Scientists Managed To Create Engineered Cancer-Killing T-Cells That Target Melanoma
Scientists from University of California – Los Angeles have managed to determine stem cell to differentiate into a type ofÂ engineered T-cells that targetÂ cancerÂ cells in human model patients suffering from melanoma. TheseÂ cancer killing T-cells could hep about 40 percent ofÂ Caucasian patientsÂ that areÂ experiencing this awful disease.
Previous studies have demonstrated that human stem cellsÂ can be determined to differentiate after genetic alteration, intoÂ melanoma fightingÂ T-cells in mouse models.
Jeroma Zack, seniorÂ author and his team now tried toÂ prove thatÂ engineered T-cells have the ability to attackÂ cancer cellsÂ in a relevant modelÂ of human disease – melanomaÂ . The researchers discovered that the engineeredÂ cells have functioned as designed, attacking cancer cells.Â The study was publishedÂ Â in the online edition of Proceedings of the National Academy of Sciences journal.
EveryÂ cell in the human body posses its own type of antigens,Â and for this study researchers used a clonedÂ T-cell receptor that binds with a particularÂ melanoma cancer cell antigen. Afterwards, they modified the blood stem cellsÂ by inserting in their nucleus genesÂ that code the T-cell receptorÂ using a viral vector. The genes are incorporated in the stem cells DNA enabling them to beÂ able to differentiate into cancer-fighting cells only when needed. The best partÂ is that only a small part of the engineered stem cell can differentiate intoÂ specific cancer fightingÂ T-cells when they sense the presence of the melanoma antigen. These type of genetically modified stem cells can remain dormant in the blood periphery and only start to replicate when melanoma antigen stimulates them.
During the research, the engineered blood stem cells were injected into a human thymus ( the body’s site of T-cell differentiation) and then implanted in mice. This approach made possible studying the humanÂ immune system response to cancer using a living model. After 6 weeks, the genetically modified stem cells differentiate into specific melanomaÂ T-cells that started to attackÂ the desiredÂ cancerous cells.Â Furthermore, the mice were implanted two different types of melanoma, one with the specific antigen that stimulates the genetically modified T-cells to differentiate and one melanoma type that did not. The genetically modified cellsÂ were attracted only by the cancer type that expressed the specific antigen; the control tumor remained untouched.
The study was conducted on nine mice, in four subjects the melanomas that presented the expression of the specific antigen were completely disposed. In the remaining five mice, a significant decrease of tumor size was noticed.
The results are quite promising as scientists now hope to be able to genetically modify stem cells to differentiate into engineered T-cells that coud fight different types of cancers like breast cancer or prostate cancer. The the downside is that their function is not a long-term one and more and more engineered T-cells need to be produced to sustain this kind of immune response. One possible solution would be engineering both the peripheral T-cellsÂ and the bloodÂ stem cells linesÂ to differentiate into this king of cancer seekingÂ T-cells.