Silencing HIF-1α reduces the adhesion and secretion functions of acute leukemia hBMSCs

Differential expression of genes associated with hypoxia pathway on bone marrow stem cells in osteoporosis patients with different bone mass index

Background

This study aimed to assess gene expression changes associated with hypoxia pathway on bone marrow stem cells (BMSCs) and explore effects of bone mass index (BMI) on hypoxia pathway of osteoporosis (OP) patients.

Methods

Human BMSCs were isolated from bone marrow. Subjects were divided into healthy control group and OP group which was further divided into BMI <25 OP subgroup and BMI ≥25 OP subgroup.

Results

The genes downregulated in OP patients were involved in hypoxia pathway. Furthermore, those genes were even downregulated in OP patients BMI ≥25 subgroup than OP patients BMI <25 subgroup. The genes were expressed in response to decreased oxygen levels, and their functions are related to photoperiodism, positive regulation of myoblast differentiation, and entrainment of circadian clock by gene ontology (GO) analysis.

Conclusions

The expression of genes associated with hypoxia pathway on BMSCs in OP patients are lower than healthy subjects, and the expression of genes related to carbohydrate metabolism are lower in overweight OP patients than in normal weight OP patients. These results need further research.

Low-dose triptolide in combination with idarubicin induces apoptosis in AML leukemic stem-like KG1a cell line by modulation of the intrinsic and extrinsic factors

Leukemia stem cells (LSCs) are considered to be the main reason for relapse and are also regarded as a major hurdle for the success of acute myeloid leukemia chemotherapy. Thus, new drugs targeting LSCs are urgently needed. Triptolide (TPL) is cytotoxic to LSCs. Low dose of TPL enhances the cytotoxicity of idarubicin (IDA) in LSCs. In this study, the ability of TPL to induce apoptosis in leukemic stem cell (LSC)-like cells derived from acute myeloid leukemia cell line KG1a was investigated. LSC-like cells sorted from KG1a were subjected to cell cycle analysis and different treatments, and then followed by in vitro methyl thiazole tetrazolium bromide cytotoxicity assay. The effects of different drug combinations on cell viability, intracellular reactive-oxygen species (ROS) activity, colony-forming ability and apoptotic status were also examined. Combination index-isobologram analysis indicates a synergistic effect between TPL and IDA, which inhibits the colony-forming ability of LSC-like cells and induces their apoptosis. We further investigated the expression of Nrf2, HIF-1α and their downstream target genes. LSC-like cells treated with both TPL and IDA have increased levels of ROS, decreased expression of Nrf2 and HIF-1α pathways. Our findings indicate that the synergistic cytotoxicity of TPL and IDA in LSCs-like cells may attribute to both induction of ROS and inhibition of the Nrf2 and HIF-1α pathways.