Expression In Human Lung Cancer Research Articles

The ectonucleotidase CD39 identifies tumor-reactive CD8+ T cells predictive of immune checkpoint blockade efficacy in human lung cancer

Improved identification of anti-tumor Tcells is needed to advance cancer immunotherapies. CD39 expression is a promising surrogate of tumor-reactive CD8+ Tcells. Here, we comprehensively profiled CD39 expression in human lung cancer. CD39 expression enriched for CD8+ Tcells with features of exhaustion, tumor reactivity, and clonal expansion. Flow cytometry of 440 lung cancer biospecimens revealed weak association between CD39+ CD8+ Tcells and tumoral features, such as programmed death-ligand 1 (PD-L1), tumor mutation burden, and driver mutations. Immune checkpoint blockade (ICB), but not cytotoxic chemotherapy, increased intratumoral CD39+ CD8+ Tcells. Higher baseline frequency of CD39+ CD8+ Tcells conferred improved clinical outcomes from ICB therapy. Furthermore, a gene signature of CD39+ CD8+ Tcells predicted benefit from ICB, but not chemotherapy, in a phase III clinical trial of non-small cell lung cancer. These findings highlight CD39 as a proxy of tumor-reactive CD8+ Tcells in human lung cancer.

APE1 controls DICER1 expression in NSCLC through miR-33a and miR-130b

Increasing evidence suggests different, not completely understood roles of microRNA biogenesis in the development and progression of lung cancer. The overexpression of the DNA repair protein apurinic/apyrimidinic endodeoxyribonuclease 1 (APE1) is an important cause of poor chemotherapeutic response in lung cancer and its involvement in onco-miRNAs biogenesis has been recently described. Whether APE1 regulates miRNAs acting as prognostic biomarkers of lung cancer has not been investigated, yet. In this study, we analyzed miRNAs differential expression upon APE1 depletion in the A549 lung cancer cell line using high-throughput methods. We defined a signature of 13 miRNAs that strongly correlate with APE1 expression in human lung cancer: miR-1246, miR-4488, miR-24, miR-183, miR-660, miR-130b, miR-543, miR-200c, miR-376c, miR-218, miR-146a, miR-92b and miR-33a. Functional enrichment analysis of this signature revealed its biological relevance in cancer cell proliferation and survival. We validated DICER1 as a direct functional target of the APE1-regulated miRNA-33a-5p and miR-130b-3p. Importantly, IHC analyses of different human tumors confirmed a negative correlation existing between APE1 and Dicer1 protein levels. DICER1 downregulation represents a prognostic marker of cancer development but the mechanisms at the basis of this phenomenon are still completely unknown. Our findings, suggesting that APE1 modulates DICER1 expression via miR-33a and miR-130b, reveal new mechanistic insights on DICER1 regulation, which are of relevance in lung cancer chemoresistance and cancer invasiveness.

Failure to EGFR-TKI-based therapy and tumoural progression are promoted by MEOX2/GLI1-mediated epigenetic regulation of EGFR in the human lung cancer

BackgroundMesenchyme homeobox-2 (MEOX2)-mediated regulation of glioma-associated oncogene-1 (GLI1) has been associated with poor overall survival, conferring chemoresistance in lung cancer. However, the role of MEOX2/GLI1 in resistance to epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs)-based therapy remains unexplored in human lung cancer. MethodsFunctional assays using genetic silencing strategy by short hairpin RNAs, as well as cytotoxic (tetrazolium dye MTT) and clonogenic assays, were performed to evaluate MEOX2/GLI1-induced malignancy capacity in lung cancer cells. Further analysis performed includes western blot, qPCR and ChIP-qPCR assays to identify whether MEOX2/GLI1 promote EGFR/AKT/ERK activation, as well as EGFR overexpression through epigenetic mechanisms. Finally, preclinical tumour progression in vivo and progression-free disease interval analyses in patients treated with EGFR-TKI were included. ResultsOverexpressed MEOX2/GLI1 in both EGFR wild-type and EGFR/KRAS-mutated lung cancer cells were detected and involved in the activation/expression of EGFR/AKT/ERK biomarkers. In addition, MEOX2/GLI1 was shown to be involved in the increased proliferation of tumour cells and resistance capacity to cisplatin, EGFR-TKIs (erlotinib and AZD9291 ‘osimertinib’), AZD8542-SMO, and AZD6244-MEKK1/2. In addition, we identified that MEOX2/GLI1 promote lung tumour cells progression in vivo and are clinically associated with poorer progression-free disease intervals. Finally, both MEOX2 and GLI1 were detected to be epigenetically involved in EGFR expression by reducing both repressive markers polycomb-EZH2 and histone H3K27me3, but, particularly, increasing an activated histone profile H3K27Ac/H3K4me3 at EGFR-gene enhancer-promoter sequences that probably representing a novel EGFR-TKI-based therapy resistance mechanism. ConclusionMEOX2/GLI1 promote resistance to cisplatin and EGFR-TKI-based therapy in lung cancer cells, modulating EGFR/AKT/ERK signalling pathway activation, as well as inducing an aberrant epigenetic modulation of the EGFR-gene expression in human lung cancer.

