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Decellularized extracellular matrix is one form of natural material in tissue engineering. The process of dECM retains the tissue microstructure, provides good cell adhesion sites, maintains most of biological signals that promotes the survival and differentiation ability of cells. In this study, sheep kidney was decellularized followed by histochemical staining, elemental analysis and scanning electron microscopy characterizations. The dECM scaffold was prepared with different sequences of freeze drying technology, crosslinking and the water absorption, porosity, mechanical strength with subsequent thermogravimetric analysis, Infrared spectroscopy and biocompatibility tests. Our results indicated that these decellularized treatments of sheep kidney can effectively remove DNA and retain uniform pore size distribution. After crosslinking the scaffold’s water absorption decreased from 987.56 ± 40.21% to 934.39 ± 39.61%, the porosity decreased from 89.64 ± 3.2% to 85.09 ± 17.63%, and the compression modulus increased from 304.32 ± 25.43 kPa to 459.53 ± 38.92 kPa, with thermal process the percentage of weight loss decreased from 66.57% to 44.731%, in addition, the composition didn’t change significantly, crosslinking could also promote the stability. In terms of biocompatibility, the number of viable cells increased significantly with the days. In conclusion, the crosslinked decellularized sheep kidney extracellular matrix scaffold reduced water absorption and porosity slightly, but has a significant increase in mechanical properties, and presented excellent biocompatibility which are beneficial to cell adhesion, growth and differentiation.

The skin plays an important role in vitamin D synthesis, humoral balance, temperature regulation, and waste excretion. Due to the complexity of the skin, fluids loss, bacterial infection, and other life-threatening secondary complications caused by skin defects often lead to the damage of skin functions. 3D bioprinting technology, as a customized and precise biomanufacturing platform, can manufacture dressings and tissue engineering scaffolds that accurately simulate tissue structure, which is more conducive to wound healing. In recent years, with the development of emerging technologies, an increasing number of 3D-bioprinted wound dressings and skin tissue engineering scaffolds with multiple functions, such as antibacterial, anti-inflammatory, antioxidant, hemostatic, and antitumor properties, have significantly improved wound healing and skin treatment. In this article, we review the process of wound healing and summarize the classification of 3D bioprinting technology. Following this, we shift our focus on the functional materials for wound dressing and skin tissue engineering, and also highlight the research progress and development direction of 3D-bioprinted multifunctional wound healing materials.

Severe skin injuries can cause serious problems, which could affect the patient’s normal life, if not dealt properly in a timely and effective manner. It is an urgent requirement to develop personalized wound dressings with excellent antibacterial activity and biocompatibility to match the shape of the wound to facilitate clinical application. In this study, a bioink (GAQ) based on gelatin (Gel)/sodium alginate (SA)/ quaternized chitosan (QCS) was prepared, and GAQ hydrogel dressing grafting with dopamine (GADQ) was fabricated by an extrusion three-dimensional (3D) printing technology. QCS was synthesized by modifying quaternary ammonium group on chitosan, and its structure was successfully characterized by nuclear magnetic resonance (1H NMR) and Fourier-transform infrared spectroscopy (FT-IR). Our results showed that the GADQ hydrogel dressing that was double-crosslinked by EDC/ NHS and Ca2+ had good tensile strength, considerable swelling ratio, and effective antioxidation properties. It also showed that GADQ1.5% had 93.17% and 91.06% antibacterial activity against Staphylococcus aureus and Escherichia coli, respectively. Furthermore, the relative survival ratios of fibroblast cells seeded on these hydrogels exceeded 350% after cultured for 7 days, which proved the biocompatibility of these hydrogels. Overall, this advanced 3D-printed GADQ1.5% hydrogels with effective antioxidation, excellent antibacterial activity and good biocompatibility had a considerable application potential for wound healing.

