miR-141-3p attenuates RSL3-induced ferroptosis and intestinal epithelial-mesenchymal transition via directly inhabits ZEB1 in intestinal Behçet's syndrome.

The aims of this study were to investigate whether the ferroptosis is involved in intestinal Behçet's syndrome (IBS), and to identify if miR-141-3p could attenuate RAS-selective lethal 3 (RSL3)-induced ferroptosis and intestinal epithelial to mesenchymal transition (EMT) via directly inhabits zinc fnger E-box binding homeobox 1 (ZEB1). The expressions of ferroptosis-related proteins in the intestinal tissues of patients with IBS were investigated by immunohistochemistry and quantitative real-time PCR (qRT-PCR). Malondialdehyde (MDA) contents of the intestinal tissues and cells were detected. Serum from IBS patients and RSL3 were co-cultured with intestinal epithelial cells in vitro. In order to investigate whether RSL3-induced ferroptosis can be ameliorated by miR-141-3p, the intestinal epithelial cells were firstly stimulated with RSL3 and then incubated with miR-141-3p mimics. Western blot was used to measure the expression of EMT and ferroptosis-related proteins. Expression of GPX4 (22.51% ± 2.05%, 51.75% ± 3.47%, t = - 7.77, p = 0.000) and xCT (17.49% ± 1.57%, 28.73% ± 1.75%, t = - 4.38, p = 0.003) were significantly lower in intestinal mucosal tissues of patients with IBS compared with HC group. Compared with the HC samples, the IBS specimens had significantly higher MDA (t = 4.32, p = 0.01). Moreover, the relative mRNA levels of ferritin light chain (FTL) (t = 4.07, p = 0.02) and ferritin heavy chain (FTH) (t = 8.82, p = 0.001) in the intestinal tissues were significant higher in IBS patients than in HC group. Serum from IBS patients could induce intestinal epithelial cell ferroptosis in vitro. Moreover, miR-141-3p could attenuate intestinal epithelial cell ferroptosis-induced by RSL3 and intestinal EMT via targeting ZEB1 in vitro. Ferroptosis were induced in patients with IBS. Moreover, the serum from IBS patients could induce ferroptosis in vitro. miR-141-3p could attenuate intestinal epithelial cell ferroptosis and intestinal EMT via targeting ZEB1. Therefore, miR-141-3p may open new avenues for the treatment of IBS in the future. Key Points • Ferroptosis in IBS is first reported in this study. • In this study, we explored that the serum from IBS patients could induce ferroptosis in vitro and miR-141-3p could attenuate intestinal epithelial cell ferroptosis and intestinal EMT via targeting ZEB1.

Risk factors for the flare of systemic lupus erythematosus and its influence on prognosis: a single-center retrospective analysis.

OBJECTIVES: To explore the risk factors for systemic lupus erythematosus (SLE) flare and their impact on prognosis. METHODS: The clinical characteristics, laboratory results, and treatment plans of 121 patients with SLE flare were retrospectively analyzed. Ninety-eight SLE outpatients with sustained remission during the same period were selected as controls. Logistic multivariate regression analysis was employed to screen for risk factors for SLE flare. RESULTS: Infection, thrombocytopenia, arthritis, anti-nucleosome antibodies positive, anti-ß2-glycoprotein I (IgG) antibodies positive, and patient's self-discontinuation of medicine maintenance therapy might be risk factors for SLE flare. Patients who discontinued medicine maintenance therapy by themselves had a significantly higher rate of severe SLE flare than patients with regular medicine maintenance therapy (P = 0.033). The incidence of anemia associated with SLE (P = 0.001), serositis (P = 0.005), and pulmonary hypertension (P = 0.003) in patients who discontinued medicine maintenance therapy were significantly higher than patients with regular medicine maintenance therapy. SLE patients with regular medicine maintenance therapy for less than 3 years had a higher risk of pulmonary hypertension than those with regular medicine maintenance therapy longer than 3 years (P = 0.034). CONCLUSIONS: The accompanying thrombocytopenia, arthritis, anti-nucleosome antibodies positive and anti-ß2-glycoprotein I (IgG) antibodies positive at the onset of SLE may affect the prognosis of SLE. Patient's self-discontinuation of medicine maintenance therapy is the main cause of SLE flare, which may induce severe flare in SLE patients and lead to a significantly higher incidence of pulmonary hypertension.

