ABSTRACT
CONTEXT: Through the expression of different immunomodulatory molecules, mesenchymal stem cells (MSCs) play a significant role in the regulation of immune responses against tumor cells. Herein, the expression of major histocompatibility complex class I polypeptide-related sequence B (MIC B) as an immunomodulatory molecule was investigated on adipose-derived stem cells (ASCs) isolated from breast cancer patients (Stage II and III) and healthy individuals. MATERIALS AND METHODS: ASCs were isolated enzymatically, and the expression of MIC B was measured using quantitative real-time polymerase chain reaction method before and after treatment with interferon γ (IFN-γ). The concentration of MIC B in the supernatant of ASCs and also sera of breast cancer and normal individuals were determined using ELISA method. RESULTS: The expression of MIC B in normal ASCs and Stage II ASCs was higher than Stage III ASCs. However, after treatment with IFN-γ expression of MIC B in ASCs was conversely changed as cancer ASCs showed approximately 3.5 fold higher expression of MIC B compared to normal ASCs. The mRNA expression of MIC B in Stage III, Stage II, and normal ASCs showed 61 (P = 0.02), 13 (P = 0.01) and 3 (P > 0.05) fold higher expression after stimulation with IFN-γ compared to cells with no stimulation. CONCLUSION: Expression of MIC B and upregulation of this molecule in response to IFN-γ in cancer ASCs draw attention to the effective role of MSCs in the tumor microenvironment. However, more studies will be needed to further elucidate Natural-killer Group 2, member D (NKG2D) ligands-dependent immunomodulatory roles of ASCs in the tumor progression.
Subject(s)
Adipose Tissue/metabolism , Breast Neoplasms/metabolism , Histocompatibility Antigens Class I/metabolism , Mesenchymal Stem Cells/metabolism , Adipose Tissue/pathology , Breast Neoplasms/pathology , Case-Control Studies , Cell Differentiation/physiology , Cell Proliferation/physiology , Female , Gene Expression Regulation, Neoplastic/physiology , Humans , Immunomodulation/physiology , Interferon-gamma/metabolism , Mesenchymal Stem Cells/pathology , Neoplasm Staging/methods , Tumor Microenvironment/physiology , Up-Regulation/physiologyABSTRACT
MicroRNA (miR), as non-coding small RNA, are key regulators of cancer-related biological cell processes and contribute to tumor growth through regulation of groups of pro- and anti-apoptotic genes. The present study aimed to investigate the effects of miR-29a on the expression of genes involved in apoptosis, including p21, B-cell lymphoma 2 (BCL-2), p53 and survivin. The MCF-7 breast cancer cell line was transfected with anti-miR-29a and treated with Taxol in subdivided treatment groups including: Scramble; anti-miR-29a; anti-miR-29a + Taxol; Taxol; and control. Expression levels of p21, BCL-2, p53 and survivin were evaluated using reverse transcription-quantitative polymerase chain reaction. miR-29a knockdown resulted in p21 and p53 upregulation and a decrease in survivin expression. These results indicated that miR-29a inhibition regulates apoptosis. The present data suggested that miR-29a inhibition may be a promising strategy for the induction of apoptosis of tumor cells.
ABSTRACT
Adipose-derived mesenchymal stem cells (ASCs) are known to have immunomodulatory properties through soluble factors or by direct cell-to-cell contact. This study aimed to assess the expression of HLA-G and IDO activity in breast cancer and normal ASCs and to see whether ASC is capable of modulating both tumor cells and immune system cells in vitro. ASCs were enzymatically isolated from 15 breast cancer patients and 10 normal individuals. Then they were cultured, and the impact of their conditioned media on the movement of the MDA-MB-231 breast cancer cell line was studied in wound healing scratch assay. Next, PBLs from the peripheral blood of normal individuals were separated and co-cultured with breast cancer and normal ASCs. PBLs proliferation and apoptosis were assessed using CFSE labeling dye and annexin V/7AAD staining, respectively. IDO activity and HLA-G protein expression in ASCs were examined using kynurenine assay and Western blotting, respectively. Tumor-derived ASCs, especially those from higher stages of breast cancer, have stronger effects on the proliferation and movement of MDA-MB-231 cells than normal ASCs (P-value < 0.05). Apoptosis in PBLs increased in the presence of ASCs compared to PBLs cultured alone (P-value < 0.05). In contrast, necrosis of PBLs decreased in the presence of ASCs compared to apoptosis in these cells (P-value < 0.001). Collectively, ASCs may have strategic effects on both tumor cells and cells of the immune system in the tumor microenvironment, resulting in tumor development, growth, and metastasis.
