Cancer is a plague of modern man. That's partly because we live longer and have commensurate opportunity to get sick. It's partly because almost all multicellular life forms get cancer, with a few exceptions such as naked molerats and sharks (which are relatively insusceptible). And it's partly the result of unhealthy lifestyle.
Many have suspected that colon cancer is an artifact of an inadvisable lifestyle. Colorectal cancer has clear correlations with obesity, physical slothfulness, and eating processed foodstuffs. But the disease is also known to have a genetic component.
So: are our degenerate lifestyle choices causing mutation? Or was there already a preexisting genetic mechanism? Put otherwise, if our ancestors could have lived long enough to develop colorectal cancer, might they have?
New research by Tel Aviv University on one 300-year old Hungarian mummy did find the colon cancer mutation, apparently – genetic sequencing and interpretation are not quite as clear-cut as many seem to think.
But the conclusion is clearly that a genetic predisposition to colorectal cancer preceded potato chips and television.
“Colorectal cancer is among the most common health hazards of modern times,” says Dr. Rina Rosin-Arbesfeld of TAU’s Department of Clinical Microbiology and Immunology at TAU’s Sackler Faculty of Medicine. “It has a proven genetic background. We wanted to discover whether people in the past carried the APC mutation — how common it was, and whether it was the same mutation known to us today. In other words: Is the increase in the incidence of cancer the result of man's manipulation of nature alone?"
APC stands for "adenomatous polyposis coli". The APC gene codes for the APC protein, which is involved in regulating cellular division and is believed to be a cancer suppressor. A lot of APC mutations are known; the most commonly found mutation in the context of colon cancer is inactivation of this protein.
Sealed in the crypt
Examining the state of our forefathers' APC protein genes requires us to have our forefather's bodies, in a decent state of preservation. Serendipitously, 18th century corpses in a rare state of preservation were found in sealed crypts in the Dominican church in Vác, Hungary. In 1995, more than 265 of them in a state of partial or total mummification were removed for study.
The crypts had been used from 1731 to 1838 to inter middle-class families and clerics, and had unusually appropriate microclimatic conditions for natural mummification — cool temperatures, low humidity and ventilation.
Several teams descended to study these rare ancient remains. A different team discovered, for instance, that the Hungarian mummies had diverse strains of tuberculosis.
If even Neanderthals can be sequenced, analyzing the genome of these mummies was, relatively, child's play. Rosin-Arbesfeld teamed up with colleague Ella H. Sklan and Prof. Israel Hershkovitz, also of Tel Aviv University. The three flew to Budapest. The Israeli scientists looked for mutations in APC genes that were isolated from the mummies.
“Mummified soft tissue opens up a new area of investigation,” explains Prof. Hershkovitz. “Very few diseases attack the skeleton, but soft tissue carries evidence of disease. It presents an ideal opportunity to carry out a detailed genetic analysis and test for a wide variety of pathogens.”
The bottom line is that one of the mummies may have had the APC mutation, says the team, so the genetic predisposition to cancer may have existed before cellphones were invented. “We’ve found this mutation in only one individual so far," Dr. Sklan stresses. "Additional studies with a larger sample size should be conducted in order to draw more meaningful conclusions.”
The findings were published February 10, 2016, "Detection of a Tumor Suppressor Gene Variant Predisposing to Colorectal Cancer in an 18th Century Hungarian Mummy, in the journal Plos ONE. The researchers are in the process of establishing a specialized lab at Tel Aviv University to study ancient DNA.