Yi Ba

Characterization of microRNAs in serum: a novel class of biomarkers for diagnosis of cancer and other diseases

Dysregulated expression of microRNAs (miRNAs) in various tissues has been associated with a variety of diseases, including cancers. Here we demonstrate that miRNAs are present in the serum and plasma of humans and other animals such as mice, rats, bovine fetuses, calves, and horses. The levels of miRNAs in serum are stable, reproducible, and consistent among individuals of the same species. Employing Solexa, we sequenced all serum miRNAs of healthy Chinese subjects and found over 100 and 91 serum miRNAs in male and female subjects, respectively. We also identified specific expression patterns of serum miRNAs for lung cancer, colorectal cancer, and diabetes, providing evidence that serum miRNAs contain fingerprints for various diseases. Two non-small cell lung cancer-specific serum miRNAs obtained by Solexa were further validated in an independent trial of 75 healthy donors and 152 cancer patients, using quantitative reverse transcription polymerase chain reaction assays. Through these analyses, we conclude that serum miRNAs can serve as potential biomarkers for the detection of various cancers and other diseases.

Secreted Monocytic miR-150 Enhances Targeted Endothelial Cell Migration

MicroRNAs (miRNAs) are a class of noncoding RNAs that regulate target gene expression at the posttranscriptional level. Here, we report that secreted miRNAs can serve as signaling molecules mediating intercellular communication. In human blood cells and cultured THP-1 cells, miR-150 was selectively packaged into microvesicles (MVs) and actively secreted. THP-1-derived MVs can enter and deliver miR-150 into human HMEC-1 cells, and elevated exogenous miR-150 effectively reduced c-Myb expression and enhanced cell migration in HMEC-1 cells. In vivo studies confirmed that intravenous injection of THP-1 MVs significantly increased the level of miR-150 in mouse blood vessels. MVs isolated from the plasma of patients with atherosclerosis contained higher levels of miR-150, and they more effectively promoted HMEC-1 cell migration than MVs from healthy donors. These results demonstrate that cells can secrete miRNAs and deliver them into recipient cells where the exogenous miRNAs can regulate target gene expression and recipient cell function.

Exogenous plant MIR168a specifically targets mammalian LDLRAP1: evidence of cross-kingdom regulation by microRNA

Our previous studies have demonstrated that stable microRNAs (miRNAs) in mammalian serum and plasma are actively secreted from tissues and cells and can serve as a novel class of biomarkers for diseases, and act as signaling molecules in intercellular communication. Here, we report the surprising finding that exogenous plant miRNAs are present in the sera and tissues of various animals and that these exogenous plant miRNAs are primarily acquired orally, through food intake. MIR168a is abundant in rice and is one of the most highly enriched exogenous plant miRNAs in the sera of Chinese subjects. Functional studies in vitro and in vivo demonstrated that MIR168a could bind to the human/mouse low-density lipoprotein receptor adapter protein 1 (LDLRAP1) mRNA, inhibit LDLRAP1 expression in liver, and consequently decrease LDL removal from mouse plasma. These findings demonstrate that exogenous plant miRNAs in food can regulate the expression of target genes in mammals.

Serum MicroRNA Expression Profile as a Biomarker in the Diagnosis and Prognosis of Pancreatic Cancer

