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Abstract Background Cholangiocarcinoma (CCA) is a highly malignant, rapidly progressing tumor of the bile duct. Owing to its chemoresistance, it always has an extremely poor prognosis. Therefore, detailed elucidation of the mechanisms of chemoresistance and identification of therapeutic targets are still needed. Methods We analyzed the expression of MBD2 (Methyl-CpG-binding domain 2) in CCA and normal bile duct tissues using the public database and immunohistochemistry (IHC). The roles of MBD2 in CCA cell proliferation, migration, and chemoresistance ability were validated through CCK-8, plate cloning assay, wound healing assays and xenograft mouse model. In addition, we constructed a primary CCA mouse model to further confirm the effect of MBD2. RNA-seq and co-IP-MS were used to identify the mechanisms by how MBD2 leads to chemoresistance. Results MBD2 was upregulated in CCA. It promoted the proliferation, migration and chemoresistance of CCA cells. Mechanistically, MBD2 directly interacted with WDR5, bound to the promoter of ABCB1, promoted the trimethylation of H3K4 in this region through KMT2A, and activated the expression of ABCB1. Knocking down WDR5 or KMT2A blocked the transcriptional activation of ABCB1 by MBD2. The molecular inhibitor MM-102 targeted the interaction of WDR5 with KMT2A. MM-102 inhibited the expression of ABCB1 in CCA cells and decreased the chemoresistance of CCA to cisplatin. Conclusion MBD2 promotes the progression and chemoresistance of CCA through interactions with WDR5. MM-102 can effectively block this process and increase the sensitivity of CCA to cisplatin.

Abstract Background Cholangiocarcinoma (CCA) is a highly malignant tumor characterized by a lack of effective targeted therapeutic strategies. The protein UHRF1 plays a pivotal role in the preservation of DNA methylation and works synergistically with DNMT1. Posttranscriptional modifications (PTMs), such as ubiquitination, play indispensable roles in facilitating this process. Nevertheless, the specific PTMs that regulate UHRF1 in CCA remain unidentified. Methods We confirmed the interaction between STUB1 and UHRF1 through mass spectrometry analysis. Furthermore, we investigated the underlying mechanisms of the STUB1-UHRF1/DNMT1 axis via co-IP experiments, denaturing IP ubiquitination experiments, nuclear‒cytoplasmic separation and immunofluorescence experiments. The downstream PLA2G2A gene, regulated by the STUB1-UHRF1/DNMT1 axis, was identified via RNA-seq. The negative regulatory mechanism of PLA2G2A was explored via bisulfite sequencing PCR (BSP) experiments to assess changes in promoter methylation. The roles of PLA2G2A and STUB1 in the proliferation, invasion, and migration of CCA cells were assessed using the CCK-8 assay, colony formation assay, Transwell assay, wound healing assay and xenograft mouse model. We evaluated the effects of STUB1/UHRF1 on cholangiocarcinoma by utilizing a primary CCA mouse model. Results This study revealed that STUB1 interacts with UHRF1, resulting in an increase in the K63-linked ubiquitination of UHRF1. Consequently, this facilitates the nuclear translocation of UHRF1 and enhances its binding affinity with DNMT1. The STUB1-UHRF1/DNMT1 axis led to increased DNA methylation of the PLA2G2A promoter, subsequently repressing its expression. Increased STUB1 expression in CCA was inversely correlated with tumor progression and overall survival. Conversely, PLA2G2A functions as a tumor suppressor in CCA by inhibiting cell proliferation, invasion and migration. Conclusions These findings suggest that the STUB1-mediated ubiquitination of UHRF1 plays a pivotal role in tumor progression by epigenetically silencing PLA2G2A, underscoring the potential of STUB1 as both a prognostic biomarker and therapeutic target for CCA. Graphical Abstract

