Ricki Lewis

Links between environmental exposures and increases in cancer rates take time to emerge. They range from community-wide disasters, like the 25-year dumping of carcinogens into the former Love Canal in Niagara Falls that caused kidney and bladder cancer, to associations that seem obvious in retrospect, like smoking and lung cancer, sun exposure and melanoma. My breast cancer might have arisen from in utero exposure to diethylstilbestrol (DES), a drug given to pregnant women in the 1950s to calm morning sickness.

The hallmark of an environmentally-triggered cancer is a sudden increase in incidence (rate of new cases over time) and prevalence (total cases at a specific time) of a particular type of cancer that parallels an increase in exposure to a specific chemical, or class of chemicals. A genetic change would take much longer to manifest.

A classic illustration of an environmentally-caused cancer is the increase in lung cancer in the 1950s that followed the pervasive cigarette smoking among the post-World-War-II generation. It was a time when cigarette ads dominated TV, airplanes stunk of stale smoke, and the habit was actually considered attractive. Many people, especially women, felt pressured to smoke to be accepted.

To continue reading, go to DNA Science, where this post first appeared.

I fear that 2025 is ending with a tragic irony: the dismantling of progress in biomedical research, as infectious diseases return and resurge. Arrogance and ignorance are proving to be more dangerous pathogens than bacteria and viruses.

So I thought I'd close out the year with an uplifting look at a funding source not threatened by the current administration: the California Institute of Regenerative Medicine, aka CIRM.

Two Decades of Funding Research, Needed More Now Than Ever

CIRM was born 20 years ago, when 59 percent of California voters approved Proposition 71, and reaffirmed it in 2020. Since then, the taxpayer-supported organization has provided more than 1400 grants, totaling nearly $4 billion.

Grants support all stops on the journey from initial idea to delivering a new treatment. That means funding basic research at universities and supporting education, collaboration, scientific and medical meetings, as well as manufacturing facilities, clinics, hospitals, and community outreach programs.

To continue reading, go to DNA Science, where this post first appeared.

Pluribus, Apple TV+'s sci fi series that just concluded its first season, is a clever take on the alien invasion theme, from Vince Gilligan of Better Call Saul fame. I enjoyed it, but wish the writers had consulted a scientist or two in creating the backdrop of genetics and cell and molecular biology.

The series honors Isaac Asimov's science fiction law of "change only one thing." An alien RNA virus infects people, robbing them of their individuality and their humanity as a "hive mind" forms across the planet, with the exception of thirteen individuals. But the writers demonize RNA (don't we have enough of that?) while conflating egg cells with stem cells.

Does accuracy really matter for plausibility in a sci-fi plot? I suspect I'm in the minority when I say yes, it does.

To continue reading, go to DNA Science, where this post first appeared.

One of my greatest joys in revising my human genetics textbook is adding treatments for genetic diseases that have been FDA-approved since the last edition. The list has grown quite a lot since I finished the last revision as the pandemic finally faded away, and certainly since my gene therapy book was published in 2013. And so I was thrilled a few days ago when the father of a boy who had Menkes disease reposted my DNA Science blog from 2021, which described the rare disease, the clinical trial, and the family's participation.

The "new" treatment – many kids with Menkes have been part of the clinical trial for years – is a simple injection administered daily under the skin that delivers copper, which the body cannot process from food. It's not gene therapy, nor gene editing, nor magic – it is a sensible, decades-old strategy of finding a way around a biochemical glitch. Specifically, the drug Zycubo, aka copper histidinate, is a copper replacement therapy. Cyprium Therapeutics developed the long-awaited treatment.

To continue reading, go to DNA Science, where this post first appeared.

With the pandemic past and vaccine-preventable infectious diseases creeping back, we don't think often about syphilis.

A new report in Science, from Davide Bozzi of the University of Lausanne, Switzerland and colleagues, uses DNA evidence to rewrite what we thought we knew about how and when European explorers brought the sexually transmitted infection here. It turns out, they likely didn't.

The genome sequence from a recently-discovered sample of a close relative of the modern bacterium that causes syphilis, in Sabana de Bogotá, Colombia, backdates the origin of the STI in North America to much earlier than previously thought. So European explorers might have picked the STI up here and brought it home, where it spread in the late 15th century.

The bacterium Treponema pallidum causes syphilis, which belongs to a group of infectious diseases caused by spiral-shaped bacteria (spirochetes) that includes yaws, bejel, and pinta. People have suffered with these diseases for thousands of years, but evidence from human remains is sparse, because the bacteria crumble bones. Obtaining long enough DNA molecules to overlap them and deduce the genome sequence from ancient microbial pathogens has been difficult.

To continue reading, go to DNA Science, where this post first appeared.