Radiobiology and reproduction-what can we learn from Mammalian females?

Analysis of nuclear maturation, DNA damage and repair gene expression of bovine oocyte and cumulus cells submitted to ionizing radiation

Radiotherapy causes destruction of tumor cells, but also threatens the integrity and survival of surrounding normal cells. Then, woman submitted to irradiation for cancer treatment may present permanent ovary damage, resulting in impaired fertility. The objective of this study was to investigate the effects of therapeutic doses of ionizing radiation (IR), used for ovarian cancer treatment in humans, on bovine cumulus-oocyte complexes (COCs) as experimental model. Bovine ovaries were exposed to 0.9 Gy, 1.8 Gy, 3.6 Gy or 18.6 Gy IR, and then COCs were collected and used to evaluate: (a) oocyte nuclear maturation; (b) presence of phosphorylated H2A.X (γH2AX), as an indicator of DNA double-strand breaks (DSBs); and (c) expression of genes involved in DNA repair (TP53BP1, RAD52, ATM, XRCC6 and XRCC5) and apoptosis (BAX). The radiation doses tested in this study had no detrimental effects on nuclear maturation and did not increase γH2AX in the oocytes. However, IR treatment altered the mRNA abundance of RAD52 (RAD52 homolog, DNA repair protein) and BAX (BCL2-associated X protein). We conclude that although IR doses had no apparent effect on oocyte nuclear maturation and DNA damage, molecular pathways involved in DNA repair and apoptosis were affected by IR exposure in cumulus cells.

Protective role of Aloe vera against X-ray induced testicular dysfunction

The present investigation was carried out to evaluate the possible radioprotective potential of an Aloe vera extract against whole-body X-ray irradiation-induced testicular alterations in mice. Male balb/c mice were divided into four groups: control, A. vera, X-ray and A. vera pre-treated + X-ray irradiated. Histopathological examination revealed significant structural alterations in testes after X-ray exposure, which was also associated with the presence of apoptotic cells as assessed by TUNEL assay. X-ray irradiation resulted in elevation in the levels of reactive oxygen species, lipid peroxidation, a reduction in glutathione concentration and enhanced activities of antioxidant enzymes such as glutathione reductase, glutathione peroxidase, catalase, superoxide dismutase and glutathione-S-transferase. Sperm count/motility and testosterone levels were significantly decreased in the irradiated group. Irradiated animals pre-treated with A. vera extract revealed an improvement in antioxidant status, inhibition of lipid peroxides, apoptotic cell formation and enhanced testicular parameters when compared to the X-ray-exposed group. These findings suggest that A. vera extract could ameliorate X-ray-induced damage due to its free radical scavenging properties and its potential to boost cellular antioxidant defence machinery.

Diminished Utilization of in Vitro Fertilization Following Ovarian Transposition in Cervical Cancer Patients

OBJECTIVE

To assess subsequent utilization of fertility treatment in reproductive-age women with cervical cancer (CC) who underwent ovarian transposition (OT) to preserve fertility prior to pelvic radiation.

STUDY DESIGN

This is a case series of 216 CC patients seen in a comprehensive cancer center. Sixteen patients underwent OT for fertility preservation prior to pelvic radiation. Patients were assessed for utilization of fertility treatment, follicle-stimulating hormone (FSH) levels as a measure of ovarian reserve, and functional assessment of chronic illness therapy-cervix cancer (FACT-CX) to assess quality of life after OT.

RESULTS

Of the patients, 94% of patients [corrected] maintained regular menstrual cycles 3 years after ovarian transposition (OT) [corrected] surgery (15/16). When measured (n = 5), serum FSH was normal at baseline and showed a transient elevation at 3 months following chemoradiation, with a return to normal levels at 6 months (means, 6.33 ± 2.94, 48.44 ± 18.63, and 12.52 ± 8.25 mIU/mL, respectively). Only 1 patient in this series attempted fertility treatment (in vitro fertilization) following OT, and she did not become pregnant. FACT-CX indicated that quality of life did not change significantly over the 6 months' duration following OT and chemoradiation therapy.

CONCLUSION

OT preserves menstrual cycle regularity without negatively impacting patients' quality of life. The utility of OT as an effective fertility preservation option is hampered by the low utilization rate of in vitro fertilization and lack of ovarian reserve assessment following OT.