Pre-Defined Stem-Loop Structure Library for the Discovery of L-RNA Aptamers that Target RNA G-Quadruplexes.

L-RNA aptamers have been developed to target G-quadruplexes (G4s) and regulate G4-mediated gene expression. However, the aptamer selection process is laborious and challenging, and aptamer identification is subjected to high failure rate. By analyzing the previously reported G4-binding L-RNA aptamers, we found that the stem-loop (SL) structure is favored by G4 binding. Herein, we present a robust and effective G4-SLSELEX-Seq platform specifically for G4 targets by introducing a pre-defined stem-loop structure library during SELEX process. Using G4-SLSELEX-Seq, we rapidly identified an L-RNA aptamer, L-Apt1-12 for EBNA1 RNA G4 (rG4) in just three selection rounds. L-Apt1-12 maintained the stem-loop structure initially introduced, and possessed a unique G-triplex motif that is important for the strong binding affinity and specificity to EBNA1 rG4. Notably, L-Apt1-12 effectively downregulated endogenous EBNA1 protein expression in human cancer cells and showed selective toxicity towards EBV-positive cancer cells, highlighting its potential for targeted therapy against EBV-associated cancers. Furthermore, we demonstrate the robustness and generality of G4-SLSELEX-Seq by selecting L-RNA aptamers for another two G4 targets-APP rG4 and HCV-1a rG4, also obtaining high-affinity aptamers in three selection rounds. These findings demonstrated G4-SLSELEX-Seq can be a robust and efficient platform for the selection of L-RNA aptamers targeting rG4.

FOXP4 Is a Direct YAP1 Target That Promotes Gastric Cancer Stemness and Drives Metastasis.

The Hippo-YAP1 pathway is an evolutionally conserved signaling cascade that controls organ size and tissue regeneration. Dysregulation of Hippo-YAP1 signaling promotes initiation and progression of several types of cancer, including gastric cancer. As the Hippo-YAP1 pathway regulates expression of thousands of genes, it is important to establish which target genes contribute to the oncogenic program driven by YAP1 to identify strategies to circumvent it. In this study, we identified a vital role of forkhead box protein 4 (FOXP4) in YAP1-driven gastric carcinogenesis by maintaining stemness and promoting peritoneal metastasis. Loss of FOXP4 impaired gastric cancer spheroid formation and reduced stemness marker expression, whereas FOXP4 upregulation potentiated cancer cell stemness. RNA sequencing analysis revealed SOX12 as a downstream target of FOXP4, and functional studies established that SOX12 supports stemness in YAP1-induced carcinogenesis. A small-molecule screen identified 42-(2-tetrazolyl) rapamycin as a FOXP4 inhibitor, and targeting FOXP4 suppressed gastric cancer tumor growth and enhanced the efficacy of 5-fluorouracil chemotherapy in vivo. Collectively, these findings revealed that FOXP4 upregulation by YAP1 in gastric cancer regulates stemness and tumorigenesis by upregulating SOX12. Targeting the YAP1-FOXP4-SOX12 axis represents a potential therapeutic strategy for gastric cancer. Significance: Hippo-YAP1 signaling maintains stemness in gastric cancer by upregulating FOXP4, identifying FOXP4 as a stemness biomarker and therapeutic target that could help improve patient outcomes.

Synthetic BZLF1-targeted transcriptional activator for efficient lytic induction therapy against EBV-associated epithelial cancers.

The unique virus-cell interaction in Epstein-Barr virus (EBV)-associated malignancies implies targeting the viral latent-lytic switch is a promising therapeutic strategy. However, the lack of specific and efficient therapeutic agents to induce lytic cycle in these cancers is a major challenge facing clinical implementation. We develop a synthetic transcriptional activator that specifically activates endogenous BZLF1 and efficiently induces lytic reactivation in EBV-positive cancer cells. A lipid nanoparticle encapsulating nucleoside-modified mRNA which encodes a BZLF1-specific transcriptional activator (mTZ3-LNP) is synthesized for EBV-targeted therapy. Compared with conventional chemical inducers, mTZ3-LNP more efficiently activates EBV lytic gene expression in EBV-associated epithelial cancers. Here we show the potency and safety of treatment with mTZ3-LNP to suppress tumor growth in EBV-positive cancer models. The combination of mTZ3-LNP and ganciclovir yields highly selective cytotoxic effects of mRNA-based lytic induction therapy against EBV-positive tumor cells, indicating the potential of mRNA nanomedicine in the treatment of EBV-associated epithelial cancers.

