Long-Term Cigarette Smoke Exposure and Changes in MiRNA Expression and Proteome in Non-Small-Cell Lung Cancer

Clinical significance of miR-9-5p in NSCLC and its relationship with smoking

Purpose

Dysregulated expression of microRNA (miRNAs) in lung cancer has been wildly reported. The clinicopathologic significance of miR-9-5p in non-small-cell lung cancer (NSCLC) patients and its effect on NSCLC progression were explored in this study.

Patients and methods

A total of 76 NSCLC patients were included. miR-9-5p expression was evaluated by real-time quantitative polymerase chain reaction (RT-qPCR). Then, in vitro experiments including cell growth curve assays, colony formation assays, and transwell migration assays were performed. Further clinicopathological and prognostic values were explored using bioinformatics analysis of the TCGA database.

Results

miR-9-5p expression was significantly increased in tumor tissues (both P < 0.0001). miR-9-5p expression was relatively higher in larger tumors (P = 0.0327) and in lung squamous carcinoma (LUSC) (P = 0. 0143). In addition, miR-9-5p was significantly upregulated in the normal lung tissues of cigarette smokers (P = 0.0099). In vitro, miR-9-5p was correlated with cell proliferation and migration. After that, bioinformatics analysis of the TCGA database indicated that miR-9-5p was correlated with tumor size (P = 0.0022), lymphatic metastasis (P = 0.0141), LUSC (P < 0.0001), and smoking history (P < 0.0001). Finally, a prognostic study indicated high miR-9-5p expression was correlated with poor prognosis in LUAD (P = 0.0121).

Conclusion

Upregulation of miR-9-5p may have an oncogenic effect in NSCLC and may be related to smoking. The conclusion of this study may help find new prognostic and therapeutic targets for NSCLC and the exploration of the relationship between smoking and lung cancer.

Long term exposure of cigarette smoke condensate (CSC) mediates transcriptomic changes in normal human lung epithelial Beas-2b cells and protection by garlic compounds

Chronic cigarette smoke condensate (CSC) exposure is one of the preventable risk factors in the CS-induced lung cancer. However, understanding the mechanism of cellular transformation induced by CS in the lung remains limited. We investigated the effect of long term exposure of CSC in human normal lung epithelial Beas-2b cells, and chemopreventive mechanism of organosulphur garlic compounds, diallyl sulphide (DAS) and diallyl disulphide (DADS) using Next Generation Sequencing (NGS) transcriptomic analysis. CSC regulated 1077 genes and of these 36 genes are modulated by DAS while 101 genes by DADS. DAS modulated genes like IL1RL1 (interleukin-1 receptor like-1), HSPA-6 (heat shock protein family A, member 6) while DADS demonstrating ADTRP (Androgen-Dependent TFPI Regulating Protein), ANGPT4 (Angiopoietin 4), GFI1 (Growth Factor-Independent 1 Transcriptional Repressor), TBX2 (T-Box Transcription Factor 2), with some common genes like NEURL-1 (Neuralized E3-Ubiquitin Protein Ligase 1), suggesting differential effects between these two garlic compounds. They regulate genes by influencing pathways including HIF-1alpha, STAT-3 and matrix metalloproteases, contributing to the chemoprotective ability of organosulfur garlic compounds against CSC-induced cellular transformation. Taken together, we demonstrated CSC induced global gene expression changes pertaining to cellular transformation which potentially can be delayed with dietary chemopreventive phytochemicals like DS and DADS influencing alterations at the transcriptomic level.

The Impact of Tobacco Cigarettes, Vaping Products and Tobacco Heating Products on Oxidative Stress

Cells constantly produce oxidizing species because of their metabolic activity, which is counteracted by the continuous production of antioxidant species to maintain the homeostasis of the redox balance. A deviation from the metabolic steady state leads to a condition of oxidative stress. The source of oxidative species can be endogenous or exogenous. A major exogenous source of these species is tobacco smoking. Oxidative damage can be induced in cells by chemical species contained in smoke through the generation of pro-inflammatory compounds and the modulation of intracellular pro-inflammatory pathways, resulting in a pathological condition. Cessation of smoking reduces the morbidity and mortality associated with cigarette use. Next-generation products (NGPs), as alternatives to combustible cigarettes, such as electronic cigarettes (e-cig) and tobacco heating products (THPs), have been proposed as a harm reduction strategy to reduce the deleterious impacts of cigarette smoking. In this review, we examine the impact of tobacco smoke and MRPs on oxidative stress in different pathologies, including respiratory and cardiovascular diseases and tumors. The impact of tobacco cigarette smoke on oxidative stress signaling in human health is well established, whereas the safety profile of MRPs seems to be higher than tobacco cigarettes, but further, well-conceived, studies are needed to better understand the oxidative effects of these products with long-term exposure.

