UHRF1/DNMT1-MZF1 axis-modulated intragenic site-specific CpGI methylation confers divergent expression and opposing functions of PRSS3 isoforms in lung cancer

As confusion mounts over RNA isoforms involved in phenotypic plasticity, aberrant CpG methylation-mediated disruption of alternative splicing is increasingly recognized as a driver of intratumor heterogeneity (ITH). Protease serine 3 (PRSS3), possessing four splice variants (PRSS3-SVs; PRSS3-V1-V4), is an indispensable trypsin that shows paradoxical effects on cancer development. Here, we found that PRSS3 transcripts and their isoforms were divergently expressed in lung cancer, exhibiting opposing functions and clinical outcomes, namely, oncogenic PRSS3-V1 and PRSS3-V2 versus tumor-suppressive PRSS3-V3, by targeting different downstream genes. We identified an intragenic CpG island (iCpGI) in PRSS3. Hypermethylation of iCpGI was mediated by UHRF1/DNMT1 complex interference with the binding of myeloid zinc finger 1 (MZF1) to regulate PRSS3 transcription. The garlic-derived compound diallyl trisulfide cooperated with 5-aza-2'-deoxycytidine to exert antitumor effects in lung adenocarcinoma cells through site-specific iCpGI demethylation specifically allowing MZF1 to upregulate PRSS3-V3 expression. Epigenetic silencing of PRSS3-V3 via iCpGI methylation (iCpGIm) in BALF and tumor tissues was associated with early clinical progression in patients with lung cancer but not in those with squamous cell carcinoma or inflammatory disease. Thus, UHRF1/DNMT1-MZF1 axis-modulated site-specific iCpGIm regulates divergent expression of PRSS3-SVs, conferring nongenetic functional ITH, with implications for early detection of lung cancer and targeted therapies.

Killing effects of 5-Aza-CdR combined with EBNA1-DC vaccine-induced lymphocytes on nasopharyngeal carcinoma C666-1 cells / 中国肿瘤生物治疗杂志

@#[摘 要] 目的：探讨EB病毒核抗原1（EBNA1） mRNA修饰的DC（EBNA1-DC）诱导的淋巴细胞联合甲基化抑制剂5-Aza-CdR对鼻咽癌C666-1细胞的杀伤作用。方法：以构建的EBNA1-pCDNA3.1质粒为模板，体外转录获得EBNA1 mRNA，通过脂质体转染至健康人外周血来源DC，构建EBNA1-DC疫苗。流式细胞术检测转染后DC表型及5-Aza-CdR处理后的C666-1细胞凋亡情况。实时无标记动态细胞分析技术检测EBNA1-DC疫苗诱导的淋巴细胞联合5-Aza-CdR的特异性抗肿瘤活性。结果：转染EBNA1 mRNA后EBNA1-DC表面EBNA1阳性率为（59.3±5.85）%，HLA-DR的表达与未转染DC相比显著升高[（84.9±5.5）% vs （68.0±5.8）%，P=0.026]，CD80的表达也显著升高[（88.2±3.9）% vs （61.1±4.4）%，P=0.015]。低剂量5-Aza-CdR处理后的C666-1细胞凋亡情况与未处理的细胞相比无显著差异。经低浓度5-Aza-CdR预处理的C666-1细胞中IRF7基因表达与未处理的细胞相比显著升高（P=0.000 1）。与空载的DC相比，EBNA1-DC诱导的淋巴细胞对EBV阳性表达的C666-1细胞具有更强的特异性杀伤活性（P=0.049）；经低浓度5-Aza-CdR预处理的C666-1细胞对EBNA1-DC诱导的特异性免疫杀伤更敏感（P=0.019）。结论：5-Aza-CdR与EBNA1-DC疫苗联合可显著增强对C666-1细胞的特异性免疫杀伤，本研究为开拓以mRNA为基础的DC疫苗及其在临床综合治疗中的应用转化提供前期研究基础。

Effects of 5-aza-2'-deoxycytidine on proliferation of SPC-Al cells and expression of SFRPl and MGMT methylated proteins in lung cancer / 中国药理学通报

