Yanqiu Zhang

Systemic Immune Effects of Titanium Dioxide Nanoparticles after Repeated Intratracheal Instillation in Rat

The potential immune effects of titanium dioxide nanoparticles (nano-TiO2) are raising concern. Our previous study verified that nano-TiO2 induce local immune response in lung tissue followed by intratracheal instillation administration. In this study, we aim to evaluate the systemic immune effects of nano-TiO2. Sprague Dawley rats were treated by intratracheal instillation with nano-TiO2 at doses of 0.5, 4, and 32 mg/kg body weight, micro-TiO2 with 32 mg/kg body weight and 0.9% NaCl, respectively. The exposure was conducted twice a week, for four consecutive weeks. Histopathological immune organs from exposed animals showed slight congestion in spleen, generally brown particulate deposition in cervical and axillary lymph node. Furthermore, immune function response was characterized by increased proliferation of T cells and B cells following mitogen stimulation and enhanced natural killer (NK) cell killing activity in spleen, accompanying by increased number of B cells in blood. No significant changes of Th1-type cytokines (IL-2 and INF-γ) and Th2-type cytokines (TNF-α and IL-6) were observed. Intratracheal exposure to nano-TiO2 may be one of triggers to be responsible for the systemic immune response. Further study is needed to confirm long-lasting lymphocyte responses and the potential mechanisms.

Integrated analysis of long non-coding RNA‑associatedceRNA network reveals potential lncRNA biomarkers in human lung adenocarcinoma

Accumulating evidence has highlighted the important roles of long non-coding RNAs (lncRNAs) acting as competing endogenous RNAs (ceRNAs) in tumor biology. However, the roles of cancer specific lncRNAs in lncRNA-related ceRNA network of lung adenocarcinoma (LUAD) are still unclear. In the present study, the 465 RNA sequencing profiles in LUAD patients were obtained from the cancer genome atlas (TCGA) database, which provides large sample RNA sequencing data free of charge, and 41 cancer specific lncRNAs, 25 miRNAs and 1053 mRNAs (fold change >2, p<0.05) were identified. Then, the lncRNA-miRNA-mRNA ceRNA network of LUAD was constructed with 29 key lncRNAs, 24 miRNAs and 72 mRNAs. Subsequently, we selected these 29 key lncRNAs to analyze their correlation with clinical features, and 21 of them were aberrantly expressed with tumor pathological stage, TNM staging system, lymph node metastasis and patient outcome assessment, respectively. Furthermore, there were 5 lncRNAs (BCRP3, LINC00472, CHIAP2, BMS1P20 and UNQ6494) positively correlated with overall survival (OS, log-rank p<0.05). Finally, 7 cancer specific lncRNAs were randomly selected to verify the expression in 53 newly diagnosed LUAD patients using qRT-PCR. The expression results between TCGA and qRT-PCR were 100% in agreement. The correlation between AFAP1-AS1 and LINC00472 and clinical features were also confirmed. Thus, our results showed the lncRNA expression profiles and we constructed an lncRNA-miRNA-mRNA ceRNA network in LUAD. The present study provides novel insight for better understanding of lncRNA-related ceRNA network in LUAD and facilitates the identification of potential biomarkers for diagnosis and prognosis.

Expression profiling and pathway analysis of microRNA expression in the lungs of mice exposed to long-term, low-dose benzo(a)pyrene

We investigated the effect of low-dose, long-term benzo(a)pyrene exposure on the miRNA expression profile in lung tissue of mice, and the potential mechanism of miRNAs in the benzo(a)pyreneinduced damage to health. Subject mice were treated with 5 μg/kg benzo(a)pyrene twice a week for 8 weeks by intragastrical administration, while control mice were treated with the same volume of olive oil solvent. All mice were then fed for another 8 weeks without exposure to benzo(a)pyrene, after which total RNA was isolated from lung tissue. miRNA expression profiles were generated by SOLiD™3 high-throughput sequencing and the signaling pathways represented were analyzed by DIANA-mirPath. A total of 74 miRNAs were dysregulated in mice lung tissues exposed to benzo(a)pyrene. Signaling pathways regulated by benzo(a)pyrene exposure included those involved in the environmental information process and human tumorigenesis. We conclude that low-dose, long-term benzo(a)pyrene exposure alters specific miRNA expression profiles.

