Downregulation of HIF-1α inhibits the proliferation and invasion of non-small cell lung cancer NCI-H157 cells

The Regulation Pathway of VEGF Gene Expression Is Different between 2D Cells and 3D Spheroids in Human Lung Cancer Cells

Angiogenesis is involved in the malignant transformation of cancers. Vascular endothelial growth factor (VEGF) is important in inducing angiogenesis. Cultured cells play an important role in analyzing the regulation of VEGF expression, and it is revealed that VEGF expression is induced under hypoxia. However, it has been shown that there are differences in the pathway for gene expression between two-dimensional (2D) cells and in vivo cells. Three-dimensional (3D) spheroids constructed in 3D culture with a gene expression pattern more similar to that of in vivo cells than 2D cells have been used to solve this problem. This study analyzed the VEGF gene expression pathway in 3D spheroids of human lung cancer cells, A549 and H1703. Hypoxia-inducible factor-1α (HIF-1α) and aryl hydrocarbon receptor nuclear translocator (ARNT) regulated VEGF gene expression in 3D spheroids. However, VEGF gene expression was not regulated by HIF-1α in 2D cells. To conclude, we found that the regulatory pathway of VEGF gene expression is different between 2D cells and 3D spheroids in human lung cancer cells. These results suggest the possibility of a new VEGF gene expression regulation pathway in vivo. In addition, they show useful knowledge for the analysis of angiogenesis induction mechanisms and also demonstrate the usefulness of 3D spheroids.

A unique amphiphilic triblock copolymer, nontoxic to human blood and potential supramolecular drug delivery system for dexamethasone

The drug delivery system (DDS) often causes toxicity, triggering undesired cellular injuries. Thus, developing supramolecules used as DDS with tunable self-assembly and nontoxic behavior is highly desired. To address this, we aimed to develop a tunable amphiphilic ABA-type triblock copolymer that is nontoxic to human blood cells but also capable of self-assembling, binding and releasing the clinically used drug dexamethasone. We synthesized an ABA-type amphiphilic triblock copolymer (P2L) by incorporating tetra(aniline) TANI as a hydrophobic and redox active segment along with monomethoxy end-capped polyethylene glycol (mPEG2k; Mw = 2000 g mol-1) as biocompatible, flexible and hydrophilic part. Cell cytotoxicity was measured in whole human blood in vitro and lung cancer cells. Polymer-drug interactions were investigated by UV-Vis spectroscopy and computational analysis. Our synthesized copolymer P2L exhibited tuned self-assembly behavior with and without external stimuli and showed no toxicity in human blood samples. Computational analysis showed that P2L can encapsulate the clinically used drug dexamethasone and that drug uptake or release can also be triggered under oxidation or low pH conditions. In conclusion, copolymer P2L is nontoxic to human blood cells with the potential to carry and release anticancer/anti-inflammatory drug dexamethasone. These findings may open up further investigations into implantable drug delivery systems/devices with precise drug administration and controlled release at specific locations.

MiR-199a-5p-HIF-1α-STAT3 Positive Feedback Loop Contributes to the Progression of Non-Small Cell Lung Cancer

Background: Non-small cell lung cancer (NSCLC) is the most common malignancy worldwide. MiR-199a-5p has been reported to play important roles in multiple tumors, inclusive of NSCLC. However, little is definitively known pertaining to its explicit mechanism of action in NSCLC. Methods: The expressions of miR-199a-5p and hypoxia-inducible factor-1α (HIF-1α) mRNA were quantified employing qRT-PCR. H1299 and A549 cells were transiently transfected with miR-199a-5p mimics or inhibitors. Then, CCK-8 assays, flow cytometry analysis, and Transwell assay were performed for detecting cell proliferation, cell cycle, apoptosis, migration, and invasion of NSCLC cells, respectively. HIF-1α, signal transducer and activator of transcription 3 (STAT3), and p-STAT3 expressions were detected via Western blotting. Bioinformatic analysis and dual-luciferase assay were performed to investigate the interactions among miR-199a-5p, HIF-1α, and STAT3. Xenograft models were established with nude mice for further analyzing the bevacizumab resistance of NSCLC cells. Results: MiR-199a-5p expression was markedly attenuated in NSCLC tissues and cell lines. Overexpression of miR-199a-5p repressed the proliferation, migration, and invasion but induced the apoptosis of NSCLC cells. HIF-1α was identified as a direct target of miR-199a-5p. There was a positive feedback loop among miR-199a-5p, HIF-1α, and STAT3. Co-transfection of HIF-1α or STAT3 overexpression plasmids counteracted the effects of miR-199a-5p. In vivo experiments indicated that the feedback loop was in association with the bevacizumab resistance of NSCLC cells. Conclusion: MiR-199a-5p blocked the progression of NSCLC and sensitized NSCLC cells to bevacizumab by suppressing HIF-1α and STAT3, while the HIF-1α/STAT3 axis suppressed the expression of miR-199a-5p, which forms a positive feedback loop to promote the sustaining progression of NSCLC.

