Lihong Yin

The Cluster of miR-143 and miR-145 Affects the Risk for Esophageal Squamous Cell Carcinoma through Co-Regulating Fascin Homolog 1

MicroRNAs (miRNAs), 18–24 nt non-coding RNAs, are thought to play important roles in cell proliferation, differentiation, apoptosis, and development. Recent studies suggest that some of the known microRNAs map to a single genomic locale within a single polycistronic transcript. But the roles of the cluster remain to be known. In order to understand the role and mechanism of a cluster of miR-143 and miR-145 in esophageal squamous cell carcinoma (ESCC), the association of mature miR-143 and miR-145 expression with the risk for esophageal cancer was evaluated in ESCC patients with a case-control study, and target protein regulated by mature miRNA was analyzed in ESCC cell lines with 3′UTR luciferase reporter assay. The expression levels of miR-143 and miR-145 were determined in 110 pairs of esophageal cancer tissues and adjacent normal tissues using real-time reverse transcription PCR. The relative expression of miR-143 and miR-145 were statistically different between cancer tissues and matched controls. The combined expression of miR-143 and miR-145 was significantly associated with the risk for esophageal cancer. Meanwhile, the reduced expression of two miRNAs in tumor patient was supposed to have a trend of lymph node metastases. The co-expression pattern of miR-143 and miR-145 was analyzed with Pearson correlation. It showed a significant correlation between these two miRNAs expression both in tissues and tumor cell lines. 3′UTR luciferase reporter assay indicated that Fascin Homolog 1 (FSCN1) could be co-regulated by miR-143 and miR-145. The protein level of FSCN1 showed no significant linear correlation with miR-143 and miR-145 expression in ESCC cell lines with Western blotting analysis. In conclusion, since miR-143 and miR-145 could regulate oncogenic FSCN1 and take part in the modulation of metastases, the result suggested the combination variable of miR-143 and miR-145 as a potential biomarker for earlier diagnosis and prognosis of esophageal cancer.

Differential expression profiles of microRNAs as potential biomarkers for the early diagnosis of esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is one of the most lethal malignancies worldwide. To reduce the high morbidity and mortality of the disease, sensitive and specific biomarkers for early detection are urgently needed. Tumor-specific microRNAs (miRNAs) seem to be potential biomarkers for the early diagnosis and treatment of cancer. In this study, differentially expressed miRNAs in tumor tissues and adjacent non-tumor tissues were detected by miRNA microarrays. Stem-loop real-time reverse transcription PCR was conducted to verify the candidate miRNAs discovered by microarray analysis. The data showed that hsa-miR-338-3p, hsa-miR‑218 and hsa-miR-139-5p were downregulated in tumor tissues compared with adjacent non-tumor tissues, while hsa-miR‑183, hsa-miR-574-5p, hsa-miR-21* and hsa-miR‑601 were upregulated in tumor tissues. Multiple regression analysis revealed the aberrant expression of hsa-miR-338-3p, hsa‑miR-139-5p, hsa-miR‑574-5p and hsa-miR-601 increased the risk of esophageal cancer. Furthermore, we found hsa-miR-21* was significantly increased in heavy drinking patients. Therefore, there is a set of differentially expressed miRNAs in esophageal cancer which may be associated with the incidence and development of ESCC. Differential expression profiles of miRNAs in ESCC may be promising biomarkers for the early screening of high-risk populations and early detection.

Influence of Different Sizes of Titanium Dioxide Nanoparticles on Hepatic and Renal Functions in Rats with Correlation to Oxidative Stress

As titanium dioxide (TiO2) nanoparticles are widely used commercially, the potential effects of TiO2 nanoparticles on humans are a concern. To evaluate the effects of TiO2 nanoparticles on hepatic and renal functions and correlate changes to oxidative stress, Sprague-Dawley rats were treated with TiO2 particles of two different specific surface areas (TiO2-S50: 50 m2/g, and TiO2-S210: 210 m2/g) at 0.5, 5, or 50 mg/kg body weight by intratracheal instillation. After 7 d, TiO2 nanoparticles produced no obvious acute toxicity on hepatic and renal functions. However, superoxide dismutase (SOD) activity of plasma and glutathione peroxidase (GSH-PX) activity of kidney in the low-dose TiO2-S210 group were significantly decreased. After TiO2-S210 exposure, malondialdehyde (MDA) levels of liver and kidney in intermediate and high-dose groups were significantly increased. This change only appeared in liver after TiO2-S50 exposure. Furthermore, SOD activity in liver and kidney and GSH-PX activity in kidney with low TiO2-S210 exposure group were significantly less than with low TiO2-S50. No apparent pathological changes in liver and kidney were observed. Intratracheal exposure to TiO2 nanoparticles may induce oxidative stress in liver and kidney, but does not influence hepatic or renal functions. There was no apparent evidence that TiO2-S210 was more toxic than TiO2-S50. In general, intratracheal exposure to TiO2 did not markedly affect extrapulmonary tissue functions.

