Small hairpin RNA targeting at Bcl-2 increases cytarabine-induced apoptosis in Raji cells

Nanoparticle-based strategy for personalized B-cell lymphoma therapy

B-cell lymphoma is associated with incomplete response to treatment, and the development of effective strategies targeting this disease remains challenging. A new personalized B-cell lymphoma therapy, based on a site-specific receptor-mediated drug delivery system, was developed in this study. Specifically, natural silica-based nanoparticles (diatomite) were modified to actively target the antiapoptotic factor B-cell lymphoma/leukemia 2 (Bcl2) with small interfering RNA (siRNA). An idiotype-specific peptide (Id-peptide) specifically recognized by the hypervariable region of surface immunoglobulin B-cell receptor was exploited as a homing device to ensure specific targeting of lymphoma cells. Specific nanoparticle uptake, driven by the Id-peptide, was evaluated by flow cytometry and confocal microscopy and was increased by approximately threefold in target cells compared with nonspecific myeloma cells and when a random control peptide was used instead of Id-peptide. The specific internalization efficiency was increased by fourfold when siRNA was also added to the modified nanoparticles. The modified diatomite particles were not cytotoxic and their effectiveness in downregulation of gene expression was explored using siRNA targeting Bcl2 and evaluated by quantitative real-time polymerase chain reaction and Western blot analyses. The resulting gene silencing observed is of significant biological importance and opens new possibilities for the personalized treatment of lymphomas.

Combination of BCL11A siRNA with vincristine increases the apoptosis of SUDHL6 cells

Background

B cell chronic lymphocytic leukemia/lymphoma 11 A (BCL11A) is associated with human B cell malignancy initiation. Our previous study has shown that downregulation of BCL11A mRNA by small interfering RNA (siRNA) is capable of inducing apoptosis in the SUDHL6 cell line. To further explore the effects of BCL11A siRNA on the enhanced cytotoxicity of a chemotherapeutic drug, we investigated the effects of BCL11A siRNA combined with vincristine (VCR) on SUDHL6 cell proliferation and apoptosis.

Methods

Chemically synthesized BCL11A siRNA was transfected into SUDHL6 cells using the HiPerFect Transfection Reagent in combination with VCR. Cell proliferation was measured by the CCK8 assay. The morphology of apoptotic cells was observed with Hoechst 33258 staining. The rate of cell apoptosis was determined by annexin V-fluorescein isothiocyanate/propidium iodide double staining using fluorescence-activated cell sorting (FACS) analysis.

Results

After BCL11A siRNA plus VCR treatment, cell proliferation was significantly decreased in comparison with VCR or BCL11A siRNA treatment alone and negative control siRNA plus VCR treatment (P <0.05). The apoptotic rate of BCL11A siRNA plus VCR treated cells was significantly increased compared with BCL11A siRNA and VCR treatment alone and negative control siRNA plus VCR treatment (P <0.05).

Conclusions

The combination of BCL11A siRNA and VCR increases apoptosis in SUDHL6 cells. Our study implies that BCL11A siRNA in combination with VCR may be a useful approach for improving effective treatment for B cell lymphoma.

Cytotoxic effect of icaritin and its mechanisms in inducing apoptosis in human burkitt lymphoma cell line

Icaritin (ICT), a hydrolytic product of icariin from Epimedium genus, exhibits antitumor activities in several human solid-tumor and myeloid leukemia cells with extensive influence on various cell signal molecules, such as MAPKs being involved in cell proliferation and Bcl-2 participating in cell apoptosis. However, the effect of icaritin on Burkitt Lymphoma has not been elucidated. In the present study, we first screened the potential effect of icaritin on Burkitt lymphoma Raji and P3HR-1 cell lines and found that icaritin showed cytotoxicity in both cell lines. We further found that icaritin could significantly inhibit Raji cells proliferation with S-phase arrest of cell cycle and induced cell apoptosis accompanied by activation of caspase-8 and caspase-9 and cleavage of PARP. We also observed that icaritin was able to decrease Bcl-2 levels, thus shifting the Bcl-2/Bax ratio, and it could obviously reduce c-Myc, a specific molecular target in Burkitt lymphoma. Our findings demonstrated that icaritin showed cytotoxicity, inhibited cell growth, caused S arrest, and induced apoptosis in Burkitt lymphoma cells and provided a rationale for the further evaluation of icaritin for Burkitt lymphoma therapy.

Combined transfection of Bcl-2 siRNA and miR-15a oligonucleotides enhanced methotrexate-induced apoptosis in Raji cells

Objective

B-cell lymphoma 2 (Bcl-2) is an important member of the Bcl-2 family of proteins that regulate the induction of apoptosis. This study aims to investigate whether Bcl-2 small interfering RNA (siRNA) combined with miR-15a oligonucleotides (ODN) could enhance methotrexate (MTX)-induced apoptosis in Raji cells.