Application of two-dimensional difference gel electrophoresis to identify protein changes between center, margin, and adjacent non-tumor tissues obtained from non-small-cell lung cancer with adenocarcinoma or squamous cell carcinoma subtype

Lung cancer is responsible for the most cancer-related mortality worldwide and the mechanism of its development is poorly understood. Proteomics has become a powerful tool offering vital knowledge related to cancer development. Using a two-dimensional difference gel electrophoresis (2D-DIGE) approach, we sought to compare tissue samples from non-small-cell lung cancer (NSCLC) patients taken from the tumor center and tumor margin. Two subtypes of NSCLC, adenocarcinoma (ADC) and squamous cell carcinoma (SCC) were compared. Data are available via ProteomeXchange with identifier PXD032736 and PXD032962 for ADC and SCC, respectively. For ADC proteins, 26 significant canonical pathways were identified, including Rho signaling pathways, a semaphorin neuronal repulsive signaling pathway, and epithelial adherens junction signaling. For SCC proteins, nine significant canonical pathways were identified, including hypoxia-inducible factor-1α signaling, thyroid hormone biosynthesis, and phagosome maturation. Proteins differentiating the tumor center and tumor margin were linked to cancer invasion and progression, including cell migration, adhesion and invasion, cytoskeletal structure, protein folding, anaerobic metabolism, tumor angiogenesis, EMC transition, epithelial adherens junctions, and inflammatory responses. In conclusion, we identified several proteins that are important for the better characterization of tumor development and molecular specificity of both lung cancer subtypes. We also identified proteins that may be important as biomarkers and/or targets for anticancer therapy.

Recent advancements and application of in vitro models for predicting inhalation toxicity in humans

Animals have been indispensable in testing chemicals that can pose a risk to human health, including those delivered by inhalation. In recent years, the combination of societal debate on the use of animals in research and testing, the drive to continually enhance testing methodologies, and technology advancements have prompted a range of initiatives to develop non-animal alternative approaches for toxicity testing. In this review, we discuss emerging in vitro techniques being developed for the testing of inhaled compounds. Advanced tissue models that are able to recreate the human response to toxic exposures alongside examples of their ability to complement in vivo techniques are described. Furthermore, technology being developed that can provide multi-organ toxicity assessments are discussed.

Faecal miRNA profiles associated with age, sex, BMI, and lifestyle habits in healthy individuals

For their stability and detectability faecal microRNAs represent promising molecules with potential clinical interest as non-invasive diagnostic and prognostic biomarkers. However, there is no evidence on how stool miRNA profiles change according to an individual’s age, sex, and body mass index (BMI) or how lifestyle habits influence the expression levels of these molecules. We explored the relationship between the stool miRNA levels and common traits (sex, age, BMI, and menopausal status) or lifestyle habits (physical activity, smoking status, coffee, and alcohol consumption) as derived by a self-reported questionnaire, using small RNA-sequencing data of samples from 335 healthy subjects. We detected 151 differentially expressed miRNAs associated with one variable and 52 associated with at least two. Differences in miR-638 levels were associated with age, sex, BMI, and smoking status. The highest number of differentially expressed miRNAs was associated with BMI (n = 92) and smoking status (n = 84), with several miRNAs shared between them. Functional enrichment analyses revealed the involvement of the miRNA target genes in pathways coherent with the analysed variables. Our findings suggest that miRNA profiles in stool may reflect common traits and lifestyle habits and should be considered in relation to disease and association studies based on faecal miRNA expression.

