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

Molecular mechanisms underlying the regulation of tumour suppressor genes in lung cancer

Tumour suppressor genes play a cardinal role in the development of a large array of human cancers, including lung cancer, which is one of the most frequently diagnosed cancers worldwide. Therefore, extensive studies have been committed to deciphering the underlying mechanisms of alterations of tumour suppressor genes in governing tumourigenesis, as well as resistance to cancer therapies. In spite of the encouraging clinical outcomes demonstrated by lung cancer patients on initial treatment, the subsequent unresponsiveness to first-line treatments manifested by virtually all the patients is inherently a contentious issue. In light of the aforementioned concerns, this review compiles the current knowledge on the molecular mechanisms of some of the tumour suppressor genes implicated in lung cancer that are either frequently mutated and/or are located on the chromosomal arms having high LOH rates (1p, 3p, 9p, 10q, 13q, and 17p). Our study identifies specific genomic loci prone to LOH, revealing a recurrent pattern in lung cancer cases. These loci, including 3p14.2 (FHIT), 9p21.3 (p16INK4a), 10q23 (PTEN), 17p13 (TP53), exhibit a higher susceptibility to LOH due to environmental factors such as exposure to DNA-damaging agents (carcinogens in cigarette smoke) and genetic factors such as chromosomal instability, genetic mutations, DNA replication errors, and genetic predisposition. Furthermore, this review summarizes the current treatment landscape and advancements for lung cancers, including the challenges and endeavours to overcome it. This review envisages inspired researchers to embark on a journey of discovery to add to the list of what was known in hopes of prompting the development of effective therapeutic strategies for lung cancer.

Exploring Therapeutic Avenues in Lung Cancer: The Epigenetic Perspective

Lung cancer, primarily non-small cell lung carcinoma (NSCLC) and small cell lung carcinoma (SCLC), is distinguished by its high prevalence and marked mortality rates. Traditional therapeutic approaches, encompassing chemotherapy, radiation, and targeted therapies, frequently show limited efficacy due to acquired resistance and notable side effects. The objective of this review is to introduce a fresh perspective on the therapeutic strategies for lung cancer, emphasizing interventions targeting the epigenetic alterations often seen in this malignancy. This review presents the most recent advancements in the field, focusing on both past and current clinical trials related to the modulation of methylation patterns using diverse molecular agents. Furthermore, an in-depth analysis of the challenges and advantages of these methylation-modifying drugs will be provided, assessing their efficacy as individual treatments and their potential for synergy when integrated with prevailing therapeutic regimens.

Anemoside B4 prevents chronic obstructive pulmonary disease through alleviating cigarette smoke-induced inflammatory response and airway epithelial hyperplasia

BACKGROUND

Cigarette smoke (CS) is one of the major risk factors for chronic obstructive pulmonary disease (COPD) and increases the risk of lung cancer (LC). Anemoside B4 (B4) is the main bioactive ingredient in Pulsatilla chinensis (P. chinensis), a traditional medicinal herb for various diseases. It has a wide range of anti-inflammatory, anti-oxidation and anti-cancer activities. However, in recent years, there is no relevant literature report on the therapeutic effect of B4 on COPD, and the anti-inflammatory and inhibitory effects of anemoside B4 on basal cell hyperplasia in CS-induced COPD have not been clearly established.

PURPOSE

In the present study, we investigated whether anemoside B4 could alleviate CS or cigarette smoke extract (CSE) induced inflammation of COPD and further prevent basal cell hyperplasia, hoping to find its possible mechanism.

METHODS

In this study, a COPD mouse model was established in C57BL mice by CS exposure 3 months. Bronchial pathology and basal cell hyperplasia were observed by HE staining and immunostaining. The contents of glutathione peroxidase catalase (GSH-PX), malondialdehyde (MDA) and superoxide dismutase (MPO) were determined by GSH-PX, MDA and SOD assay kits, respectively. 16HBE cells were cultured with 5% CSE with or without treatment with B4 (1, 10, 100 μM) or DEX (20 μM) in vitro. Cell viability was assessed by a cell counting kit 8 (CCK-8). Reactive oxygen species (ROS) generation was tested by DCFH-DA. Moreover, anti-inflammatory mechanism of anemoside B4 was further determined by pro-inflammatory cytokines production using RT-PCR. Protein expression levels of MAPK/AP-1/TGF-β signaling pathway were measured by western blot.

RESULTS

Anemoside B4 improved the lung function of mice, relieved lung inflammation and reduced the MDA, MPO and GSH-Px in the plasma. At the same time, B4 repressed the oxidative stress response and played a role in balancing the levels of protease and anti-protease. During the process of bronchial basal cell hyperplasia, B4 alleviated the degree of cell hyperplasia, and prevented further deterioration of hyperplasia through increased P53 and inhibited FHIT protein. In addition, B4 reduced ROS levels in human bronchial epithelial cells stimulated by CSE in vitro study. Meanwhile, B4 treatment also significantly attenuated increased IL-1β, TGF-β, IL-8 and TNF-α from CSE treated human bronchial epithelial cells. The expression of p-P38, AP-1(c-fos, and c-Jun), TGF-β proteins in MAPK/AP-1/TGF-β signaling pathway were decreased and the signal cascade reaction was blocked.

