Polr2b, also known as RNA polymerase II subunit B (RPB2), encodes the second largest subunit of RNA pol II. RNA polymerase II is crucial for transcribing DNA into messenger RNA, a fundamental process in gene expression, thus Polr2b is essential for normal cellular function and is involved in various biological pathways related to transcription regulation [2].

In glioblastoma, knockdown of Polr2b expression suppressed tumor cell growth both in vitro and in vivo, indicating its role as a growth regulator in this disease [2]. In glioma stem cells, a molecular network was discovered where m6A-methylated circPOLR2B forms an R-loop with its parental gene Polr2B. Changes in circPOLR2B levels affect the formation of R-loop structures, which in turn regulate Polr2B transcription and PBX1 expression through alternative polyadenylation, promoting the malignant biological behavior of glioma stem cells [1].

In summary, Polr2b is vital for transcription-related biological functions. Its study in glioblastoma and glioma stem cells, especially through knockdown experiments, reveals its significant role in tumor growth regulation. Understanding Polr2b's functions in these disease conditions may provide potential therapeutic targets for glioma treatment.

References:

1. Lin, Hongda, Cui, Zheng, E, Tiange, Liu, Libo, Xue, Yixue. 2024. M6A-methylated circPOLR2B forms an R-loop and regulates the biological behavior of glioma stem cells through positive feedback loops. In Cell death & disease, 15, 554. doi:10.1038/s41419-024-06946-6. https://pubmed.ncbi.nlm.nih.gov/39090090/

2. Li, Xiao-Lu, Xie, Yi, Chen, Yan-Ling, Li, Zhi-Heng, Pan, Jian. 2023. The RNA polymerase II subunit B (RPB2) functions as a growth regulator in human glioblastoma. In Biochemical and biophysical research communications, 674, 170-182. doi:10.1016/j.bbrc.2023.06.088. https://pubmed.ncbi.nlm.nih.gov/37423037/