Depletion of CPNE7 sensitizes colorectal cancer to 5-fluorouracil by downregulating ATG9B expression.

We aimed to explore the biological function of CPNE7 and determine the impact of CPNE7 on chemotherapy resistance in colorectal cancer (CRC) patients. According to the Gene Expression Profiling Interactive Analysis database and previously published data, CPNE7 was identified as a potential oncogene in CRC. RT-qPCR and Western blotting were performed to verify the expression of CPNE7. Chi-square test was used to evaluate the associations between CPNE7 and clinical features. Cell proliferation, colony formation, cell migration and invasion, cell cycle and apoptosis were assessed to determine the effects of CPNE7. Transcriptome sequencing was used to identify potential downstream regulatory genes, and gene set enrichment analysis was performed to investigate downstream pathways. The effect of CPNE7 on 5-fluorouracil chemosensitivity was verified by half maximal inhibitory concentration (IC50). Subcutaneous tumorigenesis assay was used to examine the role of CPNE7 in sensitivity of CRC to chemotherapy in vivo. Transmission electron microscopy was used to detect autophagosomes. CPNE7 was highly expressed in CRC tissues, and its expression was correlated with T stage and tumour site. Knockdown of CPNE7 inhibited the proliferation and colony formation of CRC cells and promoted apoptosis. Knockdown of CPNE7 suppressed the expression of ATG9B and enhanced the sensitivity of CRC cells to 5-fluorouracil in vitro and in vivo. Knockdown of CPNE7 reversed the induction of the autophagy pathway by rapamycin and reduced the number of autophagosomes. Depletion of CPNE7 attenuated the malignant proliferation of CRC cells and enhanced the chemosensitivity of CRC cells to 5-fluorouracil.

Combination of size-exclusion chromatography and ion exchange adsorption for improving the proteomic analysis of plasma-derived extracellular vesicles.

Extracellular vesicles (EVs) are lipid membrane vesicles released by live cells that carry a variety of biomolecules, including nucleic acids, lipids, and proteins. Recently, proteins in plasma-derived EVs have emerged as novel biomarkers with essential functions in the diagnosis and prognosis of human diseases. However, the current methods of isolating EVs from plasma often lead to coisolated impurities in biological fluids. Therefore, before performing any research protocol, the process of extracting EVs from plasma for proteomic analysis must be optimized. In this study, two EV isolation strategies, size exclusion chromatography (SEC) and SEC combined with ion exchange adsorption (SEC + IEA), were compared in terms of the purity and quantity of protein in EVs. Our results demonstrated that, compared to single-step SEC, SEC combined with IEA could produce plasma-derived EVs with a higher purity by decreasing the abundance of lipoprotein. Additionally, with MS analysis, we demonstrated that the combination approach maintained the stability and improved the purity of EVs in many plasma samples. Furthermore, by combining SEC with IEA, more cancer-associated proteins were detected in the plasma of various cancer samples.

RNA sequencing reveals the implication of the circRNA-associated ceRNA network in oesophageal squamous cell carcinoma.

Circular RNAs (circRNAs) have attracted increasing attention in cancer research. However, there are few studies about the high-throughput sequencing for clinical cohorts focussing on the expression characteristics and regulatory networks of circRNAs in oesophageal squamous cell carcinoma (ESCC) until now. Present study aim to comprehensively recognize the functional and mechanistic patterns of circRNA through constructing a circRNA-related competing endogenous RNA (ceRNA) network in ESCC. Summarily, RNA high-throughput sequencing was adopted to assess the circRNA, miRNA and mRNA expression profiles in ESCC. Through bioinformatics methods, a circRNA-miRNA-mRNA coexpression network was constructed and hub genes was identified. Finally, cellular function experiments combined with bioinformatics analysis were conducted to verify the identified circRNA was involved in the progression of ESCC through ceRNA mechanism. In this study, we established a ceRNA regulatory network, including 5 circRNAs, 7 miRNAs and 197 target mRNAs, and 20 hub genes were screened and identified to exert important roles in the progression of ESCC. As a verification, hsa_circ_0002470 (circIFI6) was revealed to be highly expressed in ESCC and regulate the expression of hub genes by absorbing miR-497-5p and miR-195-5p through ceRNA mechanism. Our results further indicated that silencing of circIFI6 repressed proliferation and migration of ESCC cells, highlighting the tumour promotion effects of circIFI6 in ESCC. Collectively, our study contributes a new insight into the progression of ESCC from the perspective of the circRNA-miRNA-mRNA network, shedding light on the circRNA research in ESCC.

