Correlation between methylation level of and genes and aging in healthy individuals / 南方医科大学学报

OBJECTIVE@#To analyze the relationship between and gene methylation with aging in the general population.@*METHODS@#We collected peripheral blood samples from 284 male and 246 female healthy subjects for detection of methylation levels of and genes using quantitative methylation-specific PCR (qMSP). The relationship between the methylation levels of and genes and aging was analyzed using Spearman or Pearson correlation test.@*RESULTS@#We found a significant positive correlation between the methylation levels of the two genes in these subjects ( < 0.05). In the overall population as well in the female subjects, methylation was found to be inversely correlated with age ( < 0.05). The methylation levels of and genes were inversely correlated with TG, ApoE, Lp(a) and AST in the overall population ( < 0.05). In both the female and male subjects, the methylation levels of the two genes were inversely correlated with Lp(a) ( < 0.05). In the male subjects, methylation was inversely correlated with AST ( < 0.05), while methylation was inversely correlated with HDL and ApoE ( < 0.05). In the female subjects, methylation was positively correlated with LDL and inversely correlated with ApoE and AST ( < 0.05).@*CONCLUSIONS@#The methylation levels of and are closely related to age and the levels of multiple proteins in healthy subjects.

Association of CDKN2B-AS1 Polymorphisms with Premature Triple-vessel Coronary Disease and Their Sex Specificity in the Chinese Population / 生物医学与环境科学（英文）

OBJECTIVE@#The aim of this study is to establish whether cyclin-dependent kinase inhibitor 2B antisense RNA 1 (CDKN2B-AS1) gene polymorphisms are associated with premature triple-vessel disease (PTVD).@*METHODS@#Nine single-nucleotide polymorphisms (rs1063192, rs10757274, rs1333042, rs1333049, rs2285327, rs3217986, rs3217992, rs4977574, and rs9632884) were genotyped in 884 PTVD patients and 907 control subjects (males ⪕ 50 years old and females ⪕ 60 years old) using the improved multiplex ligase detection reaction method.@*RESULTS@#The allele frequencies of rs10757274 G, rs1333049 C, rs4977574 G (all P < 0.001), and rs3217986 G (P = 0.040) were significantly higher in the PTVD group than in the control group, but those of rs1063192 A, rs1333042 G, and rs9632884 C (all P < 0.001) were significantly lower in the former than in the latter. Logistic regression analysis revealed that homozygote AA of rs1333042 is associated with decreased risk for PTVD (OR = 0.42, 95% CI: 0.22-0.82, P = 0.011). In addition, the allele frequencies observed differed between genders. The G allele of rs3217986 was associated with increased risk for PTVD in male patients only (OR = 2.94, 95% CI: 1.27-6.80, P = 0.012) in the dominant model, and no positively mutated allele was found in female patients.@*CONCLUSION@#Polymorphisms of the CDKN2B-AS1 gene are associated with the incidence of PTVD in the Chinese population. Furthermore, the frequencies of mutated alleles differed between genders.

fundamental role played by cell cycle proteins in controlling cell proliferation in chronic hepatitis C virus infection

Background: examining the alteration of cell cycle genes in early hepatitis C virus [HCV] found that altered expression of mitotic checkpoint genes, MAD2L1, KNTC1, CDC16 and CDC34, KNTC1 known as "rough deal protein" [ROD] is part of a complex involved in elaborating an inhibitory signal due to improper chromosomal aligment during cell division

Aim of the work: attempt for the identification of proteins [genes], which act as predictive factors to identify patients with high risk of cell transformation and HCC development

Patients and Methods: fifty three patients with chronic HCV infection, age ranged between 18 and 58 years, time of assessment was before starting therapy of hepatitis C at the National Hepatology and Tropical Medicine Research Institute. Ten healthy individuals were included to serve as controls. All the patients and controls were subjected to the following: history, clinical examination, abdominal ultrasonography, and collection of blood samples for routine laboratory investigation; CBCs. Liver biopsy was done to all patients and controls, patients revealed mild fibrosis [Metavir fibrosis scores from F1 to F3]. Also, we used freshly frozen liver biopsies mRNA levels with perspective protein levels of four genes: P27, P15, KNTC1, MAD2L1

