Banp, also known as BTG3-associated nuclear protein, is a transcription factor with significant biological functions. It binds to the CGCG element and is a strong activator of CpG-island (CGI) regulated genes, controlling essential metabolic genes in pluripotent stem and neuronal cells [1]. DNA methylation of its binding motif repels its binding, epigenetically restricting binding to CGIs, and influencing gene regulation in cancer cells. Banp also has a role in cell-cycle related processes, acting as a tumor suppressor [2].

In zebrafish retina, Banp mutants show mitotic cell accumulation and apoptosis. DNA replication stress and tp53-dependent DNA damage responses are activated in these mutants, indicating Banp is required for DNA replication and damage repair. It directly regulates genes like wrnip1, cenpt, and ncapg which are involved in DNA replication stress recovery and chromosome segregation during mitosis [2]. In the context of cancer, knockdown of circular RNA circ-BANP inhibits the malignant progression of residual hepatocellular carcinoma after insufficient radiofrequency ablation by regulating the let-7f-5p/TLR4/STAT3 signaling pathway [3,4]. In lung cancer, silencing circ-BANP inhibits cell proliferation, migration, and invasion both in vitro and in vivo, as it acts as a sponge for miR-503 which targets LARP1 [5].

In summary, Banp plays crucial roles in gene activation, DNA damage response, chromosome segregation, and cell-cycle progression. Its dysregulation is associated with cancer development, as demonstrated through in vivo studies in zebrafish and in vitro and in vivo cancer models. Understanding Banp's functions provides insights into normal biological processes and potential cancer treatment strategies.

References:

1. Grand, Ralph S, Burger, Lukas, Gräwe, Cathrin, Vermeulen, Michiel, Schübeler, Dirk. 2021. BANP opens chromatin and activates CpG-island-regulated genes. In Nature, 596, 133-137. doi:10.1038/s41586-021-03689-8. https://pubmed.ncbi.nlm.nih.gov/34234345/

2. Babu, Swathy, Takeuchi, Yuki, Masai, Ichiro. 2022. Banp regulates DNA damage response and chromosome segregation during the cell cycle in zebrafish retina. In eLife, 11, . doi:10.7554/eLife.74611. https://pubmed.ncbi.nlm.nih.gov/35942692/

3. Li, Guoming, Kong, Jian, Dong, Shuying, Wu, Shilun, Sun, Wenbing. 2022. Circular BANP knockdown inhibits the malignant progression of residual hepatocellular carcinoma after insufficient radiofrequency ablation. In Chinese medical journal, , . doi:10.1097/cm9.00000000000001822. https://pubmed.ncbi.nlm.nih.gov/35941728/

4. Li, Guoming, Kong, Jian, Dong, Shuying, Wu, Shilun, Sun, Wenbing. 2022. Circular BANP knockdown inhibits the malignant progression of residual hepatocellular carcinoma after insufficient radiofrequency ablation. In Chinese medical journal, 135, 1578-87. doi:10.1097/CM9.0000000000001822. https://pubmed.ncbi.nlm.nih.gov/34985013/

5. Han, Jingquan, Zhao, Guibin, Ma, Xiao, Wang, Yue, Cui, Jian. 2018. CircRNA circ-BANP-mediated miR-503/LARP1 signaling contributes to lung cancer progression. In Biochemical and biophysical research communications, 503, 2429-2435. doi:10.1016/j.bbrc.2018.06.172. https://pubmed.ncbi.nlm.nih.gov/29969631/