Plicamycin (PLI) is a small-molecule aureolic acid antibiotic that has been approved for cancer treatment since the 1970s. However, its interaction with cardiovascular biological systems during myocardial ischemia-reperfusion injury (MIRI) remains largely unknown. This study examines its cardioprotective effects and the mechanisms associated with cAMP response element-binding protein (CREB) and brain-derived neurotrophic factor (BDNF) in a murine MIRI model. PLI, administered intraperitoneally to mice at 150 μg/kg/day for seven days before cardiac ischemia-reperfusion, attenuated the rise in myocardial infarct size and serum creatine kinase (CK) and lactate dehydrogenase (LDH) levels. PLI also improved cardiac function in MIRI mice, as reflected by higher ejection fraction (EF) and fractional shortening (FS) values. Biochemical assays and dihydroethidium (DHE) staining analyses showed that PLI administration prevented oxidative stress imbalance within the ischemic myocardium following reperfusion. PLI also prevented cardiomyocyte apoptosis within ischemic myocardial tissues by downregulating caspase-3, caspase-9, and Bax and upregulating Bcl-2 expression in MIRI mice. Further investigation showed that I/R injury reduced the expression levels of phospho-CREB and BDNF within the ischemic myocardium, both of which were prevented by PLI. More importantly, pharmacological suppression of CREB by 666-15 (10 mg/kg/day) or BDNF signaling by K252a (25 μg/kg/day) diminished the cardioprotective effects of PLI. Overall, our data suggest that PLI prevents I/R-induced cardiac injury by activating CREB-BDNF signaling, accompanied by suppression of nitro-oxidative stress.

TP53 abnormalities contribute to treatment resistance and poor prognosis in multiple myeloma (MM), yet their functional consequences remain unclear. Here, we integrate ex vivo drug sensitivity profiling, genomics, transcriptomics, and proteomics across 167 CD138[+] bone marrow patient samples to characterize TP53-associated vulnerabilities. Genome-wide CRISPR-Cas9 and RNAi screening identify vulnerabilities in TP53-mutated MM, with or without del(17p), highlighting the dependency on spindle organization, mitotic regulation, DNA synthesis, and transcriptional and metabolic regulation, but independence from MDM2. CD138[+] cells with TP53 mutation exhibit increased sensitivity to chemotherapeutics, HDAC, HSP90, IGF1R, and PI3K/AKT/mTOR inhibitors as well as RNA synthesis inhibitor plicamycin, with distinct drug response profiles of MM with del(17p) and WT TP53. Our study provides new insights into refining TP53 classification to optimize treatment strategies for high-risk MM.

In brief: The preimplantation embryonic development progress is accompanied by dynamic changes of transcriptome, and many transcription factors have been found to responsible for this progress. This study shows that SP1 is necessary for proper zygotic genome activation and morula-to-blastocyst transition by regulating transcriptome establishment and histone modifications in mouse preimplantation embryos. Abstract: Specificity protein 1 (SP1) is the most active member of the specificity protein and Krüppel-like factor (Sp/KLF) family and is widely expressed across all mammalian cell types. However, more detailed studies on the role of SP1 in preimplantation embryonic development are needed. Here, we analyzed the role of SP1 in the development of preimplantation mouse embryos through supplementation with a small molecular inhibitor (plicamycin) and microinjection of Sp1 siRNA. We found that SP1 was indispensable for zygotic genome activation (ZGA) and the morula-to-blastocyst transition. Plicamycin supplementation arrested embryo development at the 2-cell stage and resulted in aberrant RNA polymerase II preconfiguration. Sp1 expression knockdown by Sp1 siRNA microinjection caused most embryos to arrest at the morula stage, and the expression of NANOG, POU5F1, and CDX2 significantly decreased. Both plicamycin supplementation and Sp1 siRNA microinjection decreased embryonic H3K4me3 levels and increased H3K9me3 levels. Moreover, when Sp1 was overexpressed, the embryos were arrested at the 2-cell stage, the H3K4me3 level increased, and the H3K9me3 level decreased. In conclusion, our findings demonstrate that SP1 is crucial for mouse preimplantation embryonic development through the regulation of gene expression and histone modifications.