Results: significant association of P27, P15, KNTC1 and MAD2L-1 with the progression of liver fibrosis in chronic HCV liver biopsy was found

Conclusion: there is altered gene expression in HCV-associated liver disease

Recommendations: The emerging interest of hepatologists in the influence of genetic factors in HCV. Evaluation of the expression of key proteins related to the cell cycle and apoptosis in chronically infected patients with HCV would be of significance to understand disease pathogenesis, and will help in identifying novel prognostic indicators

Effect of phenelzine on the proliferation, apoptosis and histone methylation and acetylation of Molt-4 cells / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the effect of monoamine oxidase inhibitor phenelzine on proliferation, apoptosis and histone modulation in acute lymphoblastic leukemia cell line Molt-4 cells.</p><p><b>METHODS</b>The effect of Phenelzine on cell proliferation was detected by MTT. Apoptotic rate was measured by flow cytometry. The variation of apoptosis associated proteins Caspase-3, Bcl-2 and Bax, cyclin-dependent kinase inhibitor p21, tumor suppressor protein p15, and the expression level of histone methylation of H3K4, H3K9 and histone acetylation of H3, DNMT1 were detected by Western Blot.</p><p><b>RESULTS</b>① Molt-4 cell proliferation rates were (87.68±3.54)%, (67.84±3.24)%, (51.48±3.37)%, (28.72±2.56)% respectively after exposured to phenelzine at 5, 10, 15, 20 μmol/L for 24 h, P<0.05. ② After 10 μmol/L of phenelzine exposure for 24, 48, 72 h, cell proliferation rates were (67.84±3.24)%, (50.24±2.01)%, (40.31±2.25)%, P<0.05. ③ The apoptotic rates were (13.64±2.58)%, (31.24±3.42)%, (56.37±4.26)% after phenelzine treatment at 5, 10, 20 μmol/L for 24 h, which was concentration dependent. ④ Phenelzine could upregulate the expression of Bax, caspase-3, p21, and downregulate Bcl-2 expression. Phenelzine upregulated the methylation level of histone H3K4me1, H3K4me2 and histone acetylated H3, while it didn't change the level of histone H3K4me3, H3K9me1, H3K9me2. ⑤ Phenelzine inhibited DNMT1 expression and promoted p15 expression.</p><p><b>CONCLUSIONS</b>Phenelzine increased the methylation of histone H3K4me1, H3K4me2, acetylation of histone H3 and p21, and decreased the expression of DNMT1 and p15, and ultimately inhibited the proliferation and apoptosis of Molt-4 cells.</p>

Tal1 promotes proliferation of acute lymphoblastic leukemia Jurkat cells in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the role of Tal1 gene, which is aberrantly expressed in 40%-60% of patients with T lymphocytic leukemia (T-ALL), in the proliferation of T-ALL cells.</p><p><b>METHODS</b>We established stable Jurkat-siTal1 and Jurkat-T1 cell lines by trasnfecting T-ALL Jurkat cells with lentiviral vectors to knock-down or overexpress Tal1. Jurkat cells transfected with negative control siRNAs for Tal1 knock-down (Jurkat-mock1) and over-expression(Jurkat-mock2) served as the control cells. The proliferation of the cells lines was assessed using CCK-8 assay, and the cell cycle distribution was determined by flow cytometry. The mRNA and protein expressions of cyclin-dependent kinase inhibitor 2 (CDKN2A) and cyclin-dependent kinase inhibitor 1 (CDKN2B) were measured by real-time RT-PCR and Western blotting, respectively.</p><p><b>RESULTS</b>Jurkat-T1 cells showed more active proliferation in vitro than Jurkat-mock2 cells, while Jurkat-siTal1 cells showed slower growth than Jurkat-mock1 cells. In Jurkat-T1 cells, G0/G1 phase cells were decreased and S phase cells increased compared with Jurkat-mock2 cells, and Jurkat-siTal1 cells showed increased G0/G1 phase cells and decreased S phase cells compared with Jurkat-mock1 cells. Real-time RT-PCR and Western blotting showed that Tal1 inhibited the cellular expression of CDKN2A and CDKN2B at both mRNA and protein levels.</p><p><b>CONCLUSION</b>Tal1 promotes the growth and the transition from G0/G1 phase to S phase in T-ALL cells Jurkat by inhibiting the expressions of G0/G1 and S phase negative regulatory proteins CDKN2A and CDKN2B.</p>

