Eif5b, the eukaryotic translation initiation factor 5B, is a crucial factor in translational control, which occurs mainly at the translation initiation stage in eukaryotic cells. It tightly regulates global translation initiation and is involved in facilitating the expression of proteins related to processes like proliferation, apoptosis inhibition, and immunosuppression under stress conditions. It is associated with pathways related to cell survival and cancer progression [1].

In hepatocellular carcinoma (HCC), Eif5B was found to have significantly higher transcript, protein levels, and copy number in cancer tissues. Down-regulation of Eif5B decreased HCC cell proliferation, invasiveness, suppressed epithelial-mesenchymal transition and the cancer stem cell phenotype, and increased sensitivity to 5-fluorouracil. Also, in HCC cells, Eif5B silencing reduced NF-κB signaling pathway activation [2]. In prostate cancer, knocking down Eif5B inhibited cell proliferation, migration, invasion, and PD-L1 expression, promoted apoptosis, and increased vulnerability to peripheral blood mononuclear cells. Wig1 was shown to bind to Eif5B, and its overexpression had similar inhibitory effects on cancer cell behaviors [3].

In conclusion, Eif5B plays essential roles in regulating translation initiation and is involved in various biological processes related to cell survival and disease, especially in cancers like HCC and prostate cancer. Studies using gene knockdown models in these cancer cells have revealed its significance in promoting cancer cell progression, highlighting its potential as a biomarker and therapeutic target in these disease areas.

References:

1. Chukka, Prakash Amruth Raj, Wetmore, Stacey D, Thakor, Nehal. 2021. Established and Emerging Regulatory Roles of Eukaryotic Translation Initiation Factor 5B (eIF5B). In Frontiers in genetics, 12, 737433. doi:10.3389/fgene.2021.737433. https://pubmed.ncbi.nlm.nih.gov/34512736/

2. Li, Xiaoyin, Wang, Qian, Liang, Hongfeng, Lu, Yaoyong, Yang, Changfu. 2023. IGF2BP3-induced activation of EIF5B contributes to progression of hepatocellular carcinoma cells. In Oncology research, 30, 77-87. doi:10.32604/or.2022.026511. https://pubmed.ncbi.nlm.nih.gov/37305324/

3. Li, Qi, Xiao, Mulun, Shi, Yibo, Yan, Liang, Li, Xiaoyan. 2021. eIF5B regulates the expression of PD-L1 in prostate cancer cells by interacting with Wig1. In BMC cancer, 21, 1022. doi:10.1186/s12885-021-08749-w. https://pubmed.ncbi.nlm.nih.gov/34525951/