Tumor cell-secreted exosomal miR-22-3p inhibits transgelin and induces vascular abnormalization to promote tumor budding.

Tumor budding (TB) is considered a histomorphological marker of poor prognosis in patients with breast cancer (BC). Tumor vasculature is disordered and unstable in BC, which causes restricted drug delivery, hypoxia, and tumor metastasis. Traditional anti-angiogenic treatments cause extreme hypoxia, increased invasion, metastasis, and drug resistance due to blood vessel rarefaction or regression. Therefore, the application of anti-angiogenic strategies for vascular normalization in tumors is crucial to improve therapeutic efficacy in BC. In the present study, we found that transgelin (TAGLN) promoted the normalization of tumor vessels by regulating the structure and function of endothelial cells, and knockout of TAGLN in tumor-bearing mice resulted in tumor vessel abnormalization, an increase in epithelial-mesenchymal transition characteristics of tumor cells, and promotion of TB. Moreover, BC cells secrete exosomal miR-22-3p that mediates tumor vessel abnormalization by inhibiting TAGLN. We demonstrated for the first time that TAGLN plays an essential role in tumor vessel normalization, and thus it impairs TB and metastasis. Additionally, the findings of this study indicate that exosomal miR-22-3p is a potential therapeutic target for BC.

Correction: Interaction between laminin-5γ2 and integrin ß1 promotes the tumor budding of colorectal cancer via the activation of Yes-associated proteins.

The original version of this Article contained an error in the author affiliations. Affiliation number 4 incorrectly read "Department of Gastroenterology and Hepatology, Tianjin Institute of Digestive Disease, Tianjin Institute of Digestive Disease". It should be "Department of Gastroenterology and Hepatology, Tianjin Medical University General Hospital, Tianjin Medical University, Tianjin 300052, China".

Interaction between laminin-5γ2 and integrin ß1 promotes the tumor budding of colorectal cancer via the activation of Yes-associated proteins.

Colorectal cancer (CRC) is a common cancer type and a threat to human health. Tumor budding (TB) is the presence of a single cancer cell or clusters of up to five cancer cells prior to the invasive front of an aggressive carcinoma and is an independent prognosis factor for CRC. The molecular mechanism of TB is still unclear, and drugs that inhibit this process are still in the blank stage. This study found that TBs exhibit characteristics of partial EMT with a decreased expression of E-cadherin and no substantial differences in the expression of N-cadherin and vimentin. We also observed the interaction of integrin with extracellular matrix components, laminin-5γ2 (LN-5γ2), play essential roles in the TB of CRC. We then verified that the interaction between LN-5γ2 and integrin ß1 promotes the TB of CRC via the activation of FAK and Yes-associated proteins (YAP). A natural drug monomer, cucurbitacin B, was screened using virtual screening methods for the interaction interface of proteins. We found that this monomer could block the interaction interface between LN-5γ2 and integrin ß1 and substantially inhibit the TB of CRC cells via inactivation of YAP. This study provides new insights into the mechanism of TB mechanism and the development of drugs targeting the TB of CRC.

Therapeutic effects of lentinan on inflammatory bowel disease and colitis-associated cancer.

In this study, we investigated the therapeutic potential of lentinan in mouse models of inflammatory bowel disease (IBD) and colitis-associated cancer (CAC). Lentinan decreased the disease activity index and macroscopic and microscopic colon tissue damage in dextran sulphate sodium (DSS)-induced or TNBS-induced models of colitis. High-dose lentinan was more effective than salicylazosulfapyridine in the mouse models of colitis. Lentinan decreased the number of tumours, inflammatory cell infiltration, atypical hyperplasia and nuclear atypia in azoxymethane/DSS-induced CAC model. It also decreased the expression of pro-inflammatory cytokines, such as IL-13 and CD30L, in IBD and CAC model mice possibly by inhibiting Toll-like receptor 4 (TLR4)/NF-κB signalling and the expression of colon cancer markers, such as carcinoembryonic antigen, cytokeratin 8, CK18 and p53, in CAC model mice. In addition, lentinan restored the intestinal bacterial microbiotal community structure in IBD model mice. Thus, it shows therapeutic potential in IBD and CAC model mice possibly by inhibiting TLR4/NF-κB signalling-mediated inflammatory responses and disruption of the intestinal microbiotal structure.

Oleanolic Acid Inhibits Epithelial-Mesenchymal Transition of Hepatocellular Carcinoma by Promoting iNOS Dimerization.

Oleanolic acid exhibits extensive pharmacologic activities and takes significant antitumor effects. Its pharmacologic mechanism, however, still remained to be further clarified. In this study, we demonstrated that oleanolic acid attenuated the migration and invasion abilities, resulting in the suppression of the epithelial-mesenchymal transition (EMT) process in liver cancer cells, and inhibited the tumor growth of the peritoneal lymphocytes-bearing mice. We further proved that inducible nitric oxide synthase (iNOS) may be the potential target of oleanolic acid. We confirmed that oleanolic acid could promote the dimerization of iNOS, activating it, and subsequently increasing the production of nitric oxide. Further experiments indicated that oleanolic acid promoted the nitration of specific proteins and consequently suppressed their EMT-related biological functions. Furthermore, it has been confirmed that oleanolic acid enhanced the antitumor effects of regorafenib in liver cancer treatment. These results deepened our understanding of the pharmacologic mechanism of the antitumor effect oleanolic acid, and the importance of nitric oxide synthetase as a therapeutic target for liver cancer treatment.

Selenium-lentinan inhibits tumor progression by regulating epithelial-mesenchymal transition.

BACKGROUND: Selenium supplementation can be used to treat tumors. However, inorganic selenium is highly toxic, and natural organic selenium is extremely rare. Polysaccharides can improve drug bioavailability and targeting. Lentinan is a polysaccharide that has been approved as an anti-cancer drug in Japan and China. METHODS: Lentinan, an antitumor polysaccharide extracted from Lentinus edodes, was conjugated with seleninic acid to be transformed into ester (Se-lentinan) and utilized as drug carrier. The enhancement of the anti-tumor effects of Se-lentinan was evaluated by cell viability, cell cycle, migration, and transwell assays and animal xenograft models. The effects of Se-lentinan on the expression levels of epithelial-mesenchymal transition (EMT) markers were determined through immunofluorescence, Western blot, and immunohistochemistry analyses. RESULTS: Se-lentinan inhibited the invasiveness of B16-BL6 and HCT-8 cells by suppressing EMT. In vivo, Se-lentinan significantly inhibited tumor growth and metastasis of the transplanted melanoma and colon cancer cells and showed less toxicity than sodium selenite. Moreover, Se-lentinan reduced the accumulation of selenium in the liver and kidney tissues of mice and exhibited low organ toxicity. CONCLUSION: The antitumor activity of selenium was enhanced greatly, and its side effects were reduced with the use of lentinan as drug carrier.