January 19, 2015

Isolation and Characterization of Multipotent and Pluripotent Stem Cells from Human Peripheral Blood

Stem cells are commonly classified based on the developmental stage from which they are isolated, although this has been a source of debate amongst stem cell scientists. A common approach classi- fies stem cells into three different groupings: Embryonic Stem Cells (ESCs), Umbilical Cord Stem Cells (UCBSCs) and Adult Stem Cells (ASCs), which include stem cells from bone marrow (BM), fat tissue (FT), engineered induced pluripotent (IP) and peripheral blood (PB). By definition stem cells are progenitor cells capable of self-renewal and differentiation hypothetically “ab infinitum” into more specialized cells and tissue. The main intent of this study was to determine and charac- terize the different sub-groups of stem cells present within the human PB-SCs that may represent a valid opportunity in the field of clinical regenerative medicine. Stem cells in the isolated mono- nucleated cells were characterized using a multidisciplinary approach that was based on mor- phology, the expression of stem cell markers by flowcytometry and fluorescence analysis, RT-PCR and the capacity to self-renew or proliferate and differentiate into specialized cells. This approach was used to identify the expression of hematopoietic, mesenchymal, embryonic and neural stem cell markers. Both isolated adherent and suspension mononucleated cells were able to maintain their stem cell properties during in-vitro culture by holding their capacity for proliferation and differentiation into osteoblast cells, respectively, when exposed to the appropriate induction me- dium. 

January 19, 2015

New Year Message from Editor

The Roman calendar identified January as the month in which looking back and looking forward were both appropriate. Biomedical Research and Therapy (BMRAT) now has one-­‐‑year history of publication, following a one-­‐‑year period of preparation, and the first volume has been wrapped up. The vital signs of the journal were positive from the beginning and are becoming stronger all the time.

January 27, 2015

Production of islet-like insulin-producing cell clusters in vitro from adipose-derived stem cells

Diabetes mellitus is a high incidence disease that has increased rapidly in recent years. Many new therapies are being studied and developed in order to find an effective treatment. An ideal candidate is stem cell therapy. In this study, we investigated the differentiation of adipose derived stem cells (ADSCs) into pseudo-islets in defined medium in vitro, to produce large quantities of insulin-producing cells (IPCs) for transplantation. ADSCs isolated from adipose tissue were induced to differentiate into islet-like insulin-producing cell clusters in vitro by inducing medium DMEM/F12 containing nicotinamide, N2, B27, bFGF, and insulin-transferrin-selenite (ITS). Differentiated cells were analyzed for properties of IPCs, including storage of Zn 2+ by dithizone staining, insulin production by ELI-SA and immunochemistry, and beta cell-related gene expression by reverse transcriptase PCR. The results showed that after 2 weeks of differentiation, the ADSCs aggregated into cell clusters, and after 4 weeks they formed islets, 50–400 micrometers in diameter. These islet cells exhibited characteristics of pancreatic beta cells as they were positive for dithizone staining, expressed insulin in vitro and C-peptide in the cytoplasm, and expressed pancreatic beta cell-specific genes, including Pdx-1, NeuroD, and Ngn3. These results demonstrate that ADSCs can be used to produce a large number of functional islets for research as well as application.

January 25, 2015

Targeting specificity of dendritic cells on breast cancer stem cells: In vitro and in vivo evaluations

Breast cancer is a leading cause of death in women, and almost all complications are due to chemotherapy resistance. Drug-resistant cells with stem cell phenotypes are thought to cause failure in breast cancer chemotherapy. Dendritic cell (DC) therapy is a potential approach to eradicate these cells. This study evaluates the specificity of DCs for breast cancer stem cells (BCSCs) in vitro and in vivo. BCSCs were enriched by a verapamil-resistant screening method, and reconfirmed by ALDH expression analysis and mammosphere assay. Mesenchymal stem cells (MSCs) were isolated from allogeneic murine bone marrow. DCs were induced from bone marrow-derived monocytes with 20 ng/mL GC-MSF and 20 ng/mL IL-4. Immature DCs were primed with BCSC-or MSC-derived antigens to make two kinds of mature DCs: BCSC-DCs and MSC-DCs, respectively. In vitro ability of BCSC-DCs and MSC-DCs with cytotoxic T lymphocytes (CTLs) to inhibit BCSCs was tested using the xCELLigence technique. In vivo, BCSC-DCs and MSC-DCs were transfused into the peripheral blood of BCSC tumor-bearing mice. The results show that in vitro BCSC-DCs significantly inhibited BCSC proliferation at a DC:CTL ratio of 1:40, while MSC-DCs nonsignificantly decreased BCSC proliferation. In vivo, tumor sizes decreased from 18.8% to 23% in groups treated with BCSC-DCs; in contrast, tumors increased 14% in the control group (RPMI 1640) and 47% in groups treated with MSC-DCs. The results showed that DC therapy could target and be specific to BCSCs. DCs primed with MSCs could trigger tumor growth. These results also indicate that DCs may be a promising therapy for treating drug-resistant cancer cells as well as cancer stem cells.

February 23, 2015

Optimization of culture medium for the isolation and propagation of human breast cancer cells from primary tumour biopsies

Breast cancer cells from patients hold an important role in antigen production for immunotherapy, drug testing, and cancer stem cell studies. To date, although many studies have been conducted to develop protocols for the isolation and culture of breast cancer cells from tumour biopsies, the efficiencies of these protocols remain low. This study aimed to identify a suitable medium for the isolation and propagation of primary breast cancer cells from breast tumour biopsies. Breast tumour biopsies were obtained from hospitals after all patients had given their written informed consent and were cultured according to the expanding tumour method in 3 different media: DMEM/F12 (Dulbecco's Modified Eagle Medium: Nutrient Mixture F-12) supplemented with 10% FBS (Fetal bovine serum) and 1% antibiotic-antimycotic (Medium D); Medium 171 supplemented with 1X MEGS (Mammary Epithelial Growth Supplement) and 1% antibiotic-antimycotic (Medium M); or a 1:1 mixture of Medium D and Medium M (Medium DB). The cell culture efficiency was evaluated by several criteria, including the time of cell appearance, cell morphology , capability of proliferation, cell surface marker expression, ALDH (Aldehyde dehydrogenases) activity, karyotype, and tumour formation capacity in immune-deficient mice. Notably, primary cancer cells cultured in Medium DB showed a high expression of breast cancer stem cell surface markers (including CD44 + CD24-and CD49f +), low expression of stromal cell surface markers (CD90), high ALDH activity, an abnormal karyotype, and high tumour formation capacity in immune-deficient mice. These findings suggested that Medium DB was suitable to support the survival and proliferation of primary breast cancer cells as well as to enrich breast cancer stem cells. Keywords— Breast cancer cell, breast cancer stem cell, culture medium, primary cancer cell, tumor biopsy.

1 / 11

Please reload

University of Science

Vietnam National University

​Ho Chi Minh city, Viet Nam 

© 2020 Phuc Van Pham.