Identification of the immunogenic membrane proteins, catalase, PgbA, and PgbB, as potential antigens against Helicobacter pylori.

AIMS: This study aims to investigate the specific membrane antigens that are targeted by antibodies raised against Helicobacter pylori. METHODS AND RESULTS: Bovine milk antibodies were prepared using whole H. pylori, purified membrane proteins, or both. Enzyme-linked immunosorbent assay and sodium dodecyl sulfate-polyacrylamide gel electrophoresis experiments revealed that these immunogens triggered anti-H. pylori antibody production in milk. The highest antibody titer was induced by the mixture of whole bacteria and purified membrane proteins. The antibodies induced by mixed immunogens significantly inhibited H. pylori growth in vitro and were used to identify catalase, plasminogen-binding protein A (PgbA), and PgbB via western blotting, immunoprecipitation, and two-dimensional western blotting followed by liquid chromatography with tandem mass spectrophotometry. The immunogenicity of PgbA and PgbB was verified in mice vaccinated with their B-cell epitope vaccines. Following prophylactic vaccination of C57BL/6 mice, each of the three antigens alone and their combination reduced the weight loss in mice, increased antibody titers, and relieved the inflammatory status of the gastric mucosa following H. pylori infection. CONCLUSIONS: Catalase, PgbA, and PgbB could serve as valuable membrane antigens for the development of anti-H. pylori immunotherapies.

Uncovering potential genes in colorectal cancer based on integrated and DNA methylation analysis in the gene expression omnibus database.

BACKGROUND: Colorectal cancer (CRC) is major cancer-related death. The aim of this study was to identify differentially expressed and differentially methylated genes, contributing to explore the molecular mechanism of CRC. METHODS: Firstly, the data of gene transcriptome and genome-wide DNA methylation expression were downloaded from the Gene Expression Omnibus database. Secondly, functional analysis of differentially expressed and differentially methylated genes was performed, followed by protein-protein interaction (PPI) analysis. Thirdly, the Cancer Genome Atlas (TCGA) dataset and in vitro experiment was used to validate the expression of selected differentially expressed and differentially methylated genes. Finally, diagnosis and prognosis analysis of selected differentially expressed and differentially methylated genes was performed. RESULTS: Up to 1958 differentially expressed (1025 up-regulated and 993 down-regulated) genes and 858 differentially methylated (800 hypermethylated and 58 hypomethylated) genes were identified. Interestingly, some genes, such as GFRA2 and MDFI, were differentially expressed-methylated genes. Purine metabolism (involved IMPDH1), cell adhesion molecules and PI3K-Akt signaling pathway were significantly enriched signaling pathways. GFRA2, FOXQ1, CDH3, CLDN1, SCGN, BEST4, CXCL12, CA7, SHMT2, TRIP13, MDFI and IMPDH1 had a diagnostic value for CRC. In addition, BEST4, SHMT2 and TRIP13 were significantly associated with patients' survival. CONCLUSIONS: The identified altered genes may be involved in tumorigenesis of CRC. In addition, BEST4, SHMT2 and TRIP13 may be considered as diagnosis and prognostic biomarkers for CRC patients.

Perspectives from recent advances of Helicobacter pylori vaccines research.