Establishment and Characterization of an Epstein-Barr Virus-positive Cell Line from a Non-keratinizing Differentiated Primary Nasopharyngeal Carcinoma.

Nasopharyngeal carcinoma (NPC), a cancer that is etiologically associated with the Epstein-Barr virus (EBV), is endemic in Southern China and Southeast Asia. The scarcity of representative NPC cell lines owing to the frequent loss of EBV episomes following prolonged propagation and compromised authenticity of previous models underscores the critical need for new EBV-positive NPC models. Herein, we describe the establishment of a new EBV-positive NPC cell line, designated NPC268 from a primary non-keratinizing, differentiated NPC tissue. NPC268 can undergo productive lytic reactivation of EBV and is highly tumorigenic in immunodeficient mice. Whole-genome sequencing revealed close similarities with the tissue of origin, including large chromosomal rearrangements, while whole-genome bisulfite sequencing and RNA sequencing demonstrated a hypomethylated genome and enrichment in immune-related pathways, respectively. Drug screening of NPC268 together with six other NPC cell lines using 339 compounds, representing the largest high-throughput drug testing in NPC, revealed biomarkers associated with specific drug classes. NPC268 represents the first and only available EBV-positive non-keratinizing differentiated NPC model, and extensive genomic, methylomic, transcriptomic, and drug response data should facilitate research in EBV and NPC, where current models are limited. SIGNIFICANCE: NPC268 is the first and only EBV-positive cell line derived from a primary non-keratinizing, differentiated nasopharyngeal carcinoma, an understudied but important subtype in Southeast Asian countries. This model adds to the limited number of authentic EBV-positive lines globally that will facilitate mechanistic studies and drug development for NPC.

Cellular zinc metabolism and zinc signaling: from biological functions to diseases and therapeutic targets.

Zinc metabolism at the cellular level is critical for many biological processes in the body. A key observation is the disruption of cellular homeostasis, often coinciding with disease progression. As an essential factor in maintaining cellular equilibrium, cellular zinc has been increasingly spotlighted in the context of disease development. Extensive research suggests zinc's involvement in promoting malignancy and invasion in cancer cells, despite its low tissue concentration. This has led to a growing body of literature investigating zinc's cellular metabolism, particularly the functions of zinc transporters and storage mechanisms during cancer progression. Zinc transportation is under the control of two major transporter families: SLC30 (ZnT) for the excretion of zinc and SLC39 (ZIP) for the zinc intake. Additionally, the storage of this essential element is predominantly mediated by metallothioneins (MTs). This review consolidates knowledge on the critical functions of cellular zinc signaling and underscores potential molecular pathways linking zinc metabolism to disease progression, with a special focus on cancer. We also compile a summary of clinical trials involving zinc ions. Given the main localization of zinc transporters at the cell membrane, the potential for targeted therapies, including small molecules and monoclonal antibodies, offers promising avenues for future exploration.

The molecular classification of cancer-associated fibroblasts on a pan-cancer single-cell transcriptional atlas.

BACKGROUND: Cancer-associated fibroblasts (CAFs), integral to the tumour microenvironment, are pivotal in cancer progression, exhibiting either pro-tumourigenic or anti-tumourigenic functions. Their inherent phenotypic and functional diversity allows for the subdivision of CAFs into various subpopulations. While several classification systems have been suggested for different cancer types, a unified molecular classification of CAFs on a single-cell pan-cancer scale has yet to be established. METHODS: We employed a comprehensive single-cell transcriptomic atlas encompassing 12 solid tumour types. Our objective was to establish a novel molecular classification and to elucidate the evolutionary trajectories of CAFs. We investigated the functional profiles of each CAF subtype using Single-Cell Regulatory Network Inference and Clustering and single-cell gene set enrichment analysis. The clinical relevance of these subtypes was assessed through survival curve analysis. Concurrently, we employed multiplex immunofluorescence staining on tumour tissues to determine the dynamic changes of CAF subtypes across different tumour stages. Additionally, we identified the small molecule procyanidin C1 (PCC1) as a target for matrix-producing CAF (matCAF) using molecular docking techniques and further validated these findings through in vitro and in vivo experiments. RESULTS: In our investigation of solid tumours, we identified four molecular clusters of CAFs: progenitor CAF (proCAF), inflammatory CAF (iCAF), myofibroblastic CAF (myCAF) and matCAF, each characterised by distinct molecular traits. This classification was consistently applicable across all nine studied solid tumour types. These CAF subtypes displayed unique evolutionary pathways, functional roles and clinical relevance in various solid tumours. Notably, the matCAF subtype was associated with poorer prognoses in several cancer types. The targeting of matCAF using the identified small molecule, PCC1, demonstrated promising antitumour activity. CONCLUSIONS: Collectively, the various subtypes of CAFs, particularly matCAF, are crucial in the initiation and progression of cancer. Focusing therapeutic strategies on targeting matCAF in solid tumours holds significant potential for cancer treatment.

