Apoptosis in non-tumorous adult human testis tissue. Comparison of so-called 'normal' testis tissues

Apoptosis seems to play an important role in tumorigenesis, prognosis and therapy of testicular tumors. To understand its biological significance, it is important to quantify the amount of apoptosis and to compare the rate of apoptosis to that of a normal, unaffected reference tissue. Usually tissue from the unaffected site of the testis in patients with testicular cancer or testis tissue from patients who underwent surgical castration due to prostate cancer is used as the reference tissue. However it is not known, if both tissues are equivocal with respect to their apoptotic index. The purpose of the study was to compare the two most often used reference tissues for the quantification of apoptosis in testicular tissues with regard to their apoptotic index.

The apoptotic indices of both tissues were compared, using two standard apoptosis detection methods, i.e. in situ end labeling and a morphological approach.

The apoptotic index in testis tissue from patients who were surgically castrated for anti-hormonal treatment of prostate cancer was shown to be significantly higher than the apoptotic index of tumor free but tumor-associated testicular tissue of testis cancer patients. There was a strong relationship between the apoptotic index and the age of the patients.

Although there might be genetic changes in the tumor-associated testicular tissue influencing the apoptotic index, it seems advisable to use tumor-associated tissue rather than testis tissue of patients with prostate cancer as the reference tissue, due to the significant age dependence of the apoptotic index.