AQP9-induced cell cycle arrest is associated with RAS activation and improves chemotherapy treatment efficacy in colorectal cancer

Alteration of Hepatic Cytochrome P450 Expression and Arachidonic Acid Metabolism by Arsenic Trioxide (ATO) in C57BL/6 Mice

The success of arsenic trioxide (ATO) in acute promyelocytic leukemia has driven a plethora studies to investigate its efficacy in other malignancies. However, the inherent toxicity of ATO limits the expansion of its clinical applications. Such toxicity may be linked to ATO-induced metabolic derangements of endogenous substrates. Therefore, the primary objective of this study was to investigate the effect of ATO on the hepatic formation of arachidonic acid (AA) metabolites, hydroxyeicosatetraenoic acids (HETEs), as well as their most notable producing machinery, cytochrome P450 (CYP) enzymes. For this purpose, C57BL/6 mice were intraperitoneally injected with 8 mg/kg ATO for 6 and 24 h. Total RNA was extracted from harvested liver tissues for qPCR analysis of target genes. Hepatic microsomal proteins underwent incubation with AA, followed by identification/quantification of the produced HETEs. ATO downregulated Cyp2e1, while induced Cyp2j9 and most of Cyp4a and Cyp4f, and this has resulted in a significant increase in 17(S)-HETE and 18(R)-HETE, while significantly decreased 18(S)-HETE. Additionally, ATO induced Cyp4a10, Cyp4a14, Cyp4f13, Cyp4f16, and Cyp4f18, resulting in a significant elevation in 20-HETE formation. In conclusion, ATO altered hepatic AA metabolites formation through modulating the underlying network of CYP enzymes. Modifying the homeostatic production of bioactive AA metabolites, such as HETEs, may entail toxic events that can, at least partly, explain ATO-induced hepatotoxicity. Such modification can also compromise the overall body tolerability to ATO treatment in cancer patients.

The Involvement of Peroxiporins and Antioxidant Transcription Factors in Breast Cancer Therapy Resistance

Breast cancer is still the leading cause of death in women of all ages. The reason for this is therapy resistance, which leads to the progression of the disease and the formation of metastases. Multidrug resistance (MDR) is a multifactorial process that leads to therapy failure. MDR involves multiple processes and many signaling pathways that support each other, making it difficult to overcome once established. Here, we discuss cellular-oxidative-stress-modulating factors focusing on transcription factors NRF2, FOXO family, and peroxiporins, as well as their possible contribution to MDR. This is significant because oxidative stress is a consequence of radiotherapy, chemotherapy, and immunotherapy, and the activation of detoxification pathways could modulate the cellular response to therapy and could support MDR. These proteins are not directly responsible for MDR, but they support the survival of cancer cells under stress conditions.

Aquaporin 9 is involved in CRC metastasis through DVL2-dependent Wnt/β-catenin signaling activation

Background

Aquaporin 9 (AQP9) is permeable to water or other small molecules, and plays an important role in various cancers. We previously found that AQP9 was related to the efficacy of chemotherapy in patients with colorectal cancer (CRC). This study aimed to identify the role and regulatory mechanism of AQP9 in CRC metastasis.

Methods

The clinical significance of AQP9 was analysed by using bioinformatics and tissue microarray. Transcriptome sequencing, Dual-Luciferase Reporter Assay, Biacore, and co-immunoprecipitation were employed to demonstrate the regulatory mechanism of AQP9 in CRC. The relationship between AQP9 and CRC metastasis was verified in vitro and in vivo by using real-time cell analysis assay, high content screening, and liver metastasis models of nude mice.

Results

We found that AQP9 was highly expressed in metastatic CRC. AQP9 overexpression reduced cell roundness and enhanced cell motility in CRC. We further showed that AQP9 interacted with Dishevelled 2 (DVL2) via the C-terminal SVIM motif, resulting in DVL2 stabilization and the Wnt/β-catenin pathway activation. Additionally, we identified the E3 ligase neural precursor cell expressed developmentally downregulated 4-like (NEDD4L) as a modulator regulating the ubiquitination and degradation of AQP9.

Conclusions

Collectively, our study revealed the important role of AQP9 in regulating DVL2 stabilization and Wnt/β-catenin signaling to promote CRC metastasis. Targeting the NEDD4L-AQP9-DVL2 axis might have therapeutic usefulness in metastatic CRC treatment.

Identification of Specific Biomarkers and Pathways in the Treatment Response of Infliximab for Inflammatory Bowel Disease: In-Silico Analysis

Background: Inflammatory bowel disease (IBD) is characterized by chronic inflammation of the gastrointestinal tract. In biological therapy, infliximab became the first anti-tumor necrosis factor (TNF) agent approved for IBD. Despite this success, infliximab is expensive, often ineffective, and associated with adverse events. Prediction of infliximab resistance would improve overall potential outcomes. Therefore, there is a pressing need to widen the scope of investigating the role of genetics in IBD to their association with therapy response. Methods: In the current study, an in-silico analysis of publicly available IBD patient transcriptomics datasets from Gene Expression Omnibus (GEO) are used to identify subsets of differentially expressed genes (DEGs) involved in the pathogenesis of IBD and may serve as potential biomarkers for Infliximab response. Five datasets were found that met the inclusion criteria. The DEGs for datasets were identified using limma R packages through the GEOR2 tool. The probes’ annotated genes in each dataset intersected with DGEs from all other datasets. Enriched gene Ontology Clustering for the identified genes was performed using Metascape to explore the possible connections or interactions between the genes. Results: 174 DEGs between IBD and healthy controls were found from analyzing two datasets (GSE14580 and GSE73661), indicating a possible role in the pathogenesis of IBD. Of the 174 DEGs, five genes (SELE, TREM1, AQP9, FPR2, and HCAR3) were shared between all five datasets. Moreover, these five genes were identified as downregulated in the infliximab responder group compared to the non-responder group. Conclusions: We hypothesize that alteration in the expression of these genes leads to an impaired response to infliximab in IBD patients. Thus, these genes can serve as potential biomarkers for the early detection of compromised infliximab response in IBD patients.

