Yong Chen

Lung cancer is the leading cause of cancer death in the world, and aberrant expression of miRNA is a common feature during the cancer initiation and development. Our previous study showed that levels of miRNA-148a assessed by quantitative real-time polymerase chain reaction (qRT-PCR) were a good prognosis factor for non-small cell lung cancer (NSCLC) patients. In this study, we used high-throughput formalin-fixed and paraffin-embedded (FFPE) lung cancer tissue arrays and in situ hybridization (ISH) to determine the clinical significances of miRNA-148a and aimed to find novel target of miRNA-148a in lung cancer. Our results showed that there were 86 of 159 patients with low miRNA-148a expression and miRNA-148a was significantly down-regulated in primary cancer tissues when compared with their adjacent normal lung tissues. Low expression of miRNA-148a was strongly associated with high tumor grade, lymph node (LN) metastasis and a higher risk of tumor-related death in NSCLC. Lentivirus mediated overexpression of miRNA-148a inhibited migration and invasion of A549 and H1299 lung cancer cells. Furthermore, we validated Wnt1 as a direct target of miRNA-148a. Our data showed that the Wnt1 expression was negatively correlated with the expression of miRNA-148a in both primary cancer tissues and their corresponding adjacent normal lung tissues. In addition, overexpression of miRNA-148a inhibited Wnt1 protein expression in cancer cells. And knocking down of Wnt-1 by siRNA had the similar effect of miRNA-148a overexpression on cell migration and invasion in lung cancer cells. In conclusion, our results suggest that miRNA-148a inhibited cell migration and invasion through targeting Wnt1 and this might provide a new insight into the molecular mechanisms of lung cancer metastasis.

// Xin Guo 1, 2, 3 , Xiaohui Lv 4 , Xing Lv 2 , Yueyun Ma 5 , Lin Chen 1, * and Yong Chen 2, * 1 Department of General Surgery, Chinese PLA General Hospital, Beijing, P.R. China 2 Department of Hepatobiliary Surgery, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi, P.R. China 3 Department of Endoscopic Surgery, Chinese PLA 451st Hospital, Xi’an, Shaanxi, P.R. China 4 Department of Gynecology and Obstetrics, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi, P.R. China 5 Department of Clinical Laboratory Medicine, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi, P.R. China * Authors share co-senior authorship Correspondence to: Yong Chen, email: yongchen62@yahoo.com Lin Chen, email: chenlinbj@sina.com Keywords: miR-21, AFP, hepatocellular carcinoma, ROC, biomarker Received: December 19, 2016      Accepted: March 21, 2017      Published: April 19, 2017 ABSTRACT Serum miRNAs have gained great popularity to act as circulating biomarkers of several cancers. In this study, we aimed to evaluate the diagnostic efficiency of serum miR-21 as novel biomarkers for patients with hepatocellular carcinoma (HCC) and other controls. A total of 533 individuals were recruited and conducted in a two-step analysis. The pilot group included 40 HCC patients and 40 healthy donors. The expression levels of miR-21 were significantly higher in primary HCC tissues than in adjacent noncancerous tissues (P<0.0001). HCC patients exhibited significantly higher serum levels of miR-21 than HD (P<0.0001). In the verification group, the mean serum levels of miR-21 in 175 patients with HCC were significantly higher than in 64 with CHB, 78 with LC and 136 HD (all P<0.0001). ROC curves demonstrated that the AUC of miR-21 was 0.849, sensitivity 82.1% and specificity 83.9%. Furthermore, serum miR-21 maintained its diagnostic efficiency in AFP-negative HCC subgroups with AUC 0.831, sensitivity 81.2% and specificity 83.2%. The serum levels of miR-21 could distinguish HCC from CHB and LC (AUC 0.789, sensitivity 76.9%, specificity 85.7% and AUC 0.814, sensitivity 80.8%, specificity 72.9%, respectively). In addition, the serum levels of miR-21 were significantly associated with clinical stage (P=0.006) and distant metastasis (P=0.000). Thus, our findings suggest that miR-21 together with AFP may help enhance the diagnosis of HCC, especially of AFP-negative HCC, and could distinguish HCC from CHB and LC.