High expression of p15 antisense RNA is a frequent event in acute myeloid leukemia / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To detect the presence of p15 antisense RNA(p15AS) in acute myeloid leukemia(AML).</p><p><b>METHODS</b>p15AS and p15 mRNA in two leukemia cell lines was detected with strand-specific primer RT-qPCR. To explore the connection between p15AS and AML, 43 patients with newly diagnosed AML and 21 patients with benign diseases (Iron deficiency anemia) as controls were enrolled. The expression level of p15AS in bone marrow cells derived from the patients and the controls were determined by strand-specific primer RT-qPCR, and its relationship with clinical features was analyzed.</p><p><b>RESULTS</b>The two AML lines displayed high p15AS and low p15 expression. Samples derived from the AML patients showed relatively increased expression of p15AS and down-regulated p15 expression in their bone cells. In contrast, the 21 controls showed high expression of p15 but relatively low expression of the p15AS. Compared with the normal controls, the expression levels of p15 protein were significantly lower among the AML patients (P<0.01). No relationships were detected between the level of p15AS and the patient's age, gender, FAB subtype, total white blood cell count, platelet count, proliferative degree of bone marrow cell and karyotype classification (P>0.05 for all comparisons).</p><p><b>CONCLUSION</b>High expression of p15 antisense RNA was frequently found among AML patients, and may play an important role in epigenetic silencing of p15.</p>

Genetic Basis of Gastric Cancer / 中国医学科学杂志(英文版)

Gastric cancer is the result of multiple risk factors, including environmental factors, genetic factors and the interaction between them. The environmental factors mainly include dietary, Helicobacter pylori infection and family history of gastric cancer. Genetic factors mainly refer to the susceptible genes that cause epigenetic alterations in oncogenes, tumor suppress genes, cell cycle regulators, DNA repair genes and signaling molecules. This paper summarizes the susceptible genes of gastric cancer and explores the genetic basis of it.

Methylation of the genes in the 9P21 region in children with acute myeloid leukemia / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the methylation rate of cyclin-dependent kinase inhibitor 2A (CDKN2A) and cyclin-dependent kinase inhibitor 2B (CDKN2B) in the 9P21 region in children with acute myeloid leukemia (AML) and the association of gene methylation with clinical features and outcomes.</p><p><b>METHODS</b>The clinical data of 58 children who were newly diagnosed with AML between January 2010 and December 2012 were retrospectively analyzed. Thirty-eight healthy children were recruited as the control group. Genomic DNA was extracted from bone marrow or peripheral blood of the 58 patients and 38 healthy children. The methylation status of CDKN2A and CDKN2B was analyzed by methylation-specific multiplex ligation-dependent probe amplification.</p><p><b>RESULTS</b>Gene methylation was not found in healthy children. Methylation probes of 44 patients were detected in 58 patients. The methylation of CDKN2A was detected with 136 bp and 237 bp methylation probes. The methylation of CDKN2B was detected with 130 bp, 210 bp, 220 bp, and 417 bp methylation probes. The methylation rate of CDKN2A was 5%, while the methylation rate of CDKN2B was 76%. The methylation detected by some probes was associated with sex, hemoglobin, and platelet count at the first visit.</p><p><b>CONCLUSIONS</b>The methylation of CDKN2B is a common event in children with AML, while the methylation of CDKN2A is relatively rare.</p>