Methods

Chemically synthesized miR-15a ODN and Bcl-2 siRNA were transfected in Raji cells by using a HiPerFect Transfection Reagent and then combined with MTX. Expression levels of Bcl-2 protein were detected by Western blot. Cell proliferation was determined by CCK8 assay. The rate of cell apoptosis was determined by Annexin V/PI double staining. The morphology of apoptotic cells was observed by Hoechst-33 258 staining.

Results

After the cells were transfected with miR-15a ODN combined with Bcl-2 siRNA, Bcl-2 protein levels were evidently decreased. CCK8 assay showed that cell proliferation was significantly decreased and was significantly lower in miR-15a ODN combined with Bcl-2 siRNA plus MTX group than in miR-15a ODN with methotrexate group, Bcl-2 siRNA with MTX group, and single MTX group (P<0.05). Hoechst 33258 staining revealed numerous apoptotic cells. AnnexinV/PI double staining showed that the apoptotic rates were (13.13±1.60)%, (34.47±2.96)%, (32.87±3.48)%, and (45.47±2.16)% in MTX, Bcl-2 siRNA plus MTX, miR-15a ODN plus MTX, and miR-15a ODN combined with Bcl-2 siRNA plus MTX groups, respectively. Among these groups, the apoptotic rate of miR-15a ODN combined with Bcl-2 siRNA plus MTX group was the highest; this apoptotic rate was also significantly different from that of miR-15a ODN or Bcl-2 siRNA plus MTX (P<0.05).

Conclusions

Bcl-2 siRNA combined with miR-15a ODN could enhance MTX-induced apoptosis in Raji cells. Bcl-2 siRNA and miR-15a combined with MTX may be a useful approach to improve the treatment effects on lymphoma.

The effect of Bcl-2 siRNA combined with miR-15a oligonucleotides on the growth of Raji cells

Bcl-2 is a prominent member of the Bcl-2 family of proteins that regulate the induction of apoptosis. Here, we investigated the effect of Bcl-2 small interfering RNA (siRNA) combined with miR-15a oligonucleotides (ODN) on the growth of Raji cells. The expression levels of Bcl-2 mRNA and protein were detected. The inhibition of cell growth and apoptosis was determined. Atomic force microscopy was utilized to observe the cell-surface ultrastructural changes. After transfection of combination, protein and mRNA levels of Bcl-2 obviously were decreased. The growth of cells was significantly inhibited compared with those cells transfected with Bcl-2 siRNA or miR-15a alone. Apoptotic rate significantly increased. The cells of apoptosis showed a roughness variation on cell membranes. These results suggest that the combination of Bcl-2 siRNA and miR-15a ODN increases apoptosis in Raji cells. Our study implies that the combination of Bcl-2 siRNA and miR-15a may be a useful approach in treatment for lymphoma.

Downregulation of BCL11A by siRNA induces apoptosis in B lymphoma cell lines

The B-cell chronic lymphocytic leukemia (CLL)/lymphoma 11A gene (BCL11A) encodes a krüppel-like zinc finger protein, which is important in thymopoiesis and has been associated with hematopoietic malignancies. In this study, we investigated whether the downregulation of BCL11A mRNA by small interference RNA (siRNA) was capable of inducing apoptosis, and tested the effect of BCL11A siRNA combined with BCL2 siRNA in B lymphoma cell lines (SUDHL6, EB1). BCL11A siRNA was transfected into SUDHL6, EB1 cells with HiPerfect transfection reagents. After transient transfection with BCL11A siRNA, the expression levels of BCL11A mRNA and protein were assayed by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and western blot analysis. The cell proliferation was determined by a cell counting kit-8 (CCK8) assay. Apoptosis was determined by morphological observation and flow cytometric analysis. The results showed that the expression levels of BCL11A mRNA and protein from SUDHL6, EB1 cells transfected with BCL11A siRNA decreased, compared with either the scrambled negative control siRNA group or untransfected cells group (P<0.05). Viability of cells transfected with BCL11A siRNA was less compared to cells transfected with control siRNA and untransfected SUDHL6, EB1 cells, respectively (P<0.05). BCL11A siRNA induced apoptosis in both SUDHL6 and EB1 cells. BCL11A siRNA combined with BCL2 siRNA significantly inhibited cell growth. Apoptotic rates of SUDHL6, EB1 cells treated with BCL11A siRNA combined with BCL2 siRNA significantly increased (P<0.05), compared with either the scrambled control (Sc) siRNA and BCL2 siRNA combination or BCL2 or BCL11A siRNA-treated cells alone. Findings of this study suggest the downregulation of BCL11A mRNA by siRNA was able to induce apoptosis. Moreover, BCL11A siRNA combined with BCL2 siRNA increased apoptosis in SUDHL6, EB1 cells. Thus, suppression of BCL11A expression may be a useful approach in the treatment of B lymphoma.