Circular RNA (circRNA) is a novel class of single-stranded RNAs with a closed loop structure. The majority of circRNAs are formed by a back-splicing process in pre-mRNA splicing. Their expression is dynamically regulated and shows spatiotemporal patterns among cell types, tissues and developmental stages. CircRNAs have important biological functions in many physiological processes, and their aberrant expression is implicated in many human diseases. Due to their high stability, circRNAs are becoming promising biomarkers in many human diseases, such as cardiovascular diseases, autoimmune diseases and human cancers. In this review, we focus on the translational potential of using human blood circRNAs as liquid biopsy biomarkers for human diseases. We highlight their abundant expression, essential biological functions and significant correlations to human diseases in various components of peripheral blood, including whole blood, blood cells and extracellular vesicles. In addition, we summarize the current knowledge of blood circRNA biomarkers for disease diagnosis or prognosis.
Autoimmune Diseases/blood* ; Biomarkers, Tumor/blood* ; Cardiovascular Diseases/blood* ; Humans ; Liquid Biopsy ; Neoplasms/blood* ; RNA, Circular/blood* ; RNA, Neoplasm/blood*

This study was aimed to explore the transcription level of WT1 and PRAME two genes in bone marrow and peripheral blood samples of patients with myelodysplastic syndrome(MDS) and their relationship with bone marrow dysplasia and karyotype. The quantitative expression of WT1 and PRAME transcripts detected by RQ-PCR in the bone marrow samples of 203 MDS patients and 19 aplastic anemia(AA), 6 other benign anemia(BA), 4 paroxysmal nocturnal hemoglobinuria(PNH) patients from July 2009 to June 2012 and 14 healthy donors, and in 92 peripheral blood samples. The results showed that WT1 and PRAME expression levels in both BM and PB samples of MDS group were higher than those in normal controls, AA, and BA patients (BM: WT1:P = 0.000, 0.000, 0.000, PRAME: P = 0.048, 0.000, 0.064; PB: WT1:P = 0.012, 0.000, 0.011, PRAME: P = 0.020, 0.004, 0.003). What is more, this expression in high risk MDS group (RAEB1, RAEB2, MDS-AML) were higher than those in low risk group (RCUD, RCMD, MDS-U) and AA and BA. The WT1 and PRAME mRNA expression levels in PB and BM were well correlated (WT1:r = 0.6028, P = 0.001; PRAME: r = 0.7628, P = 0.000), as well as the WT1 expression levels in BM samples with the Karyotype (P = 0.049). In addition, the same positive rate of WT1 or PRAME expression existed in BM and PB samples of MDS patients. It is concluded that the WT1 and PRAME gene expression levels in both BM and PB samples of MDS patients are higher than those in healthy controls, AA and other benign anemia patients, and increase with the progression of the disease. The WT1 and PRAME transcripts constitute good molecular markers for the clinical diagnosis and prognosis and monitoring minimal residual disease after treatment of MDS. What is more, when bone marrow is not so convenient to get, the transcript levels of PB samples can be detected.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Antigens, Neoplasm ; genetics ; metabolism ; Bone Marrow ; metabolism ; Case-Control Studies ; Child ; Child, Preschool ; Female ; Humans ; Male ; Middle Aged ; Myelodysplastic Syndromes ; blood ; genetics ; metabolism ; Neoplasm, Residual ; diagnosis ; Prognosis ; RNA ; genetics ; WT1 Proteins ; genetics ; metabolism ; Young Adult

OBJECTIVETo construct glypican-3 (GPC-3) short hairpin RNA (shRNA) and investigate the effects of GPC-3 transcription silencing on hepatoma cell invasion and angiogenesis mechanisms.

METHODSGPC-3-specific shRNA and non-target control shRNA were constructed and transfected into the human hepatoma cell lines HepG2, MHCC-97H, and Huh7. shRNA-mediated silencing of GPC-3 expression was confirmed at the mRNA and protein levels by fluorescence quantitative reverse transcription (FQRT)-PCR and western blotting, respectively. The effect of silenced GPC-3 expression on cell proliferation was detected by EdU and sulforhodamine B assays, on migration by wound healing (scratch) assay, on invasion by transwell chamber assay, and on apoptosis by luminescence assay of caspase-3/7 activity. The effect of silenced GPC-3 expression on angiogenesis-related signaling factors was detected by FQRT-PCR (for the glioma-associated oncogene homolog-1 hedgehog signaling factor, GLI1, and the beta-catenin Wnt signaling factor, b-catenin), immunofluorescent staining (for the insulin-like growth factor-II, IGF-II), and ELISA (for the vascular endothelial growth factor, VEGF). Pairwise comparisons were made by the independent sample t-test, and multiple comparisons were made by one-way ANOVA.

