Lung cancer epigenetics: From knowledge to applications

Research trend of lung cancer epigenetics research: Bibliometric and visual analysis of top-100 cited documents

Background

Lung cancer is a highly prevalent cancer on a global scale and its oncogenic process is driven by the accumulation of multiple pathological events. Epigenetics has gained significant recognition in recent years as a crucial contributor to the development of lung cancer. Epigenetics include processes such as DNA methylation, histone modification, chromatin remodeling, and RNA modification. These pathways lead to enduring alterations in genetic phenotypes, which are crucial in the advancement and growth of lung cancer. However, the specific mechanisms and roles of epigenetics in lung cancer still need to be further elucidated.

Methods

We obtained publications from the Web of Science databases and applied a rigorous search method to filter them. Ultimately, we gathered high-quality publications that had received the highest 100 number of citations. The data were processed and visualized by various bibliometric tools.

Results

The 100 papers had varying numbers of citations, with the lowest being 491 and the most being 6316. On average, each work received 1119 citations. A total of 1056 co-authors were involved in publishing these papers in 59 journals from 185 institutions in 27 countries. The majority of high-caliber research in the subject of lung cancer epigenetics is conducted in advanced countries, with the United States taking the lead in terms of both the quantity of articles produced and their academic influence. The study of DNA methylation has been a longstanding research priority in the discipline. With the development of next-generation sequencing technology in recent years, research related to non-coding RNA has become a research hotspot. Future research directions may focus more on exploring the mechanisms of action of messenger RNA and circular RNA and developing targeted treatment strategies based on non-coding RNA drugs.

Conclusion

We analyzed 100 top lung cancer and epigenetics documents through various bibliometric analysis tools. This study provides a concise overview of the findings from prior research, anticipates future research directions, and offers potential avenues for additional investigation.

N6-methyladenosine-modified SRPK1 promotes aerobic glycolysis of lung adenocarcinoma via PKM splicing

BACKGROUND

The RNA N6-methyladenosine (m6A) modification has become an essential hotspot in epigenetic modulation. Serine-arginine protein kinase 1 (SRPK1) is associated with the pathogenesis of various cancers. However, the m6A modification of SRPK1 and its association with the mechanism of in lung adenocarcinoma (LUAD) remains unclear.

METHODS

Western blotting and polymerase chain reaction (PCR) analyses were carried out to identify gene and protein expression. m6A epitranscriptomic microarray was utilized to the assess m6A profile. Loss and gain-of-function assays were carried out elucidate the impact of METTL3 and SRPK1 on LUAD glycolysis and tumorigenesis. RNA immunoprecipitation (RIP), m6A RNA immunoprecipitation (MeRIP), and RNA stability tests were employed to elucidate the SRPK1's METTL3-mediated m6A modification mechanism in LUAD. Metabolic quantification and co-immunoprecipitation assays were applied to investigate the molecular mechanism by which SRPK1 mediates LUAD metabolism.

RESULTS

The epitranscriptomic microarray assay revealed that SRPK1 could be hypermethylated and upregulated in LUAD. The main transmethylase METTL3 was upregulated and induced the aberrant high m6A levels of SRPK1. Mechanistically, SRPK1's m6A sites were directly methylated by METTL3, which also stabilized SRPK1 in an IGF2BP2-dependent manner. Methylated SRPK1 subsequently promoted LUAD progression through enhancing glycolysis. Further metabolic quantification, co-immunoprecipitation and western blot assays revealed that SRPK1 interacts with hnRNPA1, an important modulator of PKM splicing, and thus facilitates glycolysis by upregulating PKM2 in LUAD. Nevertheless, METTL3 inhibitor STM2457 can reverse the above effects in vitro and in vivo by suppressing SRPK1 and glycolysis in LUAD.

CONCLUSION

It was revealed that in LUAD, aberrantly expressed METTL3 upregulated SRPK1 levels via an m6A-IGF2BP2-dependent mechanism. METTL3-induced SRPK1 fostered LUAD cell proliferation by enhancing glycolysis, and the small-molecule inhibitor STM2457 of METTL3 could be an alternative novel therapeutic strategy for individuals with LUAD.

m6A modification of CDC5L promotes lung adenocarcinoma progression through transcriptionally regulating WNT7B expression

Cell division cycle 5-like (CDC5L) protein is implicated in the development of various cancers. However, its role in the progression of lung adenocarcinoma (LUAD) remains uncertain. Our findings revealed frequent upregulation of CDC5L in LUAD, which correlated with poorer overall survival rates and advanced clinical stages. In vitro experiments demonstrated that CDC5L overexpression stimulated the proliferation, migration, and invasion of LUAD cells, whereas CDC5L knockdown exerted suppressive effects on these cellular processes. Furthermore, silencing CDC5L significantly inhibited tumor growth and metastasis in a xenograft mouse model. Mechanistically, CDC5L activates the Wnt/β-catenin signaling pathway by transcriptionally regulating WNT7B, thereby promoting LUAD progression. Besides, METTL14-mediated m6A modification contributed to CDC5L upregulation in an IGF2BP2-dependent manner. Collectively, our study uncovers a novel molecular mechanism by which the m6A-induced CDC5L functions as an oncogene in LUAD by activating the Wnt/β-catenin pathway through transcriptional regulation of WNT7B, suggesting that CDC5L may serve as a promising prognostic marker and therapeutic target for LUAD.

CircSLC25A16 facilitates the development of non-small-cell lung cancer through the miR-335-5p/CISD2 axis

BACKGROUND

Non-small-cell lung cancer (NSCLC) is a common malignancy with high morbidity and mortality. Circular RNAs are widely involved in NSCLC progression. However, the mechanism of circSLC25A16 in NSCLC has not been reported.

METHODS

The expressions of circSLC25A16, microRNA-335-5p (miR-335-5p), and CDGSH iron-sulfur domain-containing protein 2 (CISD2) were monitored by quantitative real-time fluorescence polymerase chain reaction. Western blot was also carried out to measure the protein levels of CISD2, hexokinase 2 (HK2), and lactate dehydrogenase A (LDHA). For functional analysis, cell counting kit-8 assay, 5-ethynyl-2'-deoxyuridine, flow cytometry, transwell, and wound healing assays were utilized to examine cell proliferation, apoptosis, and migration. Glucose uptake and lactate production were detected using commercial kits. The relationship between miR-335-5p and circSLC25A16 or CISD2 was verified by dual-luciferase reporter and RNA immunoprecipitation assays. Furthermore, tumor xenograft was established to explore the function of circSLC25A16 in vivo.

RESULTS

CircSLC25A16 and CISD2 were overexpressed in NSCLC, but miR-335-5p was downregulated. CircSLC25A16 acted as a miR-335-5p sponge, and silencing of circSLC25A16 arrested cell proliferation, migration, and glycolysis, and promoted apoptosis, but these impacts were resumed by miR-335-5p inhibition. CISD2 was a miR-335-5p target, and overexpression of CISD2 abolished the suppressive function of miR-335-5p mimic on the malignant behavior of NSCLC cells. CircSLC25A16 could adsorb miR-335-5p to mediate CISD2 expression. Additionally, silencing circSLC25A16 restrained the growth of NSCLC tumor xenograft in vivo.

CONCLUSION

CircSLC25A16 facilitated NSCLC progression via the miR-335-5p/CISD2 axis, implying that circSLC25A16 may serve as a novel biomarker for NSCLC treatment.

Identification of a DNA-methylome-based signature for prognosis prediction in driver gene-negative lung adenocarcinoma

"Driver gene-negative" lung adenocarcinoma (LUAD) was of rare treatment options and a poor prognosis. Presently, for them, few biomarkers are available for stratification analysis to make appropriate treatment strategy. This study aimed to develop a DNA-methylome-based signature to realize the precise risk-stratifying. Here, an Illumina MethylationEPIC Beadchip was applied to obtain differentially methylated CpG sites (DMCs). A four-CpG-based signature, named as TLA, was successfully established, whose prognosis-predicting power was well verified in one internal (n = 78) and other external (n = 110) validation cohorts. Patients with high-risk scores had shorter overall survival (OS) in all cohorts [hazard ratio (HR): 11.79, 5.16 and 2.99, respectively]. Additionally, it can effectively divide patients into low-risk and high-risk groups, with significantly different OS in the diverse subgroups stratified by the standard clinical parameters. As an independent prognostic factor, TLA may assist in improving the nomogram's 5-year OS-predicting ability (AUC 0.756, 95% CI:0.695-0.816), superior to TNM alone (AUC 0.644, 95% CI: 0.590-0.698). Additionally, the relationship of TLA-related genes, TAC1, LHX9, and ALX1, with prognosis and tumour invasion made them serve as potential therapy targets for driver gene-negative LUAD.

Effects of valproic acid on wound healing of the abdominal wall musculoaponeurotic layer: an experimental study in rats

INTRODUCTION

valproic acid (VPA), an epigenetic drug, has potential for the treatment of neoplasms. Its effects on the healing of the peritoneal-musculo-aponeurotic plane (PMA) of the abdominal wall are studied.

