Other highlights in the May 15 issue of JNCI

• Modified Adenoviral Therapy May Help Shrink Ovarian Tumors: The effectiveness of adenovirus-based gene therapy for advanced cancers has been limited because many cancer cells lack the receptor needed for viral infection. Using a modified adenoviral vector (RGDTKSSTR) that does not depend on the adenovirus receptor, Akseli Hemminki, M.D., Ph.D., of the University of Alabama at Birmingham, and his coworkers showed that mouse models of human ovarian cancer injected with this modified virus had smaller ovarian tumors and lived longer than mouse models injected with control viruses. The authors conclude that RGDTKSSTR may be a useful gene delivery tool for testing in ovarian cancer trials.

• Growth Factor May Be Associated with Decreased Lung Cancer Risk:Insulin-like growth factor I (IGF-I) stimulates cell growth in the lungs while its binding protein, IGF-binding protein 3 (IGFBP-3), inhibits cell growth. In a prospective study among men in China, Stephanie J. London, M.D., Dr.P.H., of the National Institute of Environmental Health Sciences, and her coworkers determined whether baseline serum levels of IGF-I and IGFBP-3 were associated with subsequent lung cancer risk.

  The authors compared serum levels of IGF-I and IGFBP-3 in 230 men who developed lung cancer during the course of the study and in 740 control subjects, and found that men with increased levels of IGFBP-3 at baseline had a reduced risk of lung cancer, whereas increased levels of IGF-I was not associated with increased lung cancer risk. The authors point out that the association was strongest in men with a smoking history.

• Environmental Factors May Influence Degree of DNA Methylation: Certain patterns of DNA methylation in tumor suppressor genes have been associated with cancer. One such pattern is the CpG island methylator phenotype (CIMP), which has been found in several cancers. Lanlan Shen and Jean-Pierre Issa, M.D., of the University of Texas M. D. Anderson Cancer Center in Houston, and their coworkers looked at gene methylation within hepatocellular carcinoma tumors from patients in different countries. The degree of methylation appeared higher in countries with a higher incidence of hepatocellular carcinoma. The authors suggest that environmental factors may influence the degree of methylation of multiple genes in hepatocellular carcinoma.

• Delivery of Antitumor Protein Enhanced With Electro-Gene Therapy: Interleukin-12 (IL-12) protein therapy has been shown to stimulate an antitumor response; however attempts to deliver the gene into tumors have not been very effective. Shulin Li, Ph.D., of the Henry Ford Health System in Detroit, Mich., and his coworkers used electric pulses to deliver the IL-12 gene into mouse tumor models and found that the treatment eradicated tumor growth in 40% of the mice, as well as triggered an immune response. Moreover, the antitumor memory lasted more than 11 months. The authors conclude that IL-12 electro-gene therapy could potentially be applicable in the treatment of electrode-accessible cancers, such as head and neck cancers.

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