A microarray expression profile and bioinformatic analysis of circular RNA in human esophageal carcinoma.

Background: Recent studies indicate that non-coding circular RNAs (circRNAs) are involved in the development of esophageal carcinoma (EC). This study aimed to identify differential expression of circRNAs in EC, which can provide potential biomarkers and therapeutic targets for EC treatment and improve the understanding of tumorigenesis mechanism. Methods: First, samples (n=5) of EC tissues and adjacent normal tissue were sent for circRNA microarray detection, Second, further bioinformatic analysis was performed, including circRNA-microRNA (miRNA), co-expression network analysis, Spearman correlation test, and cancer-related circRNA-miRNA axis analysis. Finally, the expression of circRNA that our analysis predicted to be hub genes was verified in samples (n=15) of EC tissues and adjacent normal tissue by real-time polymerase chain reaction (RT-PCR). Results: Microarray identified 102 upregulated and 67 significantly downregulated circRNAs were in EC patients' tumors relative to adjacent normal tissue. One upregulated circRNA (hsa_circRNA_401955) showed the most connection with MREs, therefore was regarded as the hub gene by the Spearman correlation test. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses showed that four primary pathways (mRNA surveillance, cytoskeleton actin regulation, spliceosome, and the NOD-like receptor signaling pathway) were predicted in the hub circRNA's five connected miRNA response elements (MREs). Furthermore, cancer-related circRNA-miRNA axis analyses showed that hsa_circRNA_100375 and its four connected MREs participated in the cancer-related pathway. RT-PCR showed that hsa_circRNA_100375 and hsa_circRNA_401955 were significantly increased in the tumor tissues of EC patients. Conclusions: Abnormal expression of circRNAs was involved in the tumorigenesis of EC. Key circRNAs, namely hsa_circRNA_401955 and hsa_circRNA_100375, may be as potential biomarkers and therapeutic targets for the treatment of EC.

Isoangustone A induces autophagic cell death in colorectal cancer cells by activating AMPK signaling.

Phytochemicals, especially flavonoids, have been widely investigated for their diversified pharmacological activities including anticancer activities. Previously we identified isoangustone A from licorice-derived compounds as a potent inducer of cell death. In the present study, the exact mechanism by which isoangustone A induced cell death was further investigated, with autophagy as an indispensible part of this process. Isoangustone A treatment activated autophagic signaling and induced a complete autophagic flux in colorectal cancer cells. Knockdown of ATG5 or pre-treatment with autophagy inhibitors significantly reversed isoangustone A-induced apoptotic signaling and loss of cell viability, suggesting autophagy plays an important role in isoangustone A-induced cell death. Isoangustone A inhibited Akt/mTOR signaling, and overexpressing of a constitutively activated Akt mildly suppressed isoangustone A-induced cell death. More importantly, isoangustone A inhibited cellular ATP level and activated AMPK, and pre-treatment with AMPK inhibitor or overexpression of dominant negative AMPKα2 significantly reversed isoangustone A-induced autophagy and cell death. Further study shows isoangustone A dose-dependently inhibited mitochondrial respiration, which could be responsible for isoangustone A-induced activation of AMPK. Finally, isoangustone A at a dosage of 10 mg/kg potently activated AMPK and autophagic signaling in and inhibited the growth of SW480 human colorectal xenograft in vivo. Taken together, induction of autophagy through activation of AMPK is an important mechanism by which isoangustone A inhibits tumor growth, and isoangustone A deserves further investigation as a promising anti-cancer agent.

Analysis of the function of MAGE-A in esophageal carcinoma by bioinformatics.

BACKGROUND: Melanoma-associated antigen-A (MAGE-A) was recognized as high-expressed in many solid tumors including esophageal carcinoma (EC), nevertheless, was reported to be low/not-expressed in normal tissues. Thus, it was considered as an extraordinary appropriate target for treatment especially in immunotherapy. Therefore, it demanded more detail knowledge on the precise function of MAGE-A. METHODS: In this study, we used the data from the Cancer Genome Atlas dataset (TCGA-ESCA) to analyze the expression and survival for MAGE A3/4/11 (the subtype of MAGE-A) using the online tool of UALCAN. Furthermore, the high-throughput sequencing data of the patients with esophageal squamous-cell carcinoma (ESCC) from TCGA dataset were performed to analyze the correlation test, gene ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment of MAGE A3/4/9/11 using LinkeDomics (online tool) and ClueGO (inner software of Cytoscape). Finally, relative gene expressions of MAGE A3/4/9/11 were verified by quantitative real-time PCR (q-PCR) in the patients with EC. RESULTS: MAGE A3/4/11 was high-expressed in tissues of patients with ESCC, and there was no difference in survival time for patients between the high-expressed with the low/medium-expressed. The Go enrichment analysis showed that the 4 MAGE-A subtypes (MAGE-A3/4/9/11) were enriched in the regulation of the adaptive immune response, translational initiation, interleukin-4 production, response to type I interferon, and skin development, respectively. The KEGG results showed that they were enriched in T cell receptor signaling pathway (MAGE-A3), Th1 and Th2 differentiation, antigen processing and presentation (MAGE-A4), cytokine-cytokine receptor interaction (MAGE-A9), and chemokine signaling pathway (MAGE-A11). CONCLUSION: MAGE A3/4/9/11 was high-expressed in EC, and were enrolled in the regulation of immune response. They may consider as candidate immune target for EC treatment and provided the messages for further research in the function of MAGE-A.