H. pylori-induced NF-κB-PIEZO1-YAP1-CTGF axis drives gastric cancer progression and cancer-associated fibroblast-mediated tumour microenvironment remodelling.

BACKGROUND: Gastric cancer (GC) is one of the most common tumours in East Asia countries and is associated with Helicobacter pylori infection. H. pylori utilizes virulence factors, CagA and VacA, to up-regulate pro-inflammatory cytokines and activate NF-κB signaling. Meanwhile, the PIEZO1 upregulation and cancer-associated fibroblast (CAF) enrichment were found in GC progression. However, the mechanisms of PIEZO1 upregulation and its involvement in GC progression have not been fully elucidated. METHODS: The CAF enrichment and clinical significance were investigated in animal models and primary samples. The expression of NF-κB and PIEZO1 in GC was confirmed by immunohistochemistry staining, and expression correlation was analysed in multiple GC datasets. GSEA and Western blot analysis revealed the YAP1-CTGF axis regulation by PIEZO1. The stimulatory effects of CTGF on CAFs were validated by the co-culture system and animal studies. Patient-derived organoid and peritoneal dissemination models were employed to confirm the role of the PIEZO1-YAP1-CTGF cascade in GC. RESULTS: Both CAF signature and PIEZO1 were positively correlated with H. pylori infection. PIEZO1, a mechanosensor, was confirmed as a direct downstream of NF-κB to promote the transformation from intestinal metaplasia to GC. Mechanistic studies revealed that PIEZO1 transduced the oncogenic signal from NF-κB into YAP1 signaling, a well-documented oncogenic pathway in GC progression. PIEZO1 expression was positively correlated with the YAP1 signature (CTGF, CYR61, and c-Myc, etc.) in primary samples. The secreted CTGF by cancer cells stimulated the CAF infiltration to form a stiffened collagen-enrichment microenvironment, thus activating PIEZO1 to form a positive feedback loop. Both PIEZO1 depletion by shRNA and CTGF inhibition by Procyanidin C1 enhanced the efficacy of 5-FU in suppressing the GC cell peritoneal metastasis. CONCLUSION: This study elucidates a novel driving PIEZO1-YAP1-CTGF force, which opens a novel therapeutic avenue to block the transformation from precancerous lesions to GC. H. pylori-NF-κB activates the PIEZO1-YAP1-CTGF axis to remodel the GC microenvironment by promoting CAF infiltration. Targeting PIEZO1-YAP1-CTGF plus chemotherapy might serve as a potential therapeutic option to block GC progression and peritoneal metastasis.

Exploring the Microbiome in Gastric Cancer: Assessing Potential Implications and Contextualizing Microorganisms beyond H. pylori and Epstein-Barr Virus.

While previous research has primarily focused on the impact of H. pylori and Epstein-Barr virus (EBV), emerging evidence suggests that other microbial influences, including viral and fungal infections, may also contribute to gastric cancer (GC) development. The intricate interactions between these microbes and the host's immune response provide a more comprehensive understanding of gastric cancer pathogenesis, diagnosis, and treatment. The review highlights the roles of established players such as H. pylori and EBV and the potential impacts of gut bacteria, mainly Lactobacillus, Streptococcus, hepatitis B virus, hepatitis C virus, and fungi such as Candida albicans. Advanced sequencing technologies offer unprecedented insights into the complexities of the gastric microbiome, from microbial diversity to potential diagnostic applications. Furthermore, the review highlights the potential for advanced GC diagnosis and therapies through a better understanding of the gut microbiome.

