Circ_MAPK9 promotes STAT3 and LDHA expression by silencing miR-642b-3p and affects the progression of hepatocellular carcinoma.

BACKGROUND: Aberrant expression and activation of circular RNAs (circRNAs) are closely associated with various cancers. The role of circ_MAPK9 (hsa_circ_0001566) in cancer progression remains unknown. This study aims to investigate the function, mechanism and clinical significance of circ_MAPK9 in hepatocellular carcinoma (HCC). METHODS: Circ_MAPK9 expression on the microarray of tumor from clinical HCC patients was detected by in situ hybridization (ISH). Circ_MAPK9 knockdown was achieved with siRNAs in SMMC-7721 and SK-Hep1 HCC cell lines. The biological function of circ_MAPK9 was verified in vitro by CCK8 test, colony formation assay, transwell assay, PI-Annexin V staining, and in vivo by xenograft tumor in nude mice. Fluorescent in situ hybridization (FISH), subcellular fractionation assay, a dual-luciferase reporter assay and rescue experiments were employed for further mechanistic investigation. RESULTS: The expression of circ_MAPK9 was significantly up-regulated in HCC tissues and cells, which was found to be associated with poor prognosis. Patients with high expression of circ_MAPK9 had a shorter overall survival and disease-free survival in comparison to those with low circ_MAPK9 expression. Functional assays showed that circ_MAPK9 knockdown suppressed cellular proliferation, migration, invasion and tumor growth in vivo, and promoted apoptosis in HCC cells. Moreover, we found that circ_MAPK9 knockdown could inhibit aerobic glycolysis by decreasing the production of adenosine triphosphate (ATP) and lactic acid, which was mediated by lactate dehydrogenase (LDHA). Mechanistically, circ_MAPK9 functioned as ceRNA via sponging miR-642b-3p and alleviated the inhibitory effect of miR-642b-3p on its target signal transducer and activator of transcription 3 (STAT3) and LDHA, thereby leading to STAT3 activation and LDHA expression. CONCLUSIONS: Circ_MAPK9, as an oncogene, promotes HCC growth and metastasis through miR-642b-3p/STAT3-LDHA axis. Circ_MAPK9 could serve as a potential biomarker for HCC poor prognosis and diagnosis.

Genomic alterations driving precancerous to cancerous lesions in esophageal cancer development.

Esophageal squamous cell carcinoma (ESCC) develops through a series of increasingly abnormal precancerous lesions. Previous studies have revealed the striking differences between normal esophageal epithelium and ESCC in copy number alterations (CNAs) and mutations in genes driving clonal expansion. However, due to limited data on early precancerous lesions, the timing of these transitions and which among them are prerequisites for malignant transformation remained unclear. Here, we analyze 1,275 micro-biopsies from normal esophagus, early and late precancerous lesions, and esophageal cancers to decipher the genomic alterations at each stage. We show that the frequency of TP53 biallelic inactivation increases dramatically in early precancerous lesion stage while CNAs and APOBEC mutagenesis substantially increase at late stages. TP53 biallelic loss is the prerequisite for the development of CNAs of genes in cell cycle, DNA repair, and apoptosis pathways, suggesting it might be one of the earliest steps initiating malignant transformation.

Comprehensive Analyses Reveal Effects on Tumor Immune Infiltration and Immunotherapy Response of APOBEC Mutagenesis and Its Molecular Mechanisms in Esophageal Squamous Cell Carcinoma.

The apolipoprotein B mRNA editing enzyme catalytic polypeptide (APOBEC) mutagenesis is prevalent in esophageal squamous cell carcinoma (ESCC). However, the functional role of APOBEC mutagenesis has yet to be fully delineated. To address this, we collect matched multi-omics data of 169 ESCC patients and evaluate characteristics of immune infiltration using multiple bioinformatic approaches based on bulk and single-cell RNA sequencing (scRNA-seq) data and verified by functional assays. We find that APOBEC mutagenesis prolongs overall survival (OS) of ESCC patients. The reason for this outcome is probably due to high anti-tumor immune infiltration, immune checkpoints expression and immune related pathway enrichment, such as interferon (IFN) signaling, innate and adaptive immune system. The elevated AOBEC3A (A3A) activity paramountly contributes to the footprints of APOBEC mutagenesis and is first discovered to be transactivated by FOSL1. Mechanistically, upregulated A3A exacerbates cytosolic double-stranded DNA (dsDNA) accumulation, thus stimulating cGAS-STING pathway. Simultaneously, A3A is associated with immunotherapy response which is predicted by TIDE algorithm, validated in a clinical cohort and further confirmed in mouse models. These findings systematically elucidate the clinical relevance, immunological characteristics, prognostic value for immunotherapy and underlying mechanisms of APOBEC mutagenesis in ESCC, which demonstrate great potential in clinical utility to facilitate clinical decisions.

