Reversal of multidrug resistance in renal cell carcinoma by short hairpin RNA targeting MDR1 gene / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Over-expression of P-glycoprotein (P-gp), encoded by the MDR1 gene, confers multidrug resistance (MDR) in renal cell carcinoma (RCC) and is a major reason for unsuccessful chemotherapy. This study aimed to determine the effct of RNA interference (RNAi) on the reversal of MDR in human RCC.</p><p><b>METHODS</b>We designed and selected one short hairpin RNA (shRNA) targeting MDR1 gene, which is stably expressed from integrated plasmid and transfected by lentivirus fluid in human RCC A498 cell.</p><p><b>RESULTS</b>The MDR1-targeted RNAi resulted in decreased MDR1 gene mRNA level (P < 0.001), almost abolished P-gp expression and reversed MDR to different chemotherapy drugs in the RCC A498 cell line.</p><p><b>CONCLUSION</b>MDR could be reversed by RNAi in human RCC A498 cell line, which may be used for clinical application in future.</p>

Histone deacetylase inhibitor MS-275 treatment alters immune molecule content and categories in hepatocarcinoma exosomes / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the effects of the histone deacetylase inhibitor, MS-275, on the immune molecule content and categories in hepatocarcinoma exosomes.</p><p><b>METHODS</b>Exosomes were isolated from the human hepatocarcinoma cell lines, HepG2 and Hep3b, and purified by a combination technique of ultrafiltration centrifugation and sucrose gradient ultracentrifugation. The expressions of heat shock protein (HSP)70, human leukocyte antigen (HLA)-I, HLA-DR, cluster of differentiation (CD) 80 and NY-ESO-1 on exosomes were analyzed with immunoelectron microscopy and Western blotting before and after MS-275 treatment. Intergroup differences were statistically analyzed by the Student's paired t-test.</p><p><b>RESULTS</b>MS-275 treatment of both HepG2 and Hep3b cell types significantly increased the numbers of exosomes, their total protein content, and expression of HSP70, HLA-I and CD80 (per 100 exosomes), as compared to non-treated cells (all, P less than 0.01). MS-275 was also found to induce de novo expression of HLA-DR, but had no significant effect on NY-ESO-1 expression (P more than 0.05). The findings from immunoelectron microscopy confirmed those from Western blotting.</p><p><b>CONCLUSION</b>The histone deacetylase inhibitor, MS-275, can significantly alter the immune molecule content and categories in exosomes of hepatocarcinoma cells. The differential expression profile may reflect an anti-cancer immune response and represent molecular targets for novel anti-hepatoma therapeutic or preventative strategies.</p>

Up-regulation of visfatin expression in subjects with hyperthyroidism and hypothyroidism is partially relevant to a nonlinear regulation mechanism between visfatin and tri-iodothyronine with various concentrations / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Visfatin, a visceral fat-derived adipocytokine, plays a significant physiological function in lipid metabolism. However, the precise function of visfatin and its regulation by thyroid hormones are still unknown. This study observed the plasma visfatin concentrations in subjects with hyperthyroidism and hypothyroidism in vivo, and investigated the possible regulation mechanism between visfatin and tri-iodothyronine (T3) in vitro as a further interpretation.</p><p><b>METHODS</b>The experiment in vivo included clinical subjects (57 patients with thyroid dysfunction and 29 euthyroid healthy volunteers) and an animal model (24 Wistar rats). All subjects were divided into hyperthyroidism, hypothyroidism and euthyroidism groups, with plasma thyroid hormones, thyrotropin, visfatin and triglyceride concentrations determined. Visfatin mRNA expression in visceral fat and liver of rats was detected by quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR). The experiment in vitro studied 3T3-L1 cells and visfatin mRNA expression under nine different T3 concentrations (0, 0.1, 0.25, 0.5, 1, 5, 10, 20, 100 nmol/L) using quantitative real-time RT-PCR.</p><p><b>RESULTS</b>Clinical subjects and animal models showed elevated plasma visfatin concentrations in the hyperthyroidism group (20.466 ng/ml (15.263, 26.795 ng/ml) and (1209.164±165.292) ng/L) and hypothyroidism group (12.457 ng/ml (11.115, 15.454 ng/ml) and (1205.425±109.200) ng/L) compared to euthyroidism group (6.891 ng/ml (5.888, 8.803 ng/ml) and (926.650±54.002) ng/L, P<0.001). For animal models, visfatin mRNA expression in visceral fat in the hyperthyroidism and hypothyroidism groups increased about 3.33-fold and 1.98-fold compared to the euthyroidism group (P<0.001), which was positively correlated with plasma visfatin concentrations (r=0.713, P<0.001). However, no significant group difference (P>0.05) and correlation (r=0.121, P=0.572) was found in the liver. T3 induced a remarkable increase of visfatin mRNA expression in 3T3-L1 cells at low concentrations (0-0.5 nmol/L T3) followed by a sharp decrease at higher concentrations (0.5-100 nmol/L T3), with an inflection point at 0.5 nmol/L T3.</p><p><b>CONCLUSION</b>Elevated circulating visfatin levels in subjects with hyperthyroidism and hypothyroidism are possibly due to an increase of visfatin mRNA expression in visceral fat, and a nonlinear regulation mechanism on visfatin mRNA expression under various T3 concentrations might be involved.</p>

