DNA Methylation-Regulated HOXC8's Role in HER2-Positive Breast Cancer Function and its Contribution to Herceptin Resistance.

BACKGROUND: The epidermal growth factor receptor 2 (HER2) is overexpressed in 30% of breast cancers, and this overexpression is strongly correlated with a poor prognosis. Herceptin is a common treatment for HER2-positive breast cancer; however, cancer cells tend to adapt gradually to the drug, rendering it ineffective. The study revealed an association between the methylation status of the Homeobox C8 (HOXC8) gene and tumor development. Therefore, it is of paramount importance to delve into the interaction between HOXC8 and HER2-positive breast cancer, along with its molecular mechanisms. This exploration holds significant implications for a deeper understanding of the pathophysiological processes underlying HER2-positive breast cancer. METHOD: Tumor tissue and pathological data from patients with HER2-positive breast cancer were systematically collected. Additionally, the human HER2-positive breast cancer cell line, SKBR3, was cultured in vitro to assess both the expression level of HOXC8 and the degree of DNA methylation. The study aimed to explore the relationship between the relative expression of HOXC8 and the clinical characteristics of breast cancer patients. The expression level of HOXC8 and the promoter methylation of HOXC8 were verified by methylation treatment of SKBR3 breast cancer cells. The regulation of HOXC8 was meticulously carried out, leading to the division of the cells into distinct groups. The study further analyzed the expression levels and biological capabilities within each group. Finally, the in vitro and in vivo sensitivity of the cells to Herceptin, a common treatment for HER2-positive breast cancer, was measured to assess the efficacy of the drug. RESULT: In HER2-positive breast cancer cases characterized by poor methylation, there was an up-regulation of HOXC8. Its expression was found to be correlated with key clinical factors such as tumor size, lymph node status, clinical tumor, node, metastasis (cTNM) staging, and Herceptin resistance (p < 0.05). Upon methylation of breast cancer cells, there was a significant decrease in HOXC8 expression (p < 0.05). The study revealed that overexpression of HOXC8 resulted in increased proliferation, cloning, and metastasis of HER2-positive breast cancer cells, along with a reduced apoptosis rate (p < 0.05). Conversely, interference with HOXC8 expression reversed this scenario (p < 0.05). A Herceptin-resistant substrain, POOL2, was established using SKBR3 cells. Animal studies demonstrated that overexpressing HOXC8 accelerated tumor development and enhanced POOL2 cells' resistance to Herceptin (p < 0.05). However, following interference with HOXC8, POOL2 cells exhibited increased responsiveness to Herceptin, leading to a gradual reduction in tumor size (p < 0.05). CONCLUSIONS: In HER2-positive breast cancer, the expression of HOXC8 is elevated in a manner dependent on DNA methylation, and this elevated expression is closely linked to the pathology of the patient. Interfering with HOXC8 expression demonstrates the potential to partially inhibit the development and spread of breast cancer, as well as to alleviate resistance to Herceptin.

Characterization of Transthyretin Mutation G47V Associated with Hereditary Cardiac Amyloidosis.

INTRODUCTION: Amyloidosis caused by TTR mutations (ATTRv) is a rare inherited and autosomal dominant disease. More than 150 mutants of TTR have been reported, whereas some of them remain to be investigated. METHODS: A 52-year-old male presented with heart failure and clinically diagnosed ATTR cardiac amyloidosis (ATTR-CA) was recruited. Whole exome sequencing (WES) was performed. Biochemical and biophysical experiments characterized protein stability using urea-mediated tryptophan fluorescence. Drug response was analyzed by fibril formation assay. Finally, tetramer TTR concentration in patient' serum sample was measured by ultra-performance liquid chromatography (UPLC). RESULTS: For the proband, whole exome sequencing revealed a mutation (c.200G>T; p.Gly67Val and referred to as G47V) in TTR gene. Biochemical and biophysical kinetics study showed that the thermodynamic stability of G47V-TTR (Cm = 2.4 M) was significantly lower than that of WT-TTR (Cm = 3.4 M) and comparable to that of L55P-TTR (Cm = 2.3 M), an early age-of-onset mutation. G47V:WT-TTR heterozygous tetramers kinetic stability (t1/2 = 1.4 h) was further compromised compared to that of the homozygous G47V-TTR (t1/2 = 3.1 h). Among three small molecule stabilizers, AG10 exhibited the best inhibition of the fibrillation of G47V-TTR homozygous protein. Using a UPLC assay, nearly 40% of TTR in this patient was calculated to be non-tetrameric. CONCLUSION: In this work, we reported a patient presented early onset of clinically typical ATTR-CM due to G47V-TTR mutation. Our work not only for the first time characterized the biochemical properties of G47V-TTR mutation, but also provided hints for the pathogenicity of this mutation.

Molecular mechanism of NAD+ and NMN binding to the Nudix homology domains of DBC1.