Characterization of genomic alterations and neoantigens and analysis of immune infiltration identified therapeutic and prognostic biomarkers in adenocarcinoma at the gastroesophageal junction.

Objectives: Adenocarcinoma at the gastroesophageal junction (ACGEJ) refers to a malignant tumor that occurs at the esophagogastric junction. Despite some progress in targeted therapies for HER2, FGFR2, EGFR, MET, Claudin 18.2 and immune checkpoints in ACGEJ tumors, the 5-year survival rate of patients remains poor. Thus, it is urgent to explore genomic alterations and neoantigen characteristics of tumors and identify CD8+ T-cell infiltration-associated genes to find potential therapeutic targets and develop a risk model to predict ACGEJ patients' overall survival (OS). Methods: Whole-exome sequencing (WES) was performed on 55 paired samples from Chinese ACGEJ patients. Somatic mutations and copy number variations were detected by Strelka2 and FACETS, respectively. SigProfiler and SciClone were employed to decipher the mutation signature and clonal structure of each sample, respectively. Neoantigens were predicted using the MuPeXI pipeline. RNA sequencing (RNA-seq) data of ACGEJ samples from our previous studies and The Cancer Genome Atlas (TCGA) were used to identify genes significantly associated with CD8+ T-cell infiltration by weighted gene coexpression network analysis (WGCNA). To construct a risk model, we conducted LASSO and univariate and multivariate Cox regression analyses. Results: Recurrent MAP2K7, RNF43 and RHOA mutations were found in ACGEJ tumors. The COSMIC signature SBS17 was associated with ACGEJ progression. CCNE1 and VEGFA were identified as putative CNV driver genes. PI3KCA and TP53 mutations conferred selective advantages to cancer cells. The Chinese ACGEJ patient neoantigen landscape was revealed for the first time, and 58 potential neoantigens common to TSNAdb and IEDB were identified. Compared with Siewert type II samples, Siewert type III samples had significant enrichment of the SBS17 signature, a lower TNFRSF14 copy number, a higher proportion of samples with complex clonal architecture and a higher neoantigen load. We identified 10 important CD8+ T-cell infiltration-related Hub genes (CCL5, CD2, CST7, GVINP1, GZMK, IL2RB, IKZF3, PLA2G2D, P2RY10 and ZAP70) as potential therapeutic targets from the RNA-seq data. Seven CD8+ T-cell infiltration-related genes (ADAM28, ASPH, CAMK2N1, F2R, STAP1, TP53INP2, ZC3H3) were selected to construct a prognostic model. Patients classified as high risk based on this model had significantly worse OS than low-risk patients, which was replicated in the TCGA-ACGEJ cohort. Conclusions: This study provides new neoantigen-based immunotherapeutic targets for ACGEJ treatment and effective disease prognosis biomarkers.

Comprehensive Analysis of Differentially Expressed Long Noncoding RNA-mRNA in the Adenoma-Carcinoma Sequence of DNA Mismatch Repair Proficient Colon Cancer.

DNA proficient mismatch repair colon cancer (pMMR CC) is the most common subtype of sporadic CC. We aimed to investigate the role of long noncoding RNAs (lncRNAs) in pMMR CC carcinogenesis. In the present study, we conducted transcriptomic analysis of lncRNAs-mRNAs in five low-grade intraepithelial neoplasia (LGIN), five high-grade intraepithelial neoplasia (HGIN), four pMMR CC, and five normal control (NC) tissues. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment pathway, and coexpression network analyses were performed to elucidate the functions of lncRNAs and mRNAs as well as their interactions. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to validate five dysregulated lncRNAs in a large set of colon tissues. Receiver-operating characteristic (ROC) curves were employed to evaluate the performance of the candidate lncRNAs. A set of 5783 differentially expressed lncRNAs and 4483 differentially expressed mRNAs were detected among the LGIN, HGIN, pMMR CC, and NC samples. These differentially expressed lncRNAs and mRNAs were assigned to 275 significant GO terms and 179 significant KEGG enriched pathways. qRT-PCR confirmed that the expression of five selected lncRNAs (ENST00000521815, ENST00000603052, ENST00000609220, NR_026543, and ENST00000545920) were consistent with the microarray data. ROC analysis showed that four lncRNAs (ENST00000521815, ENST00000603052, ENST00000609220, and NR_026543) had larger area under the ROC curve (AUC) values compared to serum carcinoembryonic antigens, thereby distinguishing NC from pMMR CC. In conclusion, several lncRNAs play various roles in the adenoma-carcinoma sequence and may serve as potential biomarkers for the early diagnosis of pMMR CC.

