Liang Shi

HMGB1 recruits myeloid derived suppressor cells to promote peritoneal dissemination of colon cancer after resection

Peritoneal metastasis of colorectal cancer is a major clinical issue and results in poor prognosis for patients after surgical resection. Here, we found that abdominal surgery trauma induced high release of high-mobility group box 1 (HMGB1) in the peritoneal cavity of mice. Recombinant HMGB1 injected in the peritoneal cavity recruited abundant myeloid derived suppressor cells (MDSCs) after the surgical trauma. HMGB1 Box-A and gemcitabine reduced the recruitment of MDSCs in the peritoneal cavity after the operation and ameliorated the peritoneal metastasis burden of colon cancer in mouse model. These results showed that abdominal surgery trauma leads to a large amount of HMGB1 released in the peritoneal cavity which recruits numerous MDSCs to promote peritoneal metastasis of colon cancer after curative surgery.

Maresin 1, a Proresolving Lipid Mediator, Mitigates Carbon Tetrachloride-Induced Liver Injury in Mice

Maresin 1 (MaR 1) was recently reported to have protective properties in several different animal models of acute inflammation by inhibiting inflammatory response. However, its function in acute liver injury is still unknown. To address this question, we induced liver injury in BALB/c mice with intraperitoneal injection of carbon tetrachloride with or without treatment of MaR 1. Our data showed that MaR 1 attenuated hepatic injury, oxidative stress, and lipid peroxidation induced by carbon tetrachloride, as evidenced by increased thiobarbituric acid reactive substances and reactive oxygen species levels were inhibited by treatment of MaR 1. Furthermore, MaR 1 increased activities of antioxidative mediators in carbon tetrachloride-treated mice liver. MaR 1 decreased indices of inflammatory mediators such as tumor necrosis factor-α, interleukin-6, interleukin-1β, monocyte chemotactic protein 1, myeloperoxidase, cyclooxygenase-2, and inducible nitric oxide synthase. Administration of MaR 1 inhibited activation of nuclear factor kappa B (NF-κb) and mitogen-activated protein kinases (MAPKs) in the liver of CCl4 treated mice. In conclusion, these results suggested the antioxidative, anti-inflammatory properties of MaR 1 in CCl4 induced liver injury. The possible mechanism is partly implicated in its abilities to inhibit ROS generation and activation of NF-κb and MAPK pathway.

miR-219-5p plays a tumor suppressive role in colon cancer by targeting oncogene Sall4

Sall4 is a novel oncogene found upregulated in several malignancies including colon cancer. However, its upstream regulatory miRNA is still undefined. miR-219-5p is regarded as a tumor-related miRNA in cancer research. Nevertheless, its actual role of whether inhibiting or promoting tumorigenesis is unclear in colon cancer. Potential interaction between Sall4 and miR-219-5p is predicted by TargetScan. CCK-8 test was used for evaluation of cell proliferation and cell survival rates. Western blot analysis and real-time PCR were applied for detection of target molecules. Luciferase assay was a direct confirmation of mutual interaction. Wound healing assay and transwell assay were conducted for cell migration and invasion tests. Flow cytometry was used for cell apoptosis analysis. Tissue specimens and cell lines were explored for miR-219-5p inhibition on colon cancer proliferation, migration, invasion, apoptosis and drug resistance by targeting Sall4. The results show that miR-219-5p inhibited carcinogenesis of colon cancer by targeting oncogene Sall4.

Co-expression of TIM-3 and CEACAM1 promotes T cell exhaustion in colorectal cancer patients

&NA; T‐cell immunoglobulin domain and mucin domain‐3(TIM‐3) is an activation induced inhibitory molecule involved in immune tolerance and is recently reported to induce T cell exhaustion which is mediated by carcinoembryonic antigen cell adhesion molecule 1(CEACAM1), another well‐known molecule expressed on activated T cells and involved in T cell inhibition. To investigate the expression of TIM‐3 and CEACAM1 on circulating CD8+ T cells and tumor infiltrating lymphocytes (TILs), 65 diagnosed colorectal cancer (CRC) patients and 38 healthy controls were enrolled in this study and the results showed that TIM‐3 and CEACAM1 were both highly expressed on circulating CD8+ T cells in CRC patients and elevated on TILs compared with paraneoplastic T cells. Furthermore, TIM‐3+ CEACAM1+ CD8+ T cells represented the most dysfunctional population with the least IFN‐&ggr; production. In addition, the expressions of TIM‐3 and CEACAM1 were correlated with advanced stage and could be independent risk factors for CRC. We for the first time to our knowledge suggested that co‐expression of TIM‐3 and CEACAM1 can mediate T cell exhaustion and may be potential biomarkers for CRC prediction, highlighting the possibility of being immunotherapy targets. HighlightsIdentification of two potential immuno‐markers for colorectal cancer.Their co‐expression mediates T cell exhaustion and promotes cancer progression.The connection between markers and clinical features implies for targeted therapy.

