Comprehensive landscape of extracellular vesicle-derived RNAs in cancer initiation, progression, metastasis and cancer immunology.

Extracellular vesicles (EVs), a class of heterogeneous membrane vesicles, are generally divided into exosomes and microvesicles on basis of their origination from the endosomal membrane or the plasma membrane, respectively. EV-mediated bidirectional communication among various cell types supports cancer cell growth and metastasis. EVs derived from different cell types and status have been shown to have distinct RNA profiles, comprising messenger RNAs and non-coding RNAs (ncRNAs). Recently, ncRNAs have attracted great interests in the field of EV-RNA research, and growing numbers of ncRNAs ranging from microRNAs to long ncRNAs have been investigated to reveal their specific functions and underlying mechanisms in the tumor microenvironment and premetastatic niches. Emerging evidence has indicated that EV-RNAs are essential functional cargoes in modulating hallmarks of cancers and in reciprocal crosstalk within tumor cells and between tumor and stromal cells over short and long distance, thereby regulating the initiation, development and progression of cancers. In this review, we discuss current findings regarding EV biogenesis, release and interaction with target cells as well as EV-RNA sorting, and highlight biological roles and molecular mechanisms of EV-ncRNAs in cancer biology.

ARID5B gene polymorphisms and the risk of childhood acute lymphoblastic leukemia: a meta-analysis.

Genome-wide association studies have implicated several single-nucleotide polymorphisms (SNPs) in the AT-rich interactive domain 5B (ARID5B) gene in children with ALL; however, whether ARID5B variants (rs10821936, rs10994982, rs7089424) are associated with childhood ALL remains controversial. We performed this study to obtain more conclusive results. Eligible studies were searched in PubMed, Web of Science, and EMBASE. Odds ratios and 95% confidence intervals were calculated. A total of 26 studies were included. Analyses stratified by ethnicity revealed that three polymorphisms are significantly associated with the odds of childhood ALL in Caucasians, and rs10994982 and rs7089424 with the odds of childhood ALL in Asian populations. Furthermore, subtype analyses provided strong evidence that the three polymorphisms are highly associated with the risk of B-cell ALL. Our findings indicate that the ARID5B variants (rs10821936, rs10994982, rs7089424) are significantly associated with the risk of childhood ALL.

Catechol-O-methyltransferase 158G/A polymorphism and endometriosis/adenomyosis susceptibility: A meta-analysis in the Chinese population.

PURPOSE: An association between catechol-O-methyltransferase (COMT) 158G/A polymorphism and endometriosis/adenomyosis susceptibility has been reported in the previous studies, but the results were inconsistent. This study was conducted to explore this association in the Chinese population using meta-analysis. MATERIALS AND METHODS: PubMed, Springer Link, Ovid, Chinese Wanfang Data Knowledge Service Platform, Chinese National Knowledge Infrastructure, and Chinese Biology Medicine were searched for all relevant studies published up to December 2015. The odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to estimate the strength of the associations. RESULTS: A total of 7 case-control studies including 782 cases and 700 controls were included in this meta-analysis. Overall, COMT 158G/A polymorphism was found to be significantly associated with endometriosis and adenomyosis risk in the Chinese population (A vs. G, OR = 1.21, 95% CI: 1.02-1.42; AA vs. GG, OR = 1.47, 95% CI: 1.01-2.14; AA vs. GG + GA, OR = 1.42, 95% CI: 0.99-2.03; AA + GA vs. GG, OR = 1.20, 95% CI: 0.97-1.49). In subgroup analyses stratified by ethnicity, source of controls and disease groups, the significant risk was found in Chinese not mentioned the ethnicity, in population-based studies and adenomyosis. CONCLUSIONS: COMT 158G/A polymorphism may contribute to the risk of endometriosis and adenomyosis in Chinese, particularly for adenomyosis.

Transcriptional E2F1/2/5/8 as potential targets and transcriptional E2F3/6/7 as new biomarkers for the prognosis of human lung carcinoma.