Abstract Ten–eleven translocation protein 1 (TET1) functions as an epigenetic regulatory molecule, mediating the majority of DNA demethylation, and plays a role in the development of different types of cancers by regulating the expression of proto‐oncogenes and oncogenes. Here it is found that TET1 is highly expressed in cholangiocarcinoma (CCA) and is associated with a poor prognosis. In addition, TET1 promotes claudin‐3 (CLDN3) transcription by targeting the CLDN3 promoter region between −16 and 512 for demethylation. PPM1G functions as a protein dephosphorylase, catalyzing the dephosphorylation of TET1. This results in the destabilization of the TET1 protein, thereby impairing the targeting of the CLDN3 promoter for demethylation. Two phosphatase inhibitors, staurosporine and AZD0156, inhibit epithelial‐to‐mesenchymal transition (EMT) in cholangiocarcinoma cells by suppressing TET1 expression. In conclusion, it is also demonstrated that PPM1G can be employed as a therapeutic target to impede the progression of CCA by catalyzing the dephosphorylation of TET1, which diminishes the capacity of TET1 to target the CLDN3 promoter to activate transcription and inhibit EMT in CCA.

TianQin is a geocentric space-based gravitational wave detection mission, it will confront a more complex and variable orbital thermal environment compared to heliocentric orbit missions like LISA. As one of the core payloads in TianQin, the telescope requires stringent temperature stability. Furthermore, the telescope operates as an open system directly exposed to the external environment. Besides the solar thermal irradiation, the earth and lunar heat irradiation exist in the TianQin orbit, and may enter the telescope during the observation period. Up to now, the effect of earth–lunar heat flux on the temperature stability of the TianQin telescope has not been addressed. In this article, an innovative algorithm is proposed for accelerating the Gebhart factors calculation, and the detailed evaluation from the direct earth and lunar heat flux to the telescope’s temperature stability has been accomplished. Our findings reveal that the temperature stability of the telescope’s secondary mirror closely approaches the level of total TianQin requirement (about 2 mK/Hz@0.1 mHz and 5μK/Hz@2 mHz) in the absence of a baffle, especially in proximity to frequencies of the 0.1 mHz and 2 mHz. To suppress the heat flux influence, we researched the effect of the geometry and surface thermo-optical property of the baffle on the temperature stability of the telescope. A bunched entrance baffle is optimized by Linear Programming analysis based on the smallest laser aperture and baffle geometric size constraint and then achieved temperature stability of about 0.3 mK/Hz @0.1 mHz for the secondary mirror. In addition, An empirical formula derived from conic curve analysis is utilized to guide the iterative optimization of vanes. Subsequent implementation of vanes within the baffle serves to further suppress the earth and lunar heat flux disturbances, leading to an improved temperature stability of about 0.04 mK/Hz @0.1 mHz and 0.7 μKHz @2 mHz, one order of magnitude below the TianQin total requirement. The methods and results can also provide enlightenment for other similar space missions.

A powder metallurgy superalloy prepared by hot pressing (HP) was forged under static and oscillatory pressures. The microstructure, mechanical properties and fracture behavior of the sample before and after forging were characterized in detail. The results showed that the forging processes could effectively break the prior particle boundaries (PPBs) and reduce the PPBs precipitates, thus significantly improved the mechanical properties of the material. In particular, the hot oscillatory forging (HOF) process increased the tensile elongation and stress rapture life of the hot forged sample by 1.3 and 3.5 times, respectively. The present study suggests that HOF could be a promising technique for preparing high-performance superalloys.

Abstract Background Cholangiocarcinoma (CCA) refers to a collection of malignant tumors that develop from the biliary epithelium. Extensive clinical evidence and epidemiological observations indicate a concerning increase in both the incidence and mortality rates of CCA. Surgical resection is currently the sole available cure for CCA. However, it is unfortunate that only a fraction of patients has access to surgery at the time of diagnosis. Moreover, there is a high incidence of cancer recurrence after resection, and systemic treatments have limited efficacy. Therefore, the identification of novel biomarkers for CCA-targeted molecular therapy remains a crucial task in oncology research. Results Our study demonstrated that low expression of RSPO3 was associated with poorer survival rates in patients with CCA. We found that the RSPO3 promoter DNA was hypermethylated in CCA, which was correlated with the low expression of RSPO3. The expression of RSPO3 was influenced by the balance between the DNA methyltransferase DNMT3a and the DNA demethylase TET1 in CCA. In vitro and in vivo experiments showed that targeting RSPO3 promoter DNA methylation using dCas9DNMT3a promoted tumorigenicity of CCA, while targeted RSPO3 promoter DNA demethylation using dCas9TET1CD inhibited CCA tumorigenicity. Additionally, in our primary CCA model, knockdown of Rspo3 promoted CCA progression, whereas overexpression of Rspo3 inhibited CCA progression. Conclusions Our findings suggest that increased methylation and decreased expression of RSPO3 may indicate a poor prognosis in CCA. Restoring RSPO3 expression by targeting promoter DNA demethylation could offer insights for precise treatment of CCA.