METHOD

sixty Wistar rats were allocated into two groups: experimental (VPA) and control (0.9% sodium chloride), treated daily, starting three days before the intervention and until euthanasia. Under anesthesia, a median laparotomy was performed and repaired with two synthetic layers. Assessments took place 3, 7 and 14 days after surgery. The integrity of the wounds, the quality of the inflammatory reaction, the intensity of the leukocyte infiltrate, collagen synthesis, the intensity of angiogenesis and the presence of myofibroblasts were studied.

RESULTS

there was dehiscence of the PMA plane in 11 of the 30 animals (p=0.001) in the experimental group. There was no difference in the quality and intensity of the inflammatory reaction. Immunohistochemistry revealed, in the experimental group, less collagen I (p3=0.003, p7=0.013 and p14=0.001) and more collagen III (p3=0.003, p7=0.013 and p14= 0.001). Collagen evaluated by Sirus Supra Red F3BA showed, in the experimental group, less collagen at all three times (p<0.001) with less collagen I and collagen III (p<0.001). A lower number of vessels was found on the 3rd day (p<0.001) and on the 7th day (p=0.001) and did not affect the number of myofibroblasts.

CONCLUSION

VPA showed dehiscence of the PMA plane, with less deposition of total collagen and collagen I, less angiogenic activity, without interfering with the number of myofibroblasts.

Systematic analysis of IGF2BP family members in non-small-cell lung cancer

BACKGROUND

The insulin-like growth factor-2 mRNA-binding proteins 1, 2, and 3 (IGF2BP1, IGF2BP2, and IGF2BP3) are known to be involved in tumorigenesis, metastasis, prognosis, and cancer immunity in various human cancers, including non-small cell lung cancer (NSCLC). However, the literature on NSCLC largely omits the specific context of lung squamous cell carcinoma (LUSC), an oversight we aim to address.

METHODS

Our study evaluated the differential expression of IGF2BP family members in tumors and normal tissues. Meta-analyses were conducted to assess the prognostic value of IGF2BPs in lung adenocarcinoma (LUAD) and LUSC. Additionally, correlations between IGF2BPs and tumor immune cell infiltration, mutation characteristics, chemotherapy sensitivity, and tumor mutation burden (TMB) were investigated. GSEA was utilized to delineate biological processes and pathways associated with IGF2BPs.

RESULTS

IGF2BP2 and IGF2BP3 expression were found to be upregulated in LUSC patients. IGF2BP2 mRNA levels were correlated with cancer immunity in both LUSC and LUAD patients. A higher frequency of gene mutations was observed in different IGF2BP1/2/3 expression groups in LUAD compared to LUSC. Meta-analyses revealed a significant negative correlation between overall survival (OS) and IGF2BP2/3 expression in LUAD patients but not in LUSC patients. GSEA indicated a positive association between VEGF and IGF2BP family genes in LUAD, while matrix metallopeptidase activity was inversely correlated with IGF2BP family genes in LUSC. Several chemotherapy drugs showed significantly lower IC50 values in high IGF2BP expression groups in both LUAD and LUSC.

CONCLUSION

Our findings indicated that IGF2BPs play different roles in LUAD and LUSC. This divergence highlights the need for tailored therapeutic strategies and prognostic tools, cognizant of the unique molecular profiles of LUAD and LUSC.

Unlocking the future of cancer diagnosis - promises and challenges of ctDNA-based liquid biopsies in non-small cell lung cancer

The advent of liquid biopsies has brought significant changes to the diagnosis and monitoring of non-small cell lung cancer (NSCLC), presenting both promise and challenges. Molecularly targeted drugs, capable of enhancing survival rates, are now available to around a quarter of NSCLC patients. However, to ensure their effectiveness, precision diagnosis is essential. Circulating tumor DNA (ctDNA) analysis as the most advanced liquid biopsy modality to date offers a non-invasive method for tracking genomic changes in NSCLC. The potential of ctDNA is particularly rooted in its ability to furnish comprehensive (epi-)genetic insights into the tumor, thereby aiding personalized treatment strategies. One of the key advantages of ctDNA-based liquid biopsies in NSCLC is their ability to capture tumor heterogeneity. This capability ensures a more precise depiction of the tumor's (epi-)genomic landscape compared to conventional tissue biopsies. Consequently, it facilitates the identification of (epi-)genetic alterations, enabling informed treatment decisions, disease progression monitoring, and early detection of resistance-causing mutations for timely therapeutic interventions. Here we review the current state-of-the-art in ctDNA-based liquid biopsy technologies for NSCLC, exploring their potential to revolutionize clinical practice. Key advancements in ctDNA detection methods, including PCR-based assays, next-generation sequencing (NGS), and digital PCR (dPCR), are discussed, along with their respective strengths and limitations. Additionally, the clinical utility of ctDNA analysis in guiding treatment decisions, monitoring treatment response, detecting minimal residual disease, and identifying emerging resistance mechanisms is examined. Liquid biopsy analysis bears the potential of transforming NSCLC management by enabling non-invasive monitoring of Minimal Residual Disease and providing early indicators for response to targeted treatments including immunotherapy. Furthermore, considerations regarding sample collection, processing, and data interpretation are highlighted as crucial factors influencing the reliability and reproducibility of ctDNA-based assays. Addressing these challenges will be essential for the widespread adoption of ctDNA-based liquid biopsies in routine clinical practice, ultimately paving the way toward personalized medicine and improved outcomes for patients with NSCLC.

Exploring tumor organoids for cancer treatment

As a life-threatening chronic disease, cancer is characterized by tumor heterogeneity. This heterogeneity is associated with factors that lead to treatment failure and poor prognosis, including drug resistance, relapse, and metastasis. Therefore, precision medicine urgently needs personalized tumor models that accurately reflect the tumor heterogeneity. Currently, tumor organoid technologies are used to generate in vitro 3D tissues, which have been shown to precisely recapitulate structure, tumor microenvironment, expression profiles, functions, molecular signatures, and genomic alterations in primary tumors. Tumor organoid models are important for identifying potential therapeutic targets, characterizing the effects of anticancer drugs, and exploring novel diagnostic and therapeutic options. In this review, we describe how tumor organoids can be cultured and summarize how researchers can use them as an excellent tool for exploring cancer therapies. In addition, we discuss tumor organoids that have been applied in cancer therapy research and highlight the potential of tumor organoids to guide preclinical research.

Reference intervals of Cyfra21-1 and CEA in healthy adult Han Chinese population

Objective

This study aimed to establish the reference intervals of Cyfra21-1 and CEA for the local screening populations using a chemiluminescence method.

Methods

A total of 4845 healthy adults and 190 lung cancer patients were included from the First Hospital of Hebei Medical University. The levels of Cyfra21-1 and CEA were measured to establish the local reference intervals.

Results

The upper limit reference intervals for Cyfra21-1 and CEA were determined as 3.19 ng/ml and 3.13 ng/ml, respectively. Notably, both Cyfra21-1 and CEA levels were found to be higher in males than in females. Additionally, both biomarkers showed an increasing trend with age.In terms of diagnostic efficacy, the receiver operating characteristic (ROC) curve areas for Cyfra21-1, CEA, and their combination in lung cancer were 0.86, 0.73, and 0.91, respectively.

Conclusion

Our study revealed that the reference intervals of Cyfra21-1 and CEA in the local population differed from the established reference intervals. Furthermore, both biomarkers exhibited gender-dependent variations and demonstrated a positive correlation with age. Combining the two biomarkers showed potential for improving the diagnosis rate of lung cancer.

Coregulatory effects of multiple histone modifications in key ferroptosis-related genes for lung adenocarcinoma

Aim: The present study was designed to investigate the coregulatory effects of multiple histone modifications (HMs) on gene expression in lung adenocarcinoma (LUAD). Materials & methods: Ten histones for LUAD were analyzed using ChIP-seq and RNA-seq data. An innovative computational method is proposed to quantify the coregulatory effects of multiple HMs on gene expression to identify strong coregulatory genes and regions. This method was applied to explore the coregulatory mechanisms of key ferroptosis-related genes in LUAD. Results: Nine strong coregulatory regions were identified for six ferroptosis-related genes with diverse coregulatory patterns (CA9, PGD, CDKN2A, PML, OTUB1 and NFE2L2). Conclusion: This quantitative method could be used to identify important HM coregulatory genes and regions that may be epigenetic regulatory targets in cancers.

Identification of genetically predicted DNA methylation markers associated with non-small cell lung cancer risk among 34,964 cases and 448,579 controls

BACKGROUND

Although the associations between genetic variations and lung cancer risk have been explored, the epigenetic consequences of DNA methylation in lung cancer development are largely unknown. Here, the genetically predicted DNA methylation markers associated with non-small cell lung cancer (NSCLC) risk by a two-stage case-control design were investigated.

METHODS

The genetic prediction models for methylation levels based on genetic and methylation data of 1595 subjects from the Framingham Heart Study were established. The prediction models were applied to a fixed-effect meta-analysis of screening data sets with 27,120 NSCLC cases and 27,355 controls to identify the methylation markers, which were then replicated in independent data sets with 7844 lung cancer cases and 421,224 controls. Also performed was a multi-omics functional annotation for the identified CpGs by integrating genomics, epigenomics, and transcriptomics and investigation of the potential regulation pathways.

