While iPS cell technology has shown promising results in the field of regenerative medicine, which restores tissues and organs, Professor Yamada Yasuhiro of the University of Tokyo had been using iPS cells to study the mechanism of diseases such as cancer. In recent years, research aimed at uncovering the aging process has also been gaining momentum, and there is growing attention on the possibility of rejuvenating aged cells, as resetting a cell\u2019s destiny through iPS cell technology could, in theory, reverse functional decline associated with aging.<\/p>\n
\u201cFrom a cellular level, iPS cells can be generated from a cell regardless of how aged it is,\u201d says Yamada. \u201cWe can\u2019t say when, but there\u2019s no doubt that this is a technology that may one day make biological rejuvenation a reality.\u201d<\/p>\n
Anti-aging research using iPS cells has become a hot topic globally in recent years. Particularly drawing interest is research using a method called \u201cpartial reprogramming\u201d in which cells are not fully converted into iPS cells but are partially reprogrammed, thereby reversing some characteristics of aging.<\/p>\n For example, Altos Labs, an anti-aging research startup established in 2021, drew attention after receiving major funding from Amazon founder Jeff Bezos.<\/p>\n In March 2022, the Salk Institute for Biological Studies and Genentech, a subsidiary of the Swiss pharmaceutical giant Roche, reported in the journal Nature Aging that they had partially reprogrammed the cells of middle-aged and older mice to make iPS cells using four genes, known as \u201cYamanaka factors,\u201d and had succeeded in reversing the signs of aging including functional decline. Longer-term observations showed no increase in cancer or other health problems. The study made headlines for potential future applications in humans, such as in treatment of age-related neurodegenerative diseases or increasing cellular functionality and recovery.<\/p>\n Understanding the Mechanisms of Aging<\/p>\n Yamada is also following these developments closely, but advises caution. \u201cWe shouldn\u2019t jump to the conclusion that we can simply prevent aging through partial reprogramming of cells. In fact, the research hasn\u2019t even reached the starting line yet.\u201d<\/p>\n Indeed, notes Yamada, a different study from the above-mentioned one published in Nature Aging reports that inducing Yamanaka factors in the cells of progeria mice for two days followed by five days of withdrawal in repeated cycles extended the lifespan of the mice by 20% to 30%. \u201cBut when it comes to why the lifespan was extended and which cells are involved,\u201d he says, \u201cthe mechanism remains largely unknown.\u201d<\/p>\n Yamada points out that the challenge is that the phenomenon of aging itself has not yet been fully understood at a molecular level. \u201cWe still don\u2019t understand what aging truly is, or how cellular aging relates to aging of the entire body. Even if we can extend the lifespan of mice, we have no idea how partial reprogramming affects living organisms as a whole, or whether it\u2019s safe for humans. Reprogramming cells with iPS technology means that skin cells are no longer skin cells and bone cells no longer bone cells. Not only does this not constitute \u2018rejuvenation,\u2019 but it would make life as an organism impossible. So it\u2019s not as simple as the headlines might suggest. The research is just barely getting off the ground.\u201d<\/p>\n Rejuvenation and the Risk of Cancer<\/p>\n The reason Yamada emphasizes caution is because he himself is engaged in researching the mechanisms of cancer through the partial reprogramming of cells. Alarmingly, there is the possibility that reprogramming, rather than promoting rejuvenation, could actually increase the cancer risk.<\/p>\n \u201cWe know that cells can become cancerous when DNA sequence is damaged due to the harmful substances in tobacco, radiation, and such,\u201d Yamada says. \u201cHowever, in the past twenty years, we\u2019ve come to understand that even if the DNA sequence is intact, cancer can still develop from irregular execution of DNA instructions.\u201d<\/p>\n The system that regulates gene function, rather than gene sequence, is called the epigenome. Methyl groups can attach to or detach from cytosine (one of the four chemical bases that make up DNA), and proteins in the cell nucleus called histones can undergo chemical modifications, thereby determining which DNA blueprints are turned on or off. The cellular reprogramming of iPS cell technology can be seen as a method that artificially resets or alters the epigenome without changing the underlying DNA sequence.<\/p>\n \u201cOur research team found that inducing Yamanaka factors in mice for just one week result in the development of pediatric-like cancer during the reprogramming process,\u201d explains Yamada. \u201cUsing a mouse model, we demonstrated that incomplete reprogramming can cause cancer, revealing that changes in the epigenome can have the same effect that DNA damage can.\u201d<\/p>\n Both Yamada\u2019s group\u2019s study and the previously mentioned anti-aging study used incomplete or partial reprogramming, rather than full reprogramming of cells. However, the difference in just a few days in duration produced two very different outcomes\u2014cancer in one case and lifespan extension in another.<\/p>\n![\"(\u00a9](\"https:\/\/www.newsbeep.com\/au\/wp-content\/uploads\/2025\/11\/2894675.jpg\")
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