BACKGROUND Detection of pancreatic cancer (PaC), particularly at early stages, remains a great challenge owing to lack of specific biomarkers. We sought to identify a PaC-specific serum microRNA (miRNA) expression profile and test its specificity and sensitivity as a biomarker in the diagnosis and prognosis of PaC. METHODS We obtained serum samples from 197 PaC cases and 158 age- and sex-matched cancer-free controls. We screened the differentially expressed serum miRNAs with Illumina sequencing by synthesis technology using pooled serum samples followed by RT-qPCR validation of a large number of samples arranged in multiple stages. We used risk score analysis to evaluate the diagnostic value of the serum miRNA profiling system. To assess the serum miRNA-based biomarker accuracy in predicting PaC, we performed additional double-blind testing in 77 PaC cases and 52 controls and diagnostic classification in 55 cases with clinically suspected PaC. RESULTS After the selection and validation process, 7 miRNAs displayed significantly different expression levels in PaC compared with controls. This 7 miRNA-based biomarker had high sensitivity and specificity for distinguishing various stages of PaC from cancer-free controls and also accurately discriminated PaC patients from chronic pancreatitis (CP) patients. Among the 7 miRNAs, miR-21 levels in serum were significantly associated with overall PaC survival. The diagnostic accuracy rate of the 7-miRNA profile was 83.6% in correctly classifying 55 cases with clinically suspected PaC. CONCLUSIONS These data demonstrate that the 7 miRNA-based biomarker can serve as a novel noninvasive approach for PaC diagnosis and prognosis.

Identification of ten serum microRNAs from a genome-wide serum microRNA expression profile as novel noninvasive biomarkers for nonsmall cell lung cancer diagnosis.

The detection of nonsmall cell lung cancer (NSCLC) at an early stage presents a daunting challenge due to the lack of a specific noninvasive marker. The discovery of microRNAs (miRNAs), particularly those found in serum, has opened a new avenue for tumor diagnosis. To determine whether the expression profile of serum miRNAs can serve as a NSCLC fingerprint, we performed Taqman probe‐based quantitative RT‐PCR assay to selected differentially expressed serum miRNAs from a sample set including 400 NSCLC cases and 220 controls, and risk score analysis to evaluate the diagnostic value of the serum miRNA profiling system. After a two‐phase selection and validation process, 10 miRNAs were found to have significantly different expression levels in NSCLC serum samples compared with the control serum samples. Risk score analysis showed that this panel of miRNAs was able to distinguish NSCLC cases from controls with high sensitivity and specificity. Under ROC curves, the AUC for tumor identification in training set and validation set were 0.966 and 0.972, respectively. Furthermore, the expression profile of the 10‐serum miRNAs was correlated with the stage of NSCLC patients, especially in younger patients and patients with current smoking habits. More importantly, the serum miRNA‐based biomarker for early NSCLC detection was supported by a retrospective analysis in which the 10‐serum miRNA profile could accurately classify serum samples collected up to 33 months ahead of the clinical NSCLC diagnosis. Taken together, we demonstrate that the profiling of 10‐serum miRNAs provides a novel noninvasive biomarker for NSCLC diagnosis.

Randomized, Double-Blind, Placebo-Controlled Phase III Trial of Apatinib in Patients With Chemotherapy-Refractory Advanced or Metastatic Adenocarcinoma of the Stomach or Gastroesophageal Junction

PURPOSE There is currently no standard treatment strategy for patients with advanced metastatic gastric cancer experiencing progression after two or more lines of chemotherapy. We assessed the efficacy and safety of apatinib, a novel vascular endothelial growth factor receptor 2 tyrosine kinase inhibitor, in patients with advanced gastric or gastroesophageal junction adenocarcinoma for whom at least two lines of prior chemotherapy had failed. PATIENTS AND METHODS This was a randomized, double-blind, placebo-controlled phase III trial. Patients from 32 centers in China with advanced gastric or gastroesophageal junction adenocarcinoma, for whom two or more prior lines of chemotherapy had failed, were enrolled. Patients were randomly assigned to oral apatinib 850 mg or placebo once daily. The primary end points were overall (OS) and progression-free survival (PFS). RESULTS Between January 2011 and November 2012, 267 patients were enrolled. Median OS was significantly improved in the apatinib group compared with the placebo group (6.5 months; 95% CI, 4.8 to 7.6 v 4.7 months; 95% CI, 3.6 to 5.4; P = .0149; hazard ratio, 0.709; 95% CI, 0.537 to 0.937; P = .0156). Similarly, apatinib significantly prolonged median PFS compared with placebo (2.6 months; 95% CI, 2.0 to 2.9 v 1.8 months; 95% CI, 1.4 to 1.9; P < .001; hazard ratio, 0.444; 95% CI, 0.331 to 0.595; P < .001). The most common grade 3 to 4 nonhematologic adverse events were hand-foot syndrome, proteinuria, and hypertension. CONCLUSION These data show that apatinib treatment significantly improved OS and PFS with an acceptable safety profile in patients with advanced gastric cancer refractory to two or more lines of prior chemotherapy.