Risk factors for the flare of systemic lupus erythematosus and its influence on prognosis: a single-center retrospective analysis

Abstract Objectives: To explore the risk factors for systemic lupus erythematosus (SLE) flare and their impact on prognosis. Methods: The clinical characteristics, laboratory results, and treatment plans of 121 patients with SLE flare were retrospectively analyzed. Ninety-eight SLE outpatients with sustained remission during the same period were selected as controls. Logistic multivariate regression analysis was employed to screen for risk factors for SLE flare. Results: Infection, thrombocytopenia, arthritis, anti-nucleosome antibodies positive, anti-β2-glycoprotein I (IgG) antibodies positive, and patient's self-discontinuation of medicine maintenance therapy might be risk factors for SLE flare. Patients who discontinued medicine maintenance therapy by themselves had a significantly higher rate of severe SLE flare than patients with regular medicine maintenance therapy ( P = 0.033). The incidence of anemia associated with SLE ( P = 0.001), serositis ( P = 0.005), and pulmonary hypertension ( P = 0.003) in patients who discontinued medicine maintenance therapy were significantly higher than patients with regular medicine maintenance therapy. SLE patients with regular medicine maintenance therapy for less than 3years had a higher risk of pulmonary hypertension than those with regular medicine maintenance therapy longer than 3years ( P = 0.034). Conclusions: The accompanying thrombocytopenia, arthritis, anti-nucleosome antibodies positive and anti-β2-glycoprotein I (IgG) antibodies positive at the onset of SLE may affect the prognosis of SLE. Patient's self-discontinuation of medicine maintenance therapy is the main cause of SLE flare, which may induce severe flare in SLE patients and lead to a significantly higher incidence of pulmonary hypertension.

Proliferation and Apoptosis of B-Cell Lymphoma Cells under Targeted Regulation of FOXO3 by miR-155.

This study aimed to explore B-cell lymphoma cells' proliferation and apoptosis under targeted regulation of FOXO3 by miR-155. We analyzed the differences between B-cell lymphoma cells and B lymphocytes in expressions of miR-155 and FOXO3, explored the effects of miR-155 on proliferation and apoptosis of B-cell lymphoma cells, and relevant mechanisms, and also analyzed the relationship between expressions of miR-155 and FOXO3 in 42 patients with diffuse large B-cell lymphoma (DLBCL) and clinical characteristics of them. B-cell lymphoma cells showed a higher expression of miR-155 and a low expression of FOXO3 than B lymphocytes (both P<0.05). B-cell lymphoma cells transfected with miR-155-inhibitor showed significantly decreased expression of miR-155, significantly weakened cell proliferation ability, and increased cell apoptosis rate (all P<0.05), and they also showed upregulated expression of FOXO3 (P<0.05). Dual-luciferase reporter assay revealed that there were targeted binding sites between miR-155 and FOXO3. Compared with B-cell lymphoma cells transfected with miR-155-inhibitor alone, those with co-transfection showed lower expression of FOXO3, higher proliferation and lower cell apoptosis rate (all P<0.05). The expression of miR-155 in DLBCL tissues was higher than that in tumor-adjacent tissues (P<0.05), and the expressions of miR-155 and FOXO3 were closely related to the international prognostic index (IPI) and the 5-year prognosis and survival of the patients (P<0.05). miR-155 can promote the proliferation of B-cell lymphoma cells and suppress apoptosis of them by targeted inhibition of FOCXO3, and both over-expression of miR-155 and low expression of FOXO3 are related to poor prognosis of DLBCL patients.

[Genotype Analysis of Pregnant Women with α- and ß- Thalassemia in Fuzhou Area of Fujian Province in China].

