Identification of Novel Alternative Transcripts of the Human ALKBH Gene Family and Investigation of Their Unique Expression Signatures in Cancer Cells

The human ALKBH gene family comprises nine Fe2+/α-ketoglutarate-dependent dioxygenases that catalyze the oxidative demethylation of DNA, RNA, and proteins, thereby influencing key cellular processes. Consequently, dysregulation of these enzymes has been implicated in various human diseases, particularly cancer. Although the transcriptomic profiles of certain members (e.g., ALKBH8, FTO) have been characterized, a comprehensive analysis of the entire ALKBH family remains unclear. In the present study, we investigated the alternative splice variants of the ALKBH genes through direct RNA sequencing across cancerous and non-cancerous cell lines. Novel splicing events were validated by NGS, while RT-qPCR was employed to assess transcript abundance and expression patterns. Additionally, in silico analysis was performed to predict the coding potential of the detected transcripts. Results: Bioinformatics analysis revealed previously uncharacterized alternative transcripts for the human ALKBH gene family members. Expression profiling demonstrated distinct expression patterns between cancerous and non-malignant cells, suggesting a potential role of these demethylases in tumor biology. The investigation of their coding capacity revealed that most of the newly detected transcripts were predicted to encode protein isoforms, highlighting the structural and predicted coding potential of the ALKBH family. Conclusions: Our findings provide the first comprehensive overview of the transcriptional diversity within the human ALKBH gene family. These results enhance our understanding of the demethylation mechanisms and their dysregulation in cancer.