RESULTSIn all cell lines, transfection with the GPC-3-specific shRNA significantly reduced GPC-3 mRNA levels (% reduction as compared to the non-target control shRNA: HepG2, 89.2+/-6.0%, t = -25.753, P less than 0.001; MHCC-97H, 75.3+/-4.9%, t = -26.487, P less than 0.001; Huh7, 73.6+/-4.6%, t = -27.607, P less than 0.001); the GPC-3 protein levels were similarly reduced. The GPC-3 shRNA-silenced cells showed significantly reduced proliferative, migratory and invasive capacities, as well as significantly increased apoptosis. The shRNA-mediated GPC-3 silencing was accompanied by significant down-regulation of b-catenin mRNA (HepG2, 46.9+/-0.6%; MHCC-97H, 67.5+/-2.7%; Huh7, 56.3+/-8.4%) and significant up-regulation of GLI1 mRNA (HepG2, 49.2+/-28.6%; MHCC-97H, 54.6+/-24.4%; Huh7, 31.6+/-15.7%). At 72 h after transfection, the HepG2 cells showed significant down-regulation of VEGF protein (54.3+/-1.5%, t = 46.746, P less than 0.001).

CONCLUSIONGPC-3 contributes to migration, invasion, angiogenesis, and apoptosis of hepatoma cells, possibly through its interactions with the Wnt/b-catenin and Hedgehog signaling pathways. GPC-3 may represent a useful target for gene silencing by molecular-based therapies to treat hepatocellular carcinoma.

Apoptosis ; Carcinoma, Hepatocellular ; blood supply ; metabolism ; pathology ; Caspase 3 ; metabolism ; Cell Line, Tumor ; Gene Silencing ; Glypicans ; genetics ; Humans ; Liver Neoplasms ; blood supply ; metabolism ; pathology ; Neoplasm Invasiveness ; Neovascularization, Pathologic ; RNA, Messenger ; genetics ; metabolism ; RNA, Small Interfering ; genetics ; Signal Transduction ; Transfection ; Vascular Endothelial Growth Factor A ; metabolism ; beta Catenin ; metabolism

Angiogenesis, the expansion of preexisting blood vessels, is a complex process required for tumor growth and metastasis. Although current antiangiogenic strategies have shown promising results in several cancer types, identification of additional antiangiogenic targets is required to improve the therapeutic response. Herein, we show that the microtubule-binding protein CLIP-170 (cytoplasmic linker protein of 170 kDa) is highly expressed in breast tumor samples and correlates positively with blood vessel density. Depletion of CLIP-170 significantly impaired vascular endothelial tube formation and sprouting in vitro and inhibited breast tumor growth in mice by decreasing tumor vascularization. Our data further show that CLIP-170 is important for the migration but not the proliferation of vascular endothelial cells. In addition, CLIP-170 promotes the polarization of endothelial cells in response to the angiogenic stimulus. These findings thus demonstrate a critical role for CLIP-170 in tumor angiogenesis and suggest its potential as a novel antiangiogenic target.
Animals ; Breast Neoplasms ; blood supply ; metabolism ; pathology ; Cell Line, Tumor ; Cell Movement ; Cell Polarity ; Female ; Human Umbilical Vein Endothelial Cells ; Humans ; MCF-7 Cells ; Mice ; Mice, Nude ; Microtubule-Associated Proteins ; antagonists & inhibitors ; genetics ; metabolism ; Microtubules ; metabolism ; Neoplasm Proteins ; antagonists & inhibitors ; genetics ; metabolism ; Neovascularization, Pathologic ; RNA Interference ; RNA, Small Interfering ; metabolism ; Transplantation, Heterologous

OBJECTIVETo evaluate the expression of BRCA1, ERCC1, TUBB3 and PRR13 mRNA and their relationship with clinical chemosensitivity in primary ovarian cancer, and to assess the predictive value of joint detection of both BRCA1 and ERCC1 genes for the treatment of primary ovarian cancer.

METHODSPrimary epithelial ovarian tumor samples were collected from 46 patients who underwent cytoreductive surgery. Real-time quantitative PCR was used to analyze the relative expression of BRCA1, ERCC1, TUBB3 and PRR13 mRNA in those cases. The correlation of clinical chemosensitivity and the test results was statistically analyzed. The efficacy of the joint prediction of clinical chemosensitivity by combining the two drug resistance gene detection was evaluated.

