Fragile Histidine Triad Gene Inactivation in Lung Cancer

Treatment of lung cancer by acupuncture combined with medicine based on pathophysiological mechanism: A review

Lung cancer is one of the most frequently diagnosed cancers in the world. There are an estimated 2.2 million new cases and 1.79 million deaths each year. Over the past 2 decades, our understanding of disease biology, the use of predictive biomarkers, and improvements in therapeutic approaches have made significant progress and transformed the outcomes of many patients. Treatment is determined by the subtype and stage of the cancer; however, the effect of personalized treatment remains unsatisfactory. The use of Chinese medicines has attracted increasing attention worldwide. Chinese medicine treatment of lung cancer has few side effects, which can effectively prolong the survival expectation of patients and improve their quality of life, and has attracted increasing attention. Based on the pathophysiological mechanism of lung cancer reported in modern medical research, this article explores the efficacy and safety of acupuncture combined with medicine in the treatment of lung cancer.

Combinations of grape seed procyanidin extract and milk thistle silymarin extract against lung cancer - The role of MiR-663a and FHIT

AIMS

Grape seed procyanidin extract (GSE), and milk thistle silymarin extract (MTE) contain structurally distinct polyphenols, and each agent has been shown to exert antineoplastic effects against lung cancer. We hypothesize that combinations of GSE and MTE will additively enhance their anticancer effects against lung cancer.

MATERIALS AND METHODS

The anti-proliferative effects of GSE, MTE and combinations were evaluated in lung neoplastic cell lines. A dose range finding (DRF) study to determine safety, bioavailability and bioactivity, followed by human lung cancer xenograft efficacy studies were conducted in female nude mice with once daily gavage of leucoselect phytosome (LP), a standardized GSE, and/or siliphos, a standardized MTE. The roles of tumor suppressors miR-663a and its predicted target FHIT in mediating the additive, anti-proliferative effecs of GSE/MTE were also assessed.

KEY FINDINGS

GSE with MTE additively inhibited lung preneoplastic and cancer cell proliferations. Mice tolerated all dosing regimens in the DRF study without signs of clinical toxicity nor histologic abnormalities in the lungs, livers and kidneys. Eight weeks of LP and siliphos additively inhibited lung tumor xenograft growth. Plasma GSE/metabolites and MTE/metabolites showed that the combinations did not decrease systemic bioavailabilities of each agent. GSE and MTE additively upregulated miR-663a and FHIT in lung cancer cell lines; transfection of antisense-miR-663a significantly abrogated the anti-proliferative effects of GSE/MTE, upregulation of FHIT mRNA and protein. LP and siliphos also additively increased miR-663a and FHIT protein in lung tumor xenografts.

SIGNIFICANCE

Our findings support clinical translations of combinations of GSE and MTE against lung cancer.

A Practical Electrochemical Nanotool for Facile Quantification of Amino Acids in Single Cell

Though significant advances are made in the arena of single-cell electroanalysis, quantification of intracellular amino acids of human cells remains unsolved. Exemplified by l-histidine (l-His), this issue is addressed by a practical electrochemical nanotool synergizing the highly accessible nanopipette with commercially available synthetic DNAzyme. The fabricated nanotools are screened before operation of a single-use manner, and the l-His-provoked cleavage of the DNA molecules can be sensibly transduced by the ionic current rectification response, the intrinsic property of nanopipette governed by its interior surface charges. Regional distribution of cytosolic l-His level in human cells is electrochemically quantified for the first time, and time-dependent drug treatment effects are further revealed. This work unveils the possibility of electrochemistry for quantification of cytosolic amino acids of a spatial- and time-based manner and ultimately enables a better understanding of amino acid-involved events in living cells.

MHC heterogeneity and response of metastases to immunotherapy

In recent years, immunotherapy has proven to be an effective treatment against cancer. Cytotoxic T lymphocytes perform an important role in this anti-tumor immune response, recognizing cancer cells as foreign, through the presentation of tumor antigens by MHC class I molecules. However, tumors and metastases develop escape mechanisms for evading this immunosurveillance and may lose the expression of these polymorphic molecules to become invisible to cytotoxic T lymphocytes. In other situations, they may maintain MHC class I expression and promote immunosuppression of cytotoxic T lymphocytes. Therefore, the analysis of the expression of MHC class I molecules in tumors and metastases is important to elucidate these escape mechanisms. Moreover, it is necessary to determine the molecular mechanisms involved in these alterations to reverse them and recover the expression of MHC class I molecules on tumor cells. This review discusses the role and regulation of MHC class I expression in tumor progression. We focus on altered MHC class I phenotypes present in tumors and metastases, as well as the molecular mechanisms responsible for MHC-I alterations, emphasizing the mechanisms of recovery of the MHC class I molecules expression on cancer cells. The individualized study of the HLA class I phenotype of the tumor and the metastases of each patient will allow choosing the most appropriate immunotherapy treatment based on a personalized medicine.