In vivo evaluation of acute toxicity of water-soluble carbon nanotubes

Multi-walled carbon nanotubes (MWCNTs) were modified with three types of hydrophilic moieties: phosphatidylcholine (PC), polyethylene glycol (PEG), and PC-terminated polyethylene glycol (PEG–PC). Based on the high water dispersibility of modified carbon nanotubes (CNTs), the extremely high doses of these CNT derivatives were intravenously injected in rats from 12.5 to 200 mg kg−1. Based upon pathologic results, most of the injected CNT derivatives accumulated in the lung, whereas CNT–PC dispersed throughout the organism compared to CNT–PEG and CNT–PEG–PC, thereby resulting in a broader distribution in liver and spleen which may be biologically relevant. The modified CNT induced only low acute toxicity, which may contribute to biocompatibility of mammals to these grafted functional groups.

MicroRNA-125b may function as an oncogene in lung cancer cells

The present study aimed to investigate the biofunctions of microRNA (miR)‑125b on lung cancer cells. A miR genechip array was used to examine the differential expression of miRs between 95D lung cancer cells and 16 human bronchial epithelial (HBE) cells. Overexpression of miR‑125b was observed in the cell lines and in the lung carcinoma tissues compared with the adjacent tissues, confirmed using reverse transcription quantitative polymerase chain reaction. Bioinformatic analysis of miR‑125b was also performed, including target prediction, gene ontology and pathway analysis. MTT, flow cytometry and Transwell assays were also used to examine the effect of downregulated miR‑125b on the proliferation, apoptosis, invasive ability and cell cycle of 95D cells. Significant differences were observed in the expression of 45 miRs in the 95D cells compared with those in 16HBE cells and the expression of miR‑125b was significantly higher in 95D cells compared with that in 16HBE cells as well as in lung tumor tissues compared with that in adjacent tissues. In addition, inhibition of the expression of miR‑125b in 95D cells induced apoptosis, G1/S phase arrest and reduction of their invasive ability. In addition, bioinformatics software predicted that miR‑125b was involved in the regulation of several pathways associated with cancer, including the transforming growth factor‑β, Wnt and mitogen‑activated protein kinase signaling pathways. These data indicated for the first time, to the best of our knowledge, that miR‑125b may function as an oncogene in lung cancer.

Dysregulated lncRNA-UCA1 contributes to the progression of gastric cancer through regulation of the PI3K-Akt-mTOR signaling pathway

The long non-coding RNA (lncRNA) urothelial carcinoma-associated 1 (UCA1) has been recently shown to be dysregulated during disease occurrence and to play an important role in the progression of several cancers. However, the biological role and potential regulation mechanism of UCA1 in the carcinogenesis of gastric cancer remain unclear. In the present study, we found that UCA1 was aberrantly upregulated in gastric cancer tissues and gastric cancer cell lines, and was associated with TNM stage and metastasis. UCA1 silencing significantly inhibited gastric cancer BGC-823 cell proliferation and increased its apoptosis. We also found that UCA1 played an important role in the migration and invasion of gastric cancer cells in vitro and in vivo. The molecular mechanism of UCA1 suggested that UCA1 regulates the PI3K-Akt-mTOR signaling proteins and their downstream mediators, to alter gastric cancer progression in vitro and in vivo. Collectively, the results showed a pivotal role of UCA1 in the tumorigenesis of gastric cancer. In addition, the study characterized a novel lncRNA-mRNA regulatory network, which may lead to a better understanding of the pathogenesis of gastric cancer and assist in lncRNA-directed diagnosis and therapy for this malignancy.The long non-coding RNA (lncRNA) urothelial carcinoma-associated 1 (UCA1) has been recently shown to be dysregulated during disease occurrence and to play an important role in the progression of several cancers. However, the biological role and potential regulation mechanism of UCA1 in the carcinogenesis of gastric cancer remain unclear. In the present study, we found that UCA1 was aberrantly upregulated in gastric cancer tissues and gastric cancer cell lines, and was associated with TNM stage and metastasis. UCA1 silencing significantly inhibited gastric cancer BGC-823 cell proliferation and increased its apoptosis. We also found that UCA1 played an important role in the migration and invasion of gastric cancer cells in vitro and in vivo. The molecular mechanism of UCA1 suggested that UCA1 regulates the PI3K-Akt-mTOR signaling proteins and their downstream mediators, to alter gastric cancer progression in vitro and in vivo. Collectively, the results showed a pivotal role of UCA1 in the tumorigenesis of gastric cancer. In addition, the study characterized a novel lncRNA-mRNA regulatory network, which may lead to a better understanding of the pathogenesis of gastric cancer and assist in lncRNA-directed diagnosis and therapy for this malignancy.