Aim To observe the effect of methylation inhibitors of 5-aza-2'-deoxycytidine (5-Aza-CdR) on SPC-Al - lung cancer cell proliferation, cell scratches and apoptosis, to explore the influence of secretion curl associated protein 1 (SFRPl) and 06-methylguanine-DNA-methyltransferase (MGMT) gene promoter region in which DNA methylation mRNA and protein expression and meaning. Methods The effects of 5-Aza-CdR at different concentrations on the proliferation of human lung cancer SPC-A 1 cells were determined by CCK-8 assay. The effect of 5-Aza-CdR on the migration ability of SPC-A 1 cells was determined by scratch assay. The apoptosis of lung cancer SPC-A 1 cells was detected by Hoechst 33258 staining after treatment with 5-Aza-CdR for 24 h. mRNA and protein expressions of SFRPl and MGMT in SPC-Al cells were detected by RT-PCR and Western blot. Results 5-Aza-CdR could reduce the proliferation of SPC-A 1 cells by concentration gradient,and IC50 was 21.2 jjimol • L

Research on the expression and regulation of ASPP2 and its methylationin human gastric carcinoma cell / 中华内分泌外科杂志

Objective To investigate the relationship between the expression of ASPP2 mRNA and the methylation of ASPP2 gene in gastric cancer cells,to observe the inhibitory effect of 5-Aza-CdR on the growth of gastric cancer cells,to observe the effect of demethylation on the expression of ASPP2 mRNA and the methylation of ASPP2 gene in gastric cancer cells,and to explore the molecular mechanism of gastric cancer.Methods Real-time PCR was used to detect the expression of ASPP2 mRNA in two gastric cancer cells and normal gastric epithelial cells.BSP was used to detect the methylation of ASPP2 gene in two gastric cancer cells and normal gastric epithelial cells.CCK-8 was used to detect the growth inhibition rate of gastric cancer cells treated with 5-Aza-CdR of different concentrations,then they were used to detect expression of ASPP2 mRNA and the methylation of ASPP2 gene in gastric cancer cells again after the demethylation.Results ① The expression of ASPP2 mRNA in MKN-45 cells was significantly lower than that in GES-1 cells(P＜0.01).The expression of ASPP2 mRNA in MGC-803 cells was significantly lower than that in GES-1 cells (P＜0.01).There was no significant difference in MGC-803 cells and MKN-45 cells(P＞0.05).② The methylation rate of ASPP2 in MKN-45 cells was significantly higher than that in GES-1 cells (P＜0.01).The methylation rate of ASPP2 in MGC-803 cells was not significantly different from that in GES-1 cells (P＞0.05).The methylation rate of ASPP2 in MKN-45 cells was significantly higher than that in MGC-803 cells (P＜0.01).③ At the same time,the growth inhibition rate of each 5-Aza-CdR concentration group increased as the drug concentration depended.4.The expression of ASPP2 mRNA in MKN-45 cells was significantly higher than that before treatment (P＜0.01),the expression of ASPP2 mRNA in MGC-803 cells was not significantly different from that before treatment(P＞0.05).The methylation rate of ASPP2 in MKN-45 cells was significantly lower than that before treatment (P＜0.01).The methylation rate of ASPP2 in MGC-803 cells was not significantly different from that before treatment (P＞0.05).Conclusion ① Abnormal hypermethylation of ASPP2 gene in MKN-45 cells may be a molecular mechanism of decreased ASPP2 mRNA expression.② 5-Aza-CdR can inhibit the growth of MKN-45 and MGC-803 cells,and it can enhance the expression of ASPP2 mRNA in MKN-45 cells.Reversal of methylation in the promoter region of ASPP2 gene is the possible mechanism.③ Abnormal hypermethylation of the promoter region of ASPP2 gene may lead to silencing of mRNA expression that may be associated with gastric cancer.