E2F is a group of genes that encode a family of transcription factors (TFs) in higher eukaryotes and participate in cell cycle regulation and DNA synthesis in mammalian cells. Evidence from cell lines, mouse models, and human tissues indicates that TFs are implicated in lung cancer (LC) tumorigenesis. However, the diverse expression patterns and prognostic values of eight E2Fs have yet to be elucidated. In the current study, we examined the transcriptional and survival data of E2Fs in patients with LC from ONCOMINE, GEPIA, Kaplan-Meier Plotter, and cBioPortal databases. We found that the expression levels of E2F1/2/3/5/6/7/8 were higher in lung adenocarcinoma and squamous cell lung carcinoma tissues than in lung tissues, whereas the expression level of E2F4 was lower in the former than in the latter. The expression levels of E2F2/4/5/7/8 were correlated with advanced tumor stage. Survival analysis using the Kaplan-Meier Plotter database revealed that the high transcription levels of E2F1/2/4/5/7/8 were associated with low relapse-free survival (RFS) in all of the patients with LC. Conversely, high E2F3/6 levels predicted high RFS in these patients. This study implied that E2F3/6/7 are potential targets of precision therapy for patients with LC and that E2F1/2/4/5/8 are new biomarkers for the prognosis of LC.

Emerging landscape of circular RNAs in lung cancer.

Lung cancer, the leading cause of cancer deaths worldwide, is characterized with malignant cell growth. Advances in next-generation sequencing has helped us further understand RNA and identify novel circular RNAs (circRNAs) that may be useful in the early diagnosis and treatment of lung cancer. Similar to other noncoding RNAs, circRNAs present diverse biological functions in normal and disease states, including various types of cancers. This review focuses mainly on the poorly understood functions of circRNA in lung cancer. This paper also summarizes the recent advances in circRNA biogenesis, analyzes the role of circRNAs in cancers, and discusses the potential mechanisms of circRNAs in lung cancer.

Gestational age and childhood leukemia: A meta-analysis of epidemiologic studies.

OBJECTIVE: An increasing amount of evidence shows that childhood leukemia is initiated in utero. Birth characteristics initiated in utero, such as gestational age, may play a role in leukemogenesis. The purpose of our meta-analysis is to explore the association between gestational age and childhood leukemia. METHODS: Relevant studies up to 21 April 2017 were collected by searching PubMed and EMBASE databases. Subgroup analysis, sensitivity analysis and publication bias assessment were conducted. RESULTS: A total of 13 studies were included. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) for preterm birth and postterm birth were 1.06 (0.98, 1.13) and 1.01 (0.90, 1.13) for childhood leukemia, 1.04 (0.97, 1.11) and 1.03 (0.95, 1.12) for acute lymphocytic leukemia (ALL), 1.20 (1.00, 1.44) and 1.20 (1.00, 1.43) for acute myeloid leukemia (AML), compared with full-term birth. Study type and study region were the reasons behind the heterogeneity. In subgroup analyses, the summary ORs with 95% CI for childhood leukemia and ALL were 1.23 (1.07, 1.41) and 1.21 (1.06, 1.39) for postterm birth in cohort studies. No significant changes in sensitivity analyses and no publication bias were observed in our analysis. CONCLUSION: Our results suggest that both preterm and postterm infants have an elevated risk of developing AML. In addition, postterm birth increased the risk of childhood leukemia and ALL in cohort studies. However, more studies are warranted to validate these results and explore the biologic mechanisms underlying these relationships.

miR-206/133b Cluster: A Weapon against Lung Cancer?

Lung cancer is a deadly disease that ends numerous lives around the world. MicroRNAs (miRNAs) are a group of non-coding RNAs involved in a variety of biological processes, such as cell growth, organ development, and tumorigenesis. The miR-206/133b cluster is located on the human chromosome 6p12.2, which is essential for growth and rebuilding of skeletal muscle. The miR-206/133b cluster has been verified to be dysregulated and plays a crucial role in lung cancer. miR-206 and miR-133b participate in lung tumor cell apoptosis, proliferation, migration, invasion, angiogenesis, drug resistance, and cancer treatment. The mechanisms are sophisticated, involving various target genes and molecular pathways, such as MET, EGFR, and the STAT3/HIF-1α/VEGF signal pathway. Hence, in this review, we summarize the role and potential mechanisms of the miR-206/133b cluster in lung cancer.

