Exosome circATP8A1 induces macrophage M2 polarization by regulating the miR-1-3p/STAT6 axis to promote gastric cancer progression.

Circular RNAs (circRNAs) play important roles in gastric cancer progression but the regulatory role of circRNAs in controlling macrophage function remains elusive. Exosomes serve as cargo for circRNAs and play a crucial role as mediators in facilitating communication between cancer cells and the tumor microenvironment. In this study, we found that circATP8A1, a previously unreported circular RNA, is highly expressed in both gastric cancer tissues and exosomes derived from plasma. Increased circATP8A1 was associated with advanced TNM stage and worse prognosis in patients with gastric cancer. We showed that  the circATP8A1 knockdown significantly inhibited gastric cancer proliferation and invasion in vitro and in vivo. Functionally, exosome circATP8A1 induced the M2 polarization of macrophages through the STAT6 pathway instead of the STAT3 pathway. Mechanistically, circATP8A1 was shown to activate the STAT6 pathway through competitive binding to miR-1-3p, as confirmed by Fluorescence In Situ Hybridization (FISH), RNA immunoprecipitation, RNA pulldown, and Luciferase reporter assays. The reversal of circATP8A1-induced STAT6 pathway activation and macrophage polarization was observed upon blocking miR-1-3p. Macrophages treated with exosomes from gastric cancer cells overexpressing circATP8A1 were able to promote gastric cancer migration, while knockdown of circATP8A1 reversed these effects in vivo. In summary, exosome-derived circATP8A1 from gastric cancer cells induce macrophages M2 polarization via the circATP8A1/miR-1-3p/STAT6 axis, and tumor progression. Our results highlight circATP8A1 as a potential prognostic biomarker and therapeutic target in gastric cancer.

Pumilio1 regulates NPM3/NPM1 axis to promote PD-L1-mediated immune escape in gastric cancer.

Abnormal regulation of RNA binding proteins (RBPs) plays an essential role in tumorigenesis and progression, but their functions and mechanisms remain largely elusive. Previously, we reported that Pumilio 1 (PUM1), a RBP, could regulate glycolysis metabolism and promote the progression of gastric cancer (GC). However, the role of PUM1 in tumor immune regulation remains largely elusive. In this study, we report that PUM1 induces immune escape through posttranscriptional regulation of PD-L1 in GC. We used multiplexed immunohistochemistry to analyze the correlation between PUM1 expression and immune microenvironment in GC. The effect of PUM1 deficiency on tumor killing of T cells was examined in vitro and in vivo. The molecular mechanism of PUM1 was evaluated via RNA immunoprecipitation, chromatin immunoprecipitation, Western blot, co-immunoprecipitation, and RNA stability assays. Clinically, elevated PUM1 expression is associated with high-expression of PD-L1, lack of CD8+ T cell infiltration and poor prognosis in GC patients. PUM1 positively regulates PD-L1 expression and PUM1 reduction enhances T cell killing of tumors. Mechanistically, PUM1 directly binds to nucleophosmin/nucleoplasmin 3 (NPM3) mRNA and stabilizes NPM3. NPM3 interacts with NPM1 to promote NPM1 translocation into the nucleus and increase the transcription of PD-L1. PUM1 inhibits the anti-tumor activity of T cells through the PUM1/NPM3/PD-L1 axis. In summary, this study reveals the critical post-transcriptional effect of PUM1 in the modulation of PD-L1-dependent GC immune escape, thus provides a novel indicator and potential therapeutic target for cancer immunotherapy.

PUM1 Promotes Tumor Progression by Activating DEPTOR-Meditated Glycolysis in Gastric Cancer.

RNA-binding proteins (RBPs) play essential roles in tumorigenesis and progression, but their functions in gastric cancer (GC) remain largely elusive. Here, it is reported that Pumilio 1 (PUM1), an RBP, induces metabolic reprogramming through post-transcriptional regulation of DEP domain-containing mammalian target of rapamycin (mTOR)-interacting protein (DEPTOR) in GC. In clinical samples, elevated expression of PUM1 is associated with recurrence, metastasis, and poor survival. In vitro and in vivo experiments demonstrate that knockdown of PUM1 inhibits the proliferation and metastasis of GC cells. In addition, RNA-sequencing and bioinformatics analyses show that PUM1 is enriched in the glycolysis gene signature. Metabolomics studies confirm that PUM1 deficiency suppresses glycolytic metabolism. Mechanistically, PUM1 binds directly to DEPTOR mRNA pumilio response element to maintain the stability of the transcript and prevent DEPTOR degradation through post-transcriptional pathway. PUM1-mediated DEPTOR upregulation inhibits mTORC1 and alleviates the inhibitory feedback signal transmitted from mTORC1 to PI3K under normal conditions, thus activating the PI3K-Akt signal and glycolysis continuously. Collectively, these results reveal the critical epigenetic role of PUM1 in modulating DEPTOR-dependent GC progression. These conclusions support further clinical investigation of PUM1 inhibitors as a metabolic-targeting treatment strategy for GC.

