[Effect of PPAR-γ agonist pioglitazone on the prolifeiration of malignant nesothelionma cells induced by HMGB1].

Objective: To investigate the effect and mechanism of PPAR-γ agonist Pioglitazone (PGZ) on the proliferation of malignant mesothelioma (MM) cells. Methods: In December 2019, MM cell lines MSTO-211H and NCI-H2452 were incubated with different final concentrations of PGZ (0, 10, 50, 100, 150, and 200 µmol/L) for different periods of time (24 h, 48 h, and 72 h) , and then the cell proliferation level was detected by CCK8 assay. After given various final concentration of PGZ (0, 10, 50, 100, 150, 200 µmol/L) the for 72 hours, the changes of number and morphology of MM cells were observed under an inverted microscope. The expressions of PPAR-γ and HMGB1 mRNA were determined by real-time fluorescence quantitative reverse transcription-polymerase chain reaction (qRT-PCR) after treatment of MM cells with PGZ of 0, 10, 50, 100 µmol/L for 72 h. The MM cells were treated with PGZ at concentration of 0, 100 µmol/L for 72 h, and the protein expressions of HMGB1 were examined using Western blotting and immunofluorescence; the protein expressions of Ki67 were assessed by immunohistochemistry. Results: The cell viability rate of MM cells was decreased after treated with PGZ (P<0.05) . Cell number in PGZ-treated group was significantly less than that in control group and morphology changes were observed under light microscope. QRT-PCR results revealed significantly increased PPAR-γ mRNA expression in the PGZ-treated group compared to the control group (P<0.05) . There was a significant decrease in the mRNA expression level of HMGB1 in the PGZ-treated group (100 µmol/L) as compared to the control group in MSTO-211H (P<0.05) ; however, the expression level of HMGB1 in NCI-H2452 was an increase or no significant differences (P>0.05) . Western blotting and immunofluorescence results showed that the protein expression of HMGB1 was reduced in the PGZ-treated group compared with the control group in MSTO-211H (P<0.05) , but the protein expression of that in NCI-H2452 was no significant differences (P>0.05) . Immunohistochemistry results showed increased expression of proliferation marker Ki-67. Conclusion: Pioglitazone suppresses the proliferation of MM cells through inhibition of HMGB1 by the activation of PPAR-γ.

[Advances in the cytotoxic mechanism of nanomaterials graphene oxide].

Graphene oxide is a novel two-dimensional carbon nanomaterial, but it has potential risks for the health of occupationally exposed workers. This article briefly reviews the research progress on the cytotoxic mechanism of graphene oxide and its derivatives in terms of oxidative stress, physical damage and dysfunction of enzyme activity. This review also discusses effective measures for the mitigation of cytotoxicity in order to provide helpful evidence for occupational health risk and biological safety assessment of graphene nanomaterials in China.

[The impact of CD8 and CTLA-4 expression on histopathological character and survival in mesothelioma].

Objective: To investigate the survival and death risk factors of mesothelioma cases stratified by the expression levels of CD8 and cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) , providing new clue to evaluate disease progression and clinical outcome. Methods: This was a retrospective case report, which included 47 clinically and pathologically confirmed mesothelioma cases on November 2016. Their clinical and pathological information, asbestos exposure history and survival data were collected. Infiltrated lymphocyte, 5-methylcytosine (5-mC) , CTLA-4, CD8 and Ki-67 antigen were detected using hematoxylin-eosin staining and immunohistochemistry. Survival time and death risk factors of mesothelioma patients with different CD8 and CTLA-4 protein expression characteristics were analyzed. And analyze the influence of Ki-67 expression on the survival of patients with different CD8 and CTLA-4 protein and gene expression characteristics. Results: Among the 47 cases, 63.8% (30/47) had low/medium level of infiltrated lymphocyte. The immunohistochemistry scores of CTLA-4, CD8, 5-mC and Ki-67 were 92.97 (54.95, 120.65) , 72.41 (36.62, 89.82) , 11.09 (3.40, 52.89) and 5.88 (2.41, 11.48) , respectively. Patients with CD8(high) CTLA-4(high) had higher 5-mC level than those with CD8(high) CTLA-4(low) (P<0.01) . The median survival time of 27 cases was 0.83±0.29 year. The median survival times of those with CD8(high) CTLA-4(high) and CD8(high) CTLA-4(low) were 0.58±0.51 year and 0.83±0.30 year, respectively (P=0.521) . The immunohistochemistry score of Ki-67 ≥5.88 was an independent death risk factor for patients with CD8(high) CTLA-4(low) (HR=8.40, P=0.01) . Under different CD8 and CTLA-4 protein expression characteristics, in the patients with CD8(high) CTLA-4(low), the median survival times of those with high and low Ki-67 expression were 0.57±0.11 years and 2.31±0.46 years, respectively (P<0.01) . Under different CD8 and CTLA-4 mRNA expression characteristics, in the patients with CD8(high) CTLA-4(low), the median survival times of those with high and low Ki-67 mRNA expression were 1.20±0.36 years and 3.38±0.43 years, respectively (P=0.018) . Conclusion: Mesothelioma case with high CD8 but low CTLA-4 content might coexist DNA hypomethylation. In the presence of high Ki-67 expression, their survival time appears to be shortened with increased death risk.

[Changes of microRNAs profiling in mesothelial cells exposed to multi-walled carbon nanotubes].

Objective: To explore the cytotoxicities of MWCNT to the mesothelial cells and screen the changes of microRNA profile after exposure to MWCNT. Methods: A LDH method was used to test the cytotoxicities of MWCNT to MeT-5A cell lines. And then the differentially expressed miRNAs between mesothelioma cells and normal mesothelial cells were selected from previous work of research group. Among the significant expression changed miRNAs, 5 were verified by RT-qPCR in mesothelioma cells. The same five ones were further tested in MeT-5A cells exposed to 10 µg/cm2 MWCNT for 8, 24, 48, 72 h by RT-qPCR. Target genes of 5 miRNAs were predicted using Targetscan and miRanda softwares. David6.7 was used to perform GO enrichment and KEGG pathway analysis of target genes. All the data were analyzed by one-way ANOVA and Dunnett-T test in SPSS17.0. Results: After 24 h exposure to MWCNT, cell proliferation was significantly suppressed at more than 20 µg/cm2 concentration. Among the differentially expressed miRNAs, 5 were chosen to further vestified, namely hsa-miR-155 (up-regulated) , hsa-miR-30 d-5p, hsa-miR-34c-5p, hsa-miR-28-5p and hsa-miR-324-5p (down-regulated) , which were consistent with the miRNA array results. The 5 miRNAs also had the same expression changes in MeT-5A cells after exposure to 10 µg/cm2 MWCNT for different time periods. The potential target genes of the 5 miRNAs may be AKAP13, CCND3, Twist and E-Cadherin, which mainly involved in TGF-ß signal pathway, small cell lung cancer, etc. Conclusion: MWCNT could induce to MeT-5A cells, and also cause miRNA expression changes. The differential changed miRNAs may involve in cancer related signal pathways.