COVID-19 is mainly associated with respiratory distress syndrome, but a subset of patients often present gastrointestinal (GI) symptoms. Imbalances of gut microbiota have been previously linked to respiratory virus infection. Understanding how the gut–lung axis affects the progression of COVID-19 can provide a novel framework for therapies and management. In this study, we examined the gut microbiota of patients with COVID-19 ( n = 47) and compared it to healthy controls ( n = 19). Using shotgun metagenomic sequencing, we have identified four microorganisms unique in COVID-19 patients, namely Streptococcus thermophilus , Bacteroides oleiciplenus , Fusobacterium ulcerans , and Prevotella bivia . The abundances of Bacteroides stercoris , B. vulgatus , B. massiliensis , Bifidobacterium longum , Streptococcus thermophilus , Lachnospiraceae bacterium 5163FAA, Prevotella bivia , Erysipelotrichaceae bacterium 6145, and Erysipelotrichaceae bacterium 2244A were enriched in COVID-19 patients, whereas the abundances of Clostridium nexile , Streptococcus salivarius , Coprococcus catus , Eubacterium hallii , Enterobacter aerogenes , and Adlercreutzia equolifaciens were decreased ( p < 0.05). The relative abundance of butyrate-producing Roseburia inulinivorans is evidently depleted in COVID-19 patients, while the relative abundances of Paraprevotella sp. and the probiotic Streptococcus thermophilus were increased. We further identified 30 KEGG orthology (KO) modules overrepresented, with 7 increasing and 23 decreasing modules. Notably, 15 optimal microbial markers were identified using the random forest model to have strong diagnostic potential in distinguishing COVID-19. Based on Spearman’s correlation, eight species were associated with eight clinical indices. Moreover, the increased abundance of Bacteroidetes and decreased abundance of Firmicutes were also found across clinical types of COVID-19. Our findings suggest that the alterations of gut microbiota in patients with COVID-19 may influence disease severity. Our COVID-19 classifier, which was cross-regionally verified, provides a proof of concept that a set of microbial species markers can distinguish the presence of COVID-19.

ARF6 GTPase is a conserved regulator of membrane trafficking and actin-based cytoskeleton dynamics at the leading edge of migrating cells. A key determinant of ARF6 function is the lifetime of the GTP-bound active state, which is orchestrated by GTPase-activating protein (GAP) and GTP-GDP exchanging factor. However, very little is known about the molecular mechanisms underlying ARF6-mediated cell migration. To systematically analyze proteins that regulate ARF6 activity during cell migration, we performed a proteomic analysis of proteins selectively bound to active ARF6 using mass spectrometry and identified a novel ARF6-specific GAP, ACAP4. ACAP4 encodes 903 amino acids and contains two coiled coils, one pleckstrin homology domain, one GAP motif, and two ankyrin repeats. Our biochemical characterization demonstrated that ACAP4 has a phosphatidylinositol 4,5-bisphosphate-dependent GAP activity specific for ARF6. The co-localization of ACAP4 with ARF6 occurred in ruffling membranes formed upon AIF(4) and epidermal growth factor stimulation. ACAP4 overexpression limited the recruitment of ARF6 to the membrane ruffles in the absence of epidermal growth factor stimulation. Expression of GTP hydrolysis-resistant ARF6(Q67L) resulted in accumulations of ACAP4 and ARF6 in the cytoplasmic membrane, suggesting that GTP hydrolysis is required for the ARF6-dependent membrane remodeling. Significantly the depletion of ACAP4 by small interfering RNA or inhibition of ARF6 GTP hydrolysis by overexpressing GAP-deficient ACAP4 suppressed ARF6-dependent cell migration in wound healing, demonstrating the importance of ACAP4 in cell migration. Thus, our study sheds new light on the biological function of ARF6-mediated cell migration.

MicroRNA (miR)-486-5p expression is often reduced in human cancers. However, its expression in gastric carcinoma and its relation to clinicopathological features and prognosis are unclear. Tissue microarrays were constructed from 84 patients with gastric adenocarcinoma (GC) who were undergoing radical resection. miR-486-5p expression was detected by miRNA-locked nucleic acid in situ hybridization, and its correlations with clinicopathological features and overall survival were analyzed. Bioinformatic studies predict that fibroblast growth factor 9 (FGF9) is a potential target gene of miR-486-5p. miR-486-5p was mainly located in the cytoplasm of GC cells and neighboring normal tissues. Compared with paracancerous normal tissue, miR-486-5p expression was decreased in 63.1% (53/84) of the GC samples, increased in 32.1% (27/84) and unchanged in 4.8% (4/84). FGF9 expression was decreased in 69.0% (58/84) of GC samples and increased in 31.0% (26/84) compared with normal paracancerous tissues using immunohistochemical analysis. Low or unchanged miR-486-5p expression (P = 0.002), tumor stage (P = 0.001), tumor status (P = 0.001), node status (P = 0.001), tumor size (P = 0.004), and depth of tumor invasion (P = 0.013) were significant negative prognostic predictors for overall survival in patients with GC. After stratification according to American Joint Committee on Cancer (AJCC) stage, low/unchanged miR-486-5p expression remained a significant predictor of poor survival in stage II (P = 0.024) and stage III (P = 0.003). Cox regression analysis identified the following predictors of poor prognosis: tumor status (hazard ratio [HR], 7.19; 95% confidence interval [CI], 1.75-29.6; P = 0.006), stage (HR, 2.62; 95%CI, 1.50-4.59; P = 0.001), lymph node metastasis (HR, 2.52; 95% CI, 1.27-4.99; P = 0.008), low/unchanged miR-486-5p (HR, 2.47; 95% CI, 1.35-4.52; P = 0.003), high level of FGF9 (HR, 2.41; 95% CI, 1.42-4.09; P = 0.001) and tumor size (HR, 2.50; 95% CI, 1.30-4.82; P = 0.006). Low or unchanged expression of miR-486-5p compared with neighboring normal tissues was associated with a poor prognosis, while high expression was associated with a good prognosis in GC. miR-486-5p may thus be useful for evaluating prognosis and may provide a novel target treatment in patients with GC.