Global 3'UTR shortening and down-regulation of repeated element related piRNA play crucial roles in boys with cryptorchidism

Background: Cryptorchidism is the most common congenital defect in children's genitourinary system. Decades of research have identified both environmental and genetic factors contribute to the etiology.

Methods: Small-RNA/mRNA-seq were performed on testicular tissues from cryptorchidism patients. Downstream analysis included mRNA expression, piRNA expression and miRNA expression.

Results: We find a global downregulation of repeated element related piRNA expression as well as a global 3'UTR shortening of mRNAs in patients with cryptorchidism. We also find that genes with shortened 3'UTR which are highly enriched in vascular endothelial growth and protein ubiquitination, tend to be up-regulated in cryptorchidism. These results indicate that boys with cryptorchidism may not have normal piRNA functions to protect developmental tissues from transposon invasion. Dysregulated shortened 3'UTR genes may affect normal testicular tissue development.

Conclusion: In summary, our findings also provided the first landscape of gene regulation in cryptorchidism, especially in terms of post-transcriptional regulations.