Introduction: Cancer remains the second cause of death in the world after coronary heart disease. Nowadays, most researchers have focused on specific cancer therapy, without adversely affecting other normal tissues. Mesenchymal stem cells (MSCs) are multipotent adult cells that have been used in cell-based therapy for various diseases. MSCs have been derived from a number of organs like bone marrow, adipose tissue, muscles, fetal liver and the umbilical cord. These cells are characterised by expression of cell surface markers such as CD73, CD90, and CD105, and lack of haematopoietic markers, including CD11b, CD34, and CD45. Literature review: MSCs have a dual role in cancer inhibition or promotion. Some studies have demonstrated that unmodified MSCs have shown antitumour properties in different cancers, like lung and breast cancers, hepatoma, glioma and melanoma, in both in vitro and in vivo models. On the other hand, a growing number of studies have demonstrated that these cells can migrate into the site of tumours. This is due to the fact that some factors like vascular endothelial growth factor which are released from tumour cells can recruit MSCs to differentiate into vascular endothelial cells. Other factors including epidermal growth factor, fibroblast growth factor, platelet-derived growth factor, IL6, IL8, granulocyte colony- stimulating factor, stromal-derived growth factor-1α (SDF-1α/CXCL12), Ang1, granulocyte– macrophage colony-stimulating factor and haematopoietic growth factor, are also important in MSC migration into the tumour sites. Thus, engineered MSCs with different antiproliferative, proapoptotic, antiangiogenic or prodrug converting enzymes including, TRAIL, CX3CL1, CD, IFNα, IFNβ, IL2, IL7, IL12, IL18, NK4, HSV-tk can be used for cancer therapy with high efficiency and limited side effects. Conclusion: Taken together, MSCs are suitable for cell therapy as they are easily isolated, expanded, have immunomodulatory properties and can be easily transduced with different vectors. These cells are able to specifically migrate to, integrate with, and survive in tumour sites. Therefore, genetically engineered MSCs could be useful candidates for cancer therapy. Tumour specific promoters, which are induced in response to tumour microenvironment, like hypoxia, with proapoptotic genes may lead to improved MSC-based therapies, without adversely affecting other tissues.

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