BACKGROUND: Helicobacter pylori (H. pylori) infection is the main factor leading to some gastric diseases. Currently, H. pylori infection is primarily treated with antibiotics. However, with the widespread application of antibiotics, H. pylori resistance to antibiotics has also gradually increased year by year. Vaccines may be an alternative solution to clear H. pylori. AIMS: By reviewing the recent progress on H. pylori vaccines, we expected it to lead to more research efforts to accelerate breakthroughs in this field. MATERIALS & METHODS: We searched the research on H. pylori vaccine in recent years through PubMed®, and then classified and summarized these studies. RESULTS: The study of the pathogenic mechanism of H. pylori has led to the development of vaccines using some antigens, such as urease, catalase, and heat shock protein (Hsp). Based on these antigens, whole-cell, subunit, nucleic acid, vector, and H. pylori exosome vaccines have been tested. DISCUSSION: At present, researchers have developed many types of vaccines, such as whole cell vaccines, subunit vaccines, vector vaccines, etc. However, although some of these vaccines induced protective immunity in mouse models, only a few were able to move into human trials. We propose that mRNA vaccine may play an important role in preventing or treating H. pylori infection. The current study shows that we have developed various types of vaccines based on the virulence factors of H. pylori. However, only a few vaccines have entered human clinical trials. In order to improve the efficacy of vaccines, it is necessary to enhance T-cell immunity. CONCLUSION: We should fully understand the pathogenic mechanism of H. pylori and find its core antigen as a vaccine target.

Tandem mass tagging combined with liquid chromatography-tandem mass spectrometry technique to detect protein markers in gastroesophageal junction adenocarcinoma.

BACKGROUND: Gastroesophageal junction adenocarcinoma (GEJA) is a malignant tumor located at the junction of the esophagus and stomach, the incidence of which is increasing year by year, while screening for early biomarkers is limited. Tandem mass tagging (TMT) coupled with liquid chromatography-tandem mass spectrometry (LC/MS/MS) has been used to screen for differential proteins in various cancers. METHODS: Differential proteins in GEJA and precancerous lesions were screened using TMT-LC/MS/MS, and then proteins that met expectations were selected for trend clustering analysis, combined with GO and KEGG analysis for functional annotation of differential proteins in GEJA. Then, parallel reaction monitoring and immunohistochemistry techniques were used to validate the accuracy of the proteomics data. RESULTS: Our group screened the differential proteins during GEJA progression using proteomics technology, analyzed the expression trends and functional regions involved in the differential proteins during carcinogenesis, and validated the accuracy of the experimental results. CONCLUSIONS: The screening of differential proteins in GEJA carcinogenesis based on TMT-LC/MS/MS technology provides detailed information for the elucidation of GEJA progression process, pathogenesis, early screening and screening of candidate markers.

SNORA42 promotes oesophageal squamous cell carcinoma development through triggering the DHX9/p65 axis.

Small nucleolar RNAs (snoRNAs) are an important group of non-coding RNAs that have been reported to play a key role in the occurrence and development of various cancers. Here we demonstrate that Small nucleolar RNA 42 (SNORA42) enhanced the proliferation and migration of Oesophageal squamous carcinoma cells (ESCC) via the DHX9/p65 axis. Our results found that SNORA42 was significantly upregulated in ESCC cell lines, tissues and serum of ESCC patients. The high expression level of SNORA42 was positively correlated with malignant characteristics and over survival probability of patients with ESCC. Through in vitro and in vivo approaches, we demonstrated that knockdown of SNORA42 significantly impeded ESCC growth and metastasis whereas overexpression of SNORA42 got opposite effects. Mechanically, SNORA42 promoted DHX9 expression by attenuating DHX9 transports into the cytoplasm, to protect DHX9 from being ubiquitinated and degraded. From the KEGG analysis of Next-Generation Sequencing, the NF-κB pathway was one of the most regulated pathways by SNORA42. SNORA42 enhanced phosphorylation of p65 and this effect could be reversed by NF-κB inhibitor, BAY11-7082. Moreover, SNORA42 activated NF-κB signaling through promoting the transcriptional co-activator DHX9 interacted with p-p65, inducing NF-κB downstream gene expression. In summary, our study highlights the potential of SNORA42 is up-regulated in ESCC and promotes ESCC development partly via interacting with DHX9 and triggering the DHX9/p65 axis.