Proliferative and invasive effects of inhibitors of kinase 4(P15(ink4b) and P16(ink4a)/CDKN2) gene activation on RKO human colorectal cancer cells / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To explore the proliferation and invasive effects of inhibitors of kinase 4(INK4)(P15(ink4b) and P16(ink4a)/CDKN2) gene protein activation on RKO human colorectal cell in vivo and in vitro.</p><p><b>METHODS</b>RKO human colorectal cell line was exposed to the specific DNA methyltransferase inhibitor 5-Aza-CdR and INK4(P15(ink4b) and P16(ink4a)/CDKN2) protein expression was detected by Western blotting. Soft agar cloning experiment and Transwell chamber assay were used to detect the proliferative and invasive ability in vitro. Tumorigenicity in nude mice was analyzed in vivo.</p><p><b>RESULTS</b>INK4(P15(ink4b) and P16(ink4a)/CDKN2) protein expression of RKO human colorectal cells after exposure to 1×10(-7), 5×10(-7) and 1×10(-6) mol/L 5-Aza-CdR concentrations(A, B, C groups) were 1.13, 1.38, 1.92 folds and 1.11, 1.45, 2.14 folds compared to positive control group respectively. Soft agar cloning experiment showed the number of cell colony significantly decreased from 36.8±5.1(positive control group) to 32.4±7.2, 21.3±5.4 and 19.5±6.4 (3 experiment groups, all P<0.05) respectively. Transwell chamber assay showed that migrated cell number in positive control group(67.4±7.2) was significantly higher than those of 3 experimental groups(35.3±4.6, 29.5±7.3 and 25.3±6.2, respectively). The tumor volume of metastasis model in nude mice was inhibited in experimental groups, but not significantly lower compared to control group (P>0.05). There were significant differences of tumor weight and inhibition rate between control group and 3 experimental groups in nude mice respectively(all P<0.01).</p><p><b>CONCLUSION</b>INK4(P15(ink4b) and P16(ink4a)/CDKN2) protein activation can inhibit tumor proliferation, migration and suppress the tumor formation ability.</p>

p15(INK4B) methylation on prognosis and response to decitabine in patients with MDS / 中华血液学杂志

<p><b>OBJECTIVE</b>To detect p15(INK4B) methylation levels and the kinetics of the methylation status before and after decitabine to explore its influences on prognosis and response to decitabine in myelodysplastic syndromes (MDS) patients.</p><p><b>METHODS</b>We examined 261 MDS patients (143 male and 118 female) with the median age of 52 years (32-78). Of them, 172 cases were low-risk group (low-risk 104 cases, intermediate-1 68 cases), 89 cases high-risk group (intermediate-2 52 cases, high risk 37 cases). Collections of bone marrow mononuclear cells of MDS patients and extracted the genomic DNA, the methylation status of p15(INK4B) was detected by methylation-specific PCR (MSP) method. Survival analysis was conducted according to the level of p15(INK4B) methylation in the cohort of patients. The kinetics of the methylation levels of p15(INK4B) in 58 MDS patients before and after 2 courses of decitabine have been assessed with the method of MSP.</p><p><b>RESULTS</b>The methylation level of p15(INK4B) in low-risk group patients was significantly lower than that in high-risk group (117.22 vs 157.63, P<0.05 ). The expected 2-year survival rate of p15(INK4B) methylation positive patients was lower than that of negative ones (91.8% vs 69.8%, P<0.05); the expected 2-year survival rate of p15(INK4B) methylation positive patients was shorter than that of negative ones in low-risk group（78.2% vs 92.0%, P<0.05）, meanwhile there was no significant difference in terms of expected 2-year survival rate and median expected survival between p15(INK4B) methylation positive and negative patients in high-risk group [35.6% vs 38.5%, (17.0±9.3) month vs (18.0±5.7) month, P>0.05]. Multivariate analysis showed p15(INK4B) methylation degree was an independent prognostic factor for overall survival. No statistical difference of overall response (OR) rates were found between p15(INK4B) methylation positive patients and negative patients before decitabine（65.9% vs 76.5%, P>0.05）, and complete remission (CR) rates between these two groups also showed no statistical difference（22.0% vs 29.4%, P>0.05）. p15(INK4B) methylation levels had no obvious change before and after treatment in decitabine responders（P>0.05）.</p><p><b>CONCLUSION</b>The survival of newly diagnosed MDS patients with positive p15(INK4B) methylation was comparatively shorter, but p15(INK4B) methylation had no influence on response to decitabine.</p>