Deleted in breast cancer 1 (DBC1) is a human nuclear protein that modulates the activities of various proteins involved in cell survival and cancer progression. Oxidized form of nicotinamide adenine dinucleotide (NAD+) is suggested to bind to the Nudix homology domains (NHDs) of DBC1, thereby regulating DBC1-Poly (ADP-ribose) polymerase 1 (PARP1) interactions, resulting in the restoration of DNA repair. Using Nuclear Magnetic Resonance (NMR) and Isothermal Titration Calorimetry (ITC), we confirmed NAD+ and its precursor nicotinamide mononucleotide (NMN) both bind the NHD domain of DBC1 (DBC1354-396). NAD+ likely interacts with DBC1354-396 through hydrogen bonding, with a binding affinity (8.99 µM) nearly twice that of NMN (17.0 µM), and the key binding sites are primarily residues E363 and D372, in the agreement with Molecular Docking experiments. Molecular Dynamics (MD) simulation further demonstrated E363 and D372's anchoring role in the binding process. Additional mutagenesis experiments of E363 and D372 confirmed their critical involvement of ligand-protein interactions. These findings lead to a better understanding of how NAD+ and NMN regulate DBC1, thereby offering insights for the development of targeted therapies and drug research focused on DBC1-associated tumors.

Characterization of wheat Wrab18 gene promoter and expression analysis under abiotic stress.

BACKGROUND: Promoters play key roles in plant gene expression in complex and varied natural environments. The type and amount of cis-acting elements in the promoter sequence tend to indicate the response of genes to induction factors. WRAB18 is a group III member of the late embryogenesis abundant (LEA) protein family that performs multiple functions in plant stress physiology. To elucidate the particularly biological effects of WRAB18 on stress, exploration of its promoter sequence is necessary. METHODS AND RESULTS: In this study, the full-length and promoter sequences of Wrab18 were isolated from the Zhengyin 1 cultivar of Triticum aestivum. The gene sequences and cis-acting elements in the promoter were analyzed using the Plant Promoter Database and bioinformatics methods. The results showed that Wrab18 possessed one intron with 100 bp, the promoter sequence contained various stress-related cis-acting elements, and the functionality of the promoter was checked using green fluorescent protein (GFP) marker protein expression by transient assay in Nicotiana benthamiana. Furthermore, based on promoter prediction analysis, quantitative real-time fluorescent PCR results confirmed the response of gene expression levels to stress factors. CONCLUSIONS: In summary, the promoter sequence of Wrab18 plays a role in plant stress responses, contains multiple cis-acting elements, and provides insights into the role of WRAB18 in plant resilience to stress. This study has guiding significance for further studies of gene function and mechanism of action, and lays a theoretical foundation for improving wheat quality.

Minimally invasive bioprinting for in situ liver regeneration.

In situ bioprinting is promising for developing scaffolds directly on defect models in operating rooms, which provides a new strategy for in situ tissue regeneration. However, due to the limitation of existing in situ biofabrication technologies including printing depth and suitable bioinks, bioprinting scaffolds in deep dermal or extremity injuries remains a grand challenge. Here, we present an in vivo scaffold fabrication approach by minimally invasive bioprinting electroactive hydrogel scaffolds to promote in situ tissue regeneration. The minimally invasive bioprinting system consists of a ferromagnetic soft catheter robot for extrusion, a digital laparoscope for in situ monitoring, and a Veress needle for establishing a pneumoperitoneum. After 3D reconstruction of the defects with computed tomography, electroactive hydrogel scaffolds are printed within partial liver resection of live rats, and in situ tissue regeneration is achieved by promoting the proliferation, migration, and differentiation of cells and maintaining liver function in vivo.

Research on Preparation and Properties of Carbon Fiber Reinforced Zinc-Based Aluminum Rich Alloy Composite.

Aiming at the problems of poor bonding between the carbon fiber and the metal matrix and the friction and wear performance of the composite material during the preparation of carbon fiber reinforced zinc-based aluminum rich alloy composites, the carbon fiber surface metallization process was studied. Taking ZA27 as the research object, a new type of zinc-based aluminum rich alloy composite material was prepared by using surface metallized chopped carbon fibers with different contents as reinforcement materials. The microscopic morphology, element distribution and phase composition of the surface metallized carbon fiber and composite materials were characterized, and the hardness and friction and wear properties of the composite materials were tested. The results show that: the surface metallization of carbon fiber effectively reduces the diffusion of carbon elements into the matrix material during the sintering process, and improves the interface bonding between the carbon fiber and the matrix material; Compared with ZA27 alloy, the hardness of 6vt% carbon fiber is increased by 29.6%, and the average friction coefficient and wear rate are reduced by about 18.4% and 96%, respectively, indicating that the carbon fiber reinforced zinc-based aluminum rich alloy composite material optimizes the friction and wear performance of traditional materials.

Induced phase separation of mutant NF2 imprisons the cGAS-STING machinery to abrogate antitumor immunity.