RESULTSThe BRCA1 mRNA relative expression logarithm in the clinical-resistant group was 0.673±2.143, and clinical-sensitive group -1.436±2.594 (P=0.008). The ERCC1 mRNA relative expression logarithm in the clinical-resistant group was -0.529±1.982 and clinical-sensitive group -3.188±2.601 (P=0.001). BRCA1 and ERCC1 expression level is negatively correlated with platinum-based chemosensitivity. The PRR13 expressions in the two groups were not significantly different (P=0.074), and the TUBB3 expressions between the two groups were also not significantly different (P=0.619). When the intercept point value BRCA1 mRNA expression logarithm was -0.6, the predictive sensitivity, specificity, positive predictive value and negative predictive value were 73.3%, 75.0%, 84.6% and 60.0%, respectively, with the best comprehensive assessment. When the intercept point value of ERCC1 mRNA expression logarithm was -1, the predictive sensitivity, specificity, positive predictive value and negative predictive value were 80.0%, 68.8%, 82.8% and 64.7%, respectively, with the best comprehensive assessment. The combination detection of BRCA1 and ERCC1 can improve the chemotherapeutic sensitivity, specificity, positive predictive value and negative predictive value to 86.7%, 68.8%, 83.9% and 73.3%, respectively.

CONCLUSIONSBRCA1 and ERCC1 mRNA expression has a negative correlation with the clinical sensitivity of platinum-based chemotherapy. Combination detection of the two drug-resistance associated genes can improve the predictive efficacy of ovarian cancer chemosensitivity and beneficial to individual treatment of ovarian cancer.

Antineoplastic Combined Chemotherapy Protocols ; therapeutic use ; BRCA1 Protein ; genetics ; metabolism ; CA-125 Antigen ; blood ; Carboplatin ; administration & dosage ; DNA-Binding Proteins ; genetics ; metabolism ; Drug Resistance, Neoplasm ; Endonucleases ; genetics ; metabolism ; Female ; Gene Expression Regulation, Neoplastic ; Humans ; Neoplasms, Glandular and Epithelial ; drug therapy ; metabolism ; surgery ; Ovarian Neoplasms ; drug therapy ; metabolism ; surgery ; Paclitaxel ; administration & dosage ; RNA, Messenger ; metabolism ; Repressor Proteins ; genetics ; metabolism ; Tubulin ; genetics ; metabolism

OBJECTIVETo explore the clinical significance of cytokeratin 19 fragments test in the diagnosis of nasopharyngeal carcinoma.

METHODSThe study included 102 cases of nasopharyngeal carcinoma, 90 cases of nasal polyp/nasopharyngitis, and 150 healthy individuals. RT-PCR was used to detect CK19 mRNA expression and Western blot to detect CK19 fragment protein expression in tissues of nasopharyngeal carcinoma. Expression of CK19-2G2 was examined by immunohistochemistry. Chemiluminescence analysis was used to detect the serum levels of CK19-2G2, and ELISA to detect that of EB-VCA IgA.

RESULTSAmong 102 cases of nasophryngeal carcinoma, 64 showed CK19 mRNA expression by RT-PCR, 60 showed CK19 protein fragments in tumor tissues by Western blot, and 66 showed expression of CK19-2G2 by immunohistochemistry in nasopharyngeal carcinoma, including strong positivity in 20 cases, moderate in 34 cases and weak in 12 cases. The sensitivity and specificity of CK19-2G2 in the diagnosis of nasopharyngeal carcinoma were 49.0% and 89.2%, and those of EB-VCA IgA were 52.9% and 85.4%, respectively. The combined detection of CK19-2G2 and EB-VCA IgA increased the sensitivity to 73.5% while the specificity remained at 80.0%.

CONCLUSIONSHigh levels of CK19-2G2 fragment expressed in tissue and serum are present in patients with nasopharyngeal carcinoma. The serum level of CK19-2G2 is helpful in the diagnosis of nasopharyngeal carcinoma. Furthermore, the combination of serum CK19-2G2 and EB-VCA IgA improves the detection sensitivity.

Adult ; Aged ; Antigens, Viral ; blood ; Blotting, Western ; Capsid Proteins ; blood ; Carcinoma, Squamous Cell ; diagnosis ; metabolism ; pathology ; Herpesvirus 4, Human ; immunology ; Humans ; Immunoglobulin A ; blood ; Immunohistochemistry ; Keratin-19 ; blood ; metabolism ; Middle Aged ; Nasopharyngeal Neoplasms ; diagnosis ; metabolism ; pathology ; Neoplasm Staging ; Peptide Fragments ; blood ; metabolism ; RNA, Messenger ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Sensitivity and Specificity

OBJECTIVETo explore the relationship between hypoxia-inducible factor-1α (HIF-1α) mRNA levels in the peripheral blood and the metastasis of colorectal cancer.

METHODSHIF-1α mRNA in the peripheral blood was detected by RT-PCR in 40 patients with colorectal cancer and 20 healthy subjects.

RESULTSSeventeen patients with colorectal cancer showed positivity for HIF-1α mRNA, showing a significantly higher positivity rate (42.5%) than the healthy subjects (P<0.05). The expression of HIF-1α mRNA is closely related to the staging of colorectal cancer (CRC).