Improved Therapeutic Effect against Leukemia by a Combination of the Histone Methyltransferase Inhibitor Chaetocin and the Histone Deacetylase Inhibitor Trichostatin A

SUV39H1 is a histone 3 lysine 9 (H3K9)-specific methyltransferase that is important for heterochromatin formation and the regulation of gene expression. Chaetocin specifically inhibits SUV39H1, resulted in H3K9 methylation reduction as well as reactivation of silenced genes in cancer cells. Histone deacetylase (HDAC) inhibitors inhibit deacetylases and accumulate high levels of acetylation lead to cell cycle arrest and apoptosis. In this study, we demonstrated that treatment with chaetocin enhanced apoptosis in human leukemia HL60, KG1, Kasumi, K562, and THP1 cells. In addition, chaetocin induced the expression of cyclin-dependent kinase inhibitor 2B (p15), E-cadherin (CDH1) and frizzled family receptor 9 (FZD9) through depletion of SUV39H1 and reduced H3K9 methylation in their promoters. Co-treatment with chaetocin and HDAC inhibitor trichostatin A (TSA) dramatically increased apoptosis and produced greater activation of genes. Furthermore, this combined treatment significantly increased loss of SUV39H1 and reduced histone H3K9 trimethylation responses accompanied by increased acetylation. Importantly, co-treatment with chaetocin and TSA produced potent antileukemic effects in leukemia cells derived from patients. These in vitro findings suggest that combination therapy with SUV39H1 and HDAC inhibitors may be of potential value in the treatment of leukemia.

Comparison of Methylation Profiling in Cancerous and Their Corresponding Normal Tissues from Korean Patients with Breast Cancer

BACKGROUND: Aberrant DNA hypermethylation plays a pivotal role in carcinogenesis and disease progression; therefore, accurate measurement of differential gene methylation patterns among many genes is likely to reveal biomarkers for improved risk assessment. We evaluated the gene hypermethylation profiles of primary breast tumors and their corresponding normal tissues and investigated the association between major clinicopathological features and gene hypermethylation. METHODS: A single reaction using methylation-specific multiplex ligation-dependent probe amplification was used to analyze the DNA methylation status of 24 tumor suppressor genes in 60 cancerous tissues and their corresponding normal tissues from patients with primary breast cancer. RESULTS: In cancerous breast tissues, 21 of 24 genes displayed promoter methylation in one or more samples. The most frequently methylated genes included RASSF1 (43.3%), APC (31.7%), CDKN2B (25.0%), CDH13 (23.3%), GSTP1 (16.7%), and BRCA1 (10%). APC was associated with lymph node metastasis, and BRCA1 was associated with negative estrogen receptor and negative progesterone receptor expression. In normal breast tissues, 8 of 24 tumor suppressor genes displayed promoter hypermethylation; CDKN2B (28.3%) and RASSF1 (8.3%) hypermethylation were most frequently observed. CONCLUSIONS: RASSF1 and CDKN2B hypermethylation in Korean breast cancer patients were the most frequent in cancerous tissue and corresponding normal tissue, respectively. Our data indicates that methylation of specific genes is a frequent event in morphologically normal breast tissues adjacent to breast tumors as well as the corresponding breast cancers. This study also suggests that gene methylation is linked to various pathological features of breast cancer; however, this requires confirmation in a larger study.

A high concentration of genistein down-regulates activin A, Smad3 and other TGF-beta pathway genes in human uterine leiomyoma cells

Previously, we found that high doses of genistein show an inhibitory effect on uterine leiomyoma (UtLM) cell proliferation. In this study, using microarray analysis and Ingenuity Pathways Analysis(TM), we identified genes (up- or down-regulated, > or = 1.5 fold, P < or = 0.001), functions and signaling pathways that were altered following treatment with an inhibitory concentration of genistein (50 microg/ml) in UtLM cells. Downregulation of TGF-beta signaling pathway genes, activin A, activin B, Smad3, TGF-beta2 and genes related to cell cycle regulation, with the exception of the upregulation of the CDK inhibitor P15, were identified and validated by real-time RT-PCR studies. Western blot analysis further demonstrated decreased protein expression of activin A and Smad3 in genistein-treated UtLM cells. Moreover, we found that activin A stimulated the growth of UtLM cells, and the inhibitory effect of genistein was partially abrogated in the presence of activin A. Overexpression of activin A and Smad3 were found in tissue samples of leiomyoma compared to matched myometrium, supporting the contribution of activin A and Smad3 in promoting the growth of UtLM cells. Taken together, these results suggest that down-regulation of activin A and Smad3, both members of the TGF-beta pathway, may offer a mechanistic explanation for the inhibitory effect of a high-dose of genistein on UtLM cells, and might be potential therapeutic targets for treatment of clinical cases of uterine leiomyomas.