Effect of Lycium bararum polysaccharides on methylmercury-induced abnormal differentiation of hippocampal stem cells.

The aim of the present study was to observe the effects of a general extract of Lycium bararum polysaccharides (LBPs) on methylmercury (MeHg)-induced damage in hippocampus neural stem cells (hNSCs). The hippocampal tissues of embryonic day 16 Sprague-Dawley rats were extracted for the isolation, purification and cloning of hNSCs. Following passage and proliferation for 10 days, the cells were allocated at random into the following groups: Control, LBPs, MeHg and MeHg + LBPs. MTT and microtubule-associated protein 2 (MAP-2)/glial fibrillary acidic protein/Hoechst immunofluorescence tests were performed to detect the differentiation and growth of hNSCs in the various groups. The differentiation rate of MeHg-treated hNSCs and the perimeter of MAP-2-positive neurons were 3.632±0.63% and 62.36±5.58 µm, respectively, significantly lower compared with the control group values of 6.500±0.81% and 166±8.16 µm (P<0.05). Furthermore, the differentiation rate and the perimeter of MAP-2-positive neurons in LBPs groups cells was 7.75±0.59% and 253.3±11.21 µm, respectively, significantly higher compared with the control group (P<0.05). The same parameters in the MeHg + LBPs group were 5.92±0.98% and 111.9±6.07 µm, respectively, significantly higher than the MeHg group (P<0.05). The astrocyte differentiation rates in the MeHg and MeHg + LBPs group were 41.19±2.14 and 34.58±1.70, respectively (P<0.05). These results suggest that LBPs may promote the generation and development of new neurons and inhibit the MeHg-induced abnormal differentiation of astrocytes. Thus, LBPs may be considered to be a potential new treatment for MeHg-induced neurotoxicity in hNSCs.

A Systematic Assessment of Blood Lead Level in Children and Associated Risk Factors in China.

In this study, we searched multiple databases for all relevant original articles (1996-2013). To investigate blood lead levels (BLL) and possible risk factors for lead exposure among children in China A total of 388 articles met our inclusion criteria. The overall geometric mean (GM) BLL was 71 µg/L, and the prevalence of elevated BLL (EBLL, defined as BLL ⋝ 100 µg/L) was 18.48% among children. The prevalence of EBLL remained significantly higher among boys. In children less than 6 years of age, there were significantly increasing trends in both BLL and prevalence of EBLL in an age-dependent manner. The ban on leaded gasoline significantly reduced the BLL as well as EBLL prevalence; however, children whose parents had lower educational levels or were exposed to lead in the workplace had a higher EBLL prevalence. Despite its decline over time, the average BLL among children in China remains higher than the average level most recently reported in the United States. Childhood lead poisoning remains a public health problem in China.

Inhibition of DNA-dependent protein kinase catalytic subunit by small molecule inhibitor NU7026 sensitizes human leukemic K562 cells to benzene metabolite-induced apoptosis.