Development of precision medicine approaches based on inter-individual variability of BCRP/

Precision medicine is a rapidly-developing modality of medicine in human healthcare. Based on each patient׳s unique characteristics, more accurate dosages and drug selection can be made to achieve better therapeutic efficacy and less adverse reactions in precision medicine. A patient׳s individual parameters that affect drug transporter action can be used to develop a precision medicine guidance, due to the fact that therapeutic efficacy and adverse reactions of drugs can both be affected by expression and function of drug transporters on the cell membrane surface. The purpose of this review is to summarize unique characteristics of human breast cancer resistant protein (BCRP) and the genetic variability in the BCRP encoded gene in the development of precision medicine. Inter-individual variability of BCRP/ can impact choices and outcomes of drug treatment for several diseases, including cancer chemotherapy. Several factors have been implicated in expression and function of BCRP, including genetic, epigenetic, physiologic, pathologic, and environmental factors. Understanding the roles of these factors in controlling expression and function of BCRP is critical for the development of precision medicine based on BCRP-mediated drug transport.

Effects of DACT1 methylation status on invasion and metastasis of nasopharyngeal carcinoma

BACKGROUND: The purpose of the present study was to investigate the role of the methylation status of the DACT1 gene on the invasion and metastasis of nasopharyngeal carcinoma cells. METHODS: The levels of methylation and expression of the DACT1 gene in nasopharyngeal carcinoma tissues and CNE2 cells were determined by methylation-specific PCR and RT-PCR, respectively. CNE2 cells were treated with 5-aza-2-deoxycytidine, and the variation in the methylation status of the DACT1 gene was detected, as well as the influence of methylation on invasiveness of nasopharyngeal carcinoma cells. RESULTS: The DACT1 gene was hyper-methylated in 44 of 62 cases of nasopharyngeal carcinoma. The DACT1 gene was hyper-methylated in 32 of 38 cases of nasopharyngeal carcinoma with lymph node metastasis, and the DACT1 gene was hyper-methylated in 7 of 24 cases of nasopharyngeal carcinoma without lymph node metastasis. The DACT1 mRNA level was weakly expressed or not expressed in all nasopharyngeal carcinoma tissues with hyper-methylated DACT1 genes; however, the DACT1 mRNA level was highly expressed in nasopharyngeal carcinoma tissues with low expression of the methylated DACT1 gene. The DACT1 gene was hyper-methylated and not expressed in CNE2 cells that did not have 5-aza-2-deoxycytidine treatment. After 5-aza-2-deoxycytidine treatment, the DACT1 gene was demethylated and the expression of DACT1 was restored. Moreover, the invasion ability was inhibited in CNE2 cells treated with 5-aza-2-deoxycytidine. CONCLUSION: The expression of DACT1 was related to the methylation status. High expression of DACT1 may inhibit the invasion and metastasis of nasopharyngeal carcinoma cells.

Restoration of the lost B-cell phenotype in classical Hodgkin lymphoma cells by all trans-retinoic acid treatment / 中国比较医学杂志

Objective To investigate the induction of B-cell specific phenotype in classical Hodgkin lymphoma (cHL)upon all-trans retinoic acid(ATRA)incubation. Methods To construct B-cell specific promoter(CD19, CD79a,CD79b)driven reporter plasmid with NEO cassette to realize stable transfection and selection of cHL reporter cells. To verify the intact integration by amplification of the promoter and luciferase sequences,and to functionally validate the B-cell specific promoter by ABF1 interference and luciferase assay. Repoter cells were incubated with various doses of ATRA and luciferase activity was detected at 24,48 and 72 hours. Reporter cells were treated alone or in combination with 5-Aza and ATRA followed by luciferase assay. Endogenous B-cell specific genes(CD19, CD20, CD79a and CD79b) transcription and expression levels were detected by real-time PCR and immunoblot, respectively. The expression level of CD30 antigen on Hodgkin lymphoma cell membrane upon ATRA was assessed by flow cytometry. Results ATRA treatment stimulated B-cell specific signature in cHL cells including CD19,CD79a and CD79b while down-regulated their CD30 expression. Conclusions ATRA induces B-cell phenotype deficient cHL cells to regain their B-cell transcriptional program while abolishes their Hodgkin-specific machinery.

