'Relapse Gene' ID'd in Leukemia

In a major breakthrough, scientists have found a gene that appears to be responsible for repeated relapses in a severe form of children’s leukemia.

Hana Levi Julian, | updated: 14:12

Medical laboratory
Medical laboratory
Israel news photo: (illustrative)

Researchers at the University of Melbourne and the Royal Melbourne Hospital have achieved a major breakthrough in the fight for to cure T-cell acute lymphoblastic leukemia, or T-ALL. This form of cancer affects mostly children and teenagers, although adults are attacked, rarely, by the disease as well.

In Israel, approximately 45 new cases of T-ALL are diagnosed each year (a statistic quoted in a 1998 study published by O. Blau in the medical journal, Leukemia Research (Vol. 22, Issue 6)). The disease accounts for some 80 percent of all childhood leukemias in the Jewish State.

According to a study published last week in the journal Science, the LMO2 gene, with its stem-cell-like properties, was identified as that which was able to recover its equilibrium and reassert its ability to grow following the traditional cancer-killing treatments.

Australian research leader Dr. David Curtis said the team he worked with had managed to identify the LMO2 gene that resembled a stem cell, remaining hidden when the cancer appeared to have been eradicated. The stem cell-like gene would eventually reappear – immune to the chemotherapy, radiotherapy and bone marrow transplants used to kill the disease in other cases – and cause life-threatening relapse in 25 percent of cases.

The LMO2 gene also contains a cysteine-rich, two-LIM (Lin 11, Isl-1 & Mec-3) domains’ protein called rhombotin-like 1, known by the same name, “LMO2”.

Principal investigator Dr. Matthew McCormack noted that the cellular origins of this particular type of leukemia “are not well understood... Our discovery that these cells are similar to normal stem cells explains why they are capable of surviving for long periods. It also explains why they are remarkably resistant to treatment."

The researchers are presently working on creating medications to eradicate those cells.

“We can now study it, work out how it is resistant to normal chemotherapy and radiation, and work out better ways to kill those cells, so we can cure not 75 percent of children, but all children,” Curtis explained.

McCormack added that some of the work is also being focused on the thymus cells in hopes of reducing the length and toxicity of the treatment and preventing relapses.

The thymus, a small organ in the upper chest, protects the human body against infections, making it significant in leukemia and other diseases that involve the immune system. The research team discovered that 99 percent of the cells of the thymus gland were destroyed during radiation therapy.