Differences in tissue-associated bacteria between metastatic and non-metastatic colorectal cancer.

Background and aims: Accumulated evidence indicates that the intestinal microbiota plays crucial roles in the initiation and progression of colorectal cancer (CRC). However, the effects of the tissue-associated microbiota on CRC metastasis are poorly defined. The aim of this study was to explore the differences in bacteria between metastatic and non-metastatic CRC tissues and identify potential bacterial species that associate with CRC metastasis. Methods: 16S rDNA amplicon high-throughput sequencing was used to test the intestinal tissue-associated microbiota in patients with metastatic CRC (n = 48) and non-metastatic CRC (n = 44). The microbial diversity and differential species were analysed by standard microbiological methods, and then the differential bacteria were confirmed by qPCR. Receiver operating characteristic (ROC) curves were plotted to evaluate the ability of the differential bacteria in predicting the metastasis of CRC. In addition, the microbial compositions of tumor-adjacent tissues from the metastatic and non-metastatic CRC groups were analysed. Results: The α- or ß-diversity of microbial community between the metastatic and non-metastatic CRC groups did not exhibit significant differences. However, some bacterial abundances between two groups showed significant differences. At the phylum level, Bacteroidota and Desulfobacterota were significantly higher in the metastatic group than in the non-metastatic group, while Proteobacteria was significantly decreased in the metastatic group. At the genus level, Bacteroides (mainly composed of Bacteroides fragilis and Bacteroides uniformis) was significantly higher in the metastatic group than in the non-metastatic group, while Streptococcus and Escherichia-Shigella were significantly decreased. The ROC curves of the selected bacteria showed area under the curve (AUC) values ranging from 0.598 to 0.69; when CEA and the selected bacteria were combined, the AUC values increased from 0.678 to 0.705. In addition, the bacterial composition of tumor-adjacent tissues from the metastatic and non-metastatic CRC groups were also different, and the differential bacteria were consistent with those between metastatic and non-metastatic CRC tumor tissues. Conclusion: The bacterial composition of tumor and tumor adjacent tissue from the metastatic CRC group was different from that of the non-metastatic CRC group; in particular, Bacteroides was increased, and Streptococcus was decreased. These findings are helpful to further reveal the mechanism of CRC metastasis and provide new ideas for the clinical diagnosis and treatment of CRC metastasis.

Prophylactic chemotherapeutic hyperthermic intraperitoneal perfusion reduces peritoneal metastasis in gastric cancer: a retrospective clinical study.

BACKGROUND: Peritoneal metastasis is the most frequent failure in gastric cancer. This study evaluated the role of prophylactic chemotherapeutic hyperthermic intraperitoneal perfusion (CHIP) in patients after D2 dissection. METHODS: Gastric cancer patients after D2 dissection were enrolled in this study. Patients received either chemotherapy (IV group) or CHIP (CHIP group). Sites of recurrence or metastasis, disease-free survival (DFS), overall survival (OS) and adverse events were evaluated. RESULTS: Twenty-two patients received CHIP treatment, and 21 patients received chemotherapy alone. The median DFS time was 24.5 and 36.5 months in the IV group and CHIP group (P = 0.044), respectively. The median OS time was 33.1 months in the IV group and not reached in the CHIP group (P = 0.037). We also found that CHIP could reduce the total recurrence/metastasis rate, especially that of peritoneal metastasis. In the subgroup analysis, DFS and OS were both superior in deficient mismatch repair (dMMR) patients than in proficient MMR (pMMR) patients. CONCLUSION: This hypothesis-generating study indicates that CHIP might be feasible for gastric cancer patients after D2 resection.

LARP1 is regulated by the XIST/miR-374a axis and functions as an oncogene in non-small cell lung carcinoma.

La-related protein 1 (LARP1) is a conserved RNA-binding protein and is known to regulate 5'-terminal oligopyrimidine tract (TOP) mRNA translation. Dysregulated LARP1 has been reported to be related to the development of several cancers. However, the exact function and mechanism of LARP1 in non-small cell lung cancer (NSCLC) is largely unknown. In the present study, we found that the mRNA levels of LARP1 were increased in NSCLC cells compared to those in normal control cells. Knockdown of LARP1 inhibited cell proliferation, migration and invasion in NSCLC cells and tumourigenicity in H520 cells. Both in vitro and in vivo analyses confirmed that STAT3 signalling was inactivated by the knockdown of LARP1. Moreover, LARP1 was identified as a direct target of miR-374a. Overexpression of miR-374a attenuated the promotor effects of LARP1 by inhibiting proliferation, metastasis and STAT3 signalling. Clinically, LARP1 was markedly overexpressed in NSCLC tissues, and upregulated LARP1 was correlated with tumour progression and poor survival. The expression of miR-374a was negatively correlated with the expression of LARP1 in NSCLC tissues. Furthermore, we found that XIST functioned as a competing endogenous RNA to suppress miR-374a, which regulated its downstream target LARP1. In summary, we suggest that the dysfunction of the XIST/miR-374a/LARP1 axis contributes to NSCLC and may serve as a promising therapeutic strategy for treatment.