Abstract Background Cholangiocarcinoma (CCA) refers to a collection of malignancies that are associated with a dismal prognosis. Currently, surgical resection is the only way to cure patients with CCA. Available systemic therapy is limited to gemcitabine plus cisplatin; however, this treatment is palliative in nature. Therefore, there is still a need to explore new effective therapeutic targets to intervene against CCA. Methods We analyzed the expression of EZH2 and the prognosis of patients in CCA. The proliferation, migration and invasion of CCA cells after gene knockdown and overexpression were examined and validated by a xenograft model and a primary CCA mouse model with corresponding gene intervention. Targeting DNA methylation, and RNA‐sequencing‐based transcriptomic analysis in EZH2 and SUZ12 knockout CCA cells was performed. Bisulfite sequencing polymerase chain reaction (PCR), chromatin immunoprecipitation‐quantitative PCR (ChIP‐qPCR) and reverse‐ChIP assays were performed for research purposes. Results Increased expression of EZH2 in CCA exhibited a significantly poorer prognosis. DNA hypomethylation of the promoter and increased mRNA levels of secreted frizzled‐related protein 1 (SFRP1) were observed in CCA cells following the inhibition of polycomb repressor complex 2 (PRC2), which was achieved through a knockout of EZH2, SUZ12 and EED, respectively, or treatment with GSK126 and GSK343. Targeting the SFRP1 promoter DNA hypermethylation with dCas9‐DNMT3a decreased the mRNA level of SFRP1. The expression of SFRP1 is regulated by both H3K27me3 and DNA methylation and H3K27me3 plays a crucial role in promoting SFRP1 promotor DNA methylation. GSK343 is a small molecule inhibitor that targets the catalytic activity of EZH2. It effectively inhibits the progression and development of subcutaneous xenografts and primary CCA mouse models. Conclusion Overall, our data strongly suggested that targeting PRC2 promotes the expression of SFRP1, thereby inhibiting the progression of CCA. Key Points/Headlights Cholangiocarcinoma (CCA) exhibits elevated expression of EZH2, SUZ12 and EED, resulting in increased levels of H3K27me3. Targeting polycomb repressor complex 2 (PRC2) leads to the removal of H3K27me3 from the secreted frizzled‐related protein 1 (SFRP1) promoter and DNA hypomethylation, thereby activating the transcription of SFRP1. Inhibiting PRC2, including the use of EZH2 inhibitors, holds promise as a potential strategy for developing anti‐cancer drugs for CCA.

Abstract Objective To evaluate the feasibility and quality of biliary-enteric reconstruction (BER) in laparoscopic radical resection of hilar cholangiocarcinoma (LsRRH) versus open surgery and propose technical recommendations. Methods Data of 38 LsRRH and 54 radical laparotomy resections of hilar cholangiocarcinoma (LtRRH) cases were collected from our institution. BER was evaluated via biliary residuals numbers, number of anastomoses, anastomosis manner, suture method, time consumption, and postoperative complication. Results In the LsRRH group, patients were relatively younger; Bismuth type I had a higher proportion while type IIIa and IV were less and required no revascularization. In LsRRH and LtRRH groups, respectively, the biliary residuals number was 2.54 ± 1.62 and 2.47 ± 1.46 (p > 0.05); the number of anastomoses was 2.04 ± 1.27 and 2.57 ± 1.33 (p > 0.05); the time of BER was 65.67 ± 21.53 and 42.5 ± 19.77 min (p 0.05); 14 ± 10.28 and 17 ± 9.73 days for healing (p 0.05). Neither group had a biliary hemorrhage or bile leakage-related death. Conclusion The selection bias in LsRRH mainly affects tumor resection than BER. Our cohort study indicates that BER in LsRRH is technically feasible and equals anastomotic quality to open surgery. However, its longer and a more significant proportion of total operation time represent that BER has higher technical requirements and is one of the critical rate-limiting steps affecting the minimal invasiveness of LsRRH.

