A novel pansharpening method based on cross stage partial network and transformer.

In remote sensing image fusion, the conventional Convolutional Neural Networks (CNNs) extract local features of the image through layered convolution, which is limited by the receptive field and struggles to capture global features. Transformer utilizes self-attention to capture long-distance dependencies in images, which has a global receptive field, but the computational cost for high-resolution images is excessively high. In response to the above issues, this paper draws inspiration from the FusionNet network, harnessing the local detail acquisition capability of CNNs and the global data procuring capacity of Transformer. It presents a novel method for remote sensing image sharpening named Guided Filtering-Cross Stage Partial Network-Transformer, abbreviated as GF-CSTNet. This solution unifies the strengths of Guided Filtering (GF), Cross Stage Partial Network (CSPNet), and Transformer. Firstly, this method utilizes GF to enhance the acquired remote sensing image data. The CSPNet and Transformer structures are then combined to further enhance fusion performance by leveraging their respective advantages. Subsequently, a Rep-Conv2Former method is designed to streamline attention and extract diverse receptive field features through a multi-scale convolution modulator block. Simultaneously, a reparameterization module is constructed to integrate the multiple branches generated during training into a unified branch during inference, thereby optimizing the model's inference speed. Finally, a residual learning module incorporating attention has been devised to augment the modeling and feature extraction capabilities of images. Experimental results obtained from the GaoFen-2 and WorldView-3 datasets demonstrate the effectiveness of the proposed GF-CSTNet approach. It effectively extracts detailed information from images while avoiding the problem of spectral distortion.

HSP90, as a functional target antigen of a mAb 11C9, promotes stemness and tumor progression in hepatocellular carcinoma.

BACKGROUND: Identification of promising targeted antigens that exhibited cancer-specific expression is a crucial step in the development of novel antibody-targeted therapies. We here aimed to investigate the anti-tumor activity of a novel monoclonal antibody (mAb) 11C9 and identify the antibody tractable target in the hepatocellular cancer stem cells (HCSCs). METHODS: The identification of the targeted antigen was conducted using SDS-PAGE, western blot, mass spectrometry, and co-immunoprecipitation. Silence of HSP90 was induced by siRNA interference. Positive cells were sorted by fluorescence-activated cell sorting. Double-immunofluorescent (IF) staining and two-color flow cytometry detected the co-expression. Self-renewal, invasion, and drug resistance were assessed by sphere formation, matrigel-coated Transwell assay, and CCK-8 assay, respectively. Tumorigenicity was evaluated in mouse xenograft models. RNA-seq and bioinformatics analysis were performed to explore the mechanism of mAb 11C9 and potential targets. RESULTS: MAb 11C9 inhibited invasion and self-renewal abilities of HCC cell lines and reversed the cisplatin resistance. HSP90 (~ 95 kDa) was identified as a targeted antigen of mAb 11C9. Tissue microarrays and online databases revealed that HSP90 was overexpressed in HCC and associated with a poor prognosis. FACS and double-IF staining showed the co-expression of HSP90 and CSCs markers (CD90 and ESA). In vitro and in vivo demonstrated the tumorigenic potentials of HSP90. The inhibition of HSP90 by siRNA interference or 17-AAG inhibitor both decreased the number of invasion, sphere cells, and CD90+ or ESA+ cells, as well as reversed the resistance. Bioinformatics analysis and western blot verified that HSP90 activated Wnt/ß-catenin signaling. CONCLUSIONS: The study preliminarily revealed the anti-tumor activity of mAb 11C9. More importantly, we identified HSP90 as a targeted antigen of mAb 11C9, which functions as an oncogene in phenotype shaping, stemness maintenance, and therapeutic resistance by activating Wnt/ß-catenin signaling.

Telaprevir Improves Memory and Cognition in Mice Suffering Ischemic Stroke via Targeting MALT1-Mediated Calcium Overload and Necroptosis.

Mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1) has been confirmed to contribute to brain injury in ischemic stroke via promoting excitotoxicity and necroptosis. Telaprevir, a hepatitis C virus protease inhibitor, is predicted to be a potential MALT1 inhibitor. Here, we showed that telaprevir protected against cerebral ischemic injury via inhibiting MALT1, thereby preventing glutamate receptor ionotropic NMDA 2B (GluN2B) activation, limiting calcium overload, and suppressing necroptosis. In ischemic stroke mice, telaprevir reduced infarct volume, improved the long-term survival rate, and enhanced sensorimotor, memory, and cognitive functions. In hypoxia-treated nerve cells, telaprevir decreased the intracellular calcium concentrations and reduced LDH release. Mechanistically, telaprevir inhibited MALT1 protease activity, thus decreasing the membrane protein level of GluN2B and its phosphorylation through reducing the level of STEP61. Moreover, telaprevir was able to inhibit the levels of necroptosis-associated proteins. According to these results, it can be concluded that telaprevir alleviates neuronal brain injury in stroke mice via restraining GluN2B activation and suppresses the receptor-interacting protein kinase 1 (RIPK1)/receptor-interacting protein kinase 3 (RIPK3)/mixed lineage kinase domain-like pseudokinase (MLKL) pathway through inhibiting MALT1. Thus, telaprevir might have a novel indication for treating patients with ischemic stroke.

[Corrigendum] Hsp90 inhibitor 17­AAG inhibits stem cell­like properties and chemoresistance in osteosarcoma cells via the Hedgehog signaling pathway.

Following the publication of the article, a concerned reader drew to the authors' attention that, in Fig. 1B and C on p. 316, two pairs of the data panels showing the results from invasion and migration assay experiments appeared to be overlapping, such that they would have been derived from the same original sources where they were intended to show the results from different experiments; moreover, on p. 1698, the '17­AAG / MG­63' data panels in Fig. 3B and C were also overlapping, albeit the images were presented at a different scale and in a slightly different orientation. After having examined their original data, the authors have realized that these figures were inadvertently assembled incorrectly. The corrected versions of Figs. 1 and 3, now showing the correct data in Fig. 1C (where the errors made in compiling the figure had occurred) and the correct data for the '17­AAG / MG­63' data panel in Fig. 3C, are shown on the next two pages. These corrections do not grossly affect either the results or the conclusions reported in this work. The authors all agree to the publication of this Corrigendum, and are grateful to the Editor of Oncology Reports for granting them the opportunity to correct the errors that were made during the assembly of these figures. Lastly, the authors apologize to the readership for any inconvenience these errors may have caused. [Oncology Reports 44: 313­324, 2020; DOI: 10.3892/or.2020.7597].

miRNA-381-3p Functions as a Tumor Suppressor to Inhibit Gastric Cancer by Targeting Fibroblast Growth Factor Receptor-2.

Objectives: MicroRNAs possess essential effects on gastric cancer (GC), whereas the underlying mechanisms have not been fully uncovered. The present work focused on investigating the role of miR-381-3p in GC cellular processes and the possible mechanisms. Materials and Methods: miR-381-3p levels within GC tissues and cells were measured through quantitative real-time polymerase chain reaction (qRT-PCR). This study measured cell proliferation, apoptosis, and metastasis through EdU, colony formation, flow cytometry, and Transwell assays separately. TargetScan was adopted to predict the miR-381-3p targets, whereas luciferase reporter assay was adopted for confirmation. Results: miR-381-3p levels were decreased, whereas fibroblast growth factor receptor-2 (FGFR2) expression was increased in GC. miR-381-3p upregulation inhibited proliferation, migration, and invasion and it promoted the apoptosis of GC cells. Further, FGFR2 overexpression partly reversed the miR-381-3p-mediated impacts on GC cellular processes. Conclusions: This study provides an experimental basis, suggesting the potential of using miR-381-3p as the novel marker for GC. Clinical Trial Registration number: 2020-05.

The Weakened Interaction Between HECTD4 and GluN2B in Ischemic Stroke Promotes Calcium Overload and Brain Injury Through a Mechanism Involving the Decrease of GluN2B and MALT1 Ubiquitination.