Circulating miR-155 Expression in Plasma: A Potential Biomarker for Early Diagnosis of Esophageal Cancer in Humans

MicroRNAs (miRNAs) are postulated to play important roles in oncogenesis. Recently, extracellular miRNAs were detected in plasma or serum of diseased subjects. However, the role of circulating miRNAs in plasma/serum remains to be elucidated. In this study, the relative expressions of miR-155, miR-183, and miR-20a in esophageal tissue were found to be significantly associated with increased risk for esophageal cancer. The relative expressions of circulating miR-155 and miR-183 were significantly reduced in cancer patients. Circulating miR-155 showed significantly higher risk for esophageal cancer when adjusted by smoking status and alcohol use. Circulating miR-155 was found to have significant diagnostic value for esophageal cancer as evidenced by a receiver operating characteristic curve area of 66%. However, Pearson analysis showed no statistical correlation in the relative miRNAs expression between plasma and esophageal tissues, which suggested different origins of circulating miRNAs distinct from tumor cell miRNAs. In conclusion, results suggest that circulating miR-155 in plasma may serve as a reliable, novel, noninvasive biomarker for early diagnosis and detection of esophageal cancer.

Tumor-Suppressive Function of miR-139-5p in Esophageal Squamous Cell Carcinoma

Recent studies have demonstrated the possible function of miR-139-5p in tumorigenesis. However, the exact mechanism of miR-139-5p in cancer remains unclear. In this study, the association of miR-139-5p expression with esophageal squamous cell carcinoma (ESCC) was evaluated in 106 pairs of esophageal cancer and adjacent non-cancerous tissue from ESCC patients. The tumor suppressive features of miR-139-5p were measured by evaluating cell proliferation and cell cycle state, migratory activity and invasion capability, as well as apoptosis. Luciferase reporter assay and Western blot analysis were performed to determine the target gene regulated by miR-139-5p. The mRNA level of NR5A2, the target gene of miR-139-5p, was determined in ESCC patients. Results showed that reduced miR-139-5p level was associated with lymph node metastases of ESCC. MiR-139-5p was investigated to induce cell cycle arrest in the G0/G1 phase and to suppress the invasive capability of esophageal carcinoma cells by targeting the 3′UTR of oncogenic NR5A2. Cyclin E1 and MMP9 were confirmed to participate in cell cycle arrest and invasive suppression induced by NR5A2, respectively. Pearson correlation analysis further confirmed the significantly negative correlation between miR-139-5p and NR5A2 expression. The results suggest that miR-139-5p exerts a growth- and invasiveness-suppressing function in human ESCCs, which demonstrates that miR-139-5p is a potential biomarker for early diagnosis and prognosis and is a therapeutic target for ESCC.

Exosome-shuttling microRNA-21 promotes cell migration and invasion-targeting PDCD4 in esophageal cancer

Recent evidence indicates that exosomes can mediate certain microRNAs (miRNAs) involved in a series of biological functions in tumor occurrence and development. Our previous studies showed that microRNA-21 (miR-21) was abundant in both esophageal cancer cells and their corresponding exosomes. The present study explored the function of exosome-shuttling miR-21 involved in esophageal cancer progression. We found that exosomes could be internalized from the extracellular space to the cytoplasm. The exosome-derived Cy3-labeled miR-21 mimics could be transported into recipient cells in a neutral sphingomyelinase 2 (nSMase2)-dependent manner. miR-21 overexpression from donor cells significantly promoted the migration and invasion of recipient cells by targeting programmed cell death 4 (PDCD4) and activating its downstream c-Jun N-terminal kinase (JNK) signaling pathway after co-cultivation. Our population plasma sample analysis indicated that miR-21 was upregulated significantly in plasma from esophageal cancer patients and showed a significant risk association for esophageal cancer. Our data demonstrated that a close correlation existed between exosome-shuttling miR-21 and esophageal cancer recurrence and distant metastasis. Thus, exosome-shuttling miR-21 may become a potential biomarker for prognosis among esophageal cancer patients.

Evaluation of pesticide toxicities with differing mechanisms using Caenorhabditis elegans.