Postovulatory oocyte aging (POA) is a key factor contributing to the decline in female fertility and the success rate of assisted reproductive technology. Currently, most studies on POA have focused on downstream phenotypes such as mitochondrial dysfunction and oxidative stress, while little is known about its key upstream regulatory factors. Here, we show that the downregulation of transcription factor Early Growth Response 1 (EGR1) is a key upstream event driving porcine oocyte aging. Microtranscriptome sequencing combined with experimental validation verified a notable reduction in EGR1 protein abundance in aged oocytes. We found that Ursodeoxycholic Acid (UDCA) upregulated EGR1, which in turn promoted the expression of the autophagy-related protein LC3B and the lysosomal protein LAMP1, while reducing P62 accumulation. Furthermore, UDCA enhanced the expression of mitophagy core proteins PINK1, VDAC1 and promoted mitochondrial-lysosomal colocalization, thereby improving mitophagy and restoring the quality of aged oocytes. Crucially, treatment with the EGR1 inhibitor plicamycin completely blocked UDCA's ability to enhance the developmental potential of aged oocytes, confirming that EGR1-mediated mitophagy was the core pathway underlying UDCA's effects. Collectively, this study innovatively identified EGR1 as a key bridge linking oocyte aging and decreased mitophagy, and clarified the novel mechanism by which UDCA exerts its protective effects through the "UDCA-EGR1-mitophagy" axis. Our findings advanced the research on oocyte aging from phenotypic observation to the upstream transcriptional regulation level, providing a novel theoretical target and experimental basis for fundamentally intervening in reproductive aging.

Metabolic reprogramming is a hallmark of cancer, yet the critical drivers and mechanisms in hepatocellular carcinoma (HCC) remain incompletely understood. Through a metabolism-focused CRISPR screen, we identified phosphomevalonate kinase (PMVK), a mevalonate pathway enzyme, as a key regulator of HCC stemness and progression. PMVK directly phosphorylates the transcription factor SP1 at Thr[355], which enhances SP1's DNA binding affinity and promotes its interaction with the master lipid regulator SREBP1/2, driving a transcriptional program essential for de novo cholesterol and fatty acid synthesis. Clinically, PMVK levels are positively correlated with phospho-SP1 (Thr[355]) levels and predicate poor prognosis in patients with HCC. Functionally, we demonstrate that genetic or pharmacologic inhibition of the PMVK-SP1 axis, including using the SP1 inhibitor mithramycin A (MTA), significantly suppresses HCC tumorigenesis. In conclusion, our findings uncover the PMVK-SP1 axis as a central driver of lipid metabolic reprogramming and hepatocarcinogenesis, highlighting it as a compelling therapeutic target in HCC.

Hepatocellular carcinoma (HCC) is a highly heterogeneous malignancy characterized by poor prognosis and limited therapeutic response. Cancer stem cells (CSCs) contribute to tumor progression, therapeutic resistance, and tumor recurrence. Among transcriptional regulators potentially involved in these processes, Specificity Protein 1 (SP1) has emerged as a candidate integrator of oncogenic and epigenetic signaling networks. However, its contribution to CSC-associated phenotypes and drug resistance in HCC remains incompletely defined. In this study, we combined transcriptomic analyses of TCGA datasets with functional experiments in HCC cell lines (Huh7 and HepG2). SP1-associated transcriptional programs were targeted pharmacologically using mithramycin A (MIT-A) and genetically using siRNA-mediated knockdown. The effects were assessed by RNA sequencing, RT-qPCR, Western blotting, flow cytometry, and functional assays evaluating proliferation, migration, CSC-associated properties, and response to sorafenib. MIT-A treatment markedly reduced the expression of stemness-associated transcription factors (NANOG, OCT4, SOX2) and CSC markers (CD133, CD24), impaired CSC-related functions including ALDH activity and the Side Population phenotype, and inhibited cell proliferation and migration. MIT-A also sensitized both parental and sorafenib-resistant HCC cells to sorafenib, associated with modulation of apoptotic regulators and reduced transporter-mediated efflux activity. SP1 knockdown partially reproduced several of these effects, supporting a contribution of SP1-dependent transcriptional programs to these phenotypes. Overall, these findings identify SP1-associated transcriptional networks as potential regulators of CSC features and therapeutic resistance in HCC and support targeting SP1-associated transcriptional programs as a strategy to enhance sorafenib efficacy.