OBJECTIVE: To analyze the genotype of pregnant women with α- and ß- thalassemia in Fuzhou area of Fujian province in China. METHODS: Blood routine examination and hemoglobin electrophoresis were performed for pregnant women, and positive samples were examined by gap polymerase chain reaction and reverse dot blot hybridization. RESULTS: 412 cases were diagnosed as α-thalassemia (63.9%); 201 cases were diagnosed as ß-thalassemia (31.2%); 32 cases were diagnosed as α and ß-composite thalassemia. There were 12 genotypes in α-thalassemia, whose major genotypes were --SEA/αα, α3.7/αα, -α4.2/αα and αQSα/αα, with carrying rate of 64.32%, 20.14%, 7.77% and 1.94%, respectively. There were 10 genotypes in ß- thalassemia, whose major genotypes were CD41-42/N, CD17/N, IVS-II-654/N and -28/N, with carrying rate of 30.84%, 27.86%, 15.92% and 10.45%, respectively. There were 9 genotypes in α and ß-composite thalassemia, whose major genotypes were --SEA/αα composited CD41-42/N, -α3.7/αα composited CD41-42/N, --SEA/αα composited CD17/N, with carrying rate of 18.75%, 15.62%, 15.62% respectively. CONCLUSION: The major genotypes of pregnant women with α- and ß- thalassemia in Fuzhou area of Fujian province in China are --SEA/αα, α3.7/αα, CD41-42/N and CD17/N. Thalassemia screening and prenatal gene diagnosis should be strengthened in Fuzhou area of Fujian province in China.

Vitamin D receptor gene polymorphism is associated with multiple myeloma.

OBJECTIVES: The aim of this study was to explore the Vitamin D receptor (VDR) gene polymorphism and its association with multiple myeloma (MM) development. METHODS: The peripheral blood of 40 MM cases and 84 healthy controls were collected. Polymerase chain reaction (PCR) and DNA sequencing were applied to detect VDR gene polymorphism (including: FokI, BsmI, ApaI, and TaqI). SHESIS biological information software was used to analyze genotypes, alleles, linkage disequilibrium (LD), haplotype distribution, and their association with MM. RESULTS: Compared with controls, the MM group had a significantly higher frequency of the A allele in BsmI site (8.7% vs 2.4%) and C allele in the TaqI site (10.5% vs 3.6%). These two alleles were closely associated with an increased risk of MM (P = .025; P = .030). The highly rare genotypes (BsmI-AA and TaqI-CC) were found in one patient with MM. CONCLUSION: VDR gene polymorphisms may be a molecular marker of MM risk.

Effect of taurine on immune function in mice with T-cell lymphoma during chemotherapy.

OBJECTIVE: To observe the effect of taurine on immune function in mice with T-cell lymphoma during chemotherapy. METHODS: A total of 40 C57BL/6 mice were selected and randomly divided into 4 groups, namely model group, chemotherapy group, taurine group and chemotherapy + taurine group, each containing 10 mice. Hypodermic injection was adopted to inoculate EL-4 cells in order to establish model of T-cell lymphoma. When the tumor achieved the size of 1 cm3, intervention treatments were given to the groups respectively. Mice in model group received 0.2 mL of normal saline which was intraperitoneally injected on Days 1, 8 and 15 with 3 weeks as a cycle; mice in chemotherapy group were administered with 80 mg/kg body weight of gemcitabine which was also intraperitoneally injected on Days 1, 8 and 15 with 3 weeks as a cycle; mice in taurine group were administered with 80 mg/kg body weight of taurine intraperitoneally injected daily for consecutive 8 d; mice in chemotherapy + taurine group were treated in the same manner as the mice in taurine group and chemotherapy group. Five mice were sacrificed at 2 and 3 weeks after intervention respectively, and the tumor tissues were collected and weighted after removal of auxiliary tissue, then the tumor inhibition rate was calculated. The thymus and spleen of mice sacrificed at 3 weeks after intervention were collected and weighted, and thymus and spleen indexes were calculated. Enzyme linked immunosorbent assay was used to detect the serum levels of IL-4, IL-10, IL-12 and IFN-γ in mice of each group. RESULTS: The tumor weights in chemotherapy group, taurine group and chemotherapy + taurine group after 2 and 3 weeks of treatment were significantly lower than that in model group (P < 0.05); the tumor weight in chemotherapy + taurine group after 2 and 3 weeks of treatment was significantly lower than that in chemotherapy group (P < 0.05); the tumor inhibition rate in chemotherapy + taurine group was significantly higher than that in chemotherapy group and taurine group (P < 0.05); the thymus and spleen indexes in taurine group and chemotherapy + taurine group were significantly higher than those in chemotherapy group and model group (P < 0.05); the thymus and spleen indexes in chemotherapy group were significantly lower than those in model group (P < 0.05); after 3 weeks of treatment, the serum levels of IL-4, IL-12 and IFN-γ in chemotherapy group, taurine group and chemotherapy + taurine group were significantly lower than those in model group (P < 0.05); the IL-4 level in taurine group and chemotherapy + taurine group was significantly lower than that in chemotherapy group (P < 0.05); the serum level of IL-10 in chemotherapy group and chemotherapy + taurine group was significantly higher than that in model group and taurine group (P < 0.05); the serum level of IFN-γ in taurine group and chemotherapy + taurine group was significantly lower than that in model group and chemotherapy group (P < 0.05); after treatment of 3 weeks, the serum levels of IL-4 and IL-10 in chemotherapy group, taurine group and chemotherapy + taurine group were significantly lower than those in model group (P < 0.05), and IL-12 level was significantly higher than that in model group (P < 0.05); the level of IFN-γ in taurine group and chemotherapy + taurine group was significantly higher than that in model group (P < 0.05), while the level of IFN-γ in chemotherapy group was significantly lower than that in the other 3 groups (P < 0.05). CONCLUSIONS: Taurine can effectively enhance the immune function of mice with T-cell lymphoma during chemotherapy, reduce the toxicity of chemotherapy.