MicroRNA Interactome Multiomics Characterization for Cancer Research and Personalized Medicine: An Expert Review

MicroRNAs (miRNAs) that are mutually modulated by their interacting partners (interactome) are being increasingly noted for their significant role in pathogenesis and treatment of various human cancers. Recently, miRNA interactome dissected with multiomics approaches has been the subject of focus since individual tools or methods failed to provide the necessary comprehensive clues on the complete interactome. Even though single-omics technologies such as proteomics can uncover part of the interactome, the biological and clinical understanding still remain incomplete. In this study, we present an expert review of studies involving multiomics approaches to identification of miRNA interactome and its application in mechanistic characterization, classification, and therapeutic target identification in a variety of cancers, and with a focus on proteomics. We also discuss individual or multiple miRNA-based interactome identification in various pathological conditions of relevance to clinical medicine. Various new single-omics methods that can be integrated into multiomics cancer research and the computational approaches to analyze and predict miRNA interactome are also highlighted in this review. In all, we contextulize the power of multiomics approaches and the importance of the miRNA interactome to achieve the vision and practice of predictive, preventive, and personalized medicine in cancer research and clinical oncology.

The Role of MicroRNAs in Lung Cancer: Implications for Diagnosis and Therapy

Lung cancer is the first cause of cancer death in the world due to its high prevalence, aggressiveness, late diagnosis, lack of effective treatment and poor prognosis. It also shows high rate of recurrence, metastasis and drug resistance. All these problems highlight the urgent needs for developing new strategies using noninvasive biomarkers for early detection, metastasis and recurrence of disease. MicroRNAs (miRNAs) are a class of small noncoding RNAs that regulate gene expression post-transcriptionally. These molecules found to be abnormally expressed in increasing number of human disease conditions including cancer. miRNAs could be detected in body fluids such as blood, serum, urine and sputum, which leads us towards the idea of using them as non-invasive biomarker for cancer detection and monitoring cancer treatment and recurrence. miRNAs are found to be deregulated in lung cancer initiation and progression and could regulate lung cancer cell proliferation and invasion. In this review, we summarized recent progress and discoveries in microRNAs regulatory role in lung cancer initiation and progression. In addition, the role of microRNAs in EGFR signaling pathway regulation is discussed briefly.

Long-term exposure to cigarette smoke influences characteristics in human gingival fibroblasts

BACKGROUND

Periodontal disease is a chronic inflammatory disease caused by periodontopathic bacteria accumulated in the gingival sulcus and periodontal pocket. Cigarette smoking is a well-established risk factor for periodontal disease, and periodontal tissues in smokers are chronically exposed to cigarette smoke on a long-term basis.

OBJECTIVE

In this study, we investigated the effects of long-term exposure to nicotine or cigarette smoke condensate (CSC) on cellular functions of human gingival fibroblasts (HGFs).

METHODS

In vitro-maintained HGFs were divided into two groups. The HGFs of the short-term and the long-term culture groups were cultured for 4 and 25 days, respectively, in the presence or absence of nicotine, which is one of the main components of cigarette smoke, or CSC. The cellular proliferation and migration capacities of HGFs exposed to nicotine or CSC were evaluated by WST-1 and wound healing assays. The effects of exposure to nicotine or CSC on the expression of various extracellular matrix (ECM) components, inflammatory cytokines, and senescence-related genes were examined by real-time polymerase chain reaction and enzyme-linked immunosorbent assay. The cellular senescence of HGFs exposed to nicotine or CSC was detected by the senescence-associated β-galactosidase (SA-β-gal) assay. To explore the senescence-associated microRNA (miRNA), we extracted miRNA from the HGFs and the expression profiles were examined by miRNA array.

RESULTS

In short-term culture, no significant changes were observed. Long-term exposure of HGFs to nicotine or CSC significantly suppressed their cellular proliferation and migration and upregulated type Ⅰ collagen, type Ⅲ collagen, interleukin (IL)-6, IL-8, p16, p21, and p53 mRNA expression, and IL-6 and IL-8 protein expression. Furthermore, long-term nicotine or CSC exposure significantly increased the percentage of SA-β-gal-positive HGFs. In addition, long-term nicotine or CSC exposure reduced miR-29b and miR-199a expression to less than 50% of that in the unstimulated HGFs.

CONCLUSION

These data suggest that long-term smoking habits may reduce wound healing ability, modulate ECM protein homeostasis, stimulate the inflammatory response, and accelerate cellular senescence in HGFs, and consequently accelerate the progression of periodontal diseases.