CONCLUSION

Anemoside B4 protects against CS-induced COPD. These findings indicated that B4 may have therapeutic potential for the prevention and treatment of COPD.

Tumor Suppressor 4.1N/EPB41L1 is Epigenetic Silenced by Promoter Methylation and MiR-454-3p in NSCLC

Non–small-cell lung cancer (NSCLC) is divided into three major histological types, namely, lung adenocarcinoma (LUAD), lung squamous cell carcinoma (LUSC), and large-cell lung carcinoma (LCLC). We previously identified that 4.1N/EPB41L1 acts as a tumor suppressor and is reduced in NSCLC patients. In the current study, we explored the underlying epigenetic mechanisms of 4.1N/EPB41L1 reduction in NSCLC. The 4.1N/EPB41L1 gene promoter region was highly methylated in LUAD and LUSC patients. LUAD patients with higher methylation level in the 4.1N/EPB41L1 gene promoter (TSS1500, cg13399773 or TSS200, cg20993403) had a shorter overall survival time (Log-rank p = 0.02 HR = 1.509 or Log-rank p = 0.016 HR = 1.509), whereas LUSC patients with higher methylation level in the 4.1N/EPB41L1 gene promoter (TSS1500 cg13399773, TSS1500 cg07030373 or TSS200 cg20993403) had a longer overall survival time (Log-rank p = 0.045 HR = 0.5709, Log-rank p = 0.018 HR = 0.68 or Log-rank p = 0.014 HR = 0.639, respectively). High methylation of the 4.1N/EPB41L1 gene promoter appeared to be a relatively early event in LUAD and LUSC. DNA methyltransferase inhibitor 5-Aza-2′-deoxycytidine restored the 4.1N/EPB41L1 expression at both the mRNA and protein levels. MiR-454-3p was abnormally highly expressed in NSCLC and directly targeted 4.1N/EPB41L1 mRNA. MiR-454-3p expression was significantly correlated with 4.1N/EPB41L1 expression in NSCLC patients (r = −0.63, p < 0.0001). Therefore, we concluded that promoter hypermethylation of the 4.1N/EPB41L1 gene and abnormally high expressed miR-454-3p work at different regulation levels but in concert to restrict 4.1N/EPB41L1 expression in NSCLC. Taken together, this work contributes to elucidate the underlying epigenetic disruptions of 4.1N/EPB41L1 deficiency in NSCLC.

A transdisciplinary approach to understand the epigenetic basis of race/ethnicity health disparities

Health disparities correspond to differences in disease burden and mortality among socially defined population groups. Such disparities may emerge according to race/ethnicity, socioeconomic status and a variety of other social contexts, and are documented for a wide range of diseases. Here, we provide a transdisciplinary perspective on the contribution of epigenetics to the understanding of health disparities, with a special emphasis on disparities across socially defined racial/ethnic groups. Scientists in the fields of biological anthropology, bioinformatics and molecular epidemiology provide a summary of theoretical, statistical and practical considerations for conducting epigenetic health disparities research, and provide examples of successful applications from cancer research using this approach.

DNA Methylation Change Profiling of Colorectal Disease: Screening towards Clinical Use

Colon cancer remains one of the leading causes of cancer-related deaths worldwide. Transformation of colon epithelial cells into invasive adenocarcinomas has been well known to be due to the accumulation of multiple genetic and epigenetic changes. In the past decade, the etiology of inflammatory bowel disease (IBD) which is characterized by chronic inflammation of the intestinal mucosa, was only partially explained by genetic studies providing susceptibility loci, but recently epigenetic studies have provided critical evidences affecting IBD pathogenesis. Over the past decade, A deep understanding of epigenetics along with technological advances have led to identifying numerous genes that are regulated by promoter DNA hypermethylation in colorectal diseases. Recent advances in our understanding of the role of DNA methylation in colorectal diseases could improve a multitude of powerful DNA methylation-based biomarkers, particularly for use as diagnosis, prognosis, and prediction for therapeutic approaches. This review focuses on the emerging potential for translational research of epigenetic alterations into clinical utility as molecular biomarkers. Moreover, this review discusses recent progress regarding the identification of unknown hypermethylated genes in colon cancers and IBD, as well as their possible role in clinical practice, which will have important clinical significance, particularly in the era of the 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.

