BAIAP2L2, also known as brain-specific angiogenesis inhibitor 1-associated protein like 2, is an important protein with diverse functions. It is involved in the maintenance of mechanotransducing stereocilia in cochlear hair cells [2,3,7]. In addition, it participates in various cancer-related processes, including promoting the malignancy of several cancers such as hepatocellular carcinoma (HCC), prostate cancer, osteosarcoma, and gastric cancer through different signaling pathways like VEGF, apoptosis, Wnt/β-catenin, AKT/mTOR [1,4,5,6].

In gene knockout studies, Baiap2l2 inactivation in mice causes degeneration of the mechanotransducing stereocilia in cochlear hair cells, leading to profound hearing loss, indicating its crucial role in maintaining the structure and function of cochlear hair cells [2,7]. In contrast, in vestibular hair cells, BAIAP2L2 inactivation does not affect stereocilia development or maintenance [3]. In cancer research, knockdown of BAIAP2L2 in cancer cell lines inhibits cell proliferation, migration, and invasion, and promotes apoptosis, highlighting its role in cancer progression [1,4,5,6].

In conclusion, BAIAP2L2 is essential for the maintenance of cochlear hair cell stereocilia and has a significant impact on cancer development. Gene knockout mouse models have been instrumental in revealing its role in hearing-related functions and in various cancer-associated processes, providing potential targets for treating hearing loss and cancers.

References:

1. Wei, Hui, Yang, Jing, Chen, Xia, Wang, Yuping, Zhou, Yongning. 2023. BAIAP2L2 is a novel prognostic biomarker related to migration and invasion of HCC and associated with cuprotosis. In Scientific reports, 13, 8692. doi:10.1038/s41598-023-35420-0. https://pubmed.ncbi.nlm.nih.gov/37248248/

2. Yan, Keji, Zong, Wen, Du, Haibo, Wang, Yanfei, Xu, Zhigang. 2021. BAIAP2L2 is required for the maintenance of mechanotransducing stereocilia of cochlear hair cells. In Journal of cellular physiology, 237, 774-788. doi:10.1002/jcp.30545. https://pubmed.ncbi.nlm.nih.gov/34346063/

3. Yan, Keji, Qu, Chengli, Wang, Yanfei, Zong, Wen, Xu, Zhigang. 2022. BAIAP2L2 Inactivation Does Not Affect Stereocilia Development or Maintenance in Vestibular Hair Cells. In Frontiers in molecular neuroscience, 15, 829204. doi:10.3389/fnmol.2022.829204. https://pubmed.ncbi.nlm.nih.gov/35242013/

4. Song, Yuanzi, Zhuang, Guishan, Li, Jiazhen, Zhang, Mingqing. 2021. BAIAP2L2 facilitates the malignancy of prostate cancer (PCa) via VEGF and apoptosis signaling pathways. In Genes & genomics, 43, 421-432. doi:10.1007/s13258-021-01061-8. https://pubmed.ncbi.nlm.nih.gov/33646530/

5. Guo, Hongting, Peng, Jing, Hu, Juan, Tang, Haiping, Chen, Youhao. 2021. BAIAP2L2 promotes the proliferation, migration and invasion of osteosarcoma associated with the Wnt/β-catenin pathway. In Journal of bone oncology, 31, 100393. doi:10.1016/j.jbo.2021.100393. https://pubmed.ncbi.nlm.nih.gov/34786330/

6. Liu, Jianing, Shangguan, Yumeng, Sun, Jingfu, Cong, Wei, Xie, Yuxiang. 2020. BAIAP2L2 promotes the progression of gastric cancer via AKT/mTOR and Wnt3a/β-catenin signaling pathways. In Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie, 129, 110414. doi:10.1016/j.biopha.2020.110414. https://pubmed.ncbi.nlm.nih.gov/32570120/

7. Carlton, Adam J, Halford, Julia, Underhill, Anna, Barr-Gillespie, Peter G, Marcotti, Walter. 2020. Loss of Baiap2l2 destabilizes the transducing stereocilia of cochlear hair cells and leads to deafness. In The Journal of physiology, 599, 1173-1198. doi:10.1113/JP280670. https://pubmed.ncbi.nlm.nih.gov/33151556/