Polymorphic variants INSIG2 rs6726538, HLA-DRB1 rs9272143, and GCNT1P5 rs7780883 contribute to the susceptibility of cervical cancer in the Bangladeshi women

Objective

Cervical cancer is a gynecological health problem, affecting nearly 500,000 women each year worldwide. Genome‐wide association studies have revealed multiple susceptible genes and their polymorphisms for cervical carcinoma risk. We have carried out this case‐control study to investigate the association of INSIG2 rs6726538 (A; T), HLA‐DRB1 rs9272143 (T; C), and GCNT1P5 rs7780883 (G; A) with cervical cancer.

Methods

The present study recruited 234 cervical cancer patients as cases and 212 healthy females as controls. We have applied the tetra‐primer amplification refractory mutation system polymerase chain reaction (T‐ARMS‐PCR) method for genotyping.

Results

The SNP rs6726538 was significantly associated with increased risk of cervical cancer in all genetic models (AT vs. AA: OR = 3.30, 95% CI = 2.19–4.97, p < 0.0001; TT vs. AA: OR = 8.72, 95% CI = 3.87–19.7, p < 0.0001; AT+TT vs. AA: OR = 3.87, 95% CI = 2.61–5.73, p < 0.0001; T vs. A: OR = 2.97, 95% CI = 2.20–4.01, p < 0.0001) except the recessive model which showed a significantly reduced risk (TT vs. AA+AT: OR = 0.20, 95% CI = 0.09–0.44, p = 0.0001). rs9272143 showed significantly reduced risk for the additive model 1, dominant model, and allelic model (TC vs. TT: OR = 0.46, 95% CI = 0.31–0.70, p = 0.0004; TC+CC vs. TT: OR = 0.47 95% CI = 0.32–0.70, p = 0.0002; C vs. T: OR = 0.56, 95% CI = 0.40–0.78, p = 0.0006, respectively). The third variant, rs7780883, was significantly associated with increased risk in additive model 2, dominant, and allelic models (AA vs. GG: OR = 5.08, 95% CI = 2.45–10.5, p < 0.0001; GA+AA vs. GG: OR = 1.54, 95% CI = 1.06–2.24, p = 0.0237; A vs. G: OR = 1.88, 95% CI = 1.34–2.52, p < 0.0001, consecutively), whereas recessive model reduced the risk of cervical cancer (AA vs. GG+GA: OR = 0.20, 95% CI = 0.09–0.41, p < 0.0001). Other models of these SNPs were not associated with cervical cancer. All significant associations for three SNPs withstand after Bonferroni correction except the additive model 2 of rs7780883.

Conclusion

Our study concludes that INSIG2 rs6726538, HLA‐DRB1 rs9272143, and GCNT1P5 rs7780883 polymorphisms may contribute to the development of cervical cancer in the Bangladeshi population.

Acid ceramidase, a double-edged sword in cancer aggression: A minireview

Acid ceramidase (AC), the key enzyme of the ceramide metabolic pathway hydrolyzes pro-apoptotic ceramide to sphingosine, which by the action of sphingosine-1-kinase is metabolized to mitogenic sphingosine-1-phosphate. The intracellular level of AC determines ceramide/sphingosine-1-phosphate rheostat which in turn decides the cell fate. The upregulated AC expression during cancerous condition acts as a "double-edged sword" by converting pro-apoptotic ceramide to anti-apoptotic sphingosine-1-phosphate, wherein on one end, the level of ceramide is decreased and on the other end, the level of sphingosine-1-phosphate is increased, thus altogether aggravating the cancer progression. In addition, cancer cells with upregulated AC expression exhibited increased cell proliferation, metastasis, chemoresistance, radioresistance and numerous strategies were developed in the past to effectively target the enzyme. Gene silencing and pharmacological inhibition of AC sensitized the resistant cells to chemo/radiotherapy thereby promoting cell death. The core objective of this review is to explore AC mediated tumour progression and the potential role of AC inhibitors in various cancer cell lines/models.