Differential expression profiles of long non-coding RNAs reveal potential biomarkers for identification of human gastric cancer.

Gastric cancer (GC) is one of the most lethal malignancies worldwide. To reduce its high mortality, sensitive and specific biomarkers for early detection are urgently needed. Recent studies have reported that tumor-specific long non-coding RNAs (lncRNAs) seem to be potential biomarkers for the early diagnosis and treatment of cancer. In the present study, lncRNA and mRNA expression profiling of GC specimens and their paired adjacent non-cancerous tissues was performed. Differentially expressed lncRNAs and mRNAs were identified through microarray analysis. The function of differential mRNA was determined by gene ontology and pathway analysis and the functions of lncRNAs were studied by constructing a co-expression network to find the relationships with corresponding mRNAs. We connected the co-expression network, mRNA functions, and the results of the microarray profile differential expression and selected 14 significantly differentially expressed key lncRNAs and 21 key mRNAs. Quantitative RT-PCR (qRT-PCR) was conducted to verify these key RNAs in 50 newly diagnosed GC patients. The data showed that RP5-919F19, CTD-2541M15 and UCA1 was significantly higher expressed. AP000459, LOC101928316, RP11-167N4 and LINC01071 expression was significantly lower in 30 advanced GC tumor tissues than adjacent non-tumor tissues P<0.05. Then, we further validated the above significant differential expression candidate lncRNAs in 20 early stage GC patients. Results showed that CTD-2541M15 and UCA1 were significantly higher expressed, AP000459, LINC01071 and MEG3 expression was significantly lower in 20 early stage GC patient tumor tissues than adjacent non-tumor tissues (P<0.05). In addition, expression of these lncRNAs shows gradual upward trend from early stage GC to advanced GC. Furthermore, conditional logistic regression analysis revealed the aberrant expression of CTD-2541M15, UCA1 and MEG3 closely linked with GC. There is a set of differentially expressed lncRNAs in GC which may be associated with the progression and development of GC. The differential expression profiles of lncRNAs in GC may be promising biomarkers for the early detection and early screening of high‑risk populations.

Comprehensive analysis of aberrantly expressed microRNA profiles reveals potential biomarkers of human lung adenocarcinoma progression

Lung adenocarcinoma (LUAD) is a complex disease that poses challenges for diagnosis and treatment. The aim of the present study is to investigate LUAD-specific key microRNAs (miRNAs) from large-scale samples in The Cancer Genome Atlas (TCGA) database. We used an integrative computational method to identify LUAD-specific key miRNAs related to TNM stage and lymphatic metastasis from the TCGA database. Twenty-five LUAD-specific key miRNAs (fold change >2, p<0.05) from the TCGA database were investigated, and 15 were found to be aberrantly expressed with respect to clinical features. Three miRNAs were correlated with overall survival (log-rank p<0.05). Then, 5 miRNAs were randomly selected for verification of expression in 53 LUAD patient tissues using qRT-PCR. Diagnostic value of these above 5 miRNAs was determined by areas under receiver operating characteristic curves (ROC). Finally, the LUAD-related miRNA miR-30a-3p was selected for verification of biologic function in A549 cells. The results of tests for cell proliferation, apoptosis, and target genes suggested that miR-30a-3p decreases cell proliferation and promotes apoptosis through targeting AKT3. Therefore, miR-30a-3p may be a promising biomarker for the early screening of high-risk populations and early diagnosis of LUAD. Our studies provide insights into identifying novel potential biomarkers for diagnosis and prognosis of LUAD.