Fibroblast growth factor receptor 1 gene amplification and protein expression in human lung cancer.

BackgroundTargeting fibroblast growth factor receptor 1 (FGFR1) is a potential treatment for squamous cell lung cancer (SQCLC). So far, treatment decision in clinical studies is based on gene amplification. However, only a minority of patients have shown durable response. Furthermore, former studies have revealed contrasting results regarding the impact of FGFR1 amplification and expression on patient's prognosis.AimsHere, we analyzed prevalence and correlation of FGFR1 gene amplification and protein expression in human lung cancer and their impact on overall survival.Materials & Methods FGFR1 gene amplification and protein expression were analyzed by fluorescence in situ hybridization and immunohistochemistry (IHC) in 208 SQCLC and 45 small cell lung cancers (SCLC). Furthermore, FGFR1 protein expression was analyzed in 121 pulmonary adenocarcinomas (ACs). Amplification and expression were correlated to each other, clinicopathological characteristics, and overall survival.Results FGFR1 was amplified in 23% of SQCLC and 8% of SCLC. Amplification was correlated to males (P = .027) but not to overall survival. Specificity of immunostaining was verified by cellular CRISPR/Cas9 FGFR1 knockout. FGFR1 was strongly expressed in 9% of SQCLC, 35% of AC, and 4% of SCLC. Expression was correlated to females (P = .0187) and to the absence of lymph node metastasis in SQCLC (P = .018) with no significant correlation to overall survival. Interestingly, no significant correlation between amplification and expression was detected.Discussion FGFR1 gene amplification does not seem to correlate to protein expression.ConclusionWe believe that patient selection for FGFR1 inhibitors in clinical studies should be reconsidered. Neither FGFR1 amplification nor expression influences patient's prognosis.

Role of DNA methylation regulation of miR-130b expression in human lung cancer using bioinformatics analysis

ABSTRACTMicroRNAs (miRNAs) are involved in various crucial biological processes including regulation of cell differentiation, proliferation, and migration, and are closely associated with tumor development. This study aimed to investigate miR-130b expression levels in lung cancer patient tissues. Two Gene Expression Omnibus (GEO) databases, including GSE48414 and GSE74190, and two The Cancer Genome Atlas (TCGA) databases including TCGA LUAD and TCGA LUSC, were accessed to obtain information for differential expression analysis and clinical-pathological correlation analysis. The results showed that miR-130b expression levels were significantly increased in lung cancer compared to normal tissues. Data also demonstrated that confounding factors such as tumor clinical stages and tumor invasion depth markedly affected miR-130b expression levels in cancer patients. A total of 169 target genes modified by miR-130b expression were identified by using 4 online websites for target gene prediction. Further enrichment analysis indicated that these 169 target genes were significantly enriched in several cancer-related biological processes and signaling pathways, including wound healing, cell proliferation, Wnt signaling, Ras signaling, and mTOR signaling. It was also of interest to examine the seven sites on the promoter region of miR-130b encoding gene in lung cancer patients and then compare methylation at these loci with miR-130b expression. The correlation analysis between encoding gene methylation and miR-130b expression in TCGA datasets revealed that decreased methylation in the promoter region was significantly associated with elevated miR-130b expression. This phenomenon was markedly dependent upon smoking history and clinical-pathological features. In conclusion, data indicated alterations in the methylation of DNA promoter region of miR-130b encoding gene were associated with disturbances in miR-130b expression in lung cancer patients suggesting that the DNA methylation process and miR-130b expression may serve as biomarkers for detection of lung cancer.

