FOUND A TARGET PROTEIN FOR LEUKEMIA

 – Rome, 02 Jan. – As reported in the journal Nature, scientists have in fact discovered the secret of the immortality of cancer stem cells, i.e. those few cells that are the root and infinite reservoir of the tumor, often making it incurable: it is 'p21', a 'pit stop' protein of the cell cycle. P21, that is, temporarily blocks the proliferation of cancer stem cells and gives them time to repair their DNA before 'restarting', i.e. before starting to 'churn out' other cancer cells again. The discovery is due to the team of Pier Giuseppe Pelicci, Scientific Director of the Experimental Oncology Department of the European Institute of Oncology, in collaboration with the Universities of Milan and Perugia and was made possible thanks to funding from the Italian Association for Cancer Research ( AIRC), the Ministry of Health, Cariplo and the European Community. By hitting p21 in leukemia stem cells, Pelicci's team managed to deprive them of their immortality: without p21, the stem cells began to accumulate damage to the genome and therefore die, and with them also the entire tumor. In recent decades, oncology has made great strides in finding curative drugs for many tumors: but for many neoplasms these drugs are not enough, the tumor returns, often more ferocious than before. Later it was understood that this depends on the fact that behind millions of tumor cells that therapies often manage to kill, there is, well hidden, a handful of stem cells progenitors of the disease. These stem cells, numerically small compared to the tumor mass, are the reservoir of cancer, they endlessly produce other diseased cells. Cancer stem cells do not respond to the oncological drugs in use today. In fact, these drugs are only active against rapidly reproducing cells such as tumor cells, instead cancer stem cells are more 'smart', they reproduce slowly and escape treatment. Now, however, with the Italian discovery, the circle is closed; Pelicci's group has realized that the slowness with which cancer stem cells reproduce is their salvation for another reason as well: it gives them more time to 'do the revision' and hit the ground running by feeding the tumor again. The p21 protein basically makes them do the pit stop during which the stem cells repair their DNA. Without the pit stop, stem cells would slowly accumulate genetic damage, age and die like all cells. (sn)