RESULTS

Of the 29,894 CpG sites passing the quality control, 39 CpGs associated with NSCLC risk (Bonferroni-corrected p ≤ 1.67 × 10-6 ) were originally identified. Of these, 16 CpGs remained significant in the validation stage (Bonferroni-corrected p ≤ 1.28 × 10-3 ), including four novel CpGs. Multi-omics functional annotation showed nine of 16 CpGs were potentially functional biomarkers for NSCLC risk. Thirty-five genes within a 1-Mb window of 12 CpGs that might be involved in regulatory pathways of NSCLC risk were identified.

CONCLUSIONS

Sixteen promising DNA methylation markers associated with NSCLC were identified. Changes of the methylation level at these CpGs might influence the development of NSCLC by regulating the expression of genes nearby.

PLAIN LANGUAGE SUMMARY

The epigenetic consequences of DNA methylation in lung cancer development are still largely unknown. This study used summary data of large-scale genome-wide association studies to investigate the associations between genetically predicted levels of methylation biomarkers and non-small cell lung cancer risk at the first time. This study looked at how well larotrectinib worked in adult patients with sarcomas caused by TRK fusion proteins. These findings will provide a unique insight into the epigenetic susceptibility mechanisms of lung cancer.

Integration of bulk RNA sequencing to reveal protein arginine methylation regulators have a good prognostic value in immunotherapy to treat lung adenocarcinoma

Background

Given the differential expression and biological functions of protein arginine methylation (PAM) regulators in lung adenocarcinoma (LUAD), it may be of great value in the diagnosis, prognosis, and treatment of LUAD. However, the expression and function of PAM regulators in LUAD and its relationship with prognosis are unclear.

Methods

8 datasets including 1798 LUAD patients were selected. During the bioinformatic study in LUAD, we performed (i) consensus clustering to identify clusters based on 9 PAM regulators related expression profile data, (ii) to identify hub genes between the 2 clusters, (iii) principal component analysis to construct a PAM.score based on above genes, and (iv) evaluation of the effect of PAM.score on the deconstruction of tumor microenvironment and guidance of immunotherapy.

Results

We identified two different clusters and a robust and clinically practicable prognostic scoring system. Meanwhile, a higher PAM.score subgroup showed poorer prognosis, and was validated by multiple cohorts. Its prognostic effect was validated by ROC (Receiver operating characteristic curve) curve and found to have a relatively good prediction efficacy. High PAM.score group exhibited lower immune score, which associated with an immunosuppressive microenvironment in LUAD. Finally, patients exhibiting a lower PAM.score presented noteworthy therapeutic benefits and clinical advantages.

Conclusion

Our PAM.score model can help clinicians to select personalized therapy for LUAD patients, and PAM.score may act a part in the development of LUAD.

Advances and challenges of first-line immunotherapy for non-small cell lung cancer: A review

The current use of immune checkpoint inhibitors (ICIs) for the treatment of lung cancer has dramatically changed the clinical strategy for metastatic non-small cell lung cancer (mNSCLC). As a result of great achievements in clinical trials, 6 programmed death-1 inhibitors (sintilimab, camrelizumab, tislelizumab, pembrolizumab, cemiplimab, and nivolumab), 2 programmed death-ligand 1 inhibitors (sugemalimab and atezolizumab), and 1 cytotoxic T lymphocyte-associated antigen-4 inhibitor (ipilimumab) have been approved as first-line treatment for mNSCLC by the US Food and Drug Administration. Recently, research on ICIs has shifted from a large number of second-line to first-line settings in clinical trials. Results from first-line trials have shown that almost all driver-negative mNSCLC are treated with ICIs and significantly prolong patient survival; however, the low response rate and adverse reactions to immunotherapy remain to be addressed. Here, we summarize the use of ICIs, including monotherapy and combination therapy, in the first-line treatment of mNSCLC in recent years and discuss the low response rate and adverse reactions of ICIs as well as the challenges and expectations for the first-line treatment of mNSCLC in the future.

Synergistic effect of a nonsteroidal anti-inflammatory drug in combination with topotecan on small cell lung cancer cells

BACKGROUND

The topoisomerase I inhibitor topotecan (TPT) is used in the treatment of recurrent small cell lung cancer (SCLC). However, the drug has a limited success rate and causes distress to patients due to its side effects, such as hematologic toxicities, including anemia and thrombocytopenia. Due to these pharmacokinetic limitations and undesirable side effects of chemotherapeutic drugs, the development of combination therapies has gained popularity in SCLC. Meclofenamic acid (MA), a nonsteroidal anti-inflammatory drug, has demonstrated anticancer effects on various types of cancers through different mechanisms. This study aims to investigate the potential synergistic effects of MA and TPT on the small cell lung cancer cell line DMS114.

METHODS AND RESULTS

To assess the cytotoxic and apoptotic effects of the combined treatment of MA and TPT, trypan blue exclusion assay, Annexin V, acridine orange/propidium iodide staining, western blot, and cell cycle analysis were conducted. The results demonstrated that the combination of MA and TPT elicited synergistic effects by enhancing toxicity in DMS114 cells (P < 0.01) without causing toxicity in healthy epithelial lung cells MRC5. The strongest synergistic effect was observed when the cells were treated with 60 µM MA and 10 nM TPT for 48 h (CI = 0,751; DRI = 10,871).

CONCLUSION

This study, for the first time, furnishes compelling evidence that MA and TPT synergistically reduce cellular proliferation and induce apoptosis in SCLC cells. Combinations of these drugs holds promise as a potential therapeutic strategy to improve efficacy and reduce the side effects associated with TPT.

Epigenetic modifications: Key players in cancer heterogeneity and drug resistance

Cancer heterogeneity and drug resistance remain pivotal obstacles in effective cancer treatment and management. One major contributor to these challenges is epigenetic modifications - gene regulation that does not involve changes to the DNA sequence itself but significantly impacts gene expression. As we elucidate these phenomena, we underscore the pivotal role of epigenetic modifications in regulating gene expression, contributing to cellular diversity, and driving adaptive changes that can instigate therapeutic resistance. This review dissects essential epigenetic modifications - DNA methylation, histone modifications, and chromatin remodeling - illustrating their significant yet complex contributions to cancer biology. While these changes offer potential avenues for therapeutic intervention due to their reversible nature, the interplay of epigenetic and genetic changes in cancer cells presents unique challenges that must be addressed to harness their full potential. By critically analyzing the current research landscape, we identify knowledge gaps and propose future research directions, exploring the potential of epigenetic therapies and discussing the obstacles in translating these concepts into effective treatments. This comprehensive review aims to stimulate further research and aid in developing innovative, patient-centered cancer therapies. Understanding the role of epigenetic modifications in cancer heterogeneity and drug resistance is critical for scientific advancement and paves the way towards improving patient outcomes in the fight against this formidable disease.

M2 tumor-associated macrophage promoted DNA methylation in lung cancer metastasis via intensifying EZH2

This study aimed to explore the interaction between the tumor-associated macrophage (TAM) and enhancer of zeste homolog 2 (EZH2) in tumor microenvironment of lung cancer are obscure. M2 type of TAM was induced by interleukin-4 (IL-4) and interleukin-13 (IL-13) in RAW264.7 cells. Subsequently, the co-culture system of the M2 RAW264.7 treating LLC-1 cells were constructed to evaluate the cell proliferation, migration and invasion abilities. On top of that, the M2 RAW264.7 was injected into the LLC-1 cells-bearing mice. Tumor growth and the number of metastatic nodes were observed. Moreover, DNA methylation, EZH2 expression, target genes of EZH2 and the M2 type TAM-related markers were detected in vivo and in vitro . Further experiments of EZH2 function in lung cancer were carried out by the addition of EZH2 inhibitor (GSK126) and si-EZH2. M2 type of TAM was induced with IL-4 and IL-13 with increased expression of CD206, CD68, CD163 and Arg1. Following co-culture with M2 type TAM, the proliferative, invasive, migrative abilities, tumor growth and metastasis, and the DNA methylation, EZH2 level were strengthened whereas the target genes of EZH2, including p21, CDKN2A, CDKN2B were reduced in LLC-1 cells and LLC-1 cell-bearing mice. Of note, GSK126 and si-EZH2 offset the M2 type TAM's effects, and inhibited the LLC-1 cell metastasis, DNA methylation and tumor growth. M2 type TAM promoted DNA methylation in LLC-1 cells and LLC-1 cell-bearing mice, which is related to the intensified EZH2.

