Effect of Nucleolin on Lymphoma Proliferation by Regulating Thymidine Kinase 1 / 中国实验血液学杂志

OBJECTIVE@#To investigate the mechanism of nucleolin (NCL) involved in lymphoma proliferation by regulating thymidine kinase 1 (TK1).@*METHODS@#Twenty-three patients with diffuse large B-cell lymphoma (DLBCL) were selected and divided into initial treatment group (14 cases) and relapsed/refractory group (9 cases). Serum TK1 and C23 protein in peripheral blood mononuclear cells were detected. Cell models of CA46-NCL-KD (CA46-NCL-knockdown) and CA46-NCL-KNC (CA46-NCL-knockdown negative control) were established by lentivirus vector mediated transfection in Burkitt lymphoma cell line CA46. The half maximal inhibitory concentration (IC50) of CA46-NCL-KD, CA46-NCL-KNC, and CA46 to adriamycin were detected by cell proliferation assay (MTS). The expression of NCL mRNA and protein in CA46-NCL-KD and CA46-NCL-KNC cells were dectected by Q-PCR and Western blot, respectively. The cell cycle of CA46-NCL-KD, CA46-NCL-KNC, and CA46 cells were detected by flow cytometry. The expression of TK1 protein in CA46-NCL-KD and CA46-NCL-KNC cells was detected by an enhanced chemiluminescence (ECL) dot blot assay.@*RESULTS@#The level of serum TK1 in the initial treatment group was 0.43(0-30-1.01) pmol/L, which was lower than 10.56(2.19-14.99) pmol/L in the relapsed/refractory group (P<0-01), and the relative expression level of NCL protein in peripheral blood was also significantly lower. The IC50 of CA46-C23-KD cells to adriamycin was (0.147±0.02) μg/ml, which was significantly lower than (0.301±0.04) μg/ml of CA46-C23-KNC cells and (0.338±0.05) μg/ml of CA46 cells (P<0.05). Compared with CA46-NCL-KNC cells, the expression of NCL mRNA and protein, TK1 protein decreased in CA46-NCL-KD cells, and the proportion of S phase and G2/M phase also decreased, while G0/G1 phase increased in cell cycle.@*CONCLUSION@#The increased expression of NCL in DLBCL and CA46 cells indicates low sensitivity to drug. NCL may participate in regulation of lymphoma proliferation by affecting TK1 expression, thereby affecting the drug sensitivity.

PLK1 Expression in Mantle Cell Lymphoma and Its Clinical Significance / 中国实验血液学杂志

OBJECTIVE@#To explore the expression level of PLK1 in mantle cell lymphoma(MCL), and the effect of silencing PLK1 gene by RNA interference on the cell proliferation, apoptosis, and cell cycle.@*METHODS@#S-P immunohistochemistry technique was used to detect the expression of PLK1 in tissues of 42 patients with MCL and 30 patients with reactive proliferative lymphodenitis(RPL), their expression levels were compared and analyzed. The Jeko-1 cells were transfected with lentivirus contaiming PLK-1 shRNA, then the mRNA and protein expression of PLK-1 was detected by real-time guantitative PCR and Western blot nespectively, and the silencing efficacy of PLK-1 shRNA was identificd. The cell proliferation was detected by CCK method, the cell apoptosis was detected by Annexin V/PI double staining, the cell cycle was detected by PI single staining, the changes of apoptosis-related proteins BAX, BCL-2 and Caspase 3 were detected by Western blot.@*RESULTS@#The positive expression rate of PLK-1 in tissue of MCL patients was 66.67%(28/42), which was significanfly higher than 20%(6/30) in tissue of RPL patients (P＜0.05). The PLK-1 positive expression correlated with B symptom, IPI score, Ann-Arbor stage(P＜0.05). After infection of Jeko-1 cells with lentivirus containing PLK-1 shRNA for 72 hours, the mRNA and protein expressions of PLK-1 were significantly down-regulated(P＜0.05), the proliferation rate of cells in group of PLK-1 shRNA was significanly lower than that in control and Neg shRNA groups(P＜0.05); the apoptosis rate of cells in PLK-1 shRNA group was (27.42±3.44)%, which was significantly higher than that in control group (1.23±0.42)% and Neg shRNA group (2.07±0.58) % (P＜0.05). The cell cycle analysis showed that the cell ratio in G/M phase of PLK-1 shRNA group was (27.21±3.59) %, which was higher than that in control group (13.28±2.63)% and Neg shRNA group (14.34±2.37) %. The detection of apoptosis-related proteins showed that the expression of BAX was up-regulated, the expression of BCL-2 was down-regnlated and the expression of caspase 3 was up-regulated.@*CONCLUSION@#The PLK-l overexpression appears in tissue of MCL patients. The silencing PLK-1 gene can inhibit the proliferation of Jeko-1 cells, induce the apopotosis of Jeko-1 cells and arrestes cell cycle in G/M phase.

