Background/Aims This study aimed to explore the effect of gut microbiota-regulated Kupffer cells (KCs) on colorectal cancer (CRC) liver metastasis. Methods A series of in vivo and in vitro researches were showed to demonstrate the gut microbiota and its possible mechanism in CRC liver metastasis. Results Fewer liver metastases were identified in the ampicillin-streptomycin-colistin and colistin groups. Increased proportions of Parabacteroides goldsteinii , Bacteroides vulgatus , Bacteroides thetaiotaomicron , and Bacteroides uniformis were observed in the colistin group. The significant expansion of KCs was identified in the ampicillin-streptomycin-colistin and colistin groups. B. vulgatus levels were positively correlated with KC levels. More liver metastases were observed in the vancomycin group. An increased abundance of Parabacteroides distasonis and Proteus mirabilis and an obvious reduction of KCs were noted in the vancomycin group. P. mirabilis levels were negatively related to KC levels. The number of liver metastatic nodules was increased in the P. mirabilis group and decreased in the B. vulgatus group. The number of KCs decreased in the P. mirabilis group and increased in the B. vulgatus group. In vitro , as P. mirabilis or B. vulgatus doses increased, there was an opposite effect on KC proliferation in dose- and time-dependent manners. P. mirabilis induced CT26 cell migration by controlling KC proliferation, whereas B. vulgatus prevented this migration. Conclusions An increased abundance of P. mirabilis and decreased amount of B. vulgatus play key roles in CRC liver metastasis, which might be related to KC reductions in the liver.

Abstract. It remains unknown whether blockade of B-Raf proto-oncogene, serine/threonine kinase (BRAF) V600E signaling and MET proto-oncogene, receptor tyrosine kinase (c-Met) signaling is effective in suppressing the growth of human colorectal cancer (CRC) cells. The present study investigated the effects of the vemurafenib alone and in combination with c-Met inhibitor PHA-665752 on the growth of human CRC cells in vitro and in mouse xenografts. HT-29 and RKO CRC cell lines with BRAF V600E mutations and mice bearing HT-29 xenografts were treated with vemurafenib in the absence or presence of PHA-665752. Cell viability and cycle phase were respectively examined by using the MTT and flow cytometry assay. Immunohistochemistry was conducted to detect the protein expression levels of hepatocyte growth factor (HGF), phosphorylated (p)-c-Met, p-AKT serine/threonine kinase (AKT) and p-extracellular signal-regulated kinase (p-ERK). The MTT assay demonstrated that the growth of RKO and HT-29 cells was inhibited by PHA-665752 in a time-and dose-dependent manner (P<0.05), however no significant suppressive effects were observed with vemurafenib. Relative to the PHA-665752 or vemurafenib stand-alone treatment groups, the combination of PHA-665752 and vemurafenib had a significant inhibitory effect on the proliferation of CRC cell lines (P<0.05). The mean tumor volume in mice treated with vemurafenib in combination with PHA-665752 was significantly smaller compared with those treated with only vemurafenib or PHA-665752 (P<0.05). Flow cytometry assay revealed that the G0/G1 phase frequency was significantly increased in the combination group compared with any other treatment groups (P<0.05). Immunohistochemistry demonstrated that vemurafenib in combination with PHA-665752 effectively induced the expression of p-c-Met, p-AKT and p-ERK, however had no effect on HGF. IntroductionColorectal cancer (CRC) is one of the principal causes of cancer worldwide (1). Unfortunately, even if a 5-year survival prognosis can be given to 90% of patients in the early stages, disappointing treatment outcomes are recorded in subjects with extensive local invasion or distant metastases. Generally, their 5-year survival rate is less than 15% (2) and, even if suitable for receiving adjuvant chemotherapy, disease-related deaths remain stubbornly high.A recent steady stream of important breakthroughs has dramatically improved our understanding of CRC. One such discovery identified the BRAF mutation as common in metastatic CRC patients, especially those with a right-side colon cancer and a poorly differentiated tumor (3). Vemurafenib is a potent and selective inhibitor of mutated BRAF. Chapman et al (4) revealed that vemurafenib achieved 40% response rates in melanoma with a BRAF mutation. However, unlike melanoma, the effect of vemurafenib in CRC patients with a BRAF mutation is often negligible, resulting in a clinical response in only 5% of patients (5). This discrepancy of outcomes suggests that different cancer types may present important variat...