Field Cancerization in NSCLC: A New Perspective on MicroRNAs in Macrophage Polarization

Lung cancer is currently the first cause of cancer-related death. The major lung cancer subtype is non-small cell lung cancers (NSCLC), which accounts for approximatively 85% of cases. The major carcinogenic associated with lung cancer is tobacco smoke, which produces long-lasting and progressive damage to the respiratory tract. The progressive and diffuse alterations that occur in the respiratory tract of patients with cancer and premalignant lesions have been described as field cancerization. At the level of tumor cells, adjacent tumor microenvironment (TME) and cancerized field are taking place dynamic interactions through direct cell-to-cell communication or through extracellular vesicles. These molecular messages exchanged between tumor and nontumor cells are represented by proteins, noncoding RNAs (ncRNAs) and microRNAs (miRNAs). In this paper, we analyze the miRNA roles in the macrophage polarization at the level of TME and cancerized field in NSCLC. Identifying molecular players that can influence the phenotypic states at the level of malignant cells, tumor microenvironment and cancerized field can provide us new insights into tumor regulatory mechanisms that can be further modulated to restore the immunogenic capacity of the TME. This approach could revert alterations in the cancerized field and could enhance currently available therapy approaches.

Effects of Hypoxia and Radiation-Induced Exosomes on Migration of Lung Cancer Cells and Angiogenesis of Umbilical Vein Endothelial Cells

Numerous studies have shown that exosomes play important roles in tumor biology development. However, the function of exosomal protein in cancer progression under different oxygen condition after irradiation is poorly understood. In this study, non-small cell lung cancer (NSCLC) A549 cells were γ-ray irradiated under normoxic or hypoxic conditions, then the exosomes released from the irradiated cells were collected and co-cultured with nonirradiated A549 cells or human umbilical vein endothelial cells (HUVECs). It was found that the exosomes significantly promoted the proliferation, migration and invasion of A549 cells as well as the proliferation and angiogenesis of HUVECs. Moreover, the exosomes released from hypoxic cells and/or irradiated cells had more powerful driving force in tumor progression compared to that generated from normoxia cells. Meanwhile, the proteins contained in the exosomes derived from A549 cells under different conditions were detected using tandem mass tag (TMT), and their expression profiles were analyzed. It was found that the exosome-derived protein of angiopoietin-like 4 (ANGPTL4) contributed to the migration of A549 cells as well as the angiogenesis of HUVECs, suggesting its potential as an effective diagnostic biomarker of metastasis and even a therapeutic target of lung cancer.

The Impact of Ang-(1-9) and Ang-(3-7) on the Biological Properties of Prostate Cancer Cells by Modulation of Inflammatory and Steroidogenesis Pathway Genes