MLK4 promotes glucose metabolism in lung adenocarcinoma through CREB-mediated activation of phosphoenolpyruvate carboxykinase and is regulated by KLF5.

MLK4, a member of the mitogen-activated protein kinase kinase kinase (MAP3K) family, has been implicated in cancer progression. However, its role in lung adenocarcinoma has not been characterized. Here, we showed that MLK4 was overexpressed in a significant subset of lung adenocarcinoma, associated with a worse prognosis, and exerted an oncogenic function in vitro and in vivo. Bioinformatics analyses of clinical datasets identified phosphoenolpyruvate carboxykinase 1 (PCK1) as a novel target of MLK4. We validated that MLK4 regulated PCK1 expression at transcriptional level, by phosphorylating the transcription factor CREB, which in turn mediated PCK1 expression. We further demonstrated that PCK1 is an oncogenic factor in lung adenocarcinoma. Given the importance of PCK1 in the regulation of cellular metabolism, we next deciphered the metabolic effects of MLK4. Metabolic and mass spectrometry analyses showed that MLK4 knockdown led to significant reduction of glycolysis and decreased levels of glycolytic pathway metabolites including phosphoenolpyruvate and lactate. Finally, the promoter analysis of MLK4 unravelled a binding site of transcription factor KLF5, which in turn, positively regulated MLK4 expression in lung adenocarcinoma. In summary, we have revealed a KLF5-MLK4-PCK1 signalling pathway involved in lung tumorigenesis and established an unusual link between MAP3K signalling and cancer metabolism.

The E2F1-HOXB9/PBX2-CDK6 axis drives gastric tumorigenesis and serves as a therapeutic target in gastric cancer.

Homeobox genes include HOX and non-HOX genes. HOX proteins play fundamental roles during ontogenesis by interacting with other non-HOX gene-encoded partners and performing transcriptional functions, whereas aberrant activation of HOX family members drives tumorigenesis. In this study, gastric cancer (GC) expression microarray data indicated that HOXB9 is a prominent upregulated HOX member in GC samples significantly associated with clinical outcomes and advanced TNM stages. However, the functional role of HOXB9 in GC remains contradictory in previous reports, and the regulatory mechanisms are elusive. By in silico and experimental analyses, we found that HOXB9 was upregulated by a vital cell cycle-related transcription factor, E2F1. Depleting HOXB9 causes G1-phase cell cycle arrest by downregulating CDK6 and a subset of cell cycle-related genes. Meanwhile, HOXB9 contributes to cell division and maintains the cytoskeleton in GC cells. We verified that HOXB9 interacts with PBX2 to form a heterodimer, which transcriptionally upregulates CDK6. Knocking down CDK6 can phenocopy the tumor-suppressive effects caused by HOXB9 depletion. Blocking HOXB9 can enhance the anti-tumor effect of CDK6 inhibitors. In conclusion, we elucidate the oncogenic role of HOXB9 in GC and reveal CDK6 as its potent downstream effector. The E2F1-HOXB9/PBX2-CDK6 axis represents a novel mechanism driving gastric carcinogenesis and conveys prognostic and therapeutic implications. © 2023 The Pathological Society of Great Britain and Ireland.

Frequency of Peripheral CD8+ T Cells Expressing Chemo-Attractant Receptors CCR1, 4 and 5 Increases in NPC Patients with EBV Clearance upon Radiotherapy.

Radiotherapy (RT) is the standard-of-care for Epstein-Barr virus (EBV)-associated nasopharyngeal carcinoma (NPC), where the post-RT clearance of plasma EBV DNA is prognostic. Currently, it is not known whether the post-RT clearance of plasma EBV DNA is related to the presence of circulating T-cell subsets. Blood samples from NPC patients were used to assess the frequency of T-cell subsets relating to differentiation, co-signaling and chemotaxis. Patients with undetectable versus detectable plasma EBV DNA levels post-RT were categorized as clearers vs. non-clearers. Clearers had a lower frequency of PD1+CD8+ T cells as well as CXCR3+CD8+ T cells during RT compared to non-clearers. Clearers exclusively showed a temporal increase in chemo-attractant receptors CCR1, 4 and/or 5, expressing CD8+ T cells upon RT. The increase in CCR-expressing CD8+ T cells was accompanied by a drop in naïve CD8+ T cells and an increase in OX40+CD8+ T cells. Upon stratifying these patients based on clinical outcome, the dynamics of CCR-expressing CD8+ T cells were in concordance with the non-recurrence of NPC. In a second cohort, non-recurrence associated with higher quantities of circulating CCL14 and CCL15. Collectively, our findings relate plasma EBV DNA clearance post-RT to T-cell chemotaxis, which requires validation in larger cohorts.