MicroRNA­21 regulates the biological behavior of esophageal squamous cell carcinoma by targeting RASA1.

MicroRNA­21 (miR­21) has been revealed to play a crucial role in regulating the biological behavior, including proliferation, migration, invasion and metastasis in certain cancers. However, its role in esophageal squamous cell carcinoma (ESCC) has yet to be elucidated. Based on the data of GSE13937 downloaded from Gene Expression Omnibus (GEO) database, miR­21 was revealed to be one of the top 20 differentially expressed (DE) miRNAs screened using the Morpheus online tool. RAS p21 protein activator 1 (RASA1) was predicted as the target gene of miR­21 using the predicting software and was combined with miR­21 using the luciferase reporter assay. Its relative expression was significantly decreased, however, miR­21 was increased in the tumor tissues compared to the normal adjacent tissues in patients with ESCC as determined by quantitative polymerase chain reaction (q­PCR). Furthermore, overexpression of miR­21 (mimic) could significantly decrease the gene level of RASA1. Conversely, downregulation of miR­21 (inhibitor) significantly increased the gene level of RASA1, while downregulation of RASA1 (siRASA1) markedly increased the gene expression of miR­21. Notably, the expression of Snail and vimentin were significantly increased by upregulation of miR­21 and downregulation of RASA1. Transwell results revealed that miR­21 and RASA1 regulated proliferation, migration and invasion in ESCC cells. In an in vivo model, miR­21 inhibitor (antagomir) could inhibit tumor growth. In conclusion, miR­21 regulated cell proliferation, migration, invasion and tumor growth of ESCC by directly targeting RASA1, which may have been achieved via regulation of Snail and vimentin. Anti­miR­21 revealed an antitumor effect. Thus, it may be considered as a possible target for ESCC therapy.

Identification of key genes and pathways for esophageal squamous cell carcinoma by bioinformatics analysis.

The aim of the present study was to identify the differentially expressed genes (DEGs) in esophageal squamous-cellcarcinoma (ESCC) and provide potential therapeutic targets. The microarray dataset GSE20347 was downloaded from the Gene Expression Omnibus (GEO) database, and included 17 tissue samples and 13 normal adjacent tissue samples from patients with ESCC. A total of 22,277 DEGs were identified. A heat map for the DEGs was constructed with the Morpheus online tool and the top 200 genes (100 upregulated and 100 downregulated) were selected for further bioinformatics analysis, including analysis of gene ontology (GO) terms, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, protein-protein interaction networks and Spearman's correlation tests. The results of the GO analysis indicated that the upregulated DEGs were most significantly enriched in membrane-bounded vesicles in the cellular component (CC) category, but were not significantly enriched in any GO terms of the categories biological process (BP) or molecular function (MF); furthermore, the downregulated DEGs were most significantly enriched in regulation of DNA metabolic processes, nucleotide binding and chromosomes in the categories BP, MF and CC, respectively. The KEGG analysis indicated that the downregulated DEGs were enriched in the regulation of cell cycle pathways. The top 10 hub proteins in the protein-protein interaction network were cyclin-dependent kinase 4, budding uninhibited by benzimidazoles 1, cyclin B2, heat shock protein 90AA1, aurora kinase A, H2A histone family member Z, replication factor C subunit 4, and minichromosome maintenance complex component 2, -4 and -7. These proteins are mainly involved in regulating tumor progression. The genes in the four top modules were mainly implicated in regulating cell cycle pathways. Secreted Ly-6/uPAR-related protein (SLURP) was the hub gene, and SLURP and its interacting genes were most enriched in the chromosomal part in the CC category, organelle organization in the BP category and protein binding in the MF category, and were involved in pathways including DNA replication, cell cycle and P53 signaling. The expression of SLURP-1 in fifteen patients with esophageal carcinoma was detected using quantitative polymerase chain reaction analysis, and the results indicated that SLURP-1 expression was significantly decreased in the tumor samples relative to that in normal adjacent tissues. These results suggest that several hub proteins and the hub gene SLURP-1 may serve as potential therapeutic targets, and that gene dysfunction may be involved in the tumorigenesis of ESCC.

Analysis of the function of microRNA-375 in humans using bioinformatics.

