Expression of Forssman antigen synthesis and degradation in human lung cancer.

The activities of the two enzymes (UDP-acetylgalactosamine-globoside alpha-N-acetylgalactosaminyltransferase and alpha-N-acetyl-D-galactosaminidase) involved in the synthesis and degradation of Forssman antigen were studied in uninvolved and neoplastic human lungs. The Forssman synthetic enzyme activities of 17 of 18 squamous cell carcinomas were higher than those of the uninvolved lung tissues of the subjects studied, and the degradation enzyme activities of 16 of 18 squamous cell carcinomas were higher than those of the uninvolved portions. No consistent abnormalities in both enzyme activities were seen in 28 adenocarcinomas, whereas the mean activities of the two enzymes were elevated in these neoplasms. These differences in enzyme activities between those samples may indicate that the synthesis and degradation of Forssman antigen in adenocarcinoma of the lung are expressed or repressed according to the individual, whereas in squamous cell carcinoma, these activities are expressed unrelated to the individual.