In vitro inhibitory effects of dihydromyricetin on human liver cytochrome P450 enzymes.

CONTEXT: Dihydromyricetin (DHM) is the most abundant and active flavonoid component isolated from Ampelopsis grossedentata (Hand-Mazz) W.T. Wang (Vitaceae) and it possesses numerous pharmacological activities. However, whether DHM affects the activity of human liver cytochrome P450 (CYP) enzymes remains unclear. MATERIALS AND METHODS: The inhibitory effects of DHM on eight human liver CYP isoforms (i.e., 1A2, 3A4, 2A6, 2E1, 2D6, 2C9, 2C19 and 2C8) were investigated in vitro using human liver microsomes (HLMs). RESULTS: The results showed that DHM could inhibit the activity of CYP3A4, CYP2E1 and CYP2D6, with IC50 values of 14.75, 25.74 and 22.69 µM, respectively, but that other CYP isoforms were not affected. Enzyme kinetic studies showed that DHM was not only a non-competitive inhibitor of CYP3A4 but also a competitive inhibitor of CYP2E1 and CYP2D6, with Ki values of 6.06, 9.24 and 10.52 µM, respectively. In addition, DHM is a time-dependent inhibitor for CYP3A4 with KI/Kinact value of 12.17/0.057 min-1 µM-1. DISCUSSION AND CONCLUSION: The in vitro studies of DHM with CYP isoforms indicate that DHM has the potential to cause pharmacokinetic drug interactions with other co-administered drugs metabolized by CYP3A4, CYP2E1 and CYP2D6. Further clinical studies are needed to evaluate the significance of this interaction.

Inhibitory Effects of Triptolide on Human Liver Cytochrome P450 Enzymes and P-Glycoprotein.

