I dont know how much stock to put into this particular paper, but some (potentially) incredible data just came out in Journal of Virology:
HERV-K (human endogenous retroviral family K) are the babies of human ERVs– they are the youngest addition to our genome (they became endogenous 200,000-5 million years ago), and related to a mouse retrovirus, MMTV.
These scientists did something kind of odd. They looked at patients that were healthy, had Rheumatoid Arthritis, HIV-associated lymphoma, non-HIV-associated lymphoma, HIV-associated Hodgkin lymphoma, or breast cancer, and just went fishing for ERVs floating around in their blood. Contrary to the claims of Creationists, who desperately want ERVs to be ‘functional’, normal people do NOT have retroviral particles derived from ERVs bopping around their bloodstream… but would cancer patients? Would they lose the ability to control their pirate DNA?
YUP! These scientists found em! ERVs, that are normally silent, were making detectable particles in lymphoma and breast cancer patients (not the healthy or arthritis patients). Cancer patients, for some reason, lost the ability to keep these bits of selfish DNA from carrying out their ultimate goal: replicate, spread.
These scientists used a few different methods to detect viral particles–
–They used PCR with several different kinds of HERV-K specific primers, and found ERV RNA in blood.
–They used RT assays to see if there was any reverse transcriptase in the blood.
–They did Western Blots to see if there was any Gag or Env protein in the blood.
–And they used electron microscopy to actually see viral particles in the blood!
They also assessed the level of ERV RNA in the blood pre- and post-cancer-treatment. Patients that went into remission had their ERV RNA levels drop below their detection limit, while patients who did not go into remission still have ERV RNA floating around!
Again, Im not sure what exactly to make of this data yet– I dont want to get too excited, but maybe these particles are actually infectious and are perpetuating/worsening the cancer. Maybe anti-retrovirals could act as anti-cancer agents! … but we dont know if thats the case, yet.
The authors do make the point that even if their observations are an artifact, even if these viral particles pop up, but they are harmless, detecting these little guys might still be useful as a relatively simple clinical tool! History of breast cancer in your family? Maybe you should get RT assays done on your blood, in addition to regular mammograms! Maybe the particles pop up before a mass is detectable! Undergoing treatment for lymphoma? Hey, your ERV RNA levels arent going down… maybe you should try a different anti-cancer drug.
Preliminary research, but they might be on to something!