SNHG5 inhibits the progression of EMT through the ubiquitin-degradation of MTA2 in oesophageal cancer.

A substantial fraction of transcripts are known as long noncoding RNAs (lncRNAs), and these transcripts play pivotal roles in the development of cancer. However, little information has been published regarding the functions of lncRNAs in oesophageal squamous cell carcinoma (ESCC) and the underlying mechanisms. In our previous studies, we demonstrated that small nucleolar RNA host gene 5 (SNHG5), a known lncRNA, is dysregulated in gastric cancer (GC). In this study, we explored the expression and function of SNHG5 in development of ESCC. SNHG5 was found to be downregulated in human ESCC tissues and cell lines, and this downregulation was associated with cancer progression, clinical outcomes and survival rates of ESCC patients. Furthermore, we also found that overexpression of SNHG5 significantly inhibited the proliferation, migration and invasion of ESCC cells in vivo and in vitro. Notably, we found that metastasis-associated protein 2 (MTA2) was pulled down by SNHG5 in ESCC cells using RNA pulldown assay. We also found that SNHG5 reversed the epithelial-mesenchymal transition by interacting with MTA2. In addition, overexpression of SNHG5 downregulated the transcription of MTA2 and caused its ubiquitin-mediated degradation. Thus, overexpression of MTA2 partially abrogated the effect of SNHG5 in ESCC cell lines. Furthermore, we found that MTA2 mRNA expression was significantly elevated in ESCC specimens, and a negative correlation between SNHG5 and MTA2 expression was detected. Overall, this study demonstrated, for the first time, that SNHG5-regulated MTA2 functions as an important player in the progression of ESCC and provide a new potential therapeutic strategy for ESCC.

DUOX2 promotes the progression of colorectal cancer cells by regulating the AKT pathway and interacting with RPL3.

Dual oxidase 2 (DUOX2) is an important regulatory protein in the organic process of thyroid hormone iodine. Mounting evidence suggests that DUOX2 plays a crucial role in the occurrence and development of cancers. However, the function and mechanism of DUOX2 in colorectal cancer (CRC) have not been fully clarified. In the present study, the relationship between the expression of DUOX2 and the clinicopathological features and prognosis of CRC patients was analyzed. Furthermore, the effects of DUOX2 on proliferation and invasion in vitro and in vivo were examined. DUOX2-associated proteins were identified by immunoprecipitation (IP). Next-generation sequencing detection was performed to illustrate the mechanism of DUOX2 in CRC cells. It was found that the expression levels of DUOX2 in metastatic sites were significantly higher than those in primary tumor tissues, and this was demonstrated to be associated with poor prognosis. The knockdown of DUOX2 inhibited the invasion and migration of CRC cells. Furthermore, DUOX2 regulated the stability of ribosomal protein uL3 (RPL3) by affecting the ubiquitination status of RPL3, and the invasion and migration ability of DUOX2 can be reversed by the overexpression of RPL3. The downregulation of DUOX2 can affect the expression level of a large number of genes, and a number of these are enriched in the PI3K-AKT pathway. Some of the changes caused by DUOX2 can be reversed by RPL3. In summary, DUOX2 exhibits a significantly higher expression in CRC tumor samples, and facilitates the invasion and metastasis ability of CRC cells by interacting with RPL3.

MTA2 promotes the metastasis of esophageal squamous cell carcinoma via EIF4E-Twist feedback loop.

