Researchers from the California University’s Cancer Centre of San Diego (UCSD) have discovered a method of misleading leukemia cells, forcing them to commit suicide with the help of a gene which initiates cancer development.

Using gene therapy in combination with two remedies, researchers managed to remove the Bcr-Abl molecule, deadly to a cancerous cell, from its initial and permanent position it occupies in a cell cytoplasm into the nuclei. As a result of such a leakage out of cytoplasm, an order for self-destruction is coming to the cell development program and a cancerous cell commits suicide, splitting to an unhazardous dead cellular mass which is then dissolved and processed by other blood cells.

Bcr-Abl is a pathologic protein which is producing when chromosomes, placing the Bcr gene (22^th chromosome) and the Abl gene (9^th chromosome), were changed by mutations occurred as a result of radiation or the influence of other factors and then were by mistake linked together by the DNA normal function, building cells of a body. This sole oncogene causes a chronic myelogenome leukemia (CML), a fatal disease which is attributable to 15-20% of all the patients suffering from leukemia, or appr. 50,000 cases annually worldwide.

Researchers from Novartis, a pharmaceutical company, have developed STI571, a medicinal remedy, which slows down the Bcr-Abl function. STI571 was proved to be extremely successful in clinical tests carried out on patients suffering from CML, at early stages of the disease development. However, STI571 was nor so helpful in treating patients with advanced stages of disease development. Conducting the experiments with the introduction of STI571 in leukemia cells, scientists found that the remedy not only slowed down Bcr-Abl, but also controlled the disease development. Bcr-Abl encourages a rapid growth of blood cells and breaks a structural integrity of leukemia cell cytoplasm. Bcr-Abl have never been found in a nuclei where a DNA genome set existed. It was found that STI571 could make Bcr-Abl enter the nuclei, but leukemia cells quickly “spit it out” back to the cytoplasm. That’s why scientists applied the second medicinal remedy, Leptomycin B, to tight a hole through which a material can be exported from a nuclei; thus, Bcr-Abl remains in the nuclei that is a fatal condition for a cancerous cell as a whole. Organism’s healthy cells are in no way engaged in these processes and thus, they are not damaged.

Combined treatment of patients with the remedies STI571 and Leptomycin B force CML-cells to commit suicide. Specialists managed to completely kill CML-cells in a cultural colony after a 3-day treatment with both remedies.

The UCSD’s Cancer Centre gathered a team of researchers to clinically examine the efficiency of the combined treatment with these 2 remedies. This work not only promises the soonest finding of the CML treatment method, but also opens a new research field which might bring fruit in treating other cancer forms.

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