Novel reciprocal interaction of lncRNA HOTAIR and miR‐214‐3p contribute to the solamargine‐inhibited PDPK1 gene expression in human lung cancer

Solamargine (SM) has been shown to have anti‐cancer properties. However, the underlying mechanism involved remains undetermined. We showed that SM inhibited the growth of non‐small cell lung cancer (NSCLC) cells, which was enhanced in cells with silencing of long non‐coding RNA (lncRNA) HOX transcript antisense RNA (HOTAIR), while it overcame by overexpression of HOTAIR. In addition, SM increased the expression of miR‐214‐3p and inhibited 3‐phosphoinositide‐dependent protein kinase‐1 (PDPK1) gene expression, which was strengthened by miR‐214‐3p mimics. Intriguingly, HOTAIR could directly bind to miR‐214‐3p and sequestered miR‐214‐3p from the target gene PDPK1. Intriguingly, overexpression of PDPK1 overcame the effects of SM on miR‐214‐3p expressions and neutralized the SM‐inhibited cell growth. Similar results were observed in vivo. In summary, our results showed that SM‐inhibited NSCLC cell growth through the reciprocal interaction between HOTAIR and miR‐214‐3p, which ultimately suppressed PDPK1 gene expression. HOTAIR effectively acted as a competing endogenous RNA (ceRNA) to stimulate the expression of target gene PDPK1. These complex interactions and feedback mechanisms contribute to the overall effect of SM. This unveils a novel molecular mechanism underlying the anti‐cancer effect of SM in human lung cancer.

Oct4 upregulates osteopontin via Egr1 and is associated with poor outcome in human lung cancer

BackgroundRoles of cancer stem cells and early growth response gene 1 (Egr1) in carcinogenesis have been extensively studied in lung cancer. However, the role of Egr1 in the metastasis of lung cancer remains undetermined, especially in regard to stem cell-related pathways.MethodsEgr1, osteopontin (OPN) and Oct4 expression in human lung cancer was determined by performing immunohistochemistry. Immunoblotting, ELISA, luciferase reporter assay, chromatin immunoprecipitation assay and RT-PCR were performed to validate the regulation of Oct4-Egr1-OPN axis. Moreover, the effect of Oct4-Egr1-OPN axis on lung cancer progression was evaluated by cell migration assay and mice study.ResultsWe detected Oct4, Egr1, and OPN expression in clinical specimens from 79 lung cancer patients, including 72 adenocarcinomas and 7 squamous cell carcinomas. High expression of Oct4, Egr1, and OPN accounted for 53, 51, and 57% of the patients, respectively. All of the three biomarkers were positively correlated in clinical human lung cancer. Patients with high expression of OPN were significantly associated with shorter disease-free survivals than those with low expression of OPN (p < 0.05). In lung cancer cells, Oct4 transactivated the Egr1 promoter and upregulated Egr1 expression. In a human lung cancer xenograft model, Oct4-overexpressing tumors expressed elevated levels of Egr1. Furthermore, overexpression of Oct4 in lung cancer cells increased the metastatic potential.ConclusionsEgr1 exerts a promoting effect on cancer metastasis in Oct4-overexpressing lung cancer. Thus, therapeutic strategies targeting the Oct4/Egr1/OPN axis may be further explored for the treatment of lung cancer, especially when lung cancer is refractory to conventional treatment due to cancer stem cells.

Nr5a2 promotes cancer stem cell properties and tumorigenesis in nonsmall cell lung cancer by regulating Nanog.