Role of IL-17 and TGF-β in peritoneal adhesion formation after surgical trauma

Peritoneal adhesions are fibrous tissues formed after surgery. Both cytokines and transforming growth factors (TGFs) are involved in this process. The objective of this study was to investigate the cross talk between these entities. Peritoneal drainage fluid after surgery from patients and rodent models was examined by enzyme‐linked immunosorbent assay and fluorescence‐activated cell sorter. Data showed that the concentrations of interferon (IFN)‐γ and interleukin (IL)‐17 reached their peaks 6–12 hours after surgery, whereas TGF‐β1 concentrations showed two postoperative peak time points at 2 and 72–96 hours. By neutralizing IFN‐γ, IL‐17 6–12 hours, and TGF‐β1 72–96 hours after surgery, the degree of adhesion reduced significantly. However, neutralizing TGF‐β1 2 hours after surgery did not affect adhesion formation. Furthermore, in vitro studies showed that compared with the fibroblasts that were directly stimulated with TGF‐β1, the prestimulation of IL‐17 promoted plasminogen activator inhibitor‐1 production while inhibiting tissue‐type plasminogen activator production. Moreover, additional stimulation with IFN‐γ enhanced this effect. Together, these data indicate that IL‐17 may promote adhesion formation by increasing the reaction of fibroblasts against TGF‐β1. Blocking IL‐17 might have a therapeutic potential in preventing adhesion formation after surgery.

Helicobacter Pylori Promote B7-H1 Expression by Suppressing miR-152 and miR-200b in Gastric Cancer Cells

The most common cause of gastric cancer is infection with helicobacter pylori (HP), but the associated molecular mechanism is not well understood. In the present study, we found a marked increase in the expression of B7-H1, a member of the B7 co-stimulatory family of molecules that bind to programmed death-1 (PD-1) and play a critical immunoregulatory role in the cell-mediated immune response, in HP-positive gastric cancer tissue. Infection of cultured gastric cancer cells with HP promoted B7-H1 expression and inhibited miR-152 and miR-200b expression. We further demonstrated that these two miRNAs targeted B7-H1 mRNA and suppressed B7-H1 expression in gastric cancer cells. Finally, B7-H1 expression was found to correlate with miR-152 and miR-200b levels in gastric tumor tissues from human patients. Our findings suggest a novel mechanism by which HP infection promotes gastric cancer and also suggest potential targets, i.e., miR-152 and miR-200b, for the prevention and treatment of gastric cancer.

Siglec-10 is associated with survival and natural killer cell dysfunction in hepatocellular carcinoma

BACKGROUND The interaction between Siglec-10 and its ligand, CD24, selectively represses tissue damage-caused immune responses. However, the nature of Siglec-10 and CD24 in human hepatocellular carcinoma (HCC) is still poorly defined. Hereon, the expression, function, and regulation of CD24 and Siglec-10 in HCC were investigated in the present study. METHODS Flow cytometry was performed to examine the expression of Siglec-10 in HCC tissues and adjacent non-tumor tissues of HCC patients. To further determine whether Siglec-10 expression is associated with the clinical characteristics and survival, conventional immunohistochemistry was performed in 96 HCC patients. Additionally, the role of Siglec-10 in the regulation of natural killer (NK) cell dysfunction was evaluated. Finally, CD24 expression in HCC was also assessed. RESULTS Siglec-10 was expressed most on NK cells in HCC (40.7 ± 4.5%). Compared with surrounding non-tumor tissues, tumor tissues had higher Siglec-10 expression (31.0 ± 1.7% versus 40.7 ± 4.5%, n = 10, P < 0.05), and the expression was negatively associated with patient survival. Siglec-10(+)CD56(+) NK cells exhibited reduced effector function, as shown by decreased granules and cytokine expressions compared with Siglec-10(-)CD56(+) NK cells. Moreover, the number of CD24(+)CD45(-) cells in HCC tissues was higher than that in adjacent non-tumor tissues (9.4 ± 0.9% versus 3.1 ± 0.9%, n = 15, P < 0.05). CONCLUSIONS These findings suggest that Siglec-10 is associated with decreased survival and impaired NK cell function in human HCC. This process may function via the CD24-Siglec-10 interaction, which may represent a therapeutic target in HCC patients.

Omental adipocytes enhance the invasiveness of gastric cancer cells by oleic acid-induced activation of the PI3K-Akt signaling pathway.