Epigenetic modification by 5-Aza/TSA treatment induces loss of B-cell phenotype in B-cell derived non-Hodgkin lymphoma / 中国病理生理杂志

AIM:To investigate influence of demethylation/acetylation by 5-Aza-2'-deoxycytidine/trichostatin A(5-Aza/TSA)treatment on B-cell specific phenotype of non-Hodgkin lymphoma cells.METHODS:CD19 promoter-driven reporter with NEO cassette was constructed to realize transfection and stable selection of Hodgkin and non -Hodgkin lymphoma cells.The exogenous CD19 promoter activity in both cell line clusters with and without 5-Aza/TSA treatment was detected and compared.The B-cell specific expression profiling in Eμ-myc transgenic mouse model developed lymphoma was isolated and identified.The effects of 5-Aza/TSA treatment on B-cell specific phenotype were analyzed.RESULTS:Epigenetic modification via 5-Aza/TSA repressed B-cell specific phenotype in B-cell-derived non-Hodgkin lymphoma cells. CONCLUSION:Epigenetic modification of pivotal master repressor genes plays an essential role in B -cell phenotype of both human and murine developed B-cell non-Hodgkin lymphoma cells.

Demethylation effect of emodin combined with 5AzA-cdR on tumor suppressor gene p16, RASSF1A and ppENK in subcutaneous xenografts of pancreatic cancer nude mice model / 中华胰腺病杂志

Objective To investigate whether emodin combined with 5AzA-cdR can enhance the demethylation of tumor suppressor genes p16,RASSF1A and ppENK in nude mice with subcutaneously transplanted pancreatic cancer.Methods Pancreatic cancer cells Panc1 burdened subcutaneous xenograft nude mice model was established,which were randomly divided into control group,emodin group,5AzA-cdR group and emodin combined 5AzA-cdR group (combined group).The growth of transplanted tumors wasobserved in each group.Methylation specific PCR (MSP) was used to detect the methylation levels of p16,RASSF1A and ppENK in the xenograft tumor tissue among three groups.The mRNA and protein expression of three tumor suppressor genes were detected by FQ-PCR and Western blotting,respectively.Results The weight of xenografts in the control group,emodin group,5AzA-cdR group,and combination group were (0.28 ±0.01),(0.17 ± 0.01),(0.12 ± 0.02),(0.08 ± 0.01)g,respectively.The tumor volume was (517 ±0.02),(382 ± 0.01),(232 ± 0.03),(169 ± 0.01) mm3.The methylation levels of p16 were 1.00 ± 0.00,0.89 ± 0.02,0.63 ± 0.02,and 0.19 ± 0.01;the methylation levels of RASSF1A were 1.00 ± 0.00,0.88 ± 0.02,0.51 ± 0.01,and 0.32 ± 0.01;the methylation degree of ppENK was 1.00 ± 0.00,0.92 ± 0.02,0.77 ± 0.02 and 0.31 ± 0.01,respectively.The expression of p16 mRNA was 1.00 ± 0.00,1.71 ±0.02,2.67 ± 0.02,3.81 ± 0.01.The expression of RASSF1A mRNA was 1.00 ± 0.00,1.92 ±0.02,2.73 ± 0.03,3.77 ± 0.01.The expression of ppENK mRNA was 1.00 ± 0.00,1.69 ± 0.03,2.17 ± 0.02 and 4.28 ± 0.01.The expression of p16 protein was 1.00 ± 0.00,1.71 ± 0.02,2.67 ± 0.02,3.81 ± 0.01;the expression of RASSF1A protein was 1.00 ± 0.00,1.92 ± 0.02,2.73 ± 0.03.3.77 ± 0.01;ppENK protein expression levels were 1.00 ±0.00,1.69 ±0.03,2.17 ±0.02,4.28 ±0.01.The weight and volume of xenografts in the three treatment groups were significantly smaller than those in the control group.The methylation of three tumor suppressor genes was lower than that of the control group,and the expression of tumor suppressor mRNA and protein was all significantly higher than the control group,which the combination drug group was also significantly stronger than that in emodin group and 5AzA-cdR group,and the differences were statistically significant (P ＜ 0.05 or ＜ 0.01).Conclusions The combination of emodin and 5AzA-cdR can enhance the demethylation effect of 5A6A-cdR on the tumor suppressor genes p16,RASSF1A and ppENK in the tumor tissue of pancreatic cancer xenograft model.