Abstract Homeobox A5 (HOXA5) is a transcription factor in mammalian and can regulate cell differentiation, proliferation, and apoptosis as well as tumorigenesis. However, little is known on whether and how HOXA5 can regulate the malignant behaviors of cholangiocarcinoma. The methylation levels of HOXA5 were evaluated by methylation microarray and bisulfite sequencing PCR. HOXA5 expression in tissue samples was examined by immunohistochemistry and Western blot. The proliferation of tumor cells was assessed by CCK-8, EdU, and nude mouse tumorigenicity assays. The invasion, apoptosis and cell cycling of tumor cells were evaluated by Wound healing assay and flow cytometry. The interaction between HOXA5 and the MXD1 promoter was examined by CUT & Tag assay, luciferase reporter assay and chromatin immunoprecipitation. Hypermethylation in the HOXA5 promoter down-regulated HOXA5 expression in extrahepatic cholangiocarcinoma (ECCA) tissues, which was correlated with worse overall survival. HOXA5 overexpression significantly inhibited the proliferation and tumor growth. HOXA5 overexpression enhanced MXD1 expression by directly binding to the MXD1 promoter in ECCA cells. MXD1 overexpression inhibited the proliferation and tumor growth while MXD1 silencing abrogated the HOXA5-mediated proliferation inhibition. HOXA5 overexpression increased p53 protein expression in an MXD1-dependent manner. HOXA5 and MXD1 acted as tumor suppressors to inhibit the mitosis of ECCA cells by enhancing the p53 signaling. Our findings may uncover molecular mechanisms by which the HOXA5/MXD1 axis regulates the progression of ECCA, suggesting that the HOXA5/MXD1 may be therapeutic targets for ECCA.

Abstract Background Accumulating evidence has demonstrated the close relation of SOX1 with tumorigenesis and tumor progression. Upregulation of SOX1 was recently shown to suppress growth of human cancers. However, the expression and role of SOX1 in cholangiocarcinoma (CCA) is not well characterized. Methods Expression levels of SOX1 in CCA tissues and normal bile duct tissues were examined using public GEO database. Western blot and immunohistochemistry were used to confirm the expression levels. Cell proliferation assay (CCK-8) and colony formation assay were performed to assess proliferation of CCA cells. A mouse model of subcutaneous transplantable tumors was used to evaluated proliferation of CCA in vivo. The putative regulating factor of SOX1 were determined using Targetscan and dual-luciferase reporter assay. Results SOX1 was downregulated in CCA tissues. Overexpression of SOX1 significantly inhibited cell proliferation in vitro and suppressed tumor growth in vivo. miR-155-5p directly targeted the 3′-untranslated region (3′UTR) of SOX1 and inhibited expression of SOX1, resulting in the activation of RAF, MEK and ERK phosphorylation, and thus CCA proliferation. However, restoration of SOX1 expression in miR-155-5p overexpressing cell lines decreased the phosphorylation level of RAF, MEK and ERK, as well as the proliferation of CCA cells. Conclusion MiR-155-5p decreased the expression of SOX1 by binding to its 3′UTR, which activated the RAF/MEK/ERK signaling pathway and promoted CCA progression.

Abstract Background The ten-eleven translocation 1 (TET1) protein is a 5-methylcytosine hydroxylase that belongs to the TET protein family of human α-ketoglutarate oxygenases. TET1 recognizes and binds to regions of high genomic 5′-CpG-3′ dinucleotide density, such as CpG islands, initiates the DNA demethylation program, and maintains DNA methylation and demethylation balance to maintain genomic methylation homeostasis and achieve epigenetic regulation. This article reviews the recent research progress of TET1 in the mechanism of demethylation, stem cells and immunity, various malignant tumours and other clinical diseases. Conclusion TET1 acts as a key factor mediating demethylation, the mechanism of which still remains to be investigated in detail. TET1 is also critical in maintaining the differentiation pluripotency of embryonic stem cells and plays anti- or oncogenic roles in combination with different signalling pathways in different tumours. In certain tumours, its role is still controversial. In addition, the noncatalytic activity of TET1 has gradually attracted attention and has become a new direction of research in recent years.