Targeting DNA methyltransferases in non-small-cell lung cancer

Despite the advances in treatment using chemotherapy or targeted therapies, due to static survival rates, non-small cell lung cancer (NSCLC) is the major cause of cancer-related deaths worldwide. Epigenetic-based therapies have been developed for NSCLC by targeting DNA methyltransferases (DNMTs) and histone-modifying enzymes. However, treatment using single epigenetic agents on solid tumours has been inadequate; whereas, treatment with a combination of DNMTs inhibitors with chemotherapy and immunotherapy has shown great promise. Dietary sources of phytochemicals could also inhibit DNMTs and cancer stem cells, representing a novel and promising way to prevent and treat cancer. Herein, we will discuss the different DNMTs, DNA methylation profiling in NSCLC as well as current demethylating agents in ongoing clinical trials. Therefore, providing a concise overview of future developments in the field of epigenetic therapy in NSCLC.

Possible Oncogenic Viruses Associated with Lung Cancer

Lung cancer is the most common cause of cancer death worldwide. Tobacco smoking is the most predominant etiology for lung cancer. However, only a small percentage of heavy smokers develop lung cancer, which suggests that other cofactors are required for lung carcinogenesis. Viruses have been central to modern cancer research and provide profound insights into cancer causes. Nevertheless, the role of virus in lung cancer is still unclear. In this article, we reviewed the possible oncogenic viruses associated with lung cancer.

Restoration of MHC-I on Tumor Cells by Fhit Transfection Promotes Immune Rejection and Acts as an Individualized Immunotherapeutic Vaccine

The capacity of cytotoxic-T lymphocytes to recognize and destroy tumor cells depends on the surface expression by tumor cells of MHC class I molecules loaded with tumor antigen peptides. Loss of MHC-I expression is the most frequent mechanism by which tumor cells evade the immune response. The restoration of MHC-I expression in cancer cells is crucial to enhance their immune destruction, especially in response to cancer immunotherapy. Using mouse models, we recovered MHC-I expression in the MHC-I negative tumor cell lines and analyzed their oncological and immunological profile. Fhit gene transfection induces the restoration of MHC-I expression in highly oncogenic MHC-I-negative murine tumor cell lines and genes of the IFN-γ transduction signal pathway are involved. Fhit-transfected tumor cells proved highly immunogenic, being rejected by a T lymphocyte-mediated immune response. Strikingly, this immune rejection was more frequent in females than in males. The immune response generated protected hosts against the tumor growth of non-transfected cells and against other tumor cells in our murine tumor model. Finally, we also observed a direct correlation between FHIT expression and HLA-I surface expression in human breast tumors. Recovery of Fhit expression on MHC class I negative tumor cells may be a useful immunotherapeutic strategy and may even act as an individualized immunotherapeutic vaccine.

The Current Understanding Of Asbestos-Induced Epigenetic Changes Associated With Lung Cancer

Asbestos is a naturally occurring mineral consisting of extremely fine fibres that can become trapped in the lungs after inhalation. Occupational and environmental exposures to asbestos are linked to development of lung cancer and malignant mesothelioma, a cancer of the lining surrounding the lung. This review discusses the factors that are making asbestos-induced lung cancer a continuing problem, including the extensive historic use of asbestos and decades long latency between exposure and disease development. Genomic mutations of DNA nucleotides and gene rearrangements driving lung cancer are well-studied, with biomarkers and targeted therapies already in clinical use for some of these mutations. The genes involved in these mutation biomarkers and targeted therapies are also involved in epigenetic mechanisms and are discussed in this review as it is hoped that identification of epigenetic aberrations in these genes will enable the same gene biomarkers and targeted therapies to be used. Currently, understanding of how asbestos fibres trapped in the lungs leads to epigenetic changes and lung cancer is incomplete. It has been shown that oxidoreduction reactions on fibre surfaces generate reactive oxygen species (ROS) which in turn damage DNA, leading to genetic and epigenetic alterations that reduce the activity of tumour suppressor genes. Epigenetic DNA methylation changes associated with lung cancer are summarised in this review, and some of these changes will be due to asbestos exposure. So far, little research has been carried out to separate the asbestos driven epigenetic changes from those due to non-asbestos causes of lung cancer. Asbestos-associated lung cancers exhibit less methylation variability than lung cancers in general, and in a large proportion of samples variability has been found to be restricted to promoter regions. Epigenetic aberrations in cancer are proving to be promising biomarkers for diagnosing cancers. It is hoped that further understanding of epigenetic changes in lung cancer can result in useful asbestos-associated lung cancer biomarkers to guide treatment. Research is ongoing into the detection of lung cancer epigenetic alterations using non-invasive samples of blood and sputum. These efforts hold the promise of non-invasive cancer diagnosis in the future. Efforts to reverse epigenetic aberrations in lung cancer by epigenetic therapies are ongoing but have not yet yielded success.