The local renin–angiotensin system (RAS) plays an important role in the pathophysiology of the prostate, including cancer development and progression. The Ang-(1-9) and Ang-(3-7) are the less known active peptides of RAS. This study examines the influence of these two peptide hormones on the metabolic activity, proliferation and migration of prostate cancer cells. Significant changes in MTT dye reduction were observed depending on the type of angiotensin and its concentration as well as time of incubation. Ang-(1-9) did not regulate the 2D cell division of either prostate cancer lines however, it reduced the size of LNCaP colonies formed in soft agar, maybe through down-regulation of the HIF1a gene. Ang-(3-7) increased the number of PC3 cells in the S phase and improved anchorage-independent growth as well as mobility. In this case, a significant increase in MKI67, BIRC5, and CDH-1 gene expression was also observed as well as all members of the NF-kB family. Furthermore, we speculate that this peptide can repress the proliferation of LNCaP cells by NOS3-mediated G2/M cell cycle arrest. No changes in expression of BIRC5 and BCL2/BAX ratio were observed but a decrease mRNA proapoptotic BAD gene was seen. In the both lines, Ang-(3-7) improved ROCK1 gene expression however, increased VEGF and NOS3 mRNA was only seen in the PC3 or LNCaP cells, respectively. Interestingly, it appears that Ang-(1-9) and Ang-(3-7) can modulate the level of steroidogenic enzymes responsible for converting cholesterol to testosterone in both prostate cancer lines. Furthermore, in PC3 cells, Ang-(1-9) upregulated AR expression while Ang-(3-7) upregulated the expression of both estrogen receptor genes. Ang-(1-9) and Ang-(3-7) can impact on biological properties of prostate cancer cells by modulating inflammatory and steroidogenesis pathway genes, among others.

The role of monoamine oxidase A in HPV-16 E7-induced epithelial-mesenchymal transition and HIF-1α protein accumulation in non-small cell lung cancer cells

Our previous studies have found that human papillomavirus (HPV)-16 E7 oncoprotein promotes epithelial-mesenchymal transition (EMT) and hypoxia-inducible factor-1α (HIF-1α) protein accumulation in non-small cell lung cancer (NSCLC) cells and monoamine oxidase A (MAOA) is highly expressed in NSCLC tissues. Here, we further explored the role of MAOA in HPV-16 E7-induced EMT and HIF-1α protein accumulation in A549 and NCI-H460 NSCLC cells. Our results showed that HPV-16 E7 enhanced MAOA expression in NSCLC cells. Additionally, MAOA knockout inhibited HPV-16 E7-induced migration, invasion, and EMT, and significantly reduced HPV-16 E7-induced ROS generation and HIF-1α protein accumulation via promoting its degradation. Furthermore, MAOA knockout suppressed HPV-16 E7-induced ERK1/2 activation. In vivo, MAOA knockout inhibited tumor growth, metastasis, and the expression of EMT-related markers and HIF-1α proteins induced by HPV-16 E7 in NCI-H460 NSCLC subcutaneous xenograft and in situ intrapulmonary models of nude mice. Taken together, our findings provide evidence that MAOA plays a key role in EMT and HIF-1α protein accumulation induced by HPV-16 E7 in NSCLC cells, suggesting that MAOA may be a potential therapeutic target for HPV-related NSCLC.

Benzo(a)pyrene affects proliferation with reference to metabolic genes and ROS/HIF-1α/HO-1 signaling in A549 and MCF-7 cancer cells

Benzo(a)pyrene (BaP) is a representative polycyclic aromatic hydrocarbon (PAH) compound, which has been implicated in cancer initiation and promotion. Although BaP is one of the most extensively studied pollutants, the underlying mechanisms through which BaP affects reactive oxygen species (ROS)/hypoxia-inducible factor 1α (HIF-1α)/heme oxygenase 1(HO-1) signaling during lung or breast carcinogenesis are not yet fully understood. In this study, we analyzed the effects of 0 (control), 1, 5, or 25 µM BaP exposure on A549 and MCF-7 cancer cells, by evaluating cell viability, cell cycle, and regulatory protein expression, metabolic gene expression, and ROS/HIF-1α/HO-1 signaling. Cell viability increased following exposure to 1 and 5 µM BaP in A549 cells but decreased following exposure to all concentrations of BaP in MCF-7 cells. BaP significantly increased the proportions of cells in S and G2/M phases, with concomitant reductions in the proportions of cells in G0/G1 phase, following 5 and 25 µM exposure, which was accompanied by the upregulation of the regulatory proteins cyclin A, cyclin B, cyclin-dependent kinase (CDK)1, and CDK2. The subsequent upregulation of cytochrome p450 (CYP)1A1, CYP1B1, CYP3A4, epoxide hydrolase (EH), aldo-keto reductase (AKRC1) expression, and the attenuation of multi-drug resistance protein 4 (MRP4), glutathione-S-transferase (GST)1A1, and GST1B1 were also observed in both cell lines. Moreover, the induction of ROS and the modulation of HIF-1α and HO-1 were observed after BaP exposure. Taken together, these findings suggest that BaP affects proliferation with reference to metabolic genes and ROS/HIF-1α/HO-1 signaling in A549 and MCF-7 cancer cells.

