ADAR-mediated RNA editing regulates PVR immune checkpoint in colorectal cancer.

Recent studies have revealed that tumor immunotherapy resistance is influenced by ADAR-mediated RNA editing, but its targets remain unelucidated. Our current study identified the poliovirus receptor (PVR) oncogene, which encodes an immune checkpoint in colorectal cancer (CRC), as a potential target for RNA editing. We performed transcriptome sequencing analysis and experimental validation in two Chinese CRC cohorts. PVR and ADAR expressions significantly increased in CRC tumors and showed positive correlations in both cohorts, coupled with upregulated PVR RNA editing in CRC tumors. Manipulation of ADAR expression by over-expression or knockdown substantially changed PVR expression and RNA editing in HTC116 CRC cells. Luciferase reporter and actinomycin D assays further revealed that RNA editing in PVR 3'-UTR could upregulate PVR RNA expression, probably by increasing the RNA stability. By increasing PVR expression, ADAR-mediate RNA editing might contribute to tumor- and immune-related gene functions and pathways in CRC. Moreover, a signature combining PVR RNA editing and expression showed promising predictive performance in CRC diagnosis in both Chinese CRC cohorts. Our findings thus highlight the importance of ADAR-mediated RNA editing in PVR up-regulation in CRC tumors and provide new insight into the application of PVR RNA editing as a novel diagnostic biomarker for CRC.

F11R RNA trinucleotide over-edited by ADAR in gastric and colorectal cancers: Cross-cohort validation, gene expression regulation, and diagnostic significance.

The F11 receptor (F11R) gene encoding junctional adhesion molecule A has been associated with gastric cancer (GC) and colorectal cancer (CRC), in which its role and regulation remain to be further elucidated. Recently F11R was also identified as a potential target of adenosine-to-inosine (A-to-I) mediated by the adenosine deaminases acting on RNA (ADARs). Herein, using RNA-Seq and experimental validation, our current study revealed an F11R RNA trinucleotide over-edited by ADAR, with its regulation of gene expression and clinical significance in four GC and three CRC cohorts. Our results found an over-edited AAA trinucleotide in an AluSg located in the F11R 3'-untranslated region (3'-UTR), which showed editing levels correlated with elevated ADAR expression across all GC and CRC cohorts in our study. Overexpression and knockdown of ADAR in GC and CRC cells, followed by RNA-Seq and Sanger sequencing, confirmed the ADAR-mediated F11R 3'-UTR trinucleotide editing, which potentially disrupted an RBM45 binding site identified by crosslinking immunoprecipitation sequencing (CLIP-seq) and regulated F11R expression in luciferase reporter assays. Moreover, the F11R trinucleotide editing showed promising predictive performance for diagnosing GC and CRC across GC and CRC cohorts. Our findings thus highlight both the potential biological and clinical significance of an ADAR-edited F11R trinucleotide in GC and CRC, providing new insights into its application as a novel diagnostic biomarker for both cancers.

Exosomal circEIF3K from cancer-associated fibroblast promotes colorectal cancer (CRC) progression via miR-214/PD-L1 axis.

BACKGROUND: Tumor microenvironment (e.g., cancer-associated fibroblast) plays a key role in cancer tumorigenesis and metastasis. However, the detailed mechanism of whether hypoxia promotes CRC progression via tumor microenvironment remains unclear. METHODS: In this study, circEIF3K exosome was examined by NanoSight Tracking Analysis and RT-qPCR. We used cell colony formation assay, transwell assay and tube formation assay to determine proliferation, invasion and metastasis of HCT116 or SW620 cells. Xenograft tumor assay was employed to show in vivo tumor growth of HCT116 cells. RESULTS: We found that hypoxia could induce secretion of circEIF3K exosome. Conditioned medium (CM) and exosome from circEIF3K knockdown CAF significantly attenuated proliferation, invasion and tube formation of HCT116 or SW620 cells, which could be reverted by miR-214 under hypoxia treatment. Besides, we observed that circEIF3K knockdown evidently impaired tumor growth in mice. TCGA dataset analysis showed that low expression of circEIF3K was observed in normal tissues and associated with prolonged survival time. Finally, PD-L1 was confirmed as important target for miR-214 in CRC. CONCLUSION: In conclusion, our study reveals that a novel axis circEIF3K/miR-214/PD-L1 mediates hypoxia-induced CRC progression via CAF, providing the rationale for developing new targeted therapeutics to treat CRC.

Plasma miR-1, but not Extracellular Vesicle miR-1, Functions as a Potential Biomarker for Colorectal Cancer Diagnosis.