Nicotine promotes tumor progression and epithelial-mesenchymal transition by regulating the miR-155-5p/NDFIP1 axis in pancreatic ductal adenocarcinoma

BACKGROUND

Nicotine, the major component of cigarette smoke, has been reported to promote pancreatic ductal adenocarcinoma (PDAC) growth and invasion. Deregulation of microRNA (miRNA) expression is found in many cancers, including PDAC. The effects of nicotine on miRNAs change in PDAC progression remain unknown.

METHODS

The effects of cigarette smoking/nicotine exposure on PDAC cell lines and tissues were evaluated. Quantitative real-time PCR and in situ hybridization assays were used to determine miR-155-5p expression in human PDAC tissue and cell lines upon cigarette smoking/nicotine exposure. Bioinformatics, loss-of-function experiments, luciferase reporter assay were performed to validate Nedd4 family interacting protein 1 (NDFIP1) as a direct target of miR-155-5p. The potentials of systemic miR-155-5p inhibitor-based therapy in overcoming nicotine exposure were evaluated in tumor xenograft model.

RESULTS

Nicotine promoted PDAC cells proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) in a dose-response manner. MiR-155-5p was found to be highly expressed in PDAC cell lines and tissues upon cigarette smoking/nicotine exposure. Functional studies showed that miR-155-5p knockdown could override the enhancement of oncogenic activity due to nicotine exposure in vitro and in vivo by directly interacting with the 3' untranslated regions (UTRs) of NDFIP1.

CONCLUSIONS

These data demonstrate that nicotine-regulated miR-155-5p/NDFIP1 promotes tumor progression and EMT of PDAC.

Metabolic reprogramming by tobacco-specific nitrosamines (TSNAs) in cancer

Metabolic reprogramming is a hallmark of cancer and the link between oncogenes activation, tumor supressors inactivation and bioenergetics modulation is well established. However, numerous carcinogenic environmental factors are responsible for early cancer initiation and their impact on metabolic reprogramming just starts to be deciphered. For instance, it was recently shown that UVB irradiation triggers metabolic reprogramming at the pre-cancer stage with implication for skin cancer detection and therapy. These observations foster the need to study the early changes in tissue metabolism following exposure to other carcinogenic events. According to the International Agency for Research on Cancer (IARC), tobacco smoke is a major class I-carcinogenic environmental factor that contains different carcinogens, but little is known on the impact of tobacco smoke on tissue metabolism and its participation to cancer initiation. In particular, tobacco-specific nitrosamines (TSNAs) play a central role in tobacco-smoke mediated cancer initiation. Here we describe the recent advances that have led to a new hypothesis regarding the link between nitrosamines signaling and metabolic reprogramming in cancer.

MicroRNAs as Epigenetic Targets of Cigarette Smoke During Embryonic Development

The adverse developmental effects of exposure to Cigarette Smoke (CS) during pregnancy are documented in this paper. These include low birth weight, congenital anomalies, preterm birth, fetal mortality and morbidity. The current biological thought now recognizes that epigenetics represents a fundamental contributing process in embryogenesis, and that the environment can have a profound effect on shaping the epigenome. It has become increasingly recognized that genes encoding microRNAs (miRNAs) might be potential loci for congenital disabilities. One means by which CS can cause developmental anomalies may be through epigenetic mechanisms involving altered miRNA expression. While several studies have focused on genes affected by CS during embryonic/ fetal development, there is a paucity of knowledge on the involvement of miRNAs in this process. This brief review summarizes the current state of knowledge in this area.

Integrative analysis of genetic and epigenetic profiling of lung squamous cell carcinoma (LSCC) patients to identify smoking level relevant biomarkers

Background

Incidence and mortality of lung cancer have dramatically decreased during the last decades, yet still approximately 160,000 deaths per year occurred in United States. Smoking intensity, duration, starting age, as well as environmental cofactors including air-pollution, showed strong association with major types of lung cancer. Lung squamous cell carcinoma is a subtype of non-small cell lung cancer, which represents 25% of the cases. Thus, exploring the molecular pathogenic mechanisms of lung squamous cell carcinoma plays crucial roles in lung cancer clinical diagnosis and therapy.