The self-assembled α-lactalbumin-oleic acid complex inhibits ATP supply from both glycolysis and the TCA cycle in HepG2 cells and HepG2-bearing nude mice

Energy metabolism has been a predominant target for anti-cancer drug development. The self-assembled anti-tumor α-lactalbumin-oleic acid complex (α-LA-OA) affects the energy metabolism of tumor cells, however, the role of targeting energy metabolism in its anti-tumor mechanism still needs to be clarified. α-LA assembled with OA to form a complex with an average diameter of 144.1 ± 7.241 nm, which is 10-fold larger than α-LA alone. Furthermore, the self-assembled α-LA-OA inhibited the ATP supply from both glycolysis and oxidative phosphorylation in HepG2 cells and HepG2-bearing nude mice. The gene expression of enzymes involved in glycolysis (HK2, aldose, PKM2, LDHB) and oxidative phosphorylation (CS, ACO2, IDH2, SDHA) was inhibited. This inhibitory effect was also evident by increased phosphorylation of AMPKα. α-LA-OA also suppressed the expression of HIF-1α and increased the expression of activated caspase-3. These findings demonstrate that the anti-tumor mechanism of α-LA-OA may be related to its inhibitory effect on the ATP supply, which then activates programmed cell death pathways. This study also indicated that α-LA-OA is a potent anti-tumor agent that targets the energy metabolism of tumor cells.

Role of VEGFs/VEGFR-1 Signaling and its Inhibition in Modulating Tumor Invasion: Experimental Evidence in Different Metastatic Cancer Models

The vascular endothelial growth factor (VEGF) family members, VEGF-A, placenta growth factor (PlGF), and to a lesser extent VEGF-B, play an essential role in tumor-associated angiogenesis, tissue infiltration, and metastasis formation. Although VEGF-A can activate both VEGFR-1 and VEGFR-2 membrane receptors, PlGF and VEGF-B exclusively interact with VEGFR-1. Differently from VEGFR-2, which is involved both in physiological and pathological angiogenesis, in the adult VEGFR-1 is required only for pathological angiogenesis. Besides this role in tumor endothelium, ligand-mediated stimulation of VEGFR-1 expressed in tumor cells may directly induce cell chemotaxis and extracellular matrix invasion. Furthermore, VEGFR-1 activation in myeloid progenitors and tumor-associated macrophages favors cancer immune escape through the release of immunosuppressive cytokines. These properties have prompted a number of preclinical and clinical studies to analyze VEGFR-1 involvement in the metastatic process. The aim of the present review is to highlight the contribution of VEGFs/VEGFR-1 signaling in the progression of different tumor types and to provide an overview of the therapeutic approaches targeting VEGFR-1 currently under investigation.

Ginsenoside Rh2 Inhibits Migration of Lung Cancer Cells under Hypoxia via mir-491

Background:

Ginsenoside Rh2 (Rh2), which is extracted from ginseng, exerts antitumor activity. Here we would like to study the role of Rh2 on hypoxia-induced migration in lung adenocarcinoma.

Methods:

Lung adenocarcinoma A549 and H1299 cells were cultured in 1% O2 condition to mimic the hypoxic tumor microenvironment. The migrations of cancer cells were measured by transwell assay and scratch assay.

Results:

Rh2 could inhibit hypoxia-induced A549 and H1299 cell migration via increase of mir-491 expression. Further, mir-491 antisense oligonucleotide could repress hypoxia-induced migration and the expression of matrix metalloproteinase (MMP)-9 expression in Rh2-treated A549 cells.