BACKGROUND: miRNAs have been proved to function as diagnostic biomarkers. Extracellular vesicles (EVs) are carriers of miRNAs. This study aimed to investigate the diagnostic potential of miR-1 in plasma and extracellular vesicles (EVs) for patients with colorectal cancer (CRC). METHODS: Bioinformatics analysis was used to find a target miRNA and its potential functions. miR-1 was then detected in plasma and EV from 49 control samples and 40 CRC samples. Next, the diagnostic potential of plasma and EV miR-1 were compared based on common biomarkers including CEA and CA211. RESULTS: miR-1 was differentially expressed in CRC. Target gene and function analyses showed that it might participate in cell migration and the regulation of mRNA splicing via the spliceosome. Plasma miR-1 levels in CRC samples were significantly higher than those in control samples, whereas EV miR-1 levels were not statistically different. Based on receiver operating characteristic (ROC) curve analysis, comparing their predictive power compared to that of CEA and CA211, plasma miR-1 performed better and EV miR-1 performed worse. CONCLUSIONS: Our data indicate that plasma miR-1, but not EV miR-1, could function as a potential biomarker for CRC diagnosis.

Effects of prebiotic supplement on gut microbiota, drug bioavailability, and adverse effects in patients with colorectal cancer at different primary tumor locations receiving chemotherapy: study protocol for a randomized clinical trial.

BACKGROUND: The prevalence of colorectal cancer (CRC) worldwide is a huge challenge to human health. Primary tumor locations found to impact prognosis and response to therapy. The important role of gut microbiota in the progression and treatment of CRC has led to many attempts of alleviating chemotherapy-induced adverse effects using microecologics. However, the underlying mechanism of the difference in the prognosis of different primary tumor locations and the synergistic effect of prebiotics on chemotherapy need to be further elucidated. This study aims to explore the differences in tumor microbiota and examine the effectiveness of xylooligosaccharides (XOS) on gut microbiota, adverse effects, and bioavailability of chemotherapy drugs in CRC patients at different primary tumor locations. METHODS: This is a double-blinded, randomized, parallel controlled clinical trial. Participants with left-sided CRC (LSCRC, n = 50) and right-sided CC (RSCC, n = 50) will randomly allocated to prebiotic group (n = 25) or control group (n = 25) and will receive either a daily XOS (3 g/day) or placebo, respectively, for 12 weeks. The primary outcomes will be the differences in the mucosa microbiota composition at different tumor locations and differences in gut microbiota composition, adverse effects, and blood concentration of capecitabine posttreatment. The secondary outcomes will include other blood indicators, short-chain fatty acids (SCFAs) concentration, quality of life, and mental health. DISCUSSION: This study will reveal the potential benefits of prebiotic for improving the gut microbiota composition, alleviating the adverse effects, and improving the efficacy of chemotherapy in patients with CRC. In addition, this study will provide data on the different distribution of tumor microbiota and the different changes of gut microbiota during treatment in LSCRC and RSCC, which may provide novel insights into personalized cancer treatment strategies based on primary tumor locations and gut microbiota in the future. TRIAL REGISTRATION: Chinese Clinical Trial Registry ( www.chictr.org.cn ): ChiCTR2100046237. Registered on 12 May 2021.

Gut Microbiota Signatures in Tumor, Para-Cancerous, Normal Mucosa, and Feces in Colorectal Cancer Patients.

Background: Association studies have linked microbiome alterations with colorectal cancer (CRC). However, differences in tumor, para-cancerous, normal mucosal, and fecal microbiota remain to be strengthened. Methods: We performed a study on the ecologically rich and taxonomically diverse of gut microbiota using three types of colorectal mucosa (tumor mucosa, para-cancerous mucosa, normal mucosa) and feces from 98 CRC patients. Additionally, we profiled the microbiota in the fecal occult blood test (FOBT) positive and negative groups at different sampling sites. Results: We found striking variations between tumor mucosal microbiota and normal mucosal microbiota. However, there was no significant difference between tumor and para-cancerous mucosal microbiota, as well as between para-cancerous and normal mucosal microbiota, revealing that the para-cancerous mucosal microbiota was a transitional state between the tumor and normal mucosal microbiota. And the substantial shifts in the fecal microbiota compared to mucosal microbiota indicated the risk of using fecal microbiota to define mucosal microbiota. A strong correlation between FOBT positive and Fusobacterium was discovered, indicating this adherent-invasive genus was closely related to intestinal bleeding. Furthermore, we identified six key genera, including Fusobacterium, Gemella, Campylobacter, Peptostreptococcus, Alloprevotella, and Parvimonas, which appear to be consistently over-represented in tumor mucosa compared to normal mucosa and/or in mucosa compared to feces. Conclusion: Compositional alterations in the microbiota existed in three types of colorectal mucosa and feces in CRC patients. Six key genera may contribute to the topographic variances in the microbiota of tumor-bearing colorectum.