Epigenetic regulation in lung cancer

Lung cancer is indeed a major cause of cancer-related deaths worldwide. The development of tumors involves a complex interplay of genetic, epigenetic, and environmental factors. Epigenetic mechanisms, including DNA methylation (DNAm), histone modifications, and microRNA expression, play a crucial role in this process. Changes in DNAm patterns can lead to the silencing of important genes involved in cellular functions, contributing to the development and progression of lung cancer. MicroRNAs and exosomes have also emerged as reliable biomarkers for lung cancer. They can provide valuable information about early diagnosis and treatment assessment. In particular, abnormal hypermethylation of gene promoters and its effects on tumorigenesis, as well as its roles in the Wnt signaling pathway, have been extensively studied. Epigenetic drugs have shown promise in the treatment of lung cancer. These drugs target the aberrant epigenetic modifications that are involved in the development and progression of the disease. Several factors have been identified as drug targets in non-small cell lung cancer. Recently, combination therapy has been discussed as a successful strategy for overcoming drug resistance. Overall, understanding the role of epigenetic mechanisms and their targeting through drugs is an important area of research in lung cancer treatment.

FUT3 facilitates glucose metabolism of lung adenocarcinoma via activation of NF-κB pathway

OBJECTIVE

Fucosyltransferases (FUTs) molecules have been identified to be involved in carcinogenesis of malignant tumors. Nevertheless, the biological function of fucosyltransferases-3 (FUT3) in lung adenocarcinoma (LUAD) malignant phenotype remains unclear. Herein, we investigated the association between FUT3 and LUAD pathological process.

METHODS

Immunochemistry, RT-qPCR and western blot assays were conducted to evaluate the expression of FUT3 in LUAD and corresponding adjacent tissues. The prognostic value of FUT3 was assessed via Kaplan‑Meier plotter database. The biological process and potential mechanism of FUT3 in LUAD were conducted via GSEA. Additionally, immunofluorescence and metabolite activity detection were performed to determine the potential role of FUT3 in LUAD glucose metabolism. The active biomarkers associated with NF-κB signaling pathway were detected via western blot. Subcutaneous tumor model was conducted to analyze the effect of FUT3 on tumorigenesis of LUAD.

RESULTS

FUT3 was remarkably upregulated in LUAD tissues compared with adjacent tissues from individuals. FUT3 overexpression may predict poor prognosis of LUAD patients. Knockdown of FUT3 significantly inhibited tumor proliferation, migration and glucometabolic alteration in LUAD cells. Moreover, GSEA demonstrated that elevated FUT3 was positively related to NF-κB signaling pathway. Additionally, in vitro and in vivo assays also indicated that downregulation of FUT3 resulted in the suppression of oncogenesis and glucose metabolism via inactivation of NF-κB pathway.

CONCLUSION

Our findings demonstrated that FUT3 was involved in glucometabolic process and tumorigenesis of LUAD via NF-κB signaling pathway. FUT3 may be an optimal target for diagnosis and treatment of LUAD patients.

Identification of specific prognostic markers for lung squamous cell carcinoma based on tumor progression, immune infiltration, and stem index

Introduction

Lung squamous cell carcinoma (LUSC) is a unique subform of nonsmall cell lung cancer (NSCLC). The lack of specific driver genes as therapeutic targets leads to worse prognoses in patients with LUSC, even with chemotherapy, radiotherapy, or immune checkpoint inhibitors. Furthermore, research on the LUSC-specific prognosis genes is lacking. This study aimed to develop a comprehensive LUSC-specific differentially expressed genes (DEGs) signature for prognosis correlated with tumor progression, immune infiltration,and stem index.

Methods

RNA sequencing data for LUSC and lung adenocarcinoma (LUAD) were extracted from The Cancer Genome Atlas (TCGA) data portal, and DEGs analyses were conducted in TCGA-LUSC and TCGA-LUAD cohorts to identify specific DEGs associated with LUSC. Functional analysis and protein-protein interaction network were performed to annotate the roles of LUSC-specific DEGs and select the top 100 LUSC-specific DEGs. Univariate Cox regression and least absolute shrinkage and selection operator regression analyses were performed to select prognosis-related DEGs.

Results

Overall, 1,604 LUSC-specific DEGs were obtained, and a validated seven-gene signature was constructed comprising FGG, C3, FGA, JUN, CST3, CPSF4, and HIST1H2BH. FGG, C3, FGA, JUN, and CST3 were correlated with poor LUSC prognosis, whereas CPSF4 and HIST1H2BH were potential positive prognosis markers in patients with LUSC. Receiver operating characteristic analysis further confirmed that the genetic profile could accurately estimate the overall survival of LUSC patients. Analysis of immune infiltration demonstrated that the high risk (HR) LUSC patients exhibited accelerated tumor infiltration, relative to low risk (LR) LUSC patients. Molecular expressions of immune checkpoint genes differed significantly between the HR and LR cohorts. A ceRNA network containing 19 lncRNAs, 50 miRNAs, and 7 prognostic DEGs was constructed to demonstrate the prognostic value of novel biomarkers of LUSC-specific DEGs based on tumor progression, stemindex, and immune infiltration. In vitro experimental models confirmed that LUSC-specific DEG FGG expression was significantly higher in tumor cells and correlated with immune tumor progression, immune infiltration, and stem index. In vitro experimental models confirmed that LUSC-specific DEG FGG expression was significantly higher in tumor cells and correlated with immune tumor progression, immune infiltration, and stem index.

Conclusion

Our study demonstrated the potential clinical implication of the 7- DEGs signature for prognosis prediction of LUSC patients based on tumor progression, immune infiltration, and stem index. And the FGG could be an independent prognostic biomarker of LUSC promoting cell proliferation, migration, invasion, THP-1 cell infiltration, and stem cell maintenance.

The Usefulness of the Ratio of Antigen-Autoantibody Immune Complexes to Their Free Antigens in the Diagnosis of Non-Small Cell Lung Cancer

Autoantibodies against specific lung cancer-associated antigens have been suggested for the performance of lung cancer diagnosis. This study aimed to evaluate the diagnostic performance of the antigen-autoantibody immune complex (AIC) against its free antigens for CYFRA21-1, ProGRP, neutrophil gelatinase-associated lipocalin (NGAL), and neuron-specific enolase (NSE) in non-small cell lung cancer (NSCLC). In total, 85 patients with NSCLC and 120 healthy controls (HCs) were examined using a 9-guanine DNA chip method. The ratios of AICs to their antigens and the combinations of ratios consisting of two to four markers were calculated. The levels of AICs for CYFRA21-1, ProGRP, NGAL, and NSE were higher than those for their free antigens in all participants. The levels of each free antigens distinguished patients with NSCLC from the HCs. The ratios of the AIC to its antigen and seven combinations of two to four ratios were significantly higher in patients with NSCLC than in the HCs. Excellent diagnostic performance was observed for all combination ratios (C4-1), with 85.9% sensitivity and 86.7% specificity at a 3.51 cut-off. Higher sensitivity was observed in the early stages (0-I) and adenocarcinoma than in stages II-IV and other pathological types. Combining all ratios of AICs and their antigens for all four markers was useful when diagnosing NSCLC.

Drug resistance mechanism and reversal strategy in lung cancer immunotherapy

Among all malignant tumors, lung cancer has the highest mortality and morbidity rates. The non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC) are the most common histological subtypes. Although there are a number of internationally recognized lung cancer therapy regimens, their therapeutic effects remain inadequate. The outlook for individuals with lung carcinoma has ameliorated partly thanks to the intensive study of the tumor microenvironment and immune checkpoint inhibitors. Numerous cancers have been effectively treated with immunotherapy, which has had positive therapeutic results. Global clinical trials have validated that PD-1/PD-L1 inhibitors are effective and safe for treating lung cancer either independently or in combination, and they are gradually being recommended as systemic treatment medications by numerous guidelines. However, the immunotherapy resistance restricts the immunotherapy efficacy due to the formation of tumor immunosuppressive microenvironment and tumor mutations, and immunotherapy is only effective for a small percentage of lung cancer patients. To summarize, while tumor immunotherapy is benefiting an increasing number of lung cancer patients, most of them still develop natural or acquired resistance during immunotherapy. Consequently, a crucial and urgent topic is understanding and tackling drug resistance triggered by immunotherapy in lung cancer treatment. This review will outline the presently recognized mechanisms of immunotherapy resistance and reversal strategies in lung cancer.

CircRNA hsa_circ_0000043 acts as a miR-4492 sponge to promote lung cancer progression via BDNF and STAT3 expression regulation in anti-benzo[a]pyrene-trans-7,8-dihydrodiol-9,10-epoxide-transformed 16HBE cells

Increasing evidence shows that circular RNA (circRNA) plays an important role in the progression of lung cancer. In this study, we found that has_circ_0000043 was highly expressed in 16HBE-T human bronchial epithelial cells that were malignantly transformed by benzo[a]pyrene-trans-7,8-diol-9,10-epoxide via circRNA microarray. We verified that hsa_circ_0000043 was also significantly overexpressed in lung cancer cell lines and tissues. Moreover, hsa_circ_0000043 overexpression was positively correlated with poor clinicopathological parameters, such as tumor-node metastasis stage, distant metastasis, lymph-node metastasis, and overall survival. In vitro assays revealed that hsa_circ_0000043 inhibition suppressed 16HBE-T cell proliferation, migration, and invasion. Furthermore, hsa_circ_0000043 inhibition suppressed tumor growth in a mouse xenograft model. We discovered that hsa_circ_0000043 binds with miR-4492, acting as a miR-4492 sponge. Decreased miR-4492 expression was also associated with poor clinicopathological parameters. Thus, hsa_circ_0000043 was shown to contribute to the proliferation, malignant transformation ability, migration, and invasion of 16HBE-T cells via miR-4492 sponging and BDNF and STAT3 involvement.