Integrated multiple microarray studies by robust rank aggregation to identify immune-associated biomarkers in Crohn's disease based on three machine learning methods

Crohn's disease (CD) is a complex autoimmune disorder presumed to be driven by complex interactions of genetic, immune, microbial and even environmental factors. Intrinsic molecular mechanisms in CD, however, remain poorly understood. The identification of novel biomarkers in CD cases based on larger samples through machine learning approaches may inform the diagnosis and treatment of diseases. A comprehensive analysis was conducted on all CD datasets of Gene Expression Omnibus (GEO); our team then used the robust rank aggregation (RRA) method to identify differentially expressed genes (DEGs) between controls and CD patients. PPI (protein‒protein interaction) network and functional enrichment analyses were performed to investigate the potential functions of the DEGs, with molecular complex detection (MCODE) identifying some important functional modules from the PPI network. Three machine learning algorithms, support vector machine-recursive feature elimination (SVM-RFE), random forest (RF), and least absolute shrinkage and selection operator (LASSO), were applied to determine characteristic genes, which were verified by ROC curve analysis and immunohistochemistry (IHC) using clinical samples. Univariable and multivariable logistic regression were used to establish a machine learning score for diagnosis. Single-sample GSEA (ssGSEA) was performed to examine the correlation between immune infiltration and biomarkers. In total, 5 datasets met the inclusion criteria: GSE75214, GSE95095, GSE126124, GSE179285, and GSE186582. Based on RRA integrated analysis, 203 significant DEGs were identified (120 upregulated genes and 83 downregulated genes), and MCODE revealed some important functional modules in the PPI network. Machine learning identified LCN2, REG1A, AQP9, CCL2, GIP, PROK2, DEFA5, CXCL9, and NAMPT; AQP9, PROK2, LCN2, and NAMPT were further verified by ROC curves and IHC in the external cohort. The final machine learning score was defined as [Expression level of AQP9 × (2.644)] + [Expression level of LCN2 × (0.958)] + [Expression level of NAMPT × (1.115)]. ssGSEA showed markedly elevated levels of dendritic cells and innate immune cells, such as macrophages and NK cells, in CD, consistent with the gene enrichment results that the DEGs are mainly involved in the IL-17 signaling pathway and humoral immune response. The selected biomarkers analyzed by the RRA method and machine learning are highly reliable. These findings improve our understanding of the molecular mechanisms of CD pathogenesis.

The Association Between Genetic Polymorphisms of Transporter Genes and Prognosis of Platinum-Based Chemotherapy in Lung Cancer Patients

Objective

Platinum-based chemotherapy is the first-line treatment of lung cancer. However, different individual and genetic variation effect therapy for lung cancer. The purpose of this study was to evaluate the association between transport genes genetic polymorphisms and the prognosis of platinum-based chemotherapy in lung cancer patients.

Methods

A series of 593 patients with treatment of platinum-based chemotherapy were recruited for this study. A total of 21 single-nucleotide polymorphisms in nine transporter genes were selected to investigate their associations with platinum-based chemotherapy prognosis.

Results

Patients with ABCG2 rs1448784 CC genotype had a significantly shorter PFS than CT or TT genotypes (Additive model: HR = 1.54, 95% CI = 1.02–2.35, P = 0.040). In stratification analysis, SLC22A2 rs316003, SLC2A1 rs4658 were related to PFS and AQP9 rs1867380, SLC2A1 rs3820589, SLC22A2 rs316003 indicated were related to OS of platinum-based chemotherapy prognosis.

Conclusion

Genetic polymorphisms of rs1448784 in ABCG2 might be potential clinical marker for predicting the prognosis of lung cancer patients treated with platinum-based chemotherapy.

Clinical value and molecular mechanism of AQGPs in different tumors

Aquaglyceroporins (AQGPs), including AQP3, AQP7, AQP9, and AQP10, are transmembrane channels that allow small solutes across biological membranes, such as water, glycerol, H₂O₂, and so on. Increasing evidence suggests that they play critical roles in cancer. Overexpression or knockdown of AQGPs can promote or inhibit cancer cell proliferation, migration, invasion, apoptosis, epithelial-mesenchymal transition and metastasis, and the expression levels of AQGPs are closely linked to the prognosis of cancer patients. Here, we provide a comprehensive and detailed review to discuss the expression patterns of AQGPs in different cancers as well as the relationship between the expression patterns and prognosis. Then, we elaborate the relevance between AQGPs and malignant behaviors in cancer as well as the latent upstream regulators and downstream targets or signaling pathways of AQGPs. Finally, we summarize the potential clinical value in cancer treatment. This review will provide us with new ideas and thoughts for subsequent cancer therapy specifically targeting AQGPs.

The Multifaceted Role of Aquaporin-9 in Health and Its Potential as a Clinical Biomarker

Aquaporins (AQPs) are transmembrane channels essential for water, energy, and redox homeostasis, with proven involvement in a variety of pathophysiological conditions such as edema, glaucoma, nephrogenic diabetes insipidus, oxidative stress, sepsis, cancer, and metabolic dysfunctions. The 13 AQPs present in humans are widely distributed in all body districts, drawing cell lineage-specific expression patterns closely related to cell native functions. Compelling evidence indicates that AQPs are proteins with great potential as biomarkers and targets for therapeutic intervention. Aquaporin-9 (AQP9) is the most expressed in the liver, with implications in general metabolic and redox balance due to its aquaglyceroporin and peroxiporin activities, facilitating glycerol and hydrogen peroxide (H₂O₂) diffusion across membranes. AQP9 is also expressed in other tissues, and their altered expression is described in several human diseases, such as liver injury, inflammation, cancer, infertility, and immune disorders. The present review compiles the current knowledge of AQP9 implication in diseases and highlights its potential as a new biomarker for diagnosis and prognosis in clinical medicine.