Benzene is an established leukotoxin and leukemogen in humans. We have previously reported that exposure of workers to benzene and to benzene metabolite hydroquinone in cultured cells induced DNA-dependent protein kinase catalytic subunit (DNA-PKcs) to mediate the cellular response to DNA double strand break (DSB) caused by DNA-damaging metabolites. In this study, we used a new, small molecule, a selective inhibitor of DNA-PKcs, 2-(morpholin-4-yl)-benzo[h]chomen-4-one (NU7026), as a probe to analyze the molecular events and pathways in hydroquinone-induced DNA DSB repair and apoptosis. Inhibition of DNA-PKcs by NU7026 markedly potentiated the apoptotic and growth inhibitory effects of hydroquinone in proerythroid leukemic K562 cells in a dose-dependent manner. Treatment with NU7026 did not alter the production of reactive oxygen species and oxidative stress by hydroquinone but repressed the protein level of DNA-PKcs and blocked the induction of the kinase mRNA and protein expression by hydroquinone. Moreover, hydroquinone increased the phosphorylation of Akt to activate Akt, whereas co-treatment with NU7026 prevented the activation of Akt by hydroquinone. Lastly, hydroquinone and NU7026 exhibited synergistic effects on promoting apoptosis by increasing the protein levels of pro-apoptotic proteins Bax and caspase-3 but decreasing the protein expression of anti-apoptotic protein Bcl-2. Taken together, the findings reveal a central role of DNA-PKcs in hydroquinone-induced hematotoxicity in which it coordinates DNA DSB repair, cell cycle progression, and apoptosis to regulate the response to hydroquinone-induced DNA damage.

Activation of Akt/GSK3ß and Akt/Bcl-2 signaling pathways in nickel-transformed BEAS-2B cells.

The Akt signaling pathway has been implicated in a wide range of cellular functions involving cell survival and proliferation, angiogenesis, metabolism and cell migration. Accumulating evidence suggests that Akt perturbations play an important role in human malignancy. Here, we investigated Akt perturbation in nickel-transformed cells. Chronic treatment of human bronchial epithelial BEAS-2B cells with low doses of nickel chloride resulted in cell transformation demonstrated by anchorage-independent (AI) growth, increased cell growth and alterations of cell growth pattern. Western blot assays show that phosphorylation of Akt at Ser473, but not that of p38, JNK and ERK, was increased in nickel-transformed cells compared with controls. Inhibition of Akt or PI3K by pharmacological or biochemical interference suppressed nickel AI growth and cell growth of transformed cells. Activation of Akt led to inhibition of GSK3ß by phosphorylation at Ser9 in nickel-transformed cells. In addition, two major anti-apoptotic proteins of the Bcl family, Bcl-2 and Bcl-XL, were increased in nickel-transformed cells. By employing the small interfering RNA technique (siRNA), our results showed that siRNA Akt attenuated the expression of Bcl-2 and Bcl-XL in nickel-transformed cells, indicating that induction of Bcl-2 and Bcl-XL was likely mediated through Akt. ROS generation was decreased in nickel-transformed cells compared with controls. Moreover, down-regulation of retinoblastoma protein (Rb) was observed in nickel-transformed cells. Taken together, these findings demonstrate that activation of Akt, followed by GSK3ß inhibition and Bcl-2, Bcl-XL up-regulation and decrease of ROS generation, along with a synergistic effect of Rb down-regulation may cause apoptosis resistance, contributing to the overall mechanism of nickel carcinogenesis.

Significant positive correlation of plasma BPDE-albumin adducts to urinary 1-hydroxypyrene in coke oven workers.

OBJECTIVE: To investigate the application of BPDE-albumin adducts as monitoring biomarkers for coke oven workers exposed to polycyclic aromatic hydrocarbons (PAHs) and to explore possible relationship between BPDE-albumin adducts and urinary 1-hydroxypyrene (1-OHP) levels in them. METHODS: Thirty-seven coke oven workers from a coke plant and 47 controls without the occupational exposure to PAHs were recruited in this study. The levels of plasma BPDE-albumin adducts and urinary 1-OHP were analyzed using high performance liquid chromatography. RESULTS: The median levels of BPDE-albumin adducts (42.10 fmol/mg albumin) and urinary 1-OHP (5.46 micromol/mol creatinine) were significantly higher in coke oven workers than in controls (14.16 fmol/mg albumin, 2.96 micromol/mol creatinine, respectively; P<0.01). Multiple logistic regression analysis showed that coke oven workers were at higher risk of having BPDE-albumin adduct levels above 25.30 micromol/mg albumin (OR=1.79, P<0.01) and urinary 1-OHP levels above 4.13 micromol/mol creatinine (OR=2.45, P<0.05). There was a positive correlation between the levels of BPDE-albumin adducts and urinary 1-OHP in all subjects (rs=0.349, P<0.01). CONCLUSION: BPDE-albumin adduct is a useful biomarker for monitoring long-term exposure to PAHs, and plasma BPDE-albumin adducts level is significantly correlated to urinary 1-OHP levels in coke oven workers.

