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CHANGING PARADIGM. "Nevertheless, what seemed in the 1950's to be incontrovertible evidence that the fate of all cultured cells was immortality, soon fell to new insights and a preponderance of opposing information." http://protein.bio.msu.ru/biokhimiya/contents/v62/full/62111380.html View in LinkedIn

TRANSFORMING CELLS. "Immortal cell populations still occasionally arise spontaneously from normal cell cultures by an unknown process. Today, however, they can be created purposely, albeit at low efficiency, by exposing normal, mortal cells to radiation, chemical carcinogens or certain oncogenic viruses." http://protein.bio.msu.ru/biokhimiya/contents/v62/full/62111380.html View in LinkedIn

TENABLE. "I think it is fair to say that our suggestion that the Phase III Phenomenon is aging at the cell level is still a tenable hypothesis even after thirty years of study. That is not to say that it has been proven unequivocally to be correct. This has not happened because there are no universally accepted criteria for defining biological aging." http://protein.bio.msu.ru/biokhimiya/contents/v62/full/62111380.html View in LinkedIn

NAIL IN COFFIN TO HYPOTHESIS. "Cells aging in vitro do, indeed, acquire hundreds of incremental and decremental physiological changes as the approach the end of their in vitro lifespan. Yet, none of these changes raise the cell to a higher level of differentiation or specialization. To call the Phase III Phenomenon differentiation seems entirely inappropriate." http://protein.bio.msu.ru/biokhimiya/contents/v62/full/62111380.html View in LinkedIn

PROPERTIES OF MORTAL CELLS #4. "Human cell strains will not produce tumors when inoculated into the hamster cheek pouch or even when directly inoculated into terminal human cancer patients." http://protein.bio.msu.ru/biokhimiya/contents/v62/full/62111380.html View in LinkedIn

TERMINAL DIFFERENTIATION HYPOTHESIS. "Presently, the only alternative explanation of the limited proliferative capacity of normal cells that competes with the notion that it represents aging at the cellular level is the conjecture that it might represent terminal differentiation." http://protein.bio.msu.ru/biokhimiya/contents/v62/full/62111380.html View in LinkedIn

PROPERTIES OF MORTAL CELLS #3. "If derived from normal tissue, cell strains have the diploid karyotype and unlike immortal cell lines, normal cell strains are incapable of replication in suspension culture. This property is now called anchorage dependence." http://protein.bio.msu.ru/biokhimiya/contents/v62/full/62111380.html View in LinkedIn

CONCLUSION #3. "Direct Relationship between Species Lifespan and Population Doublings of Their Cultured Normal Cells. Several years ago we suggested that the population doubling potential of cultured fibroblasts from several animal species revealed a surprisingly good direct correlation with maximum species lifespan." http://protein.bio.msu.ru/biokhimiya/contents/v62/full/62111380.html View in LinkedIn

PROPERTIES OF MORTAL CELLS #2. "Human diploid cells undergo a number of population doublings inversely proportional to donor age. This suggested to us that the finite replicative capacity of cultured normal cells is an expression of aging at the cell level. This notion received considerable experimental support in subsequent years and became the basis for the field of cell aging." http://protein.bio.msu.ru/biokhimiya/contents/v62/full/62111380.html View in LinkedIn

CONCLUSION #2. "Changes That Precede Phase III. More than two hundred changes in biological activity have been shown to occur in cultured normal human fibroblasts as they age in vitro. Of great importance is that many of these changes are identical to the changes recognized as characteristic of aging in intact humans." http://protein.bio.msu.ru/biokhimiya/contents/v62/full/62111380.html View in LinkedIn