MicroRNA-1252-5p, regulated by Myb, inhibits invasion and epithelial-mesenchymal transition of pancreatic cancer cells by targeting NEDD9.

MicroRNAs (miRNAs) are known to be involved in the development and progression of pancreatic cancer (PAC). The expression levels and roles of miR-1252-5p in PAC remain unclear. Quantitative real-time PCR and in situ hybridization were used to detect miR-1252-5p expression in PAC cells and human tissues. We studied the gain and loss of function of miR-1252-5p in the PAC cell lines in vitro and in vivo. The direct targets of miR-1252-5p were analyzed using public databases and a dual-luciferase reporter assay. Expression levels of miR-1252-5p are downregulated in PAC cell lines and tissue samples, and its expression is negatively associated with adverse clinical features and poor prognosis. In vitro and in vivo experiments show that miR-1252-5p overexpression inhibits the proliferation, migration, invasion, and epithelial-mesenchymal transition of PAC cells, and miR-1252-5p knockdown enhances these biological behaviors. MiR-1252-5p negatively regulates neural precursor cell expressed, developmentally downregulated 9 (NEDD9) by directly binding its 3'- untranslated region. Further mechanism research revealed that the SRC/STAT3 pathway is involved in miR-1252-5p/NEDD9 mediation of PAC's biological behaviors. We also verified that Myb inhibited miR-1252-5p by directly binding at its promoter. MiR-1252-5p may act as a tumor-suppressing miRNA in PAC and may be a potential therapeutic target for PAC patients.

The effect of attention and interpretation therapy on psychological resilience, cancer-related fatigue, and negative emotions of patients after colon cancer surgery.

BACKGROUND: Colon cancer is the most common malignant tumor of the gastrointestinal tract. This cancer and the related treatments bring a raft of lasting physiological and psychological impacts to patients. This study explored the effects of attention and interpretation therapy (AIT) on improving psychological resilience, cancer-related fatigue (CRF), and negative emotions in patients after colon cancer surgery. METHODS: Patients who had undergone colon cancer surgery in the Affiliated Hospital of Jiangnan University were selected and randomly allocated into an experimental group and a control group, each with 100 cases. Patients in the control group received routine intervention measures, while the experimental group received an extra 10 weeks of AIT. Before and after 10 weeks of intervention, the effects of intervention were evaluated using the Connor-Davidson Resilience Scale (CD-RISC), Self-Rating Anxiety Scale (SAS), Selfrating Depression Scale (SDS) and the Revised Piper Fatigue Scale (PFS-R). RESULTS: Before the intervention, there was no statistical difference between the scores of psychological resilience, CRF, and negative emotions between the two groups (P>0.05). We compared the scores before and after the 10 weeks of intervention and found that the scores of psychological resilience of the experimental group were higher than before, and the scores of CRF and negative emotion were lower than before. After the intervention, the psychological resilience score of the experimental group was higher than that of the control group, the CRF and negative emotions scores were lower than those of the control group, and the differences were statistically significant (P<0.05). CONCLUSIONS: AIT can effectively strengthen the psychological resilience of patients after colon cancer surgery to a certain extent, reduce anxiety and depression, reduce the degree of CRF, and thus improve the patients' quality of life postoperatively.

Anti-Proliferative and Apoptosis-Promoting Effect of microRNA-125b on Pancreatic Cancer by Targeting NEDD9 via PI3K/AKT Signaling.