AQP9 and ZAP70 as immune-related prognostic biomarkers suppress proliferation, migration and invasion of laryngeal cancer cells

BACKGROUND

Laryngeal cancer represents a common malignancy that originates from the larynx, with unfavorable prognosis. Herein, this study systematically analyzed the immune signatures of laryngeal cancer and to evaluate their roles on tumor progression.

METHODS

Differentially expressed immune-related genes (IRGs) were screened between laryngeal cancer and normal tissues from TCGA dataset. Then, two prognosis-related IRGs AQP9 and ZAP70 were analyzed by a series of survival analysis. Based on them, molecular subtypes were constructed by unsupervised cluster analysis. Differences in survival outcomes, HLA expression and immune cell infiltrations were assessed between subtypes. Expression of AQP9 and ZAP70 was validated in laryngeal cancer tissues and cells by RT-qPCR and immunohistochemistry. After silencing and overexpressing AQP9 and ZAP70, CCK-8, EdU, wound healing and transwell assays were performed in TU212 and LCC cells.

RESULTS

Totally, 315 IRGs were abnormally expressed in laryngeal cancer. Among them, AQP9 and ZAP70 were distinctly correlated to patients' prognosis. Two subtypes were developed with distinct survival outcomes, HLA expression and immune microenvironment. Low expression of AQP9 and ZAP70 was confirmed in laryngeal cancer. AQP9 and ZAP70 up-regulation distinctly suppressed proliferation, migration, and invasion of laryngeal cancer cells. The opposite results were investigated when their knockdown.

CONCLUSIONS

Our findings revealed the roles of AQP9 and ZAP70 in progression of laryngeal cancer, and suggested that AQP9 and ZAP70 could potentially act as candidate immunotherapeutic targets for laryngeal cancer.

Signaling Mechanisms and Pharmacological Modulators Governing Diverse Aquaporin Functions in Human Health and Disease

The aquaporins (AQPs) are a family of small integral membrane proteins that facilitate the bidirectional transport of water across biological membranes in response to osmotic pressure gradients as well as enable the transmembrane diffusion of small neutral solutes (such as urea, glycerol, and hydrogen peroxide) and ions. AQPs are expressed throughout the human body. Here, we review their key roles in fluid homeostasis, glandular secretions, signal transduction and sensation, barrier function, immunity and inflammation, cell migration, and angiogenesis. Evidence from a wide variety of studies now supports a view of the functions of AQPs being much more complex than simply mediating the passive flow of water across biological membranes. The discovery and development of small-molecule AQP inhibitors for research use and therapeutic development will lead to new insights into the basic biology of and novel treatments for the wide range of AQP-associated disorders.

LncRNA ENSG00000254615 Modulates Proliferation and 5-FU Resistance by Regulating p21 and Cyclin D1 in Colorectal Cancer

5-Fluorouracil (5-FU) resistance is an urgent problem of colorectal cancer (CRC) chemotherapy that needs to be resolved. To investigate 5-FU-associated lncRNAs for CRC might be of great significant. LncRNA ENSG00000254615 was detected by RNA-sequencing. ENSG00000254615 were detected highly expressed in 5-FU-sensitive CRC cells and tissue specimens, and inhibited cell proliferation and attenuated 5-FU resistance in vitro and in vivo. Furthermore, ENSG00000254615 participated in the regulation of p21 and Cyclin D1. Taken together, we proposed that ENSG00000254615 inhibits proliferation and attenuates 5-FU resistance of CRC by regulating p21 and Cyclin D1 expression.

Identification of a prognostic 4-mRNA signature in laryngeal squamous cell carcinoma

Background: Laryngeal squamous cell carcinoma (LSCC) is one of the most common malignancy in the respiratory tract and could reduce the quality of life seriously like dyspnea, dysphonia and dysphagia. Moreover, 5-year survival rate has decreased over the past 40 years. This study was designed to identify mRNAs that related to prognosis in LSCC to enable early detection and outcome improvement.

Methods: Gene expression profiles from Gene Expression Omnibus (GEO) (GSE59102, GSE84957) and The Cancer Genome Atlas (TCGA) were analyzed to identify differentially expressed genes (DEGs) with the help of bioinformatics tools. Functional enrichment analyses including Gene Ontology (GO) and pathway analysis were carried out to investigate the role of those genes and underlying molecular mechanisms in LSCC. Cox's regression analyses (univariate, LASSO and multivariate in order) were utilized to identify DEGs related with patients' overall survival and a 4-mRNA-based prognostic risk score model was established. Univariate and multivariate Cox's regression analyses were then performed on LSCC data (90 patients left) to identify independent predictors of OS, including the signature and clinicopathologic variables. The prognostic value of the gene signature was further validated and the genes were analyzed by GEPIA to get pan-cancer expression profiles.

Results: 444 differentially expressed mRNAs (250 up-regulated, 194 down-regulated) were identified based on the threshold of fold change > 2 and adjusted p value < 0.05. Univariate Cox's regression analysis showed that high risk score (HR: 3.056, 95% confidence interval [CI]: 0.135-0.649, p<0.001) and female (HR: 0.296, 95% CI: 2.020-4.624, p=0.002) were associated with relatively poor prognosis. Further multivariate Cox's regression analysis indicated that risk score and gender were independent prognostic factors (p<0.05). The risk score model could stratify patients into high- and low‑risk groups, which presents significantly differential overall survival (p= 8.252e-04). The AUCs of 1-, 3- and 5-year OS were 0.724, 0.783 and 0.818, respectively.

Conclusions: Our study provides evidence that the four-mRNA signature could serve as a biomarker to predict prognosis in LSCC, especially in long-term.