[Effect of TTRAP expression on apoptosis induced by hydroquinone in HL-60 cells in vitro.].

OBJECTIVE: To study the effect of TTRAP expression on apoptosis induced by hydroquinone in HL-60 cells in vitro, and explore the relationship between TTRAP expression and the apoptosis. METHODS: Apoptotic and necrotic rate was examined by flow cytometer with Anti-AnnexinV/FITC Plus PI staining. The mRNA expression of TTRAP was detected by RT-PCR. The differences in different treated groups were compared. RESULTS: After different concentrations of hydroquinone to the cells for 0, 4, 8, 12 h culture, were added, the cell apoptotic rate in different concentrations of hydroquinone groups was significantly higher than that in blank control groups. The optimal concentration of hydroquinone was 200 micromol/L, lasting for 8 h. When it was 250 micromol/L, the necrotic rate increased significantly. The apoptosis induced by hydroquinone was associated with the culture time at the concentration of 200 micromol/L, and the peak apoptotic time was 8 h. Then the apoptotic rate decreased and necrotic rate increased. Furthermore, with the concentrations of hydroquinone increased and time lasted for 8 h, the apoptotic rate of cells increased, the amount of TTRAP expression in the mRNA level also increased accordingly. When the concentrations of hydroquinone was above 250 micromol/L, necrotic rate increased sharply, and the amount of TTRAP expression decreased. CONCLUSION: Hydroquinone could induce apoptosis of HL-60 cells. The up-regulation of TTRAP expression may promote hydroquinone to induce HL-60 cells to go into apoptosis in vitro with dose-effect and time-effect relationship.

[Protective effect of tert-butylhydroquinone on bone marrow cells in rats from cytotoxicity induced by benzene in vitro].

OBJECTIVE: To investigate the protective effect of tert-butylhydroquinone on bone marrow cells in rats from cytotoxicity induced by benzene in vitro. METHODS: The bone marrow cells in rats were divided into two groups randomizedly. Cells of the control group were stimulated by 0, 5, 10, 15, 20 mmol/L benzene for 2, 4, 6 hours respectively. Cells of the tBHQ-pretreated group were treated by 100 micromol/L tBHQ for 12 hours followed by the same conditions as the control group. The DNA damage was detected by single cell gel electrophoresis assay (SCGE) and cell apoptosis was examined by flow cytometry. The activities of NAD (P) H: quinone oxidoreductase (NQO1) in bone marrow cells of rats were also measured before benzene treatment in two groups. RESULTS: In control group, the DNA damage and the apoptosis of bone marrow cells was increased with the growing concentration and time of benzene treatment. The DNA migration and the lengths of DNA migration of the bone marrow cells in the rats under 5, 10, 15, 20 mmol/L benzene treatment in the tBHQ-pretreated group were significantly lower than those in control group at the same time point (P < 0.05). The apoptosis of the bone marrow cells in the rats stimulated by 15, 20 mmol/L benzene for 2 hours and 10, 15, 20 mmol/L benzene for 4 hours as well as 5, 10, 15, 20 mmol/L benzene for 6 hours were also significantly lower than those in control group (P < 0.05). The activities of NQO1 in the bone marrow cells in the rats were increased after tBHQ treatment (P < 0.01) (1.62 +/- 0.16 min(-1).mg(-1) vs. the control group: 0.95 +/- 0.08 min(-1).mg(-1)). CONCLUSION: The benzene can induce the DNA damage and the apoptosis of bone marrow cells in rats in a time dependent and dose dependent manner to some extent. The tBHQ can protect the bone marrow cells in rats from the cytotoxicity induced by benzene, which can be partly explained by the increase of the NQO1 activity induced by tBHQ.