SETD2-H3K36ME3: an important bridge between the environment and tumors

Epigenetic regulation plays an important role in the occurrence, development and treatment of tumors. The histone methyltransferase SET-domain-containing 2 (SETD2) plays a key role in mammalian epigenetic regulation by catalyzing histone methylation and interacting with RNA polymerase II to mediate transcription elongation and mismatch repair. As an important bridge between the environment and tumors, SETD2-H3K36me3 plays an important role in the occurrence and development of tumors. Many tumors, including renal cancer, gastric cancer, lung cancer, are closely related to SETD2 gene mutations. As a key component of common tumor suppressor mechanisms, SETD2-H3K36me3is an important target for clinical disease diagnosis and treatment. Here, we reviewed the structure and function of the SETD2 and how SETD2-H3K36me3 functions as a bridge between the environment and tumors to provide an in-depth understanding of its role in the occurrence and development of various tumors, which is of great significance for future disease diagnosis and treatment.

Combination of epidrugs with immune checkpoint inhibitors in cancer immunotherapy: From theory to therapy

Immunotherapy based on immune checkpoint inhibitors (ICIs) has revolutionized treatment strategies in multiple types of cancer. However, the resistance and relapse as associated with the extreme complexity of cancer-immunity interactions remain a major challenge to be resolved. Owing to the epigenome plasticity of cancer and immune cells, a growing body of evidence has been presented indicating that epigenetic treatments have the potential to overcome current limitations of immunotherapy, thus providing a rationalefor the combination of ICIs with epigenetic agents (epidrugs). In this review, we first make an overview about the epigenetic regulations in tumor biology and immunodevelopment. Subsequently, a diverse array of inhibitory agents under investigations targeted epigenetic modulators (Azacitidine, Decitabine, Vorinostat, Romidepsin, Belinostat, Panobinostat, Tazemetostat, Enasidenib and Ivosidenib, etc.) and immune checkpoints (Atezolizmab, Avelumab, Cemiplimab, Durvalumb, Ipilimumab, Nivolumab and Pembrolizmab, etc.) to increase anticancer responses were described and the potential mechanisms were further discussed. Finally, we summarize the findings of clinical trials and provide a perspective for future clinical studies directed at investigating the combination of epidrugs with ICIs as a treatment for cancer.

Novel insights into the multifaceted roles of m6A-modified LncRNAs in cancers: biological functions and therapeutic applications

N6-methyladenosine (m⁶A) is considered as the most common and important internal transcript modification in several diseases like type 2 diabetes, schizophrenia and especially cancer. As a main target of m⁶A methylation, long non-coding RNAs (lncRNAs) have been proved to regulate cellular processes at various levels, including epigenetic modification, transcriptional, post-transcriptional, translational and post-translational regulation. Recently, accumulating evidence suggests that m⁶A-modified lncRNAs greatly participate in the tumorigenesis of cancers. In this review, we systematically summarized the biogenesis of m⁶A-modified lncRNAs and the identified m⁶A-lncRNAs in a variety of cancers, as well as their potential diagnostic and therapeutic applications as biomarkers and therapeutic targets, hoping to shed light on the novel strategies for cancer treatment.

Loss of BLK expression as a potential predictor of poor prognosis and immune checkpoint blockade response in NSCLC and contribute to tumor progression

BACKGROUND

Immune checkpoint blockade (ICB) has been proved to have significant anti-tumor effect in the clinical treatment of non-small cell lung cancer (NSCLC). Therefore, biomarkers predicting ICB response can provide better treatment for patients with NSCLC.

METHODS

Differential expression genes (DEGs) were identified by ImmuCellAI database. Copy number alteration (CNA) was analyzed by cBioPortal. The predicted efficiency of 4 genes on cancer immunotherapy was assessed by ROC analysis. The survival value of BLK was analyzed by Kaplan-Meier plotter and Prognoscan analysis. Clinical significance of BLK IHC-TMA score in NSCLC was also explored. The CCK-8 assay, wound healing assay, western blot assay in vitro and subcutaneous xenograft experiments in vivo were used for investigating the functions of BLK. The RNA-sequencing were performed to screen BLK regulated genes and conducted for GO/KEGG enrichment analysis. The transcriptional regulatory factor of BLK promoter region was predicted by ChIP-seq analysis.

RESULTS

39 common DEGs between ICB Response (R) group and No Response (NR) group with NSCLC were identified, in which the CNA frequency of BLK deletion (> 6%) was found. The predicted efficiency of BLK on immunotherapy was performed best in NSCLC (AUC>0.7). Low expression of BLK was related to NSCLC with significantly poor prognosis. BLK overexpression can inhibit growth of NSCLC via activating apoptosis pathway, inhibiting the G2M checkpoint and Glycolysis pathway. The enrichment analysis indicated that BLK regulated genes related to oncogenic potential in NSCLC. Besides, BLK expression was inhibited via H3K27me3 modification in A549 and H1299 cells. BLK mRNA level was negatively correlated with methylation and positively correlated with the tumor purity in NSCLC.

CONCLUSION

Our study provides strong evidence that low expression of BLK may serve as a biomarker for poor prognosis in NSCLC, while response to ICB therapy and contributes to NSCLC tumor progression.

Cytoplasmic DNAs: Sources, sensing, and roles in the development of lung inflammatory diseases and cancer

Cytoplasmic DNA is emerging as a pivotal contributor to the pathogenesis of inflammatory diseases and cancer, such as COVID-19 and lung carcinoma. However, the complexity of various cytoplasmic DNA-related pathways and their crosstalk remains challenging to distinguish their specific roles in many distinct inflammatory diseases, especially for the underlying mechanisms. Here, we reviewed the latest findings on cytoplasmic DNA and its signaling pathways in inflammatory lung conditions and lung cancer progression. We found that sustained activation of cytoplasmic DNA sensing pathways contributes to the development of common lung diseases, which may result from external factors or mutations of key genes in the organism. We further discussed the interplays between cytoplasmic DNA and anti-inflammatory or anti-tumor effects for potential immunotherapy. In sum, this review aids in understanding the roles of cytoplasmic DNAs and exploring more therapeutic strategies.

Sodium selenite inhibits proliferation of lung cancer cells by inhibiting NF-κB nuclear translocation and down-regulating PDK1 expression which is a key enzyme in energy metabolism expression

As a trace element that maintains homeostasis in human body, selenium has significant anti-tumor activity. However, its exact molecular mechanism remains to be elucidated. Sodium selenite (SSe) is the most widely-distributed inorganic selenium in nature. In this study, we selected SSe as the research object to explore its anti-tumor mechanism in lung cancer. In vitro experiment showed that SSe could inhibit the activation of NF-κB signaling pathway, knowing that NF-κB is an important intracellular nuclear transcription factor that regulates the expression of pyruvate dehydrogenase kinase 1 (PDK1), a key energy metabolism switch affecting the survival status of the whole cell.At the same time, Bay11-7082(NF-κB signaling pathway inhibitors) and SSe resulted in phosphorylation of p65 and IκBα, decreased expression of PDK1 and Bcl-2,and increased expression of Bax in lung cancer cells. Our further study demonstrated that the reduction of PDK1 activity inhibited lactate secretion, reduced mitochondrial membrane potential, caused the release of Cytochrome C (Cyto C), activated mitochondrial respiration, and promoted the apoptosis of lung cancer cells. The in vivo experiment revealed that SSe inhibited the activation of NF-κB signaling pathway, decreased the expression of PDK1, and induced lung cancer cell proliferation and apoptosis. All these findings indicated that SSe promoted lung cancer cell apoptosis by inhibiting the activation of NF-κB signaling pathway, down-regulating PDK1 and activating mitochondrial apoptosis pathway.

Budding uninhibited by benzimidazoles 1 overexpression is associated with poor prognosis and malignant phenotype: A promising therapeutic target for lung adenocarcinoma

BACKGROUND

The budding uninhibited by benzimidazoles (BUB) family is involved in the cell cycle process as mitotic checkpoint components. Abnormal proliferation is a vital process in the development of lung adenocarcinoma (LUAD). Nevertheless, the roles of BUB1 in LUAD remain unclear. In this study, we evaluated the prognostic value and biological functions of BUB1 in LUAD using data from The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), clinical LUAD samples, and in vitro experiments.

METHODS

The expression, prognostic significance, functions, immune infiltration, and methylation of BUB1 in LUAD were comprehensively analyzed using TCGA, GEO, Gene Expression Profiling Interactive Analysis, Metascape, cBioPortal, MethSurv, and cancerSEA databases. Furthermore, we performed a battery of in vitro experiments and immunohistochemistry (IHC) to verify the bioinformatics results.

