Increase of NAD glycohydrolase activity in uterine cervix cancers is caused by infiltration of lymphocytes

CD38 is a type II transmembrane glycoprotein which is expressed by hematopoietic and nonhematopoietic cells in human. It has two functions of ADP-ribosyl cyclase and cyclic ADP-ribose hydrolase activities and the sum of these two enzyme activities is identical with NAD glycohydrolase (NADase) activity. The levels of NADase activity in human cervical carcinoma and normal cancer tissue were measured. With a total of 12 patients with cervical cancer and 11 women with normal cervix, cancer tissues were found to have significantly higher NADase and ADP-ribosyl cyclase activities than the control group. Moreover, immunoblot analysis showed an increase of immunoreactivity against CD38 in cervical cancer tissues compared with normal tissues. Immunohistochemical data indicated that the increase of CD38 expression was due to increased infiltration of lymphocytes.