Detection of genomically-tagged cancer cells in different tissues at different stages of tumor development: lack of correlation with the formation of metastasis

Functionality of Circulating DNA

“…3). It is noteworthy in this context that when rats are inoculated with DHD cells, either subcutaneously or by injection into the wall of the cecum, metastases always develop in the lungs 15. Also, we found the marker gene for CAT by PCR assays in blood and other tissues so that, in all 4 animals, at least 2 of the samples collected were positive.…”

“…We developed an experimental model of cancer using cells with a genome‐associated tag 15. In our model, tumors were transplanted in rats by subcutaneous injection of DHD cells that had been stably transfected with a plasmid that includes chloramphenicol acetyl transferase (CAT)‐encoding DNA sequences and a neomycin‐resistance gene.…”

“…To detect CAT‐encoding DNA sequences, we used a nested PCR technique that was designed to amplify such sequences 15. Using this method, we were able to obtain a 237‐base‐pair (237‐bp) product that was visible on a 2% agarose gel after electrophoresis and staining with ethidium bromide, with a starting concentration of 10 copies of the CAT DNA template in 200 μL of rat serum.…”

“…All samples were analyzed by PCR for CAT DNA. Assays were based on a published protocol 15. Samples from 2 uninjected control animals of similar age, which had been reared under the same conditions, were processed similarly and simultaneously.…”

Qualitative and quantitative characteristics of the extracellular DNA delivered to the nucleus of a living cell

“…The authors assumed that p53 protected the normal cells from replication of the transformed DNA upon cell engulfment of apoptotic bodies via activation of p21. Other researchers [ 8 , 9 ] proposed the term "genometastasis" and the corresponding working hypothesis as well as performed experiments that demonstrated the hypothesized transfer of oncogenes via blood plasma. And finally in the Yakubov's work [ 10 ] there was achieved the successful attempt of the reverse transformation of malignant into normal cells using the extracellular fragmented DNA that contained the full set of the genomic sequences.…”