In the last year or so I’ve heard a number of stories that just tonight became connected by a volunteer process somewhere in the back of my mind.
HeLa is the one I’ve heard most of.
For those who don’t know HeLa is the shortened version of the name Henrietta Lacks. She is extremely important to medical science. Even though she has been technically deceased for over 50 years I use ‘is’ because her cells live on today. And in many places they perform a valuable service: a consistent set of human cells on which to perform tests and experiments necessary for research and development. This is likely to go on pretty much forever so long after you and I have passed on HeLa will exist.
Early in the 20th century Medical Science began searching for human cells that could live in laboratory conditions, outside the body, and be grown outside the body. This search took tissue samples from many people and then tested them to see if they could survive outside the body. After decades of trying they finally tested cells from Henrietta at Johns Hopkins in 1951 and found what they were looking for.
Since then they’ve learned how to grow other cell lines but HeLa has proved to be the most successful.
This weekend the Quirks and Quarks show had a segment on a not so good aspect of HeLa: It’s a bit of an Invasive Species when it comes to the world of cells.
In 1962 it was discovered that it was hardy enough to survive being an aerosol particle. It could aerosolize, float around, and by 1966 we knew it could land on cells being grown in other labs and not only survive but reproduce and sometimes take over.
The other story that popped up in my head while listening to that was the plight of the Tasmanian Devils.
The population of Tasmanian Devils is being decimated by a pernicious disease. It’s a Cancer that manifests as tumorous growths on and in the animal’s snout hence the moniker: devil facial tumour disease DFTD (wikipedia, U of Cambridge Transmissible Cancer Group,
Tasmanian Devils engage in social discourse and as part of that they bite. This becomes a transfer mechanism for cancerous cells to move from one animal to another.
The scary thing is that these cells can then grow and proliferate and form a tumour. Even though they are not genetically ‘self’ to the new animal it doesn’t matter. For some reason still not completely understood they are able to withstand, or mitigate, the host’s immune response. Major Histocompatibility Complex Class 1 molecules on the cell surface are the main way cells are identified as being self or not self. DFTD cancer cells limit the expression of these MHC1 molecules and that can help them hide from the immune system. They are Cancer cells and they are Immortal: in the simple sense that as long as they are attached to a living Devil they will never die.
This is a Transmissible Cancer. Research has identified a second transmissible cancer involved with the Devils so now they are called DFT1 and DFT2.
In case you haven’t figured out where I’m going with this:
- Some Cancers are transmissible.
- HeLa cells are derived from human Cancer cells.
- HeLa cells are very hardy, enough to become aerosols
- HeLa cells can take over the growth environment they land in
Which leaves me wondering how often a DNA fingerprint of cancer biopsies happens. A visual inspection might be enough to tell if cells are cancerous or not but does anyone go past that point? What would be the point of that – the cancer in that person’s body, lungs must be cells from that person. Right?
Some things to consider:
In the Readers Guide on RebeccaSkloot.com there is mention of ‘Chester Southam begins to conduct experiments without patient consent to see whether or not injections of HeLa cells could cause cancer in 1954’ which leaves me wondering what and where the HeLa cells were injected into.
In this ScienceAlert article they talk of 8 different types of contagious cancer. 1 in dogs, 2 in the devils and 5 in 4 species of molluscs and their relatives. Not only that but we now know of cancer that can be passed between species. These are close relatives genetically speaking but they are different species none the less.
I winder whether anyone has thought to do studies of lab workers who have worked with or near HeLa cells and gone on to develop lung cancer later on.
I did some searching on Chester Southam and Cancer. The story is disturbing.
Depending on which road you take to get to it he could be (and was) likened to World War 2 Nazi doctors conducting experiments on humans without their knowledge or consent (NYPost) . Or he could be looked at as a research doctor willing to do the things necessary to ensure he and others weren’t doing major harm to patients. (HelATerm)
In the opening words of that second link we hear: “Chester Southam, a virologist, wanted to be sure that the cancer in the HeLa cells, which he and other doctors were using for tests, were not contagious. At this time in history, cancer was still a mystery. He assumed there was a valid risk of causing cancer, and as a cancer researcher, he wanted to know for sure (Skloot, 2010, p. 131)”
He began by injecting HeLa cancer cells into patients who already had cancer. In some they developed into tumours that subsequently disappeared. In others the tumours did not disappear but were surgically removed. One patient died from a HeLa cancer. So a HeLa cancer in a host IS a definite, proven, possibility.
Not sure if this was due to their already compromised systems he moved on to injecting HeLa cells into healthy prison inmates. In each case tumours began to grow but the immune system was able to fend them off.
He carried on with studies of this sort with various patients in a number of institutions. Most of the time they had no idea what was being done to them.
He also did testing with other diseases on people in Africa.
In regards to the central question of this post it’s clear that HeLa cells can cause Cancer in foreign (Not Henrietta Lacks) hosts. Whether or not this is a serious problem is down to other factors. Now about those lung cancers . . .