Lung cancer has the highest mortality rate due to late diagnosis and high incidence of metastasis. Cancer stem cells (CSCs) are a subgroup of cancer cells with self‐renewal capability similar to that of normal stem cells (NSCs). While CSCs may play an important role in cancer progression, mechanisms underlying CSC self‐renewal and the relationship between self‐renewal of the NSCs and CSCs remain elusive. The orphan nuclear receptor Nr5a2 is a transcriptional factor, and a regulator of stemness of embryonic stem cells and induced pluripotent stem cells. However, whether Nr5a2 regulates the self‐renewal of lung CSCs is unknown. Here, we showed the diagnostic and prognostic values of elevated Nr5a2 expression in human lung cancer. We generated the mouse LLC‐SD lung carcinoma CSC cellular model in which Nr5a2 expression was enhanced. Using the LLC‐SD model, through transient and stable siRNA interference of Nr5a2 expression, we provided convincing evidence for a regulatory role of Nr5a2 in the maintenance of lung CSC self‐renewal and stem cell properties in vitro. Further, using the syngeneic and orthotopic lung transplantation model, we elucidated augmented cancer biological properties associated with Nr5a2 promotion of LLC‐SD self‐renewal. More importantly, we revealed that Nr5a2’s regulatory role in promoting LLC‐SD self‐renewal is mediated by transcriptional activation of its direct target Nanog. Taken together, in this study, we have provided convincing evidence in vitro and in vivo demonstrating that Nr5a2 can induce lung CSC properties and promote tumorigenesis and progression through transcriptional up‐regulation of Nanog.

Histone deacetylase�5 promotes the proliferation and invasion of lung cancer cells

Histone deacetylase5 (HDAC5), as a member of the class IIa family of HDACs, is frequently dysregulated in human malignancies. However, little is known regarding the specific role of HDAC5 in lung cancer. We aimed to evaluate HDAC5 expression in human lung cancer and to determine the effects of HDAC5 on lung cancer cells. First, the expression levels of both HDAC5 protein and mRNA were evaluated in lung cancer tissues and cell lines by western blot analysis and RT‑qPCR, and the results suggested that HDAC5 was significantly upregulated in human lung cancer tissues and cell lines. To address the effects of HDAC5 on the biological behavior of human lung adenocarcinoma cells, we generated human lung cancer A549 cell lines in which HDAC5 was either overexpressed or depleted. The results indicated that overexpression of HDAC5 significantly promoted the proliferation and invasion, and inhibited the apoptosis of A549 cells. On the contrary, HDAC5 knockdown largely decreased the proliferation and invasion and enhanced the apoptosis of A549 cells. Furthermore, we demonstrated that HDAC5 overexpression promoted the expression of DLL4, Six1, Notch1 and Twist1 in A549 cells. Downregulation of HDAC5 caused a significant inhibition of the expression of DLL4, Six1, Notch1 and Twist1 in A549 cells. Taken together, our data demonstrated that HDAC5 displayed a significant upregulation in lung cancer, and elevated HDAC5 might be involved in the potentiation of proliferation and invasion of lung cancer cells, as well as the inhibition of lung cancer cell apoptosis by the upregulation of DLL4, Six1, Notch1 and Twist1. The present study may provide an evidence for the potential application of HDAC5 inhibitors in the therapy of lung cancer.

Abstract 3803: Immune escape from NK cells and activated CD8 T cells by miR-183 repression of MICA/B expression in human lung cancer

Abstract Immune escape is a hallmark of cancer. In human lung cancer, we have identified a unique microRNA (miR)-based pathway employed by tumor cells to repress detection by immune cells via the NKG2D-MICA/B receptor-ligand system. MICA/B is readily induced by cell transformation and serves as a danger signal and ligand to alert NK and activated CD8+ T cells. However, immunohistochemical analysis indicated that human lung adenocarcinoma and squamous cell carcinoma specimens express little MICA/B while high levels of miR-183 were detected in both tumor types in a TCGA database. Human lung tumor cell lines confirmed the reverse relationship in expression of MICA/B and miR-183. Importantly, a miR-183 binding site was identified on the 3' untranslated region (UTR) of both MICA and MICB, suggesting its role in MICA/B regulation. Luciferase reporter constructs bearing the 3'UTR of MICA or MICB in 293 cells supported the function of miR-183 in repressing MICA/B expression. Additionally, anti-sense miR-183 transfection into H1355 or H1299 tumor cells caused the upregulation of MICA/B. Abundant miR-183 expression in tumor cells was traced to transforming growth factor-beta (TGFβ), as evidenced by anti-sense TGFβ transfection into H1355 or H1299 tumor cells, which subsequently lost miR-183 expression accompanied by MICA/B upregulation. Most significantly, anti-sense miR-183 transfected tumor cells became more sensitive to lysis by activated CD8+ T cells that express high levels of NKG2D. Thus, high miR-183 triggered by TGFβ expressed in lung tumor cells can target MICA/B expression to circumvent detection by NKG2D on immune cells. Citation Format: Nhan Tu, Thu Le Trinh, Sarah S. Donatelli, Melba M. Tejera, Danielle L. Gilvary, Jun-Min Zhou, Erika A. Egsioglu, Sheng Wei, Domenico Coppola, Julie Y. Djeu. Immune escape from NK cells and activated CD8 T cells by miR-183 repression of MICA/B expression in human lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3803.

