Prostate cancer cell-derived exosomal IL-8 fosters immune evasion by disturbing glucolipid metabolism of CD8+ T cell.

Depletion of CD8+ T cells is a major obstacle in immunotherapy; however, the relevant mechanisms remain largely unknown. Here, we showed that prostate cancer (PCa) cell-derived exosomes hamper CD8+ T cell function by transporting interleukin-8 (IL-8). Compared to the low IL-8 levels detected in immune cells, PCa cells secreted the abundance of IL-8 and further accumulated in exosomes. The delivery of PCa cell-derived exosomes into CD8+ T cells exhausted the cells through enhanced starvation. Mechanistically, exosomal IL-8 overactivated PPARα in recipient cells, thereby decreasing glucose utilization by downregulating GLUT1 and HK2 but increasing fatty acid catabolism via upregulation of CPT1A and ACOX1. PPARα further activates uncoupling protein 1 (UCP1), leading to fatty acid catabolism for thermogenesis rather than ATP synthesis. Consequently, inhibition of PPARα and UCP1 restores CD8+ T cell proliferation by counteracting the effect of exosomal IL-8. This study revealed that the tumor exosome-activated IL-8-PPARα-UCP1 axis harms tumor-infiltrating CD8+ T cells by interfering with energy metabolism.

Phenotype and genotype analysis for Helicobacter pylori antibiotic resistance in outpatients: a retrospective study.

To investigate the antibiotic resistance of Helicobacter pylori (H. pylori) in outpatients and to explore the consistency between genotype and phenotype of H. pylori antibiotic resistance. A retrospective study on outpatients screened with urea breath test for H. pylori infection in Nanjing First Hospital from April 2018 to January 2022. Patients who tested positive underwent a consented upper endoscopy, and the H. pylori infection was confirmed by rapid urease test (RUT) and H. pylori culture. For antibiotic resistance phenotype analysis, the H. pylori strains isolated from gastric biopsy were tested for antibiotic resistance phenotype by the Kirby-Bauer disk diffusion test. In addition, the antibiotic resistance genotype of isolated H. pylori was tested with a real-time polymerase chain reaction. A total of 4,399 patients underwent H. pylori infection screening, and 3,306 H. pylori strains were isolated. The antibiotic resistance phenotype test revealed that the resistance rates of metronidazole (MTZ), clarithromycin (CLR), levofloxacin (LEV), amoxicillin (AMX), furazolidone (FR), and tetracycline (TE) were 74.58%, 48.61%, 34.83%, 0.76%, 0.27%, and 0.09%, respectively. Additionally, the antibiotic resistance genotype test revealed that rdxA gene mutation A610G (92.96%), A91G (92.95%), C92A (93.00%), and G392A (95.07%) were predominant in H. pylori with MTZ resistance; 23S rRNA gene mutation A2143G (86.47%) occurred in most H. pylori with CLR resistance; and gyrA gene mutation 87Ile/Lys/Tyr/Arg (97.32%) and 91Asn/Gly/Tyr (90.61%) were the most popular mutations in strains with LEV resistance. The phenotypic resistance and genotypic resistance to CLR (kappa value = 0.824) and LEV (kappa value = 0.895) were in good agreement. The history of eradication with MTZ, CLR, LEV, and AMX was correlated with H. pylori resistance. In short, this study demonstrated that drug resistance of H. pylori was mainly to MTZ, CLR, and LEV in local outpatients. Three drugs can be selected for increased MICs (Minimum Inhibitory Concentration) via single chromosomal mutations. In addition, the genotype could be used to predict the phenotypic H. pylori resistance to CLR and LEV. IMPORTANCE Helicobacter pylori is a key bacterium that causes stomach diseases. There was a high prevalence of H. pylori in the Chinese population. We analyzed the resistance phenotype and genotype characteristics of H. pylori in 4,399 outpatients at the First Hospital of Nanjing, China. We found a higher resistance rate to metronidazole (MTZ) , clarithromycin (CLR), and levofloxacin (LEV), and the genotype could be used to predict the phenotypic H. pylori resistance to CLR and LEV. This study provides information on H. pylori infection and also provides guidance for clinical doctors' drug treatment.