Glutamate receptor ionotropic NMDA 2B (GluN2B) plays an essential role in calcium overload during excitotoxicity. Reverse-phase nano-liquid chromatography-tandem mass spectrometry has revealed an interaction between GluN2B and HECT domain E3 ubiquitin protein ligase 4 (HECTD4), an E3 ubiquitin ligase highly expressed in the brain. As a potential substrate for HECTD4, mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1) acts as a scaffold with hydrolysis activity. This study explores the relationship between HECTD4, GluN2B, and MALT1, focusing on their role in brain injury in ischemic stroke. Rats were subjected to 2 h-ischemia followed by 24-h reperfusion to establish an ischemic stroke model. We observed the downregulation of HECTD4 and the upregulation of MALT1. Additionally, an increased GluN2B phosphorylation was concomitant with weakened interactions between HECTD4 and GluN2B, followed by decreased striatal-enriched protein phosphatase (STEP61). Knockdown of HECTD4 exacerbated hypoxia- or NMDA-induced injury in nerve cells coincident with a decrease in GluN2B and MALT1 ubiquitination, and an increase in GluN2B phosphorylation as well as an increase in intracellular calcium level, which were counteracted by MALT1 siRNA. Blockage of MALT1 with its inhibitor or siRNA reduced STEP61 degradation, accompanied by a decrease in GluN2B phosphorylation, intracellular calcium concentration, and brain cell injury, which were reversed by overexpression of MALT1. Based on these observations, we conclude that the downregulation of HECTD4 in ischemic stroke rat brain accounts for calcium overload and brain injury due to activating GluN2B directly and indirectly through a mechanism involving the reduced ubiquitination of GluN2B and MALT1, respectively.

Hsa-let-7d-5p Promotes Gastric Cancer Progression by Targeting PRDM5.

Gastric cancer (GC) is a common malignant tumor in the digestive system and a significant health burden worldwide. In this study, we found that hsa-let-7d-5p was upregulated in GC cells, promoted GC cell proliferation, migration, and invasion, and reduced apoptosis. Moreover, we found that the expression of PRDM5 (PR domain protein 5) was downregulated in GC cells and upregulated in GC cells treated with hsa-let-7d-5p inhibitor. Further investigation showed that hsa-let-7d-5p was the target of PRDM5, and the functions of hsa-let-7d-5p on GC progression were rescued by PRDM5 overexpression in GC cells. Collectively, our findings suggested that hsa-let-7d-5p promoted the development of GC by targeting PRDM5, indicating that hsa-let-7d-5p could be a promising therapeutic molecule for the treatment of gastric cancer.

Analysis of microRNA expression in CD133 positive cancer stem­like cells of human osteosarcoma cell line MG-63.

Osteosarcoma (OS) is a primary malignant tumor of bone occurring in young adults. OS stem cells (OSCs) play an important role in the occurrence, growth, metastasis, drug resistance and recurrence of OS. CD133 is an integral membrane glycoprotein, which has been identified as an OSC marker. However, the mechanisms of metastasis, chemoresistance, and progression in CD133(+) OSCs need to be further explored. In this study, we aim to explore differences in miRNA levels between CD133(+) and CD133(-) cells from the MG-63 cell line. We found 20 differentially expressed miRNAs (DEmiRNAs) (16 upregulated and 4 downregulated) in CD133(+) cells compared with CD133(-) cells. Hsa-miR-4485-3p, hsa-miR-4284 and hsa-miR-3656 were the top three upregulated DEmiRNAs, while hsa-miR-487b-3p, hsa-miR-493-5p and hsa-miR-431-5p were the top three downregulated DEmiRNAs. In addition, RT-PCR analysis confirmed that the expression levels of hsa-miR-4284, hsa-miR-4485-3p and hsa-miR-3656 were significantly increased, while the expression levels of hsa-miR-487b-3p, hsa-miR-493-5p, and hsa-miR-431-5p were significantly decreased in CD133(+) cells compared with CD133(-) cells. Moreover, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed that predicted or validated target genes for all 20 DEmiRNAs or the selected 6 DEmiRNAs participated in the "PI3K-Akt signaling pathway," "Wnt signaling pathway," "Rap1 signaling pathway," "Cell cycle" and "MAPK signaling pathway". Among the selected six DEmiRNAs, miR-4284 was especially interesting. MiR-4284 knockdown significantly reduced the sphere forming capacity of CD133(+) OS cells. The number of invasive CD133(+) OS cells was markedly decreased after miR-4284 knockdown. In addition, miR-4284 knockdown increased the p-ß-catenin levels in CD133(+) OS cells. In conclusion, RNA-seq analysis revealed DEmiRNAs between CD133(+) and CD133(-) cells. MiRNAs might play significant roles in the function of OSCs and could serve as targets for OS treatment. MiR-4284 prompted the self-renewal and invasion of OSCs. The function of miR-4284 might be associated with the Wnt signaling pathway.

