Endostatin induces normalization of blood vessels in colorectal cancer and promotes infiltration of CD8+ T cells to improve anti-PD-L1 immunotherapy.

Introduction: The purpose of this study was to evaluate recombinant human endostatin (rHE)-induced normalization of the tumor vasculature in colorectal cancer (CRC) and to evaluate the therapeutic effects of combined treatment with rHE and a programmed death ligand-1 (PD-L1) inhibitor. Methods: A mouse subcutaneous tumorigenesis model was established to evaluate the antitumor effects of endostatin combined with a PD-L1 inhibitor on CRC. Intravoxel incoherent motion diffusion-weighted magnetic resonance imaging (IVIM-DW MRI) was used to evaluate changes in the intratumor microcirculation in response to combined treatment with endostatin and a PD-L1 inhibitor. The infiltration density and function of CD8+ T cells in tumors were evaluated using flow cytometry. Finally, clinical specimens were used to evaluate the expression area of tumor vascular pericytes and CD8+ T cells in tumor tissues. Results: The antitumor effects of endostatin combined with a PD-L1 inhibitor were significantly greater than those of endostatin or a PD-L1 inhibitor alone. On the ninth day of intervention, the endostatin group showed significantly higher pseudo diffusion parameter (D*) and microvascular volume fraction (F) values in tumors than those in the control group or PD-L1 group. After 27 days of intervention, the endostatin groups showed significantly lower levels of vascular endothelial growth factor (VEGF) and transforming growth factor (TGF)-ß than those in the control group. Treatment of CD8+ T cells with endostatin for 24 h did not alter the expression levels of markers of reduced T-cell activity. However, endostatin reversed the VEGF-mediated inhibition of the secretion of interferon (IFN)-γ from T cells. The results in CRC clinical samples showed that treatment with endostatin induced significantly higher infiltration of CD8+ T cells compared with treatment that did not include endostatin. Furthermore, the expression area of pericytes was significantly positively related to the infiltration density of CD8+ T cells and overall survival time. Conclusion: Endostatin improved the antitumor effects of PD-L1 inhibitors on CRC, significantly increased the activity of CD8+ T cells, and synergistically improved the tumor treatment effect of the two inhibitors.

Thrombospondin-2 holds prognostic value and is associated with metastasis and the mismatch repair process in gastric cancer.

BACKGROUND: This study aims to investigate thrombospondin 2 (TSP2) expression levels in gastric cancer (GC) and determine the relationship between TSP2 and clinical characteristics and prognosis. METHODS: The online database Gene Expression Profile Interactive Analysis (GEPIA) was used to analyse TSP2 mRNA expression levels in GC. The Kaplan-Meier plotter prognostic analysis tool was used to evaluate the influence of TSP2 expression on clinical prognosis in GC patients. TSP2 expression levels were analysed in paraffin-embedded GC samples and adjacent normal tissues by immunohistochemistry. The relationship between the clinicopathological characteristics and prognosis of GC patients was assessed. Transwell experiments were used to evaluate the effect of TSP2 on HGC27 and AGS cell invasion and migration. The EdU experiment was used to detect the effect of transfection of TSP2 on cell proliferation, and the flow cytometry experiment was used to detect the effect of TSP2 on cell apoptosis and the cell growth cycle. Western blotting (Wb) technology was used to detect MMP, E-cadherin, N-cadherin, Vimentin, Snail, AKT, PI3K, and VEGF protein expression in HGC27 cells. RESULTS: Compared with normal tissues, TSP2 mRNA expression in GC was significantly upregulated and was closely related to the clinical stage of GC. High TSP2 expression significantly affected the OS, FP and PPS of patients with GC. Among these patients, TSP2 expression levels did not affect the prognosis of patients with GC in the N0 subgroup but significantly affected the prognosis of patients with GC in the N (1 + 2 + 3) subgroup. TSP2 protein expression levels were significantly higher in GC tissue compared with normal tissues (P < 0.01). The overall survival (OS) and relapse-free survival (RFS) of patients with high TSP2 expression were lower than those of patients with low TSP2 expression. Cells transfected with the TSP2-silencing sequence exhibited increased apoptosis and inhibition of proliferation, migration and invasion. AKT and PI3K expression in cells was significantly downregulated (P < 0.01). AKT, PI3K and VEGF expression in cells transfected with the TSP2 silencing sequence was significantly reduced. Proliferation, migration, invasion ability, and TSP2 expression levels significantly correlated with mismatch repair genes, such as PMS2, MSH6, MSH2, and MLH1 (P < 0.05). CONCLUSION: TSP2 expression is significantly increased in GC. TSP2 expression is closely related to metastasis and the mismatch repair process in GC patients and affects GC patient prognosis. The mechanism may involve regulating gastric cancer cell proliferation and migration by modulating the VEGF/PI3K/AKT signalling pathway. TSP2 is a potential marker and therapeutic target for the prognosis of GC patients.