BACKGROUND AND OBJECTIVES: Triptolide is an active component derived from Tripterygium wilfordii and it possesses numerous pharmacological activities. However, it remains unclear how triptolide influences the activity of human liver cytochrome P450 (CYP) enzymes and P-glycoprotein (P-gp). METHODS: In this study, the inhibitory effects of triptolide on the eight human liver CYP isoforms (i.e., 1A2, 3A4, 2A6, 2E1, 2D6, 2C9, 2C19, and 2C8) were investigated in vitro using human liver microsomes (HLMs), and the effects of triptolide on the activity of P-gp were investigated using a rhodamine-123 uptake assay. RESULTS: The results showed that triptolide inhibited the activity of CYP1A2 and CYP3A4, with 50 % inhibitory concentration (IC50) values of 14.18 and 8.36 µM, respectively, but that other CYP isoforms were not affected. Enzyme kinetic studies showed that triptolide was not only a non-competitive inhibitor of CYP1A2, but also a competitive inhibitor of CYP3A4, with inhibition constant (K i) values of 7.32 and 5.67 µM, respectively. In addition, triptolide is a time-dependent inhibitor for CYP1A2, and the concentration at 50 % maximum inactivation (K I) and maximum inactivation (K inact) values were 286.5 µM and 0.024 min-1, respectively. The rhodamine-123 uptake assay showed that triptolide could not affect the activity of P-gp. CONCLUSIONS: The in vitro studies of triptolide with CYP isoforms and P-gp indicate that triptolide has the potential to cause pharmacokinetic drug interactions with other co-administered drugs metabolized by CYP1A2 and CYP3A4. Further clinical studies are needed to evaluate the significance of this interaction.

[Expression and Prognostic Significance of H3K27 Trimethylation Protein in DLBCL].

OBJECTIVE: To investigate the expression and prognostic effect of H3K27 trimethylation protein (H3K27me3) in diffuse large B-cell lymphoma(DLBCL). METHODS: A total of 102 DLBCL patients from Fujian Provincial Cancer Hospital were enrolled in this study. No therapy had been given before specimen collection. Tissue microarray(TMA) technique and immunohistochemistry(IHC) method were used for H3K27me3 immunostaining. Clinicopathologic and suvival data were carefully collected. The association between tested markers, clinicopathologic characteristics and prognosis were evaluated. Survival rates were analyzed by the Kaplan-Meier method, and prognostic factor were analyzed by the Cox proportional hazards model, the relation of different expression levels with clinical feature and prognosis of patients was compared. RESULTS: The quality of TMA was perfect and meet the standard of analysis. Among all DLBCL patients, 59.8% were characterized with high expression of H3K27me3, correlated with age, ECOG≥2, extranodular disease number≥2, elevation of LDH, medium-high risk IPI. Patients with high H3K27me3 expression manifested that the complete remission rate(CR) and overall remission rate (OR) were lower than those of patients with low expression, i.e., 20% vs 57.5% and 41.8% vs 90%, respectively (P<0.001). In addition, patients with high H3K27me3 expression showed shorter median survival time, i.e., 21.5 mon (P<0.0001). Multivariate analysis indicated that H3K27me3 was an independent risk factor for DLBCL patients (P=0.007). CONCLUSION: TMA technique is valid for the construction of DLBCL tissue chips. Patients with high expression of H3K27me3 indicates little response to treatment, worse outcome and shorter overall survival. The detection of H3K27me3 expression possesses a certain clinical value for prediction of DLBCL outcome.

[Over-expression of DLL4/Notch1 ligand inhibits proliferation of K562 cells].

This study was aimed to explore the effect of DLL4/Notch1 ligand on cell growth in leukemia cell line K562 and its relevant mechanism. The pBudCE4.1-DLL4 plasmid was transfected into K562 cells by lipofectamine 2 000, RT-PCR and Western blot were applied to monitor the mRNA and the protein expression of exogenous DLL4 gene, as well as the expression of Notch1-ICD and target gene Hes1. Expression levels of Rb, YY1 and C-MYC protein in K562 cells were also detected by Western blot. Cell counting Kit-8 was used to detect the proliferation of K562 cells, and flow cytometry with Annexin V staining was used to detect the cell apoptosis. The results showed that the mRNA and protein expression levels of DLL4, Notch1-ICD and Hes1 in cells of experimental group were significantly higher than those of control groups (P < 0.05), indicating the successful activation of the Notch1 signaling pathway. The protein expression levels of Rb, YY1 and C-MYC in cells of experimental group significantly increased when compared with that of control group cells (P < 0.05). After transfection, the proliferation of K562 cells was obviously inhibited, and apoptosis rate in DLL4-transfected cells was significantly enhanced. DLL4 transfection significantly increased the number of cells in G1 phase and decreased that in S phase. It is concluded that the over-expression of DLL4 ligand gene in K562 cells results in successful activation of the Notch1 signaling pathway, increases expression of Rb, YY1 and C-MYC genes, which induces apoptosis and reduces proliferation.

