Therapeutic antibodies targeting PD-1 have made major breakthroughs in cancer treatment. However, the majority of colorectal cancer (CRC) cases are microsatellite stable (MSS) and do not respond to anti-PD-1-based immunotherapy. Combination therapy will be an ideal strategy to overcome this limitation. Gegen Qinlian decoction (GQD), a classical traditional Chinese medicine (TCM) formula, has been clinically proven to be effective in the treatment of ulcerative colitis (UC) and type 2 diabetes mellitus. Here, a systemic pharmacological study revealed that GQD acts through multiple targets and pathways in the human body. Combination therapy with GQD and anti-mouse PD-1 potently inhibited the growth of CT26 tumours in a xenograft model. Gut microbiota analysis revealed that combination therapy with GQD and anti-mouse PD-1 significantly enriched for s__Bacteroides_acidifaciens and s__uncultured_organism_g__norank_f__Bacteroidales_S24-7_group . Based on metabolomic analyses, profoundly altered metabolites were identified in the combination therapy group. Two metabolic signalling pathways, namely, glycerophospholipid metabolism and sphingolipid metabolism, were explored. In particular, we found that combination therapy with GQD and anti-mouse PD-1 significantly increased the proportion of CD8+ T cells in peripheral blood and tumour tissues. Direct treatment with GQD and anti-mouse PD-1 increased the expression of IFN-γ, which is a critical factor in antitumour immunotherapy. In addition, combination therapy with GQD and anti-mouse PD-1 downregulated PD-1 and increased IL-2 levels, suggesting that the combination therapy could effectively restore T-cell functions by suppressing inhibitory checkpoints. The application of the Chinese medicinal formula GQD with PD-1 blockade-based immunotherapy can be a novel therapeutic strategy for CRC patients with MSS tumours.

FMT can change intestinal microbiota in sepsis patients, and vagus nerve is a key mediator between intestinal microbiota and SAE. These findings suggest that FMT and vagus nerve are potential therapy targets for treating SAE.

Abstract. The aim of the present study was to investigate the effect of hepatocyte growth factor receptor (c-MET) inhibition on the viability of colon cancer cells and xenografts exposed to irradiation using short hairpin (sh)RNA or the c-MET inhibitor PHA665752. The underlying mechanisms were also investigated. Human colorectal adenocarcinoma HT-29 cells were infected with a lentivirus expressing shRNAs against c-MET and were irradiated at 0, 2, 4, 6 and 8 Gy. The viability of the cells was assessed by alamarBlue ® assays. Mice bearing human colon carcinoma SW620 xenografts were randomly selected to receive 2.5% dimethyl sulfoxide (DMSO), 25 mg/kg PHA665752 intraperitoneally once every 2 days for 3 weeks, irradiation at 10 Gy, or 25 mg/kg PHA665752 intraperitoneally once every 2 days for 3 weeks followed 24 h later by irradiation at 10 Gy. The mean tumor volume (MTV) was measured. The apoptotic rate of cells was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assays, and double stranded break marker antibody γ-H2AX and hypoxia inducible factor (HIF)-1α expression was examined by immunohistochemistry. alamarBlue assays revealed that c-MET downregulation by shRNA markedly accentuated the irradiation-induced reduction in the viability of HT-29 cells compared with HT-29 cells irradiated at the same doses (P<0.05). A combination of irradiation and PHA665752 caused an additional reduction in the MTV (382.8±42.4 mm 3 ; P<0.01 vs. irradiation and PHA665752, 998.0±180.6 and 844.8±190.0 mm 3 , respectively). TUNEL assays revealed that irradiation and PHA665752 alone caused significant apoptosis of the SW620 cells in the tumor xenografts (P<0.01 vs. DMSO). The apoptotic index in the tumor xenografts of mice treated with a combination of irradiation and PHA665752 was significantly increased compared with mice treated with either agent alone (P<0.01). The combination of irradiation and PHA665752 was also associated with a marked increase in γ-H2AX levels and a significant decrease in HIF-1α expression in the xenografts (P<0.01). In conclusion, c-MET inhibition sensitizes colorectal cancer cells to irradiation by enhancing the formation of DNA double strand breaks and possibly alleviating tumor hypoxia. IntroductionWorldwide, colorectal cancer (CRC) is the third most common cancer (1). Currently, the standard regimen for newly diagnosed patients with locally advanced rectal cancer (grade, cT3/T4 and cN + ) is surgery in combination with neoadjuvant radiochemotherapy (2,3). However, the majority of patients have mid to advanced stage CRC at the time of diagnosis. Neoadjuvant radiochemotherapy improves the survival and anus-preservation rates by shrinking tumors, decreasing the clinical stage and reducing the pathological grade (4). While patients with local CRC have a more favorable outcome, with a 5-year survival rate of 90%, patients with metastatic CRC have a poor 5-year survival rate of 12%, despite the good therapeutic regimens that are available, including surgical resection, ad...

The aim of the present study was to examine the role of protease-activated receptor-1 (PAR1)-stimulated platelet activation in the epithelial-mesenchymal transition (EMT) and migration of colon cancer cells, and to identify the underlying mechanisms. TFLLR-NH2, a PAR1 agonist, was used to activate platelets and the platelet supernatants were used to treat the SW620 colon cancer cell line. Expression of E-cadherin and vimentin on SW620 cells was detected by immunofluorescence and western blotting, and the level of the transforming growth factor β1 (TGF-β1) was measured using ELISA following the activation of platelets by TFLLR-NH2. miR-200b expression was detected using quantitative PCR in SW620 cells. In order to investigate the chemotactic ability of the SW620 cells, the expression of CXC chemokine receptor type 4 (CXCR4) was measured by flow cytometry. Transwell migration assays were performed following exposure of the cells to the supernatant of PAR1-activated platelets. SW620 cells cultured in the supernatant of TFLLR-NH2-activated platelets upregulated E-cadherin expression and downregulated the vimentin expression. In the in vitro platelet culture system, a TFLLR-NH2 dose-dependent increase of secreted TGF-β1 was detected in the supernatant. The activation of PAR1 on the platelets led to the inhibition of miR-200b expression in the SW620 cells that were cultured in platelet-conditioned media. The number of SW620 cells that penetrated through the Transwell membrane increased with the dose of TFLLR-NH2 used to treat the platelets. The percentage of CXCR4-positive SW620 cells was significantly higher when they were exposed to the supernatant of platelets cultured for 24 h with PAR1 agonist than when cultured in non-conditioned media (40.89±6.74 vs. 3.47±1.40%, P<0.01). Platelet activation with a PAR1 agonist triggered TGF-β secretion, which induced EMT of SW620 human colon cancer cells via the downregulation of miR-200b expression, and activated platelets had a chemotactic effect on colon cancer cells mediated by the upregulation of CXCR4 on the cell surface.

after the publication of the article, it has been brought to the authors' attention by an interested reader that we had made an error regarding the colon cancer cell line in the manuscript. The error relates to Materials and methods, as well as Results, the colon cancer cell line in the Transwell migration assay and Flow cytometric detection of CxCR4 expression is hCT-116 rather than SW620. accordingly, the correct legends in Figs. 3 and 6 in the paper are hCT-116 cells. This error does not affect the overall conclusions reported in the present study. We sincerely apologize for this mistake, and thank the reader of our article who drew this matter to our attention. Furthermore, we regret any inconvenience this error may have caused.