The aim of this study was to (1) determine whether model organism Caenorhabditis elegans was sensitive to pesticides at the maximum concentration limits regulated by national agency standards, and (2) examine the multi-biological toxicities occurring as a result of exposure to pesticides. Five pesticides, namely, chlorpyrifos, imibacloprid, buprofezin, cyhalothrin, and glyphosate, with four different mechanisms of action were selected for the investigation. In accordance with national agency requirements, 4 exposed groups were used for each tested pesticide with the concentration scales ranging from 1.0 × 10−3 to 1 mg/L. L4 larvae were exposed for 24 and 72 h, respectively. Endpoints of locomotion, propagation, and development were selected for the assay as parameters of toxicity. After exposure for 24 h, both the body bend frequency and head thrash frequency of nematodes exposed to chlorpyrifos, imibacloprid, and cyhalothrin decreased in a concentration-dependent manner, and there were significant differences between exposed groups at maximum concentration level (MCL) compared to control. The generation time of nematodes exposed to buprofezin 24 h significantly increased in a concentration-dependent manner in the highest exposed group. When exposed for 72 h, the body bend frequency and head thrash frequency of nematodes exposed to cyhalothrin markedly decreased at MCL. The generation time and brood size of nematodes exposed to buprofezin were reduced in a concentration-dependent manner. The behavior of nematodes was sensitive to pesticides with neurotoxic properties, while pesticides affecting insect growth modified the reproductive system. The effects of pesticides on nematodes exposed for 24 h appeared more sensitive than with exposure for 72 h. Caenorhabditis elegans may thus be used for assessing the adverse effects of pesticide residues in aquatic environment.

Effects of subchronic exposure to multi-walled carbon nanotubes on mice.

Carbon nanotubes have attracted attention not only due to electrical, optical, and mechanical applications but also due to their presence in biological and pharmaceutical products. In this study, modified multi-walled carbon nanotubes (MWCNT) were used as a model to evaluate potential subchronic effects of carbon nanotubes on mice. ICR mice were treated with phosphorylcholine-grafted multi-walled carbon nanotubes (MWCNT-PC) daily for 28 d at 10, 50, or 250 mg/kg by the intraperitoneal (ip) route. Subchronic exposure to MWCNT-PC did not produce any apparent systemic effects in mice. The body weight of the high-dose group was significantly lower than control in male mice, whereas tissue to body weight ratios of liver, spleen, and lung rose significantly with increase of dose of MWCNT-PC. There were significant differences between high-dose exposure and control groups. Accumulation of carbon nanotubes and inflammation response in liver, spleen, and lung were observed in the high-dose exposure group. No systemic toxicity and histopathological changes were found in 10-mg/kg exposure groups. Data in the present study support the view that MWCNT in vivo do not exert apparent marked effects in mice and that MWCNT products are relatively safe for human consumption.

Identification of Plasma Metabolomic Profiling for Diagnosis of Esophageal Squamous-Cell Carcinoma Using an UPLC/TOF/MS Platform

Epidemiological studies indicated that esophageal squamous-cell carcinoma (ESCC) is still one of the most common causes of cancer incidence in the world. Searching for valuable markers including circulating endogenous metabolites associated with the risk of esophageal cancer, is extremely important A comparative metabolomics study was performed by using ultraperformance liquid chromatography-electrospray ionization-accurate mass time-of-flight mass spectrometry to analyze 53 pairs of plasma samples from ESCC patients and healthy controls recruited in Huaian, China. The result identified a metabolomic profiling of plasma including 25 upregulated metabolites and five downregulated metabolites, for early diagnosis of ESCC. With a database-based verification protocol, 11 molecules were identified, and six upregulated molecules of interest in ESCC were found to belong to phospholipids as follows: phosphatidylserine, phosphatidic acid, phosphatidyl choline, phosphatidylinositol, phosphatidyl ethanolamine, and sphinganine 1-phosphate. Clinical estimation of metabolic biomarkers through hierarchical cluster analysis in plasma samples from 17 ESCC patients and 29 healthy volunteers indicated that the present metabolite profile could distinguish ESCC patients from healthy individuals. The cluster of aberrant expression of these metabolites in ESCC indicates the critical role of phospholipid metabolism in the oncogenesis of ESCC and suggests its potential ability to assess the risk of ESCC development in addition to currently used risk factors.

Expression profiling of exosomal miRNAs derived from human esophageal cancer cells by Solexa high-throughput sequencing.

Cellular genetic materials, such as microRNAs (miRNAs), mRNAs and proteins, are packaged inside exosomes, small membrane vesicles of endocytic origin that are released into the extracellular environment. These cellular genetic materials can be delivered into recipient cells, where they exert their respective biological effects. However, the miRNA profiles and biological functions of exosomes secreted by cancer cells remain unknown. The present study explored the miRNA expression profile and distribution characteristics of exosomes derived from human esophageal cancer cells through Solexa high-throughput sequencing. Results showed that 56,421 (2.94%) unique sequences in cells and 7727 (0.63%) in exosomes matched known miRNAs. A total of 342 and 48 known miRNAs were identified in cells and exosomes, respectively. Moreover, 64 and 32 novel miRNAs were predicted in cells and exosomes, respectively. Significant differences in miRNA expression profiles were found between human esophageal cancer cells and exosomes. These findings provided new insights into the characteristics of miRNAs in exosomes derived from human esophageal cancer cells and the specific roles of miRNAs in intercellular communication mediated by exosomes in esophageal cancer.