Morphine can inhibit the blood supply to tumors and thus slow their growth – an article on this topic is published in the American Journal of Pathology.
Morphine was extracted from opium in 1804, and although many new painkillers have been developed since then, it is still used to treat moderate to severe cancer pain.
Recent work by scientists from the University of Minnesota in Minneapolis indicates that this approach can be very beneficial for patients, as morphine also has anti-cancer effects.
The experiments were carried out in model mice to study lung cancer. Some of them were implanted with an implant, which slowly and systematically released morphine, thanks to which the drug reached the concentration in the blood of rodents corresponding to the doses used in pain therapy (250-400 nanograms per milliliter). The results obtained were compared with the group given a placebo.
It turned out that morphine clearly inhibited the formation of new vessels (angiogenesis) in neoplastic tumors, and thus significantly slowed down the growth of these tumors. The analysis confirmed that in mice implanted with a morphine implant, the vascular network was much less frequent and the vessels shorter and less branched.
The researchers also found that morphine exerted its effects through the opioid receptor. In rodents lacking this receptor due to genetic manipulation, no anti-tumor effects of morphine were observed; similar to mice in which the receptor was blocked with the drug naltrexone.
As the authors of the study reminded, angiogenesis is a process necessary for a tumor for further growth. Without the blood vessels to supply it with nutrients and could be the pathway for cancer cells to travel to other organs, it would not be able to grow larger and metastasize.
Therefore, according to Dr. Sabita Roy, who participates in the study, the latest discovery indicates that morphine may be used in the future in oncology not only as an analgesic, but also as an anti-cancer drug. (PAP)