Clinicopathological and prognostic significance of Fusobacterium nucleatum infection in colorectal cancer: a meta-analysis.

Background: This study aimed to clarify the relationship between F. nucleatum levels and the prognosis of CRC, which is still controversial. Methods: Relevant articles were searched on PubMed, Web of Science, PMC and Embase up to April 7, 2020. Outcomes of interest included clinical characteristics, molecular characteristic and survival analysis. HR (OR), odds ratios (OR) and 95% confidence interval (CI) were calculated to explore the prognostic value and relationship of clinical characteristics of Fusobacterium nucleatum in CRC. Results: A total of 3626 CRC patients from 13 eligible studies were included. High levels of F. nucleatum were associated with worse prognosis, as such parameters as overall survival (OS) (hazard ratio [HR] = 1.40, 95% confidence interval [CI]: 1.40 - 1.63, P < 0.0001), disease-free survival (DFS) (HR = 1.71, 95% CI: 1.29-2.26, P = 0.0002), and cancer-specific survival (OR= 1.93, 95% CI: 1.42-2.62, P <0.0001). F. nucleatum levels were related with T3-T4 stage (OR = 2.20, 95% CI: 1.66-2.91, P < 0.00001), M1 stage (OR = 2.11, 95% CI: 1.25-3.56, P = 0.005), poor tumor differentiation (OR = 1.83, 95% CI: 1.11-3.03, P =0.02), microsatellite instability-high (OR = 2.53, 95% CI: 1.53-4.20, P = 0.0003), and KRAS mutation (OR =1.27, 95% CI: 1.00-1.61, P=0.05) showed. Conclusions: High levels of F. nucleatum suggest a poor prognosis and are associated with tumor growth, distant metastasis, poor differentiation, MSI-high, and KRAS mutation in CRC patients.

A network pharmacology approach for investigating the multi-target mechanisms of Huangqi in the treatment of colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) is the third most prevalent cancer globally. In the treatment of CRC, surgical resection is commonly adopted, and neoadjuvant chemotherapy or immunotherapy is mainly administered for patients with advanced disease. However, despite the developments in the field of cancer treatment, the mortality rate of CRC has remained high. Therefore, novel treatments for CRC need to be explored. Astragalus membranaceus, commonly known in China as Huangqi (HQ), a traditional Chinese medicine, has been reported to be a potential antitumorigenic agent. This study aimed to investigate the mechanisms of action of HQ. METHODS: Active ingredients and putative targets of HQ were obtained through a comprehensive search of the Traditional Chinese Medicine Systems Pharmacology database. CRC-related targets were retrieved from the GeneCards database and then overlapping targets were acquired. After visualization of the compound-disease network and protein-protein interaction (PPI) network, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses of the overlapping genes were performed. Additionally, HCT116 cells were treated with the active components of HQ at a 20-µM concentration. Cell Counting Kit-8 was used to detect cell activity, and real-time quantitative polymerase chain reaction was carried out to detect the expression of genes downstream of the interleukin (IL)-17 signaling pathway. RESULTS: A PPI network comprising 177 nodes and 318 edges was obtained. The GO analysis of the overlapping genes showed enrichment in response to lipopolysaccharide and oxidative process. For the KEGG analysis, the AGE-RAGE signaling pathway and inflammation-related pathways, such as the IL-17 and tumor necrosis factor (TNF) signaling pathways, were enriched. The in vitro experiments showed that HQ promoted the apoptosis of CRC cells by inhibiting the expression of the CCL2, CXCL8, CXCL10, and PTGS2 genes. CONCLUSIONS: This study systematically revealed the multitarget mechanism of HQ in CRC through a network pharmacology approach. We verified that HQ promotes CRC cell death via the IL-17 signaling pathway. This finding provides indications for further mechanistic studies and the development of HQ as a potential treatment for CRC patients.