Effects of 5-Aza-2′-deoxycytidine on proliferation of human breast cancer cell line Hs578T and methylation of PRDM10 gene / 天津医药

Objective To investigate effects of 5-Aza-2′-deoxycytidine (5-Aza-CdR) on proliferation of human breast cancer cell line Hs578T,and the methylation status of PRDM10 gene in vitro in this cell line.Methods The human breast cancer cell line Hs578T was cultured with 1,3 and 5 μmol/L DNA methylation inhibitor 5-Aza-CdR respectively, and untreated cells were used as control.Cell proliferation was detected by MTT assay.Methylation-Specific PCR(MSP)was used to detect the methylation status of PRDM10 gene. The mRNA and protein expression levels of PRDM10 gene were detected by RT-PCR and Western blot assay. Results MTT results showed that the higher the concentration of 5-Aza-CdR,and the longer the treatment time,the more significant inhibitory effect on the proliferation of Hs578T cells.Compared with the control group(0 μmol/L),the proliferation of Hs578T was significantly inhibited after the treatment for 72 h in the 1 μmol/L group, and for 48 h in the 3 μmol/L and 5 μmol/L groups (P<0.05). MSP results showed that the higher the concentration of 5-Aza-CdR,the more significant demethylation of PRDM10.Results of RT-PCR and Western blot showed that the higher the concentration of 5-Aza-CdR, the higher the expression levels of mRNA and protein in PRDM10 (P<0.05).Conclusion 5-Aza-CdR could inhibit the cell proliferation of Hs578T,which might be related to the demethylation of PRDM10 gene in the cells.

Effect of 5-AZA-2'-dC on angiotensin Ⅱ-induced cardiomyocyte hypertrophy / 中华急诊医学杂志

Objective To investigate the effect of 5-AZA-2'-dC on Angiotensin Ⅱ (Ang Ⅱ)-induced cardiomyocyte hypertrophy.Methods Cultured cells derived from neonatal heart of rat were divided into 5 groups:normal control,hypertrophic group,5-AZA-2'-dC treatment group,and 5-AZA-2'-dC pretreatment group.Neonatal rat cardiomyocyte hypertrophic response was assayed by the size of cardiomyocytes and atrial natriuretic polypeptide (ANP) expressive level.The level of sarcoplasmic reticulum Ca2+ ATPase (SERCA2a),total calmodulin kinase Ⅱ (CaMK Ⅱ) and phospho-CaMK Ⅱ (p-CaMK Ⅱ) detected by Western blot.The intracellular calcium changes of cardiomyocytes were imaged by confocal fluorescent microscopy.Results Cells treated with Ang Ⅱ at 10-6 mol/L for 48 h were chosen as hypertrophic cardiomyocyte model.The mRNA expression and protein level of ANP were significantly decreased in the treatment and pretreatment groups compared with hypertrophic group.The protein level of SERCA2a was significantly decreased in the hypertrophic group,and increased in the treatment and pretreatment group compared with hypertrophic group.The protein level of SERCA2a was significantly decreased in the hypertrophic group,and increased in the treatment and pretreatment group compared with hypertrophic group,whereas phospho-CaMK Ⅱ showed an opposite change tendency.The time required for increasing and declining to half of the intracellular calcium peak value were both delayed in hypertrophic group,as the treatment and pretreatment groups showed shorter time required compared with hypertrophic group.Conclusion 5-AZA-2'-dC could inhibit Ang Ⅱ-induced cardiomyocyte hypertrophy which might be related to regulate SERCA2a expression.Increased SERCA2a expression may maintain the calcium homeostasis through shortening the time of transfer Ca2+ from the cytosol of the cell to the lumen of the sarcoplasmic reticulum.

Effects of DNA methylation inhibitor 5-Aza-2'-deoxycytidine on biological behavior of esophageal squamous carcinoma cells / 肿瘤研究与临床