Conclusion:

These findings suggest that Rh2 exerts anti-metastasis activity in the hypoxic tumor microenvironment in lung adenocarcinoma cells via mir-491.

Prolyl hydroxylase 3 involvement in lung cancer progression under hypoxic conditions: association with hypoxia-inducible factor-1α and pyruvate kinase M2

Background

Previous studies have suggested that the functions of prolyl hydroxylase 3 (PHD3) in tumor growth, apoptosis and angiogenesis are essentially dependent on hypoxia-inducible factor (HIF)-1α signaling. Nevertheless, whether PHD3 represents a promising tumor suppressor target remains to be clarified. To provide insight into the therapeutic potential of PHD3 in lung cancer, this study examined the effects of PHD3 expression on HIF-1α and pyruvate kinase M2 (PKM2), as well as on lung cancer cell proliferation, migration, and invasion.

Methods

The model of hypoxia was established in A549 and SK-MES-1 cells with 200 µM CoCl2 treatment, and verified by western blot and immunocytochemical staining. The expression levels of PKM2 and HIF-1α were determined by western blot after overexpression or depletion of PHD3 in A549 and SK-MES-1 cells. In addition, cell viability, migration and invasion were measured, respectively.

Results

Establishment of hypoxia in A549 and SK-MES-1 cells resulted in significant decreases in PHD3 expression and remarkable increase in PKM2 expression in 24 hrs. Overexpression of PHD3 in A549 and SK-MES-1 cells decreased HIF-1α and PKM2 expression. In contrast, PHD3 knockdown increased HIF-1α and PKM2 (P<0.05). In addition, the viability, migration and invasion of A549 and SK-MES-1 cells were significantly decreased with PHD3 overexpression, but dramatically increased with PHD3 depletion (P<0.05).

Conclusions

PHD3 is involved in lung cancer progression, and might be a promising therapeutic target for cancers.

Correlation and expression analysis of hypoxia-inducible factor 1α, glucose transporter 1 and lactate dehydrogenase 5 in human gastric cancer

The development and identification of novel potential targeting sites for intervention therapy are essential in the search for improved treatment methods for gastric cancer (GC). Previously, it has been reported that hypoxia inducible factor-1α (HIF-1α) is a potential target gene involved in the endogenous hypoxic response and bioenergetic metabolism of GC cells. In the present study, with the assumption of a close interplay among HIF-1α, glucose transporter 1 (GLUT1) and lactate dehydrogenase-5 (LDH-5), 85 patients with GC were recruited and the protein and gene expression levels of HIF-1α, GLUT1 and LDH-5 in tumor tissues were evaluated in order to assess clinical correlations and co-expression patterns, using Immunohistochemical staining and reverse transcription-quantitative polymerase chain reaction. The results demonstrated that the protein and gene expression levels of HIF-1α were significantly associated with the depth of invasion, nodal metastasis, clinical stage, differentiation and distant metastasis. Consistent with the protein expression results, the mRNA expression levels of the genes coding for GLUT1 and LDH-5 were clearly associated with tumor size, depth of invasion, distant metastasis, clinical stage and differentiation. Correlation analysis of HIF-1α with GLUT1 and LDH-5 at the protein and mRNA expression levels in gastric carcinoma indicated that HIF-1α expression was positively correlated with the expression of GLUT1 (P<0.01, r=0.765 for mRNA expression; P<0.01, r=0.697 for protein expression) and LDH-5 (P<0.01, r=0.892 for mRNA expression; P<0.01, r=0.783 for protein expression) at the mRNA and protein levels. Therefore, it may be concluded that HIF-1α, GLUT1 and LDH-5 are potential target genes involved in the endogenous tumor response to hypoxia and the inhibition of tumor energy metabolism, highlighting a novel therapeutic target for GC.