Analysis of Gastric Cancer Transcriptome Allows the Identification of Histotype Specific Molecular Signatures With Prognostic Potential

Gastric cancer is the fifth most common malignancy but the third leading cause of cancer-associated mortality worldwide. Therapy for gastric cancer remain largely suboptimal making the identification of novel therapeutic targets an urgent medical need. In the present study we have carried out a high-throughput sequencing of transcriptome expression in patients with gastric cancers. Twenty-four patients, among a series of 53, who underwent an attempt of curative surgery for gastric cancers in a single center, were enrolled. Patients were sub-grouped according to their histopathology into diffuse and intestinal types, and the transcriptome of the two subgroups assessed by RNAseq analysis and compared to the normal gastric mucosa. The results of this investigation demonstrated that the two histopathology phenotypes express two different patterns of gene expression. A total of 2,064 transcripts were differentially expressed between neoplastic and non-neoplastic tissues: 772 were specific for the intestinal type and 407 for the diffuse type. Only 885 transcripts were simultaneously differentially expressed by both tumors. The per pathway analysis demonstrated an enrichment of extracellular matrix and immune dysfunction in the intestinal type including CXCR2, CXCR1, FPR2, CARD14, EFNA2, AQ9, TRIP13, KLK11 and GHRL. At the univariate analysis reduced levels AQP9 was found to be a negative predictor of 4 years survival. In the diffuse type low levels CXCR2 and high levels of CARD14 mRNA were negative predictors of 4 years survival. In summary, we have identified a group of genes differentially regulated in the intestinal and diffuse histotypes of gastric cancers with AQP9, CARD14 and CXCR2 impacting on patients' prognosis, although CXCR2 is the only factor independently impacting overall survival.

Clinical implication of aquaporin 9 in non-small cell lung cancer patients: its expression and relationship with clinical features and prognosis

BACKGROUND

Aquaporin 9 (AQP9) is recognized as a key regulator in several cancers, whereas little is known about its clinical implication in non-small cell lung cancer (NSCLC). Thus, we aimed to explore AQP9 expression and its relationship with clinical features, prognosis in NSCLC patients.

METHODS

One hundred ninety-eight NSCLC patients who received resection were retrospectively enrolled. This study contained two cohorts: in cohort A, AQP9 protein expression (from formalin fixed paraffin embedded tumor and paired adjacent tissue specimens) in 198 patients was detected by immunohistochemistry (IHC). In cohort B, AQP9 mRNA expression (from fresh-frozen tumor and paired adjacent tissues) in 108 patients (out of 198 patients) was detected by RT-qPCR.

RESULTS

In cohort A, increased AQP9 IHC score and greater proportion of AQP9 protein high expression cases were shown in tumor tissue than adjacent tissue (both P < 0.001). Tumor AQP9 protein high expression correlated with lymph node (LYN) metastasis (P = 0.002) and raised TNM stage (P = 0.012). Interestingly, tumor AQP9 protein high expression related to worse disease-free survival (DFS) (P = 0.002) and overall survival (OS) (P = 0.026). In cohort B, AQP9 mRNA expression in tumor tissue was increased than adjacent tissue (P < 0.001), and tumor AQP9 mRNA high expression linked to LYN metastasis (P = 0.024) and increased TNM stage (P = 0.032) as well; tumor AQP9 mRNA high expression was related to shorter DFS (P = 0.009), and it presented with a trend to be correlated with worse OS (P = 0.054), but without statistical significance.

CONCLUSION

AQP9 serves as a potential indicator for monitoring disease progression and prognostication in NSCLC patients.

Prognostic Role of mRNA-Expression of Aquaporins (AQP) 3, 4, 7 and 9 in Stage pT1 Non-Muscle-Invasive Bladder Cancer

BACKGROUND: AQP proteins show a variety of functions in human cell metabolism. The role of different AQP subtypes in tumor metabolism and prognosis are subject of ongoing research. OBJECTIVE: To investigate the mRNA expression of Aquaporin (AQP) 3, 4, 7 and 9 in pT1 non-muscle-invasive bladder cancer (NMIBC) and its prognostic value in therapeutic decision making. METHODS: Formalin-fixed-paraffin-embedded (FFPE) tissues from transurethral resection of the bladder (TURB) from 112 patients with initial diagnosis of stage pT1 NMIBC were analyzed retrospectively together with clinical data and therapeutic approaches. mRNA expression of AQP3, 4, 7 and 9 was measured and quantified using RT-qPCR. RESULTS: Of the 112 patients (83.9%male, median age 72 years), 40 had a recurrence (35.7%), 16 a progression (14.3%) and 14 patients (12.5%) died tumor-related. mRNA expression for AQP3 was detected in 99.1%, AQP4 in 46.4%, AQP7 in 86.6%and AQP9 in 97.3%. Spearman analysis revealed statistically significant correlations between AQP3, AQP7 and AQP9 mRNA expression with adverse clinical and histopathological parameters (WHO1973 grade 3, concomitant Cis or multifocality). High AQP9 mRNA expression was associated with worse PFS in the total cohort (p = 0.034) and in Grade 3 tumors (p = 0.003) in Kaplan-Meier analysis. In patients with bladder sparing approach, high AQP3 mRNA expression was significantly associated with worse CSS in patients receiving BCG therapy (p = 0.029). CONCLUSIONS: mRNA expression of AQP3, 7 and 9 correlates with adverse clinical and pathological parameters. AQP3 and 9 may help to identify a subgroup of highest risk patients who may be considered for early cystectomy.

