Results of a pilot study suggest safe transplantation of spermatogonial stem cells (SSCs) may be possible, potentially bringing us one step closer to ensuring fertility preservation in young boys with cancer.
Investigators found they could culture a large amount of SSCs using testicular tissue from boys with acute lymphoblastic leukemia (ALL).
And the ALL cells did not survive the culture process.
The researchers reported these results in Fertility and Sterility.
“Our study addressed an important safety issue—whether cancer cells that might be present in testicular tissue samples can survive the process to replicate the sperm-producing stem cells,” said study author Hooman Sadri-Ardekani, MD, PhD, of Wake Forest Baptist Medical Center in Winston-Salem, North Carolina.
“This is an important consideration because of the potential to re-introduce cancer into the patient. The research, which involved one of the most common childhood cancers, shows that the cancer cells were eliminated. Based on these findings, we recommend that all boys with cancer be offered the option of storing testicular tissue for possible future clinical use.”
Previous research had shown that up to 30% of boys with ALL had cancer cells in their testicular tissue. In several studies, researchers attempted to eliminate cancer cells from biopsy tissue, but the results varied.
So Dr Sadri-Ardekani and his colleagues decided to investigate whether cancer cells would survive the protocol they had developed to reproduce SSCs from a small tissue biopsy.
This process multiplies the original SSCs by 18,000-fold so there are enough cells to transplant back into the patient when he reaches adulthood.
The investigators tested the method using samples from 3 ALL patients. The team cultured the ALL cells alone and at various concentrations in combination with testicular cells.
The ALL cells cultured alone did not survive beyond 14 days. But the testicular cells cultured in parallel survived and continue to proliferate well after 8 weeks.
At 10 to 16 days, the ALL cells cultured in combination had begun to die off. The cells were undetectable in cultures from 2 of the patients that had an initial ALL concentration of 0.04%, 0.4%, or 4%.
At 20 to 26 days, ALL cells were undetectable in all cultures, even those with an initial concentration of 40% ALL cells.
“This pilot study showed that the culture system not only allowed for efficient propagation of sperm stem cells but also eliminated ALL cells,” Dr Sadri-Ardekani said.
SSC transplants have not yet been attempted in humans, but they have been performed successfully in several species of animals, including monkeys.
Dr Sadri-Ardekani noted that before we can perform SSC transplants in patients, additional research is needed, particularly, research investigating whether other types of leukemia cells will also be eliminated in the cell-propagation process.
