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Chimeric antigen receptor-modified T (CAR-T) are genetically engineered cells to express tumor-specific antigens revolutionizing the treatment of hematologic malignancies. The hostile tumor microenvironment (TME) remains a challenge for CAR-T cell therapy in solid tumors. As a solution, combinational therapy with immune checkpoint inhibitors (ICIs) is shown to improve the safety and efficacy of CAR-T cell therapy. To avoid side effects related to the application of ICIs in combinational therapy, engineering CARs to express tumor-specific antigens may help improvement of clinical outcomes. Those CARs expressing single chain variable fragments (scFvs) or nanobodies against immune checkpoint stimulatory or inhibitory molecules, such as the programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1) signaling axis are being extensively studied in various clinical trials. In this review, we discuss the significance of anti-PD-(L)1 scFv-expressing CAR-T cells in the treatment of human cancers, describing current challenges and potential strategies to overcome such predicaments in the area of cancer immunotherapy. [Display omitted] • CAR-T can be a strategy for revolutionizing ICI efficacy. • Anti-PD-(L)1-expressing CAR-T shows equal or better efficacy vs. separate combinational therapy. • Anti-PD-(L)1-expressing CAR-T minimizes toxicities related to systemic ICI application. [ABSTRACT FROM AUTHOR]

Radio- and chemotherapy are the most common cancer treatment modalities. They cause acute and late side effects on normal tissues, which is a burden for delivery of a high dose of radiation or drugs on tumor cells. In addition, tumor cells achieve adaptive responses to subsequent doses of radiation and chemotherapy, leading to tumor resistance and accelerated repopulation. Resistance to radiotherapy and chemotherapy can occur following adaptive responses, which itself is due to the release of large numbers of inter- and intracellular mediators by immune cells as well as other tumor microenvironment (TME) cells. Melatonin is a potent natural antioxidant and anti-inflammatory agent that protects against toxic side effects of radiation and chemotherapy. Furthermore, in some cancer cells, melatonin aids sensitizing cancer cells to therapy. Apoptosis is one of the main mechanisms of cell death following exposure to radiation and chemotherapy. Evidences have shown a direct relation between apoptosis induction in tumor cells with increased tumor delay regression and survival. Melatonin through modulation of several apoptosis mediators such as mitochondria, Bax, Bcl-2, endogenous ROS, and apoptosis receptors facilitate apoptosis. The current review aims to explain mechanisms of apoptosis induction following exposure to radiation and chemotherapy drugs. We also reviewed the modulatory effect of melatonin on apoptosis signaling pathways. Unlabelled Image [ABSTRACT FROM AUTHOR]

Myeloid-derived suppressor cells (MDSCs) are heterogeneous and poorly mature cells of innate immunity that their population is increased substantially in cancer patients. MDSCs represent three subsets including CD14+ monocytic (M), CD15+ granulocytic (G) and Lin− early precursor (e) cells. MDSCs release a number of factors that direct several tumorigenic-related events including immune evasion, angiogenesis and metastasis. Assessment of MDSCs can provide valuable information from cancer immunity state, and it can be an indicator of tumor prognosis. The cells can be targeted in combination with current immunotherapeutic schedules, and the outcomes were promising. The focus of this review is to provide an overview of MDSCs, their involvement in tumor-related immunosuppression, and their impact on cancer immunotherapy. Then, strategies are proposed to boost the power of immune system against MDSCs. [Display omitted] • M-MDSCs are CD14+, whereas G-MDSCs are CD15+. • Pre-treatment evaluation of MDSCs is of prognostic and therapeutic value. • MDSC recruitment into the tumor area is potentiated by chronic inflammation and hypoxia. • The dose of chemotherapy influences the fraction of circulatory MDSCs. • MDSC-targeting agents can be used for enhancing the efficacy of vaccination therapy. [ABSTRACT FROM AUTHOR]

Chemotherapy is an effective therapeutic modality which is commonly used for battling various cancers. However, several side effects induced by chemotherapeutic drugs would limit their clinical use. The present systematic review aims to evaluate the role of curcumin/curcuminoids co-administration during gastric cancer chemotherapy. This systematic review was done according to PRISMA guidelines and a full systematic search in the electronic databases up to May 2020 using search terms in the titles and abstracts for the identification of relevant literature. 279 articles were found in electronic databases and 175 articles screened by title and abstract. Finally, 13 articles were included in this systematic review according to our inclusion and exclusion criteria. The findings indicated that gastric cancer chemotherapy induces cytotoxicity effects in various ways including a decrease of cell viability, colony formation, metastasis, tumor growth, and weight, as well as elevation of apoptosis pathway, oxidative stress pathway compared to the control group. Co-administration of curcumin/curcuminoids with chemotherapy synergistically increased the effects of anti-cancer chemotherapy compared to the group solo treated with chemotherapeutic agents. Also, in chemoresistance gastric cancer cells, co-administration of curcumin reduced chemoresistance mainly through the reduction of NF-κB activation and elevation of apoptosis. According to the findings, the use of curcumin/curcuminoids during gastric cancer chemotherapy has chemosensitizing effects, and also it can reduce chemoresistance in gastric cancer. Unlabelled Image [ABSTRACT FROM AUTHOR]