Immune cells within the tumor microenvironment: Biological functions and roles in cancer immunotherapy.

The immune cells within the tumor microenvironment (TME) play important roles in tumorigenesis. It has been known that these tumor associated immune cells may possess tumor-antagonizing or tumor-promoting functions. Although the tumor-antagonizing immune cells within TME tend to target and kill the cancer cells in the early stage of tumorigenesis, the cancer cells seems to eventually escape from immune surveillance and even inhibit the cytotoxic function of tumor-antagonizing immune cells through a variety of mechanisms. The immune evasion capability, as a new hallmark of cancer, accidently provides opportunities for new strategies of cancer therapy, namely harnessing the immune cells to battle the cancer cells. Recently, the administrations of immune checkpoint modulators (represented by anti-CTLA4 and anti-PD antibodies) and adoptive immune cells (represented by CAR-T) have exhibited unexpected antitumor effect in multiple types of cancer, bringing a new era for cancer therapy. Here, we review the biological functions of immune cells within TME and their roles in cancer immunotherapy, and discuss the perspectives of the basic studies for improving the effectiveness of the clinical use.

Analysis of Plasmodium falciparum Na+/H+ exchanger (pfnhe1) polymorphisms among imported African malaria parasites isolated in Wuhan, Central China.

BACKGROUND: Quinine (QN) remains an effective drug for malaria treatment. However, quinine resistance (QNR) in Plasmodium falciparum has been reported in many malaria-endemic regions particularly in African countries. Genetic polymorphism of the P. falciparum Na+/H+ exchanger (pfnhe1) is considered to influence QN susceptibility. Here, ms4760 alleles of pfnhe1 were analysed from imported African P. falciparum parasites isolated from returning travellers in Wuhan, Central China. METHODS: A total of 204 dried-blood spots were collected during 2011-2016. The polymorphisms of the pfnhe1 gene were determined using nested PCR with DNA sequencing. RESULTS: Sequences were generated for 99.51% (203/204) of the PCR products and 68.63% (140/204) of the isolates were analysed successfully for the pfnhe1 ms4760 haplotypes. In total, 28 distinct ms4760 alleles containing 0 to 5 DNNND and 1 to 3 NHNDNHNNDDD repeats were identified. For the alleles, ms4760-1 (22.86%, 32/140), ms4760-3 (17.86%, 25/140), and ms4760-7 (10.71%, 15/140) were the most prevalent profiles. Furthermore, 5 undescribed ms4760 alleles were reported. CONCLUSIONS: The study offers an initial comprehensive analysis of pfnhe1 ms4760 polymorphisms from imported P. falciparum isolates in Wuhan. Pfnhe1 may constitute a good genetic marker to evaluate the prevalence of QNR in malaria-endemic and non-endemic regions.

Microcystin-LR in peripheral circulation worsens the prognosis partly through oxidative stress in patients with hepatocellular carcinoma.

Prognostic significance of serum microcystin in hepatocellular carcinoma has not been well investigated. The aim of the study was to reveal the relationship between serum microcystin-LR and prognosis in these patients. There were 650 early-stage hepatitis B-induced hepatocellular carcinoma patients, who were not affected by hepatitis C, cirrhosis, heavy drinking or excessive aflatoxin exposure. All of them underwent hepatectomy and were followed up for 5 years. Tumor relapse and overall death were recorded. Blood specimens were collected on admission and at the time of relapse. Serum levels of microcystin-LR and fluorescent oxidation products (FlOP_360, FlOP_320 and FlOP_400) were measured separately using enzyme-linked immunosorbent assay and fluorescence spectrometry. Multifactorial COX regression analysis suggested that serum microcystin-LR ≥ 0.97 ng/ml was associated with the increased risk of the tumor relapse (HR: 1.53, 95% CI: 1.35-1.77) and serum microcystin-LR ≥ 1.09 ng/ml was related to the higher risk of the overall death (HR: 1.58, 95% CI: 1.35-1.84) in the follow-up period. Furthermore, there was a linear relationship between serum level of microcystin-LR and serum levels of FlOP_360, FlOP_320 and FlOP_400 (P = 0.001, P = 0.023, P = 0.047). Serum levels of these fluorescent oxidation products were also higher in the patients with tumor relapse (P < 0.001, P < 0.001, P = 0.001) or overall death (P < 0.001, P = 0.001, P = 0.002) compared with the remaining patients. Serum microcystin-LR independently worsens the prognosis partly through promoting oxidative stress in patients with hepatocellular carcinoma.