Evidence against a role for jaagsiekte sheep retrovirus in human lung cancer

BackgroundJaagsiekte sheep retrovirus (JSRV) causes a contagious lung cancer in sheep and goats that can be transmitted by aerosols produced by infected animals. Virus entry into cells is initiated by binding of the viral envelope (Env) protein to a specific cell-surface receptor, Hyal2. Unlike almost all other retroviruses, the JSRV Env protein is also a potent oncoprotein and is responsible for lung cancer in animals. Of concern, Hyal2 is a functional receptor for JSRV in humans.ResultsWe show here that JSRV is fully capable of infecting human cells, as measured by its reverse transcription and persistence in the DNA of cultured human cells. Several studies have indicated a role for JSRV in human lung cancer while other studies dispute these results. To further investigate the role of JSRV in human lung cancer, we used highly-specific mouse monoclonal antibodies and a rabbit polyclonal antiserum against JSRV Env to test for JSRV expression in human lung cancer. JSRV Env expression was undetectable in lung cancers from 128 human subjects, including 73 cases of bronchioalveolar carcinoma (BAC; currently reclassified as lung invasive adenocarcinoma with a predominant lepidic component), a lung cancer with histology similar to that found in JSRV-infected sheep. The BAC samples included 8 JSRV DNA-positive samples from subjects residing in Sardinia, Italy, where sheep farming is prevalent and JSRV is present. We also tested for neutralizing antibodies in sera from 138 Peruvians living in an area where sheep farming is prevalent and JSRV is present, 24 of whom were directly exposed to sheep, and found none.ConclusionsWe conclude that while JSRV can infect human cells, JSRV plays little if any role in human lung cancer.

P2.01-072 Clinical Associations of MUC1 Expression in Human Lung Cancer and Precancerous Lesions

P2.01-072 Clinical Associations of MUC1 Expression in Human Lung Cancer and Precancerous Lesions

Hippo pathway effector YAP inhibition restores the sensitivity of EGFR-TKI in lung adenocarcinoma having primary or acquired EGFR-TKI resistance

The efficacy of EGFR-tyrosine kinase inhibitors (TKIs) is significantly limited by various resistance mechanisms to those drugs. The resistance to EGFR-TKI is largely divided by two classes; acquired resistance after EGFR-TKI treatment, and primary resistance marked by cancer cell's dependence on other oncogene, such as KRAS. YAP has emerged as critical oncogene in conferring drug resistance against targeted therapy. In this study, we evaluated the role of YAP in primary and acquired EGFR-TKI resistance using gefitinib-resistant A549 and PC9 cells and their parental cell lines. Our study revealed that EGFR-TKI resistance is associated with enhanced YAP activity. Notably, YAP activation was independent of the Hippo pathway. We confirmed that AXL is a downstream target of YAP that confers EGFR-TKI resistance. And our results showed that YAP can induce ERK activation in lung adenocarcinoma. The combination of YAP inhibition with EGFR-TKI overcomes primary and acquired EGFR-TKI resistance. We also found increased YAP expression in human lung cancer after acquiring EGFR-TKI resistance. Collectively, we suggest a novel EGFR-TKI resistance mechanism involving YAP activation and suggest targeting YAP and EGFR simultaneously may be a breakthrough treatment of primary and acquired EGFR-TKI resistant lung cancer.