Personal instruction for patients before colonoscopies could improve bowel preparation quality and increase detection of colorectal adenomas.

BACKGROUND: To analyze whether face-to-face education before colonoscopy improves the quality of bowel preparation and increases the detection of adenomas. METHODS: A retrospective cross-sectional study of adult patients with colorectal polyps identified by colonoscopy as outpatients was performed. The patients underwent an added colonoscopy inpatient for resection of colorectal polyps. As outpatients, we gave the patients written bowel preparation instructions; however, when they were inpatients, we supplied face-to-face education. We analyzed the data from the two colonoscopies of the same group of patients out- and in-patients, including the quality of the intestinal preparation, the time to reach the ileocecal region, and the detection of adenomas. RESULTS: A total of 260 patients {age 63 [56, 68] years old, male/female (169/91)} were retrospectively included in our study. Two hundred fifty-two patients with a total of 685 adenomas were detected, 94 patients with 179 adenomas overlooked in the first colonoscopy. The BBPS Score during inpatient was higher than that during outpatient, {9 [8, 9] vs. 7 [6, 9]}, P<0.05, the Bubble Score during inpatient was lower than that during outpatient [0 (0.00, 0.00) vs. 0 (0.00, 1.00)], P<0.05. The time to reach the ileocecal region during inpatient is shorter than that during outpatient {6 [5, 9] vs. 7.5 [5, 11] min}, P<0.05. Poor bowel preparation, flat adenoma morphology, and adenoma diameter lower than 5mm were related adenoma misdiagnoses, P<0.05. CONCLUSIONS: Face-to-face patient education can improve the quality of bowel preparation, then shorten the time to reach the ileocecal region, and increase detection of colorectal adenomas.

ADAMTS4 is upregulated in colorectal cancer and could be a useful prognostic indicator of colorectal cancer.

OBJECTIVE: ADAMTS4 is a member of the ADAMTS4 family, which secretes proteinases. The mechanism of tumor metastasis may be correlated to its promotion of angiogenesis. It was determined whether ADAMTS4 participates in colorectal cancer progression. METHODS: The expression in clinical samples and CRC cell lines was investigated. Using immunohistochemistry (IHC), fluorescence in situ hybridization (FISH), and RT-PCR, the expression of ADAMTS4 was determined in colorectal tumors of different cancer stages and anatomic sites, and in three cell lines of different aggressiveness. RESULTS: The overexpression of ADAMTS4 was observed in tissue samples by IHC, and this was mainly located in the cytoplasm, as detected by FISH. The qRT-PCR and western blot analyses further supported the clinical sample findings. CONCLUSION: The present data support the notion that the overexpression of ADAMTS4 in CRC might be useful as a non-invasive biomarker for detecting CRC in patients.

ADAMTS4 is upregulated in colorectal cancer and could be a useful prognostic indicator of colorectal cancer

SUMMARY OBJECTIVE ADAMTS4 is a member of the ADAMTS4 family, which secretes proteinases. The mechanism of tumor metastasis may be correlated to its promotion of angiogenesis. It was determined whether ADAMTS4 participates in colorectal cancer progression. Methods The expression in clinical samples and CRC cell lines was investigated. Using immunohistochemistry (IHC), fluorescence in situ hybridization (FISH), and RT-PCR, the expression of ADAMTS4 was determined in colorectal tumors of different cancer stages and anatomic sites, and in three cell lines of different aggressiveness. Results The overexpression of ADAMTS4 was observed in tissue samples by IHC, and this was mainly located in the cytoplasm, as detected by FISH. The qRT-PCR and western blot analyses further supported the clinical sample findings. Conclusion The present data support the notion that the overexpression of ADAMTS4 in CRC might be useful as a non-invasive biomarker for detecting CRC in patients.