[Effects of DLL4 gene on YY1 and c-Myc protein expression and cell proliferation in leukemia cell line K562].

This study was aimed to explore the effects of Notch ligand DLL4 on the protein expression of the transcription factor YY1 and proto-oncogene c-Myc, as well as K562 cell proliferation. The experiment was divided into 3 groups: normal control, negative control (pBudCE4.1-transfected) and experimental (pBudCE4.1-DLL4-transfected) groups. At 48 hours after transfection, the expression level of DLL4, YY1 and c-Myc proteins in K562 cells of each group were detected by Western blot and indirect immunocytochemical method; the CCK-8 method was used to detect proliferation of K562 cells; at 48 hours after transfection, cell cycle distribution and apoptosis of K562 cells were detected by flow cytometry. The results showed that the protein expression of DLL4, YY1 and c-Myc in K562 cells of every group were found. The protein expression levels of DLL4, YY1 and c-Myc in the experimental group cells were significantly higher than that in control groups (p < 0.05). The cell number in G(0)/G(1) phase increased in the experimental group and was higher than that in the control groups (p < 0.001), and the number of apoptotic cells were also increased (p < 0.001). It is concluded that DLL4 gene was successfully transfected into K562 cells, which increased the protein expression levels of transcription factor YY1 and proto-oncogene c-Myc, leading to the cell proliferation slower in experiment group, inducing the cell cycle arrested in G(0)/G(1) phase and increasing apoptosis.

[Arresting effect of p16 and dll4 transfection on cell cycle of K562 cells].

This study was purposed to investigate the expression and role of eukaryotic expression vector containing p16, dll4 genes in leukemia K562 cells. A vector pBudCE4.1-16-dll4 containing wild type p16cDNA and dll4cDNA was designed and constructed, then this vector was transfected into leukemia K562 cells by using lipofectamine 2000. The expression of p16 and dll4 genes was detected by Western blot, the cell growth curve and cell cycle were determined by CCK-8 kit and flow cytometry respectively. The results showed that the recombinant plasmid pBudCE4.1-16-dll4 was constructed and transfected into K562 cells in vitro successfully. The expression of exogenous P16 and Dll4 proteins could be detected in K562 cells. After transfection for 48 hours, the K562 cells were arrested in G(1) phase, the cell count increased in G(0)/G(1) phase and reduced in S phase, the cell proliferation decreased as compared with control. It is concluded that the p16 and dll4 genes can simultaneously express in K562 cells transfected with recombinant plasmid pBudCE4.1-16-dll4 in vitro which results in G(0)/G(1) arrest and reduces cell proliferation.

[Inhibitory effect of p16, p53 transfection on leukemic cell lines K562 and HL-60].

This study was purposed to construct a vector containing human suppressor gene p53 and p16, and to investigate their expression and effect on K562 and HL-60 cells. pBudCE4.1-53-16 is a vector designed for simultaneous expression of human suppressor gene p53 and p16 in mammalian cell line. After transfection into K562 cells with lipofectamine(TM) 2000, the expression of p53 and p16 genes was detected by Western blot and immunocytochemical method. The growth curve, apoptosis, cell cycle were assayed by CCK-8 and flow cytometry. The results showed that the recombinant plasmid pBudCE4.1-53-16 was constructed successfully and were verified by PCR and restriction analysis. The expression of P53 and P16 protein could be detected after transfection into leukemia cells (K562 and HL-60) for 48 hours. As compared with control group, the cell proliferation in experimental group was inhibited, the cells were arrested in G0 phase and apoptotic cells increased (p<0.001). It is concluded that the recombinant plasmid pBudCE4.1-53-16 has been established. p16 and p53 in the recombinant plasmid pBudCE4.1-53-16 synchronously express in leukemic cells after transfection in vitro for 2 days and results in reduced proliferation, G0 arrest and apoptosis increase.

Cell-specific expression of the diphtheria toxin A-chain coding sequence induces cancer cell suicide.