Objective To investigate the effects of methylation inhibitor 5-Aza-2'-deoxycytidine (5-Aza-dC) on biological behavior of esophageal squamous carcinoma cell (ESCC) lines KYSE140 and KYSE150. Methods KYSE140 and KYSE150 cell lines were divided into the blank group, the control group and the experimental group. The cells in the blank group didn't do the treatment, and the cells in the control group were added to DMSO 2 μmol/L, while in the experimental group, cells were treated with different concentration (1, 2, 3 and 4 μmol/L) of 5-Aza-dC which affected respectively at different time (24, 48, 72 and 96 h). Cell proliferation was detected by using methyl thiazolyl tetrazolium (MTT) assay and the optimal drug concentration and time point were selected. Transwell assay was performed to detect the change of cell migration and invasion. Flow cytometry was used to observe the effects of drugs on cell apoptosis and cell cycle.The expression of PARP,Caspase-3,CCNB-1,and CCNE-1 were detected by Western blot. Results MTT result showed that the effective function time of 5-Aza-dC on KYSE140 and KYSE150 was 96 h at the concentration of 4 μmol/L. Under this condition, the cell ability of migration and invasion was decreased significantly. The migrated cell number of KYSE140 and KYSE150 respectively in the blank group, the control group and the experimental group was (193.3±8.6), (184.0±10.4), (61.7±7.1) and (112.0±6.4), (101.3± 7.9), (26.3±5.7). The invasive cell number was (47.3±7.3), (38.7±5.1), (8.0±3.9) and (83.3±6.8), (74.7±5.7), (21.0±2.7), respectively. The difference was statistically significant (P <0.05). Flow cytometry revealed that 5-Aza-dC increased the apoptosis of KYSE140 and KYSE150. The apoptosis rate of the blank group, the control group and the experimental group was (2.8±0.3) %, (11.2±0.7) %, (18.6±0.6) % for KYSE140 and (2.7±0.4)%,(9.8±0.4)%,(17.7±0.5)% for KYSE150.Compared with the other two groups,the cell number of G2/M phase in the experimental group was increased remarkably (P < 0.05). PARP and Caspase-3 were sheared evidently and the protein expression of CCNB-1 was up-regulated while the expression of CCNE-1 was down-regulated in the experimental group. Conclusion 5-Aza-dC can inhibit the proliferation and promote apoptosis of ESCC cells.

Preliminary Study on the Effect of 5-Aza-CdR on the Demethylation of RNF180 in Prostate Cancer Cell Line DU145 / 中国医科大学学报

Objective To investigate the mechanism and cause of the inactivation of tumor suppressor gene RNF180 in prostate cancer cell line by observing the effect of 5-Aza-CdR on the RNF180 gene in prostate cancer cell line DU145. Methods MTT method was adopted to study the effect of 5-Aza-CdR(0,1,2,5,10,15 and 20μmoI/L)on the proliferation of prostate cancer cells. Western blotting,real-time PCR,and methyla-tion specific PCR(MSP)were separately used to detect the expression of RNF180 in prostate cancer cells before and after the treatment of the most suitable drug concentration(5μmoI/L). Results In a certain range,the effect of 5-Aza-CdR on the proliferation of prostate cancer cell line DU145 was increased with the increase of drug concentration and the time of drug treatment(P<0.05). After the treatment of the most suitable drug concentration,the protein and mRNA expression of RNF180 in prostate cancer cells was significantly increased(P<0.05),but the methyla-tion of the promoter region was obviously decreased. Conclusion 5-Aza-CdR can reverse the methylation status of RNF180 gene in DU145 pros-tate cancer cell line,and relieve the silencing status of RNF180gene expression.

Influences of Pretreating with 5-Aza-2'-dc on the Reactive Oxygen Level and the Expression of Protein Bcl-2 and Bax in Paraquat Sensitized V79 Cells / 昆明医科大学学报

Objective To study the reactive oxygen level and the expression of anti-apoptotic protein Bcl-2 and pro-apoptotic protein Bax after treatment of DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine (5-Aza-2'-dc) and paraquat in V79 cells.Methods Cultured V79 cells were divided into 5-Aza-2'-dc treatment group (group A),paraquat treatment group (group B),5-Aza-2'-dc and paraquat treatment group (group C,V79 cells were pretreated with 5-Aza-2'-dc for 12h followed by exposure to paraquat for 12h) and control group (group D).Reactive oxygen level in V79 cells was measured by DCFH-DA flow cytometry and expression of Bcl-2 and Bax was detected by Western blot.Results Reactive oxygen levels and expression levels of Bcl-2 and Bax in V79 cells were significantly different (P＜0.05) in 5-Aza-2'-dc and paraquat treatment group (group C),compared with 5-Aza-2'-dc treatment group (group A),paraquat treatment group (group B) and control group (group D).Expression levels of Bcl-2 and the ratio of Bcl-2 and Bax were lower while reactive oxygen levels and expression levels of Bax were higher in group C than in groups A,B and D.Conclusion 5-Aza-2'-dc regulates DNA methylation by the imbalancing the reactive oxygen metabolism and apoptosis,thus up-regulating the toxic effect of paraquat on V79 cells.