The histone demethylase PHF8 is an oncogenic protein in human non-small cell lung cancer

PHF8 is a JmjC domain-containing protein and erases repressive histone marks including H4K20me1 and H3K9me1/2. It binds to H3K4me3, an active histone mark usually located at transcription start sites (TSSs), through its plant homeo-domain, and is thus recruited and enriched in gene promoters. PHF8 is involved in the development of several types of cancer, including leukemia, prostate cancer, and esophageal squamous cell carcinoma. Herein we report that PHF8 is an oncogenic protein in human non-small cell lung cancer (NSCLC). PHF8 is up-regulated in human NSCLC tissues, and high PHF8 expression predicts poor survival. Our in vitro and in vivo evidence demonstrate that PHF8 regulates lung cancer cell proliferation and cellular transformation. We found that PHF8 knockdown induces DNA damage and apoptosis in lung cancer cells. PHF8 promotes miR-21 expression in human lung cancer, and miR-21 knockdown blocks the effects of PHF8 on proliferation and apoptosis of lung cancer cells. In summary, PHF8 promotes lung cancer cell growth and survival by regulating miR-21.

Design, synthesis, and validation of Axl-targeted monoclonal antibody probe for microPET imaging in human lung cancer xenograft.

Accumulating experimental evidence indicates that overexpression of the oncogenic receptor tyrosine kinase, Axl, plays a key role in the tumorigenesis and metastasis of various types of cancer. The objective of this study is to design a novel imaging probe based on the monoclonal antibody, h173, for microPET imaging of Axl expression in human lung cancer. A bifunctional chelator, DOTA, was conjugated to h173, followed by radiolabeling with 64Cu. The binding of DOTA-h173 to the Axl receptor was first evaluated by a cell uptake assay and flow cytometry analysis using human lung cancer cell lines. The probe 64Cu-DOTA-h173 was further evaluated by microPET imaging, and ex vivo histology studies in the Axl-positive A549 tumors. In vitro cellular study showed that Axl probe, 64Cu-DOTA-h173, was highly immuno-reactive with A549 cells. Western blot analysis confirmed that Axl is highly expressed in the A549 cell line. For microPET imaging, the A549 xenografts demonstrated a significantly higher 64Cu-DOTA-h173 uptake compared to the NCI-H249 xenograft (a negative control model). Furthermore, 64Cu-DOTA-h173 uptake in A549 is significantly higher than that of 64Cu-DOTA-hIgG. Immuno-fluorescence staining was consistent with the in vivo micro-PET imaging results. In conclusion, 64Cu-DOTA-h173 could be potentially used as a probe for noninvasive imaging of Axl expression, which could collect important information regarding tumor response to Axl-targeted therapeutic interventions.

A Reevaluation of CD22 Expression in Human Lung Cancer

CD22 is a transmembrane glycoprotein expressed by mature B cells. It inhibits signal transduction by the B-cell receptor and its coreceptor CD19. Recent reports indicate that most human lung cancer cells and cell lines express CD22, making it an important new therapeutic target for lung cancer. The objective of our studies was to independently validate these results with the goal of testing the efficacy of our CD22 immunotoxins on lung cancer cell lines. As determined by quantitative real-time PCR analysis, we found that levels of CD22 mRNA in a panel of human lung cancer cell lines were 200 to 60,000-fold lower than those observed in the human CD22(+) Burkitt lymphoma cells, Daudi. Using flow cytometry with a panel of CD22 monoclonal antibodies and Western blot analyses, we could not detect surface or intracellular expression of CD22 protein in a panel of lung cancer cell lines. In addition, the in vitro proliferation of the lung tumor cell lines was not affected by either CD22 antibodies or our highly potent anti-CD22 immunotoxin. In contrast, CD22(+) Daudi cells expressed high levels of CD22 mRNA and protein, and were sensitive to our CD22 immunotoxin. Importantly, primary non-small cell lung cancers from more than 250 patient specimens did not express detectable levels of CD22 protein as assessed by immunohistochemistry. We conclude that CD22 is not expressed at measurable levels on the surface of lung cancer cells, and that these cells cannot be killed by anti-CD22 immunotoxins.