RESULTS

Multivariate analysis revealed that BUB1 overexpression was an independent prognostic factor (hazard ratio = 1.499, p = 0.013). Functional enrichment analysis showed that BUB1 was correlated with cell cycle, proliferation, DNA repair, DNA damage, and invasion (p < 0.05). Finally, in vitro experiments showed that downregulation of BUB1 inhibited the proliferation, migration, and invasion of LUAD cells and promoted LUAD cell apoptosis. IHC also showed that BUB1 was overexpressed in LUAD (p < 0.001) and was significantly associated with poor prognosis (p < 0.001).

CONCLUSIONS

Our bioinformatics and IHC analyses revealed that BUB1 overexpression was an adverse prognostic factor in LUAD. In vitro experiments demonstrated that BUB1 promoted tumor cell proliferation, migration, and invasion in LUAD. These results indicated that BUB1 was a promising biomarker and potential therapeutic target in LUAD.

The Importance of the Immune System and Molecular Cell Signaling Pathways in the Pathogenesis and Progression of Lung Cancer

Lung cancer is a disease that in recent years has become one of the greatest threats to modern society. Every year there are more and more new cases and the percentage of deaths caused by this type of cancer increases. Despite many studies, scientists are still looking for answers regarding the mechanisms of lung cancer development and progression, with particular emphasis on the role of the immune system. The aim of this literature review was to present the importance of disorders of the immune system and the accompanying changes at the level of cell signaling in the pathogenesis of lung cancer. The collected results showed that in the process of immunopathogenesis of almost all subtypes of lung cancer, changes in the tumor microenvironment, deregulation of immune checkpoints and abnormalities in cell signaling pathways are involved, which contribute to the multistage and multifaceted carcinogenesis of this type of cancer. We, therefore, suggest that in future studies, researchers should focus on a detailed analysis of tumor microenvironmental immune checkpoints, and to validate their validity, perform genetic polymorphism analyses in a wide range of patients and healthy individuals to determine the genetic susceptibility to lung cancer development. In addition, further research related to the analysis of the tumor microenvironment; immune system disorders, with a particular emphasis on immunological checkpoints and genetic differences may contribute to the development of new personalized therapies that improve the prognosis of patients.

Epigenetic regulation of stem cells in lung cancer oncogenesis and therapy resistance

Epigenetics plays an important role in regulating stem cell signaling, as well as in the oncogenesis of lung cancer and therapeutic resistance. Determining how to employ these regulatory mechanisms to treat cancer is an intriguing medical challenge. Lung cancer is caused by signals that cause aberrant differentiation of stem cells or progenitor cells. The different pathological subtypes of lung cancer are determined by the cells of origin. Additionally, emerging studies have demonstrated that the occurrence of cancer treatment resistance is connected to the hijacking of normal stem cell capability by lung cancer stem cells, especially in the processes of drug transport, DNA damage repair, and niche protection. In this review, we summarize the principles of the epigenetic regulation of stem cell signaling in relation to the emergence of lung cancer and resistance to therapy. Furthermore, several investigations have shown that the tumor immune microenvironment in lung cancer affects these regulatory pathways. And ongoing experiments on epigenetics-related therapeutic strategies provide new insight for the treatment of lung cancer in the future.

Longitudinal monitoring of cell-free DNA methylation in ALK-positive non-small cell lung cancer patients

BACKGROUND

DNA methylation (5-mC) signals in cell-free DNA (cfDNA) of cancer patients represent promising biomarkers for minimally invasive tumor detection. The high abundance of cancer-associated 5-mC alterations permits parallel and highly sensitive assessment of multiple 5-mC biomarkers. Here, we performed genome-wide 5-mC profiling in the plasma of metastatic ALK-rearranged non-small cell lung cancer (NSCLC) patients receiving tyrosine kinase inhibitor therapy. We established a strategy to identify ALK-specific 5-mC changes from cfDNA and demonstrated the suitability of the identified markers for cancer detection, prognosis, and therapy monitoring.

METHODS

Longitudinal plasma samples (n = 79) of 21 ALK-positive NSCLC patients and 13 healthy donors were collected alongside 15 ALK-positive tumor tissue and 10 healthy lung tissue specimens. All plasma and tissue samples were analyzed by cell-free DNA methylation immunoprecipitation sequencing to generate genome-wide 5-mC profiles. Information on genomic alterations (i.e., somatic mutations/fusions and copy number alterations) determined in matched plasma samples was available from previous studies.

RESULTS

We devised a strategy that identified tumor-specific 5-mC biomarkers by reducing 5-mC background signals derived from hematopoietic cells. This was followed by differential methylation analysis (cases vs. controls) and biomarker validation using 5-mC profiles of ALK-positive tumor tissues. The resulting 245 differentially methylated regions were enriched for lung adenocarcinoma-specific 5-mC patterns in TCGA data and indicated transcriptional repression of several genes described to be silenced in NSCLC (e.g., PCDH10, TBX2, CDO1, and HOXA9). Additionally, 5-mC-based tumor DNA (5-mC score) was highly correlated with other genomic alterations in cell-free DNA (Spearman, ρ > 0.6), while samples with high 5-mC scores showed significantly shorter overall survival (log-rank p = 0.025). Longitudinal 5-mC scores reflected radiologic disease assessments and were significantly elevated at disease progression compared to the therapy start (p = 0.0023). In 7 out of 8 instances, rising 5-mC scores preceded imaging-based evaluation of disease progression.

CONCLUSION

We demonstrated a strategy to identify 5-mC biomarkers from the plasma of cancer patients and integrated them into a quantitative measure of cancer-associated 5-mC alterations. Using longitudinal plasma samples of ALK-positive NSCLC patients, we highlighted the suitability of cfDNA methylation for prognosis and therapy monitoring.

Analysis of m6A modulator-mediated methylation modification patterns and the tumor microenvironment in lung adenocarcinoma

Lung adenocarcinoma (LUAD) is the most common histological subtype of lung cancer. In the development and progression of LUAD, epigenetic aberration plays a crucial role. However, the function of RNA N6-methyladenosine (m⁶A) modifications in the LUAD progression is unknown. The m6A regulator modification patterns in 955 LUAD samples were analyzed comprehensively. Patterns were systematically correlated with the tumor microenvironment (TME) cell-infiltration characteristics. Using principal component analysis algorithms, the m6Ascore was generated to quantify m⁶A modification patterns in individual tumors. Then, their values for predicting prognoses and therapeutic response in LUAD patients were assessed. Three distinct m⁶A modification patterns in LUAD were identified. Among them, the prognosis of m6Acluster C was the best, while the prognosis of m⁶Acluster A was the worst. Interestingly, the characterization of TME cell infiltration and biological behavior differed among the three patterns. To evaluate m⁶A modification patterns within individual tumors, an m⁶Ascore signature was constructed. The results showed that the high m⁶Ascore group was associated with a better prognosis; tumor somatic mutations and tumor microenvironment differed significantly between the high- and low- m⁶Ascore groups. Furthermore, in the cohort with anti-CTLA-4 treatment alone, patients with a high m⁶Ascore had higher ICI scores, which indicated significant therapeutic advantage and clinical benefits.

The function and clinical implication of circular RNAs in lung cancer

Lung cancer is the leading cause of cancer-related deaths worldwide. Despite the recent advent of promising new targeted therapies, lung cancer diagnostic strategies still have difficulty in identifying the disease at an early stage. Therefore, the characterizations of more sensible and specific cancer biomarkers have become an important goal for clinicians. Circular RNAs are covalently close, endogenous RNAs without 5' end caps or 3'poly (A) tails and have been characterized by high stability, abundance, and conservation as well as display cell/tissue/developmental stage-specific expressions. Numerous studies have confirmed that circRNAs act as microRNA (miRNA) sponges, RNA-binding protein, and transcriptional regulators; some circRNAs even act as translation templates that participate in multiple pathophysiological processes. Growing evidence have confirmed that circRNAs are involved in the pathogenesis of lung cancers through the regulation of proliferation and invasion, cell cycle, autophagy, apoptosis, stemness, tumor microenvironment, and chemotherapy resistance. Moreover, circRNAs have emerged as potential biomarkers for lung cancer diagnosis and prognosis and targets for developing new treatments. In this review, we will summarize recent progresses in identifying the biogenesis, biological functions, potential mechanisms, and clinical applications of these molecules for lung cancer diagnosis, prognosis, and targeted therapy.

Downregulation of PRMT5 by AMI-1 enhances therapeutic efficacy of compound kushen injection in lung carcinoma in vitro and in vivo

Protein arginine methyltransferase 5 (PRMT5) is overexpressed in lung carcinoma, which promotes tumor cell proliferation, survival, migration and invasion. Compound Kushen injection (CKI) is a mixture of natural compounds extracted from Kushen and Baituling, which are mainly used to stop in cancer pain and bleeding. Here we found that cell viability and colony formation were inhibited after the incubation of AMI-1. Meanwhile, AMI-1 suppressed cell migration, enhanced apoptosis, induced cell cycle arrest, inhibited PRMT5 expression and histone H3R8 and H4R3 symmetric di-methylation (H3R8me2s and H4R3me2s) accumulation, down-regulated the expression of eukaryotic translation initiation factor 4E (eIF4E) in lung carcinoma cells. Moreover, AMI-1 suppressed tumor growth, decreased H3R8me2s and H4R3me2s accumulation, down-regulated eIF4E expression and increased p53 expression in lung carcinoma xenografts of BALB/c nude mice. Of note, combined and CKI markedly enhanced the anticancer efficacy CKI in lung carcinoma. The above findings demonstrated that AMI-1 has established antineoplastic activity and this role may be associated with affecting the function of eIF4E via inhibiting PRMT5 activity or protein levels in lung carcinoma. This study highlights evidence of novel selective anticancer activity of AMI-1 in combination with CKI in lung carcinoma.