Advanced dermatofibrosarcoma protuberans treated with imatinib mesylate / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To evaluate the efficacy, side effects and toxicity of imatinib mesylate in the treatment of patients with locally advanced and/or metastatic dermatofibrosarcoma protuberans (DFSP).</p><p><b>METHODS</b>Twenty-four cases of advanced DFSP diagnosed by pathology and treated in our hospital from Nov. 2004 to Oct. 2009 were included in this study. The patients were treated with imatinib mesylate (dosage: 400 mg, po, qd) and carefully observed for treatment efficacy, side effects and survival time. There were 2 patients taking the drug as second line therapy, and other 22 patients as third or more than third line therapy.</p><p><b>RESULTS</b>The 24 patients were evaluable for the efficacy. There were 8 patients (33.3%) with CR, 10 pts (41.7%) PR, 2 patients (8.3%) SD, and 4 patients (16.7%) PD. The disease control rate (DCR = CR+PR+SD) was 83.3%. The median response time in 18 cases with CR and PR was 5.6 months. The median survival time in 20 cases with disease control was 30 months, however, that in nonresponse (PD) cases was only 10 months. Side reactions related to imatinib mesylate included nausea and vomiting (20.8%), neutropenia (12.5%), and edema (8.3%).</p><p><b>CONCLUSIONS</b>Our results are consistent with previous reports in the literature. Imatinib is a safe and effective moleucular target drug used for Chinese. Only mild adverse reactions occur in the treated patients. It is worth using imatinib in the treatment of advanced DFSP patients.</p>

Recent research advances on function of CD4+T lymphocytes / 中国实验血液学杂志

Cellular immunity is an important component of human immune system and plays a crucial role in the fight against tumor cell or invasive pathogens. Researches on cell-based immunotherapy have long been focused on eliciting tumor-specific CD8+ cytotoxic T lymphocytes (CTL) because of their potent killing activity and their ability to reject transplanted organs. However, the resulting treatments have been surprisingly poor at inducing complete tumor rejection, in both the experimental models and clinical trials. The CD4+ T cells has been studied mainly for their role as helpers for CD8+ CTL, even suggesting that the tumor-specific CD4 T regulatory cells could act as suppressors of antitumor responses. Recent studies indicated that CD4+T cells are not a pure cell lineage with single function, but a cell population with complex functions. Moreover CD4+ T cells may not only be helper cells, but also act as potent effector cells or partners with NK cells that can clear a wide variety of tumors. In a word, the antitumor potential of effector CD4+ T cells might have been underestimated. In this article, the classification and differentiation of CD4+ T cells, the function and secreted cytokines of CD4+ T cells, the CD4+ T cells and tumor immune, the tumor-immuno regulatory effects of CD4+ T cells, and clinical researches of CD4+ T cells are reviewed.

Effects of 5-aza-2'-deoxycytidine on the amount of exosomes and secreted immuno-associated proteins by hepatoma cells / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the effects of 5-Aza-deoxycytidine (5-Aza-CdR) on the amount of exosomes and immuno-associated proteins produced in hepatoma HepG2 and Hep3B cells.</p><p><b>METHODS</b>Exosomes derived from HepG2 and Hep3B cells with or without treatment by 5-Aza-CdR were isolated and purified by combination of ultrafiltration centrifugation and sucrose gradient ultracentrifugation. The number of exosomes was counted under the electron microscope. The concentration of proteins in exosomes was detected by BCA. The expression of HSP70, HLA-I and NY-ESO-1 proteins in exosomes was assayed by Western blot and immuno-electron microscopy. The mRNA expression of p53 gene was observed by reverse transcription-polymerase chain reaction (RT-PCR).</p><p><b>RESULTS</b>The mRNA expression of p53 gene was increased in both hepatoma cell lines after treatment with 5-Aza-CdR. The number of exosomes and the concentration of total proteins in exosomes were significantly increased after treatment by 5-Aza-CdR (P < 0.05). The immuno-electron microscopy and Western blotting showed that after treatment with 5-Aza-CdR, the contents of HSP70, HLA-I and NY-ESO-1 proteins were increased in exosomes in both HepG2 and Hep3B hepatoma cells.</p><p><b>CONCLUSION</b>5-Aza-CdR, an inhibitor of DNA methyltransferase, can increase the amount of exosomes and exosome-containning immuno-associated proteins secreted by hepatoma cells. It may be contributed by up-regulation of p53 gene and demethylation mechanism of 5-Aza-CdR.</p>

Analysis of methylation and loss of heterozygosity of RUNX3 gene in hepatocellular carcinoma and its clinical significance / 中华肝脏病杂志

<p><b>OBJECTIVE</b>In order to elucidate role of RUNX3 gene in hepatocarcinogenesis, we detected genetic and epigenetic alteration of RUNX3 gene in hepatocellular carcinoma (HCC).</p><p><b>METHODS</b>PCR-SSCP, analysis of loss of heterozygosity (LOH), sequencing and methylation-specific PCR (MSP) were used to detect mutation, LOH and DNA methylation of RUNX3 gene in 90 HCCs.</p><p><b>RESULTS</b>No mutation was found, but three single-nucleotide polymorphisms (SNP) were found and distributed over exon1 and exon4. 30.6% (11/36) of cases showed LOH; 54.4% (49/90) of cases was in hypermethylation. There is a significant correlation between LOH and major portal vein invasive or micro vessel invasion or intrahepatic metastasis.</p><p><b>CONCLUSION</b>High frequent hypermethylation and LOH of RUNX3 gene were found in HCC. Aberrant RUNX3 gene may play an important role in the development of HCC.</p>