A discussion about the vicissitudes of aging led a friend of mine to say, “There are three stages of life — youth, middle age and, “You’re looking good.”
Mortality serves a purpose beyond dark humor. If the Mulkerin clan switched on a gene that made us live forever on earth, we’d become a tumor. We’d grow exponentially, gobble up resources and threaten the planet.
The cells in our body have built-in mechanisms that limit their longevity. When that system fails, tumors develop.
The more invasive ones become cancers. In my last article, I asked you to consider a polyp in the colon. The pathologist looks for signs of abnormal growth that may include a change in the size and shape of a cell, increased mitoses, distorted-looking nuclei and other features.
The microscope gives us a pretty reliable indication about what happened to cell chemistry, but it’s imperfect. Some authors contend a large percentage of things we treat as cancers, aren’t malignant at all.
They point especially at prostate and breast cancers. Like the science of climate change or mental illness, we look at multiple lines of evidence and try to predict where we’re headed. I plan to do a series of articles about the way cancer develops, what factors seem to be most important and what we can do to protect ourselves. The articles will be shorter than earlier ones.
President Nixon led us into the war on cancer in 1971. I was young then, and shared his vision that cancer was one disease and that it was vulnerable to a linear attack. But cancer has dropped more land mines than ever blocked the Iran-Iraq border.
Science is making enormous strides in sorting out the truth. I’ll begin with the issue of cellular immortality. As usual, I invite an exchange of perspectives and a clarification of facts, where necessary.
The cells in our body can be destroyed by injury, releasing their contents and stimulating inflammation. Another process called programmed cell death — apoptosis (I pronounce it Ap-oh-toe-sis) — shows cell contraction and a breakup of its nucleus and other structures. This kind of death is coded in our DNA and it is seen in many situations, including the onset of menstruation and remodeling of our neural system.
For now, I’ll continue to present DNA as a form or template that turns things on and off by controlling the products of a cell.
Some proteins, functioning as enzymes, can initiate their own destruction or that of other cells.
If our DNA takes a hit in one of those spots, old cells, damaged cells and virally infected cells may keep reproducing.
Understanding the huge complexities of cell death may open new ways of fixing the defects. Studying colon polyps and cancers has been a useful way of doing this exciting work.
We can look at abnormalities through fiber-optic scopes, and we can take specimens at different stages of disease. Top scientists have figured out what parts of life’s template have been attacked and by what. The next steps will be to go beyond the guessing stage and the wild claims of crackpots and design a better future to achieve the goals that Richard Nixon embraced.
A short technical note: Dr. Bert Vogelstein moved from cancer treatment to research, in frustration about the death of a child. Any oncologist has felt that sting painfully often.
Few have accomplished Vogelstein’s dreams. He identified TP53 in colon cancers. Surprisingly this gene, this segment of DNA on chromosome 17, coded for a protein that appeared to oppose tumor suppression.
Over time, it became clear this protein, also known as p53, could initiate apoptosis and perform other functions related to controlling cell proliferation.
Thousands of mutations have been identified. It is clear p53 is involved in many kinds of the deadly cancers. Vogelstein and others have expanded into new areas. In the future, we will be able to think beyond killing cancer. Our tools will be better than the system that may be overdiagnosing malignancy.
Next time, I’ll return to the look through the colonoscope and the ways we can use today’s knowledge to manage one of the major cancers that affects American lives and strains the American economy.
Dr. Larry Mulkerin is a retired clinical professor. He can be reached at email@example.com.