Identification of Prognostic Genes and Immune Landscape Signatures Based on Tumor Microenvironment in Lung Adenocarcinoma

Background

Lung adenocarcinoma is the most common lung cancer subtype and accounts for the highest proportion of cancer-related deaths. The tumor microenvironment influences prognostic outcomes in lung adenocarcinoma (LUAD).

Materials and Methods

We used the ESTIMATE algorithm (Estimation of STromal and Immune cells in MAlignant Tumor tissues using Expression data) to investigate the role of microenvironment-related genes and stromal cells in lung adenocarcinoma prognosis. This analysis was done on lung adenocarcinoma cases from The Cancer Genome Atlas (TCGA). The cases were divided into high and low groups on the basis of immune and stromal scores, respectively.

Results

There were close correlations between immune scores with prognosis and disease stage. There were 367 differentially expressed genes. Combining the Gene Expression Omnibus (GEO) database, we found 14 prognosis-related genes.

Results

There were close correlations between immune scores with prognosis and disease stage. There were 367 differentially expressed genes. Combining the Gene Expression Omnibus (GEO) database, we found 14 prognosis-related genes. Results. Based on the enrichment levels of the immune cell types, we clustered LUAD into Immunity_H and Immunity_L subtypes. Most of these genes were upregulated in Immunity_H subtype. Finally, using the Human Protein Atlas (HPA) and the Clinical Proteomic Tumor Analysis Consortium (CPTAC) databases, most of the proteins corresponding to prognostic genes were verified to be differentially expressed between the tumor and normal groups.

Conclusions

The key genes identified in this study are involved in molecular mechanisms of LUAD.

Design and experimental validation of OPERA_MET-A panel for deep methylation analysis by next generation sequencing

DNA methylation is the most recognized epigenetic mark that leads to a massive distortion in cancer cells. It has been observed that a large number of DNA aberrant methylation events occur simultaneously in a group of genes, thus providing a growth advantage to the cell in promoting cell differentiation and neoplastic transformation. Due to this reason, methylation profiles have been suggested as promising cancer biomarkers. Here, we designed and performed a first step of validation of a novel targeted next generation sequencing (NGS) panel for methylation analysis, which can simultaneously evaluate the methylation levels at CpG sites of multiple cancer-related genes. The OPERA_MET-A methylation panel was designed using the Ion AmpliSeq™ technology to amplify 155 regions with 125-175 bp mean length and covers a total of 1107 CpGs of 18 cancer-related genes. The performance of the panel was assessed by running commercially available fully methylated and unmethylated control human genomic DNA (gDNA) samples and a variable mixture of them. The libraries were run on Ion Torrent platform and the sequencing output was analyzed using the “methylation_analysis” plugin. DNA methylation calls on both Watson (W) and Crick (C) strands and methylated:unmethylated ratio for each CpG site were obtained. Cell lines, fresh frozen and formalin-fixed paraffin-embedded (FFPE) lung cancer tissues were tested. The OPERA_MET-A panel allows to run a minimum of 6 samples/530 chip to reach an observed mean target depth ≥2,500X (W and C strands) and an average number of mapped reads >750,000/sample. The conversion efficiency, determined by spiking-in unmethylated Lambda DNA into each sample before the bisulfite conversion process, was >97% for all samples. The observed percentage of global methylation for all CpGs was >95% and <5% for fully methylated and unmethylated gDNA samples, respectively, and the observed results for the variable mixtures were in agreement with what was expected. Methylation-specific NGS analysis represents a feasible method for a fast and multiplexed screening of cancer patients by a high-throughput approach. Moreover, it offers the opportunity to construct a more robust algorithm for disease prediction in cancer patients having a low quantity of biological material available.

The effects of valproic acid on skin healing: experimental study in rats

Purpose:

To recognize the effects of valproic acid (VPA), an epigenetic drug, on the skin healing process.

Methods:

Sixty male Wistar rats were divided into two groups: the experiment treated with VPA (100 mg/kg/day); and the control, with 0.9% sodium chloride by gavage. Skin healing was studied in three moments (the third, the seventh, and the 14th day), evaluating the parameters: inflammatory reaction and its intensity (anti-LCA), angiogenesis (anti-CD34), collagen I and III (anti-collagen I, anti-collagen III and Picrosirius-red F3BA) and myofibroblasts (anti-alpha-AMS).

Results:

The inflammatory reaction was acute or sub-acute in both groups on the third day. On the seventh and the 14th day, chronic predominated in the control (p=0.006), and sub-acute in the experiment (p=0.020). There was a greater number of leukocytes in the group treated only on the third day (p=0.036). The number of vessels was lower in the treated group at the three times (p3=0.002, p7<0.001, and p14=0.027). Myofibroblasts were rare in the third day and moderate quantity in the remaining periods. Collagen I density was higher in the control at the three times (p<0.001) and collagen III in the treated group (p<0.001).

Conclusions:

VPA led to a more intense inflammatory reaction, decreased angiogenesis and collagen deposition, especially type I collagen.

Photodynamic Effects of Thuja occidentalis on Lung Cancer Cells

The global incidence and mortality rates resulting from lung cancer encapsulate a need to identify more effective treatment protocols. Photodynamic therapy (PDT) and homeopathy offer possible anticancer therapies as part of a multi-disciplinary approach. Studies have identified the anticancer effects of Thuja occidentalis L. plant extracts. The aim of this study was to investigate the effects of Thuja occidentalis (TO) homeopathic mother tincture and TO mediated PDT (TO-PDT) on A549 lung cancer cells. Commercially available A549 cells were pre-treated with TO, or laser irradiation at 660 nm, or the combined treatment (TO-PDT). Cells were analyzed morphologically by inverted light microscopy and Hoechst stain; and biochemically by lactate dehydrogenase (LDH), adenosine triphosphate (ATP), and trypan blue assays. Cells treated with TO and TO-PDT demonstrated morphological changes in the cell and cell nuclei indicative of cell death. These groups exhibited a dose dependent increase in LDH release and a decrease in ATP levels and cell viability indicating its cytotoxic and antiproliferative potential. Furthermore, at the same doses, TO when photoactivated in PDT induced enhanced anticancer responses thereby surpassing the effects of treatment with the tincture alone. Results demonstrate how the direct cytotoxic effects of TO can be improved when administered as a photosensitizer in PDT to promote cancer cell death.

Pan-cancer landscape of the RUNX protein family reveals their potential as carcinogenic biomarkers and the mechanisms underlying their action

Background

The RUNX family of transcription factors plays an important regulatory role in tumor development. Although the importance of RUNX in certain cancer types is well known, the pan-cancer landscape remains unclear.

Materials and Methods

Data from The Cancer Genome Atlas (TCGA) provides a pan-cancer overview of the RUNX genes. Hence, herein, we performed a pan-cancer analysis of abnormal RUNX expression and deciphered the potential regulatory mechanism. Specifically, we used TCGA multi-omics data combined with multiple online tools to analyze transcripts, genetic alterations, DNA methylation, clinical prognoses, miRNA networks, and potential target genes.

Results

RUNX genes are consistently overexpressed in esophageal, gastric, pancreatic, and pan-renal cancers. The total protein expression of RUNX1 in lung adenocarcinoma, kidney renal clear cell carcinoma (KIRC), and uterine corpus endometrial carcinoma (UCEC) is consistent with the mRNA expression results. Moreover, increased phosphorylation on the T14 and T18 residues of RUNX1 may represent potential pathogenic factors. The RUNX genes are significantly associated with survival in pan-renal cancer, brain lower-grade glioma, and uveal melanoma. Meanwhile, various mutations and posttranscriptional changes, including the RUNX1 D96 mutation in invasive breast carcinoma, the co-occurrence of RUNX gene mutations in UCEC, and methylation changes in the RUNX2 promoter in KIRC, may be associated with cancer development. Finally, analysis of epigenetic regulator co-expression, miRNA networks, and target genes revealed the carcinogenicity, abnormal expression, and direct regulation of RUNX genes.

Conclusions

We successfully analyzed the pan-cancer abnormal expression and prognostic value of RUNX genes, thereby providing potential biomarkers for various cancers. Further, mutations revealed via genetic alteration analysis may serve as a basis for personalized patient therapies.

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.

