{"id":384137,"date":"2025-08-30T03:39:16","date_gmt":"2025-08-30T03:39:16","guid":{"rendered":"https:\/\/www.europesays.com\/uk\/384137\/"},"modified":"2025-08-30T03:39:16","modified_gmt":"2025-08-30T03:39:16","slug":"why-line-1-might-be-the-key-to-cancer-and-aging","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/uk\/384137\/","title":{"rendered":"why LINE-1 might be the key to cancer and aging"},"content":{"rendered":"

In our latest episode of Lexicon<\/a>, we sat down with Dr. Liam Holt<\/a>, associate professor at NYU Langone Health<\/a>, to discuss one of the most enigmatic parts of the human genome, LINE-1.\u00a0<\/p>\n<\/p>\n

When scientists first cracked the human genome, they expected to find treasure such as genes that would explain life, health, and disease. Instead, they discovered that only about 1% of our DNA codes for proteins. The rest? Largely dismissed as \u201cjunk.\u201d<\/p>\n

But, it turns out, so-called junk holds secrets that could change how we understand cancer, aging, and even human evolution. Let\u2019s find out how.<\/p>\n

Also, subscribe to IE+<\/a> for premium insights and exclusive content!<\/p>\n

What is LINE-1?<\/p>\n

\u201cThere are half a million LINE-1 elements in your genome\u2014compared to just 20,000 human genes,\u201d Holt told us. \u201cFor every one gene, there are 20 LINE-1s. We are more LINE-1 than gene,\u201d he added.<\/p>\n

LINE-1, or Long Interspersed Nuclear Element-1, is a retrotransposon, or a segment of DNA that copies and pastes itself throughout the genome. Unlike viruses that infect us from the outside, LINE-1 has co-evolved within us for millions of years, passing from parent to child, generation to generation.<\/p>\n

\u201cThey\u2019ve been called selfish DNA,\u201d Holt explains. \u201cThey replicate themselves and expand their number over evolutionary time. For a long time, people thought they were just like viruses\u2014parasitic passengers with no real function,\u201d he added.<\/p>\n

But that view has changed. Researchers now believe LINE-1 may be both a genomic threat and a crucial evolutionary force.<\/p>\n

From genetic junk to evolutionary driver<\/p>\n

Despite their chaotic tendencies, LINE-1 elements have made significant contributions to reshaping the human genome.<\/p>\n

\u201cThey\u2019ve done really interesting things to create evolutionary change,\u201d says Holt. One example: the loss of tails in apes.<\/p>\n

\u201cOne of these elements (or something like it) jumped into a gene and disrupted it. That disruption appears to have helped early apes lose their tails. That\u2019s evolutionary impact in real time,\u201d he added.<\/p>\n

This capacity to cause significant changes rapidly may help explain sudden evolutionary leaps, a concept popularized by thinkers such as Richard Dawkins. \u201cLINE-1 is one mechanism by which you can get big changes,\u201d Holt explained.<\/p>\n

But the same mechanisms that can transform species can also destabilize individuals, sometimes with devastating consequences.<\/p>\n

When LINE-1 turns against you<\/p>\n

LINE-1\u2019s ability to jump around the genome poses a constant threat to genetic stability. Fortunately, our cells have developed a suite of defenses to keep it in check.<\/p>\n

\u201cThere\u2019s a huge amount of cellular machinery dedicated to silencing these elements,\u201d Holt explains. \u201cOnly about 100 LINE-1s in your genome are even capable of being active. And most of those are being repressed by default,\u201d he added.<\/p>\n

But when that repression system breaks down (as it does in cancer), the consequences can be dire.<\/p>\n

\u201cIn cancer, that machinery tends to fail,\u201d Holt says. \u201cYou get a big increase in the expression of these elements. That might cause the cancer cells to mutate more rapidly and progress more quickly,\u201d he added.<\/p>\n

In fact, some researchers are investigating whether LINE-1 can serve as a biomarker for cancer, i.e., a genomic marker for early detection.<\/p>\n

The role of LINE-1 in aging and inflammation<\/p>\n

LINE-1 also appears to play a crucial role in aging, especially by triggering the body\u2019s inflammatory responses.<\/p>\n

