Orosomucoid‐like 3 (ORMDL3) has been associated with asthma and a series of autoimmune disorders, and is involved in endoplasmic reticulum‐mediated inflammatory responses. However, its clinical significance and the molecular mechanism underlying its expression are still largely unclear. To elucidate the mechanisms of human ORMDL3 transcriptional regulation, we cloned a 1.5 kb genomic DNA fragment containing the putative promoter region and evaluated its transcriptional activity in a luciferase reporter system by deletion analysis. We identified a 68 bp region that functions as a minimal promoter. Bioinformatics analysis predicted that the −64 to −56 bp region contained a signal transducer and activator of transcription 6 (STAT6) binding site. Electrophoretic mobility shift assay and chromatin immunoprecipitation demonstrated that STAT6 bound to its binding site within the ORMDL3 promoter. STAT6 over‐expression or knockdown trans‐activated or trans‐inhibited, respectively, the ORMDL3 promoter containing the STAT6‐binding motif. Treatment with interleukins 4 or 13 increased ORMDL3 promoter activity as well as endogenous ORMDL3 expression. Immunoprecipitation and ChIP/Re‐ChIP assays revealed that STAT6 and p300 exist in the same protein complex that binds to the ORMDL3 promoter. Our study confirmed that STAT6 plays important roles in regulating the expression of human ORMDL3 by directly binding to the promoter region, which may shed light on a possible role in various human diseases.Structured digital p300 physically interacts with STAT6 by anti bait coimmunoprecipitation (View Interaction: 1, 2)
Purpose Mixed-lineage leukemia protein 4 (MLL4/KMT2D) is a histone methyltransferase, and its mutation has been reported to be associated with a poor prognosis in many cancers, including lung cancer. We investigated the function of MLL4 in lung carcinogenesis.Materials and Methods RNA sequencing (RNA-seq) in A549 cells transfected with control siRNA or MLL4 siRNA was performed. Also, we used EdU incorporation assay, colony formation assays, growth curve analysis, transwell invasion assays, immunohistochemical staining, and in vivo bioluminescence assay to investigate the function of MLL4 in lung carcinogenesis.Results We found that MLL4 expression was downregulated in non–small cell lung cancer (NSCLC) tissues compared to adjacent normal tissues and tended to decrease with disease stage progression. We analyzed the transcriptomes in control and MLL4- deficient cells using high-throughput RNA deep sequencing (RNA-seq) and identified a cohort of target genes, such as SOX2, ATF1, FOXP4, PIK3IP1, SIRT4, TENT5B, and LFNG, some of which are related to proliferation and metastasis. Our results showed that low expression of MLL4 promotes NSCLC cell proliferation and metastasis and is required for the maintenance of NSCLC stem cell properties.Conclusion Our findings identify an important role of MLL4 in lung carcinogenesis through transcriptional regulation of PIK3IP1, affecting the PI3K/AKT/SOX2 axis, and suggest that MLL4 could be a potential prognostic indicator and target for NSCLC therapy.
Hepatocellular carcinoma (HCC) is a leading global health concern, recognized for its complex pathogenesis and high mortality rates. The metastatic progression of HCC, considered the terminal event in tumor development, plays a pivotal role in determining patient prognosis, with metastasis being a key factor in poor survival outcomes.HDAC11 was found to be highly expressed in HCC tissues, with its elevated expression significantly correlating with poor patient survival. Both in vitro and in vivo experiments demonstrated that silencing HDAC11 led to a marked reduction in HCC cell proliferation. Interestingly, HDAC11 knockdown also resulted in a substantial increase in the metastatic potential of HCC cells. Mass spectrometry analysis revealed that HDAC11 interacts with the NuRD (MTA3) complex. Consistently, immunoprecipitation and GST pull-down assays demonstrated that the N-terminal region of HDAC11 directly binds to MTA3. Moreover, transcriptomic analysis indicated that HDAC11 represses TGFB1 transcription, thereby inhibiting HCC metastasis. The enhanced metastatic phenotype induced by HDAC11 silencing was reversed upon concurrent down-regulation of TGFB1. Moreover, nanoparticles encapsulating both HDAC11 and TGF-β1 inhibitors effectively suppressed HCC cell proliferation and metastasis. This research elucidates the molecular mechanism by which HDAC11 inhibits metastasis and provides an effective strategy to mitigate the side effects associated with HDAC11 inhibition, offering novel insights and approaches for the precision treatment of HCC.
Plant homeodomain (PHD) finger protein 20-like 1 (PHF20L1) is a novel epigenetic “reader” that specifically recognises histone post-translational modifications (PTMs) via its Tudor and PHD finger domains, thereby regulating chromatin remodelling, DNA damage repair, and oncogene transcriptional activation. This review comprehensively summarises the role of PHF20L1 in various cancers, including breast, ovarian, and colorectal cancers, as well as retinoblastomas, and elucidates its molecular mechanisms of action in cancer pathogenesis. Accumulating evidence indicates that PHF20L1 is upregulated in these malignancies and drives tumour progression by promoting proliferation, metastasis, and immune evasion. Furthermore, PHF20L1 orchestrates tumour-related gene expression by interacting with key epigenetic complexes. Given its unique structural features, we propose novel strategies for developing small-molecule inhibitors and combinatorial therapies, providing a theoretical basis for targeted epigenetic regulation for precision treatment. Future research should further investigate the molecular regulatory networks of PHF20L1 in different cancers and other human diseases and focus on developing specific small-molecule inhibitors to enable precision-targeted therapies.