Solitary fibrous tumor (SFT) is a rare and aggressive sarcoma driven by NAB2::STAT6 gene fusions, yet effective targeted therapies remain unavailable. Here, we report that the NAB2ex4::STAT6ex2 fusion variant forms nuclear condensates via liquid-liquid phase separation (LLPS) in engineered fibroblast models and primary SFT cells. These condensates co-localize with BRD4S and EGR1, key transcriptional regulators, and are functionally active, driving widespread transcriptional reprogramming. Treatment with Mithramycin A, a compound that disrupts EGR1-DNA interactions, dissolves NAB2::STAT6 condensates and reverses their aberrant gene expression and chromatin binding signatures. Our findings uncover a previously unrecognized role for NAB2::STAT6 in condensate-mediated oncogenic signaling and provide a mechanistic rationale for condensate-targeted therapy in SFT.

Hyperthermic intraperitoneal chemotherapy (HIPEC) for colorectal peritoneal metastases relies primarily on DNA-damaging agents whose efficacy depends on sustained cytotoxic exposure. Whether brief treatment can induce durable transcriptional remodeling remains unclear. Mithramycin A (MA) is a GC-rich DNA-binding agent with transcriptional regulatory activity involving chromatin-associated pathways. Here, we investigated the molecular and functional consequences of a single 90-min HIPEC-mimetic MA exposure in colorectal cancer models. RNA sequencing revealed extensive and coordinated transcriptional remodeling, affecting a substantial fraction of expressed genes and producing a response qualitatively distinct from mitomycin C. MA selectively suppressed key chromatin-associated regulatory factors, including DNMT1, JARID2, and HDAC4, while coordinately activating canonical cyclin-dependent kinase inhibitors CDKN1A, CDKN1C, and CDKN2C. Gene set enrichment analysis demonstrated enrichment of G2/M checkpoint pathways and suppression of oncogenic gene networks. These molecular changes translated into sustained inhibition of clonogenic growth and activation of caspase-dependent apoptosis following drug washout, with hyperthermia potentiating apoptotic signaling. Collectively, these findings indicate that brief MA exposure induces selective modulation of chromatin regulators and durable transcriptional reorganization, supporting modulation of chromatin regulatory networks as a potential therapeutic strategy for HIPEC-based colorectal cancer therapy.

Linker histone H1.2 (H1.2), as a member of the histone H1 family involved in many cellular physiological regulatory functions, plays a vital role in maintaining nucleosome and chromatin stability. Cyclic GMP-AMP synthase (cGAS) is a critical cytoplasmic DNA sensor that activates the downstream STING pathway by synthesizing 2'3'-cGAMP, which, in turn, triggers IFN-I response following double-stranded DNA virus infection. This study demonstrates that histone H1.2 is an essential negative regulator of cGAS, inhibiting antiviral immunity during HSV-1 infection. Mechanistically, H1.2 affects the activity of the Lys240 site of cGAS to affect the combination of cGAS with chromatin and promotes the degradation of cGAS in the nucleus by recruiting TRIM28, finally suppressing its IFN response. Moreover, HSV-1 infection downregulates H1.2 expression by reducing the mRNA levels of its transcription factor Sp1, thus allowing cGAS release to activate type I interferon signaling. Additionally, plicamycin, a selective inhibitor of Sp1, can reduce H1.2 expression and enhance antiviral immunity in mice against HSV-1 infection. These findings elucidate the function and regulatory mechanisms of the Sp1-H1.2-cGAS axis in innate immunity and propose new targets and strategies for antiviral drug development.IMPORTANCEPrevious studies on histone H1.2 mainly focused on its function of DNA damage repair and chromatin stability. However, our research found the new function and mechanism of H1.2 in anti-infection immune regulation and confirmed H1.2 as an important negative regulatory molecule responsible for inhibition of cGAS, the important sensor in pathogenic recognition. In the nucleus, H1.2 maintained the inactive state of cGAS by promoting its combination to chromatin and recruiting TRIM28 to degrade the inactive cGAS. We revealed the mechanism of host cells regulating antiviral immunity through the Sp1-H1.2-cGAS axis and found plicamycin could be used as a potential anti-infective drug. These data may offer important reference value for innate immune research.

Although many DNA binding natural products exert their effects through non-specific mechanisms, a therapeutic opportunity exists for a subset of these compounds that alter the expression or activity of specific driver oncogenes in specific cell contexts. In this study, we integrate CUT&Tag with Global Run-On Sequencing (CUT, Tag, and GRO) to show that the minor groove binding compound, mithramycin (MMA), inhibits the Ewing sarcoma oncogenic driver, the EWS::FLI1 transcription factor. MMA causes either an increase or decrease in EWS::FLI1 binding to chromatin at downstream target response elements to poison nascent transcription. The reversal of EWS::FLI1 activity is limited by non-specific effects of the drug on RNAPII processivity but can be optimized by continuous administration at low concentration to cause more precise reversal of the oncogenic transcriptome and striking Ewing sarcoma xenograft regressions. The activity in vivo is further improved with a less-toxic second-generation analog, AIT-102.

