It may be possible to protect the testes of cancer patients against the loss of fertility caused by chemotherapy, a scientist told the 22nd annual conference of the European Society of Human Reproduction and Embryology in Prague, Czech Republic.

Mr. Alon Carmely from Bar-Ilan University, Ramat Gan, Israel, said that his work showed for the first time that the injection of a drug that enhances the immune system could protect the testis from the effects of paclitaxel (Taxol), a widely used chemotherapy drug.

“The effects of chemotherapy treatment on fertility are an important issue for long-term survivors of cancer who may not have started or completed a family at the time of diagnosis”, said Mr. Carmely. “AS101 is a Tellurium-based non-toxic immunomodulatory compound developed and synthesised by us. Tellurium is a transition element with similar properties to Selenium, which is also known to have many beneficial effects.”

Knowing that AS101 had been shown to have chemoprotective effects in both animal and human studies, he and his team decided to investigate whether it could be used to avoid testicular damage in mice treated with Taxol. “Clinical studies had already shown that AS101 could protect against bone marrow damage and hair loss, and also sensitises the tumour to treatment”, he said.

The scientists divided the mice into four groups - Taxol only, AS101 plus Taxol, AS101 only, and a control group. After 30 days they were euthanized and their testes examined and weighed. The researchers found that a single dose of Taxol had induced significant testicular weight loss compared with the control group. An injection of AS101 a day before that of Taxol prevented the Taxol-induced weight loss.

“Tissue analysis of the testes of Taxol-injected mice showed severe atrophy and empty seminiferous tubules, where the sperm-producing cells are contained”, said Mr. Carmely. “In contrast, we saw only minimal testicular damage in the group that had previously been injected with AS101, and we could also find mature sperm. Injection of AS101 alone did not alter testicular weight or tissue analysis results.

“These results hold out much promise for fertility preservation in men undergoing cancer treatments”, he said. “We now intend to study the mechanism of protection, which is still unclear. Our work suggests that in addition to the direct damage caused by the treatment, significant testicular damage is caused by the immune reaction to it. We hope to begin clinical studies in cancer patients in the next few months.”

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European Society of Human Reproduction and Embryology