[Effect of up-regulated expression of tumor suppressor gene p14(ARF) on apoptosis of chronic myeloid leukemia cells].

Objective: To investigate the effect of up-regulated expression of tumor suppressor gene p14(ARF) on apoptosis of chronic myeloid leukemia (CML) cells and its interaction with imatinib.

Methods: Tumor suppressor gene p14(ARF) was transduced into K562 (K562-p14(ARF)) and 4 blast crisis primary CML cells (CML-BC 1-4) using vesicular stomatitis virus glycoprotein (VSV-G) pseudotyped lentiviral vector with cells transduced by empty vector as control. Fluorescence microscopy and flow cytometry were applied to measure transduction efficiency, and Western blotting assay was used to detect p14(ARF) protein of K562 cells.

[Influence of gene transduction mediated by lentivirus vector on gene expression of human CD34+ cord blood cells].

Objective: To investigate the influence of gene transduction mediated by lentivirus vector on human CD34+ cord blood cell (CBCs) gene expression.

Methods: CD34+ cells were isolated and transduced with the third-generation self-inactivating ( SIN) lentiviral vector carrying green fluorescent protein (GFP). The total RNA from transduced cells was extracted and the differences of genotypes between the transduced and non-transduced CD34+ cells were determined with cDNA microarray analysis.

[Reversal of mdrl gene-dependent multidrug resistance in multidrug resistance human leukemia cell line K562/ADM using short hairpin RNA expression vectors].

Objective: To explore the role of reversal multidrug resistance (MDR) using short hairpin RNA (shRNA) expression vectors in multidrug resistance human leukemia cell line K562/ADM.

Methods: The oligonucleotides with 19-mer hairpin structure were synthesized. The shRNA expression vectors were constructed and introduced into K562/ADM cells.

[Study of apoptosis gene expression in U937 cells induced by adhesion culture with mesenchymal stem cell].

Objective: To compare apoptosis gene expression profiling of U937 cells in suspension culture with that cultivated with mesenchymal stem cells (MSCs), and find out the relationship between drug resistance of leukemia cells and hemopoietic microenvironment.

Methods: U937 cells were cultivated in adhesion culture with MSCs and in suspension culture for 48 hours. Cell cycle was determined by flow cytometry and gene expression profiling by cDNA microarray.

Study on the bone marrow mesenchymal stem cells induced drug resistance in the U937 cells and its mechanism.

Background: The hematopoietic microenvironment (HM) plays a critical role in malignant cell growth, patient survival, and response to chemotherapy in hematologic malignancies. However, mechanisms associated with this environmental influence remain unclear. In this study, we investigated the role of bone marrow derived mesenchymal stem cells (MSCs) in U937 cell line, to find out the relations between leukemia drug resistance and the MSCs.