Cytochalasin H Inhibits Angiogenesis via the Suppression of HIF-1α Protein Accumulation and VEGF Expression through PI3K/AKT/P70S6K and ERK1/2 Signaling Pathways in Non-Small Cell Lung Cancer Cells

Our previous study has demonstrated that cytochalasin H (CyH) isolated from mangrove-derived endophytic fungus induces apoptosis and inhibits migration in A549 non-small cell lung cancer (NSCLC) cells. In this study, we further explored the effect of CyH on angiogenesis in NSCLC cells and the underlying molecular mechanisms. A549 and H460 NSCLC cells were treated with different concentrations of CyH for 24 h. The effects of CyH on NSCLC angiogenesis in vitro and in vivo were investigated. Hypoxia inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) expression in xenografted NSCLC of nude mice was analyzed by immunohistochemistry. ELISA was used to analyze the concentration of VEGF in the conditioned media derived from treated and untreated NSCLC cells. Western blot was performed to detect the levels of HIF-1α, p-AKT, p-P70S6K, and p-ERK1/2 proteins, and RT-qPCR was used to determine the levels of HIF-1α and VEGF mRNA in A549 and H460 cells. Our results showed that CyH significantly inhibited angiogenesis in vitro and in vivo, and suppressed the hemoglobin content and HIF-1α and VEGF protein expression in xenografted NSCLC tissues of nude mice. Meanwhile, CyH inhibited the secretion of VEGF protein and the expression of HIF-1α protein in A549 and H460 cells. Moreover, CyH had a significant inhibitory effect on VEGF mRNA expression but had no effect on HIF-1α mRNA expression, and CyH inhibited HIF-1α protein expression by promoting the degradation of HIF-1α protein in A549 and H460 cells. Additionally, CyH dramatically inhibited AKT, P70S6K, and ERK1/2 activation in A549 and H460 cells. Taken together, our results suggest that CyH can inhibit NSCLC angiogenesis by the suppression of HIF-1α protein accumulation and VEGF expression through PI3K/AKT/P70S6K and ERK1/2 signaling pathways.

Down-regulation of HIF-1α inhibits the proliferation, migration, and invasion of gastric cancer by inhibiting PI3K/AKT pathway and VEGF expression

In view of the high incidence of gastric cancer and the functions of hypoxia-inducible factor 1α (HIF-1α), our study aimed to investigate the functionality of HIF-1α in gastric cancer, and to explore the diagnostic and prognostic values of HIF-1α for this disease. Expression of HIF-1α in tumor tissues and adjacent healthy tissues as well as serum collected from both gastric cancer patients and normal healthy controls was detected by qRT-PCR. Survival analysis was performed using Kaplan–Meier method. HIF-1α siRNA silencing cell lines were established. Effects of HIF-1α siRNA silencing as well as PI3K activator sc3036 on proliferation, migration, and invasion of gastric cancer cells were detected by Cell counting kit (CCK-8) assay, and Transwell migration and invasion assay. Effects of HIF-1α siRNA silencing on AKT and VEGF were detected by Western blot. Expression of HIF-1α was significantly down-regulated in tumor tissues than in adjacent healthy tissues in most gastric cancer patients. Serum levels of HIF-1α were also higher in gastric cancer patients than in normal healthy people. Serum HIF-1α showed promising diagnostic and prognostic values for gastric cancer. HIF-1α siRNA silencing inhibited the proliferation, migration, and invasion of gastric cancer cells, while PI3K activator sc3036 treatment reduced those inhibitory effects. Down-regulation of HIF-1α can inhibit the proliferation, migration, and invasion of gastric cancer possibly by inhibiting PI3K/AKT pathway and VEGF expression.

Aggressive serous epithelial ovarian cancer is potentially propagated by EpCAM+CD45+ phenotype

Epithelial ovarian carcinoma (EOC) patients often acquire resistance against common chemotherapeutic drugs like paclitaxel and cisplatin. The mechanism responsible for the same is ambiguous. We have identified a putative drug-resistant tumour cell phenotype (EpCAM⁺CD45⁺) in the ascitic fluid of EOC patients, which appears to originate from the primary tumour. These cells represent the major tumour burden and are more drug resistant compared to EpCAM⁺ tumour cells due to the over-expression of SIRT1, ABCA1 and BCL2 genes. We have found that the entire EpCAM⁺CD45⁺ population is highly invasive with signature mesenchymal gene expression and also consists of subpopulations of ovarian cancer stem cells (CD133⁺ and CD117⁺CD44⁺). Additionally, we demonstrate that the EpCAM⁺CD45⁺ tumour cells over-express major histocompatibility complex class I antigen, which enable them to evade the natural killer cell-mediated immune surveillance. Preliminary evidence obtained in OVCAR-5 cells suggests that exosomes, secreted by non-tumour cells of the ascitic fluid, play an important role in rendering drug resistance and invasive properties to the cancer cells. Identification of such aggressive tumour cells and deciphering their origin is important for designing better drug targets for EOC.

