SP1 undergoes phase separation and activates RGS20 expression through super-enhancers to promote lung adenocarcinoma progression

Sep 21, 2026

Uploaded by Noah

Lung adenocarcinoma (LUAD) drives cancer-related mortality worldwide, yet its molecular drivers remain incompletely understood. This study shows that the transcription factor SP1 undergoes liquid–liquid phase separation, with zinc finger 3 essential for condensate formation. Using CUT&RUN with SP1 and H3K27ac antibodies, SP1 enrichment is linked to super-enhancer elements, identifying RGS20 as a key SP1-regulated target. SP1-driven RGS20 expression and malignant LUAD phenotypes are disrupted by the demethylase inhibitor GSK-J4, supporting an SP1–SE–phase separation mechanism for LUAD progression and therapy targeting.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages12

Reading Time30 min

AccessFree to download

Significance

SP1 condensation and LUAD phenotypes

CUT&RUN identification of RGS20

Role of GSK-J4 in disrupting SE-mediated activation

SP1 undergoes phase separation and activates RGS20 expression through super-enhancers to promote lung adenocarcinoma progression Liying Shana,1, Wenmeng Wangb,1, Lijuan Dua, Dangdang Lib , Yunxuan Wanga, Yuyan Xiea , Hongyan Lia, Jiale Wanga, Zhihao Shia, Yang Zhoua, Daling Zhuc, Guangchao Suib,2, and Fang Liua,2 Affiliations are included on p. 11. Edited by James Cleaver, University of California, San Francisco, CA; received January 28, 2024; accepted May 28, 2024 Lung adenocarcinoma (LUAD) is the leading cause of cancer-related death worldwide, but the underlying molecular mechanisms remain largely unclear. The transcription factor (TF) specificity protein 1 (SP1) plays a crucial role in the development ofvarious cancers, including LUAD. Recent studies have indicated that master TFs may form phase-separated macromolecular condensates to promote super-enhancer (SE) assembly and oncogene expression. In this study, we demonstrated that SP1 undergoes phase separation and that its zinc finger 3 in the DNA-binding domain is essential for this process. Through Cleavage Under Targets & Release Using Nuclease (CUT&RUN) using antibodies against SP1 and H3K27ac, we found a significant correlation between SP1 enrichment and SE elements, identified the regulator of the G protein signaling 20 (RGS20) gene as the most likely target regulated by SP1 through SE mechanisms, and verified this finding using different approaches. The oncogenic activity of SP1 relies on its phase separation ability and RGS20 gene activation, which can be abolished by glycogen synthase kinase J4 (GSK-J4), a demethylase inhibitor. Together, our findings provide evidence that SP1 regulates its target oncogene expression through phase separation and SE mechanisms, thereby promoting LUAD cell progression. This study also revealed an innovative target for LUAD therapies through intervening in SP1-mediated SE formation. SP1 | lung cancer | liquid–liquid phase separation | super-enhancer | RGS20 Lung cancer is a prevalent and deadly type of malignancy worldwide (1). Among the different subtypes of lung cancer, lung adenocarcinoma (LUAD) accounts for approximately 40% of lung cancer cases (2) . Despite recent advancements in targeted therapies and immunotherapies, the recurrence and metastasis of tumors continue to contribute to the low survival rates of lung cancer patients (3) . Hence, gaining a comprehensive understanding of the molecular mechanisms involved in the development and progression of LUAD is crucial for improving the diagnosis and treatment of this specific type of cancer. Cellular liquid–liquid phase separation (LLPS) refers to the formation of membraneless liquid phase compartments in eukaryotic cells through the aggregation of biological macromolecules such as nucleic acids and proteins (4) . This phenomenon plays a crucial role in various biological and pathological processes, including transcription, tumorigenesis, chromatin organization, the DNA damage response, ferroptosis, and autophagy. Researchers have demonstrated that LLPS can generate specialized condensates to carry out various functions (5–10). In 2017, Sharp and Young proposed the hypothesis that super-enhancers (SEs) are involved in gene regulation through a phase separation mechanism (11) . Subsequent investigations using advanced microscopic imaging corroborated the formation of phase separation aggregates at SEs, which could enrich or compartmentalize transcriptional coactivators at the chromatin loci of target genes. Many transcription factors (TFs) capable of undergoing phase separation contain intrinsically disordered regions (IDRs) that play crucial roles in the protein condensation process (12) . The cocondensation of master TFs with transcription mediators, coactivators, and other essential components of the transcriptional machinery can result in the assembly of SEs with the participation of many enhancer elements on chromatin and robustly activate downstream target

FAQs

What role does SP1 play in LUAD progression in this study?

SP1 undergoes phase separation and uses super-enhancer mechanisms to drive expression of the oncogenic target RGS20, promoting LUAD progression.

Which part of SP1 is essential for phase separation?

Zinc finger 3 in SP1’s DNA-binding domain is essential for SP1 condensation and for the associated malignant phenotypes of LUAD cells.

How was the SP1 target gene RGS20 identified?

CUT&RUN using antibodies against SP1 and the active histone mark H3K27ac revealed a correlation between SP1 enrichment and super-enhancer elements, with RGS20 identified as the most likely SE-regulated target.

Sep 21, 2026

Uploaded by Noah