Construction of a hypoxia-immune-related prognostic panel based on integrated single-cell and bulk RNA sequencing analyses in gastric cancer.

Introduction: Gastric cancer (GC) is the fifth most common tumor, contributing to the third-highest number of cancer-related deaths. Hypoxia is a major feature of the tumor microenvironment. This study aimed to explore the influence of hypoxia in GC and establish a hypoxia-related prognostic panel. Methods: The GC scRNA-seq data and bulk RNA-seq data were downloaded from the GEO and TCGA databases, respectively. AddModuleScore() and AUCell() were used to calculate module scores and fractions of enrichment for hypoxia-related gene expression in single cells. Least absolute shrinkage and selection operator cox (LASSO-COX) regression analysis was utilized to build a prognostic panel, and hub RNAs were validated by qPCR. The CIBERSORT algorithm was adopted to evaluate immune infiltration. The finding of immune infiltration was validated by a dual immunohistochemistry staining. The TIDE score, TIS score and ESTIMATE were used to evaluate the immunotherapy predictive efficacy. Results: Hypoxia-related scores were the highest in fibroblasts, and 166 differentially expressed genes were identified. Five hypoxia-related genes were incorporated into the hypoxia-related prognostic panel. 4 hypoxia-related genes (including POSTN, BMP4, MXRA5 and LBH) were significantly upregulated in clinical GC samples compared with the normal group, while APOD expression decreased in GC samples. Similar results were found between cancer-associated fibroblasts (CAFs) and normal fibroblasts (NFs). A high hypoxia score was associated with advanced grade, TNM stage, N stage, and poorer prognosis. Decreased antitumor immune cells and increased cancer-promoting immune cells were found in patients with high hypoxia scores. Dual immunohistochemistry staining showed high expression of CD8 and ACTA2 in gastric cancer tissue. In addition, the high hypoxia score group possessed higher TIDE scores, indicating poor immunotherapy benefit. A high hypoxia score was also firmly related to sensitivity to chemotherapeutic drugs. Discussion: This hypoxia-related prognostic panel may be effective in predicting the clinical prognosis, immune infiltrations, immunotherapy, and chemotherapy in GC.

Retrospective analysis of risk factors for distant metastasis of early-onset gastric cancer during the perioperative period.

Background: Although the overall global incidence of gastric cancer has been declining, the number of new cases in people under the age of 50 is increasing, which is related to metastasis, late pathological stages, and poor prognosis. There is a scarcity of large-scale studies to evaluate and predict distant metastasis in patients with early-onset gastric cancer. Methods: From January 2010 to December 2019, data on early-onset GC patients undergoing surgery were gathered from the Surveillance, Epidemiology, and End Results (SEER) database. We investigated the independent risk factors for distant metastasis in patients with early-onset gastric cancer. Based on these risk factors, we developed a nomogram to predict distant metastasis. The model underwent internal validation on the test set and external validation on 205 patients from the First Affiliated Hospital of Sun Yat-sen University and the seventh Affiliated Hospital of Sun Yat-sen University. The novel nomogram model was then evaluated using the receiver operating characteristic (ROC) curve, calibration, the area under the curve (AUC), and decision curve analysis (DCA). The training set nomogram score was used to classify the different risk clusters of distant metastasis. Results: Our study enrolled 2217 patients after establishing the inclusion and exclusion criteria, with 1873 having no distant metastasis and 344 having distant metastasis. The tumor size, total lymph nodes, whether or not receiving radiotherapy and chemotherapy, T stage, and N stage were significant predictors of advanced distant metastasis (p < 0.05). The AUC of the ROC analysis demonstrated our model's high accuracy. Simultaneously, the prediction model shows high stability and clinical practicability in the calibration curve and DCA analysis. Conclusions: We developed an innovative nomogram containing clinical and pathological characteristics to predict distant metastasis in patients younger than 50 years old with gastric cancer. The tool can alert clinicians about distant metastasis and help them develop more effective clinical treatment plans.

Tumor-derived extracellular vesicles shuttle c-Myc to promote gastric cancer growth and metastasis via the KCNQ1OT1/miR-556-3p/CLIC1 axis.