Alpha-enolase (ENO1), identified as an antigen to monoclonal antibody 12C7, promotes the self-renewal and malignant phenotype of lung cancer stem cells by AMPK/mTOR pathway.

BACKGROUND: Tumor-associated antigens (TAAs) can be targeted in cancer therapy. We previously identified a monoclonal antibody (mAb) 12C7, which presented anti-tumor activity in lung cancer stem cells (LCSCs). Here, we aimed to identify the target antigen for 12C7 and confirm its role in LCSCs. METHODS: Immunofluorescence was used for antigen localization. After targeted antigen purification by electrophoresis and immunoblot, the antigen was identified by LC-MALDI-TOF/TOF mass spectrometry, immunofluorescence, and immunoprecipitation. The overexpression or silence of ENO1 was induced by lentiviral transduction. Self-renewal, growth, and invasion of LCSCs were evaluated by sphere formation, colony formation, and invasion assay, respectively. High-throughput transcriptome sequencing (RNA-seq) and bioinformatics analysis were performed to analyze downstream targets and pathways of targeted antigen. RESULTS: Targeted antigen showed a surface antigen expression pattern, and the 43-55 kDa protein band was identified as α-enolase (ENO1). Self-renewal, growth, and invasion abilities of LCSCs were remarkably inhibited by ENO1 downregulation, while enhanced by ENO1 upregulation. RNA-seq and bioinformatics analysis eventually screened 4 self-renewal-related and 6 invasion-related differentially expressed genes. GSEA analysis and qRT-PCR verified that ENO1 regulated self-renewal, invasion-related genes, and pathways. KEGG pathway analysis and immunoblot demonstrated that ENO1 inactivated AMPK pathway and activated mTOR pathway in LCSCs. CONCLUSIONS: ENO1 is identified as a targeted antigen of mAb 12C7 and plays a pivotal role in facilitating self-renewal, growth, and invasion of LCSCs. These findings provide a potent therapeutic target for the stem cell therapy for lung cancer and have potential to improve the anti-tumor activity of 12C7.

Identifying specific miRNAs and associated mRNAs in CD44 and CD90 cancer stem cell subtypes in gastric cancer cell line SNU-5.

Cancer stem cells (CSCs) are capable of generating multiple types of cells and play a vital role in promoting gastric cancer (GC) progression. Our previous research indicated that gastric CSCs with surface markers of CD44+ were more invasive compared to CD44- CD90+ CSCs (CD90+ CSCs), whereas CD90+ CSCs exhibited higher levels of proliferation than CD44+ CSCs. However, the mechanism and characteristics of marker-positive gastric CSCs are poorly understood. In this study, we profiled expression of miRNAs and mRNAs in CD44+ CSCs, CD90+ CSCs, and CD44- CD90- cell subtype (control) from SNU-5 cells by microarray analysis. Our results suggested some specially expressed miRNA-mRNA pairs in CD44+ and CD90+ CSCs. We performed Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses to analyze the correlation and function of those pairs. We also validated the pairs that may play roles in metastasis by qRT-PCR. In CD44+ CSCs, we observed hsa-miR-15b-5p was up-regulated and its target genes AMOT, USP31, KALRN, EPB41L4B, ATP2B2, and EMC4 were down-regulated, which may relate to invasion and migration. In CD90+ CSCs, we observed hsa-miR-3631-3p is up-regulated, while its target genes QKI, TRIM67 and HMGA2 are down-regulated, which is associated with proliferation. We also found that hsa-miR-1910-5p is up-regulated while its target gene QKI and HMGA2 are down-regulated in CD90+ CSCs. The screened miRNA-mRNA pairs give us new insight into the mechanism of different phenotypes and biomarkers capable of identifying and isolating metastatic and tumorigenic CSCs. Those miRNA-mRNA pairs may also act as treatment for GC.

Hsp90 inhibitor 17­AAG inhibits stem cell­like properties and chemoresistance in osteosarcoma cells via the Hedgehog signaling pathway.