The effects of 5-aza-2-deoxycytidine on RECK gene expression and invasion of salivary adenoid cystic car-cinoma cells / 实用口腔医学杂志

Objective:To investigate the effects of 5-aza-2′deoxycytidine(5-aza-dC),a DNA methyltransferase (DNMT)inhibitor, on the methylation status of the RECK gene and the invasion of salivary adenoid cystic carcinoma cell lines.Methods:Methylation-specific PCR,Western blot analysis and quantitative real-time PCR were used to investigate the methylation status of RECK gene and the expression of RECK mRNA and protein in SACC cell lines.The invasive ability of SACC cells was examined by transwell assay. Results:Promoter methylation was only found in ACC-Mcell line and not in ACC-2 cell line.Treatment of ACC-Mcells with 5-aza-dC partially reversed the hypermethylation status of the RECK gene and significantly enhanced the expression level of mRNA and pro-tein of RECK,suppressed ACC-Mcell invasive ability.Conclusion:5-aza-dC can inhibit ACC-Mcell invasion by reversal of hyperm-ethylation status of RECK gene.

Effects of 5-aza-2' -deoxycytidine combined with trichostatin A on cell proliferation and PDX-1 methylation on high glucose-induced toxicity in pancreatic β cells / 实用医学杂志

Objective To investigate the effects of 5-aza-2'-deoxycytidine (5-Aza-dC) alone or combined with trichostatin A(TSA) on cell proliferation, promoter methylation and mRNA expression level of PDX-1 gene in pancreatic β cells induced by high glucose toxicity. Method NIT-1 cells were treated in vitro by high glucose (33.3 mmol/L), then divided into five groups, control group, HG grpup, 5-Aza-dC treatment group, TSA interfere group and 5-Aza-dC + TSA group. Proliferation of NIT-1 cells, insulin secretion, promoter methylation and mRNA expression of PDX-1 gene were detected respectively. Results 5-Aza-dC and TSA alone or in combination could promote cell proliferation and recover insulin secretion in NIT-1 cells , could also reduce PDX-1 gene methylation and enhance expression of PDX-1 mRNA. Compared with single-treatment group , combined group was significantly different (all P < 0.05). Conclusion 5-Aza-dC and TSA could activate the expression of PDX-1 and, then recover insulin secretion in NIT-1 cells induced by high glucose. Combination of them had synergistic effect.

Toxic Effect of Paraquat on Sensitized V79 Cells Pretreated with 5-aza-2'-deoxycytidine / 昆明医科大学学报

Objective To study the effect of DNA methylation regulation on the toxic effect of paraquat on the sensitized V79 cells t pretreated with 5-aza-2'-deoxycytidine.Methods V79 cells were treated by 5-aza-2'-deoxycytidine (5-Aza-2'-dc) for 12h,which is a DNA methylation inhibitor,and then treated with paraquat for 12h.The morphological changes of V79 cells were observed by microscopy and the cell viability was determined by MTT assay and trypan blue staining method.Results Microscopic examination showed that the combination of 5-Aza-2'-dc and paraquat had stronger effect in inhibiting the growth of V79 cells(the cells became smaller and poorer adhensive ability) than single 5-Aza-2'-dc or paraquat.MTT assay showed that cell viability in the combination group (54.47 ± 3.04) ％ was significantly lower than the 5-Aza-2'-dc group (95.52 ± 0.90) ％ and paraquat group (89.68 ± 4.26) ％ (P＜0.05).Trypan blue staining assay showed that the death rate of ceils in the combination group (53.58 ± 1.57) ％ was significantly higher than the 5-Aza-2'-dc group (7.44 ± 2.31) ％ and paraquat group (12.90 ± 1.21) ％ (P＜0.05) Conclusion 5-Aza-2'-dc promotes V79 cells damage caused by paraquat.

