Pharmacological effect and mechanism of orlistat in anti-tumor therapy: A review.

Research has demonstrated that obesity is an important risk factor for cancer progression. Orlistat is a lipase inhibitor with promising therapeutic effects on obesity. In addition to being regarded as a slimming drug, a growing number of studies in recent years have suggested that orlistat has anti-tumor activities, while the underlying mechanism is still not well elucidated. This paper reviewed recent pharmacological effects and mechanisms of orlistat against tumors and found that orlistat can target cancer cells through activation or suppression of multiple signaling pathways. It can induce tumor cells apoptosis or death, interfere with tumor cells' cycles controlling, suppress fatty acid synthase activity, increase ferroptosis, inhibit tumor angiogenesis, and improve tumor cells glycolytic. Thus, this review may shed new light on anti-tumor mechanism and drug repurposing of orlistat, and anti-tumor drug development.

Clustered Regularly Interspaced Short Palindromic Repeats and Clustered Regularly Interspaced Short Palindromic Repeats-Associated Protein 9 System: Factors Affecting Precision Gene Editing Efficiency and Optimization Strategies.

The clustered regularly interspaced short palindromic repeat (CRISPR)-CRISPR-associated (Cas) system is a powerful genomic DNA editing tool. The increased applications of gene editing tools, including the CRISPR-Cas system, have contributed to recent advances in biological fields, such as genetic disease therapy, disease-associated gene screening and detection, and cancer therapy. However, the major limiting factor for the wide application of gene editing tools is gene editing efficiency. This review summarizes the recent advances in factors affecting the gene editing efficiency of the CRISPR-Cas9 system and the CRISPR-Cas9 system optimization strategies. The homology-directed repair efficiency-related signal pathways and the form and delivery method of the CRISPR-Cas9 system are the major factors that influence the repair efficiency of gene editing tools. Based on these influencing factors, several strategies have been developed to improve the repair efficiency of gene editing tools. This review provides novel insights for improving the repair efficiency of the CRISPR-Cas9 gene editing system, which may enable the development and improvement of gene editing tools.

Increased expression of PD­L1 by the human papillomavirus 16 E7 oncoprotein inhibits anticancer immunity.

Cytotoxic T lymphocyte dysfunction is frequently associated with PD­L1/PD­1 pathway activation, and is a principal obstacle in cancer therapy. In the present study, the mechanisms underlying the human papillomavirus (HPV)­induced evasion of cervical cancer cells to the host immune system via the programmed death ligand  1/programmed death 1 (PD­L1/PD­1) signaling pathway was investigated. A significant increase in the expression of the HPV16E7 viral protein and PD­L1 in cervical tissues was observed when compared with normal cervical tissues. In addition, a positive correlation between HPV16E7 and PD­L1 expression was observed by immunohistochemical staining and reverse transcription­polymerase chain reaction. Overexpressing HPV16E7 oncoprotein in the epithelial carcinoma of PC3 cells increased the expression level of the PD­L1 protein and inhibited peripheral blood mononuclear cell (PBMC) proliferation and cytotoxic T lymphocyte (CTL) activity. Upon knockdown of HPV16E7 in HPV16­associated CaSki cervical cancer cells with a relevant siRNA, a reduction in PD­L1 protein expression was observed, as well as a significant increase in PBMC proliferation and CTL activity. A recombinant plasmid, MSCVPIG­soluble PD­1, was constructed and transfected into the CaSki cell line, and was co­cultured with PBMCs. PBMC proliferation and CTL activity were observed to increase significantly. In conclusion, the results presented in the current study suggest that overexpression of PD­L1, induced by HPV16E7, may be responsible for lymphocyte dysfunction. In addition, soluble PD­1 may restore the function of tumor­infiltrating lymphocytes by inhibiting the PD­L1/PD­1 signaling pathway. These results may provide a novel insight for immunotherapeutic approaches in the treatment of cervical cancer.

Increased expression of PD-L1 by the human papillomavirus 16 E7 oncoprotein inhibits anticancer immunity.