Bright Yellow Fluorescent Carbon Dots as a Multifunctional Sensing Platform for the Label-Free Detection of Fluoroquinolones and Histidine

Owing to their diverse properties, fluorescent carbon dots (CDs) have attracted more attention and present enormous potential in development of sensors, bioimaging, drug delivery, microfluidics, photodynamic therapy, light emitting diode, and so forth. Herein, a multifunctional sensing platform based on bright yellow fluorescent CDs (Y-CDs) was designed for the label-free detection of fluoroquinolones (FQs) and histidine (His). The Y-CDs with superior optical and biological merits including high chemical stability, good biocompatibility, and low cytotoxicity were simply synthesized via one-step hydrothermal treatment of o-phenylenediamine ( o-PD) and 4-aminobutyric acid (GABA). The Y-CDs can be utilized to directly monitor the amount of FQs based on fluorescence static quenching owing to the specific interaction between FQs and Y-CDs. Then, the fluorescence of this system can be effectively recovered upon addition of His. The multifunctional sensing platform exhibited high sensitivity and selectivity toward three kinds of FQs and His with low detection limits of 17-67 and 35 nM, respectively. Benefiting from these outstanding characters, the Y-CDs were successfully employed for trace detection of FQs in real samples such as antibiotic tablets and milk products. Furthermore, the probe was also extended to cellular imaging. All of the above prove that this multifunctional sensing platform presents great prospect in multiple applications such as biosensing, biomedicine, disease diagnosis, and environmental monitoring.

A novel label-free colorimetric detection of l-histidine using Cu2+-modulated G-quadruplex-based DNAzymes

We proposed a colorimetric method for l-histidine detection based on Cu²⁺-mediated DNAzyme and G-quadruplex-hemin complex catalyzed oxidation of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS). In this system, after the addition of l-histidine, the formation of G-quadruplex-hemin complex will be disturbed, thus the colorimetric signal intensity conversely corresponds to the concentration of histidine. In this assay, a lower detection limit of l-histidine (50 nM) is addressed comparing to previously reported colorimetric methods. The cost is extremely low as the proposed design is both label-free and enzyme-free. All the more vitally, the colorimetric detection procedure is substantially straightforward with no further modification processes. By and large, the sensor can provide a promising plan for the detection of l-histidine.

Epigenomic profiling of non-small cell lung cancer xenografts uncover LRP12 DNA methylation as predictive biomarker for carboplatin resistance

Background

Non-small cell lung cancer (NSCLC) is the most common cause of cancer-related deaths worldwide and is primarily treated with radiation, surgery, and platinum-based drugs like cisplatin and carboplatin. The major challenge in the treatment of NSCLC patients is intrinsic or acquired resistance to chemotherapy. Molecular markers predicting the outcome of the patients are urgently needed.

Methods

Here, we employed patient-derived xenografts (PDXs) to detect predictive methylation biomarkers for platin-based therapies. We used MeDIP-Seq to generate genome-wide DNA methylation profiles of 22 PDXs, their parental primary NSCLC, and their corresponding normal tissues and complemented the data with gene expression analyses of the same tissues. Candidate biomarkers were validated with quantitative methylation-specific PCRs (qMSP) in an independent cohort.

Results

Comprehensive analyses revealed that differential methylation patterns are highly similar, enriched in PDXs and lung tumor-specific when comparing differences in methylation between PDXs versus primary NSCLC. We identified a set of 40 candidate regions with methylation correlated to carboplatin response and corresponding inverse gene expression pattern even before therapy. This analysis led to the identification of a promoter CpG island methylation of LDL receptor-related protein 12 (LRP12) associated with increased resistance to carboplatin. Validation in an independent patient cohort (n = 35) confirmed that LRP12 methylation status is predictive for therapeutic response of NSCLC patients to platin therapy with a sensitivity of 80% and a specificity of 84% (p < 0.01). Similarly, we find a shorter survival time for patients with LRP12 hypermethylation in the TCGA data set for NSCLC (lung adenocarcinoma).

Conclusions

Using an epigenome-wide sequencing approach, we find differential methylation patterns from primary lung cancer and PDX-derived cancers to be very similar, albeit with a lower degree of differential methylation in primary tumors. We identify LRP12 DNA methylation as a powerful predictive marker for carboplatin resistance. These findings outline a platform for the identification of epigenetic therapy resistance biomarkers based on PDX NSCLC models.

Electronic supplementary material

The online version of this article (10.1186/s13073-018-0562-1) contains supplementary material, which is available to authorized users.