MicroRNA-375 (miR-375) is expressed at low levels in many types of solid tumor, particularly in gastrointestinal tumors. It is considered to be important in the development of cancer and certain diseases. Thus, more detailed knowledge is required on the particular functions of miR-375. miRs function by regulating target genes. Therefore, in the current study, miRWalk (which includes the data from 10 prediction software programs) was used to predict the target genes of miR-375. The genes, which were co-predicted using five different software programs were further analyzed using Database for Annotation, Visualization and Integrated Discovery online software [including gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis]. Subsequently, the online tool, Search Tool for the Retrieval of Interacting Genes, was used to analyze the protein-protein interaction and construct modules using Cytoscape. The result demonstrated 6,574 predicted genes, 1,325 of which were co-predicted. The GO analysis result indicated that, in biological processes, the co-predicted genes were significantly enriched in the regulation of nervous system development and cell differentiation, and the highest enrichment of molecular function was ion binding. In KEGG analysis, the genes were enriched in the Hippo signaling pathway, glutamatergic synapse, circadian entrainment and the phosphoinositide 3-kinase (PI3K)-Akt signaling pathway. The top 10 hub proteins were mechanistic target of rapamycin, PH domain and leucine rich repeat protein phosphatase 1, ubiquitously transcribed tetratricopeptide repeat containing, Y-linked, histone deacetylase 2, F-box and leucine rich repeat protein 19, KIT proto-oncogene receptor tyrosine kinase, angiotensinogen, Janus kinase 2, fibroblast growth factor 2 and RNA polymerase II subunit A. These proteins predominantly regulate the development and progression of cancer, hypertension, essential thrombocythemia and inflammation. The genes in the top seven modules selected were identified to be primarily enriched in chemokines, extracellular matrix-receptor interaction, focal adhesion, the PI3K-Akt signaling pathway, amoebiasis and protein processing signaling pathway. Thus, the target genes and hub proteins that were predicted in the current study were identified to be important in regulating the development and progression of cancer and certain diseases. Furthermore, they present potential novel biomarkers for tumor diagnosis and candidate targets for treatment, and indicate that further research is required to establish the functions of miR-375.

Treatment of medullary thyroid carcinoma with apatinib: A case report and literature review.

RATIONALE: Medullary thyroid carcinoma (MTC) is a rare type thyroid carcinoma originating from the thyroid parafollicular cells (C cells). Chemotherapy has a limited efficacy for treating persistent or recurrent MTC. PATIENT CONCERNS: A 46-year-old woman who underwent thyroidectomy for MTC in December 2007. She began experience recurring diarrhea in January 2015 and started to cough and feel shortness of breath in March 2016. DIAGNOSES: A chestcomputed tomography (CT) scan showed metastases in the bilateral lungs, pulmonary hilum, and mediastinal lymph nodes. Percutaneous biopsy of the pulmonary occupying lesions performed on March 21, 2016 indicated medullary carcinoma metastases at the right pulmonary hilum. INTERVENTIONS: This patient was treated with oral apatinib (500 mg daily). OUTCOMES: The patient's symptoms of diarrhea, coughing, and shortness of breath disappeared. CT reexaminations for efficacy assessment at 1, 2, and 3 months after the treatment indicated partial remission. Systemic migrating bone and joint pains occurred during the treatment, which were considered to be adverse events of apatinib. LESSONS: Treatment of MTC with apatinib has been shown to be effective in our case. Tyrosine kinase inhibitors (TKIs) that suppress rearranged during transfection (RET) and vascular endothelial growth factor receptor (VEGFR) should be considered as a effective therapeutic approaches.

[Proteinchip-flight mass spectrometry for screening differentially expressed proteins in the serum of cervical cancer patients].

OBJECTIVE: To identify the differentially expressed proteins in the serum of patients with cervical cancer for use as the biomarkers for early diagnosis of cervical cancer. METHODS: Surface-enhanced laser desorption/ionization time of flight mass spectrometry (SELDI-TOF-MS) with weak cationic chips (CM10) was used to examine the serum samples of 24 patients with cervical squamous cell carcinoma and 25 age-matched healthy women. The protein fingerprints were obtained, and bioinformatic analysis was performed to identify the differentially expressed proteins in the serum of the patients. RESULTS: Fifty-two differentially expressed proteins were detected in the serum of cervical cancer patients (P<10(-5)), among which 6 proteins with mass/charge ratio of 4173.77, 5903.09, 6087.12, 10716.9, 6109.61 and 3397.41, respectively, showed lowered expression in the serum of cervical cancer patients. Two diagnostic models for cervical cancer were generated using software, including one consisting of the 4173.77(M/Z) protein with the diagnostic specificity of 96% and sensitivity of 75% for cervical cancer and the other consisting of 3 proteins at 5335.81(M/Z), 7562.99(M/Z), and 9287.89(M/Z) with specificity of 91.67% and sensitivity of 96.0%. CONCLUSION: Cervical cancer patients show different serum protein expression profile from healthy women. The 6 differential proteins identified may serve as specific serum biomarkers in close relation to the origin and progression of cervical cancer.