Cytotoxic T lymphocyte dysfunction is frequently associated with PD­L1/PD­1 pathway activation, and is a principal obstacle in cancer therapy. In the present study, the mechanisms underlying the human papillomavirus (HPV)­induced evasion of cervical cancer cells to the host immune system via the programmed death ligand  1/programmed death 1 (PD­L1/PD­1) signaling pathway was investigated. A significant increase in the expression of the HPV16E7 viral protein and PD­L1 in cervical tissues was observed when compared with normal cervical tissues. In addition, a positive correlation between HPV16E7 and PD­L1 expression was observed by immunohistochemical staining and reverse transcription­polymerase chain reaction. Overexpressing HPV16E7 oncoprotein in the epithelial carcinoma of PC3 cells increased the expression level of the PD­L1 protein and inhibited peripheral blood mononuclear cell (PBMC) proliferation and cytotoxic T lymphocyte (CTL) activity. Upon knockdown of HPV16E7 in HPV16­associated CaSki cervical cancer cells with a relevant siRNA, a reduction in PD­L1 protein expression was observed, as well as a significant increase in PBMC proliferation and CTL activity. A recombinant plasmid, MSCVPIG­soluble PD­1, was constructed and transfected into the CaSki cell line, and was co­cultured with PBMCs. PBMC proliferation and CTL activity were observed to increase significantly. In conclusion, the results presented in the current study suggest that overexpression of PD­L1, induced by HPV16E7, may be responsible for lymphocyte dysfunction. In addition, soluble PD­1 may restore the function of tumor­infiltrating lymphocytes by inhibiting the PD­L1/PD­1 signaling pathway. These results may provide a novel insight for immunotherapeutic approaches in the treatment of cervical cancer.

Modification of sPD1 with CRT induces potent anti-tumor immune responses in vitro and in vivo.

As a key factor for tumor occurrence and development, tumor cells escape immune surveillance and inhibit the body immune killer effect through negative signaling pathways. In this research, we designed and expressed the fusion protein CRT-sPD1 to block PD1/PDL1 negative signal pathway, indirectly bind CRT to the tumor cell surface and to increase the cell immunogenicity activity. Results from western blotting, flow cytometry (FCM) and ELISA showed that the cell lines that stably express CRT, PD1 and CRT-sPD1 protein were obtained and the transfected cellular supernatant contained PD1 and CRT-sPD1 could bind to PDL1 on the surface of EL4 cells. Vitro experiments indicated the secreted mCRT-sPD1 protein could bind to PDL1 and enhance lymphocyte proliferation and CTL activity. We also found that fusion protein CRT-sPD1 could activate and induce the immune system to kill the tumor cells, specifically inhibit the tumor growth and prolong the survival period in mouse tumor model. And all these suggested that CRT-sPD1 could be used as drug development and utilization of cancer immunotherapy.

MiRNA-194 Regulates Palmitic Acid-Induced Toll-Like Receptor 4 Inflammatory Responses in THP-1 Cells.

There is strong evidence to suggest that inflammatory responses link obesity and diseases, and the understanding of obesity-induced inflammatory mechanisms is central to the pathogenesis of diseases such asnonalcoholic fatty liver disease(NAFLD) and atherosclerosis that are modified by obesity. Based on this, anti-inflammatory treatments become a potential therapies for obesity-related diseases like NAFLD.A critical role of toll-like receptor (TLR) and its downstream molecules such as tumor necrosis factor receptor-associated factor 6(TRAF6) has been documented in inflammatory response induced by fatty acid. TLR pathway regulation provides a new insight to controlling the inflammatory response induced by fatty acid. Taken together, our study was aimed to understand the mechanism of fatty acid-mediated inflammation and look for an effective target which can prevent the inflammatory response induced by obesity. In this study, we used the saturated fatty acid palmitic acid (PA) to activate TLR4 signal pathway in human monocyte cells THP-1 that established an intracellular inflammatory model. Followed with activated TLR4, downstream molecular TRAF6 was upregulated and ultimately induced proinflammatory cytokine production. Based on this model, we also found that PA downregulated miR-194 expression with TLR4 activation. Moreover, our results showed that key signal molecular TRAF6 is a target of miR-194, overexpression of miR-194 directly decreased TRAF6 expression and attenuated the release of proinflammatory cytokine TNF-α in PA-activated monocyte THP-1. We conclude that miR-194 negatively regulates the TLR4 signal pathway which is activated by PA through directly negative TRAF6 expression.

Evaluation of Annexin A2 as a novel diagnostic serum biomarker for lung cancer.

Annexin A2 (ANXA2) is a 36 kDa protein which orchestrates multiple biologic processes and clinical associations, especially in cancer progression. It is important to establish a specific and sensitive ANXA2 enzyme-linked immunosorbent assay (ELISA) for the study of ANXA2 functions and its clinical application. Therefore, we prepared a polyclonal antibody (PAb) in rabbits and a monoclonal antibody (MAb) in mices immunized with a recombinant ANXA2 protein. Based on our self-made MAb and PAb, highly specific and sensitive ELISA was developed. The detection limitation of ANXA2 was 10 ng/mL and the linear dynamic range was between 10 and 500 ng/mL. Using the established ELISA, we detected ANXA2 protein in human serum. It was found that soluble ANXA2 concentration in serum samples from 42 lung cancer patients was significantly higher than that from 43 healthy individuals (p< 0.01). Our data provides a new approach for detecting soluble ANXA2, especially in large ongoing and future clinical studies.