Quantitative assessment of the diagnostic role of FHIT promoter methylation in non-small cell lung cancer

Aberrant methylation of CpG islands acquired in promoter regions plays an important role in carcinogenesis. Accumulated evidence demonstrates FHIT gene promoter hyper-methylation is involved in non-small cell lung cancer (NSCLC). To test the diagnostic ability of FHIT methylation status on NSCLC, thirteen studies, including 2,119 samples were included in our meta-analysis. Simultaneously, four independent DNA methylation datasets from TCGA and GEO database were analyzed for validation. The pooled odds ratio of FHIT promoter methylation in cancer samples was 3.43 (95% CI: 1.85 to 6.36) compared with that in controls. In subgroup analysis, significant difference of FHIT gene promoter methylation status in NSCLC and controls was found in Asians but not in Caucasian population. In validation stage, 950 Caucasian samples, including 126 paired samples from TCGA, 568 cancer tissues and 256 normal controls from GEO database were analyzed, and all 8 CpG sites near the promoter region of FHIT gene were not significantly differentially methylated. Thus the diagnostic role of FHIT gene in the lung cancer may be relatively limited in the Caucasian population but useful in the Asians.

Cu2+ modulated nitrogen-doped grapheme quantum dots as a turn-off/on fluorescence sensor for the selective detection of histidine in biological fluid

A highly sensitive sensor for detection of histidine (His) based on the nitrogen-doped graphene quantum dots (N-GQDs)-Cu²⁺ system has been designed. The N-GQDs were synthesized by one-step hydrothermal approach according to previous report. The fluorescence of N-GQDs can be effectively quenched by Cu²⁺ due to the binding between Cu²⁺ and functional groups on the surface of N-GQDs. The high affinity of His to Cu²⁺ enables Cu²⁺ to be dissociated from the surface of N-GQDs and recovering the fluorescence. The sensor displayed a sensitive response to His in the concentration range of 0-35μmolL^-1, with a detection limit of 72.2nmolL^-1. The proposed method is successfully applied to detect His in samples with a recovery range of 96-102%.

Lung cancer epigenetics: From knowledge to applications

Lung cancer is the leading cause of cancer-related mortality worldwide. Advances in our understanding of the genomics of lung cancer have led to substantial progress in the treatment of specific molecular subsets. Immunotherapy also emerges as a major breakthrough in lung cancer treatment. However, challenges remain as a consensual approach for early lung cancer detection remains elusive while primary or secondary drug resistance eventually leads to treatment failure in all patients with advanced disease. Furthermore, a large portion of patients are still treated with conventional chemotherapy that is only modestly effective. The last two decades have seen exponential developments in the epigenetic understanding of lung cancer. Epigenetic alterations in DNA methylation, non-coding RNA expression, chromatin modeling and post transcriptional regulators are key events in each step of lung cancer pathogenesis. Here, we review the central role epigenetic disruptions play in lung cancer carcinogenesis and the acquisition of cancerous phenotype and aggressive behavior as well as in the resistance to therapy. Epigenetic disruptions could represent reliable biomarkers for lung cancer risk assessment, early diagnosis, prognosis stratification, molecular classification and prediction of treatment efficacy. The therapeutic potential of epigenetics targeted drugs in combination with chemotherapy, targeted therapy and/or immunotherapy is currently being intensively investigated. We suggest that integration of tissue-derived or circulating epigenetic biomarkers and epidrugs in clinical trial design will translate epigenetic knowledge of lung cancer into the clinic and improve lung cancer patient outcomes.

Association of FHIT expression and FHIT gene hypermethylation with liver cancer risk: a PRISMA-compliant meta-analysis

Background

There have been suggestions that fragile histidine triad protein (FHIT) expression and FHIT gene hypermethylation were crucial to the pathogenesis of liver cancer. However, the conclusions remained unclear because of small sample size, disease subtype, and different detection techniques. Therefore, we performed a meta-analysis to estimate the associations of FHIT expression and FHIT gene hypermethylation with liver cancer pathogenesis.

Methods

Studies that were published in electronic databases, such as PubMed, Web of Knowledge, China National Knowledge Infrastructure (CNKI), VIP, and WanFang, were retrieved and selected for the meta-analysis. Relative risk (RR) and 95% confidence interval (CI) were calculated to determine the correlations of FHIT expression and FHIT gene hyper-methylation with liver cancer pathogenesis with Stata 12.0 software.

Results

A total of 17 papers that evaluated the associations of FHIT expression (14 articles) and FHIT gene methylation (3 articles) with liver cancer pathogenesis were included in this meta-analysis. In the overall analysis, the pooled relative risk was 1.93 (95% CI =1.72–2.17), which indicated a significant association between FHIT low expression and liver cancer risk. According to the results of clinical information, there were significant associations of FHIT expression with TNM-stage (RR =2.13, 95% CI =1.72–2.64), tumor size (RR =1.67, 95% CI =1.36–2.05), and merger of cirrhosis (RR =1.34, 95% CI =1.06–1.69) of liver cancer in the Chinese population. In addition, the FHIT gene hypermethylation was significantly associated with the risk of liver cancer (RR =1.45, 95% CI =1.08–1.93).

Conclusion

The FHIT expression and hypermethylation of FHIT gene were significantly associated with the risk of liver cancer, especially in the Chinese population. Furthermore, the results indicated significant associations between FHIT low expression and TNM-stage, tumor size, and merging of cirrhosis of liver cancer in the Chinese population.

