Radiofrequency radiation reshapes tumor immune microenvironment into antitumor phenotype in pulmonary metastatic melanoma by inducing active transformation of tumor-infiltrating CD8+ T and NK cells.

Immunosuppression by the tumor microenvironment is a pivotal factor contributing to tumor progression and immunotherapy resistance. Priming the tumor immune microenvironment (TIME) has emerged as a promising strategy for improving the efficacy of cancer immunotherapy. In this study we investigated the effects of noninvasive radiofrequency radiation (RFR) exposure on tumor progression and TIME phenotype, as well as the antitumor potential of PD-1 blockage in a model of pulmonary metastatic melanoma (PMM). Mouse model of PMM was established by tail vein injection of B16F10 cells. From day 3 after injection, the mice were exposed to RFR at an average specific absorption rate of 9.7 W/kg for 1 h per day for 14 days. After RFR exposure, lung tissues were harvested and RNAs were extracted for transcriptome sequencing; PMM-infiltrating immune cells were isolated for single-cell RNA-seq analysis. We showed that RFR exposure significantly impeded PMM progression accompanied by remodeled TIME of PMM via altering the proportion and transcription profile of tumor-infiltrating immune cells. RFR exposure increased the activation and cytotoxicity signatures of tumor-infiltrating CD8+ T cells, particularly in the early activation subset with upregulated genes associated with T cell cytotoxicity. The PD-1 checkpoint pathway was upregulated by RFR exposure in CD8+ T cells. RFR exposure also augmented NK cell subsets with increased cytotoxic characteristics in PMM. RFR exposure enhanced the effector function of tumor-infiltrating CD8+ T cells and NK cells, evidenced by increased expression of cytotoxic molecules. RFR-induced inhibition of PMM growth was mediated by RFR-activated CD8+ T cells and NK cells. We conclude that noninvasive RFR exposure induces antitumor remodeling of the TIME, leading to inhibition of tumor progression, which provides a promising novel strategy for TIME priming and potential combination with cancer immunotherapy.

Cadmium Exposure is Associated with the Prevalence of Dyslipidemia.

BACKGROUND: Cadmium is a widespread environmental and occupational pollutant that accumulates in human body with a biological half-life exceeding 10 years. Cadmium exposure has been demonstrated to increase rates of cardiovascular diseases. Whether occupational cadmium exposure is associated with the increase in the prevalence of dyslipidemia and hence contributes to the risk of cardiovascular diseases is still equivocal. To test the hypothesis that exposure to cadmium is related to the prevalence of dyslipidemia, we examined the associations between blood cadmium concentration and the prevalence of dyslipidemia in workers occupationally exposed to cadmium in China. METHODS: A cross-sectional survey on demographic data, blood cadmium level and lipid profile in cadmium exposed workers from seven cadmium smelting factories in central and southwestern China was conducted. We measured blood cadmium concentration and lipid components of 1489 cadmium exposed workers. The prevalence of dyslipidemia was compared across blood cadmium quartiles. Associations between the blood cadmium concentrations and the prevalence of dyslipidemia were assessed using confounder adjusted linear and logistic regressions. RESULTS: The blood cadmium concentration was 3.61±0.84µg/L ( mean ±SD). The prevalence of dyslipidemia in this occupational population was 66.3%. Mean blood cadmium concentration of workers with dyslipedemia was significantly higher than that of workers without dyslipidemia (p <0.01). The prevalence of dyslipidemia increased dose-dependently with elevations in blood cadmium concentrations (p for trend <0.001). Elevated levels of blood cadmium were associated with BMI, education attainment, income, smoking status and duration of exposure (all p <0.01). Furthermore, the profile of blood lipid was obviously changed in this occupational population. The prevalence of high TC, high TG, Low HDL-C and high LDL-C rose with increases in blood cadmium levels dose-dependently (p for trend <0.001). The odds ratios (95% confidence interval) for dyslipidemia across the increasing blood cadmium quartiles were 1.21(1.16-1.55), 1.56(1.11-1.87), 1.79(1.26-2.25) respectively (referencing to 1.00; p for trend <0.001), after multivariate adjustment for BMI, education attainment, income, lifestyle factors and duration of exposure, the association between blood cadmium concentrations and the prevalence of dyslipidemia remained unchanged (all p for trend <0.001). CONCLUSION: Elevated blood cadmium concentration is associated with prevalence of dyslipidemia. Cadmium exposure could alter lipid metabolism in humans. It is imperative to control cadmium exposure of occupational population in cadmium related industries and reduce adverse health effects.

NiO nanoparticles induce apoptosis through repressing SIRT1 in human bronchial epithelial cells.