Pleural mesothelioma (PM) is a highly aggressive, fast-growing asbestos-induced cancer with limited effective treatments. There has been an interest in using naturally occurring anticancer agents derived from plant materials for the treatment of PM. However, it is unclear if aqueous extract from theLeptospermum polygalifolium(QV0) has activity against PM. Here we investigated the anti-cancer property of QV0in vitroandin vivo.Animals treated with Defender®(QV0 dietary supply) exhibited a reduced tumour size over 30 days, which was associated with an average extended of seven days mouse life. There was no liver toxicity, nor increased blood glucose post-treatment in animals treated with Defender®. Moreover, QV0 suppressed the growth of 13 cancer cell lines in a dose-dependent manner, effective at concentrations as low as 0.02% w/v. This response was found to be associated with inhibited cell migration, proliferation, and colony formation, but without evident cell cycle alteration. We observed mitochondrial dysfunction post QV0 treatment, as evidenced by significantly decreased basal and maximal oxygen consumption rates. Significantly enhanced tumour apoptosis was observed in the Defender®-treated animals, correlating with mitochondrial dysfunction. To the best of our knowledge, this study constitutes the first demonstration of an improved host survival (without adverse effects) response in a QV0-treated PM mouse model, associated with an evident inhibition of PM cell growth and mitochondrial dysfunction-related enhancement of tumour apoptosis.ImportanceA major problem with cancer chemotherapy or immunotherapy is the severe adverse effects associated with normal tissue damage. PM is known to be treatment resistant and has poor a prognosis, therefore new therapeutic treatment options are urgently needed. In the present study, we explored the potential utility of aLeptospermumextract (QV0) as a treatment option for mesothelioma. We demonstrated for the first time that QV0 exhibits an anti-tumour response in mesothelioma, without any associated adverse effects observed in the PM mouse model. These findings provide a rationale for early-stage clinical trials. We anticipate that prospective translational research will lead to the clinical implementation of a novel QV0-based treatment strategy that will ultimately benefit PM patients.

Microrobots can expand our abilities to access remote, confined, and enclosed spaces. Their potential applications inside our body are obvious, e.g., to diagnose diseases, deliver medicine, and monitor treatment efficacy. However, critical requirements exist in relation to their operations in gastrointestinal environments, including resistance to strong gastric acid, responsivity to a narrow proton variation window, and locomotion in confined cavities with hierarchical terrains. Here, we report a proton-activatable microrobot to enable real-time, repeated, and site-selective pH sensing and monitoring in physiological relevant environments. This is achieved by stratifying a hydrogel disk to combine a range of functional nanomaterials, including proton-responsive molecular switches, upconversion nanoparticles, and near-infrared (NIR) emitters. By leveraging the 3D magnetic gradient fields and the anisotropic composition, the microrobot can be steered to locomote as a gyrating "Euler's disk", i.e., aslant relative to the surface and along its low-friction outer circumference, exhibiting a high motility of up to 60 body lengths/s. The enhanced magnetomotility can boost the pH-sensing kinetics by 2-fold. The fluorescence of the molecular switch can respond to pH variations with over 600-fold enhancement when the pH decreases from 8 to 1, and the integration of upconversion nanoparticles further allows both the efficient sensitization of NIR light through deep tissue and energy transfer to activate the pH probes. Moreover, the embedded down-shifting NIR emitters provide sufficient contrast for imaging of a single microrobot inside a live mouse. This work suggests great potential in developing multifunctional microrobots to perform generic site-selective tasks in vivo.

Malignant pleural mesothelioma (MPM) is a rare, aggressive cancer of the lung lining that is predominantly associated with occupational exposure to asbestos. MPM is responsible for thousands of deaths worldwide every year, with the median survival of MPM of 8–14 months. There are limited biomarkers available in the clinic to effectively diagnose MPM, an invasive biopsy procedure is usually required to provide a definitive diagnosis. Due to the long latency period associated with MPM disease presentation, the cancer is usually at an advanced stage at the time of diagnosis where treatment options are largely ineffective at controlling disease progression. Previous MPM-based pre-clinical studies have made significant strides in determining the exact molecular mechanisms associated with asbestos carcinogenesis. Exploring less invasive blood-based biomarkers and treatment strategies involving targeted therapy, immunotherapy, and virotherapy is particularly important. Research in these areas is of crucial importance in relation to improving the rate of novel diagnostic biomarkers and treatment strategies progressing through to clinical trials and ultimately into the clinical setting. This review comprehensively summarises both previous and current pre-clinical research developments that have specifically contributed to an improved understanding of MPM disease biology, and the development of novel diagnostic biomarkers and treatment strategies.