\u201cA huge thing that is strongly associated with aging is inflammation,\u201d Holt explains. \u201cAnd LINE-1 is being considered as a driver of that inflammation,\u201d he added.<\/p>\n

As we age, our ability to repress LINE-1 activity diminishes. When LINE-1 elements activate, they mimic viral infections, producing RNA-DNA hybrids that our immune system mistakenly identifies as invaders.<\/p>\n

\u201cThe immune system sees that as a threat and turns on an inflammatory response,\u201d Holt says. \u201cThat inflammation can damage tissues over time\u2014and that\u2019s what we see in aging and in diseases like arthritis and neurodegeneration,\u201d he explained.<\/p>\n

This process may also be linked to motor neuron disease, including ALS. Holt references the work of his colleague, Molly Gale Hammell, who found elevated LINE-1 activity in certain subtypes of the disease.<\/p>\n

Can we silence the rogue element?<\/p>\n

Given its connection to cancer, inflammation, and aging, scientists are investigating methods to silence LINE-1, or at least reduce its activity.<\/p>\n

\u201cMost efforts are along the lines of silencing its activity,\u201d Holt says. One promising approach involves repurposing reverse transcriptase inhibitors, a class of drugs originally developed to treat HIV.<\/p>\n

\u201cLINE-1 relies on the same RNA-to-DNA copying mechanism that retroviruses do,\u201d Holt explains. \u201cAnd drugs that block that process in HIV may also block LINE-1 replication,\u201d he added.<\/p>\n

However, there\u2019s a catch: telomerase, the enzyme that maintains the ends of our chromosomes (telomeres), also uses reverse transcriptase. Targeting LINE-1 without harming telomerase is a tricky balancing act.<\/p>\n

\u201cIf you turn off LINE-1 to prevent aging, you might accelerate aging by degrading your telomeres,\u201d Holt cautions.<\/p>\n

Genetic glue and cancer progression<\/p>\n

In Holt\u2019s most recent research, his team uncovered a new mechanism by which LINE-1 may cause cellular chaos. The key player? A protein called ORF1, produced by the LINE-1 element itself.<\/p>\n

\u201cORF1 forms a sort of sticky protein cluster that wraps around LINE-1\u2019s RNA. It looks like glue\u2014and it can literally stick two chromosomes together,\u201d says Holt.<\/p>\n

\u201cWhen a cell tries to divide, it pulls those chromosomes apart. But if they\u2019re stuck together, you get missegregation, chromosomal errors\u2014and that could drive cancer progression,\u201d he added.<\/p>\n

This idea that LINE-1\u2019s own machinery may physically disrupt chromosome separation offers a new way to understand genome instability in cancer cells.<\/p>\n

The evolutionary trade-off<\/p>\n

So why does LINE-1 persist? Why didn\u2019t evolution eliminate it?<\/p>\n

\u201cIt\u2019s an occupational hazard of being a species that evolves,\u201d Holt says. \u201cEvolution needs LINE-1 for long-term change\u2014but when it hits you in the short term, it\u2019s usually not great,\u201d he added.<\/p>\n

In other words, LINE-1 is a genetic gamble. It fuels innovation but sometimes breaks the system.<\/p>\n

\u201cIt\u2019s like throwing spanners at your car hoping to improve it,\u201d Holt jokes. \u201cMost of the time, it\u2019s not going to work. But once in a while, something sticks,\u201d he added.<\/p>\n","protected":false},"excerpt":{"rendered":"In our latest episode of Lexicon, we sat down with Dr. Liam Holt, associate professor at NYU Langone…\n","protected":false},"author":2,"featured_media":384138,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3846],"tags":[1502,267,105,358,70,16,15],"class_list":{"0":"post-384137","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-genetics","8":"tag-biology","9":"tag-genetics","10":"tag-health","11":"tag-inventions-and-machines","12":"tag-science","13":"tag-uk","14":"tag-united-kingdom"},"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@uk\/115115639680391461","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/384137","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/comments?post=384137"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/384137\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media\/384138"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media?parent=384137"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/categories?post=384137"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/tags?post=384137"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}