The Hippo signaling pathway in gastric cancer

Metallothionein 2A enhances the yes-associated protein 1 signaling pathway to promote small-cell lung cancer metastasis

Objective

Small-cell lung cancer (SCLC) remains challenging to treat due to its high invasiveness and propensity for drug resistance. Evidence suggests that the regulatory relationship between metallothionein 2A (MT2A) and the yes-associated protein 1 (YAP1) signaling pathway may influence the development of SCLC. Therefore, this study aims to explore the potential mechanisms affecting SCLC progression based on the regulatory interaction between YAP1 and MT2A.

Material and Methods

This study utilized reverse transcription quantitative polymerase chain reaction and Western blot analysis to analyze MT2A expression in cells. SCLC cell models with MT2A silencing and overexpression, as well as cotransfected cell models with YAP1 silencing and MT2A overexpression, were constructed. The effect of MT2A/YAP1 on cell growth, migration, and invasion was evaluated through a series of experiments, including cell viability assessment using cell counting kit-8 assay, colony formation examination, 5-ethynyl-2'-deoxyuridine staining, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling staining, and Transwell analysis. In addition, Western blot analysis was conducted to investigate alterations in crucial proteins associated with the YAP1 pathway and the epithelial-mesenchymal transition ( EMT) markers influenced by MT2A/YAP1. Lung metastasis and Ki67 expression were analyzed through hematoxylin and eosin staining and immunofluorescence analysis in vivo.

Results

In the SCLC cell line ( NCI-H69 cells), MT2A exhibits increased expression, facilitating cell growth, migration, and invasion. YAP1 expression decreases when MT2A is depleted. In addition, our findings validate that MT2A facilitates EMT progression and SCLC invasion and metastasis by upregulating YAP1 expression. In vitro, silencing MT2A inhibits lung metastasis and Ki67 expression.

Conclusion

MT2A facilitates the migration and invasion of SCLC cells by influencing the YAP1 signaling cascade. This investigation offers a fresh avenue for delving deeply into the potential mechanisms involved in the progression of SCLC.

Protein Coronation-Induced Cancer Staging-Dependent Multilevel Cytotoxicity: An All-Humanized Study in Blood Vessel Organoids

The protein corona effect refers to the phenomenon wherein nanomaterials in the bloodstream are coated by serum proteins, yet how protein coronated nanomaterials interact with blood vessels and its toxicity implications remain poorly understood. In this study, we investigated protein corona-related vessel toxicity by using an all-humanized assay integrating blood vessel organoids and patient-derived serum. Initially, we screened various nanomaterials to discern how parameters including size, morphology, hydrophobicity, surface charge, and chirality-dependent protein corona difference influence their uptake by vessel organoids. For nanomaterials showing substantial differences in vessel uptake, their protein corona was analyzed by using label-free mass spectra. Our findings revealed the involvement of cancer staging-related cytoskeleton components in mediating preferential uptake by cells, including endothelial and mural cells. Additionally, a transcriptome study was conducted to elucidate the influence of nanomaterials. We confirmed that protein coronated nanomaterials provoke remodeling at both transcriptional and translational levels, impacting pathways such as PI3K-Akt/Hippo/Wnt, and membraneless organelle integrity, respectively. Our study further demonstrated that the remodeling potential of patient-derived protein coronated nanomaterials can be harnessed to synergize with antiangiogenesis therapeutics to improve the outcomes. We anticipate that this study will provide guidance for the safe use of nanomedicine in the future.

Epstein-Barr virus infection upregulates extracellular OLFM4 to activate YAP signaling during gastric cancer progression

Extracellular vesicles (EVs) are known to mediate cell communications and shape tumor microenvironment. Compared to the well-studied small EVs, the function of large microvesicles (MVs) during tumorigenesis is poorly understood. Here we show the proteome of MVs in Epstein-Barr virus (EBV)-associated gastric cancer (EBVaGC), and identify olfactomedin 4 (OLFM4) is induced by EBV infection and secreted via MVs to promote tumor progression through Hippo signaling. Specifically, OLFM4 is a target gene of the cGAS-STING pathway, and EBV infection activates cGAS-STING pathway and increases OLFM4 expression. Moreover, MV-carried OLFM4 binds with the extracellular cadherin domain of FAT1, thereby impairing its intracellular interaction with MST1 and leading to YAP activation in recipient cells. Together, our study not only reveals a regulatory mechanism though which viral infection is coupled via MVs with intercellular control of the Hippo signaling, but also highlights the OLFM4-Hippo axis as a therapeutic target for EBV-associated cancers.

