PROGRAM AREA REPORTS

CANCER VIROLOGY PROGRAM

During this two year period, the Cancer Virology Program Area completed a survey of the general field of cancer virology and began a concentration on specific topics of mutual interest and importance to scientists in both Japan and the U.S.
Two symposia were held during this period. The first symposium was on “Viral Oncogenesis: Transmission, Persistence, and Expression of Viral Genome.” The participants reported work covering the entire spectrum of cancer virology, on culture of human cancer cells, and on possible interrelationships of chemical and viral carcinogenesis. The newest data were presented on the major groups of cancer viruses: papovaviruses, adenoviruses, herpes viruses, and type C tumor viruses. These presentations ranged from basic molecular virology to implications of cancer in wild mice, including human cancer and a description of type C viruses recovered from human acute myelocytic leukemia cells. The second symposium, “Origin and Function of Oncogenic Sequences in RNA Tumor Viruses,” dealt with current research in both countries on the rapidly expanding field of RNA tumor viruses. Extensive discussions of endogenous viruses and virus-like genomes were presented. The differences and similarities in virus-host cell systems currently under study in the U.S. and Japan were extensively analyzed. The relationship of gene sequences to cellular transformation and differentiation was explored.
As a result of these symposia where much unpublished ongoing work was presented by scientists from both sides, an active exchange of visiting scientists occurred. Several Japanese scientists have presented their data at the Cold Spring Harbor Symposia. Thirteen scientists spent periods of several weeks to three months working in host laboratories and presenting seminar series on their own work. Important collaborative efforts undertaken as a result of these exchange visits have included work on papovaviruses and the heteroduplex mapping technique for nucleic acids.
Courses on electron microscopic visualization of viral sequences and in situ hybridization on blotting paper of gel-spread DNA fragments were prepared by two active U.S. viral oncologists and were enthusiastically appreciated by the Japanese participants. Also, as a direct result of the exchange visits and symposia, two independent meetings on Epstein-Barr virus and Friend leukemia virus were held in Japan which included a number of American scientists. These meetings fostered a series of collaborative and cooperative exchanges beyond the direct participants in the U.S.-Japan Cooperative Cancer Research Program.
Because of the critical nature of reagents, viruses, and cell lines to comparability and reproducibility of research in this program area, the exchange of materials and resources has played a significant part in the program area’s efforts.
Information on sources and applications of high-quality restriction enzymes was helpful in expanding the scope of techniques in collaborating laboratories. Five hundred units of highly purified erythropoietin was sent from the U.S. to Japan for use in experiments on induction of differentiation of Friend virus-induced leukemia cells. Avian myeloblastosis virions and antisera to type C viruses were provided for studies of possible viral etiology in human cancers. The 3Y-1 rat cell line was sent from Japan to the U.S. for work on viral transformation. Current plans call for future exchanges of materials and resources including AMV reverse transcriptase, SFP Iaboratory animals, and several cultured cell lines.
Future plans for the Cancer Virology Program Area emphasize the continued active exchange of both personnel and materials. This double-pronged exchange will promote thorough familiarity with the work being done in the best laboratories in both the U.S. and Japan. The next scientific meeting on DNA tumor viruses is expected to foster an even more active series of collaborative exchanges in this second large area of interest in viral oncology.