Metastasis-associated protein 2 (MTA2) is frequently amplified in many types of cancers; however, the role and underlying molecular mechanism of MTA2 in esophageal squamous cell carcinoma (ESCC) remain unknown. Here, we reported that MTA2 is highly expressed in ESCC tissue and cells, and is closely related to the malignant characteristics and poor prognosis of patients with ESCC. Through in vitro and in vivo experiments, we demonstrated that MTA2 significantly promoted ESCC growth, metastasis, and epithelial-mesenchymal transition (EMT) progression. This integrative analysis combined with expression microarray showed that MTA2 could interact with eukaryotic initiation factor 4E (EIF4E), which positively regulates the expression of Twist, known as a master regulator of EMT. Moreover, the results of chromatin immunoprecipitation revealed that MTA2 was recruited to the E-cadherin promoter by Twist, which reduced the acetylation level of the promoter region and thus inhibited expression of E-cadherin, and subsequently promoted the aggressive progression of ESCC. Collectively, our study provided novel evidence that MTA2 plays an aggressive role in ESCC metastasis by a novel EIF4E-Twist positive feedback loop, which may provide a potential therapeutic target for the management of ESCC.

Extracellular vesicles isolated by size-exclusion chromatography present suitability for RNomics analysis in plasma.

BACKGROUND: Extracellular vesicles (EVs), known as cell-derived membranous structures harboring a variety of biomolecules, have been widely used in liquid biopsy. Due to the complex biological composition of plasma, plasma RNA omics analysis (RNomics) is easily affected, thus it is necessary to select an optimal strategy from exiting methods according to the performance for intended application. METHODS: In this study, four different strategies for EVs isolation were performed and compared (i.e. ultracentrifugation (UC), size exclusion chromatography (SEC), and two most frequently-used commercially available isolation kit (ExoQuick and exoEasy). We compared the yield, purity, PCR quantification of RNAs, miRNA-seq analyses and mRNA-seq analyses of RNAs from EVs isolated using four methods. RESULTS: The results showed that the lowest miRNA binding protein AGO2 (Argonaute-2) and the highest EVs-specific miRNA and lncRNA were observed in EVs obtained through SEC, meanwhile the content of the non-specific miRNA was the lowest. Further RNA-Seq data revealed that RNAs obtained via SEC presented more useful reads for both miRNA and mRNA. Furthermore, the mRNA delivered via SEC tended to have a concentration comparable to the ideal FPKM (Fragments Per Kilobase Million) value. CONCLUSIONS: SEC shall be used as an optimal strategy for the isolation of EVs in plasma RNomics analysis.

Angiogenesis-related lncRNAs predict the prognosis signature of stomach adenocarcinoma.

BACKGROUND: Stomach adenocarcinoma (STAD), which accounts for approximately 95% of gastric cancer types, is a malignancy cancer with high morbidity and mortality. Tumor angiogenesis plays important roles in the progression and pathogenesis of STAD, in which long noncoding RNAs (lncRNAs) have been verified to be crucial for angiogenesis. Our study sought to construct a prognostic signature of angiogenesis-related lncRNAs (ARLncs) to accurately predict the survival time of STAD. METHODS: The RNA-sequencing dataset and corresponding clinical data of STAD were acquired from The Cancer Genome Atlas (TCGA). ARLnc sets were obtained from the Ensemble genome database and Molecular Signatures Database (MSigDB, Angiogenesis M14493, INTegrin pathway M160). A ARLnc-related prognostic signature was then constructed via univariate Cox and multivariate Cox regression analysis in the training cohort. Survival analysis and Cox regression were performed to assess the performance of the prognostic signature between low- and high-risk groups, which was validated in the validation cohort. Furthermore, a nomogram that combined the clinical pathological characteristics and risk score conducted to predict the overall survival (OS) of STAD. In addition, ARLnc-mRNA coexpression pairs were constructed with Pearson's correlation analysis and visualized to infer the functional annotation of the ARLncs by gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. The expression of four ARLncs in STAD and their correlation with the angiogenesis markers, CD34 and CD105, were also validated by RT-qPCR in a clinical cohort. RESULTS: A prognostic prediction signature including four ARLncs (PVT1, LINC01315, AC245041.1, and AC037198.1) was identified and constructed. The OS of patients in the high-risk group was significantly lower than that of patients in the low-risk group (p < 0.001). The values of the time-dependent area under the curve (AUC) for the ARLnc signature for 1-, 3-, and 5- year OS were 0.683, 0.739, and 0.618 in the training cohort and 0.671, 0.646, and 0.680 in the validation cohort, respectively. Univariate and multivariate Cox regression analyses indicated that the ARLnc signature was an independent prognostic factor for STAD patients (p < 0.001). Furthermore, the nomogram and calibration curve showed accurate prediction of the survival time based on the risk score. In addition, 262 mRNAs were screened for coexpression with four ARLncs, and GO analysis showed that mRNAs were mainly involved in biological processes, including angiogenesis, cell adhesion, wound healing, and extracellular matrix organization. Furthermore, correlation analysis showed that there was a positive correlation between risk score and the expression of the angiogenesis markers, CD34 and CD105, in TCGA datasets and our clinical sample cohort. CONCLUSION: Our study constructed a prognostic signature consisting of four ARLnc genes, which was closely related to the survival of STAD patients, showing high efficacy of the prognostic signature. Thus, the present study provided a novel biomarker and promising therapeutic strategy for patients with STAD.