Results

In this study, we performed integrative analyses on 299 comparative datasets of RNA-seq and methylation data, collected from 513 lung squamous cell carcinoma cases in The Cancer Genome Atlas. The data were divided into high and low smoking groups based on smoking intensity (Numbers of packs per year). We identified 1002 significantly up-regulated genes and 534 significantly down-regulated genes, and explored their cellular functions and signaling pathways by bioconductor packages GOseq and KEGG. Global methylation status was analyzed and visualized in circular plot by CIRCOS. RNA-and methylation data were correlatively analyzed, and 24 unique genes were identified, for further investigation of regional CpG sites' interactive patterns by bioconductor package coMET. AIRE, PENK, and SLC6A3 were the top 3 genes in the high and low smoking groups with significant differences.

Conclusions

Gene functions and DNA methylation patterns of these 24 genes are important and useful in disclosing the differences of gene expression and methylation profiling caused by different smoking levels.

A systematic review of smoking-related epigenetic alterations

The aim of this study is to provide a systematic review of the known epigenetic alterations caused by cigarette smoke; establish an evidence-based perspective of their clinical value for screening, diagnosis, and treatment of smoke-related disorders; and discuss the challenges and ethical concerns associated with epigenetic studies. A well-defined, reproducible search strategy was employed to identify relevant literature (clinical, cellular, and animal-based) between 2000 and 2019 based on AMSTAR guidelines. A total of 80 studies were identified that reported alterations in DNA methylation, histone modifications, and miRNA expression following exposure to cigarette smoke. Changes in DNA methylation were most extensively documented for genes including AHRR, F2RL3, DAPK, and p16 after exposure to cigarette smoke. Likewise, miR16, miR21, miR146, and miR222 were identified to be differentially expressed in smokers and exhibit potential as biomarkers for determining susceptibility to COPD. We also identified 22 studies highlighting the transgenerational effects of maternal and paternal smoking on offspring. This systematic review lists the epigenetic events/alterations known to occur in response to cigarette smoke exposure and identifies the major genes and miRNAs that are potential targets for translational research in associated pathologies. Importantly, the limitations and ethical concerns related to epigenetic studies are also highlighted, as are the effects on the ability to address specific questions associated with exposure to tobacco/cigarette smoke. In the future, improved interpretation of epigenetic signatures will lead to their increased use as biomarkers and/or in drug development.

The Roles of MicroRNA in Lung Cancer

Lung cancer is the most devastating malignancy in the world. Beyond genetic research, epigenomic studies—especially investigations of microRNAs—have grown rapidly in quantity and quality in the past decade. This has enriched our understanding about basic cancer biology and lit up the opportunities for potential therapeutic development. In this review, we summarize the involvement of microRNAs in lung cancer carcinogenesis and behavior, by illustrating the relationship to each cancer hallmark capability, and in addition, we briefly describe the clinical applications of microRNAs in lung cancer diagnosis and prognosis. Finally, we discuss the potential therapeutic use of microRNAs in lung cancer.

Genetic Susceptibility for Cervical Cancer in African Populations: What Are the Host Genetic Drivers?

Human papillomavirus (HPV) is an essential but not a sufficient cervical cancer etiological factor. Cancer promoters, such as host genetic mutations, significantly modulate therapeutic responses and susceptibility. In cervical cancer, of interest have been viral clearing genes and HPV oncoprotein targets, for which conflicting data have been reported among different populations. This expert analysis evaluates cervical cancer genetic susceptibility biomarkers studied in African populations. Notably, the past decade has seen Africa as a hotbed of biomarker and precision medicine innovations, thus potentially informing worldwide biomarker development strategies. We conducted a critical literature search in PubMed/MEDLINE, Google Scholar, and Scopus databases for case-control studies reporting on cervical cancer genetic polymorphisms among Africans. We found that seven African countries conducted cervical cancer molecular epidemiology studies in one of Casp8, p53, CCR2, FASL, HLA, IL10, TGF-beta, and TNF-alpha genes. This analysis reveals a remarkable gap in cervical cancer molecular epidemiology among Africans, whereas cervical cancer continues to disproportionately have an impact on African populations. Genome-wide association, whole exome- and whole-genome sequencing studies confirmed the contribution of candidate genes in cervical cancer. With such advances and omics technologies, the role of genetic susceptibility biomarkers can be exploited to develop novel interventions to improve current screening, diagnostic and prognostic methods worldwide. Exploring these genetic variations is crucial because African populations are genetically diverse and some variants or their combined effects are yet to be discovered and translated into tangible clinical applications. Thus, translational medicine and flourishing system sciences in Africa warrant further emphasis in the coming decade.