Efficacy and safety of bevacizumab plus chemotherapy in Chinese patients with metastatic colorectal cancer: a randomized phase III ARTIST trial

The efficacy and safety of bevacizumab with modified irinotecan, leucovorin bolus, and 5-fluorouracil intravenous infusion (mIFL) in the first-line treatment of metastatic colorectal cancer (mCRC) has not been well evaluated in randomized clinical trials in Chinese patients. We conducted a phrase III trial in which patients with previously untreated mCRC were randomized 2:1 to the mIFL [irinotecan (125 mg/m2), leucovorin (20 mg/m2) bolus, and 5-fluorouracil intravenous infusion (500 mg/m2) weekly for four weeks every six weeks] plus bevacizumab (5 mg/kg every two weeks) group and the mIFL group, respectively. Co-primary objectives were progression-free survival (PFS) and 6-month PFS rate. In total, 214 patients were enrolled. Our results showed that addition of bevacizumab to mIFL significantly improved median PFS (4.2 months in the mIFL group vs. 8.3 months in the bevacizumab plus mIFL group, P < 0.001), 6-month PFS rate (25.0% vs. 62.6%, P < 0.001), median overall survival (13.4 months vs. 18.7 months, P = 0.014), and response rate (17% vs. 35%, P = 0.013). Grades 3 and 4 adverse events included diarrhea (21% in the mIFL group and 26% in the bevacizumab plus mIFL group) and neutropenia (19% in the mIFL group and 33% in the bevacizumab plus mIFL group). No wound-healing complications or congestive heart failure occurred. Our results suggested that bevacizumab plus mIFL is effective and well tolerated as first-line treatment for Chinese patients with mCRC. Clinical benefit and safety profiles were consistent with those observed in pivotal phase III trials with mainly Caucasian patients.

PGC-1α induces apoptosis in human epithelial ovarian cancer cells through a PPARγ-dependent pathway

Peroxisome proliferator-activated receptor gamma (PPARγ) coactivator-1 alpha (PGC-1α) coactivates multiple transcription factors and regulates several metabolic processes. The current study investigated the role of PGC-1α in the induction of apoptosis in human epithelial ovarian cancer cells. The PGC-1α mRNA level between human ovaries and human ovarian epithelial tumors was examined by quantitative RT-PCR. Less PGC-1α expression was found in the surface epithelium of malignant tumors compared with normal ovaries. Overexpression of PGC-1α in human epithelial ovarian cancer cell line Ho-8910 induced cell apoptosis through the coordinated regulation of Bcl-2 and Bax expression. Microarray analyses confirmed that PGC-1α dramatically affected the apoptosis-related genes in Ho-8910 cells. Mitochondrial functional assay showed that the induction of apoptosis was through the terminal stage by the release of cytochrome c. Furthermore, PGC-1α-induced apoptosis was partially, but not completely, blocked by PPARγ antagonist (GW9662), and suppression of PPARγ expression by siRNA also inhibited PGC-1α-induced apoptosis in Ho-8910 cells. These data suggested that PGC-1α exerted its effect through a PPARγ-dependent pathway. Our findings indicated that PGC-1α was involved in the apoptotic signal transduction pathways and downregulation of PGC-1α may be a key point in promoting epithelial ovarian cancer growth and progression.