Genomic and expression characterization of aquaporin genes from Siniperca chuatsi

Aquaporins (AQPs) are major intrinsic proteins that form pores in the membranes of biological cells. We first cloned the full-length sequences of aqp0, 1, 3, 4, 7, 8, 9, 10, 11, and 12 genes in Siniperca chuatsi. The 10 S. chuatsi aqp (Sc-aqp) genes included complete open reading frames and exhibited different exon-intron organizations. Sc-aqp1, 3, 8, 9, 10, and 11 were mostly expressed in the gallbladder, gills, gastric cecum, liver, ovaries, and spleen, respectively; Sc-aqp0 and 4 were mostly expressed in larvae at 1 day after hatching and in gastrula; Sc-aqp7 and 12 were mostly expressed in 2K-cell embryos. The expression levels of Sc-aqp1, 3, 7, 8, 9, and 10 after 10 part per thousand (ppt) salt treatment had significantly changed compared with those after 0 ppt salt treatment. Real-time quantitative PCR analysis further showed that in the intestines, the mRNA levels of Sc-aqp1 and 10 significantly decreased by approximately 2.07- and 2.85-fold, respectively, whereas those of Sc-aqp8 and 9 significantly increased by approximately 7.08- and 4.14-fold, respectively. Sc-aqp1, 8, 9, and 10 showed no significant differences in the gills. Sc-aqp3 significantly decreased by approximately 1.51- and 1.67-fold in the gills and intestines, respectively. Sc-aqp7 significantly increased by approximately 4.18- and 7.04-fold in the gills and intestines, respectively. This study was the first to investigate the tissue expression profiles and response to salt stress of aqp genes in S. chuatsi. Moreover, altering diet and suffering from immune stress could cause changes in the expression level of aqps. This study provided valuable reference information for AQPs' roles in osmoregulation in freshwater fish.

Identification of a 14-Gene Prognostic Signature for Diffuse Large B Cell Lymphoma (DLBCL)

Although immunotherapy is a potential strategy to resist cancers, due to the inadequate acknowledge, this treatment is not always effective for diffuse large B cell lymphoma (DLBCL) patients. Based on the current situation, it is critical to systematically investigate the immune pattern. According to the result of univariate and multivariate cox proportional hazards, LASSO regression and Kaplan-Meier survival analysis on immune-related genes (IRGs), a prognostic signature, containing 14 IRGs (AQP9, LMBR1L, FGF20, TANK, CRP, ORM1, JAK1, BACH2, MTCP1, IFITM1, TNFSF10, FGF12, RFX5, and LAP3), was built. This model was validated by external data, and performed well. DLBCL patients were divided into low- and high-risk groups, according to risk scores from risk formula. The results of CIBERSORT showed that different immune status and infiltration pattern were observed in these two groups. Gene set enrichment analysis (GSEA) indicated 12 signaling pathways were significantly enriched in the high-risk group, such as natural killer cell-mediated cytotoxicity, toll-like receptor signaling pathway, and so on. In summary, 14 clinically significant IRGs were screened to build a risk score formula. This formula was an accurate tool to provide a certain basis for the treatment of DLBCL patients.

Long Non-coding RNA LINC00320 Inhibits Tumorigenicity of Glioma Cells and Angiogenesis Through Downregulation of NFKB1-Mediated AQP9

The inhibitory effect of long intergenic non-coding RNA 00320 (LINC00320) in glioma cell proliferation has been proposed in a recent study. However, the mechanisms by which LINC00320 regulate aquaporin 9 (AQP9) in glioma require further exploration. Hence, this study aims to investigate effects of LINC00320 on tumorigenicity of glioma cells and angiogenesis of microvascular endothelial cells (MVECs). Expression of LINC00320 and AQP9 in glioma tissues and cells was measured by reverse transcription–quantitative polymerase chain reaction and Western blot analysis. The relationship among LINC00320, nuclear factor κB subunit 1 (NFKB1) and AQP9 was examined by RNA immunoprecipitation, dual-luciferase reporter gene, and chromatin immunoprecipitation assays. The participation of LINC00320 and AQP9 in glioma cell proliferation and MVEC angiogenesis was analyzed using gain- and loss-of-function approaches. Finally, a nude mouse orthotopic xenograft model of glioma was established to investigate the effects of LINC00320 and AQP9 on glioma growth in vivo. LINC00320 was under-expressed and AQP9 was over-expressed in glioma tissues. Further mechanistic investigation showed that LINC00320 downregulated AQP9 by inhibiting the recruitment of NFKB1 to the promoter region of AQP9. LINC00320 overexpression or AQP9 silencing inhibited the proliferation of glioma cells and angiogenesis of MVECs. Also, upregulation of LINC00320 restrained tumor growth and angiogenesis in xenograft mice by downregulating AQP9. Taken together, LINC00320 acts as a tumor suppressor in glioma, thus presenting a novel therapeutic target.

Integrated analysis identifies AQP9 correlates with immune infiltration and acts as a prognosticator in multiple cancers

Aquaporin 9 (AQP9), as an aquaglyceroporin, is expressed in many immune cells and plays important role in tumor initiation and progression. However, the relationship between AQP9 and tumor-infiltrating cells, and its prognostic value in cancers still require comprehensive understanding. Herein, we aimed to elucidate the correlations of AQP9 with prognosis and immune infiltration levels in diverse cancers. We detected the expression and survival data of AQP9 through Oncomine, TIMER, Kaplan–Meier Plotter and PrognoScan databases. The correlations between AQP9 and immune infiltrates were analyzed in TIMER database. Our results found that high AQP9 expression was significantly correlated with worse prognosis in breast, colon and lung cancers, while predicted better prognosis in gastric cancer. Moreover, AQP9 had significant association with various immune infiltrating cells including CD8⁺ and CD4⁺ T cells, neutrophils, macrophages and dendritic cells (DCs), and diverse immune gene markers in BRCA, COAD, LUAD, LUSC and STAD. AQP9 was also significantly correlated with the regulation of tumor associated macrophages (TAM). These results indicate that AQP9 can play as a significant biomarker to determine the prognosis and the immune infiltrating levels in different cancers. It might also contribute to the development of the immunotherapy in breast, colon, lung and gastric cancers.