Circular RNA Complement Factor H (CFH) Promotes Glioma Progression by Sponging miR-149 and Regulating AKT1

Background

Circular RNAs (circRNAs) are widely expressed in mammals and can regulate the development and progression of human tumors. has_circ_0015758 (circ-CFH) is an exon circRNA transcript from the GRCh37/hg19 fragment of chromosome 1 and is homologous to the protein-coding gene complement factor H (CFH). Currently, the function of circ-CFH in glioma remains unclear.

Material/Methods

In our study, circ-CFH, miR-149, and Akt1 mRNA expression levels were analyzed by qRT-PCR assays. To investigate the function of circ-CFH in cell proliferation, circ-CFH knockdown models were established by using circ-CFH siRNAs. Cell proliferation abilities were measured by CCK-8 and colony formation assays and in vivo experiments. In addition, the interaction between circ-CFH and miR-149 was assessed by luciferase reporter assays.

Results

Circ-CFH expression was significantly upregulated in glioma tissue and was correlated with tumor grade. Circ-CFH expression levels were also markedly higher in U251 and U373 glioma cell lines. Circ-CFH knockdown inhibited cell proliferation and colony formation abilities. Luciferase assays indicated that circ-CFH functions as a miR-149 sponge and inhibits its function in U251 and U373 cells. Subsequently, AKT1 was identified as a direct target of the circ-CFH/miR-149 axis.

Conclusions

Circ-CFH promotes glioma progression by sponging miR-149 and regulating the AKT1 signaling pathway. The circ-CFH/miR-149/AKT1 regulation axis may be a potential target for glioma therapy.

Cigarette smoke induces mitochondrial metabolic reprogramming in lung cells

Cellular transformation owing to cigarette smoking is due to chronic exposure and not acute. However, systematic studies to understand the molecular alterations in lung cells due to cigarette smoke are lacking. To understand these molecular alterations induced by chronic cigarette smoke exposure, we carried out tandem mass tag (TMT) based temporal proteomic profiling of lung cells exposed to cigarette smoke for upto 12months. We identified 2620 proteins in total, of which 671 proteins were differentially expressed (1.5-fold) after 12months of exposure. Prolonged exposure of lung cells to smoke for 12months revealed dysregulation of oxidative phosphorylation and overexpression of enzymes involved in TCA cycle. In addition, we also observed overexpression of enzymes involved in glutamine metabolism, fatty acid degradation and lactate synthesis. This could possibly explain the availability of alternative source of carbon to TCA cycle apart from glycolytic pyruvate. Our data indicates that chronic exposure to cigarette smoke induces mitochondrial metabolic reprogramming in cells to support growth and survival.

Unique circulating microRNAs in relation to EGFR mutation status in Japanese smoker male with lung adenocarcinoma

The incidence of lung adenocarcinoma has been increasing recently in smokers. The molecular target therapy has been developed for lung adenocarcinoma patients harboring EGFR gene mutation. However, the treatment modalities for patients without mutation are currently limited. Thus, analysis of EGFR gene mutation status at early stage is important strategy to classify the patients for improving treatments and prognosis efficiently. This study aimed to identify microRNA (miRNA) signature in relation to mutation status in EGFR gene in early stage of lung adenocarcinoma male patients with smoking history. MiRNA profiles were assessed by microarray in paired plasma and tissue pooled from 10 EGFR wild type (EGFR-wt) and 10 EGFR mutated (EGFR-mut) patients. Expressions of selected miRNAs were verified further by real-time qRT-PCR in 83 plasma samples consisting of 55 EGFR-wt patients and 28 EGFR-mut patients and their correlation with clinicopathological parameters and EGFR gene mutation status were evaluated. We found that seven miRNAs (miR-16-5p, miR-23a-3p, miR-103a-3p, miR122-5p, miR-223-3p, miR-346 and miR-451a) were differentially expressed in stage I and stage I+II. Especially, miR-23a-3p was only miRNA shown higher expression in EGFR-wt patients than EGFR-mut patients. Thus, our findings could be useful non-invasive biomarkers to differentiate mutation status in EGFR gene in smoker lung adenocarcinoma male patients.