Background: Immunotherapy brings new hope to patients with advanced gastric cancer. However, liver metastases can reduce the efficacy of immunotherapy in patients. Tumor-associated macrophages (TAMs) may be the cause of this reduction in efficacy. SPP1 + TAMs are considered to have immunosuppressive properties. We aimed to investigate the involvement of SPP1 + TAMs in the metastasis of gastric cancer. Methods: The single-cell transcriptome was combined with batched BULK datasets for analysis. Animal models were used to verify the analysis results. Results: We reveal the interaction of SPP1 + TAMs with CD8 + exhausted T cells in metastatic cancer. Among these interactions, GDF15-TGFBR2 may play a key immunosuppressive role. We constructed an LR score to quantify interactions based on ligands and receptors. The LR score is highly correlated with various immune features and clinical molecular subtypes. The LR score may also guide the prediction of the efficacy of immunotherapy and prognosis. Conclusions: The crosstalk between SPP1 + TAMs and CD8 + exhausted T cells plays a key immunosuppressive role in the gastric metastatic cancer microenvironment. Graphical

Tumor growth cascade is a complicated and multistep process with numerous obstacles. Until recently, evidences have shown the involvement of microRNAs (miRNAs) in tumorigenesis and tumor progression of various cancers, including colorectal cancer (CRC). In this study, we explored the role of miR-194 and its downstream pathway in CRC. We acquired data through miRNA microarray profiles, showing that the expression of miR-194 was significantly suppressed in CRC tissues compared with corresponding noncancerous tissues. Decreased miR-194 expression was obviously associated with tumor size and tumor differentiation, as well as TNM stage. Both Kaplan–Meier and multivariate survival analysis showed that downregulated miR-194 was associated with overall survival. Moreover, functional assays indicated that overexpression of miR-194 in CRC cell lines inhibited cell proliferation both in vitro and in vivo. In addition, using dual-luciferase reporter gene assay, we found MAP4K4 was the direct target of miR-194. Silencing of MAP4K4 resulted in similar biological behavior changes to that of overexpression of miR-194. We also observed through Human Gene Expression Array that MDM2 was one of the downstream targets of MAP4K4. Knockdown of MAP4K4 downregulated MDM2 expression through transcription factor c-Jun binding to the −1063 to -1057 bp of the promoter. These results suggest that miR-194, regulating the MAP4K4/c-Jun/MDM2 signaling pathway, might act as a tumor suppressor and serve as a novel target for CRC prevention and therapy.

Objective: The aim of the study was to evaluate the oncological outcomes of complete mesocolic excision (CME) in colon cancer patients. Summary Background Data: CME is considered a standard procedure for colon cancer patients. However, previous evidence regarding the effect of CME on prognosis has fundamental limitations that prevent it from being fully accepted. Methods: Patients who underwent radical resection for colon cancer were enrolled between November 2012 and March 2016. According to the principles of CME, patients were stratified into 2 groups based on intraoperative surgical fields and specimen photographs. The primary outcome was local recurrence-free survival (LRFS). The clinicopathological data and follow-up information were collected and recorded. The final follow-up date was April 2016. The trial was registered in ClinicalTrials.gov (identifier: NCT01724775). Results: There were 220 patients in the CME group and 110 patients in the noncomplete mesocolic excision (NCME) group. Baseline characteristics were well balanced. Compared with NCME, CME was associated with a greater number of total lymph nodes (24 vs 20, P = 0.002). Postoperative complications did not differ between the 2 groups. CME had a positive effect on LRFS compared with NCME (100.0% vs 90.2%, log-rank P < 0.001). Mesocolic dissection (100.0% vs 87.9%, log-rank P < 0.001) and nontumor deposits (97.2% vs 91.6%, log-rank P < 0.022) were also associated with improved LRFS. Conclusions: Our findings demonstrate that, compared with NCME, CME improves 3-year LRFS without increasing surgical risks.

Recent studies have indicated the possible function of miR-217 in tumorigenesis. However, the roles of miR-217 in colorectal cancer (CRC) are still largely unknown. We examined the expression of miR-217 and AEG-1 in 50 CRC tissues and the corresponding noncancerous tissues by qRT-PCR. The clinical significance of miR-217 was analyzed. CRC cell lines with miR-217 upregulation and AEG-1 silencing were established and the effects on tumor growth in vitro and in vivo were assessed. Dual-luciferase reporter gene assays were also performed to investigate the interaction between miR-217 and AEG-1. Our data demonstrated that miR-217 was significantly downregulated in 50 pairs of colorectal cancer tissues. MiR-217 expression levels were closely correlated with tumor differentiation. Moreover, decreased miR-217 expression was also associated with shorter overall survival of CRC patients. MiR-217 overexpression significantly inhibited proliferation, colony formation and invasiveness of CRC cells by promoting apoptosis and G0/G1 phase arrest. Interestingly, ectopic miR-217 expression decreased AEG-1 expression and repressed luciferase reporter activity associated with the AEG-1 3′-untranslated region (UTR). AEG-1 silencing resulted in similar biological behavior changes to those associated with miR-217 overexpression. Finally, in a nude mouse xenografted tumor model, miR-217 overexpression significantly suppressed CRC cell growth. Our findings suggest that miR-217 has considerable value as a prognostic marker and potential therapeutic target in CRC.