"The molecules of benzene arrived in the bone marrow with a crescendo. The foreign chemical surged with the blood and was carried with the marrow spicules of supporting bone into the farthest reaches of the delicate tissue. It was like a frenzied horde of barbarians descending into Rome. And the result was equally disastrous. The complicated nature of the marrow, designed to make most of the cellular content of the blood, succumbed to the invaders.Every cell exposed to the benzene was assaulted. The nature of the chemical was such that it knifed through the cell membranes effortlessly. Red cells or white, young or mature, it made no difference. Within some lucky cells, where only a few molecules of benzene entered, enzymes were able to inactivate the chemical. But in most others, the destruction of the interior cytoplasm was immediate.
Within minutes the concentration of the benzene had soared to the point that thousands of the poisonous molecules had reached the very heart of the marrow, the primitive, finely structured stem cells. These were the actively dividing units, serving as the source of the circulating blood cells, and their activity bore witness to hundreds of millions of years of evolution. Here, being played out, moment by moment, was the incredible mystery of life, an organization more fantastic than the wildest scientific dreams. The benzene molecules indiscriminately penetrated these busily reproducing cells, interrupting the orderly replication of DNA. Most of these cells either halted the life processes in a sudden agonal heave or, having been released from the mysterious central control, tumbled off in frenzied undirected activity, like rabid animals until death intervened.
After the benzene molecules had been washed away by repeated surges of clean blood, the marrow could have recovered except for one stem cell. This cell had been busy for years turning out an impressive progeny of white blood cells, whose function was to help the body fight against foreign invaders. When the benzene penetrated this cell's nucleus, it damaged a very specific part of the DNA but did not kill the cell. It would have been better if the cell had died, because the benzene had destroyed the fine balance between reproduction and maturation. The cell instantly divided and the resulting daughter cells had the same defect. No longer did they listen to the mysterious central control and mature into normal white blood cells. Instead they responded to an unfettered urge to reproduce their altered selves. Although they appeared to be relatively normal within the marrow, they were different from other young white blood cells. The usual surface stickiness was absent, and they absorbed nutrients at an alarming gluttonous rate. They had become parasites within their own house.
After only twenty divisions, there were over a million of these lawless cells. By twenty-seven divisions there were over one billion. They then began to break away from the mass. First a trickle of altered cells entered the circulation, then a steady stream, finally a flood. These cells charged out into the body, eager to establish fertile colonies. By forty divisions, they numbered over a trillion.
It was the beginning of an aggressive, acute myeloblastic leukemia in the body of a pubescent girl, starting November 3rd. two days after her thirteenth birthday. Her name is Nicole and she had no idea except for a single symptom... She had a fever."
When I was in college, my area of specific interest was viral mutagenesis. Why do virii mutate? What caused HTLV I to mutate to HTLV II and then HTLV III, (better known as the HIV virus)? Was it some antigen? Evolution? G-d? We'll probably never know exactly, but it makes us wonder what triggers a cell to mutate?
We know that carcinogens in cigarette smoke cause certain types of cancer in humans. Ok, then at what point do the targeted cells mutate? Years of exposure? Does it depend on the subjects own immunity? Are humans prone to be immune to certain types of malignancy? I believe this. Given what we expose ourselves to on a daily basis. We are able to repair the DNA in our skin after exposure to UV rays. There is a genetic condition called Xeroderma Pigmentosum, in which the body cannot repair tissue damage caused UV exposure. These poor souls are in a sense, similar to vampires, in that the Sunlight can effectively kill them, although, not as quickly. When UV enters the nucleus of a cell, like a typical keratinized, squamous epithelial cell, (skin cell), the DNA helix of that cell is damaged, specifically, gene p53. Normally the body repairs it with a nucleotide excision, don't worry, I'm not going to bore you with that stuff.
In some instances, the repair is insufficient or does not complete. In most cases, the cell usually dies. But in others, this genetically altered cell can divide. If it does, and depending on the mutation specifically and why type of cell that is damaged, it can be of any number of malignancies, like the common cancer involving melanocytes, or the cells that give us our pigmentation, the well media-hyped, Melanoma.
Kind of leave you with a sort of .. “oh” feeling.
I guess the point of all of this is that nothing is perfect in a complex system and things do happen, even if we plan for every possible event in our lives.
I'm no oncologist or histologist, I've just always had a great desire to learn about why things happen.
Perhaps, I should get .. Oh wait, House (MD), is on!
