The effect of apoptosis induced by IL-21 in SUDHL-4 cell line and its mechanism / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the apoptosis effect of diffuse large B-cell lymphoma cell line (DLBCL) SUDHL-4 induced by IL-21 and its related mechanism.</p><p><b>METHODS</b>SUDHL-4 cells were treated with IL-21 at different concentration (1000 ng/ml, 100 ng/ml, 10 ng/ml, 1 ng/ml) for 24 h, 48 h, 72 h, respectively. The inhibitory rate of cell proliferation was detected by CCK-8 assay. The cell growth curves were drawn and half inhibitory concentration (IC(50)) values were calculated. The cell apoptosis were detected by flow cytometry (FCM), the expression of the caspase-9, caspase-3, cleaved caspase-3, Bcl-2, Bcl-XL, Bid, Bax and c-myc protein in SUDHL-4 cells treated with IL-21 by western blot, the mRNA expression of Bcl-2, Bcl-XL, Bid, Bax, c-myc by Survivin gene with RT-PCR.</p><p><b>RESULTS</b>IL-21 markedly inhibited SUDHL-4 cell growth in a time- and dose-dependent manner. The 48 hIC(50) was 140.9ng/ml; The FCM showed that the apoptosis proportion of SUDHL-4 cells treated with 100 ng/ml of IL-21 apoptosis (AnnexinV-FITC(+) positive cells) gradually increased (48 h: 19.7 ± 2.3%). The protein expression of caspase-9, caspase-3, Bcl-2 and Bcl-XL decreased in a time-dependent manner. The Bax and c-myc protein markedly increased, but the Bid protein level did not change. IL-21 up regulated c-myc and Bax gene expression, however down regulated Bcl-2 and BCL-XL gene expression, but the gene expression of Bid and Survivin hadn't been changed significantly.</p><p><b>CONCLUSIONS</b>IL-21 can inhibit proliferation and induce apoptosis of SUDHL-4 cell. The mechanism may involve in endogenous mitochondrial pathway mediated by the c-myc and the Bcl-2 genes.</p>

Silencing of survivin gene in Jeko-1 cell line with small interfering RNA / 中国实验血液学杂志

This study was aimed to investigate the impact of specific siRNA on survivin gene in transfected lymphoma cell line and provide experimental evidences for future treatment of mantle cell lymphoma. The small interfering RNA (siRNA) targeted survivin mRNA was synthesized in vitro and was transfected into Jeko-1 that showed high survivin expression in mRNA level. The levels of survivin mRNA and protein expression were detected by quantitative reverse transcription polymerase chain reaction (RT-PCR) and Western blot respectively. The apoptosis effect was examined by calculating the ratio of Annexin V-FITC/PI positive cells using flow cytometry. The inhibition of cell proliferation was assayed with CCK-8 reagent after transfection. The results showed that expression of survivin mRNA was markedly suppressed by the siRNA. The relative expression levels were 0.49 ± 0.03, 0.38 ± 0.02 and 0.17 ± 0.02 at time points of 24, 48 and 72 h respectively, compared with the control group; the inhibitive rates of cell proliferation were (31.2 ± 2.1)%, (43.3 ± 3.4)% and (52.6 ± 2.5)%; the apoptotic rates of cells were (6.3 ± 0.5)%, (13.5 ± 1.1)% and (23.6 ± 1.6)% respectively; survivin protein expression levels were gradually reduced. It is concluded that the siRNA targeting survivin down-regulates the expressions of survivin mRNA and protein evidently. The siRNA of survivin displays the potent ability to inhibit the proliferation of lymphoma cell line Jeko-1; survivin may become a potential molecular target for the therapy of lymphoma in the future.

Study of hypermethylation of SOCS gene in typical myeloproliferative disease / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the clinical role of hypermethylation of suppressor of cytokine signaling (SOCS) on typical myeloproliferative disease (MPD) patients and its mechanism.</p><p><b>METHODS</b>Methylation specific PCR was used to detect SOCS1, 2, 3 methylation, direct DNA sequencing was performed to detect JAK2V617F mutation, real-time fluorescence quantitative PCR were applied to evaluate transcriptional activity of SOCS1, 2, 3.</p><p><b>RESULTS</b>Among 100 MPD patients, hypermethylation of SOCS1 was detected in 27 (27%), hypermethylation of SOCS2 in 9 (9%), hypermethylation of SOCS3 in 34 (34%); JAK2V617F mutation in 64 (64%). Hypermethylation of SOCS1, 3 greatly inhibited gene expression compared with unmethylated ones (P < 0.05). Presence of JAK2V617F mutation markedly down-regulated SOCS1, 3 gene mRNA expression compared with wild JAK2V617F (P < 0.05).</p><p><b>CONCLUSION</b>Hypermethylation of SOCS1, 3 and JAK2V617F mutation exist in MPD, which inhibited SOCS1, 3 gene expression. SOCS hypermethylation and JAK2V617F mutation can activate JAK-STAT signaling pathways, these observations may provide a potential therapeutic direction.</p>