The regulatory effect of 5-aza-2,-deoxycytidine in cervical cancer cells / 实用医学杂志

Objective To discuss the regulatory effect of 5-aza-2 ,-deoxycytidine on P16 and MGMT in cervical cancer cells. Methods After four kinds of cervical cancer cells (HeLa, SiHa, C33A and CaSki) were treated with 5-Aza-dC , MSP was used to detect the methylation variation of P16 and MGMT , and fluorogenic quantitative PCR and Western blot were employed for determination of P16 and MGMT expression. MTT and Annexin V-FITC/PI double staining were adopted for detection of cell proliferation and apoptosis. Results Both P16 and MGMT exhibited methylation in four kinds of cervical cancer cells , and after treatment with 5-Aza-dC ,their methylation levels were reversed. 5-Aza-dC was able to inhibit p16 and MGMT expression in the cervical cancer cells, and can also suppress cell proliferation and promote apoptosis. Conclusions Although methylation of P16 and MGMT are present in cervical cancer cells, their expression level was still high. Therefore, regulation of P16 and MGMT expression may be affected by other factors. 5-Aza-dC can suppress the growth of cervical cancer cells. Although 5-Aza-dC reverse the methylation levels of P16 and MGMT, it inhibits their gene expression. More experiments are needed to verify the hidden reasons and mechanisms.

Study of DNA demethylation acting on DNA methyltransferase gene and microRNA in B-cell acute lymphocytic leukemia cell line / 白血病·淋巴瘤

Objective To explore the function of 5-Aza-CdR in B-cell acute lymphocytic leukemia cell line NALM-6 and its influence on the expression of microRNA (miRNA) in the cells. Methods NALM-6 was treated with different concentrations of 5-Aza-CdR. Cell proliferation was detected by methyl thiazolyl tetrazolium (MTT) test, and DNA methyltransferase (DNMT) mRNA expression level was detected by reverse transcription PCR (RT-PCR). The expression changes of miRNA were detected by miScript miRNA PCR Array chip in cells after methylation. Results NALM-6 cell growth was inhibited by different concentrations of 5-Aza-CdR processing time, reaching to the maximum inhibitory rate was (74.163 ±0.381) %. 5-Aza-CdR affected concentrations was inversely proportional with expression level of DNMT mRNA. After 1 000 μmol/L of 5-Aza-CdR was dealed with cell 72 h, the relative expression of DNMT-1 was reduced to 0.453 ±0.021, DNMT-3L was 0.003±0.001, DNMT-3B was 0.395±0.019. MiScript miRNA PCR array sieved out 3 miRNA (miR-184, miR-23a-3p, miR-34a-5p) associated with DNA methylation. Conclusions 5-Aza-CdR down regulates the expression of DNMT gene in NALM-6 cells, and inhibits the proliferation of cells. MiR-184, miR-23a-3p and miR-34a-5p are related to DNA methylation in the occurrence and development of B-cell acute lymphocytic leukemia.

Effects of 5-aza-2′deoxycytidine on RECK gene expression and tumor invasion in salivary adenoid cystic carcinoma

Reversion-inducing cysteine-rich protein with kazal motifs (RECK), a novel tumor suppressor gene that negatively regulates matrix metalloproteinases (MMPs), is expressed in various normal human tissues but downregulated in several types of human tumors. The molecular mechanism for this downregulation and its biological significance in salivary adenoid cystic carcinoma (SACC) are unclear. In the present study, we investigated the effects of a DNA methyltransferase (DNMT) inhibitor, 5-aza-2′deoxycytidine (5-aza-dC), on the methylation status of the RECK gene and tumor invasion in SACC cell lines. Methylation-specific PCR (MSP), Western blot analysis, and quantitative real-time PCR were used to investigate the methylation status of the RECK gene and expression of RECK mRNA and protein in SACC cell lines. The invasive ability of SACC cells was examined by the Transwell migration assay. Promoter methylation was only found in the ACC-M cell line. Treatment of ACC-M cells with 5-aza-dC partially reversed the hypermethylation status of the RECK gene and significantly enhanced the expression of mRNA and protein, and 5-aza-dC significantly suppressed ACC-M cell invasive ability. Our findings showed that 5-aza-dC inhibited cancer cell invasion through the reversal of RECK gene hypermethylation, which might be a promising chemotherapy approach in SACC treatment.