Detection of methylation levels of multi-genes by real-time PCR in patients with myelodysplastic syndrome / 中华血液学杂志

<p><b>OBJECTIVE</b>To analyze the promoter methylation levels of p15, CDH1, DAPK and HICI genes of patients with myelodysplastic syndrome (MDS) and explore the relationship between the level of methylation and clinical features.</p><p><b>METHODS</b>DNA methylation levels of p15, CDH1, DAPK and HICI in peripheral blood (PB) or bone marrow (BM) samples from 52 MDS patients were detected by real-time quantitative PCR. The correlation of the methylation level with clinical features and hematological findings was analyzed. 38 de novo AML patients and 46 normal individuals served as controls.</p><p><b>RESULTS</b>The methylation levels of p15, CDH1, DAPK and HICI were 16.23 ± 21.69, 6.59 ± 9.39, 0.14 ± 0.11 and 7.81 ± 9.70 in BM, and 14.96 ± 20.16, 6.00 ± 9.26, 0.12 ± 0.14 and 6.74 ± 9.72 in PB, respectively from 18 MDS patients, and the difference between BM and PB was not statistically significant (P > 0.05). The methylation levels of p15 (14.70 ± 18.17) and CDH1 (6.61 ± 8.79) genes in high risk (RAEBI/II) MDS were significantly higher than in low risk (RCMD/RARS/5q-, p15: 1.99 ± 1.59, CDH1: 1.23 ± 1.14 and RCMD, p15: 3.02 ± 3.42, CDH1:1.53 ± 2.06) MDS or control (p15: 1.69 ± 1.82, CDH1: 1.01 ± 1.12) (P < 0.05). The methylation levels of DAPK gene had no difference among subtypes of MDS, and that of HIC1 gene only differed between RAEB I/II (9.16 ± 11.95) and control (2.49 ± 2.26) (P = 0.042). The difference of methylation levels of p15, CDH1, DAPK and HICI in BM was statistically significant among subtypes of MDS (P = 0.001, 0.003, 0.039, 0.023, respectively). And so did of p15 and DAPK in PB (P = 0.013, 0.006, respectively). The methylation level of p15 and CDH1 was significantly correlated with IPSS classification and blasts percentage in BM.</p><p><b>CONCLUSIONS</b>p15 and CDH1 genes are special hypermethylation genes in MDS. Methylation level of HIC1 gene showed an upward tendency from low risk to high risk MDS.</p>

mRNA expression and methylation status of p15 promoter in mouse bone marrow cells exposed to 1,4-benzoquinone / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To detect the expression and the CpG island methylation status of tumor suppressor gene p15 after exposure to 1,4-benzoquinone (1,4-BQ) in primary cultivated C57BL/6J mouse bone marrow cells in vitro.</p><p><b>METHODS</b>The mouse bone marrow cells were isolated in vitro. The effect of 0, 0.1, 1, 5, 10, 20, and 40 µmol/L 1,4-BQ on cell viability (CKK-8) was detected. 0, 0.1, 1, 10 µmol/L 1,4-BQ were used to intoxicate the mouse bone marrow cells for 24 h; Real-time PCR was employed to analyze the mRNA expression level of p15; The bisulfite sequencing PCR (BSP) was used to look into the methylation status of CpG islands in p15 promoter region.</p><p><b>RESULTS</b>1,4-BQ exhibited dose-dependent toxicity to mouse bone marrow cells, and the LC(50) was 8.3 µmol/L (95%CI: 4.6 - 10.6 µmol/L). The mRNA expression of p15 in 10 µmol/L group was only equivalent to 43% of control group. Compared with control group, the decrease of p15 mRNA expression in1 and 10 µmol/L concentration were obvious, and the differences had statistical significance (P < 0.05 or P < 0.01). BSP sequencing results were same between the exposure groups and control group, the 56 CpG sites on CpG islands remained in the state of unmethylated.</p><p><b>CONCLUSION</b>mRNA expression of p15 gene decreases after exposure to 1,4-BQ, but the CpG islands methylation status in promoter is not affected, suggesting that methylation does not participate in 1,4-BQ-mediated p15 gene expression decrease, other effect mechanisms still need to be investigated.</p>