Roles of deubiquitinases in urologic cancers (Review)

Human health is endangered by the occurrence and progression of urological cancers, including renal cell carcinoma, prostate cancer and bladder cancer, which are usually associated with the activation of oncogenic factors and inhibition of cancer suppressors. The primary mechanism for protein breakdown in cells is the ubiquitin-proteasome system, whilst deubiquitinases contribute to the reversal of this process. However, both are important for protein homeostasis. Deubiquitination may also be involved in the control of the cell cycle, proliferation and apoptosis, and dysregulated deubiquitination is associated with the malignant transformation, invasion and metastasis of urologic malignancies. Therefore, a comprehensive summary of the mechanisms underlying deubiquitination in urological cancers may provide novel strategies and insights for diagnosis and treatment. The present review aimed to methodically clarify the role of deubiquitinating enzymes in urinary system cancers as well as their prospective application prospects for clinical treatment.

ZC3H13 knockdown enhances the inhibitory effect of sevoflurane on gastric cancer cell malignancy by regulating the N6-methyladenosine modification of the lncRNA DLX6-AS1

Sevoflurane, an inhalation anesthetic, has been shown to suppress cancer development. In this study, we investigated the specific mechanisms involving sevoflurane, zinc-finger CCCH-type containing 13 (ZC3H13), and lncRNA DLX6-AS1 in gastric cancer (GC) progression, focusing on the N6-methyladenosine (m6A) modification of long non-coding RNAs (lncRNAs). We used quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot analyses to measure the levels of ZC3H13 and lncRNA DLX6-AS1 in GC tissues and cells. Furthermore, we conducted Cell Counting Kit-8, colony formation, Transwell, and tumor xenograft assays to evaluate changes in GC cell malignancy following cell transfection and sevoflurane treatment. Additionally, actinomycin D, methylated RNA immunoprecipitation, and qRT-PCR assays were performed to examine the regulatory effects of ZC3H13 on the DLX6-AS1 m6A modification. We detected elevated levels of ZC3H13 in GC samples, while ZC3H13 silencing inhibited GC cell proliferation, migration, and invasion. Silencing ZC3H13 also enhanced the inhibitory effects of sevoflurane on GC cell malignancy. Moreover, we found that the increased expression of DLX6-AS1 in GC cells could be suppressed by ZC3H13 through the mediation of the m6A modification of DLX6-AS1, thereby reducing DLX6-AS1 stability. In conclusion, ZC3H13 knockdown enhances the inhibitory effect of sevoflurane on GC cell malignancy by inducing DLX6-AS1 m6A modification. Our findings may help identify potential therapeutic targets for the treatment of GC.

Modeling human gastric cancers in immunocompetent mice

Gastric cancer (GC) is a major cause of cancer-related mortality worldwide. GC is determined by multiple (epi)genetic and environmental factors; can occur at distinct anatomic positions of the stomach; and displays high heterogeneity, with different cellular origins and diverse histological and molecular features. This heterogeneity has hindered efforts to fully understand the pathology of GC and develop efficient therapeutics. In the past decade, great progress has been made in the study of GC, particularly in molecular subtyping, investigation of the immune microenvironment, and defining the evolutionary path and dynamics. Preclinical mouse models, particularly immunocompetent models that mimic the cellular and molecular features of human GC, in combination with organoid culture and clinical studies, have provided powerful tools for elucidating the molecular and cellular mechanisms underlying GC pathology and immune evasion, and the development of novel therapeutic strategies. Herein, we first briefly introduce current progress and challenges in GC study and subsequently summarize immunocompetent GC mouse models, emphasizing the potential application of genetically engineered mouse models in antitumor immunity and immunotherapy studies.