Combined Systematic Review and Transcriptomic Analyses of Mammalian Aquaporin Classes 1 to 10 as Biomarkers and Prognostic Indicators in Diverse Cancers

Aquaporin (AQP) channels enable regulated transport of water and solutes essential for fluid homeostasis, but they are gaining attention as targets for anticancer therapies. Patterns of AQP expression and survival rates for patients were evaluated by systematic review (PubMed and Embase) and transcriptomic analyses of RNAseq data (Human Protein Atlas database). Meta-analyses confirmed predominantly negative associations between AQP protein and RNA expression levels and patient survival times, most notably for AQP1 in lung, breast and prostate cancers; AQP3 in esophageal, liver and breast cancers; and AQP9 in liver cancer. Patterns of AQP expression were clustered for groups of cancers and associated with risk of death. A quantitative transcriptomic analysis of AQP1-10 in human cancer biopsies similarly showed that increased transcript levels of AQPs 1, 3, 5 and 9 were most frequently associated with poor survival. Unexpectedly, increased AQP7 and AQP8 levels were associated with better survival times in glioma, ovarian and endometrial cancers, and increased AQP11 with better survival in colorectal and breast cancers. Although molecular mechanisms of aquaporins in pathology or protection remain to be fully defined, results here support the hypothesis that overexpression of selected classes of AQPs differentially augments cancer progression. Beyond fluid homeostasis, potential roles for AQPs in cancers (suggested from an expanding appreciation of their functions in normal tissues) include cell motility, membrane process extension, transport of signaling molecules, control of proliferation and apoptosis, increased mechanical compliance, and gas exchange. AQP expression also has been linked to differences in sensitivity to chemotherapy treatments, suggesting possible roles as biomarkers for personalized treatments. Development of AQP pharmacological modulators, administered in cancer-specific combinations, might inspire new interventions for controlling malignant carcinomas.

Aquaporin-9, Mediated by IGF2, Suppresses Liver Cancer Stem Cell Properties via Augmenting ROS/β-Catenin/FOXO3a Signaling

Liver cancer stem cells (LCSCs) play a critical role in hepatocellular carcinoma (HCC) by virtue of their aggressive behavior and association with poor prognoses. Aquaporin-9 (AQP9) is a transmembrane protein that transports water and reportedly transports H₂O₂. Recent studies have shown that AQP9 expression has a negative effect on HCC cell invasion by inhibiting the epithelial-to-mesenchymal transition. However, the role of AQP9 in LCSCs remains obscure. We performed spheroid formation assay and flow cytometric analysis to investigate LCSCs stemness. CD133⁺ and CD133^- cells were isolated by flow cytometry. Real-time quantitative PCR (qRT-PCR), Western blot analysis, and immunofluorescence assay were used to estimate gene expression. The protein association of β-catenin with TCF4 and the interaction of β-catenin with FOXO3a were detected by immunoprecipitation (IP). Here, we found that AQP9 was preferentially decreased in LCSCs. Upregulated AQP9 significantly suppressed LCSCs stemness. In contrast, the inhibition of AQP9 had the opposite effect. Mechanistically, AQP9 was shown to be downregulated by insulin-like growth factor 2 (IGF2), which was widely reported to contribute to maintaining CSCs stemness. Furthermore, AQP9 overexpression was found to result in reactive oxygen species (ROS) accumulation, which inhibited β-catenin activity by attenuating the interaction of β-catenin with TCF4 while concurrently enhancing the association of β-catenin with FOXO3a, ultimately inhibiting LCSCs stemness. Our study implies that stimulation of the AQP9 signaling axis may be a novel preventive and/or therapeutic approach for eliminating LCSCs. IMPLICATIONS: Our findings demonstrate that AQP9 signaling axis may be a novel preventive and/or therapeutic approach for eliminating LCSCs.

Aquaporin 9 inhibits growth and metastasis of hepatocellular carcinoma cells via Wnt/β-catenin pathway

Hepatocellular carcinoma (HCC) is the most common type of liver cancer worldwide, and it is the second leading cause of cancer-related mortality. Aquaporin 9 (AQP9) is an essential aquaporin in the liver and located in the basolateral membrane of hepatocytes, but its roles on HCC has not been completely elucidated. This study investigated the regulatory functions of AQP9 in the pathogenesis of HCC. The expression levels of AQP9 were significantly down-regulated in HCC tissues and cells, which was also correlated with tumor size and number, TNM stage, five-year survival rate, lymphatic and distal metastasis within the patients. Furthermore, overexpressed AQP9 suppressed the proliferation, migration and invasion of HCC cells. The levels of PCNA, E-cad, N-cad, α-SMA, DVL2, GSK-3β, cyclinD1 and β-catenin in HCC cells were reduced by overexpressed AQP9, while cell apoptosis was remarkably enhanced. Additionally, following the treatment with Wnt/β-catenin signaling inhibitor (XAV939), the proliferative activity of HCC cells was significantly inhibited; PCNA and EMT-related markers were down-regulated; migration and invasion of cells were notably suppressed; cell apoptotic rate was decreased. Vice versa, after the cells were treated with Wnt/β-catenin inducer (SKL2001), the effects caused by overexpressed AQP9 were abrogated. In vivo studies indicated that tumor volume and weight were remarkably decreased in AQP9 overexpression group, where the levels of Wnt/β-catenin signaling- and EMT-associated molecules were also reduced. Taken together, our results suggested that overexpressed AQP9 could inhibit growth and metastasis of HCC cells via Wnt/β-catenin pathway. AQP9 may be a promising therapeutic target for the treatment of patients with HCC.

LncRNA MALAT1 promotes neuropathic pain progression through the miR‑154‑5p/AQP9 axis in CCI rat models

The present study investigated the role and molecular mechanism of long non‑coding RNA (lncRNA) metastasis associated lung adenocarcinoma transcript (MALAT)1 in neuropathic pain in rat chronic constriction injury (CCI) model. Reverse transcription‑quantitative PCR and western blot analysis were used to detect the expression levels of MALAT1, microRNA (miR)‑154‑5p and aquaporin (AQP)9 in spinal cord tissue and microglia of CCI rats. ELISA and pain behavioral assays were used to observe the effect of MALAT1 on neuropathic pain and neuroinflammation in model rats, and to verify its molecular mechanism through bioinformatics and luciferase experiments. The results of the present study identified that the expression levels of MALAT1 and AQP9 were upregulated, while miR‑154‑5p was downregulated in spinal cord tissue and microglia of CCI rats. MALAT1 knockdown in CCI model rats significantly induced the occurrence of neuropathic pain, while the upregulation of miR‑154‑5p could reverse this process. The present study also identified that miR‑154‑5p was the target gene of MALAT1, and AQP9 was the target gene of miR‑154‑5p. AQP9 knockdown promoted the occurrence of neuropathic pain. In conclusion, lncRNA MALAT1 promotes the progression of neuropathic pain in rats by reducing miR‑154‑5p and increasing AQP9. The MALAT1/miR‑154‑5p/AQP9 axis can be used as a new therapeutic target for neuropathic pain.