Phenylhexyl isothiocyanate induces gene p15 re-expression by regulating histone methylation and DNA demethylation in Molt-4 cells / 中国实验血液学杂志

This study was aimed to investigate the regulatory effect of phenylhexyl isothiocyanate (PHI) on methylation of histone H3K4, H3K9 and demethylation of p15 gene in acute leukemia cell line Molt-4, and to explore the possible mechanism inducing re-expression of silent gene. The methylation status of histone H3K4, H3K9 and the expression of P15 protein in the Molt-4 cells treated with PHI were detected by Western blot; the methylation status of p15 gene in the Molt-4 cells before and after treatment with PHI was determined by methylation specific polymerase chain reaction (MSP); the expression level of p15 gene mRNA in Molt-4 cells treated with PHI was assayed by semiquantitative reverse transcription-PCR. The results indicated that the PHI could increase methylation of histone H3K4 and decrease methylation of histone H3K9 in concentration-and time-dependent manners. After treatment of Molt-4 cells with PHI for 5 days, the methylation of p15 gene was reduced, the significant hypermethylation of p15 gene was reversed, the silenced p15 gene re-expressed; the expressions of p15 mRNA and P15 protein were enhanced in concentration-dependent manner. It is concluded that probably through specifically regulating the methylation level of histone H3K4 and H3K9, the PHI causes the changes of chromosome space structure and results in the demethylation of CPG island in p15 gene, thereby induces the re-expression of p15 gene which was silenced.

Inhibitory effect of transforming growth factor-β(1) on oral squamous cell carcinoma brain metastasis Tb cell line / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the inhibitory effect of transforming growth factor (TGF)-β₁ on oral squamous cell carcinoma (OSCC) Tb cell line.</p><p><b>METHODS</b>Cell counting method was used to examine the inhibitory effect of TGF-β₁ on Tb cell and flow cytometry (FCM) assay performed to measure the changes of cell cycle. Superarray was used to screen the changing expression of genes in TGF-β₁/Smads signaling pathway.RT-PCR method was used to detect the results of Superarray.</p><p><b>RESULTS</b>TGF-β₁ showed significant inhibiting effect on OSCC Tb cell line. TGF-β₁ blocked the cell cycle at G₁ phase. The expression level of activin receptor-like kinase-1 (ACVRL-1), anti-mullerian hirmine (AMH), cyclim-dependent kinase inhibitor-2B (CDKN-2B) and transforming growth factor-beta-indnced factor (TGIF) was higer in the cells treated with TGF-β₁ than in control, while TDGF-1 expression was down-regulated. ACVRL-1 and CDKN-2B gene expression was consistent with the results of Superarray.</p><p><b>CONCLUSIONS</b>TGF-β₁ can inhibit the growth of OSCC Tb cell line. The mechanism may be related to the regulation of cell cycle and the expression of ACVRL-1 and CDKN-2B in TGF-β₁-Smads signaling pathway.</p>