RESUMO OBJETIVO ADAMTS4 é um membro da família ADAMTS4, que secreta proteinases. O mecanismo da metástase do tumor pode ser correlacionado a sua promoção da angiogênese. Determinou-se se ADAMTS4 participa na progressão do câncer colorretal. Métodos A expressão em amostras clínicas e linhas de células CRC foi investigada. Usando a imuno-histoquímica (IHC), a hibridação fluorescente in situ (HFIS) e o RT-PCR, a expressão de ADAMTS4 foi determinada em tumores colorretais de diferentes estágios do câncer e locais anatômicos, e em três linhas de células de níveis de agressividade distintos. Resultados A superexpressão de ADAMTS4 foi observada em amostras de tecido por IHC, e esta foi localizada principalmente no citoplasma, como detectado pelo HFIS. O qRT-PCR e a análise de wester blot corroboraram os resultados clínicos da amostra. Conclusão Os dados atuais corroboram a noção de que a superexpressão de ADAMTS4 no CRC pode ser útil como um biomarcador não invasivo para a detecção de CRC em pacientes.

Long noncoding RNA ENST00000455974 plays an oncogenic role through up-regulating JAG2 in human DNA mismatch repair-proficient colon cancer.

DNA mismatch repair-proficient colon cancer is the most common type of colon cancer, but its initiation and progression are still unknown. Our previous study has revealed that a long noncoding RNA (lncRNA) ENST00000455974 was significantly associated with TNM stage and distant metastasis in patients with DNA mismatch repair-proficient (pMMR) colon cancer (CC). Here, firstly, we observed that ENST00000455974 was gradual increased across colon normal-adenoma-carcinoma-metastasis sequence by quantitative real-time PCR. Secondly, ENST00000455974 showed a better sensitivity and specificity than CEA and CA19-9 in the diagnosis of pMMR CC by drawing the receiver operating characteristic (ROC) curve. Thirdly, a higher level of ENST00000455974 was associated with a poorer patient survival. Furthermore, Knockdown of ENST00000455974 led to reduced proliferation and migration of colon cancer cells. Mechanistically, ENST00000455974 was mainly located in the nucleus of colon cancer cells and it promoted the growth and metastasis of pMMR CC cells through up-regulating JAG2.

Variable Levels of Long Noncoding RNA Expression in DNA Mismatch Repair-Proficient Early-Stage Colon Cancer.

BACKGROUND: Long noncoding RNAs (lncRNAs) have been suggested to be biomarkers for diagnosis and prognosis of sporadic colorectal cancer. AIMS: This study aimed to characterize the expression profile of lncRNAs in DNA mismatch repair-proficient (pMMR) early-stage colon cancer (CC). METHODS: The microsatellite instability (MSI) status was examined by a multiplex PCR. The expression of lncRNA and mRNA was analyzed by microarrays. The differentially expressed lncRNAs and mRNAs were determined by bioinformatic analyses and validated in 44 CC samples and 32 non-tumor colonic specimens by quantitative real-time polymerase chain reaction (qRT-PCR). RESULTS: We found that 16 out of 67 CC had MSI-L CC and 7 with MSI-H. In comparison with that in five non-tumor colonic samples, microarray indicated that 1492 lncRNAs and 1639 mRNAs were upregulated while 1804 lncRNAs and 1073 mRNAs downregulated in four pMMR early-stage CC. Bioinformatic analyses revealed that the differentially expressed mRNAs were involved in the process of cell division, angiogenesis, apoptotic, differentiation, the PI3K-Akt/p53/TNF pathways and others. The co-expression lncRNA and mRNA networks indicated five hot spots with significantly high co-expression degrees. Further quantitative RT-PCR revealed that 4 out of 6 lncRNAs were significantly upregulated while the other 2 lncRNAs were downregulated in the CC. Stratification analysis demonstrated that 5 out of 6 lncRNAs were significantly associated with TNM stage and/or distant metastasis in this population. CONCLUSION: Differentially expressed lncRNAs were significantly associated with clinical features of patients with pMMR CC and may participate in the tumorigenesis of pMMR CC.