Interferon Makes Dormant Cells Vulnerable
Dormancy is an important protection mechanism of stem cells. First, it protects their genetic material from genetic alterations, which happen primarily during cell division. In addition, dormancy helps them escape attacks of many cytotoxins, which act only on dividing cells. _MNTMany cancer stem cells are likewise dormant, which can protect them from chemotherapy. Waking these cancer stem cells up before chemotherapy is one way to kill more of them, and increasing chances for a remission. Interferon seems to wake stem cells up from a dormant state, and force them to divide. This makes them vulnerable to mutation and to cytotoxins.
Patients suffering from a type of blood cancer called chronic myelogenous leukemia who are treated with a drug called Gleevec almost always relapse after drug treatment has ended. Several patients were given interferon-alpha prior to the Gleevec treatment. Surprisingly, these patients experienced long relapse-free phases without any medication. "We believe that the leukemia stem cells were awakened by the interferon administration and, thus, were sensitized to elimination by Gleevec," Andreas Trumpp explains. _MNTThe other side of the story is that interferon makes normal stem cells vulnerable to cytotoxic agents, so that blood forming stem cells in the bone marrow will be killed by some chemotherapeutic agents such as 5-FU, if interferon is given first. This can cause severe anemia and death.
This knowledge can lead one to speculate about the effects of viral infections and natural interferon on stem cells in other locations, such as the brain. The constant infectious assault experienced in the tropics, for example, may lead to chronic depletion of stem cells with all of the failure of normal regeneration that such depletion implies.
Each scientific discovery becomes the trigger for new exploration. The contemporary human mind cannot keep up with the multiple ongoing chain reactions of knowledge, but computers should be of some help.