[Association of Indoor Air Pollution, Single Nucleotide Polymorphism of HIF-1α Gene with Susceptibility to Lung Cancer in Han Population in Fujian Province]

BACKGROUND

Hypoxia inducible factor-1α (HIF-1α) is associated with the progression and metastasis of lung cancer. There are, however, few studies on the relationship between the single nucleotide polymorphisms of HIF-1α and susceptibility to lung cancer. Therefore, we aimed to investigate the relationship between indoor air pollution, HIF-1α rs2057482, and the susceptibility to primary lung cancer of the Fujian Han population.

METHODS

The present study is a hospital-based case-control study. We recruited 1,096 lung cancer and 1,110 controls that were admitted to the Department of Thoracic Surgery of the First Affiliated Hospital and Union Hospital of Fujian Medical University and Fuzhou General Hospital of Nanjing Military Region from January 2006 to December 2012. The primary lung cancer cases were identified via pathological methods. Both case and control groups received questionnaires. Genotyping of HIF-1α gene rs2057482 locus polymorphism in all subjects were analyzed by MALDI-TOF-MS technique.

RESULTS

Individuals who carried the T-genotype of HIF-1α rs2057482 were more susceptible to small cell carcinoma (odds ratio of 1.725, 95%CI: 1.047-2.842). After adjusting for general and lung cancer-related factors, we found that in the co-dominant genetic model, rs2057482 TT carriers were 2.195 times more likely to develop lung cancer than CC carriers (95%CI: 1.038-4.463) in the population that were exposed to passive smoking. In the dominant genetic model, the risk of lung cancer was 1.911 times (95%CI: 1.121-3.258) that in the carriers of the rs2057482 T allele with a family history of cancer. In the recessive genetic model, rs2057482 TT carriers had a 0.159-fold increased risk of lung cancer (95%CI: 0.028-0.920) than TC+CC carriers in people with a history of lung disease. In the additive genetic model, the risk of lung cancer in rs2057482 TC+TT carriers was 1.542 times (95%CI: 1.107-2.340) that in the CC family of people with a family history of cancer.

CONCLUSIONS

HIF-1α rs2057482 may be associated with lung cancer susceptibility.
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MicroRNA-206 attenuates the growth and angiogenesis in non-small cell lung cancer cells by blocking the 14-3-3ζ/STAT3/HIF-1α/VEGF signaling

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related mortality worldwide. Angiogenesis is the major hallmark in NSCLC. So, further elucidation of molecular mechanisms underlying the angiogenesis of NSCLC is urgently needed. Here, we found that microRNA-206 (miR-206) decreased the angiogenic ability in NSCLC via inhibiting the 14-3-3ζ/STAT3/HIF-1α/VEGF pathway. Briefly, 14-3-3ζ bond with phosphorylated-STAT3, and in turn, elevated the expression of HIF-1α. Then, by enhancing the recruitment of HIF-1α to VEGF promoter, 14-3-3ζ increased the angiogenesis. However, miR-206 decreased the angiogenesis by targeting 14-3-3ζ, and inhibiting the STAT3/HIF-1α/VEGF pathway. In NSCLC cell xenograft model, either overexpression of miR-206 or inhibition of 14-3-3ζ inhibited the STAT3/HIF-1α/VEGF pathway and decreased the tumor growth and angiogenesis. Furthermore, there was a negative correlation between miR-206 and 14-3-3ζ in NSCLC specimens. NSCLC patients with low expressions of miR-206 but high expressions of 14-3-3ζ had the worst survival. Collectively, our findings provided the underlying mechanisms of miR-206/14-3-3ζ in tumor growth and angiogenesis, and implicated miR-206 and 14-3-3ζ as potential therapeutic targets for NSCLC.