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.

Effects of baicalin on CA46 cell proliferation inhibition and apoptosis induction / 中国病理生理杂志

AIM:To investigate the effects of baicalin on proliferation inhibition and apoptosis induction in human Burkitt lymphoma cell line CA46 and to explore its underlying mechanisms.METHODS:CA46 cells were exposed to baicalin at different dosages and its proliferation inhibition was detected by MTT assay.The ability of baicalin to induce CA46 cell apoptosis was examined by Annexin V-FITC/PI double staining analysis,TUNEL labeling method and DNA fragmentation.The mRNA expressions of c-myc and bcl-2 were detected by RT-PCR,and the protein expressions of c-Myc,Bcl-2,caspase-3 precursor(procaspase-3) and poly ADP-ribose polymerase(PARP) were detected by Western blotting.RESULTS:Baicalin remarkably inhibited the CA46 cell proliferation,with an IC50 value of 10 ?mol/L.Apoptosis was remarkably induced by baicalin in a dose-dependent manner,and its earlier and later stages were detected by annexin V-FITC/PI double staining analysis,TUNEL labeling method and DNA fragmentation,respectively.Furthermore,RT-PCR showed that the mRNA expressions of c-myc and bcl-2 in treated CA46 cells decreased in a time-dependent manner.Western blotting showed that the protein expressions of c-Myc,Bcl-2,procaspase-3 and PARP(116 kD) in baicalin treated CA46 cells were down-regulated in a time-dependent manner,while the expression of PARP(85 kD) was up-regulated.CONCLUSION:Baicalin efficiently induces proliferation inhibition and apoptosis in CA46 cells,which may be related with the down-regulation of c-Myc and Bcl-2 expressions,as well as the up-regulation of caspase-3 activity.