Signal pathways and precision therapy of small-cell lung cancer

Small-cell lung cancer (SCLC) encounters up 15% of all lung cancers, and is characterized by a high rate of proliferation, a tendency for early metastasis and generally poor prognosis. Most of the patients present with distant metastatic disease at the time of clinical diagnosis, and only one-third are eligible for potentially curative treatment. Recently, investigations into the genomic make-up of SCLC show extensive chromosomal rearrangements, high mutational burden and loss-of-function mutations of several tumor suppressor genes. Although the clinical development of new treatments for SCLC has been limited in recent years, a better understanding of oncogenic driver alterations has found potential novel targets that might be suitable for therapeutic approaches. Currently, there are six types of potential treatable signaling pathways in SCLC, including signaling pathways targeting the cell cycle and DNA repair, tumor development, cell metabolism, epigenetic regulation, tumor immunity and angiogenesis. At this point, however, there is still a lack of understanding of their role in SCLC tumor biology and the promotion of cancer growth. Importantly optimizing drug targets, improving drug pharmacology, and identifying potential biomarkers are the main focus and further efforts are required to recognize patients who benefit most from novel therapies in development. This review will focus on the current learning on the signaling pathways, the status of immunotherapy, and targeted therapy in SCLC.

Histone H3K9 methyltransferase SETDB1 augments invadopodia formation to promote tumor metastasis

Non-small cell lung cancer (NSCLC) is one of leading causes of cancer-related mortality worldwide, which harbors various accumulated genetic and epigenetic abnormalities. Histone methyltransferase SETDB1 is a pivotal epigenetic regulator whose focal amplification and upregulation are commonly detected in NSCLC. However, molecular mechanisms underlying the pro-oncogenic function of SETDB1 remain poorly characterized. Here, we demonstrate that SETDB1 augments the migration and invasion capabilities of NSCLC cells by reinforcing invadopodia formation and mediated ECM degradation. At the molecular level, SETDB1 suppresses the expression of FOXA2, a crucial tumor and metastasis suppressor via coordinated epigenetic mechanisms - SETDB1 not only catalyzes histone H3K9 methylation on FOXA2 genomic locus, but also recruits DNMT3A to regulate DNA methylation on CpG island. Consequently, depletion of Setdb1 in murine lung adenocarcinoma cells completely abolished their full and spontaneous metastatic capabilities in mouse xenograft models. These findings together establish the pro-metastasis activity of SETDB1 in NSCLC and elucidate the underlying cellular and molecular mechanisms.

Long Non-Coding RNA AP000695.2 Acts as a Novel Prognostic Biomarker and Regulates the Cell Growth and Migration of Lung Adenocarcinoma

Long non-coding RNAs (lncRNAs) are tumor-associated biological molecules and have been found to be implicated in the progression of lung adenocarcinoma (LUAD). LncRNA-AP000695.2 (ENSG00000248538) is a long non-coding RNA (lncRNA) that is widely increased in many tumor types including lung adenocarcinoma (LUAD). However, the aberrant expression profile, clinical significance, and biological function of AP000695.2 in human lung adenocarcinoma (LUAD) need to be further investigated. This study mines key prognostic AP000695.2 and elucidates its potential role and molecular mechanism in regulating the proliferation and metastasis of LUAD. Here, we discovered that AP000695.2 was significantly upregulated in lung adenocarcinoma tissues compared with healthy adjacent lung tissue and higher in LUAD cell lines than in normal human bronchial epithelial cell lines. A higher expression of AP000695.2 was positively correlated with aggressive clinicopathological characteristics, and AP000695.2 served as an independent prognostic indicator for the overall survival, disease-free survival, and progression-free survival in patients with LUAD. Receiver operating curve (ROC) analysis revealed the significant diagnostic ability of AP000695.2 (AUC = 0.838). Our in vivo data confirmed that AP000695.2 promotes the proliferation, migration, and invasion of LUAD cells. GSEA results suggested that AP000695.2 co-expressed genes were mainly enriched in immune-related biological processes such as JAK-STAT signaling pathway and toll-like receptor signaling pathway. Single-sample GSEA analysis showed that AP000695.2 is correlated with tumor-infiltrating immune cells in lung adenocarcinoma. Our findings confirmed that AP000695.2 was involved in the progression of lung adenocarcinoma, providing a novel prognostic indicator and promising diagnostic biomarker in the future.

Identification of novel natural inhibitors targeting AKT Serine/Threonine Kinase 1 (AKT1) by computational study

Despite great progress, the current cancer treatments often have obvious toxicity and side effects. and a poor prognosis (some patients). One of the reasons for the poor prognosis is that certain enzymes prevent anticancer drugs from killing tumor cells. AKT1 is involved in regulating PI3K/AKT/mTOR, a tumor-generating pathway. Ipatasertib, a highly selective inhibitor of AKT1, is widely used in the treatment of tumors. In this study, many structural and biochemical methodswere used to find better AKT1(Threonine Kinase 1) inhibitors, which laid a foundation for the further development of AKT1 inhibitors and provided new drugs for the treatment of tumors. ZINC15 database and Discovery Studio 4.5, a computer-aided drug screening software with many modules (LibDock for virtual screening, ADME (Absorption, Distribution, Metabolism, Excretion) and TOPKAT (toxicity prediction module) for the toxicity and properties analysis, and MD simulation for stability prediction), were employed. CCK8 assay, ELISA assay genicity and higher tolerance to cytochrome P4502D6. MD simulations indicated they could bind with AKT1 stably in the natural environment. The cell experiment and specific assay for AKT1 inhibition showed they could inhibit the proliferation and AKT1 expression of MG63 cells (Osteosarcoma cells). Moreover, these novel compounds with structural modifications can be potential contributors that lead to further rational drug design for targeting AKT1.

AbbreviationAKT1, AKT Serine/Threonine Kinase 1; ADME, absorption, distribution, metabolism, excretion; TOPKAT, toxicity prediction by Computer assisted technology; CCK8, Cell Counting Kit 8; ELISA, Enzyme-linked immunosorbent assay; CYP2D6, cytochrome P4502D6 inhibition; GBM, Glioblastoma; AGC kinase, protein kinase A, G, and C families (PKA, PKC, PKG); PKB, protein kinase B; PAM pathway, PI3K/AKT/mTOR pathway; OS, overall survival; PFS, progression-free survival; LD50, lethal dose half in rats; LOAEL, lowest observed adverse effect level; NPT, normal pressure and temperature; PME, particle mesh Ewald; LINCS, linear constraint solver; RMSD, root-mean-square deviation; BBB, blood–brain barrier; DS, Discovery Studio; DTP, Developmental toxicity potential; PPB, Plasma protein binding; MTD, Maximum Tolerated Dosage; AB, Aerobic Biodegradability; NTP, US. National Toxicology Program; DTP, developmental toxicity potential.

Artificial neural network in the discrimination of lung cancer based on infrared spectroscopy

Given the increasing prevalence of lung cancer worldwide, an auxiliary diagnostic method is needed alongside the microscopic examination of biopsy samples, which is dependent on the skills and experience of pathologists. Thus, this study aimed to advance lung cancer diagnosis by developing five (5) artificial neural network (NN) models that can discriminate malignant from benign samples based on infrared spectral data of lung tumors (n = 122; 56 malignant, 66 benign). NNs were benchmarked with classical machine learning (CML) models. Stratified 10-fold cross-validation was performed to evaluate the NN models, and the performance metrics—area under the curve (AUC), accuracy (ACC) positive predictive value (PPV), negative predictive value (NPV), specificity rate (SR), and recall rate (RR)—were averaged for comparison. All NNs were able to outperform the CML models, however, support vector machine is relatively comparable to NNs. Among the NNs, CNN performed best with an AUC of 92.28% ± 7.36%, ACC of 98.45% ± 1.72%, PPV of 96.62% ± 2.30%, NPV of 90.50% ± 11.92%, SR of 96.01% ± 3.09%, and RR of 89.21% ± 12.93%. In conclusion, NNs can be potentially used as a computational tool in lung cancer diagnosis based on infrared spectroscopy of lung tissues.

Joint Effects of Cigarette Smoking and Green Tea Consumption with miR-29b and DNMT3B mRNA Expression in the Development of Lung Cancer

In tumor development, increased expression of DNA methyltransferase (DNMT) has been observed. In particular, cigarette smoke and tea polyphenols may influence DNMT3B mRNA expression by regulating microRNA (miR)-29b expression. Herein, we designed a case−control study to evaluate the joint effects of smoking and green tea consumption, with miR-29b and DNMT3B mRNA expression, in lung cancer development. A total of 132 lung cancer patients and 132 healthy controls were recruited to measure miR-29b and DNMT3B mRNA expression in whole blood. Results revealed that lung cancer patients had lower miR-29b expression (57.2 vs. 81.6; p = 0.02) and higher DNMT3B mRNA expression (37.2 vs. 25.8; p < 0.001) than healthy controls. Compared to non-smokers with both higher miR-29b and lower DNMT3B mRNA expression, smokers with both low miR-29b and higher DNMT3B mRNA expression had an elevated risk of lung cancer development (OR 5.12, 95% CI 2.64−9.91). Interactions of smoking with miR-29b or DNMT3B mRNA expression in lung cancer were significant. Interaction of green tea consumption with miR-29b expression and DNMT3B mRNA expression in lung cancer was also significant. Our study suggests that smokers and green tea nondrinkers with lower miR-29b expression and higher DNMT3B mRNA expression are more susceptible to lung cancer development.