Knockdown of ISOC1 inhibits the proliferation and migration and induces the apoptosis of colon cancer cells through the AKT/GSK-3ß pathway.

Isochorismatase domain-containing 1 (ISOC1) is a coding gene that contains an isochorismatase domain. The precise functions of ISOC1 in humans have not been clarified; however, studies have speculated that it may be involved in unknown metabolic pathways. Currently, it is reported that ISOC1 is associated with breast cancer. In this research, the aim is to investigate the critical role of ISOC1 in colorectal cancer (CRC) and to explore its biological function and mechanism in colon cancer cells. In 106 paired clinical samples, we found that the levels of ISOC1 expression were widely increased in cancer tissues compared with matched adjacent non-tumor tissues and that increased expression of ISOC1 was significantly associated with tumor size, tumor invasion, local lymph node metastasis and Tumor, Node and Metastasis (TNM) stage. Moreover, higher expression levels of ISOC1 were correlated with shorter disease-free survival in patients 2 years after surgery. In vitro, ISOC1 knockdown inhibited the proliferation and migration and induced the apoptosis of colon cancer cells, and in vivo, the xenograft tumors were also inhibited by ISOC1 silencing. We also used MTS, Transwell and cell apoptosis assays to confirm that ISOC1 plays a critical role in regulating the biological functions of colon cancer cells through the AKT/GSK-3ß pathway. Additionally, the results of confocal microscopy and western blot analysis indicated that ISOC1 knockdown could promote p-STAT1 translocation to the nucleus.

Antitumor Effect of Periplocin in TRAIL-Resistant gastric cancer cells via upregulation of death receptor through activating ERK1/2-EGR1 pathway.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), a member of the tumor necrosis factor family, induces apoptosis in a variety of cancer cells. However, gastric cancer (GC) cells are insensitive to TRAIL usually. In the previous study, we showed that Periplocin could induce apoptosis in GC cells via the activation of ERK1/2-EGR1 pathway. In the present study, we have shown that the combination of Periplocin and TRAIL had a greater inhibitory effect on gastric cancer cell viability in vitro and in vivo than Periplocin or TRAIL alone. Through upregulating the expression of DR4 and DR5 at transcriptional and protein levels, Periplocin enhanced the sensitivity of gastric cancer cells to TRAIL. Furthermore, enhanced activity of ERK1/2-EGR1 pathway was responsible for upregulating of DR4 and DR5 uponPeriplocin treatment, subsequently reducing the expression of Mcl-1 and Bcl2 and activating Bid and caspase-3/8. Collectively, these data implied that Periplocin might act as a sensitizer of TRAIL and could be a potential strategy for the treatment of GC.

Involvement of the PI3K/Akt/Nrf2 Signaling Pathway in Resveratrol-Mediated Reversal of Drug Resistance in HL-60/ADR Cells.