PURPOSE: The expression of microRNA-125b (miR-125b) is low in a variety of cancers, including gastric, lung, bladder, thyroid, and esophageal cancers. However, its specific mechanism in pancreatic ductal adenocarcinoma (PDAC) remains unclear. This study is aimed to explore the role of miR-125b in PDAC. METHODS: PDAC tissues and adjacent tissues were collected for miR-125b analysis by qRT-PCR. Different PDAC cell lines were cultured for miR-125b detection by qRT-PCR, and CAPAN1 cells were selected for the downstream experiments. Cell proliferation was characterized by methyl thiazolyl tetrazolium (MTT) and 5-bromo-2-deoxyUridine (BrdU) staining. Flow cytometry was utilized for apoptosis and cell cycle changes. Cell invasion was determined by the Transwell assay and the dual-luciferase assay was utilized for validating the target gene. Western blotting was used to detect apoptosis related and PI3K/AKT signaling proteins. RESULTS: miR-125b was significantly down-regulated in human PDAC tissues and cell lines (P < 0.05). miR-125b inhibited the growth and invasion of CAPAN1 cells, facilitated apoptosis, and blocked the cell cycle at the G0/G1 phase. Furthermore, miR-125 directly targeted NEDD9. The high expression of NEDD9 impaired the anti-proliferative and anti-apoptotic activity of miR-125b. miR-125b also inhibited apoptosis-related proteins and PI3K/AKT signaling pathways via NEDD9. CONCLUSION: miR-125b decreased cell growth and invasion, and facilitated apoptosis in CAPAN1 cells through PI3K/AKT inhibition via targeting NEDD9.

Two variants of Interleukin-1B gene are associated with the decreased risk, clinical features, and better overall survival of colorectal cancer: a two-center case-control study.

Interleukin (IL)-1B reportedly promotes the stemness and invasiveness of colon cancer cells. Several studies have investigated the association between IL-1B gene polymorphisms and colorectal cancer (CRC) risk, but report conflicting findings. Here, this association was explored in a hospital-based case-control study involving 527 CRC cases and 639 controls from two Chinese Han populations. Genotyping was done by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The IL-1B expression in CRC patients and controls were obtained from the GEPIA database and the mRNA expressions of different genotypes were downloaded from the GTEx portal database. The relationship of two IL-1B gene loci with clinical parameters and overall survival were analyzed using the Chi-square test and Kaplan-Meier analysis with the log-rank test respectively. It was found that the IL-1B mRNA levels in CRC patients were significantly higher than in controls. Bioinformatic analysis suggested that rs1143634 and rs1143623 polymorphisms decreased the IL-1B mRNA expression. The two polymorphisms were associated with decreased risk for CRC. Stratified analyses revealed the IL-1B gene rs1143623 and rs1143634 polymorphisms decreased the risk of CRC among females, smokers and drinkers. Moreover, the CC and/or GC genotype of rs1143623 polymorphism were correlated with decreased risk among CRC patients with tumor size ≥5cm, TNM stage III+IV, and rectal cancer. For rs1143634 polymorphism, the CT genotype reduced the risk of colorectal adenocarcinoma. The CRC patients carrying CC genotype of rs1143623 polymorphism were associated with better overall survival. In conclusion, IL-1B gene rs1143623 and rs1143634 polymorphisms are associated with decreased risk for CRC patients and thereby play important roles in the etiology of CRC.

Protective effects of Atractylodes macrocephala polysaccharide on liver ischemia-reperfusion injury and its possible mechanism in rats.

Atractylodes macrocephala polysaccharide (AMP), a traditional Chinese medicine, is thought to have protective effects against liver injury. Therefore, this study was designed to explore the effects of AMP on hepatic ischemia-reperfusion injury (IRI) and elucidate the possible mechanisms. Ninety-six Sprague-Dawley rats were randomly divided into four groups with 24 rats per group: a normal control group, an IRI group, an AMP-treated group (0.4 g/kg/d) and a bifendate-treated group (100 mg/kg). Rats were treated with AMP or bifendate once daily for seven days by gastric gavage. The normal control group and the IRI model group received an equivalent volume of physiological saline. At 1, 6 and 24 h after surgery, the rats were killed and liver tissue samples were obtained to determine interleukin-1 (IL-1) expression by Western blotting and nuclear factor-κB (NF-κB) expression by immunohistochemistry. Liver morphology was assessed by microscopy and transmission electron microscopy. Blood samples were obtained to measure liver function (alanine aminotransferase, aspartate aminotransferase, total bilirubin and direct bilirubin). AMP significantly reduced the elevated expression of markers of liver dysfunction and the hepatic morphologic changes induced by hepatic IRI in rats. AMP also markedly inhibited IRI-induced lipid peroxidation and altered the activities of the antioxidant enzyme superoxide dismutase and malondialdehyde levels. Moreover, pretreatment with AMP suppressed the expression of interleukin-1ß and NF-kB in IRI-treated rats. These results suggest that AMP exerts protective and therapeutic effects against hepatic IRI in rats, which might be associated with its antioxidant properties and inhibition of NF-κB activation. More studies are needed to better understand the mechanisms underlying the protective effects of AMP on hepatic IRI.