Multiple drug resistance is a major obstacle to the successful treatment of osteosarcoma (OS). Recent studies have demonstrated that a subset of cells, referred to as OS stem cells (OSCs), play a crucial role in the acquisition of multiple drug resistance. Therefore, an improved understanding of OS biology and pathogenesis is required to advance the development of targeted therapies aimed at eradicating this particular subset of cells in order to reverse acquired chemoresistance in OS. The aim of the present study was to assess the anti­OSC effects of 17­AAG and determine the underlying molecular mechanism. Heat shock protein 90 expression was found to be increased in sarcosphere cells and was positively associated with cancer stem cell characteristics. In addition, 17­AAG was able to suppress the stem cell­like phenotype of OS cells. Mechanistically, 17­AAG inhibited OSC­like properties and chemoresistance through glycogen synthase kinase (GSK) 3ß inactivation­mediated repression of the Hedgehog signaling pathway. The findings of the present study provided comprehensive evidence for the inhibition of OSC properties and chemoresistance by 17­AAG through repression of the GSK3ß/Hedgehog signaling pathway, suggesting that 17­AAG may be a promising therapeutic agent for targeting OSCs.

Distinct biological characterization of the CD44 and CD90 phenotypes of cancer stem cells in gastric cancer cell lines.

Recent study implicates that gastric cancer stem cells (CSCs) are capable of generating multiple types of cells to promote tumor growth and heterogeneity important for the development of gastric cancer. However, knowledge is limited regarding the expression and characteristics of marker-positive gastric CSCs. Therefore, gastric CSCs from a series of human gastric cancer cell lines (SNU-5, SNU-16, BGC-823, PAMC-82, MKN-45, and NCI-N87) using four putative CSC surface markers (CD44, CD90, CD133, and epithelial-cell adhesion molecule) were investigated the underlying mechanisms regulating such subpopulations. Only SNU-5 and SNU-16 exhibited independent co-expression of CD44+ and CD90+, which exhibited spheroid-colony formation in vitro and tumor formation in immunodeficient mice. Functional studies revealed that CD44+ cells were more invasive compared with CD90+ cells, whereas CD90+ cells exhibited higher levels of proliferation than CD44+ cells. Furthermore, serial xenotransplantation in mice of CD44+/CD90+ cells derived from SNU-5 and SNU-16 revealed rapid growth of CD90+ cells in subcutaneous lesions and a high metastatic capacity of CD44+ cells in the lung. Mechanistic analyses revealed that CD44+ cells underwent epithelial-to-mesenchymal transition (EMT) following acquisition of mesenchymal features, whereas CD90+ cells enhanced the activation of retinoblastoma phosphorylation at Ser780 and oncogenic cell cycle regulators. The expression of CD44 and CD90 in gastric cancer tissues was associated with distant metastasis and the differentiation state of tumors. These results demonstrated that CD44 and CD90 are specific biomarkers capable of identifying and isolating metastatic and tumorigenic CSCs through their ability to regulate EMT and the cell cycle in gastric cancer cell lines.

Tumor endothelial cells promote metastasis and cancer stem cell-like phenotype through elevated Epiregulin in esophageal cancer.

Tumor endothelial cells have been found to be associated with metastasis and cancer progression. In this study, we reported that human esophageal cancer endothelial cells (HECEC), unlike corresponding human esophageal normal endothelial cells (HENEC) displayed several distinct feature couple with unique gene expression profile. Further studies showed that HECEC can enhance migration, invasion and self-renewal properties of esophageal carcinoma cell in vitro by a direct cell-cell interaction. In vivo assay demonstrated that HECEC could significantly enhance the invasion and lung metastasis of esophageal cancer cells. To elucidate the molecular mechanisms of HECEC in esophageal carcinoma progression, we employed the microarray to analyze the gene expression profiles before and after treating with HECEC, HENEC or conditioned meium from HECEC. Among the highly expressed HECEC-regulated genes, we focused on Epiregulin (EREG). Further studies demonstrated that overexpression of EREG in EC9706 or Kyse30 cells can induce actin reorganization, sphere formation ability and a significantly enrichment of CD44+ cancer stem-like cells. Moreover, up-regulation of EREG in esophageal cancer cells could enhance lung metastasis and decrease the survival time in vivo. Further study indicated that EREG could induce activation of the Src and FAK. In addition, all these effects could also be inhibited by the function-blocking anti-EREG antibody in a dose dependent manner. Immunohistochemical analysis revealed that high level of EREG was significantly correlated with lymph node metastases and poor prognosis. In summary, HECEC play key roles in enhancing the invasion, migration, cancer stem cell phenotype and metastatic potential of esophageal cancer cells through Epiregulin.