Genome-Wide Analysis of the DNA Methylation Profile Identifies the Fragile Histidine Triad (FHIT) Gene as a New Promising Biomarker of Crohn's Disease

Inflammatory bowel disease is known to be associated with a genetic predisposition involving multiple genes; however, there is growing evidence that abnormal interactions with environmental factors, particularly epigenetic factors, can also significantly contribute to the development of inflammatory bowel disease (IBD). Although many genome-wide association studies have been performed to identify the genetic changes underlying the pathogenesis of Crohn’s disease, the role of epigenetic alterations based on molecular complications arising from Crohn’s disease (CD) is poorly understood. We employed an unbiased approach to define DNA methylation alterations in colonoscopy samples from patients with CD using the HumanMethylation450K BeadChip platform. Technical and functional validation was performed by methylation-specific PCR (MSP) and bisulfite sequencing of a validation set of 207 patients with CD samples. Immunohistochemistry (IHC) analysis was performed in the representative sample sets. DNA methylation profile in CD revealed that 135 probes (24 hypermethylated and 111 hypomethylated probes) were differentially methylated. We validated the methylation levels of 19 genes that showed hypermethylation in patients with CD compared with normal controls. We uniquely identified that the fragile histidine triad (FHIT) gene was hypermethylated in a disease-specific manner and its protein level was downregulated in patients with CD. Pathway analysis of the hypermethylated candidates further suggested putative molecular interactions relevant to IBD pathology. Our data provide information on the biological and clinical implications of DNA hypermethylated genes in CD, identifying FHIT methylation as a promising new biomarker for CD. Further study of the role of FHIT in IBD pathogenesis may lead to the development of new therapeutic targets.

Folate deficiency and aberrant DNA methylation and expression of FHIT gene were associated with cervical pathogenesis

Aberrant DNA methylation is a recognized feature in various types of human cancer, and folate has a vital role in the epigenetics of mammalian cells by supplying methyl groups for DNA methylation reactions. Fragile histidine triad (FHIT) is a tumor suppressor gene that is frequently silenced in cervical cancer (CC) and preneoplastic lesions. Promoter hypermethylation was previously observed in CC, and its epigenetic silencing has been observed at mRNA or protein levels. Changes in folate intake to modulate DNA methylation may be a mechanistic link to cancer, but this remains to be elucidated. The aim of the present study was to evaluate the influences of folate on FHIT gene methylation and expression in the progression of cervical cancerization. In the present study, red blood cell (RBC) folate levels, FHIT gene methylation status, and mRNA and protein expression levels were detected in 254 women, including normal cervix (NC, n=80), cervical intraepithelial neoplasm grade 1 (CIN1, n=55; CIN2/3, n=55) and cervical squamous cell carcinoma (SCC, n=64) samples. The methylation status of FHIT gene and its mRNA and protein expression levels were measured in CaSki (HPV16 positive) and C33A (HPV16 negative) CC cells treated with different concentrations of folate. The results indicated that FHIT gene methylation rate increased with the severity of cervix lesions, however, RBC folate levels, FHIT mRNA and protein expression levels were reduced. The proliferation inhibition rate, apoptosis rate, and FHIT protein and mRNA expression levels increased along with rising concentrations of folate, whereas the degree of FHIT gene methylation gradually weakened in CaSki or C33A cell lines. The present findings indicated that folate deficiency, FHIT gene promoter hypermethylation and reduced expression were significantly associated with cervical carcinogenesis. The results indicated that folate was able to enhance apoptosis and inhibit the cervical cell proliferation while regulating FHIT gene methylation and expression. Adequate intake of folate to maintain normal DNA methylation status is an effective way for cervical lesions prevention, and demethylation treatment may offer a new strategy for therapy of CC.

Methyltransferase G9a promotes cervical cancer angiogenesis and decreases patient survival

Research suggests that the epigenetic regulator G9a, a H3K9 histone methyltransferase, is involved in cancer invasion and metastasis. Here we show that G9a is linked to cancer angiogenesis and poor patient survival. Invasive cervical cancer has a higher G9a expression than cancer precursors or normal epithelium. Pharmacological inhibition and genetic silencing of G9a suppresses H3K9 methylation, cancer cell proliferation, angiogenesis, and cancer cell invasion/migration, but not apoptosis. Microarray and quantitative reverse transcription polymerase chain reaction analyses reveal that G9a induces a cohort of angiogenic factors that include angiogenin, interleukin-8, and C-X-C motif chemokine ligand 16. Depressing G9a by either pharmacological inhibitor or gene knock down significantly reduces angiogenic factor expression. Moreover, promoting G9a gene expression augments transcription and angiogenic function. A luciferase reporter assay suggests that knockdown of G9a inhibits transcriptional activation of interleukin-8. G9a depletion suppresses xenograft tumor growth in mouse model, which is linked to a decrease in microvessel density and proliferating cell nuclear antigen expression. Clinically, higher G9a expression correlates with poorer survival for cancer patients. For patients’ primary tumors a positive correlation between G9a expression and microvessel density also exists. In addition to increasing tumor cell proliferation, G9a promotes tumor angiogenesis and reduces the patient survival rate. G9a may possess great value for targeted therapies.

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.