A considerable number of patients with advanced gastric cancer have a clear predilection for metastasis to the great omentum, an organ mainly composed of adipose tissue. However, it remains unclear why tumor cells preferentially spread to and progress in the omentum. Here, we used a two-dimensional co-culture system to simulate the crosstalk between adipocytes and gastric cancer cells and showed that after co-culture with isolated omental adipocytes, gastric cancer cells exhibited a significant increase in lipid uptake and enhanced invasiveness. A lipidomic study showed that gastric cancer cells accumulated higher levels of oleic acid during the co-culture. By performing an assay of key enzymes in lipid synthesis, we demonstrated that the increased amount of oleic acid in gastric cancer cells mainly came from the adjacent adipocytes in the co-culture system. Furthermore, our data showed that at a certain concentration range, oleic acid treatment enhanced the invasiveness of gastric cancer cells in vitro and in a CAM assay, through the PI3K/Akt pathway, with the associated increased expression of the key pro-invasion factor MMP-2. Taken together, our results demonstrated that adipocytes may serve as an exogenous source of oleic acid that promotes gastric cancer cell invasion through the PI3K/Akt signaling pathway.

Prognostic Significance of the Metabolic Marker Hexokinase-2 in Various Solid Tumors: A Meta-Analysis

Objective Recently, numerous studies have reported that hexokinase-2 (HK2) is aberrantly expressed in cancer, indicating that HK2 plays a pivotal role in the development and progression of cancer. However, its prognostic significance in solid tumor remains unclear. Accordingly, we performed a meta-analysis to assess the prognostic value of HK2 in solid tumor. Methods Eligible studies were identified using PubMed, Embase, and Web of Science databases. Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) for overall survival (OS) or progression-free survival (PFS)/disease-free survival (DFS)/relapse-free survival (RFS) were estimated with random effects or fixed effects models, respectively. Subgroup analysis was also performed according to patients’ ethnicities, tumor types, detection methods, and analysis types. Results Data from 21 included studies with 2532 patients were summarized. HK2 overexpression was significantly associated with worse OS (pooled HR = 1.90, 95% CI = 1.51–2.38, p < 0.001) and PFS (pooled HR = 2.91, 95% CI = 2.02–4.22, p < 0.001) in solid tumor. As to a specific form of cancer, the negative effect of HK2 on OS was observed in hepatocellular carcinoma (pooled HR = 2.06, 95% CI = 1.67–2.54, p < 0.001), gastric cancer (pooled HR = 1.72, 95% CI = 1.09–2.71, p = 0.020), colorectal cancer (pooled HR = 2.89, 95% CI = 1.62–5.16, p < 0.001), but not in pancreatic cancer (pooled HR = 1.13, 95% CI = 0.28–4.66, p = 0.864). No publication bias was found in the included studies for OS (Begg’s test, p = 0.325; Egger’s test, p = 0.441). Conclusion In this meta-analysis, we identified that elevated HK2 expression was significantly associated with shorter OS and PFS in patients with solid tumor, but the association varies according to cancer type.

Reduced proliferation and increased apoptosis of the SGC‑7901 gastric cancer cell line on exposure to GDC‑0449

The sonic hedgehog (Shh) pathway is known to be vital in embryonic development and cancer propagation due to its irreplaceable role in cell proliferation and differentiation. GDC‑0449, a basal cell skin cancer target drug approved by the Food and Drugs Administration, is a smoothened (Smo)-specific antagonist. Although it has been clinically verified as a valid drug for the treatment of skin and pancreatic cancer, the application of GDC‑0449 in gastric cancer requires further investigation. In the present study, high-glucose Dulbeccos modified Eagles medium with 10% fetal bovine serum was used for routine SGC‑7901 cell line culture. A Cell Counting Kit‑8 assay was employed for determination of the reproductive rate of the cells. Flow cytometry was performed to determine the apoptosis status of the SGC‑7901 cell line through Q4 analysis. Reverse transcription-quantitative polymerase chain reaction and Western blot analyses were used as target molecule detection vehicles. As expected, GDC‑0449 reduced the expression levels of Shh‑associated molecules, including Smo and gli1, compared with the blank group. The rate of cell proliferation was markedly limited and was accompanied by an increase in the apoptotic rate following GDC‑0449 exposure. In addition, further investigations confirmed B cell lymphoma‑2 (Bcl‑2) as the downstream molecular mechanism of GDC‑0449 efficacy. Of note, representatives of the cancer stem cell (CSC) surface marker, CD44 and CD133, demonstrated a similar trend to the Smo restriction observed. By repressing the expression of Bcl‑2, GDC‑0449 inhibited the normal proliferation of SGC‑7901 cells, and accelerated the apoptotic rate of the cells. It may also alter CSC properties due to the reduction in the expression of surface markers.