Cytosine arabinoside-induced cytogenotoxicity in bone marrow and spermatogonial cells of mice and its potential transmission through the male germline.

Cytosine arabinoside (Ara-C), a widely prescribed antineoplastic drug, especially for the treatment of acute myeloid leukaemia, is a pyrimidine analog, in which the ribose sugar of cytidine is replaced by arabinose moiety. Ara-C reportedly competes with dCTP for incorporation into DNA during synthesis and exhibits various cytogenotoxic effects. In the present study, single intraperitoneal treatment of three different doses of Ara-C, 100, 150 and 200 mg/kg b.w. of mice, selected in accordance with its human therapeutic dose, induced statistically significant (p < or = 0.01) and dose dependent increase in the percentages of aberrant metaphases and chromosomal aberrations (CAs) at 24h post-treatment, and micronuclei (MN) in polychromatic erythrocytes (PCEs) at 30 h post-treatment. However, there was no significant change in the mitotic index (MI) at 24h post-treatment, when compared to that of the control mice. In the male germline, all the three doses of Ara-C induced statistically significant (p < or = 0.05 or p < or = 0.01) and dose dependent increase in the percentages of aberrant spermatogonial metaphases and CAs at 24h post-treatment and statistically significant (p < or = 0.01) and dose dependent increase in the percentages of aberrant primary spermatocytes at week 4 post-treatment. However, the induction of abnormal sperm at week 8 post-treatment was decreased, although significantly. The results indicated that Ara-C was clastogenic to both bone marrow and spermatogonial cells of mice, and some of its cytogenotoxic effects were found transmitted through the male germline, at least up to the formation of primary spermatocytes. As the drug is not target specific, the induced cytogenotoxic effects of Ara-C on non-cancerous cells of cancer patients retain possible risk of recurrence of second malignancy among the post-chemotherapeutic cancer survivors. In addition, there is every risk of transmission of some induced genetic alterations to the next generation through the gametes of the cancer survivors pre-treated with this drug. Therefore, Ara-C essentially be made target specific.