In macroscopic organisms, aging is often obvious; in single-celled organisms, where there is the greatest potential to identify the molecular mechanisms involved, identifying and quantifying aging is harder. The primary results in this area have come from organisms that share the traits of a visibly asymmetric division, and an identifiable juvenile phase. As reproductive aging must require a di...

In the 1910s, Alexis Carrel [4], the French surgeon and biologist, concluded that cells are intrinsically immortal. His claim was based on chick [5]-heart tissue cultures in his laboratory that seemed to be able to proliferate forever. Carrel?s ideas about cellular immortality convinced his many contemporaries that cells could be maintained indefinitely. In the 1960s, however, Carrel?s thesis a...

Crocin, the main pigment of Crocus sativus L., has been shown to have antiproliferative effects on cancer cells, but the involved mechanisms are only poor understood. This study focused on probable effect of crocin on the immortality of hepatic cancer cells. Cytotoxicity of crocin (IC50 3 mg/ml) in hepatocarcinoma HepG2 cells was determined after 48 h by neutral red uptake assay and MTT test. I...

Tumourigenic transformation of normal cells into cancer typically involves several steps resulting in acquisition of unlimited growth potential, evasion of apoptosis and non-responsiveness to growth inhibitory signals. Both genetic and epigenetic changes can contribute to cancer development and progression. Given the vast genetic heterogeneity of human cancers and difficulty to monitor cancer-i...

To ensure species continuity, the tantalising developmental plasticity of early embryonic cells, also called totipotency, must be transmitted to the offspring. This responsibility rests within the reproductive cell lineage: the germ line. At the recent EMBO/EMBL symposium ‘Germline – Immortality through Totipotency’, researchers discussed the mechanisms that establish and control totipotency, w...

To ensure species continuity, the tantalising developmental plasticity of early embryonic cells, also called totipotency, must be transmitted to the offspring. This responsibility rests within the reproductive cell lineage: the germ line. At the recent EMBO/EMBL symposium 'Germline - Immortality through Totipotency', researchers discussed the mechanisms that establish and control totipotency, w...

By analysing microscope images of growing colonies, Eric Stewart and his colleagues at the René Descartes University in Paris, France, proved that direct descendants of old-pole cells grew 2 per cent more slowly, were 3 per cent smaller and were more likely to die (PLoS Biology, vol 3, e 45). Nature, does not seem to do immortality, Stewart says. "Never say never, but in natural organisms it se...