCC tumor tissues compared to those in paracancerous tissues. Moreover, the conclusions were verified by using The Cancer Genome Atlas (TCGA) datasets. DNA methylation status of these two genes showed a relatively good sensitivity and specificity for the detection of ESCC tumors. This data suggests that DNA methylation testing holds a great promise for ESCC screening and warrants further prospective population-based studies.

Deficient mismatch repair (dMMR) in gastric cancer is associated with a high tumor mutation burden (TMB) and increased neoantigen load, which may enhance sensitivity to immunotherapy. Nevertheless, heterogeneous responses among patients with dMMR suggest complex tumor immune microenvironment (TIME) regulation. The present study aimed to integrate a case of dMMR gastric cancer with multi‑cohort bioinformatic analyses to assess TIME determinants of immunotherapy outcomes, focusing on hematological immune cell subsets. Pre‑ and post‑immunotherapy TIME changes were evaluated in a patient with dMMR gastric cancer using immunohistochemistry analysis [CD8⁺, CD4⁺, forkhead box P3 (FoxP3)⁺ regulatory T cells (Tregs), M1/M2 macrophages and programmed death‑ligand 1 (PD‑L1)]. Moreover, bioinformatics analyses assessed microsatellite instability (MSI) status, immune checkpoints [cytotoxic T‑lymphocyte‑associated protein 4 (CTLA4), CD274 and programmed cell death protein 1 (PDCD1)], TMB and TIME cell infiltration across The Cancer Genome Atlas (TCGA)‑stomach adenocarcinoma (STAD; n=383), Kim (n=45), Peking University Cancer Hospital (n=31) and Esophagogastric Cancer‑Memorial Sloan Kettering‑2017 (EGC‑MSK‑2017; n=28) cohorts using CIBERSORT (LM22) and R‑based statistical approaches. The case report demonstrated that, prior to treatment, the tumor was deemed ‘immune cold’, characterized by low levels of CD8⁺ T cells, M1 macrophages and Tregs. Post‑treatment, total T cell infiltration increased, driven primarily by CD4⁺ T cells, while CD8⁺ T cell levels remained low. FoxP3⁺ T cell density (0.18 cells/mm²) indicated potential immune suppression; B cell infiltration (CD20⁺, 17.07 cells/mm²) did not markedly increase, with no tertiary lymphoid structures (TLS) detected. Moreover, bioinformatics cross‑cohort analyses revealed favorable immunological features in microsatellite instability (MSI)‑high (MSI‑H) gastric cancer compared with in MSI‑low (MSI‑L)/microsatellite stability (MSS) gastric cancer. In TCGA‑STAD dataset, MSI‑H tumors had significantly higher TMB, neoantigen load, infiltration of memory‑activated CD4⁺ T cells, activated natural killer (NK) cells, mast cells, M1 macrophages and immune checkpoint markers (CTLA4, CD274 and PDCD1; all P<0.05); CD8⁺ T cells differed significantly between MSI‑H and MSI‑L (P<0.05), but not between MSI‑H and MSS cancer. MSI‑H was associated with a higher TMB in the Kim and EGC‑MSK‑2017 cohorts, a higher immunotherapy response rate in the Kim cohort (P0.05). In conclusion, the results demonstrated that in dMMR/MSI‑H tumors (which typically exhibit high TMB and neoantigen load), a TIME characterized by low CD8⁺ T cells, high Tregs, absent TLS and low PD‑L1, could be indicative of immunotherapy resistance. Cross‑cohort analysis further revealed that despite favorable immunological features (higher TMB, neoantigen load, memory‑activated CD4⁺ T cells, activated NK cells, mast cells, M1 macrophages and immune checkpoint expression), MSI‑H gastric cancers have heterogeneous immunotherapy outcomes. Collectively, dMMR/MSI‑H status alone is insufficient for outcome prediction, highlighting the need for individualized TIME evaluation in patients with gastric cancer receiving immunotherapy.

Apocrine carcinoma associated with Paget’s disease is a rare malignancy that typically manifests in elderly individuals, predominantly affecting the geriatric population. It commonly arises in regions rich in apocrine glands and often exhibits an insidious onset, potentially requiring several years to be diagnosed. An 80-year-old male was simultaneously diagnosed with scrotal apocrine carcinoma (showing Paget changes) and early-stage gastric cancer. Whole-genome exome sequencing confirmed these as independent malignancies with minimal genetic overlap, indicating that they were two primary tumors. The patient initially underwent successful surgery but experienced recurrence and metastasis. Treatment with capecitabine and paclitaxel showed promising responses, highlighting similarities between breast and apocrine carcinomas. Challenges were noted in the use of genetic testing and drug susceptibility assessments for treatment guidance. Notably, HER-2 expression in metastatic lesions, a trait of apocrine carcinoma, has remained unexplored due to negative HER-2 FISH results and a lack of available targeted therapies in China. Elderly patients often exhibit a lesser degree of aggressiveness toward treatment following a diagnosis of malignant tumors. It is imperative to carefully consider how to strike a balance between effective treatment and maintaining a satisfactory quality of life for these patients. This case underscores the complexity of treating coexisting rare cancers in older adults and emphasizes the need for personalized treatments and continued innovation in cancer therapy. The insights gained offer significant value in understanding and managing such rare cancer cases.

Increasing reports have highlighted the roles of tRNA-derived fragments (tRFs) in the pathological processes of cancers. However, the biogenesis, precise functions, and underlying mechanisms of tRFs in non-small-cell lung cancer (NSCLC) remain largely unexplored. Dysregulated tRFs in NSCLC were identified by tRF & tiRNA sequencing, qRT-PCR, and fluorescence in situ hybridization (FISH) assays. The biological roles of tRF in cell malignant phenotypes and aerobic glycolysis were determined by functional experiments in vitro and in vivo. The clinical significance of tRF was assessed in human NSCLC samples using FISH and ¹⁸F-FDG PET/CT scan. The underlying mechanisms of tRF were explored by RNA sequencing, dual-luciferase assay, polysome profiling, Western blotting, qRT-PCR, and rescue experiments. We identified a novel tRF, AS-tDR-008,272, which was upregulated in NSCLC tumor tissues, plasma, and in NSCLC cells. We revealed that the biogenesis of AS-tDR-008,272 was induced by angiogenin (ANG) under hypoxic conditions. Functional assays indicated that AS-tDR-008,272 promoted proliferation, migration, and glycolysis metabolism capacities of NSCLC cells. While inhibition of AS-tDR-008,272 suppressed NSCLC cell growth in vitro and in vivo. Clinically, higher expression of AS-tDR-008,272 in NSCLC tumor tissues was associated with advanced TNM stage, poorer survival, and SUVmax of ¹⁸F-FDG PET/CT scan in NSCLC patients. Mechanistically, AS-tDR-008,272 enhanced NSCLC cell malignancy by interacting with HJURP through a dual regulatory mechanism: binding to the coding sequence (CDS) of HJURP mRNA to regulate its transcription and enhancing the abundance of HJURP mRNA in polysomes to promote its translation. Our findings reveal a previously unrecognized tRF-mediated glycolysis reprogramming mechanism in NSCLC tumorigenesis. AS-tDR-008,272 may represent a promising prognostic marker and therapeutic target for NSCLC.