Suppressor of mother against decapentaplegic (SMAD) family proteins are central to one of the most versatile cytokine signalling pathways in metazoan biology, the transforming growth factor-β (TGF-β) pathway. The TGF-β pathway is widely known for its dual role in cancer progression as both an inhibitor of tumour cell growth and an inducer of tumour metastasis. This is mainly mediated through SMAD proteins and their cofactors or regulators. SMAD proteins act as transcription factors, regulating the transcription of a wide range of genes, and their rich post-translational modifications are influenced by a variety of regulators and cofactors. The complex role, mechanisms, and important functions of SMAD proteins in tumours are the hot topics in current oncology research. In this paper, we summarize the recent progress on the effects and mechanisms of SMAD proteins on tumour development, diagnosis, treatment and prognosis, and provide clues for subsequent research on SMAD proteins in tumours.

Because of the high cost of experimental data acquisition, the limited size of the sample set available when conducting tissue structure ultrasound evaluation can cause the evaluation model to have low accuracy. To address such a small-sample problem, the sample set size can be expanded by using virtual samples. In this study, an ultrasound evaluation method for the primary α phase grain size based on the generation of virtual samples by a generative adversarial network (GAN) was developed. TC25 titanium alloy forgings were treated as the research object. Virtual samples were generated by the GAN with a fully connected network of different sizes used as the generator and discriminator. A virtual sample screening mechanism was constructed to obtain the virtual sample set, taking the optimization rate as the validity criterion. Moreover, an ultrasound evaluation optimization problem was constructed with accuracy as the target. It was solved by using support vector machine regression to obtain the final ultrasound evaluation model. A benchmark function was adopted to verify the effectiveness of the method, and a series of experiments and comparison experiments were performed on the ultrasound evaluation model using test samples. The results show that the learning accuracy of the original small samples can be increased by effective virtual samples. The ultrasound evaluation model built based on the proposed method has a higher accuracy and better stability than other models.

Hilar cholangiocarcinoma (HCCA) is widely considered to have a poor prognosis. In particular, combined caudate lobe resection (CLR) as a strategy for radical resection in HCCA is important for improving the R0 resection rate. However, the criteria for R0 resection, necessity of CLR, optimal extent of hepatic resection, and surgical approach are still controversial. This review aimed to summarize the findings and discuss the controversies surrounding CLR. Numerous clinical studies have shown that combined CLR treatment for HCCA improves the R0 resection rate and postoperative survival time. Whether surgery for Bismuth type I or II is combined with CLR depends on the pathological type. Considering the anatomical factors, total rather than partial CLR is recommended to achieve a higher R0 resection rate. In the resection of HCCA, a proximal ductal margin greater than or equal to 10 mm should be achieved to obtain a survival benefit. Although there is no obvious boundary between the right side (especially the paracaval portion) and the right posterior lobe of the liver, Peng's resection line can serve as a reference marker for right-sided resection. Laparoscopic resection of the caudate lobe may be safer, more convenient, accurate, and minimally invasive than open surgery, but it needs to be completed by experienced laparoscopic doctors. [ABSTRACT FROM AUTHOR]

In this work, the effects of microstructure on the ultrasonic response of nickel-based superalloy GH706 (Inconel 706) were examined. The nickel-based superalloy was heat-treated under solution treatment, stabilising treatment and ageing treatment conditions. Metallographic tests were carried out and scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images were taken to examine the microstructure of GH706. The ultrasonic and non-linear ultrasonic responses were detected and used for calculations. The results showed that changes in grain size directly affected the ultrasonic attenuation coefficient. In the cases where grain refinement was the main factor influencing the hardness of the specimens, changes in both longitudinal wave velocity and hardness were correlated to changes in grain size. However, it was found that if coherency strain is the main factor influencing hardness, the non-linear coefficient is sensitive to changes in both grain boundary structure and hardness, with greater incoherency at the grain boundaries correlating to a greater value for the non-linear coefficient. Finally, it was shown that changes in grain shape had only a minimal influence on the ultrasonic response. [ABSTRACT FROM AUTHOR]