ABSTRACT
T cell acute lymphoblastic leukemia (T-ALL), an aggressive and heterogeneous malignancy originating from T cell precursors (thymocytes), accounts for ~15% of all ALL cases in children and for ~25% in adults. The present study aimed to investigate the role of microRNA-221 (miR-221) in the regulation of cell viability and apoptosis of human T-ALL cells and its related regulatory mechanisms. To perform this investigation, miR-221 was upregulated or knocked down in human T-ALL cells (Jurkat cells) using miR-221 mimic or inhibitor, respectively. Then, cell viability was determined using a 3-(4,5-dimethylthiahiazol-2-y1)-2,5-diphenytetrazolium bromide assay, cell invasion and migration were analyzed via Transwell assays, and cell apoptosis was detected using flow cytometry. It was found that transfection with a miR-221 inhibitor significantly inhibited Jurkat cell viability, migration and invasion, and induced Jurkat cell apoptosis. Whereas, transfection with the miR-221 mimic resulted in the opposite effects. Besides, the results showed that phosphatase and tensin homologue deleted on chromosome 10 (PTEN) was a target of miR-221. Moreover, it was observed that the effects of the miR-221 inhibitor on Jurkat cell viability, migration and invasion, and cell apoptosis were significantly eliminated by PTEN-small interfering RNA. In addition, it was shown that the phosphatidylinositol 3-kinase/AKT pathway was involved in the effect of miR-221 on Jurkat cells. In conclusion, the data indicated that miR-221 existed as an oncogene in T-ALL, and its downregulation could inhibit the development of ALL by targeting PTEN. Therefore, miR-221 may be a novel potential therapeutic target for ALL.
ABSTRACT
FLT3-ITD+ acute myeloid leukemia (AML) is an important subtype of AML, accounting for approximately 25 % of all AML cases in the world. Recently, increasing evidence has shown that circular RNAs (circRNAs) can act as effective biomarkers of various human cancers. However, the roles of circRNAs in AML remain largely unclear. In the present study, circ_0000370 was found to be significantly increased in FLT3-ITD+ AML and was demonstrated to act as an oncogenic circRNA of AML in vitro. TargetScan results showed that miR-1299, miR-370-3p, miR-502-5p, miR-1281 and miR-640 were potential targets of circ_0000370, and miR-1299 had the broadest range of interactome compared with other microRNAs of interest. Moreover, we demonstrated that S100A7A was a target gene of miR-1299, and circ_0000370 could regulate S100A7A expression by sponging miR-1299 in AML cell lines. Therefore, we suggest that the promoting effects of circ_0000370 on the progression of FLT3-ITD+ AML might be relevant to the inhibition of miR-1299 and the upregulation of S100A7A.
Subject(s)
Leukemia, Myeloid, Acute/metabolism , MicroRNAs/metabolism , RNA, Circular/genetics , RNA, Circular/metabolism , S100 Calcium Binding Protein A7/metabolism , Apoptosis , Cell Cycle , Cell Line, Tumor , Cell Survival , Gene Expression Regulation, Leukemic , Humans , MicroRNAs/genetics , Proto-Oncogene Protein c-fli-1 , RNA/genetics , RNA/metabolism , fms-Like Tyrosine Kinase 3ABSTRACT
SZ117 is a monoclonal antibody against matrix metalloproteinase-2 (MMP-2) and exhibits anti-tumor angiogenic effect. In this study, we observed that SZ117 bound to a 280 kDa protein, which was detected in tumor cell-derived Matrigel and various tumor cells. Using immunoprecipitation, mass spectrometry analysis, and Western blot analysis, we identified the 280 kDa protein as filamin A and found that filamin A and its degraded products, notably a 53 kDa fragment, were released from a variety of tumor cells. This suggests that SZ117 is useful in the study of the pathogenesis of filamin A and that blockage of filamin A by SZ117 might contribute to the anti-tumor angiogenic effect of the monoclonal antibody.
Subject(s)
Antibodies, Monoclonal/immunology , Contractile Proteins/immunology , Microfilament Proteins/immunology , Peptide Fragments/immunology , Amino Acid Sequence , Contractile Proteins/chemistry , Contractile Proteins/metabolism , Filamins , Humans , Microfilament Proteins/chemistry , Microfilament Proteins/metabolism , Molecular Sequence Data , Molecular Weight , Peptide Fragments/chemistry , Peptide Fragments/metabolism , Tumor Cells, CulturedABSTRACT
In this study, using an in vitro tube formation model, we observed that SZ117, a monoclonal antibody against matrix metalloproteinase-2 (MMP2), attenuated a capillary-like tube structure formed by tumor endothelial cell 3B11 and human sarcoma cell MG63. In addition, gelatin zymography showed that SZ117 markedly inhibited MMP2 activity, but did not affect the capability of MMP9-mediated gelatin degradation. These data suggest that SZ117 might have an anti-tumor angiogenic effect and that angiogenic tumor cells and MMP2 may be targeted by monoclonal antibodies for novel anti-tumor angiogenic and anti-cancerous drug discovery.
