Dip2c, a vertebrate homologue of the Drosophila disconnected (disco)-interacting protein 2 (DIP2) gene, contains a DNA methyltransferase-associated protein 1 (DMAP1) binding domain, Acyl-CoA synthetase domain and AMP-binding sites. It is highly conserved and widely expressed in the central nervous system. Although its exact function is not fully understood, it may be involved in regulating axonal development as seen in Drosophila and C. elegans homologues [1].

In a study of 23 individuals with heterozygous DIP2C variants, most manifested developmental delays mainly affecting expressive language and speech articulation. Eight had de novo loss-of-function variants, two had de novo missense variants, and others had inherited loss-of-function variants. Some also had cardiac defects and minor facial anomalies. Brainspan analysis showed elevated DIP2C expression in the human neocortex at 10-24 weeks after conception, suggesting its role in neurocognitive development [1]. A 17-month-old infant with focal infantile epilepsy was found to have a de novo single-nucleotide variation in DIP2C that led to alternative splicing, providing a new candidate gene for this disorder [2]. SNPs of DIP2C were associated with autism spectrum disorder (ASD) susceptibility in a Chinese Han case-control study, and some SNPs were related to “visual reaction” phenotypes of ASD [3]. In murine ES cells, Dip2c -/- cell lines generated by Nuclease technology were used to study its function during early embryo development [4]. In breast cancer, DIP2C expression was lower, especially in basal-like and HER-2 subtypes, and was correlated with ER, PR, and EGFR expressions [5]. In prostate cancer, exosomal miR-375 targeted DIP2C, activated the Wnt signaling pathway, and promoted osteoblastic metastasis and cancer progression [6]. In RKO cells, knockout of DIP2C led to cell enlargement, growth retardation, changes in DNA methylation, and epithelial-mesenchymal transition [7].

In conclusion, Dip2c appears to play crucial roles in neurocognitive development, as evidenced by its association with expressive speech delay, focal infantile epilepsy, and ASD. It is also involved in cancer-related processes such as breast and prostate cancer development, and metastasis, as well as epithelial-mesenchymal transition in cancer cells. The generation of Dip2c knockout models in mice and cells has been valuable for understanding its functions in these biological processes and disease conditions.

References:

1. Ha, Thoa, Morgan, Angela, Bartos, Meghan N, Voineagu, Irina, Slavotinek, Anne. 2024. De novo variants predicting haploinsufficiency for DIP2C are associated with expressive speech delay. In American journal of medical genetics. Part A, 194, e63559. doi:10.1002/ajmg.a.63559. https://pubmed.ncbi.nlm.nih.gov/38421105/

2. Yang, Le, Zhao, Siyu, Ma, Nan, Wang, Yan, Wang, Dong. 2021. Novel DIP2C gene splicing variant in an individual with focal infantile epilepsy. In American journal of medical genetics. Part A, 188, 210-215. doi:10.1002/ajmg.a.62524. https://pubmed.ncbi.nlm.nih.gov/34617658/

3. Li, Yan, Sun, Chuanyong, Guo, Yanbo, Cheng, Yi, Liu, Yawen. 2022. DIP2C polymorphisms are implicated in susceptibility and clinical phenotypes of autism spectrum disorder. In Psychiatry research, 316, 114792. doi:10.1016/j.psychres.2022.114792. https://pubmed.ncbi.nlm.nih.gov/35987071/

4. Yao, Mingze, Su, Pengfei, Li, Zhengfeng, Zheng, Yaowu, Wu, Changxin. 2021. Knockout of Dip2c in murine ES cell line IBMSe001-B-1 by Nuclease technology genome editing technology. In Stem cell research, 53, 102236. doi:10.1016/j.scr.2021.102236. https://pubmed.ncbi.nlm.nih.gov/33813174/

5. Li, Jing, Ping, Jin Liang, Ma, Bo, Chen, Ying Rong, Li, Li Qin. 2017. DIP2C expression in breast cancer and its clinical significance. In Pathology, research and practice, 213, 1394-1399. doi:10.1016/j.prp.2017.09.007. https://pubmed.ncbi.nlm.nih.gov/28964575/

6. Liu, Ying, Yang, Changmou, Chen, Shisheng, He, Shuhua, Hui, Jialiang. 2022. Cancer-derived exosomal miR-375 targets DIP2C and promotes osteoblastic metastasis and prostate cancer progression by regulating the Wnt signaling pathway. In Cancer gene therapy, 30, 437-449. doi:10.1038/s41417-022-00563-1. https://pubmed.ncbi.nlm.nih.gov/36434177/

7. Larsson, Chatarina, Ali, Muhammad Akhtar, Pandzic, Tatjana, He, Liqun, Sjöblom, Tobias. 2017. Loss of DIP2C in RKO cells stimulates changes in DNA methylation and epithelial-mesenchymal transition. In BMC cancer, 17, 487. doi:10.1186/s12885-017-3472-5. https://pubmed.ncbi.nlm.nih.gov/28716088/