With application of nano-sized nickel-containing particles (Nano-Ni) expanding, the health concerns about their adverse effects on the pulmonary system are increasing. However, the mechanisms for the pulmonary toxicity of these materials remain unclear. In the present study, we focused on the impacts of NiO nanoparticles (NiONPs) on sirtuin1 (SIRT1), a NAD-dependent deacetylase, and investigated whether SIRT1 was involved in NiONPs-induced apoptosis. Although the NiONPs tended to agglomerate in fluid medium, they still entered into the human bronchial epithelial cells (BEAS-2B) and released Ni(2+) inside the cells. NiONPs at doses of 5, 10, and 20µg/cm(2) inhibited the cell viability. NiONPs' produced cytotoxicity was demonstrated through an apoptotic process, indicated by increased numbers of Annexin V positive cells and caspase-3 activation. The expression of SIRT1 was markedly down-regulated by the NiONPs, accompanied by the hyperacetylation of p53 (tumor protein 53) and overexpression of Bax (Bcl-2-associated X protein). However, overexpression of SIRT1 through resveratrol treatment or transfection clearly attenuated the NiONPs-induced apoptosis and activation of p53 and Bax. Our results suggest that the repression of SIRT1 may underlie the NiONPs-induced apoptosis via p53 hyperacetylation and subsequent Bax activation. Because SIRT1 participates in multiple biologic processes by deacetylation of dozens of substrates, this knowledge of the impact of NiONPs on SIRT1 may lead to an improved understanding of the toxic mechanisms of Nano-Ni and provide a molecular target to antagonize Nano-Ni toxicity.

[Expression and roles of the epithelial mesenchymal transition markers E-cadherin and vimentin in hepatocellular carcinoma].

OBJECTIVE: To determine the differential protein expressions of epithelial mesenchymal transition (EMT) markers E-cadherin and vimentin in hepatocellular carcinorma (HCC) and to investigate their correlation to the molecular mechanisms of metastasis to explore their potential utility as prognostic indicators of HCC. METHODS: Tumor tissues and patient-matched adjacent non-tumor tissues were collected from individuals diagnosed with HCC. E-cadherin and vimentin protein expressions in the tissue specimens were quantified by western blot with densitometry of fluorescence emission and comparatively analyzed to determine the associations with molecular and clinical features. The expressions of E-cadherin and vimentin, as well as the other EMT-related protein Twist, were also detected in the tissue specimens by immunohistochemistry. Statistical analyses were carried out by paired-samples t-test, Mann-Whitney test, and Spearman rank correlation analysis. RESULTS: E-cadherin expression was significantly lower in tumor tissues (0.082 +/- 0.063 vs. adjacent non-tumor tissues: 0.226 +/- 0.215, t = -4.050, P less than 0.01), lower in patients with portal vein tumor thrombus (vs. non-thrombic HCC patients, P = 0.001), and correlated with TNM stage (III/IV > I/II, P = 0.003). Vimentin expression was significantly higher in tumor tissues (vs. adjacent non-tumor tissues, P = 0.002), negatively correlated with E-cadherin expression (t = -0.509, P = 0.004), and closely associated with some clinical parameters, such as portal vein tumor thrombus (P less than 0.01), TNM stage (P less than 0.01), and Milan criteria (P = 0.005). Immunohistochemistry showed that E-cadherin expression was very weak in tumors but very strong in the cell membranes of non-tumor tissues, and that vimentin and Twist expressions were strong in tumors but undetectable in non-tumor tissue. CONCLUSION: Expression levels of the EMT markers E-cadherin and vimentin in HCC are related to clinical parameters, including portal vein tumor thrombus and TNM stage, and may represent useful prognostic markers of metastasis.

Damage to mtDNA in liver injury of patients with extrahepatic cholestasis: the protective effects of mitochondrial transcription factor A.

Oxidative stress and mitochondrial dysfunction are involved in the pathogenesis of chronic liver cholestasis. Mitochondrial DNA (mtDNA) is highly susceptible to oxidative stress and mtDNA damage leads to mitochondrial dysfunction. This study aimed to investigate the mtDNA alterations that occurred during liver injury in patients with extrahepatic cholestasis. Along with an increase in malondialdehyde (MDA) levels and a decrease in ATP levels, extrahepatic cholestatic patients presented a significant increase in mitochondrial 8-hydroxydeoxyguanosine (8-OHdG) levels and decreases in mtDNA copy number, mtDNA transcript levels, and mtDNA nucleoid structure. In L02 cells, glycochenodeoxycholic acid (GCDCA) induced similar damage to the mtDNA and mitochondria. In line with the mtDNA alterations, the mRNA and protein levels of mitochondrial transcription factor A (TFAM) were significantly decreased both in cholestatic patients and in GCDCA-treated L02 cells. Moreover, overexpression of TFAM could efficiently attenuate the mtDNA damage induced by GCDCA in L02 cells. However, without its C-tail, ΔC-TFAM appeared less effective against the hepatotoxicity of GCDCA than the wild-type TFAM. Overall, our study demonstrates that mtDNA damage is involved in liver damage in extrahepatic cholestatic patients. The mtDNA damage is attributable to the loss of TFAM. TFAM has mtDNA-protective effects against the hepatotoxicity of bile acid during cholestasis.