Resistance to chemotherapy drugs, such as adriamycin (ADR), is a common problem in acute myeloid leukemia (AML) patients. We hypothesized that the natural compound resveratrol (Res) may reverse AML drug resistance through the PI3K/Akt/Nrf2 pathway. We investigated the in vitro effect of Res using human promyelocytic leukemia cells (HL-60) and the ADR-resistant cell line (HL-60/ADR) and treated with either Res or ADR + Res. Cellular proliferation inhibition rate, auto-fluorescence intensity of ADR in HL-60/ADR cells and HL-60 cells, mRNA expression of Nrf2 and the drug-resistant gene MRP1, and protein expression of PI3K, Akt, p-Akt, Nrf2, and MRP1 were measured. Results showed ADR + Res had a more significant inhibitory effect than ADR alone on HL-60/ADR cells. Auto-fluorescence intensity of ADR in HL-60/ADR cells treated with ADR + Res significantly increased. No difference of the auto-fluorescence intensity of ADR was observed in HL-60 cells treated with ADR and ADR + Res. mRNA expression of Nrf2 and MRP1 significantly decreased in HL-60/ADR cells treated with both Res and ADR + Res; protein expression of PI3K, p-Akt, Nrf2, and MRP1 significantly decreased in HL-60/ADR cells treated with PI3K inhibitor, Res and ADR + Res. In conclusion, Res reverses the drug resistance of AML HL-60/ADR cells through regulation of the PI3K/Akt/Nrf2 signaling pathway and MRP1 expression.

C/D-Box Snord105b Promotes Tumorigenesis in Gastric Cancer via ALDOA/C-Myc Pathway.

BACKGROUND/AIMS: Small nucleolar RNAs (snoRNAs) play an important role in carcinogenesis. In this study, we identified a C/D box snoRNA, snord105b, and further investigated the function and mechanism of the snord105b in gastric cancer (GC). METHODS: The expression level of snord105b in GC tissures, sera and cell lines were detected by qRT-PCR. Cell viability was assessed using MTS assay. Transwell and wound healing assay were performed to evaluate migration and invasion, and protein expression was examined by western blotting. ChIRP and MS analysis was used to seek for the special binding protein of snord105b. RESULTS: The snord105b was upregulated and associated with tumor size, differentiation, and pathological stage in GC. Snord105b affected proliferation, migration and invasion in multiple GC cell lines. The oncoqenic activity of snord105b was also confirmed with in vivo data. Mechanistically, snord105b specifically bound to ALDOA and affected C-myc, which plays a key role in carcinogenesis and tumor development. CONCLUSION: Snord105b appears to be a novel oncogene and is clinically and functionally involved in the development of GC. Targeting snord105b and its pathway may provide new biomarkers or potential treatments for patients with GC.

p-Hydroxylcinnamaldehyde slows the progression of 4NQO-induced oesophageal tumourigenesis via the RhoA-MAPK signaling pathway.

p-Hydroxylcinnamaldehyde isolated from the Cochinchina momordica seed (CMSP) has been identified to inhibit growth and metastasis in oesophageal squamous cell carcinoma (ESCC) by inducing differentiation. The aim of the present study was to evaluate the effect and underlying mechanism of CMSP on 4-nitroquinoline 1-oxide (4NQO)-induced oesophageal tumourigenesis. In the present study, a mouse model of oesophageal preneoplastic lesions was established by providing 4NQO-containing drinking water to C57BL/6 mice. The effect of CMSP on tumourigenesis induced by the chemical mutagen and the effect of CMSP on immune function were investigated. The results showed that the incidence and pathological stage of atypical hyperplasia in oesophageal tissues were significantly reduced in CMSP-treated mice compared with untreated mice. Immunohistochemistry and pull-down assay results revealed that the expression levels of p-ERK1/2, p-SAPK/JNK, and GTP-RhoA were significantly decreased in the oesophageal tissue of CMSP-treated mice. In addition, the proportions of CD4+ T cells, CD8+ T cells, and NK cells were increased, while the proportion of CD4+ CD25+ regulatory T cells (Tregs) was decreased, in the peripheral blood of CMSP-treated mice. These results indicated that CMSP could hamper 4NQO-induced oesophageal tumourigenesis by regulating the RhoA-ERK/JNK signaling pathway and promoting immune system function, thus providing a new potential strategy for treating preneoplastic lesions of the oesophagus.

