This open access review outlines an interesting basis for the development of targeted cancer treatments in which stem cells are used as the vector to deliver modified genes. This is apparently well underway, progressing at least as well as other targeted cell killing approaches to treating cancer that are currently in laboratory studies and clinical trials. The breadth of different technology platforms forming the next generation of cancer treatments is one of the reasons why I am optimistic about progress towards robust, highly effective therapies for near all forms of cancer.
For practicing clinicians, who treat patients suffering from advanced cancers with contemporary systemic therapies, the challenge is to attain therapeutic efficacy, while minimizing side effects. Unfortunately, all systemic therapies, including chemotherapy, radiation therapy, and radio-immunotherapy, affect to some extent also healthy cells; thus cause side effects. Therefore, there is an urgent need for the patients' personalized and the cancers' targeted therapies.
Stem cells have the unique potential for self renewal and differentiation. This potential is the primary reason for introducing them into medicine to regenerate injured or degenerated organs, as well as to rejuvenate aging tissues. Recent advances in genetic engineering and stem cell research have created the foundations for genetic engineering of stem cells as the vectors for delivery of therapeutic transgenes. One of the most advanced approaches is based on introduction into tumor cells of genes capable for converting a non-toxic pro-drug into a cytotoxic agent. Specifically in oncology, the stem cells are genetically engineered to deliver the cell suicide inducing genes selectively to the cancer cells only. Expression of the transgenes kills the cancer cells, while leaving healthy cells unaffected.
Herein, we present various strategies to bioengineer suicide inducing genes and stem cell vectors. Moreover, we review results of the main preclinical studies and clinical trials. However, the main risk for therapeutic use of stem cells is their cancerous transformation. Therefore, we discuss various strategies to safeguard stem cell guided gene therapy against [this outcome].