BCL11A, also known as B-cell lymphoma/leukemia 11A, encodes a zinc-finger protein predominantly expressed in the brain and hematopoietic tissue. It functions mainly as a transcriptional repressor crucial in brain and hematopoietic system development, especially in the fetal-to-adult hemoglobin switching process. Genetic variations regulate its expression, and it is involved in multiple pathways related to hemoglobin regulation [4].

BCL11A is a key regulator in the fetal to adult hemoglobin switch. Genome-wide association studies (GWAS) identified its role in HbF regulation. In erythroid cells, its down-regulation can rescue the phenotype of engineered sickle cell disease (SCD) mice, suggesting its potential as a therapeutic target for SCD and β-thalassemia. Editing of the BCL11A enhancer in human progenitors and mouse transgenesis validates it as a target for HbF re-induction. Clinical trials using gene editing or post-transcriptional genetic silencing targeting BCL11A show promising results in treating SCD [1,2,3,5].

In conclusion, BCL11A is essential for the fetal-to-adult hemoglobin switch. Studies using mouse models and human cell-based experiments have revealed its role in hemoglobin-related diseases like SCD and β-thalassemia. These findings highlight its potential as a therapeutic target, offering new strategies for treating these severe monogenic diseases.

References:

1. Zheng, Ge, Orkin, Stuart H. . Transcriptional Repressor BCL11A in Erythroid Cells. In Advances in experimental medicine and biology, 1459, 199-215. doi:10.1007/978-3-031-62731-6_9. https://pubmed.ncbi.nlm.nih.gov/39017845/

2. Canver, Matthew C, Smith, Elenoe C, Sher, Falak, Orkin, Stuart H, Bauer, Daniel E. 2015. BCL11A enhancer dissection by Cas9-mediated in situ saturating mutagenesis. In Nature, 527, 192-7. doi:10.1038/nature15521. https://pubmed.ncbi.nlm.nih.gov/26375006/

3. Esrick, Erica B, Lehmann, Leslie E, Biffi, Alessandra, Manis, John P, Williams, David A. 2020. Post-Transcriptional Genetic Silencing of BCL11A to Treat Sickle Cell Disease. In The New England journal of medicine, 384, 205-215. doi:10.1056/NEJMoa2029392. https://pubmed.ncbi.nlm.nih.gov/33283990/

4. Yin, Jiawei, Xie, Xiaoli, Ye, Yufu, Wang, Lijuan, Che, Fengyuan. . BCL11A: a potential diagnostic biomarker and therapeutic target in human diseases. In Bioscience reports, 39, . doi:10.1042/BSR20190604. https://pubmed.ncbi.nlm.nih.gov/31654056/

5. Frangoul, Haydar, Altshuler, David, Cappellini, M Domenica, Yen, Angela, Corbacioglu, Selim. 2020. CRISPR-Cas9 Gene Editing for Sickle Cell Disease and β-Thalassemia. In The New England journal of medicine, 384, 252-260. doi:10.1056/NEJMoa2031054. https://pubmed.ncbi.nlm.nih.gov/33283989/