An Update of G-Protein-Coupled Receptor Signaling and Its Deregulation in Gastric Carcinogenesis.

G-protein-coupled receptors (GPCRs) belong to a cell surface receptor superfamily responding to a wide range of external signals. The binding of extracellular ligands to GPCRs activates a heterotrimeric G protein and triggers the production of numerous secondary messengers, which transduce the extracellular signals into cellular responses. GPCR signaling is crucial and imperative for maintaining normal tissue homeostasis. High-throughput sequencing analyses revealed the occurrence of the genetic aberrations of GPCRs and G proteins in multiple malignancies. The altered GPCRs/G proteins serve as valuable biomarkers for early diagnosis, prognostic prediction, and pharmacological targets. Furthermore, the dysregulation of GPCR signaling contributes to tumor initiation and development. In this review, we have summarized the research progress of GPCRs and highlighted their mechanisms in gastric cancer (GC). The aberrant activation of GPCRs promotes GC cell proliferation and metastasis, remodels the tumor microenvironment, and boosts immune escape. Through deep investigation, novel therapeutic strategies for targeting GPCR activation have been developed, and the final aim is to eliminate GPCR-driven gastric carcinogenesis.

Latent membrane protein 1 and macrophage-derived TNFα synergistically activate and mobilize invadopodia to drive invasion of nasopharyngeal carcinoma.

Invadopodia are actin-rich membrane protrusions that digest the matrix barrier during cancer metastasis. Since the discovery of invadopodia, they have been visualized as localized and dot-like structures in different types of cancer cells on top of a 2D matrix. In this investigation of Epstein-Barr virus (EBV)-associated nasopharyngeal carcinoma (NPC), a highly invasive cancer frequently accompanied by neck lymph node and distal organ metastases, we revealed a new form of invadopodium with mobilizing features. Integration of live-cell imaging and molecular assays revealed the interaction of macrophage-released TNFα and EBV-encoded latent membrane protein 1 (LMP1) in co-activating the EGFR/Src/ERK/cortactin and Cdc42/N-WASP signaling axes for mobilizing the invadopodia with lateral movements. This phenomenon endows the invadopodia with massive degradative power, visualized as a shift of focal dot-like digestion patterns on a 2D gelatin to a dendrite-like digestion pattern. Notably, single stimulation of either LMP1 or TNFα could only enhance the number of ordinary dot-like invadopodia, suggesting that the EBV infection sensitizes the NPC cells to form mobilizing invadopodia when encountering a TNFα-rich tumor microenvironment. This study unveils the interplay of EBV and stromal components in driving the invasive potential of NPC via unleashing the propulsion of invadopodia in overcoming matrix hurdles. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Cancer-associated fibroblasts potentiate colorectal cancer progression by crosstalk of the IGF2-IGF1R and Hippo-YAP1 signaling pathways.

Colorectal cancer (CRC) is one of the most common cancers worldwide. The tumor microenvironment exerts crucial effects in driving CRC progression. Cancer-associated fibroblasts (CAFs) serve as one of the most important tumor microenvironment components promoting CRC progression. This study aimed to elucidate the novel molecular mechanisms of CAF-secreted insulin-like growth factor (IGF) 2 in colorectal carcinogenesis. Our results indicated that IGF2 was a prominent factor upregulated in CAFs compared with normal fibroblasts. CAF-derived conditioned media (CM) promoted tumor growth, migration, and invasion of HCT 116 and DLD-1 cells. IGF1R expression is significantly increased in CRC, serving as a potent receptor in response to IGF2 stimulation and predicting unfavorable outcomes for CRC patients. Apart from the PI3K-AKT pathway, RNA-seq analysis revealed that the YAP1-target signature serves as a prominent downstream effector to mediate the oncogenic signaling of IGF2-IGF1R. By single-cell RNA sequencing (scRNA-seq) and immunohistochemical validation, IGF2 was found to be predominantly secreted by CAFs, whereas IGF1R was expressed mainly by cancer cells. IGF2 triggers the nuclear accumulation of YAP1 and upregulates YAP1 target signatures; however, these effects were abolished by either IGF1R knockdown or inhibition with picropodophyllin (PPP), an IGF1R inhibitor. Using CRC organoid and in vivo studies, we found that cotargeting IGF1R and YAP1 with PPP and verteporfin (VP), a YAP1 inhibitor, enhanced antitumor effects compared with PPP treatment alone. In conclusion, this study revealed a novel molecular mechanism by which CAFs promote CRC progression. The findings highlight the translational potential of the IGF2-IGF1R-YAP1 axis as a prognostic biomarker and therapeutic target for CRC. © 2022 The Pathological Society of Great Britain and Ireland.

