The Nobel Prize in Medicine was recently awarded to two researchers in Massachusetts, one at the University of Massachusetts and one at Harvard University. Both men had been working on an obscure bit of cell chemistry called microRNA for decades. As with much in Mother Nature’s kitchen, what initially appeared to be of no consequence has proven to be a vital ingredient in life’s chemistry. MicroRNA is part of the information system of all cells that determines whether a cell becomes part of a muscle or a blood vessel or a pancreas or skin. It turns on or off genes and gene products to produce an animal or a plant that develops, goes through its life cycle, and produces descendants. Most remarkable of all, it is a vital element in the realization of all living things, ranging from worms to whales, from crabgrass to redwoods.
Less than a century ago, the blueprint for life was traced back to a four-letter code preserved in information ribbons called chromosomes. Chromosomes are primarily composed of a material called deoxyribonucleic acid (DNA). Humans have 23 pairs of these ribbons, which prompted a genealogy company to adopt the trademark “23 and me.” The chemicals constituting these ribbons form a double helix, like a spiral staircase. Billions of individual elements that make up the steps of these staircases are translated by the cell containing the DNA ribbons into proteins that themselves are made up of chemical elements vital to life.
Each grouping of DNA chemicals that spells out the formula for making a specific protein is called a gene. The translation of a gene into a protein is dependent upon ribonucleic acid (RNA) that copies the instructions for the protein constituents from the DNA to the cell’s protein manufacturing equipment. Humans have about 25,000 genes. Worms have a similar number of genes.
Worms deserve special mention in this context because much of what we know about genes and genetics is from studies of one, ever-so-humble worm, called Caenorhabditis elegans (aka, C. elegans). This animal is little more than a one millimeter tube that ingests, processes, and excretes plant debris. It develops from a fertilized cell whose development into a full-fledged organism has been studied in more detail than nearly any other multicellular organism. What this year’s Nobel Prize winners discovered was that what had been routinely dismissed for years as an inconsequential type of RNA, now labelled microRNA to distinguish it from other types of RNA, plays a prominent role in determining when and what genes and gene products are switched on or off as the organism, and in fact any organism, develops.
That these worms and people and every other living thing on our little, blue planet have so much in common is both humbling and worrisome. It means that every creature, great and small, shares a vulnerability. For example, there is a gene defect, called eyeless, that occasionally develops in fruit flies that interferes with eye development. There is also a defect that occasionally develops in human genes with a coding structure similar to that of the fruit fly eyeless gene that also disturbs eye development. That organisms (flies and people) share a common vulnerability to a developmental error is unexpected and frightening, given the hundreds of millions of years that these animals have evolved along separate branches of the tree of life.
Simply put, that we have so much in common with worms and whales and fruit flies and fungi places every living thing on the planet at risk from any agent that can disable a vital life process. That our chemistries overlap with those of everything else we call “living” means we and every plant and animal on Earth are in the same boat. Something as simple as a virus that interferes with the production of microRNA could turn the Earth into a lifeless desert.
Given that life on our planet has multiplied and prospered for hundreds of millions (if not billions) of years makes such a transformation highly unlikely. Of course, there is a new species in play that has already had an irreversible impact on the environment during the past few centuries. That is Homo sapiens, our species. Now that we know how vulnerable life is and we know how to disable the machinery and chemistry of life, we can only wonder if our fear and loathing of our fellow humans will prompt someone to use that knowledge of life’s essential elements to rid us of those he (or she) hates or fears.
Dr. Lechtenberg is an Easton resident who graduated from Tufts University and Tufts Medical School in Massachusetts and subsequently trained at The Mount Sinai Hospital and Columbia-Presbyterian Medical Center in Manhattan. He worked as a neurologist at several New York Hospitals, including Kings County and The Long Island College Hospital, while maintaining a private practice, teaching at SUNY Downstate Medical School, and publishing 15 books on a variety of medical topics. He worked in drug development in the U.S., as well as in England, Germany, and France.