Effect of Oviductus Ranae on Cyclin D1, CDK6 and P15 expressions in the liver tissue of aged male rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of Oviductus Ranae (OR) on the expressions of CyclinD1, CDK6 and P15 in the liver of aged male rats.</p><p><b>METHODS</b>Eighteen male SD rats were randomly divided into 3 equal groups, namely the OR group, VE group and ageing model group. The rats received subcutaneous injection of D-galactose for 6 weeks to establish the aging models, and another 6 rats were injected daily with normal saline (NS) to serve as the normal control group. From the third week of the experiment, the rats were given oral OR or Vitamin E (VE) accordingly till the sixth week. After completion of the drug administration, all the rats were sacrificed for detecting the expressions of CyclinD1, CDK6 and P15 in the liver tissue by Western blotting.</p><p><b>RESULTS</b>The relative expression levels of CyclinD1, CDK6 and P15 in the liver of the rats in the OR group were 41.73-/+0.54, 23.29-/+0.30 and 1.49-/+0.30, respectively, significantly up-regulated as compared with those in the ageing model group (P<0.01). The expressions of the proteins were obviously down-regulated in the model group in comparison with those in the normal control group.</p><p><b>CONCLUSIONS</b>OR treatment can lower the expressions of Cyclin D1 and CDK6 in the liver to enhance the liver cell proliferation in aged male rats. OR also promotes the expression of P15 through a feedback mechanism to prevent excessive proliferation of the cells. The effect of OR against ageing is mediated possibly by up-regulation of the proteins associated with the cell proliferation in the liver, a mechanism different from that of VE.</p>

Phenylhexyl isothiocyanate induces gene p15 demethylation by down-regulating DNA methyltransferases in Molt-4 cells / 药学学报

This study is to investigate the effect of phenylhexyl isothiocyanate (PHI), which has been proved to be a novel histone deacetylase inhibitor (HDACi) recently, on gene p15 de novo expression in acute leukemia cell line Molt-4, and to further study its potential mechanism. Modified methylation specific PCR (MSP) was used to screen p15-M and p15-U mRNA. DNA methyltransferasel (DNMT1), 3A (DNMT3A), 3B (DNMT3B) and p15 mRNA were measured by RT-PCR. P15 protein was detected by Western blotting. Hypermethylation of gene p15 was reversed and activation transcription of gene p15 in Molt-4 was de novo after 5 days exposure to PHI in a concentration dependent manner. DNMT1 and DNMT3B were inhibited by exposure to PHI for 5 days (P < 0.05). Alteration of DNMT3A was not significant. It is showed that PHI could reverse hypermethylation of gene p15 and transcriptional activation of gene p15 is de novo by PHI. It may result from down-regulating DNA methyltransferases, DNMT1 and DNMT3B, or up-regulating the histone acetylation that allows chromatin unfolding and the accessibility of regulators for transcriptional activation in the p15 promoter.

Synergistic effects of VPA and As2O3 on Molt-4 cells in vitro and its possible mechanisms / 中国实验血液学杂志

This study was purposed to investigate the synergistic effects of sodium valproate (VPA) and As2O3 on the proliferation of Molt-4 cells in vitro and its possible mechanisms. Cell viability and growth curve were assessed by the MTT assay. The synergistic activity in combination of 2 drugs was determined by the Q format. The expression levels of p15, DNA methyltransferase 1 (DNMT-1), DNMT3A and DNMT 3B mRNA were detected by RT-PCR and the methylation level was detected by hn-MSPCR. The results indicated that the VPA and As2O3 both inhibited proliferation of Molt-4 cells. The combination of two drugs showed an additive effect (values of Q were>or=0.85). The inhibitory rate in combination of 5 mmol/L of VPA with 10 micromol/L of As2O3 was (70.31+/-2.54)%. The p15 gene in Molt-4 cell line failed to express due to its hypermethylation. The level of p15 gene mRNA expression increased significantly after exposure to VPA in combination with As2O3 for 48 h. As compared with control group, the expression of DNMT-1 was down-regulated in a dose-dependent manner, whereas DNMT3A had no significant differences from the control. The level of expression of DNMT3B seemed to decrease at 10 mmol/L concentration. There were significant differences between the combination of the two drugs and the control group. The gray value of methylated bands decreased after the treatment of VPA alone and in combination with As2O3 in a dose-dependent manner. It is concluded that VPA induces demethylation of p15 INK4B gene by inhibiting the DNMT-1 and DNMT3B gene activities, which up-regulates the p15 gene, recovers its activity. The combination of VPA with As2O3 has the synergistic additive effect on the inhibition of cell viability, so that VPA can reduce the side effect of As2O3 on liver function, which would be verified in the clinical practice.