New panel of microsatellite alterations detectable in the EBC for lung cancer prognosis

Our research group demonstrated, in a precedent study, the prognostic power of the 3p microsatellites alterations (MAs) detectable in exhaled breath condensate (EBC) in NSCLC patients. The analysis of genetic markers in the EBC might have precious clinical and economic consequences when inserted in diagnostic and follow up programs for lung cancer.

The aim of this study was to evaluate the prognostic value of a new panel of MAs in the EBC of patients with NSCLC.

We enrolled 45 NSCLC patients during a period of 36 months and the follow-up period was 156 weeks. We analyzed MAs for eight markers in EBC samples: D3S2338, D3S1266, D3S1300, D3S1304, D3S1289, D5S2094, D3S1313, and AFMa305ye1.

Our study showed that the presence of more than 2 simultaneous MAs reduces outcome in NSCLC patients. The new panel of eight microsatellites markers proposed in EBC samples could have a potential clinical role in assessing survival in lung cancer patients.

Regulatory roles of epigenetic modulators, modifiers and mediators in lung cancer

Lung cancer as the leading cause of cancer-related deaths can be initiated and progressed by the interaction between dynamically genetic and epigenetic elements, although mechanisms mediating lung cancer development and progression remain unclear. Tumor progenitor genes may contribute to lung carcinogenesis and cancer progression, are epigenetically disrupted at the early stages of malignancies even before mutations, and alter cell differentiation throughout tumor evolution. The present review explores potential roles and mechanisms of epigenetic modulators, modifiers and mediators in the development of lung cancer. We also overviewed potential mechanisms by which epigenetic modulators, modifiers and mediators control and regulate 3D nuclear architectures, and discussed translational efforts to epigenetic modifications for treatment of lung cancer. Deep understanding of epigenetic modulators, modifiers and mediators will benefit the discovery and development of new diagnostics and therapies for lung cancer.

The clinicopathological significance and ethnic difference of FHIT hypermethylation in non-small-cell lung carcinoma: a meta-analysis and literature review

Emerging evidence indicates that FHIT is a candidate tumor suppressor in many types of tumors including non-small-cell lung carcinoma (NSCLC). However, the prognostic value and correlation between FHIT hypermethylation and clinicopathological characteristics of NSCLC remains unclear. In this report, we performed a meta-analysis to evaluate the effects of FHIT hypermethylation on the incidence of NSCLC and clinicopathological characteristics of human NSCLC patients. Final analysis of 1,801 NSCLC patients from 18 eligible studies was performed. FHIT hypermethylation was found to be significantly higher in NSCLC than in normal lung tissue. The pooled odds ratio (OR) from ten studies included 819 NSCLC and 792 normal lung tissues (OR =7.51, 95% confidence interval [CI] =2.98-18.91, P<0.0001). Subgroup analysis based on ethnicity implied that FHIT hypermethylation level was higher in NSCLC tissues than in normal tissues in both Caucasians (P=0.02) and Asians (P<0.0001), indicating that the difference in Asians was much more significant. FHIT hypermethylation was also correlated with sex status, smoking status, as well as pathological types. In addition, patients with FHIT hypermethylation had a lower survival rate than those without (hazard ratio =1.73, 95% CI =1.10-2.71, P=0.02). The results of this meta-analysis suggest that FHIT hypermethylation is associated with an increased risk and poor survival in NSCLC patients. FHIT hypermethylation, which induces the inactivation of FHIT gene, plays an important role in the carcinogenesis and clinical outcome and may serve as a potential diagnostic marker and drug target of NSCLC.

The clinicopathological significance of FHIT hypermethylation in non-small cell lung cancer, a meta-analysis and literature review

Emerging evidence indicates that FHIT is a candidate tumor suppressor in non-small cell lung cancer (NSCLC). However, the correlation between FHIT hypermethylation and clinicopathological characteristics of NSCLC remains unclear. Thus, we conducted a meta-analysis to quantitatively evaluate the effects of FHIT hypermethylation on the incidence of NSCLC and clinicopathological characteristics. Final analysis of 1717 NSCLC patients from 16 eligible studies was performed. FHIT hypermethylation was found to be significantly higher in NSCLC than in normal lung tissue, the pooled OR from 8 studies including 735 NSCLC and 708 normal lung tissue, OR = 5.45, 95% CI = 2.15-13.79, p = 0.0003. FHIT hypermethylation was also correlated with sex status, smoking status, as well as pathological types. We did not find that FHIT hypermethylation was correlated with the differentiated types or clinical stages in NSCLC patients. However, patients with FHIT hypermethylation had a lower survival rate than those without, HR = 1.73, 95% CI = 1.10-2.71, p = 0.02. The results of this meta-analysis suggest that FHIT hypermethylation is associated with an increased risk and worsen survival in NSCLC patients. FHIT hypermethylation, which induces the inactivation of FHIT gene, plays an important role in the carcinogenesis and clinical outcome and may serve as a potential drug target of NSCLC.

