This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Koprowski, H. Articles by Koprowska, I. Search for Related Content PubMed PubMed Citation Articles by Koprowski, H. Articles by Koprowska, I.

Neoplastic Transformation¹

The Wistar Institute of Anatomy and Biology, and Hahnemann Medical College (I. K.), Philadelphia, Pennsylvania

"Scientific controversies constantly resolve themselves into differences about the meaning of words" (Schuster, cited in Ref. 18). The meaning of the word "transformation" has plagued scientists for quite some time since it apparently means one thing to bacterial geneticists and another thing to oncologists. It is proposed in this review to use the term "conversion" for description of events which take place within a defined set of circumstances after animal cells have been exposed to tumor virus. These events can then be observed at the single cell level. It is further proposed that the term "transformation" be applied to the other types of tumor-virus-animal cell interactions, with the understanding that these interactions can be described only at cell population levels and that many events associated with transformation may occur sporadically; thus, they cannot be observed with the precision that is characteristic of the "conversion" phenomenon. Various criteria proposed for "neoplastic transformation" are examined in light of experimental facts and realities.

¹ This work was supported, in part, by USPHS Research Grant CA-04534 and contract PH-43-62-157 from the National Cancer Institute, and the American Cancer Society, Grant E-89 and USPHS Grant C-Y-3654.