Prognostic implications of Aquaporin 9 expression in clear cell renal cell carcinoma

Background

Growing evidence has demonstrated immune reactivity as a confirmed important carcinogenesis and therapy efficacy for clear cell renal cell carcinoma (ccRCC). Aquaporin 9 (AQP9) is involved in many immune-related signals; however, its role in ccRCC remains to be elucidated. This study investigated AQP9 expression in tumor tissues and defined the prognostic value in ccRCC patients.

Methods

A total of 913 ccRCC patients with available RNA-sequence data from the Cancer Genome Atlas (TCGA) database and Fudan University Shanghai Cancer Center (FUSCC) were consecutively recruited in analyses. Differential transcriptional and proteome expression profiles were obtained and validated using multiple datasets. A partial likelihood test from Cox regression analysis was developed to address the influence of independent factors on progression-free survival (PFS) and overall survival (OS). The Kaplan–Meier method and log-rank test were performed to assess survival. Receiver operating characteristic (ROC) curves were used to describe binary classifier value of AQP9 using area under the curve (AUC) score. Functional enrichment analyses and immune infiltration analysis were used to describe significantly involved hallmark pathways of hub genes.

Results

Significantly elevated transcriptional and proteomic AQP9 expressions were found in ccRCC samples. Increased AQP9 mRNA expression was significantly associated with advanced clinicopathological parameters and correlated with shorter PFS and OS in TCGA and FUSCC cohorts (p < 0.001). ROC curves suggested the significant diagnostic and prognostic ability of AQP9 (PFS, AUC = 0.823; OS, AUC = 0.828). Functional annotations indicated that AQP9 is involved in the most significant hallmarks including complement, coagulation, IL6/JAK–STAT3, inflammatory response and TNF-alpha signaling pathways.

Conclusion

Our study revealed that elevated AQP9 expression was significantly correlated with aggressive progression, poor survival and immune infiltrations in ccRCC patients, and we validated its prognostic value in a real-world cohort. These data suggest that AQP9 may act as an oncogene and a promising prognostic marker in ccRCC.

Pathways of arsenic uptake and efflux

Arsenic is a non-essential, environmentally ubiquitous toxic metalloid. In response to this pervasive environmental challenge, organisms evolved mechanisms to confer resistance to arsenicals. Inorganic pentavalent arsenate is taken into most cells adventitiously by phosphate uptake systems. Similarly, inorganic trivalent arsenite is taken into most cells adventitiously, primarily via aquaglyceroporins or sugar permeases. The most common strategy for tolerance to both inorganic and organic arsenicals is by efflux that extrude them from the cytosol. These efflux transporters span across kingdoms and belong to various families such as aquaglyceroporins, major facilitator superfamily (MFS) transporters, ATP-binding cassette (ABC) transporters and potentially novel, yet to be discovered families. This review will outline the properties and substrates of known arsenic transport systems, the current knowledge gaps in the field, and aims to provide insight into the importance of arsenic transport in the context of the global arsenic biogeocycle and human health.

Role of pre-miR-532 (miR-532-5p and miR-532-3p) in regulation of gene expression and molecular pathogenesis in renal cell carcinoma

Analyses of our previously determined microRNA (miRNA) expression signature of renal cell carcinoma (RCC) and The Cancer Genome Atlas (TCGA) database revealed that both strands of the pre-miR-532-duplex-miR-532-5p (the guide strand) and miR-532-3p (the passenger strand)- are closely associated with poor prognosis of RCC patients (P = 0.0411 and P = 0.022, respectively). In this study we investigated the functional significance of these miRNAs and identified gene targets involved in RCC pathogenesis. Ectopic expression of these miRNAs significantly attenuated the malignant phenotypes including proliferation, migration and invasion of two RCC cell lines, 786-O and A498. A combination of genome-wide gene expression and in silico database analyses revealed 36 and 34 genes as putative target oncogenes regulated by miR-532-5p and miR-532-3p, respectively, in RCC cells. Among these targets, expression of aquaporin9 (AQP9), a water channel protein, was directly regulated by both miR-532-5p and miR-532-3p, and high expression levels of AQP9 were significantly associated with poor prognosis of RCC patients (P = 2.03e-05). Multivariate analysis indicated that AQP9 expression is an independent prognostic factor for RCC patients. Aberrant AQP9 expression at both the gene and protein level was detected in RCC clinical specimens. siRNA-mediated knockdown of AQP9 by si-AQP9 inhibited the malignant phenotypes of RCC cells. Rescue assays of AQP9 overexpression showed that the miR-532/AQP9 axis was closely involved in RCC oncogenesis. The identification of antitumor miRNAs and their targets will contribute to an increased understanding of the molecular pathogenesis of RCC.

Aquaglyceroporins: Drug Targets for Metabolic Diseases?

Aquaporins (AQPs) are a family of transmembrane channel proteins facilitating the transport of water, small solutes, and gasses across biological membranes. AQPs are expressed in all tissues and ensure multiple roles under normal and pathophysiological conditions. Aquaglyceroporins are a subfamily of AQPs permeable to glycerol in addition to water and participate thereby to energy metabolism. This review focalizes on the present knowledge of the expression, regulation and physiological roles of AQPs in adipose tissue, liver and endocrine pancreas, that are involved in energy metabolism. In addition, the review aims at summarizing the involvement of AQPs in metabolic disorders, such as obesity, diabetes and liver diseases. Finally, challenges and recent advances related to pharmacological modulation of AQPs expression and function to control and treat metabolic diseases are discussed.

