Protein extracts from regenerating lizard tail show an inhibitory effect on human cancer cells cultivated in-vitro

Abstract

Backgroundaccumulating evidence indicates that during tail regeneration in lizards the initial stage of regenerative blastema is a tumor-like proliferative outgrowth that rapidly elongates into a new tail composed of fully differentiated tissues. Both oncogenes and tumor-suppressors are expressed during regeneration, and it has been hypothesized that an efficient control of cell proliferation avoids that the blastema is turned into a tumor outgrowth. Methodsin order to determine whether functional tumor-suppressors are present in the growing blastema we have utilized protein extracts collected from early regenerating tails of 3–5 mm that have been tested for a potential anti-tumor effect on in-vitro culture by using cancer cell lines from human mammary gland (MDA-MB-231) and prostate cancer (DU145). Resultsat specific dilutions, the extract determines a reduction of viability in cancer cells after 2–4 days of culture, as supported by statistical and morphological analyses. While control cells appear viable, treated cells result damaged and produce an intense cytoplasmic granulation and degeneration. Conclusionsthis negative effect on cell viability and proliferation is absent using tissues from the original tail supporting the hypothesis that only regenerating tissues synthesize tumor-suppressor molecules. The study suggests that the regenerating tail of lizard at the stages here selected contains some molecules that determine inhibition of cell viability on the cancer cells analyzed.