The research team led by scientists at the University of San Francisco developed a preparation for treating breast cancer with a triple-negative phenotype, aggressive subtype of disease, in which patients recover in one case out of five. Opening experts is particularly valuable because drugs that act on the detected protein PIM1, are used in clinical trials for the treatment of leukemia and multiple myeloma.
Triple negative cancer contains receptors for estrogen and progesterone, and patients with this disease is not suitable treatment using modern highly hormonal therapy or HER2-targeted drug Herceptin.
"I'm an oncologist, I saw a lot of patients who die of triple negative cancer - said senior author Andrei Goga, MD -. The only treatment that we offer - it is chemotherapy, and we need new opportunities."
The study, published October 24, 2016 in «Nature Medicine», devoted to the triple-negative breast cancer, which is characterized by high levels of MYC protein. MYC level in triple negative tumors than in tumors expressing receptors for hormones or HER2.
MYC protein expression
MYC was discovered 30 years ago in the laboratory of Nobel laureate George. Michael Bishop, MD, and has long been considered a protein is not treatable.
To solve this problem, the research team used the approach of "synthetic lethality", which includes the identification and study of other proteins that are "lean" type MYC proteins that cause cancer growth.
Experiments have shown that MYC is dependent on a number of kinases, in particular PIM1, to encourage cell growth.
Researchers have found that mice lacking the PIM family of kinases, is slightly less than normal rodents and stressed that the preparation is aimed only at PIM1, it has a controlled level of toxicity in patients with breast cancer.
To assess whether PIM1 plays an appropriate role for these patients, scientists have determined the level of expression in tissue samples PIM1 with MYC cancer patients.
The research team tested two preclinical drug PIM1 inhibitor of MYC-positive cancer. During experiments PIM1 inhibitors kill cells: in one case, the mice implanted with tumor of the patient, and in another - predetermined genetic change MYC tumor development and introduction PIM1 inhibitor led to significant tumor regression.
As a confirmation of these results in another article, researchers from the Institute of Cancer Research in London, led by Professor Andrew Tutt in the same issue of «Nature Medicine» named PIM1 target of triple negative cancer, and a team of experts from London, using very different methods, has come to the same results.
Based on materials medicalxpress.com