Inhibitory effect of VPA on multiple myeloma U266 cell proliferation and regulation of histone acetylation / 中国实验血液学杂志

This study was aimed to investigate the effects of sodium valproate (VPA) on the proliferation and regulation of histone acetylation of multiple myeloma cell line U266. U266 cells were treated with VPA. Cell proliferation was determined by CCK-8 assay, and cell cycle were analyzed by flow cytometry (FCM). The expression level of HDAC1 mRNA was detected by RT-PCR, and the protein levels of HDAC1 and histone H3, H4 acetylation was detected by Western blot. The results showed that the VPA inhibited the proliferation of U266 cells in concentration-and time-dependent manners.After exposure to different concentrations of VPA for 48 hours, the proportion of G(0)/G(1) cells increased, while the proportion of S phase cells decreased. The cell cycle was arrested obviously in G(0)/G(1) phase (p < 0.05). The expression of HDAC1 mRNA was inhibited, and the protein level of HDAC1 was down-regulated, while the histone H3/H4 acetylation was up-regulated in U266 cells. It is concluded that the VPA can inhibit cell proliferation of U266 and induce G(0)/G(1) phase arrest. The increase of histone H3/H4 acetylation resulting from inhibiting HDAC1 by VPA might be considered as a possible mechanism.

Investigation on the mechanisms of p15INK4B gene demethylation by valproate in Molt-4 cells / 中华血液学杂志

<p><b>OBJECTIVE</b>To study the antitumour effects of sodium valproate (VPA) on the proliferation, differentiation and cell cycle of Molt-4 cell and to investigate its demethylation mechanisms.</p><p><b>METHODS</b>After Molt-4 cells trated with VPA at different concentrations, cell viability and growth curve were assessed by MTT assay. Cell cycle changes were analyzed by flow cytometry. The expression level of p15, DNA methyltransferase 1 (DNMT-1), DNMT3A and 3B mRNA were detected by RT-PCR and the methylation level was detected by hn-MSPCR.</p><p><b>RESULTS</b>VPA significantly inhibited the proliferation of Molt-4 cells. After 48 h culture with 5.0 mmol/L VPA, the percentages of Molt-4 cells in G(0)/G(1) phase was (66.87 ± 3.31)% and in S phase was (8.47 ± 2.56)%, while in control group, the cells in G(0)/G(1) phase increased and in S phase decreased significantly. The p15 gene in Molt-4 cells failed to express due to its hypermethylation. The expression level of p15 gene mRNA increased significantly after exposure to VPA for 48 h. As compared with control group, the expression of DNMT-1 was down-regulated in a dose-dependent manner. The expression level of DNMT3B decreased at 10.0 mmol/L concentration.</p><p><b>CONCLUSION</b>VPA has a demethylation effect on p15 INK4B gene by inhibiting the DNMT-1 and DNMT3B gene activities to recover p15 gene activity, which arrests Molt-4 cell in G(0)/G(1) phase.</p>

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.