Targeting YAP1/TAZ in nonsmall-cell lung carcinoma: From molecular mechanisms to precision medicine.

Accumulating evidence has underscored the importance of the Hippo-YAP1 signaling in lung tissue homeostasis, whereas its deregulation induces tumorigenesis. YAP1 and its paralog TAZ are the key downstream effectors tightly controlled by the Hippo pathway. YAP1/TAZ exerts oncogenic activities by transcriptional regulation via physical interaction with TEAD transcription factors. In solid tumors, Hippo-YAP1 crosstalks with other signaling pathways such as Wnt/ß-catenin, receptor tyrosine kinase cascade, Notch and TGF-ß to synergistically drive tumorigenesis. As YAP1/TAZ expression is significantly correlated with unfavorable outcomes for the patients, small molecules have been developed for targeting YAP1/TAZ to get a therapeutic effect. In this review, we summarize the recent findings on the deregulation of Hippo-YAP1 pathway in nonsmall cell lung carcinoma, discuss the molecular mechanisms of its dysregulation in leading to tumorigenesis, explore the therapeutic strategies for targeting YAP1/TAZ, and provide the research directions for deep investigation. We believe that detailed delineation of Hippo-YAP1 regulation in tumorigenesis provides novel insight for accurate therapeutic intervention.

Accurate identification of structural variations from cancer samples.

Structural variations (SVs) are commonly found in cancer genomes. They can cause gene amplification, deletion and fusion, among other functional consequences. With an average read length of hundreds of kilobases, nano-channel-based optical DNA mapping is powerful in detecting large SVs. However, existing SV calling methods are not tailored for cancer samples, which have special properties such as mixed cell types and sub-clones. Here we propose the Cancer Optical Mapping for detecting Structural Variations (COMSV) method that is specifically designed for cancer samples. It shows high sensitivity and specificity in benchmark comparisons. Applying to cancer cell lines and patient samples, COMSV identifies hundreds of novel SVs per sample.

MCM6 is a critical transcriptional target of YAP to promote gastric tumorigenesis and serves as a therapeutic target.

Rationale: Hyperactivation of Hippo-Yes-associated protein (YAP) signaling pathway governs tumorigenesis of gastric cancer (GC). Here we reveal that minichromosome maintenance complex component 6 (MCM6) is a critical transcriptional target of YAP in GC. We aim to investigate the function, mechanism of action, and clinical implication of MCM6 in GC. Methods: The downstream targets of YAP were screened by RNA sequencing (RNA-seq) and microarray, and further validated by chromatin immunoprecipitation PCR and luciferase reporter assays. The clinical implication of MCM6 was assessed in multiple GC cohorts. Biological function of MCM6 was evaluated in vitro, in patient-derived organoids, and in vivo. RNA-seq was performed to unravel downstream signaling of MCM6. Potential MCM6 inhibitor was identified and the effect of MCM6 inhibition on GC growth was evaluated. Results: Integrative RNA sequencing and microarray analyses revealed MCM6 as a potential YAP downstream target in GC. The YAP-TEAD complex bound to the promoter of MCM6 to induce its transcription. Increased MCM6 expression was commonly observed in human GC tissues and predicted poor patients survival. MCM6 knockdown suppressed proliferation and migration of GC cells and patient-derived organoids, and attenuated xenograft growth and peritoneal metastasis in mice. Mechanistically, MCM6 activated PI3K/Akt/GSK3ß signaling to support YAP-potentiated gastric tumorigenicity and metastasis. Furthermore, MCM6 deficiency sensitized GC cells to chemo- or radiotherapy by causing DNA breaks and blocking ATR/Chk1-mediated DNA damage response (DDR), leading to exacerbated cell death and tumor regression. As there are no available MCM6 inhibitors, we performed high-throughput virtual screening and identified purpureaside C as a novel MCM6 inhibitor. Purpureaside C not only suppressed GC growth but also synergized with 5-fluorouracil to induce cell death. Conclusions: Hyperactivated YAP in GC induces MCM6 transcription via binding to its promoter. YAP-MCM6 axis facilitates GC progression by inducing PI3K/Akt signaling. Targeting MCM6 suppresses GC growth and sensitizes GC cells to genotoxic agents by modulating ATR/Chk1-dependent DDR, providing a promising strategy for GC treatment.