A novel glutathione-stabilized silver–gold nano-alloy/Cu2+ combination as a fluorescent switch probe for l-histidine

This paper reports the synthesis of glutathione-stabilized silver–gold nano-alloys and their use as a fluorescent switch probe for the detection of l-histidine.

Epigenetics of lung cancer

Lung cancer is the leading cause of cancer-related mortality in the United States. Epigenetic alterations, including DNA methylation, histone modifications, and noncoding RNA expression, have been reported widely in the literature to play a major role in the genesis of lung cancer. The goal of this review is to summarize the common epigenetic changes associated with lung cancer to give some clarity to its etiology, and to provide an overview of the potential translational applications of these changes, including applications for early detection, diagnosis, prognostication, and therapeutics.

Detection of FHIT and p16 mRNA deletion in biopsy specimens obtained by bronchoscopy for the diagnosis of lung cancer

The purpose of this study was to investigate the diagnostic value of the deletion of fragile histidine triad (FHIT) and p16INK4a (p16) mRNA in biopsies obtained by bronchoscopy. Biopsies were analyzed using RT-PCR in 52 patients with lung cancer and 19 patients with benign lung disease. The results showed that the detection rates of FHIT and p16 gene transcript deletion were significantly higher in lung cancer patients than in patients with benign lung disease (65.4% versus 10.5%, p=0.001 and 59.6% versus 5.3%, p<0.001, respectively). The sensitivities for detecting FHIT and p16 transcript deletion in biopsies were 65.4% and 59.6% (combined 80.8%), respectively, which were markedly better than those of histology and cytology (42.3% and 34.6%, respectively; combined 57.7%). In 22 lung cancer patients with negative histology and cytology at initial bronchoscopy, FHIT and p16 mRNA loss was detected in 40.9% (9/22) and 36.4% (8/22) cases, respectively. FHIT mRNA loss was associated with smoking status in lung cancer patients. In conclusion, deletion of FHIT and p16 mRNA can be identified in biopsies obtained during bronchoscopic procedures. FHIT and p16 mRNA deletion can be used as biomarkers in the clinical diagnosis of lung cancer and may serve as adjuncts to histology and cytology in lung cancer diagnosis.

Lung cancer epigenetics: emerging biomarkers

Lung cancer is the leading cause of cancer-related deaths worldwide, and the 5-year survival rate is still very poor due to the scarcity of effective tools for early detection. The discovery of highly sensitive and specific biomarkers highlighting pathological changes early enough to allow clinical intervention is therefore of great importance. In the last decade, epigenetics and particularly research on DNA methylation have provided important information towards a better understanding of lung cancer pathogenesis. Novel and promising molecular biomarkers for diagnosis and prognosis of lung cancer are continuously emerging in this area, requiring further evaluation. This process includes extensive validation in prospective clinical trials before they can be routinely used in a clinical setting. This review summarizes the evidence on epigenetic biomarkers for lung cancer, focusing on DNA methylation.

DNA methylation profiles at precancerous stages associated with recurrence of lung adenocarcinoma

The aim of this study was to clarify the significance of DNA methylation alterations at precancerous stages of lung adenocarcinoma. Using single-CpG resolution Infinium array, genome-wide DNA methylation analysis was performed in 36 samples of normal lung tissue obtained from patients without any primary lung tumor, 145 samples of non-cancerous lung tissue (N) obtained from patients with lung adenocarcinomas, and 145 samples of tumorous tissue (T). Stepwise progression of DNA methylation alterations from normal lung tissue to non-cancerous lung tissue obtained from patients with lung adenocarcinomas, and then tumorous tissue samples, was observed at 3,270 CpG sites, suggesting that non-cancerous lung tissue obtained from patients with lung adenocarcinomas was at precancerous stages with DNA methylation alterations. At CpG sites of 2,083 genes, DNA methylation status in samples of non-cancerous lung tissue obtained from patients with lung adenocarcinomas was significantly correlated with recurrence after establishment of lung adenocarcinomas. Among such recurrence-related genes, 28 genes are normally unmethylated (average β-values based on Infinium assay in normal lung tissue samples was less than 0.2) and their DNA hypermethylation at precancerous stages was strengthened during progression to lung adenocarcinomas (Δβ(T-N)>0.1). Among these 28 genes, we focused on 6 for which implications in transcription regulation, apoptosis or cell adhesion had been reported. DNA hypermethylation of the ADCY5, EVX1, GFRA1, PDE9A, and TBX20 genes resulted in reduced mRNA expression in tumorous tissue samples. 5-Aza-2'-deoxycytidine treatment of lung cancer cell lines restored the mRNA expression levels of these 5 genes. Reduced mRNA expression in tumorous tissue samples was significantly correlated with tumor aggressiveness. These data suggest that DNA methylation alterations at precancerous stages determine tumor aggressiveness and outcome through silencing of specific genes.