CONCLUSIONHIF-1α mRNA may serve as a potential marker in the detection of metastasis of colorectal cancer.

Adenocarcinoma ; blood ; pathology ; Adult ; Aged ; Aged, 80 and over ; Case-Control Studies ; Colorectal Neoplasms ; blood ; pathology ; Female ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; blood ; genetics ; Male ; Middle Aged ; Neoplasm Invasiveness ; Neoplasm Metastasis ; RNA, Messenger ; genetics

OBJECTIVETo explore the role of oxidative stress and the antioxidant protein thioredoxin in the tumorigenesis and progression of gastric cancer.

METHODSThe plasma levels of adenosine deaminase (ADA), glutathione peroxidase (GPX), superoxide dismutase (SOD), and advanced oxidation protein products (AOPP) were determined by colorimetry, and the plasma levels of thioredoxin were determined by enzyme-linked immunosorbent assay (ELISA) in 48 gastric cancer patients and 30 healthy subjects. RT-PCR assay was employed to examine the expression levels of thioredoxin mRNA in the tissue samples of the patients.

RESULTSCompared with the healthy controls, patients with gastric cancer had significantly increased plasma levels of ADA and AOPP (P<0.05), decreased plasma GPX level (P<0.05), and similar plasma SOD levels. The plasma levels of thioredoxin were significantly higher in patients with gastric cancer than in the healthy controls (P<0.05). Thioredoxin levels was not associated with gender, age, degree of tumor cell differentiation, invasion depth, or lymph node metastasis (P>0.05), but was correlated to distant tumor metastasis (P<0.05). The expression of Trx mRNA was significantly higher in gastric carcinoma than in normal gastric tissue (P<0.05).

CONCLUSIONGastric cancer patients have high levels of oxidative stress and thioredoxin expression, and the latter is related to distant metastasis of the tumor.

Adenosine Deaminase ; blood ; Adult ; Advanced Oxidation Protein Products ; blood ; Aged ; Case-Control Studies ; Female ; Glutathione Peroxidase ; blood ; Humans ; Male ; Middle Aged ; Neoplasm Metastasis ; Oxidative Stress ; RNA, Messenger ; genetics ; Stomach Neoplasms ; metabolism ; pathology ; Superoxide Dismutase ; blood ; Thioredoxins ; genetics ; metabolism

Adult ; Aged ; Carcinoma, Non-Small-Cell Lung ; metabolism ; pathology ; Female ; Humans ; Lung Neoplasms ; metabolism ; pathology ; Lymph Nodes ; metabolism ; pathology ; Lymphatic Metastasis ; Male ; Middle Aged ; Neoplasm Staging ; RNA, Messenger ; metabolism ; Vascular Endothelial Growth Factor C ; blood ; genetics ; metabolism

OBJECTIVE: To explore clinical evaluate of CK19 mRNA and EGFR mRNA for diagnosis of laryngeal carcinoma micrometastasis, correlation between circulation tumor cell and lymph node metastasis. METHOD: Of 30 nude mice, 25 were randomly divided into 5 experimental groups (5 mice in each group), 5 were acted as control group. The mice were killed 2,4,6,8 and 10 weeks after injection. The expression of CK19 and EGFR mRNA in the peripheral blood and tumor tissue were detected by RT-PCR assay. The expression of EGFR in tumor tissue were detected by immunohistochemistry and lymph node transfer were confirmed using continuous pathological dying. RESULT: None of CK19 and EGFR mRNA were detected in peripheral blood of control group, CK19 mRNA-positive rate was 48% and 80% in peripheral blood and tumor tissue from the experimental group, respectively, and EGFR mRNA-positive rate was 36% and 76%, respectively. Lymph node metastasis happened in the exponential growth phase and transfer rate was 60%(15/25). The expression of CK19 mRNA and EGFR mRNA in lymphatic metastasis groups was higher than that of control, with a positive correlation between lymphatic metastasis and CTC (r = 0.655 , P < 0.01). The protein positive expression rate of EGFR were 88%(22/25) in tumor tissue. All peripheral blood expressed EGFR concomitant EGFR expressing in tumor tissues, and a high expression of EGFR in tumor tissue displayed high expression of EGFR in peripheral blood as well. CONCLUSION The expression of CK19 and EGFR mRNA in the peripheral blood can provide predictive information of lymphatic metastasis, EGFR mRNA might be a new target of treatment and diagnosis for malignant tumour.
Animals ; Disease Models, Animal ; ErbB Receptors ; blood ; Keratin-19 ; blood ; Laryngeal Neoplasms ; blood ; pathology ; Lymphatic Metastasis ; Mice ; Mice, Nude ; Neoplasm Staging ; RNA, Messenger ; genetics