BACKGROUND: Raman spectrum, compared with conventional detection technologies, is a rapid, non-invasive and label-free optical method. Its application has become an issue of concern in biomedical research. However, further studies are warranted to optimize the acquisition condition of Raman spectra from different stem cells. OBJECTIVE: To explore the effect of the wavelength of laser and the groove frequency of gratings to obtain the optimized parameter combination for Raman spectrum collection in human stem cells. METHODS: Using human mesenchymal stem cells as samples, the effects of different laser wavelengths (532, 38,785 nm) and different grating groove frequency (600, 1200, 1800 gr/mm) on Raman spectra were compared respectively. Then the different combinations of the wavelength and groove frequency were used and compared in terms of the spectra resolution and acquisition time, and the best acquisition condition was selected and applied in a comparison study on the Raman spectra from human mesenchymal stem cells and human embryonic stem cells. RESULTS AND CONCLUSION: The wavelengths of lasers and groove frequencies of gratings showed compound impacts on both the spikes at different wavenumbers and the ratio between spikes; the combination of 785 nm and 1200 gr/mm was confirmed to be the best spectrum features for human mesenchymal stem cells. The comparison of Raman spectra from human mesenchymal stem cells and human embryonic stem cells implies that the embryonic stem cells contain higher nucleic acids than the mesenchymal stem cells, while the mesenchymal stem cells appear to contain more proteins and lipids.

Objective To investigate the antitumor activity of IL-24 delE5 in human leukemia cell line K562. Methods The expression of mda-7/IL-24 and its splice variant induced by TPA in leukemic cell lines, U937 and HL-60, was evaluated. The effects of IL-24 delE5 in K562 on cell proliferation, colony-forming ability, cell cycle, apoptosis, and tumor growth in vivo by using MTr assay, colony forming assay, flow cytometry, Annexin-V/PI and tumor xenograft models in nude mice were assessed. Meantime, the effects of IL-24 delE-5 and mda-7/IL-2A were compared. Results The expression of IL-24 dciE5 was detected in differentiated U937 and HL-60 cells. Transfection with IL-24 delE5 significantly reduced tumor cell viability, inhibited colony formation. Comparing with the control, G_0/G_1 stage add from (24.46±3.99) % to (42.69±3.04) %, caused cell cycle arrest in G_0/G_1 stage and significantly inhibited the growth of K562 transplantation tumor. No significant differences in the aforementioned antileukemia characteristics between IL-24 delE5 and mda-7/IL-24 was found. Conclusion Similar with mda-7/IL-24, IL-24 delE5 can efficiently inhibit the proliferation of K562 in vitro and in vivo, probably through induction of G_0/G_1 cell cycle arrest.

Objective To explore the mechanism of the cell-cycle arrest induced by human melanoma differentiation associated gene-7 (mda-7/IL-24) in chronic myelocytic leukemia cell line K562. Methods Microarray analysis was performed to determine the genes that were differentially regulated by mda-7/IL-24 in K562 cells, and was validated by realtime PCR. The phosphorylated pRb were detected by Western blotting analysis. Results A microarray analysis showed that G_0/G_1 phase-associated genes p21~(WAF-1) and BCCIP were up-egulated, while cdk6 and Smurf2 were down-regulated. The directional change in the expression of the four genes was successfully validated with real-time quantitative RT-PCR. pRb Set~(795) phosphorylation was observed with no modification of the pRb protein level. Conclusion These results suggest that IL-24/mda-7 may inhibit K562 proliferation and induce G_0/G_1 cell cycle angst by up-regulating p21~(WAF-1) and BCCIP, down-regulating cdk6 and Smurf2.

OBJECTIVETo investigate the potential immunomodulatory properties of fetal bone marrow derived mesenchymal stem cells (FBM- MSCs).

METHODSMononuclear cells from the bone marrow of second trimester (14-22 wks) fetus were isolated and cultured for the derivation of MSCs. The derived FBM-MSC cells were characterized via morphology, immunophenotyping and the adipogenic and osteogenic differentiation assays. The immunomodulatory properties of FBM-MSC on lymphocytes were evaluated through the co- culture assay with PHA activated adult peripheral blood mononuclear cells (PBMCs).

RESULTSDerived FBM-MSCs were CD29⁺, CD44⁺, CD49e⁺, CD73⁺, CD90⁺, CD105⁺ and CD31⁻ , CD34⁻ , CD45⁻ , HLA-DR⁻ and can be differentiated into adipocytes and osteocytes. When co-cultured with PHA-activated PBMCs, FBM-MSCs inhibited the proliferation of lymphocytes up to 96% and down-regulated the secretion of inflammatory cytokines such as IFN-γ and TNF-α up to 90.9% and 58.4% respectively. When compared with FBM-MSCs cultured alone, the expression of MSCs derived immunomodulatory cytokines, such as IDO, TSG-6 and TGF-β, was up-regulated significantly in the co-culture system.

CONCLUSIONMSC derived from fetal bone marrow demonstrated immunosuppressive effects on adult PBMCs in vitro. MSC-derived cytokines like IDO, TSG-6 and TGF-β may be critical for FBM-MSCs mediated immunosuppressive function.

Adult ; Bone Marrow ; Bone Marrow Cells ; cytology ; immunology ; Cell Differentiation ; Cell Proliferation ; Cells, Cultured ; Coculture Techniques ; Cytokines ; Hematopoietic Stem Cells ; Humans ; Immune Tolerance ; Immunophenotyping ; In Vitro Techniques ; Leukocytes, Mononuclear ; Lymphocytes ; Mesenchymal Stromal Cells ; cytology ; immunology ; Osteogenesis