Background. Fatigue is a common, distressing, and persistent symptom for patients with malignant tumor including colorectal cancer (CRC). Although studies of cancer-related fatigue (CRF) have sprung out in recent years, the pathophysiological mechanisms that induce CRF remain unclear, and effective therapeutic interventions have yet to be established. Methods. To investigate the effect of the traditional Chinese medicine YangZheng XiaoJi (YZXJ) on CRF, we constructed orthotopic colon cancer mice, randomly divided into YZXJ group and control (NS) group. Physical or mental fatigue was respectively assessed by swimming exhaustion time or suspension tail resting time. At the end of the experiment, serum was collected to measure the expression level of inflammatory factors by ELISA and feces to microbiota changes by 16s rDNA, and hepatic glycogen content was detected via the anthrone method. Result. The nutritional status of the YZXJ group was better than that of the control group, and there was no statistical difference in tumor weight. The swimming exhaustion times of YZXJ group and control group were (162.80 ± 14.67) s and (117.60 ± 13.42, P < 0.05) s, respectively; the suspension tail resting time of YZXJ group was shorter than that of the control group (49.85 ± 4.56) s and (68.83 ± 7.26) s, P < 0.05)). Serum levels of IL-1β and IL-6 in YZXJ group were significantly lower than the control group (P < 0.05). Liver glycogen in YZXJ group was (5.18 ± 3.11) mg/g liver tissue, which was significantly higher than that in control group (2.95 ± 2.06) mg/g liver tissue (P < 0.05). At phylum level, increased abundance of Bacteroidetes, Verrucomicrobia, Actinobacteria, and Cyanobacteria and decreased Proteobacteria in YZXJ group emerged as the top differences between the two groups, and the Firmicutes/Bacteroidetes ratio was decreased in YZXJ group compared to the control group. At genus level, the abundance of Parabacteroides, unidentified Saprospiraceae, and Elizabethkingia which all belong to phylum Bacteroidetes were increased, while Arcobacter, Marinobacter, Alkanindiges, Sulfuricurvum, Haliangium, and Thiobacillus in phylum Proteobacteria were decreased after YZXJ intervention. YZXJ can also increase Pirellula, Microbacterium, and Alpinimonas and decrease Rubrobacter and Iamia. Conclusion. YZXJ may reduce the physical and mental fatigue caused by colorectal cancer by inhibiting inflammatory reaction, promoting hepatic glycogen synthesis, and changing the composition of intestinal microbiota.

Combination treatment with PHA-665752 and cetuximab suppressed in vitro and in vivo CRC cell growth more than treatment with either agent alone did.

Background: The gut microbiota regulates the liver immune microenvironment in colorectal cancer (CRC) through gut-liver axis. Kupffer cells (KCs) contribute significantly to the formation of pre-metastatic niches (PMNs) for CRC liver metastasis. The aim of our study was to explore the effect of gut microbiota regulating KCs in CRC liver metastasis. Results: Mice treated with different antibiotics were divided into Control group, vancomycin (Vanc) group, colistin (Coli) group, and a group of ampicillin, streptomycin and colistin (ASC). Fewer liver metastases were identified in mice in the ASC group and Coli group than in those in the Control group (P = 0.003, P = 0.041, respectively). An increased proportion of Parabacteroides_goldsteinii, Bacteroides_vulgatus, Bacteroides_ thetaiotaomicron, Bacteroides_uniformis in mice of the Coli group were observed in 16S rDNA sequencing. Consistent with the Tax4Fun functional prediction, a prominent expansion of hepatic KCs was identified in mice in the ASC and Coli groups compared to those in the Control group (P = 0.001, P = 0.038, separately). Meanwhile, Bacteroides_vulgatus was a positive correlation with KCs contents (P = 0.011, r = 0.705). On the other hand, more liver metastases were observed in mice of the Vanc group than those in the Control group (P = 0.028). An increased abundance of Parabacteroides_distasonis, Proteus_mirabilis and a remarkable reduction of hepatic KCs were observed in mice in the Vanc group (P = 0.027). Pearson correlation analysis showed Proteus_mirabilis was a negative related to KCs contents (P = 0.028, r = 0.632). Conclusions: An increased abundance of Proteus_mirabilis and a decreased abundance of Bacteroides_vulgatus may be a key factor in CRC liver metastasis, which may be related to the reduction of KCs in the liver.