OBJECTIVE: To test whether the diphtheria toxin A (DT-A) chain coding sequence linked to murine immunoglobulin Kappa light chain (IgKappa) promoter and enhancer have selective cytocidal effects on IgKappa producing cells. METHODS: The diphtheria toxin A gene or beta galactosidase (beta-gal) gene were linked to a murine IgKappa promoter and enhancer to construct pcDNA3IgKappaDTA or pcDNA3IgKappaLacZ plasmids. These plasmids were transfected into IgKappa producing or non-producing cells by the liposome coated DNA method. Expression of beta-gal activity and effects on cell growth of transfected cells were assessed. RESULTS: The beta-gal gene, under the control of cytomegalovirus (CMV) promoter, can express in all cell lines. Expression of beta-gal under the control of the IgKappa promoter was detected only in the IgKappa producing cell line, CA46. Expression of beta-gal was greatly suppressed when cotransfected with pcDNA3IgKappaDTA in CA46 cells. Cell growth of CA46 cells transfected with pcDNA3IgKappaDTA plasmid was significantly inhibited compared with CA46 cells transfected with pcDNA3IgKappaLacZ. CONCLUSION: Selective killing of IgKappa producing cells can be attained by introducing the diphtheria toxin A gene under the control of IgKappa promoter and enhancer.

Co-transfection of p16(INK4a) and p53 genes into the K562 cell line inhibits cell proliferation.

BACKGROUND AND OBJECTIVES: The tumor suppressor genes p53 and p16(INK4a), both of which act in tumor surveillance, are homozygously deleted in the human leukemia cell line K562. This study was performed to assess whether co-transfection of the p16(INK4a) and p53 genes could inhibit K562 cell proliferation. DESIGN AND METHODS: p16(INK4a) and p53 genes were co-transfected into K562 cells with liposome, and the expression of the transfected genes was detected by Western-immunoblotting and immunocytochemistry. The effect of the p16(INK4a) and p53 transfected cell culture was quantified by trypan blue staining, and the number of recovered viable cells was assessed every day after transfection. Cells were analyzed for expression of annexin V in order to detect apoptosis. Differentiation of transfected K562 cells was measured by the benzidine oxidation test, and the cell cycle was analyzed by flow cytometry. RESULTS: After co-transfection, there were 23% and 28% p53 and p16(INK4a) positive cells respectively. Co-transfection with p16(INK4a) and p53 genes significantly inhibited cell proliferation when compared to transfection with either p16(INK4a) or p53 gene. The percentage of cells expressing the apoptosis-related cell surface antigen annexin V was significantly higher in p53 and p16(INK4a) transfected cells than in p53 or p16(INK4a) transfected cells (6.24+/-0.37% vs 4.88+/- 0.17%, p<0.05 and vs 2.78+/-0.26%, p<0.05, respectively). p16(INK4a) and p53 co-transfection significantly increased the number of cells in G1 phase and decreased that in S phase. INTERPRETATION AND CONCLUSIONS: Expression of wild-type p16(INK4a) and p53 genes in K562 cells results in reduced proliferation and apoptosis. Introduction of exogenous p16(INK4a) and p53 genes into K562 cells might contribute to the clinical treatment of leukemia.

[Inhibition of K562 cell proliferation by wild type p16 and p53 genes co-transfection].

The tumor suppressor gene p53 and p16, both of which play an important role in inhibition of tumorigenesis, are homozygously deleted in human myeloid leukemia cell line K562. To explore the inhibition of K562 cell proliferation by wild type p16 and p53 genes, both p16 and p53 genes were co-transfected into K562 cells mediated by liposome. The expression of the two genes was measured by immunocytochemical method, the cell cycle was analysed by flow cytometry, and the number of recovered viable cells was assessed after transfection. After co-transfection, the p53 and p16 positive cells were 23% and 28%, respectively. The results showed that co-transfection of p16 and p53 genes significantly inhibits cell proliferation comparing with transfection either by p16 gene or by p53 gene (P < 0.05). Expression of p16 and p53 proteins increased the cell number in G(1) phase but decreased the cell number in S phase. It is concluded that co-transfection of p16 and p53 genes has a stronger growth-inhibitory effect on K562 cell growth than that of transfection only by p16 gene or by p53 gene, may be a pathway for gene therapy in leukemia.