Li-Sheng Wang

Radiation therapy can cause haematopoietic damage, and mesenchymal stem cells (MSCs) derived extracellular vesicles (EVs) have been shown to reverse this damage. Our previous research showed that dental pulp stem cells (DPSCs) have a strong proliferation capacity and can produce abundant amounts of EVs to meet the requirements for use in vitro and in vivo. DPSCs derived EVs (DPSCs-EVs) are evaluated for their effect on reducing haematopoietic damage. Haematopoietic stem cell (HSC) numbers and function were assessed by flow cytometry, peripheral blood cell counts, histology and bone marrow transplantation. Epidermal growth factor (EGF) was used as a reference for evaluating the efficiency of EVs. miRNA microarray was employed to find out the changes of miRNA expression after cells being irradiated in vivo and the role they may play in mitigation the radiation caused injury. We observed the effect of DPSCs-EVs on promoting proliferation and inhibiting apoptosis of human umbilical vein endothelial cells (HUVECs) and FDC-P1 cells in vitro. We found that DPSCs-EVs and EGF could comparably inhibit the decrease in WBC, CFU count and KSL cells in vivo. We also verified that EVs could accelerate the recovery of long-term HSCs. In summary, DPSCs-EVs showed an apoptosis resistant effect on HUVECs and FDC-P1 cells after radiation injury in vitro. EVs from DPSCs were comparable to EGF in their ability to regulate haematopoietic regeneration after radiation injury in vivo. Radiation could alter the expression of some miRNAs in bone marrow cells, and EVs could correct these changes to some extent.

Mesenchymal stem cells (MSC) possess important biological characteristics of tissue repair and regeneration. MSC exert the properties promoting endogenous angiogenesis and have been widely applied in treatment of ischemia diseases. The therapeutic potency of MSC for ischemia diseases is owing to their secretion of angiogenic growth factors and release of exosomes. MSC promote angiogenesis stronger in hypoxia environment, and their miRNA played an important role in mediating regulation. This review summarizes recent advances in treatment of angiogenesis using MSC and their mechanisms. The angiogenic activities of MSC under hypoxia condition and their regulation by a miRNA network were discussed.

To clarify the roles of SPK pathway in the regulation of proliferation, survival and glucose consume of human erythroleukemia TF-1 cells. The interfering in SPK expression of TF-1 cells was performed using leutivirus vector-mediated shRNA, the interference efficacy of SPK in TF-1 cells was detected by RT-qPCR and Western blot, the viability of TF-1 cell proliferation was detected by using CCK-8 method, the apoptosis of TF-1 cells was determined by flow cytmetry with Annexin V staining. Hypoxia up-regulated the expression of HIF-1α, HIF-2α, and SPK in TF-1 cells. SPK treatment resulted in reduced proliferation and induced apoptosis in TF-1 cells. Furthermore, knockdown of the SPK significantly reduced utilization and consumption of glucose. The SPK is key signalling molecule involved in regulation of hypoxia-induced proliferation and glucose metabolism in TF-1 cells, and plays an important rote in proliferation and energy metabolism of leukemia cells.

To construct a recombinant lentiviral expression vectors carrying MEG3 and to evaluate its effects on XG-7 cell apoptosis. A full-length genomic fragment of human MEG3 was cloned from the pcDNA3.0-MEG3 packaging plasmid and was amplified by PCR. New restriction sites were introduced to be blunted with T4 DNA Ligase. The sequence of the amplified segments was sub-cloned into lentivirus expression vector pCDH-EF1-MCS-T2A-copGFP.The recombined lentiviral expression vector was transfected into 293T cells. FACS was used to detect the effect of MEG3 on XG-7 cell apoptosis after being infected by optimized MOI. The recombined lentiviral expression vector pCDH-EF1-MEG3-copGFP was constructed successfully. The results showed that pCDH-EF1-MEG3-copGFP could increase the mRNA expression of MEG3 dramatically, its transfection efficiency was more than 90%. The apoptosis rate in XG-7 cells (26.8±2.8%) was very significantly higher than that of the control group (P<0.01). The recombined lentiviral LncRNA expression vector targeting MEG3, pCDH-EF1-MEG3-copGFP, has been successfully constructed, the pCDH-EF1-MEG3-copGFP can induce the cell apoptosis in human myeloma cell lines. This study set up a basis to further explore the relationship between human myeloma cells and LncRNA-MEG3 gene.

Kinesin spindle protein (KSP) is a microtubule-associated motor protein that is specifically expressed by mitosis cells. It is highly expressed in various types of tumors including hematomalignances and solid tumors. Chemical KSP inhibition has become a novel strategy in the development of anticancer drugs. SB743921 is a selective inhibitor for KSP, which is a mitotic protein essential for cell-cycle progression. Although SB743921 has shown antitumor activities for several types of cancers and entered into clinical trials, its therapeutic effects on breast cancer and mechanisms have not been explored. In this study, we tested the antitumor activity of SB743921 in breast cancer cell lines and partly elucidated its mechanisms. KSP and denticleless E3 ubiquitin–protein ligase homolog (DTL) are overexpressed in breast cancer cells compared with no-cancer tissues. Chemical inhibition of KSP by SB743921 not only reduces proliferation but also induces cell-cycle arrest and leads to apoptosis in breast cancer cells. Treatment of MCF-7 and MDA-MB-231 breast cancer cell lines with SB743921 results in decreased ability of colony formation in culture. SB743921 treatment also causes a KSP accumulation in protein level that is associated with cell arrest. Furthermore, we showed that SB743921 treatment significantly reduces the expression of bcl-2 and cell cycle-related protein DTL, and upregulates p53 and caspase-3 in breast cancer cells. Taken together, these data indicated that SB743921 can be expected to be a novel treatment agent for breast cancers.