The lncRNA SNHG5/miR-32 axis regulates gastric cancer cell proliferation and migration by targeting KLF4.

Long noncoding RNAs (lncRNAs) are emerging as important regulators in cellular processes, including the development, proliferation, and migration of cancer cells. We have demonstrated in a prior study that small nucleolar RNA host gene 5 (SNHG5) is dysregulated in gastric cancer (GC). To further explore the underlying mechanisms of SNGH5 function in the development of GC, in this study, we screened the microRNAs interacting with SNHG5 and elucidated their roles in GC. We showed that SNHG5 contains a putative miR-32-binding site and that deletion of this site abolishes the responsiveness to miR-32. Suppression of SNHG5 expression by miR-32 was found to be Argonaute (Ago)2-dependent. Immunoprecipitation showed that SNHG5 could be pulled down from the Ago-2 complex with miR-32. Furthermore, it was reported that Kruppel-like factor 4 (KLF4) is a target gene of miR-32. In agreement with SNHG5 being a decoy for miR-32, we showed that KLF4 suppression by miR-32 could be partially rescued by SNHG5 overexpression, whereas miR-32 mimic rescued SNHG5 overexpression-mediated suppression of GC cell migration. In addition, we identified a negative correlation between the expression of SNHG5 and miR-32 in GC tissues. Furthermore, KLF4 expression was significantly downregulated in GC specimens, and a negative correlation between miR-32 and KLF4 expression and a positive correlation between KLF4 and SNHG5 expression levels were detected. Overall, this study demonstrated, for the first time, that the SNHG5/miR-32/KLF4 axis functions as an important player in GC cell migration and potentially contributes to the improvement of GC diagnosis and therapy.-Zhao, L., Han, T., Li, Y., Sun, J., Zhang, S., Liu, Y., Shan, B., Zheng D., Shi, J. The lncRNA SNHG5/miR-32 axis regulates gastric cancer cell proliferation and migration by targeting KLF4.

The histone deacetylase inhibitor panobinostat exerts anticancer effects on esophageal squamous cell carcinoma cells by inducing cell cycle arrest.

Esophageal squamous cell carcinoma (ESCC) is a common malignancy without effective therapy. Histone deacetylase inhibitors (HDACIs) have been demonstrated as an emerging class of anticancer drugs for a range of haematological and solid tumours. However, the effect of HDACIs has not yet been investigated on ESCC cells. In this study, HDACIs were initially considered to have anticancer activity for ESCC, due to the high expression of HDAC genes in ESCC cell lines by analysing expression data of 27 ESCC cell lines from the Broad-Novartis Cancer Cell Line Encyclopedia. Next, we used five ESCC cell lines and one normal immortalized esophageal epithelial cell line to screen three HDACIs, panobinostat (LBH589), vorinostat (SAHA), and trichostatin A (TSA), for the ability to inhibit growth. Here, we report that LBH589 more effectively suppressed cell proliferation of ESCC cell lines, in a dose-dependent manner, than TSA and SAHA, as well as had lower toxicity against the SHEE normal immortalized esophageal epithelial cell line. Further experiments indicated that LBH589 treatment significantly inhibited TP53 (mutated TP53) expression, both at the mRNA and protein level, and simultaneously increased p21 and decreased cyclin D1 expression. Taken together, we propose that LBH589 inhibits ESCC cell proliferation mainly through inducing cell cycle arrest by increasing p21 and decreasing cyclin D1 in a p53-independent manner. SIGNIFICANCE OF THE STUDY: In this study, the antitumor activity of HDACIs LBH589, SAHA, and TSA on ESCC was characterized, with LBH589 displaying the most potent anti-proliferative activity while not harming normal immortalized esophageal epithelial cells. Furthermore, we propose that LBH589 exerts its anti-proliferative effect by inducing cell cycle arrest. The ability to specifically target cancer cells indicates therapeutic potential for use of LBH589 in the treatment of ESCC.