The CBP/ß-Catenin Antagonist, ICG-001, Inhibits Tumor Metastasis via Blocking of the miR-134/ITGB1 Axis-Mediated Cell Adhesion in Nasopharyngeal Carcinoma.

Nasopharyngeal carcinoma (NPC) is an Epstein-Barr virus (EBV)-associated malignancy ranking as the 23rd most common cancer globally, while its incidence rate ranked the 9th in southeast Asia. Tumor metastasis is the dominant cause for treatment failure in NPC and metastatic NPC is yet incurable. The Wnt/ß-catenin signaling pathway plays an important role in many processes such as cell proliferation, differentiation, epithelial-mesenchymal transition (EMT), and self-renewal of stem cells and cancer stem cells (CSCs). Both the EMT process and CSCs are believed to play a critical role in cancer metastasis. We here investigated whether the specific CBP/ß-catenin Wnt antagonist, IGC-001, affects the metastasis of NPC cells. We found that ICG-001 treatment could reduce the adhesion capability of NPC cells to extracellular matrix and to capillary endothelial cells and reduce the tumor cell migration and invasion, events which are closely associated with distant metastasis. Through a screening of EMT and CSC-related microRNAs, it was found that miR-134 was consistently upregulated by ICG-001 treatment in NPC cells. Very few reports have mentioned the functional role of miR-134 in NPC, except that the expression was found to be downregulated in NPC. Transient transfection of miR-134 into NPC cells reduced their cell adhesion, migration, and invasion capability, but did not affect the growth of CSC-enriched tumor spheres. Subsequently, we found that the ICG-001-induced miR-134 expression resulting in downregulation of integrin ß1 (ITGB1). Such downregulation reduced cell adhesion and migration capability, as demonstrated by siRNA-mediated knockdown of ITGB1. Direct targeting of ITGB1 by miR-134 was confirmed by the 3'-UTR luciferase assay. Lastly, using an in vivo lung metastasis assay, we showed that ICG-001 transient overexpression of miR-134 or stable overexpression of miR-134 could significantly reduce the lung metastasis of NPC cells. Taken together, we present here evidence that modulation of Wnt/ß-catenin signaling pathway could inhibit the metastasis of NPC through the miR-134/ITGB1 axis.

Accurate reconstruction of viral genomes in human cells from short reads using iterative refinement.

BACKGROUND: After an infection, human cells may contain viral genomes in the form of episomes or integrated DNA. Comparing the genomic sequences of different strains of a virus in human cells can often provide useful insights into its behaviour, activity and pathology, and may help develop methods for disease prevention and treatment. To support such comparative analyses, the viral genomes need to be accurately reconstructed from a large number of samples. Previous efforts either rely on customized experimental protocols or require high similarity between the sequenced genomes and a reference, both of which limit the general applicability of these approaches. In this study, we propose a pipeline, named ASPIRE, for reconstructing viral genomes accurately from short reads data of human samples, which are increasingly available from genome projects and personal genomics. ASPIRE contains a basic part that involves de novo assembly, tiling and gap filling, and additional components for iterative refinement, sequence corrections and wrapping. RESULTS: Evaluated by the alignment quality of sequencing reads to the reconstructed genomes, these additional components improve the assembly quality in general, and in some particular samples quite substantially, especially when the sequenced genome is significantly different from the reference. We use ASPIRE to reconstruct the genomes of Epstein Barr Virus (EBV) from the whole-genome sequencing data of 61 nasopharyngeal carcinoma (NPC) samples and provide these sequences as a resource for EBV research. CONCLUSIONS: ASPIRE improves the quality of the reconstructed EBV genomes in published studies and outperforms TRACESPipe in some samples considered.