Persistent androgen receptor (AR) activation is an important contributor to polycystic ovary syndrome (PCOS) and is affected by transcriptional regulation via histone acetylation; however, the underlying mechanisms are partially understood. This study demonstrated that AR activation in ovarian granulosa cells (GCs) of both dehydroepiandrosterone (DHEA) and high-fat diet-induced PCOS mouse models correlated with a significant increase in the histone acetyltransferase p300 and histone acetylation. Conversely, GC-specific p300 knockout or pharmacological inhibition with C646/A-485 effectively reduced AR activation, histone 3 acetylation (H3K18ac/H3K27ac), and ovarian fibrosis in PCOS mice, highlighting p300 as a critical driver. ATAC-seq and RNA-seq identified "open" chromatin regions at the AR promoter in PCOS ovaries, corresponding with increased AR transcription and histone acetylation. p300, along with transcription factor SP1 and the acetyl-reader BRD4, bound to H3K18ac and H3K27ac of the AR promoter in PCOS-modeled ovaries and GCs, which was blocked by C646 and the SP1 inhibitor Plicamycin, respectively. Importantly, continuous AR activation by its ligand DHT largely diminished the anti-fibrotic and ovarian-protective effects of C646. These findings suggest that p300, SP1, and BRD4, form a critical transcriptional complex driving AR activation and PCOS development, and that targeting the p300/AR axis may present a promising therapeutic approach for treating PCOS.

Epigenetic modifications, including histone post-translational modifications, are central drivers of age-associated structural and functional changes in the genome, influencing gene expression and leading to changes in cellular resilience. Epigenetic modifications are thus a target for therapies to prevent or treat age-related decline in health and lifespan. In this study, we measured the effects of inhibiting histone deacetylases (HDACs) and the histone methyltransferase, SETDB1, on lifespan, reproduction, and stress response in the rotifer Brachionus manjavacas, a model organism for aging studies. Rotifers were exposed to three pharmaceutical compounds, the HDAC inhibitors β-hydroxybutyrate and sodium butyrate and the SETDB1 inhibitor mithramycin A. Changes in global histone modification levels, lifespan, reproduction, and heat stress resistance were quantified. Global histone acetylation levels increased with β-hydroxybutyrate and sodium butyrate treatments. Histone 3 lysine 9 trimethylation (H3K9me3) levels were reduced by treatment with mithramycin A. β-hydroxybutyrate significantly extended lifespan without modifying heat stress resistance. In contrast, mithramycin A increased both lifespan and heat stress tolerance. Sodium butyrate specifically improved heat stress resistance without affecting lifespan. Importantly, none of the three treatments had a significant impact on lifetime reproduction. These findings provide insights into the role of histone modifications in aging and suggest potential interventions targeting epigenetic marks to promote longevity and resilience.

Preeclampsia leads to high fetal morbidity and pregnancy-induced mortality. However, the detailed molecular pathology of PE is currently unknown. shp1 has been shown to be critical to the pathogenesis of several diseases, but their role in PE requires further validation. In this study, TPI-1 administration significantly worsened PE mice resulting in impaired spiral artery remodelling. According to Western blot results, TPI-1 administration down-regulated the protein expression of SHP1 and up-regulated the protein expression of p-P38, p-Src. YAP, SP1, and JAG-1 in PE mice. In addition, Shp1 OE promoted Shp1 and p-Shp1 expression and inhibited SMCs cellular NICD, c-Myc, CyclinD1, MMP- through inhibition of trophoblast p-P38, SP1, PI3K, YAP, JAG1 protein expression as determined by in vitro trophoblast cell lines and smooth muscle cells cultured with trophoblast cell serum. 9, MMP-2 expression inhibited the proliferation and migration of SMCs cells. The P38 activator metformin Hcl inhibited the action of Shp1 OE. The SP1 activator plicamycin inhibited the action of metformin hydrochloride. The PI3K activator 740 Y-P inhibited the action of SP1 activator. The YAP inhibitor CA3 (CIL56) inhibited the action of the action of SP1 activators. In summary, SHP1 affects preeclampsia by inhibiting the expression of P38/SP1/PI3K/YAPxd proteins in trophoblast cells, which in turn regulates the protein expression of NICD, c-Myc, CyclinD1, MMP-9, MMP-2 in SMCs cells.