Molecular diagnosis and prognostic significance of lymph node micrometastasis in patients with histologically node-negative non-small cell lung cancer

Lymph node metastasis is a major prognostic factor in resected non-small cell lung cancer (NSCLC). However, 30-40 % rate of recurrence after performing complete resection in node-negative patients suggests that their nodal staging is suboptimal. We aimed to evaluate the molecular diagnosis and prognostic significance of lymph node micrometastasis in patients with node-negative NSCLC. Primary tumor samples from 62 patients with resected stage I-IIB NSCLC were screened for fragile histidine triad (FHIT) and CDKN2A mRNA deletion using reverse transcriptase polymerase chain reaction (RT-PCR). The molecular alternations were found in tumors of 49 patients. A total of 269 lymph nodes from these 49 NSCLC patients with FHIT or/and CDKN2A deletion tumors were examined. Fifteen positive-control nodes and ten negative-control nodes were also analyzed for FHIT and CDKN2A mRNA deletion. Thirty-nine (22 %) and 22 (18 %) lymph nodes from the 49 patients with FHIT and CDKN2A mRNA deletion in primary tumor had FHIT and CDKN2A mRNA deletion, respectively. The types of FHIT and CDKN2A mRNA deletion in lymph nodes were identical with those in their primary tumors. By combination of two markers, 16 patients (32.7 %) were found to have nodal micrometastasis. Survival analysis showed that patients with nodal micrometastasis had reduced disease-free survival (P = 0.001) and overall survival (P = 0.002) rates. Multivariate analysis demonstrated that nodal micrometastasis was an independent predictor for worse prognosis. Thus, the detection of lymph node micrometastasis by FHIT and CDKN2A mRNA deletion RT-PCR will be helpful to predict the recurrence and prognosis of patients with completely resected stage I-IIB NSCLC.

The significance of epigenetic alterations in lung carcinogenesis

Lung cancer is recognized as a leading cause of cancer-related death worldwide and its frequency is still increasing. The prognosis in lung cancer is poor and limited by the difficulties of diagnosis at early stage of disease, when it is amenable to surgery treatment. Therefore, the advance in identification of lung cancer genetic and epigenetic markers with diagnostic and/or prognostic values becomes an important tool for future molecular oncology and personalized therapy. As in case of other tumors, aberrant epigenetic landscape has been documented also in lung cancer, both at early and late stage of carcinogenesis. Hypermethylation of specific genes, mainly tumor suppressor genes, as well as hypomethylation of oncogenes and retrotransposons, associated with histopathological subtypes of lung cancer, has been found. Epigenetic aberrations of histone proteins and, especially, the lower global levels of histone modifications have been associated with poorer clinical outcome in lung cancer. The recently discovered role of epigenetic modifications of microRNA expression in tumors has been also proven in lung carcinogenesis. The identified epigenetic events in lung cancer contribute to its specific epigenotype and correlated phenotypic features. So far, some of them have been suggested to be cancer biomarkers for early detection, disease monitoring, prognosis, and risk assessment. As epigenetic aberrations are reversible, their correction has emerged as a promising therapeutic target.

DNA methylation in promoter region as biomarkers in prostate cancer

The prostate gland is the most common site of cancer and the second leading cause of cancer death in American men. Recent emerging molecular biological technologies help us to know that epigenetic alterations such as DNA methylation within the regulatory (promoter) regions of genes are associated with transcriptional silencing in cancer. Promoter hypermethylation of critical pathway genes could be potential biomarkers and therapeutic targets for prostate cancer. In this chapter, we updated current information on methylated genes associated with the development and progression of prostate cancer. Over 40 genes have been investigated for methylation in promoter region in prostate cancer. These methylated genes are involved in critical pathways, such as DNA repair, metabolism, and invasion/metastasis. The role of hypermethylated genes in regulation of critical pathways in prostate cancer is discussed. These findings may provide new information of the pathogenesis, the exciting potential to be predictive and to provide personalized treatment of prostate cancer. Indeed, some epigenetic alterations in prostate tumors are being translated into clinical practice for therapeutic use.

[DNA methylation of tumor suppressor genes located on chromosome 3p in non-small cell lung cancer]

BACKGROUND AND OBJECTIVE

DNA methylation is one of the mechanisms of epigenetics. Allelic loss located on chromosome 3p happen frequently and early in non-small cell lung cancer (NSCLC). The aim of this study is to detect the promoter methylation status of tumor suppressor genes (TSGs) located on chromosome 3p in NSCLC and to evaluate its correlation with clinicopathological features.

METHODS

A total of 78 paired NSCLC specimens and their adjacent normal tissues were collected in the study. Promoter methylation status was determined by methylation-specific polymerase chain reaction (MSP). DLEC1 gene expression was determined by RT-PCR and immunohistochemistry.