Trillin Reduces Liver Chronic Inflammation and Fibrosis in Carbon Tetrachloride (CCl4) Induced Liver Injury in Mice.

UNLABELLED: Trillin is an active ingredient isolated from Dioscorea nipponica Makino. This study investigated the anti-inflammatory and anti-fibrosis effects of trillin on CCl4-induced hepatotoxicity in C57BL/6 mice. Chronic inflammation and fibrosis were induced by intraperitoneal administration of CCl4 0.5 µL/g of body weight twice a week for 6 weeks. Trillin (50 mg/kg, 100 mg/kg) was administered by gavage for 12 days before finishing the CCl4 induction. Aspartate amino-transferase (AST) and glutamic-pyruvic transaminase (ALT) in serum were determined by AST and ALT kits. Superoxidase dismutase (SOD) activity and malondialdehyde (MDA) levels in serum were assayed by SOD and MDA kits. Meanwhile, the levels of inflammatory mediators including tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1ß (IL-1ß) in serum were detected by enzyme-linked immunosorbent assay (ELISA) method. Pathological changes were observed by hematoxylin-eosin (HE) staining. The proteins of the NF-κB pathway and the TGF-ß/Smad pathway were measured by western blot. The trillin-treated group exhibited reduced AST, ALT, MDA, IL-6, TNF-α, and IL-1ß, and increased SOD. Histological analyses of the trillin-treated group exhibited reduced inflammatory process and prevented liver fibrosis. Western blot analyses of the trillin-treated group showed reduced NF-κB pathway and TGF-ß/Smad pathway. SIGNIFICANCE: Based on the results of the present study, trillin can be used as a potential anti-inflammatory drug for chronic hepatic inflammation.

Mechanism of action of gypenosides on type 2 diabetes and non-alcoholic fatty liver disease in rats.

AIM: To explore the mechanism of action of gypenosides (GPs) on type 2 diabetes mellitus and non-alcoholic fatty liver disease (T2DM-NAFLD) in rats. METHODS: Sixty rats were randomly divided into a healthy group, an untreated disease model group and GP-treatment groups. The study involved the evaluation of biochemical parameters, including serum aspartate transaminase (AST), alanine transferase (ALT), blood glucose (BG), triglycerides (TG) and total cholesterol (TC). Additionally, the protective effect of the treatments were confirmed histopathologically and the expression of TNF-α and NF-κB in the rat liver was analyzed using immunohistochemistry. The expression of proliferator-activated receptor gamma (PPARγ) and cytochrome P450 (CYP450) 1A1 mRNA was determined by quantitative RT-PCR. RESULTS: GP treatments at oral doses of 200, 400, and 800 mg/kg per day significantly decreased the levels of serum AST and ALT (P<0.05, P<0.01), especially at the dose of 800 mg/kg per day. To a similar extent, GP at 800 mg/kg per day reduced the levels of BG (4.19±0.47, P<0.01), TG (80.08±10.05, P<0.01), TC (134.38±16.39, P<0.01) and serum insulin (42.01±5.04, P<0.01). The expression of TNF-α and NF-κB measured by immunohistochemistry was significantly reduced by GPs in a dose-dependent manner, and the expression of PPARγ and CYP4501A1 mRNA, as measured using quantitative real-time PCR, were significantly down-regulated by GPs. Moreover, GPs decreased the infiltration of liver fats and reversed the histopathological changes in a dose-dependent manner. CONCLUSION: This study suggests that GPs have a protective effect against T2DM-NAFLD by down-regulating the expression of TNF-α and NF-κB proteins, and PPARγ and CYP4501A1 mRNAs.