The pretreatment platelet and plasma fibrinogen level correlate with tumor progression and metastasis in patients with pancreatic cancer

Abstract Cancer patients frequently present with activated coagulation pathways and thrombocytosis, which are potentially associated with tumor progression and prognosis. However, the prognostic value of abnormal plasma fibrinogen and platelet levels for the treatment of pancreatic cancer is unclear. The purpose of our study was to evaluate the prognostic value of plasma fibrinogen and platelet levels in pancreatic cancer, and to devise a prognostic model to identify the patients with greatest risk for a poor overall survival. One hundred and twenty-five patients diagnosed with pancreatic ductal adenocarcinoma in our hospital between May 2000 and June 2005 were included in this study. The plasma fibrinogen and platelet levels were examined before treatment and analyzed along with patient clinicopathological parameters and overall survival. The foundation of prognostic model was based on the risk factors according to the Cox proportional hazard model. The incidence of hyperfibrinogenemia and thrombocytosis was 24.8% (31/125) and 15.2% (19/125), respectively. The mean fibrinogen concentration differed significantly between the early (I/II) and late (III/IV) stage patients (3.19 ± 0.70 vs. 3.65 ± 0.90 g/l, p = 0.008). Patients with a higher concentration of plasma fibrinogen and platelets had a worse prognosis (p < 0.05). There also existed a significant correlation between higher fibrinogen/platelet levels and distant organ metastasis (p < 0.05, respectively). Bivariate correlation analysis showed that plasma fibrinogen levels correlated significantly with platelet levels (p = 0.000). Multivariate analysis revealed that pretreatment plasma fibrinogen levels (p = 0.027), tumor stage (p = 0.026) and distant metastasis (p = 0.027) were independent prognostic factors. The median survival time for the low-, intermediate-, and high-risk groups was 9.6 months (95% CI 6.2–13.0), 3.8 months (95% CI 2.3–5.3), and 2.3 months (95% CI 0.9–3.7), respectively (p = 0.000). Pretreatment plasma fibrinogen and platelet levels closely correlated with tumor progression, metastasis and overall survival in pancreatic cancer. The foundation of prognostic model may help us identify the greatest risk populations with pancreatic cancer.

MiRNA27a is a biomarker for predicting chemosensitivity and prognosis in metastatic or recurrent gastric cancer

We previously identified five miRNAs (miR‐1, miR‐20a, miR‐27a, miR‐34a, and miR‐423‐5p) that are up‐regulated in gastric cancer. The goal of this study was to investigate the value of these miRNAs as potential biomarkers for predicting chemosensitivity and prognosis in metastatic or recurrent gastric cancer patients who received first‐line chemotherapy. A total of 82 patients with metastatic or recurrent GC receiving first‐line chemotherapy were included in our study. The expression levels of the five miRNAs were evaluated using hydrolysis probe‐based stem‐loop quantitative reverse transcription polymerase chain reaction (qRT‐PCR) in individual samples before first‐line chemotherapy. Patients receiving first‐line chemotherapy with fluoropyrimidine combined with oxaliplatin or paclitaxel were chosen for the chemosensitivity analysis. The relationships between expression of the five‐miRNAs and clinicopathological parameters, response to chemotherapy and prognosis were analyzed statistically. Patients with higher miRNA1 expression levels tended to have a higher rate of liver metastasis, and higher miRNA34a expression levels occurred more frequently in males (P = 0.022). The expression of the remaining three miRNAs showed no obvious relationship to any of the clinicopathological features. The partial response rates of the patients with high miRNA1 expression and low miRNA1 expression were 11.1% and 23.1%, respectively (P = 0.048). Similar results were observed for miRNA27a (the partial response rate was 7.7% vs. 25.9%, P = 0.018). Patients with up‐regulated miRNA27a expression had a significantly worse overall survival (OS) than patients with lower miRNA27a expression (P = 0.024). In patients with MRGC, miRNA27a is a potential biomarker for predicting resistance to fluoropyrimidine‐based chemotherapy and a novel prognostic marker for gastric cancer. J. Cell. Biochem. 115: 549–556, 2014.