Gastric cancer (GC) is a heterogeneous disease with poor prognosis. Tumor-derived extracellular vesicles (EVs) assume a role in intercellular communication by carrying various molecules, including proteins, RNA, and DNAs, which has been identified to exhibit oncogenic effect in GC. Therefore, this research aimed to figure out whether tumor-derived EVs transmit c-Myc to orchestrate the growth and metastasis of GC. KCNQ1OT1, microRNA (miR)-556-3p and CLIC1 expression of GC tissues was detected through RT-qPCR. EVs were isolated from GC cells, followed by RT-qPCR and Western blot analysis of c-Myc expression in EVs and GC cells. Next, GC cells were incubated with EVs or transfected with a series of mimic, inhibitor, or siRNAs to assess their effects on cell viability, migrative, invasive, and apoptotic potential. Relationship among c-Myc, KCNQ1OT1, miR-556-3p, and CLIC1 was evaluated by dual-luciferase reporter assay. PI3K/AKT pathway-related proteins were assessed through Western blot analysis. KCNQ1OT1 and CLIC1 were highly expressed but miR-556-3p in GC tissues. c-Myc was high-expressed in tumor-derived EVs and GC cells. Mechanistically, c-Myc could induce KCNQ1OT1 expression, and KCNQ1OT1 bound to miR-556-3p that negatively targeted CLIC1 to inactivate PI3K/AKT pathway. Tumor-derived EVs, EVs-c-Myc, KCNQ1OT1 or CLIC1 overexpression, or miR-556-3p inhibition promoted GC cell proliferative, invasive, and migrative capacities but repressed their apoptosis through activating PI3K/AKT pathway. Collectively, tumor-derived EVs carrying c-Myc activated KCNQ1OT1 to downregulate miR-556-3p, thus elevating CLIC1 expression to activate the PI3K/AKT pathway, which facilitated the growth and metastasis of GC.

Development and Validation of the Chinese Version of the Quality of Recovery-40 Questionnaire.

PURPOSE: The present study aimed to develop the official Chinese version of the QoR-40 (QoR-40C) and to test its reliability, validity, and responsiveness. PATIENTS AND METHODS: A systematic translation procedure was established and performed to develop the QoR-40C from the original English QoR-40 version. After the pilot study, 223 surgical patients were administered  the QoR-40C at four time points. The validity, reliability, and responsiveness were assessed to validate the QoR-40C. RESULTS: The test-retest reliability of the QoR-40C in the morning and afternoon of the third day after surgery was 0.917 (P < 0.001). The split-half reliability for all domains was 0.938 in the morning of the third day after surgery. The median item-to-own dimension and total score of Cronbach's α for internal consistency of the QoR-40C at different assessment time points were more than 0.70. All the correlation coefficients between each subscale and the QoR-40 total score showed good correlation and were greater than those for other subscales in the morning of the third day after surgery. Furthermore, in the morning of the third day after surgery, the QoR-40C total score was moderately positively correlated with the SF-36 score (ρ = 0.575, P < 0.001), while the QoR-40C score was negatively correlated with the visual analogue scale (VAS) score (ρ = -0.299, P < 0.001). The factor loadings of each item were within the required range. A statistically significant difference was observed in the QoR-40C total scores before and after the surgery (P < 0.001) with the standardized responsive mean (SRM) of 0.51. CONCLUSION: The QoR-40C showed good reliability, validity, and responsiveness and was appropriate to be used as a quality of life measurement questionnaire for patients after surgery in China.

RNA-sequencing investigation identifies an effective risk score generated by three novel lncRNAs for the survival of papillary thyroid cancer patients.

Scholars are striving to apply molecular biology involving long non-coding RNA (lncRNA) in the prognostication of papillary thyroid cancer (PTC). However, the clinical role of lncRNAs in the prognostic setting of PTC is still unclear. Herein, a comprehensive inquiry was performed to screen lncRNA expression profiling with 507 PTC patients from The Cancer Genome Atlas RNA-sequencing datasets. A total of 734 lncRNAs were detected to be aberrantly expressed, among which three novel lncRNAs including AC079630.2, CRNDE and CTD-2171N6.1 were markedly related to the progression and survival of PTC. Furthermore, the aberrant expression of these lncRNAs could be verified by other cohorts from gene expression omnibus (GEO) as detected by microarrays. Next, we established a three-lncRNA signature and divided the PTC patients into two subgroups of high- and low-risk. Interestingly, patients with high-risk tended to gain obviously poorer outcome. Most importantly, this three-lncRNA signature was an independent biomarker to predict the patient survival of PTC. The accurate molecular roles of these three lncRNAs remains unclarified and warrants further characterization, but our current data propose that they might play pivotal roles in PTC tumorigenesis and more importantly, these novel lncRNAs are closely related to patients' survival. These discoveries will have far-reaching consequences with respect to molecular prediction of PTC.