Pulmonary CYP2A13 levels are associated with early occurrence of lung cancer—Its implication in mutagenesis of non-small cell lung carcinoma

CYP2A13, a human pulmonary specific cytochrome P450 enzyme, plays an important role in susceptibility to tobacco-specific nitrosamines (TSNAs)-induced lung cancer in humans. The pattern of CYP2A13 distribution in respiratory tract affects the susceptibility of the lung to carcinogens. CYP2A13 is expressed in the epithelium of trachea and bronchi; however its pattern of expression in human lung cancer remains largely unknown. This study aimed to determine the CYP2A13 expression in specimens from human non-small cell lung carcinomas (NSCLCs), i.e., adenocarcinoma and squamous carcinoma, by immunohistochemical (IHC) analysis and to identify the potential linkage between tumor CYP2A13 levels and some clinicopathological characteristics of NSCLC patients in Taiwan. The tumor CYP2A13 IHC staining signal was strong in 76% of the 112 study subjects. Study subjects (especially non-smoking or lung adenocarcinoma patients) with higher tumor CYP2A13 levels were younger. Multiple logistic regression analysis revealed that in younger subjects (age≤66) and heavy smokers (pack-years≥40), the odds ratio (OR) for positive tumor CYP2A13 staining was significantly higher than that for negative tumor CYP2A13 staining. Moreover, the association of EGFR gene mutations and positive tumor CYP2A13 staining was also revealed. In conclusion, these findings suggest the potential involvement of pulmonary CYP2A13 in the early occurrence of NSCLC as well as in the development of EGFR gene mutations.

MiRNA expression in human lung cancer and fetal lung: a comparative study

Background Many molecular systems involved in controlling development are also implicated in malignant transformation and are associated with poorer survival outcomes in cancer patients. In fact, lung tumours with similar gene expression profiles to fetal lung cells are associated with aggressive phenotypes of the disease. As targeting fetal developmental pathways selectively reactivated in cancer cells would presumably spare normal adult cells from toxicity, these pathways are considered ideal therapeutic targets for cancer treatment. Therefore, a better understanding of the interplay between fetal lung development and lung cancer on the level of individual miRNAs will provide new insights for translational research. In this study we applied sequencing technology to identify miRNAs with similar expression patterns between fetal lung and lung tumours.

Selection of optimal internal references for miRNA expression in human lung cancer using real-time quantitative RT-PCR

小RNA(microRNA,miRNA)是一类体积微小的内源性非编码RNA,可其通过翻译后水平调节靶基因的表达.miRNA在肺脏的发育过程中发挥多种作用,其异常表达很可能是肺癌发生的原因之一,且在肺癌的发生与发展过程中呈不同的表达水平,可作为新型的临床生物标志物用于肺癌的诊断、预后评估及指导治疗方案的选择等[1-3].即时定量逆转录聚合酶链反应(quantitative reverse transcription-PCR,RT-qPCR)技术目前已广泛应用于miRNA的表达分析[1-2]。

Survivin expression in human lung cancer and the influence of its downregulation on the biological behavior of human lung cancer cells

The aim of the present study was to detect the expression of survivin in human lung cancer and to investigate the influence of its downregulation on the biological behavior of A549 lung cancer cells. The high expression of survivin in human lung cancer was verified by immunohistochemistry. Survivin small interfering RNA (siRNA) and unrelated sequence were synthesized and the siRNA lentiviral vector was constructed. The vector was transfected into A549 lung cancer cells, in which the clone with stable expression was screened out. We blocked the expression of survivin mRNA and protein by RNA interference (RNAi) technique. The downregulation of survivin mRNA and protein expression was confirmed by real-time quantitative PCR and western blotting. The proliferative activity and growth rate of A549 cells were determined by colony formation assay and mononuclear cell direct cytotoxicity assay (MTT assay). The reconstituted basement membrane (RBM) penetrating capacity was determined by cell invasion assay. The cell movement and migratory capacity were detected by wound-healing repair assay. The results showed that the sequence-specific siRNA significantly downregulated the expression of survivin at both the mRNA and protein levels. Downregulation of survivin expression dramatically decreased the invasive and metastatic capacities of the cells, suppressed the proliferation, decelerated the rate of growth, reduced the number of clones on soft agar and decreased the capacity of RBM penetration and migration. In conclusion, survivin, which plays an important role in carcinogenesis and development of lung cancer, can be effectively downregulated using the RNAi technique.