Missense mutations of the tumor suppressor Neurofibromin 2 (NF2/Merlin/schwannomin) result in sporadic to frequent occurrences of tumorigenesis in multiple organs. However, the underlying pathogenicity of NF2-related tumorigenesis remains mostly unknown. Here we found that NF2 facilitated innate immunity by regulating YAP/TAZ-mediated TBK1 inhibition. Unexpectedly, patient-derived individual mutations in the FERM domain of NF2 (NF2m) converted NF2 into a potent suppressor of cGAS-STING signaling. Mechanistically, NF2m gained extreme associations with IRF3 and TBK1 and, upon innate nucleic acid sensing, was directly induced by the activated IRF3 to form cellular condensates, which contained the PP2A complex, to eliminate TBK1 activation. Accordingly, NF2m robustly suppressed STING-initiated antitumor immunity in cancer cell-autonomous and -nonautonomous murine models, and NF2m-IRF3 condensates were evident in human vestibular schwannomas. Our study reports phase separation-mediated quiescence of cGAS-STING signaling by a mutant tumor suppressor and reveals gain-of-function pathogenesis for NF2-related tumors by regulating antitumor immunity.

Effect of K-/S- segments on subcellular localization and dimerization of wheat dehydrin WZY1-2.

Dehydrins (DHNs) belong to group Ⅱ late embryogenesis abundant (LEA) proteins which perform multiple functions in plants during stress conditions. Both K- and S-segments are conserved domains in the dehydrin protein family; however, there are only a few in vivo functional studies for these two conserved segments. In this study, the DHN gene wzy1-2 was isolated from Triticum aestivum and its K-/S-segment-truncated derivatives were generated. In order to explore the biological function of these two conserved fragments, subcellular localization and dimerization detection assays were performed for the K-/S-segment-truncated derivatives. Results of GFP fusion and bimolecular fluorescence complementation (BiFC) assays indicated that WZY1-2 localized to nucleus as a homologous dimer. The S-segment partially regulated the nuclear localization of WZY1-2 but did not affect its dimerization, while the K-segment influenced neither the dimer formation nor the subcellular localization.

MiR-483 Targeted SOX3 to Suppress Glioma Cell Migration, Invasion and Promote Cell Apoptosis.

OBJECTIVE: Glioma is the most common malignant brain tumor that has high aggressiveness. The aim of this study was to investigate the potential therapeutic targets for gliomas. MATERIALS AND METHODS: Real-time quantitative polymerase chain reaction (RT-qPCR) was employed to calculate the expression of miRNA and genes. The connection between the expression of miR-483 and patients' overall survival rate was evaluated using Kaplan-Meier analysis. In addition, the underlying mechanism was detected using luciferase assay. RESULTS: The expression level of miR-483 was significantly decreased in glioma tissue samples and cell lines, compared to the adjacent tissues and normal cell lines. Downregulation of miR-483 or upregulation of SOX3 was associated with overall survival of glioma patients. Additionally, overexpression of miR-483 promotes cell invasion and migration and inhibits apoptosis. In addition, miR-483 directly targeted to SOX3, and the expression of miR-483 has a negative correlation with SOX3 in glioma tissues. SOX3 reversed partial functions of miR-483 on cell migration, invasion, and promoted cell apoptosis in glioma. CONCLUSION: MiR-483 inhibited glioma cell migration, invasion, and promoted glioma cell apoptosis by targeting SOX3. MiR-483 maybe acted as a potential target for the treatment of glioma.

Lck/Hck/Fgr-Mediated Tyrosine Phosphorylation Negatively Regulates TBK1 to Restrain Innate Antiviral Responses.

Cytosolic nucleic acid sensing elicits interferon production for primary antiviral defense through cascades controlled by protein ubiquitination and Ser/Thr phosphorylation. Here we show that TBK1, a core kinase of antiviral pathways, is inhibited by tyrosine phosphorylation. The Src family kinases (SFKs) Lck, Hck, and Fgr directly phosphorylate TBK1 at Tyr354/394, to prevent TBK1 dimerization and activation. Accordingly, antiviral sensing and resistance were substantially enhanced in Lck/Hck/Fgr triple knockout cells and ectopic expression of Lck/Hck/Fgr dampened the antiviral defense in cells and zebrafish. Small-molecule inhibitors of SFKs, which are conventional anti-tumor therapeutics, enhanced antiviral responses and protected zebrafish and mice from viral attack. Viral infection induced the expression of Lck/Hck/Fgr through TBK1-mediated mobilization of IRF3, thus constituting a negative feedback loop. These findings unveil the negative regulation of TBK1 via tyrosine phosphorylation and the functional integration of SFKs into innate antiviral immunity.

Dynamic concision for three-dimensional reconstruction of human organ built with virtual reality modelling language (VRML).

This research studies the process of 3D reconstruction and dynamic concision based on 2D medical digital images using virtual reality modelling language (VRML) and JavaScript language, with a focus on how to realize the dynamic concision of 3D medical model with script node and sensor node in VRML. The 3D reconstruction and concision of body internal organs can be built with such high quality that they are better than those obtained from the traditional methods. With the function of dynamic concision, the VRML browser can offer better windows for man-computer interaction in real-time environment than ever before. 3D reconstruction and dynamic concision with VRML can be used to meet the requirement for the medical observation of 3D reconstruction and have a promising prospect in the fields of medical imaging.