[Detection of apoptosis genes differentially expressed in patients with different degrees of benzene poisoning by cDNA microarray].

OBJECTIVE: To investigate the differential expression of apoptosis genes in patients with different degrees of benzene poisoning by cDNA microarray. METHODS: Peripheral mononuclear cells were isolated from seven patients with benzene poisoning of different degrees (suspected 1 case, moderate 2, severe 2), and seven age and sex matched normal control subjects. Total RNA was extracted and purified, followed by reverse transcription to cDNAs with concomitant incorporation of fluorescent dCTP (Cy3 or Cy5). Then 177 genes associated with cell apoptosis were hybridized against the cDNAs probes in microarray. Fluorescent signals were scanned to detect apoptosis genes differentially expressed in patients and normal subjects. RESULTS: Forty one genes were found to be differentially expressed between benzene-poisoned patients and normal controls; among the 41 genes, three were up-regulated among patients with mild to moderate degrees of benzene poisoning and one up-regulated among all patients. The total amount of differentially expressed genes of apoptosis decreased with the aggravation of benzene poisoning. CONCLUSIONS: Differential expression of apoptosis genes was found in patients with benzene poisoning, suggesting a role of altered apoptosis in benzene-induced hematotoxicity.

[cDNA microarray to identify the significance of DNA replication and damage repair genes associated with benzene poisoning].

OBJECTIVE: To screen DNA replication, and damage repair genes associated with benzene poisoning by using gene expression profile analysis. METHODS: Leucocytes in peripheral blood of seven patients and seven normal controls were collected and total RNA was extracted. The cDNA probes were prepared by labeling cell RNA with Cy3-dUTP and Cy5-dUTP with reverse transcription. The arrays with 141 genes were hybridized against the cDNA probe mixture, and the fluorescent signals were scanned. RESULTS: Twenty five differentially expressed genes were screened out. Among these genes, 16 genes were up-regulated and 9 down-regulated. They were DNA replication genes such as PRIM2A, ORC1L etc; DNA synthesis, recombination and repair genes such as POLK etc; DNA damage signaling/repair proteins and DNA ligases such as RECQL, PRKDC, G22P1, ERCC3, ERCC1, CRY1, CHES1, BRCA2, APEX etc; proteins involved in recombination such as RECQL; and other DNA synthesis, recombination, and repair proteins such as SKIV2L, RBMS1, SON, SET. CONCLUSIONS: Some DNA replication, and damage repair genes associated with benzene poisoning show differential expression, which provides the basis for screening biomarkers of benzene poisoning.

[Analysis on tumor related gene expression profiles in benzene poisoning using cDNA microarray].

OBJECTIVE: To detect target genes for further study by way of analyzing the gene expression profiles of benzene poisoning by using cDNA microarray. METHODS: Peripheral mononuclear cells were isolated from seven patients with benzene poisoning of different degrees, and sevene age-and sex-matched normal subjects. Total RNA was extracted and purified, followed by revese transcription to cDNAs with concomitant incorporation of fluorescent dCTP (Cy3 or Cy5). The cDNAs were used as probes in microarray of 2780 cloned cDNA. Fluorescent signals were scanned to detect genes differentially expressed in patients and normal subjects. RESULTS: Among 7 pieces of cDNA microarray of 2780 tumour related genes, the expression of 16 genes, such as GRO1, TGFBR3, LYN ctc was upregulated, whereas the expression of 28 genes, such as FOSB, DJ-1, MCT-1 etc was down-regulated. CONCLUSION: Abnormal expression of tumour related genes of patients exposed to benzene suggests that they may be the key genes, which play important role in benzene-induced leucocythemia. cDNA microarray technique is useful to indicate the expression mode of benzene poisoning tumour related genes, and to find rapidly and effectively new research object and the way of gene therapy.