Shigenobu Nagataki

15 years after Chernobyl: new evidence of thyroid cancer

The Chernobyl nuclear power plant accident happened on April 26, 1986. We investigated the cause of the striking increase in frequency of thyroid cancer in children who lived within a 150 km radius of Chernobyl and who were born before and after the accident. No thyroid cancer was seen in 9472 children born in 1987-89, whereas one and 31 thyroid cancers were recorded in 2409 children born April 27, 1986, to Dec 31, 1986, and 9720 born Jan 1, 1983, to April 26, 1986, respectively. Short-lived radioactive fallout caused by the Chernobyl accident probably induced thyroid cancer in children living near Chernobyl.

Gene Targeting to Hepatomas (AFP)

Hepatocellular carcinoma (HCC) is one of the most common malignancies with poor prognosis worldwide, especially in eastern Asia and Africa (1). Recent advances in delivering genes to mammalian cells stimulate the possibility of gene therapy for human diseases, including cancer gene therapy (2). One approach of gene therapy for cancers is the transduction of the herpes simplex virus thymidine kinase (HSV-tk) gene in tumor cells, because the killing effect of the HSV-tk product on the virus-infected cells is seen in only proliferating cells (3). HSV-tk can efficiently phosphorylate nucleoside analogs, and the phosphorylated products act as a chain terminator of DNA synthesis, leading to cell death (4). In addition, successful application of suicide gene therapy for cancer, in part, relies on the bystander effect, where the active chemotherapeutic agent produced in target cells diffuses from cells to neighboring malignant cells in sufficient concentrations to induce growth inhibition (5).