The Role of N6-Methyladenosine-Associated lncRNAs in the Immune Microenvironment and Prognosis of Colorectal Cancer.

Background: The role of N6-methyladenosine long noncoding RNAs (lncRNAs) in colorectal cancer (CRC) is elusive. Materials and Methods: We identified m6A-associated lncRNAs by using the data gathered from The Cancer Genome Atlas (TCGA) and stratified CRC patients into different subgroups. Cox regression analysis was performed to construct an m6A-associated lncRNA signature. The role of this signature in the immune microenvironment and prognosis was dissected subsequently. Finally, a gene set enrichment analysis (GSEA) was conducted to predict the possible mechanisms based on the signature. Results: Three m6A-associated clusters were constructed from 866 differentially expressed lncRNAs. Cluster 2 had poor prognosis and low immune cell infiltration. An m6A-associated lncRNA signature consisting of 14 lncRNAs was constructed and recognized as an independent prognostic indicator of CRC by using survival analysis and receiver operating characteristic (ROC) curves. The clinical features and immune cell infiltration status were significantly different in patients stratified by the risk score. Furthermore, GSEA showed that the P53 pathway and natural killer cell-mediated cytotoxicity were more enriched in the low-risk group. Conclusion: Our data revealed that m6A-associated lncRNAs could be potential prognostic indicators of immunogenicity in CRC.

Identification of autophagy related genes in predicting the prognosis and aiding 5- fluorouracil therapy of colorectal cancer.

The emergence of 5-Fluorouracil (5-FU) resistance is the barrier to effective clinical outcomes for colorectal cancer (CRC) patients. Autophagy was found to be involved in protecting tumor cells from 5-FU. However, the specific role of autophagy-related genes in CRC 5-FU resistance remains unclear. In this study, HSPB8 among 34 differentially expressed ARGs in CRC was identified to be the hub ARGs in 5-FU resistant which was down-regulated in CRC samples when compared with normal samples but up-regulated in CRC samples with relatively higher lymphatic invasion, later stages and poor prognosis of CRC. Mechanistic analysis demonstrated that due to the recruitment of CAFs, HSPB8 expression was enhanced in CRC cells so that HSPB8 could act together with its co-chaperone BAG3 in autophagy drived 5-FU resistance. Furthermore, the augmented expression level of HSPB8 was found to be significantly correlated to the immune cell infiltration such as Treg cells, macrophages, monocyte and dendritic cells and so on. Our results suggested CAFs driving HSPB8 induced CRC 5-FU resistance by promoting tumor autophagy would provide a new strategy in seeking potential CRC therapeutic target.

The value of circulating tumor cells with positive centromere probe 8 in the diagnosis of small pulmonary nodules.

Circulating cancer cells (CTCs) can serve as a non-invasive liquid biopsy and provide opportunities for early cancer diagnosis and evaluation. However, the value of CTCs for diagnosis or prognosis of small pulmonary nodules (SPNs) is unclear. Fifty-three patients diagnosed with SPNs with a diameter less than 30 mm by CT examination were enrolled in the study. The CTC numbers, CT examination features, serum tumor marker concentrations, and histopathological characteristics were analyzed. Centromere probe 8 (CEP8) was used as a marker for CTC identification. The CTC numbers were significantly different in patients with malignant and benign SPNs and with early (0/Ⅰa) and advanced (Ⅰb/Ⅱ/Ⅲ) lung cancer stages. ROC analysis showed that the CTC numbers was effective on malignant SNP diagnosis. The combined use of CTCs and the density features of the nodules determined by CT further improved the overall screening, the diagnostic effectiveness for malignant SNPs, and determination of the pTNM (≤Ia vs.>Ia) stage. The CT morphology revealed that large, single, and solid SPNs were associated with significant CTC numbers and the CTC numbers were correlated with malignant histopathology. Using CEP8 as a marker resulted in detection of more CTC numbers in 22 patient samples triple stained for CEP8, EpCAM, and CKs. The CTCs determined by CEP8-positive staining could serve as potential screening and diagnostic markers for malignant SPNs.