Significance of aquaporins' expression in the prognosis of gastric cancer

Gastric carcinoma is one of the most lethal malignancy at present with leading cause of cancer-related deaths worldwide. Aquaporins (AQPs) are a family of small, integral membrane proteins, which have been evidenced to play a crucial role in cell migration and proliferation of different cancer cells including gastric cancers. However, the aberrant expression of specific AQPs and its correlation to detect predictive and prognostic significance in gastric cancer remains elusive. In the present study, we comprehensively explored immunohistochemistry based map of protein expression profiles in normal tissues, cancer and cell lines from publicly available Human Protein Atlas (HPA) database. Moreover, to improve our understanding of general gastric biology and guide to find novel predictive prognostic gastric cancer biomarker, we also retrieved 'The Kaplan-Meier plotter' (KM plotter) online database with specific AQPs mRNA to overall survival (OS) in different clinicopathological features. We revealed that ubiquitous expression of AQPs protein can be effective tools to generate gastric cancer biomarker. Furthermore, high level AQP3, AQP9, and AQP11 mRNA expression were correlated with better OS in all gastric patients, whereas AQP0, AQP1, AQP4, AQP5, AQP6, AQP8, and AQP10 mRNA expression were associated with poor OS. With regard to the clinicopathological features including Laurens classification, clinical stage, human epidermal growth factor receptor 2 (HER2) status, and different treatment strategy, we could illustrate significant role of individual AQP mRNA expression in the prognosis of gastric cancer patients. Thus, our results indicated that AQP's protein and mRNA expression in gastric cancer patients provide effective role to predict prognosis and act as an essential agent to therapeutic strategy.

Ectopic expression of aquaporin-5 in noncancerous epithelial MDCK cells changes cellular morphology and actin fiber formation without inducing epithelial-to-mesenchymal transition

Aquaporin-5 (AQP5) is a plasma membrane water channel mainly expressed in secretory glands. Increased expression of AQP5 is observed in multiple cancers, including breast cancer, where high expression correlates with the degree of metastasis and poor prognosis. Moreover, studies in cancer cells have suggested that AQP5 activates Ras signaling, drives morphological changes, and in particular increased invasiveness. To design intervention strategies, it is of utmost importance to characterize and dissect the cell biological changes induced by altered AQP5 expression. To isolate the effect of AQP5 overexpression from the cancer background, AQP5 was overexpressed in normal epithelial MDCK cells which have no endogenous AQP5 expression. AQP5 overexpression promoted actin stress fiber formation and lamellipodia dynamics. Moreover, AQP5 decreased cell circularity. Phosphorylation of AQP5 on serine 156 in the second intracellular loop has been shown to activate the Ras pathway. When serine 156 was mutated to alanine to mimic the nonphosphorylated state, the decrease in cell circularity was reversed, indicating that the AQP5-Ras axis is involved in the effect on cell shape. Interestingly, the cellular changes mediated by AQP5 were not associated with induction of epithelial-to-mesenchymal transition. Thus, AQP5 may contribute to cancer by altering cellular morphology and actin organization, which increase the metastatic potential.

Prognostic values of aquaporins mRNA expression in human ovarian cancer

Aquaporins (AQPs), a family of transmembrane channel, are composed of 13 identified members (AQP0–12). Accumulating evidences reported that AQPs were correlated with various biological roles and represented a prognostic predictor in various cancer types. However, the prognostic value of AQPs expression in ovarian cancer remains unclear. Using ‘Kaplan–Meier plotter’ (KM plotter) online database, we explored the predictive prognostic value of individual AQPs members’ mRNA expression to overall survival (OS) in different clinical data, such as histology, pathological grades, clinical stages, TP53 status, and applied chemotherapy in ovarian cancer patients. Our results revealed that higher AQP0, AQP1, and AQP4 mRNA expression were correlated with poor OS, whereas higher AQP3, AQP5, AQP6, AQP8, AQP10, and AQP11 showed better OS in ovarian cancer patients. Moreover, AQP4 and AQP8 showed poor OS in TP53-mutated ovarian cancer patients and AQP1 presented unfavorable OS in both TP53 mutated and wild ovarian cancer patients. Additionally, AQP3, AQP6, and AQP11 mRNA expression were correlated with better OS, whereas AQP0 and AQP1 showed poor OS in all ovarian cancer patients treated with Platin, Taxol, and Taxol + Platin chemotherapy. AQP5, AQP8, and AQP10 were associated with improved OS, however, AQP4 predicted unfavorable OS in all patients treated with Platin chemotherapy. Our results suggest that individual AQPs, except AQP2 and AQP9, are associated with unique prognostic significance and may thus act as new predictive prognostic indicators and potential drug therapeutic target in ovarian cancer.

Immunohistochemical evalulation of activated Ras and Rac1 as potential downstream effectors of aquaporin-5 in breast cancer in vivo

Aberrant levels of aquaporin-5 (AQP5) expression have been observed in several types of cancer, including breast cancer, where AQP5 overexpression is associated with metastasis and poor prognosis. In cultured cancer cells, AQP5 facilitates cell migration and activates Ras signaling. Both increased cell migration and Ras activation are associated with cancer metastasis, but so far it is unknown if AQP5 also affects these processes in vivo. Therefore, we investigated if high AQP5 expression in breast cancer tissue correlated with increased activation of Ras and of Rac1, which is a GTPase also involved in cell migration. This was accomplished by immunohistochemical analysis of invasive ductal carcinoma of breast tissue sections from human patients, followed by qualitative and quantitative correlation analysis between AQP5 and activated Ras and Rac1. Immunohistochemistry revealed that activation of Ras and Rac1 was positively correlated. There was, however, no correlation between high AQP5 expression and activation of Ras, whereas a nonsignificant, but positive, tendency between the levels of AQP5 and activated Rac1 levels was observed. In summary, this is the first report that correlates AQP5 expression levels to downstream signaling partners in breast cancer tissue sections. The results suggest Rac1 as a potential downstream signaling partner of AQP5 in vivo.