RESULTS

Aberrant methylation frequency of DLEC1, RASSF1A, hMLH1, RARβ and FHIT genes detected in 78 NSCLC tissues were 41.03%, 39.74%, 30.77% and 16.67%, respectively, which were all significantly higher than that in adjacent normal tissues. However, FHIT gene was not detected methylation in both cancerous and non-cancerous tissues. DLEC1 hypermethylation was associated with advanced stage (P=0.011) and lymph metastasis (P=0.019), while RASSF1A, RARβ, hMLH1 and mean methylation index (MI) were not correlated with any clinicopathological parameters. Moreover, DLEC1 gene downregulation was detected in 56.41% (44/78) NSCLC tissues and correlated with promoter hypermethylation.

CONCLUSIONS

Frequent hypermethylation of TSGs located on chromosome 3p was a common event contributing to NSCLC pathogenesis and DLEC1 methylation was closely correlated with loss of expression.

FHIT gene and flanking region on chromosome 3p are subjected to extensive allelic loss in Egyptian breast cancer patients

The fragile histidine triad gene (FHIT) is a candidate tumor suppressor gene at chromosome 3p14.2. Deletions in FHIT gene were reported in different types of cancer including breast cancer. In this study, we investigated the loss of heterozygosity (LOH) incidence that target FHIT genomic structure and chromosome 3p in cancerous and pre-neoplastic lesions of Egyptian breast patients. Genomic DNA was isolated from tumor tissues and their normal counterparts of 55 Egyptian patients diagnosed with breast cancer and 11 patients diagnosed with preneoplastic breast lesions. LOH was detected in 51% of breast cancer cases in at least one microsatellite marker of the four investigated markers. While, none of the markers showed LOH among the pre-neoplastic breast lesions. We also observed a significant association between LOH and invasive ductal carcinoma (IDC) histopathological type while no association observed between LOH and patients' age, tumor grade, or lymph node involvement. We also investigated FHIT gene expression profiles in breast cancer using Oncomine database. We found that FHIT is significantly reduced in all investigated studies. We conclude that, FHIT is underexpressed in breast cancer tissues compared to their normal counterparts due to the extensive allelic loss that is observed in its gene structure.

A survey of methylated candidate tumor suppressor genes in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a rare malignancy with unique genetic, viral and environmental characteristic that distinguishes it from other head and neck carcinomas. The clinical management of NPC remains challenging largely due to the lack of early detection strategies for this tumor. In our study, we have sought to identify novel genes involved in the pathogenesis of NPC that might provide insight into this tumor's biology and could potentially be used as biomarkers. To identify these genes, we studied the epigenetics of NPC by characterizing a panel of methylation markers. Eighteen genes were evaluated by quantitative methylation-specific polymerase chain reaction (PCR) in cell lines as well as in tissue samples including 50 NPC tumors and 28 benign nasopharyngeal biopsies. Significance was evaluated using Fisher's exact test and quantitative values were optimized using cut off values derived from receiver-operator characteristic curves. The methylation status of AIM1, APC, CALCA, deleted in colorectal carcinomas (DCC), DLEC, deleted in liver cancer 1 (DLC1), estrogen receptor alpha (ESR), FHIT, KIF1A and PGP9.5 was significantly associated with NPC compared to controls. The sensitivity of the individual genes ranged from 26 to 66% and the specificity was above 92% for all genes except FHIT. The combination of PGP9.5, KIF1A and DLEC had a sensitivity of 84% and a specificity of 92%. Ectopic expression of DCC and DLC1 lead to decrease in colony formation and invasion properties. Our results indicate that methylation of novel biomarkers in NPC could be used to enhance early detection approaches. Additionally, our functional studies reveal previously unknown tumor suppressor roles in NPC.

Pathology and biology associated with the fragile FHIT gene and gene product

More than 12 years and >800 scientific publications after the discovery of the first gene at a chromosome fragile site, the FHIT gene at FRA3B, there are still questions to pursue concerning the selective advantage conferred to cells by loss of expression of FHIT, the most frequent target of allele deletion in precancerous lesions and cancers. These questions are considered in light of recent investigations of genetic and epigenetic alterations to the locus and in a retrospective consideration of biological roles of the Fhit protein discovered through functional studies.

Fhit loss in lung preneoplasia: relation to DNA damage response checkpoint activation

Loss of heterozygosity at the FHIT locus is coincident with activation of DNA damage response checkpoint proteins; thus damage at fragile loci may trigger checkpoint activation. We examined preneoplastic lesions adjacent to non-small cell lung carcinomas for alterations to expression of Fhit and activated checkpoint proteins. Expression scores were analyzed for pair-wise associations and correlations among proteins and type of lesion. Hyperplastic and dysplastic lesions were positive for nuclear gammaH2AX expression; 12/20 dysplastic lesions were negative for Fhit expression. Fhit positive lesions showed expression of most checkpoint proteins examined, while Fhit negative lesions showed absence of expression of Chk1 and phosphoChk1. The results show that loss of expression of Fhit is significantly directly correlated with absence of activated Chk1 in dysplasia, and suggest a connection between loss of Fhit and modulation of checkpoint activity.