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Simple Summary: High-fat diet (HFD) is hypothesized to induce gut dysbiosis and promote colorectal cancer (CRC). However, the specific mechanisms involved require investigation. In this study, we established an animal model and utilized 16S sequencing to determine the effects of HFD on gut microbiota, as well as on the colon and liver. Furthermore, due to the abundance of Desulfovibrio (DSV) in the faecal samples of HFD-fed rats and CRC hepatic metastasis patients, we also conducted a DSV gavage animal experiment to determine the role of DSV in CRC development. Our study confirmed that HFD could cause microbiota dysbiosis, especially DSV enrichment, and may promote CRC initiation and metastasis. Obesity, metabolic changes, and intestinal microbiota disruption significantly affect tumorigenesis and metastasis in colorectal cancer (CRC). However, the relationships among these factors remain poorly understood. In this study, we found that a high-fat diet (HFD) promoted gut barrier dysfunction and inflammation in the colorectum and liver. We further investigated gut microbiota changes through 16S rRNA sequencing of faecal samples from HFD-fed rats and CRC hepatic metastasis patients and found an abundance of Desulfovibrio (DSV). DSV could also induce barrier dysfunction in the colorectum and inflammation in the colorectum and liver, suggesting that it contributes to the formation of a microenvironment conducive to CRC tumorigenesis and metastasis. These findings highlight that HFD-induced microbiota dysbiosis, especially DSV abundance, could promote CRC initiation and metastasis. [ABSTRACT FROM AUTHOR]

Background: Gastrointestinal tumors are a leading cause of mortality worldwide. As shown in our previous study, miR-1290 is overexpressed in colorectal cancer (CRC) and promotes tumor progression. We therefore aimed to explore the potential of circulating miR-1290 as a biomarker for gastrointestinal cancer.Methods: A serum miRNA sequencing analysis was performed. Then, circulating miRNA detection technologies were established. The expression of miR-1290 was analyzed in gastrointestinal tumor cell lines and culture supernatants. Expression levels of circulating miR-1290 in clinical samples were examined. Associations between miR-1290 expression and clinicopathologic characteristics were analyzed. Xenograft models were generated to assess the fluctuation in serum miR-1290 levels during disease progression.Results: Through miRNA sequencing, we identified that miR-1290 was overexpressed in serum samples from patients with CRC. We confirmed that human gastrointestinal tumor cells express and secrete miR-1290. The circulating miR-1290 levels was up-regulated in patients with pancreatic cancer (PC) (p < 0.01), CRC (p < 0.05), and gastric cancer (GC) (p < 0.01). High miR-1290 expression levels were associated with tumor size, lymphatic invasion, vascular invasion, distant metastasis, tumor differentiation and AJCC stage in patients with PC and CRC. The area under the curve (AUC) was 0.8857 in patients with PC, with 60.9% sensitivity and 90.0% specificity. The AUC was 0.7852 in patients with CRC, with 42.0% sensitivity and 90.0% specificity. In patients with GC, the AUC was 0.6576, with 26.0% sensitivity and 90.0% specificity. The in vivo model verified that the circulating miR-1290 level was significantly increased after tumor formation and decreased after drug treatment.Conclusions: Our findings indicate that circulating miR-1290 is a potential biomarker for gastrointestinal cancer diagnosis and monitoring. [ABSTRACT FROM AUTHOR]

Background and Objective. FBXW7, known as a general tumor suppressor, is commonly lowly expressed in metastatic malignancies. We aim to investigate the potential influence of FBXW7 overexpression on renal cell carcinoma (RCC) metastasis. Methods. We employed quantitative real-time PCR (qRT-PCR) and Western blotting (WB) to quantify the FBXW7 expression in RCC cell lines. Upregulation of FBXW7 was performed in vitro on RCC cells using the lentivirus covering coding region FBXW7 cDNA sequence, and functional tests were performed to verify FBXW7 overexpression on migration and invasion of RCC cells. Moreover, WB was employed to determine the expressions of MMP-2, MMP-9, and MMP-13, as well as EMT markers in the transfected RCC cells. Results. FBXW7 was significantly downregulated in RCC cell lines, dominated by 786-O and ACHN, when compared to normal renal cell line HK-2. Moreover, upregulation of FBXW7 in 786-O and ACHN cell lines significantly inhibited cell migration and invasion, as well as EMT. Present study also showed that FBXW7 was involved in the migration and invasion of RCC cells via regulating the expressions of MMP-2, MMP-9, and MMP-13. Conclusion. Our findings demonstrate that upregulation of FBXW7 inhibits RCC metastasis and EMT. FBXW7 is a potential therapeutic target for RCC patients. [ABSTRACT FROM AUTHOR]