FANCA facilitates G1/S cell cycle advancement, proliferation, migration and invasion in gastric cancer

The present study explores the function of FANCA gene, a pivotal member of the Fanconi anaemia (FA) pathway crucial for preserving genomic stability and preventing cancer, particularly in the context of gastric cancer (GC). Using immunohistochemistry, quantitative real-time PCR, and western blot analysis, we evaluate FANCA mRNA and protein expressions in GC cell lines. The relationship between FANCA expression and clinicopathological characteristics is also explored. Various assays, including CCK8, colony formation, wound healing, and Transwell assays, are used to assess functional changes in cells associated with FANCA. Flow cytometry is utilized to evaluate alterations in the cell cycle resulted from FANCA knockdown and overexpression. Our findings show elevated FANCA expression in GC cell lines, with levels correlated with pathologic stage and lymphatic metastasis. FANCA knockdown impedes cell proliferation, migration, and invasion and induces G1/S phase cell cycle arrest. Conversely, FANCA overexpression stimulates cell proliferation, migration, and invasion. In vivo xenograft experiments confirm the promotional role of FANCA in GC tumor progression. Moreover, FANCA overexpression is associated with the activation of cell cycle. Collectively, our results suggest that FANCA drives malignant cell behaviors in GC through the cell cycle pathway, highlighting its potential as a therapeutic target for the treatment of GC.

Inflammatory microenvironment in gastric premalignant lesions: implication and application

Gastric precancerous lesions (GPL) are a major health concern worldwide due to their potential to progress to gastric cancer (GC). Understanding the mechanism underlying the transformation from GPL to GC can provide a fresh insight for the early detection of GC. Although chronic inflammation is prevalent in the GPL, how the inflammatory microenvironment monitored the progression of GPL-to-GC are still elusive. Inflammation has been recognized as a key player in the progression of GPL. This review aims to provide an overview of the inflammatory microenvironment in GPL and its implications for disease progression and potential therapeutic applications. We discuss the involvement of inflammation in the progression of GPL, highlighting Helicobacter pylori (H. pylori) as a mediator for inflammatory microenvironment and a key driver to GC progression. We explore the role of immune cells in mediating the progression of GPL, and focus on the regulation of inflammatory molecules in this disease. Furthermore, we discuss the potential of targeting inflammatory pathways for GPL. There are currently no specific drugs for GPL treatment, but traditional Chinese Medicine (TCM) and natural antioxidants, known as antioxidant and anti-inflammatory properties, exhibit promising effects in suppressing or reversing the progression of GPL. Finally, the challenges and future perspectives in the field are proposed. Overall, this review highlights the central role of the inflammatory microenvironment in the progression of GPL, paving the way for innovative therapeutic approaches in the future.

Regulation of the Hippo/YAP axis by CXCR7 in the tumorigenesis of gastric cancer

BACKGROUND

The Hippo pathway is crucial in organ size control and tumorigenesis. Dysregulation of the Hippo/YAP axis is commonly observed in gastric cancer, while effective therapeutic targets for the Hippo/YAP axis are lacking. Identification of reliable drug targets and the underlying mechanisms that could inhibit the activity of the Hippo/YAP axis and gastric cancer progression is urgently needed.

METHODS

We used several gastric cancer cell lines and xenograft models and performed immunoblotting, qPCR, and in vivo studies to investigate the function of CXCR7 in gastric cancer progression.

RESULTS

In our current study, we demonstrate that the membrane receptor CXCR7 (C-X-C chemokine receptor 7) is an important modulator of the Hippo/YAP axis. The activation of CXCR7 could stimulate gastric cancer cell progression through the Hippo/YAP axis in vitro and in vivo, while pharmaceutical inhibition of CXCR7 via ACT-1004-1239 could block tumorigenesis in gastric cancer. Molecular studies revealed that the activation of CXCR7 could dephosphorylate YAP and facilitate YAP nuclear accumulation and transcriptional activation in gastric cancer. CXCR7 functions via G-protein Gαq/11 and Rho GTPase to activate YAP activity. Interestingly, ChIP assays showed that YAP could bind to the promoter region of CXCR7 and facilitate its gene transcription, which indicates that CXCR7 is both the upstream signalling and downstream target of the Hippo/YAP axis in gastric cancer.

CONCLUSION

In general, we identified a novel positive feedback loop between CXCR7 and the Hippo/YAP axis, and blockade of CXCR7 could be a plausible strategy for gastric cancer.