Tissue-engineered scaffolds are more commonly used to construct three-dimension­al (3D) tumor models for in vitro studies when compared to the conventional two-dimensional (2D) cell culture because the microenvironments provided by the 3D tumor models closely resemble the in vivo system and could achieve higher success rate when the scaffolds are translated for use in pre-clinical animal model. Physical properties, heterogeneity, and cell behaviors of the model could be regulated to simulate different tumors by changing the components and concentrations of materials. In this study, a novel 3D breast tumor model was fabricated by bioprinting using a bioink that consists of porcine liver-derived decellularized extracellular matrix (dECM) with different concentrations of gelatin and sodium alginate. Primary cells were removed while extracellular matrix components of porcine liver were preserved. The rheolog­ical properties of biomimetic bioinks and the physical properties of hybrid scaffolds were investigated, and we found that the addition of gelatin increased hydrophilia and viscoelasticity, while the addition of alginate increased mechanical properties and porosity. The swelling ratio, compression modulus, and porosity could reach 835.43 ± 130.61%, 9.64 ± 0.41 kPa, and 76.62 ± 4.43%, respectively. L929 cells and the mouse breast tumor cells 4T1 were subsequently inoculated to evaluate biocompatibility of the scaffolds and to form the 3D models. The results showed that all scaffolds exhibited good biocompatibility, and the average diameter of tumor spheres could reach 148.52 ± 8.02 μm on 7 d. These findings suggest that the 3D breast tumor model could serve as an effective platform for anticancer drug screening and cancer research in vitro.

Delayed wound healing is one of the most global public health threats affecting nearly 100 million people each year, particularly the chronic wounds. Many confounding factors such as aging, diabetic disease, medication, peripheral neuropathy, immunocompromises or arterial and venous insufficiency hyperglycaemia are considered to inhibit wound healing. Therapeutic approaches for slow wound healing include anti-infection, debridement and the use of various wound dressings. However, the current clinical outcomes are still unsatisfied. In this review, we discuss the role of skin and wound commensal microbiota in the different healing stages, including inflammation, cell proliferation, re-epithelialization and remodelling phase, followed by multiple immune cell responses to commensal microbiota. Current clinical management in treating surgical wounds and chronic wounds was also reviewed together with potential controlled delivery systems which may be utilized in the future for the topical administration of probiotics and microbiomes. This review aims to introduce advances, novel strategies, and pioneer ideas in regulating the wound microbiome and the design of controlled delivery systems.

The last few decades have brought tremendous advances in the mechanisms of epigenetic regulation, with DNA methylation, histone methylation and acetylation, microRNAs and other noncoding RNAs being among the most prominent [...]

Carbon nanotubes (CNTs), as kinds of conductive carbon nanomaterials, were widely applied in neural tissue engineering due to their excellent electrical conductivity and good biocompatibility. In this study, the carboxyl-modified multi-walled carbon nanotubes (mMWCNTs) were introduced into sodium alginate/gelatin (Alg/Gel) scaffolds to optimize the function of the hybrid scaffolds. The Alg/Gel/mMWCNTs conductive scaffolds with mMWCNTs content of 1%, 3%, and 5% were prepared by freeze-drying, respectively. Following this, the physicochemical properties and biocompatibility of the hybrid scaffolds at different magnetic field intensities were evaluated. The conductive scaffolds were characterized by Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). In general, the mMWCNTs addition improved the hydrophilic, electrical conductivity and mechanical properties of the composite scaffold, and PC12 cells showed a trend of gradual increase over culture time. Particularly, the Alg/Gel-1%C scaffold exhibited the best cell proliferation behavior. Briefly, the surface contact angle decreased from 74 ± 1° to 60 ± 3°, the electrical conductivity and compressive modulus increased to 1.32 × 10

Currently, a suitable bioink for 3D bioprinting and capable of mimicking the microenvironment of native skin and preventing bacterial infection remains a major challenge in skin tissue engineering. In this study, we prepared a tissue-specific extracellular matrix-based bioink, and dECM/Gel/QCS (dGQ) 3D scaffold assembling with poly(ionic liquid)s (PILs) (dGQP) was obtained by an extrusion 3D bioprinting technology and dynamic hydrogen bonding method. The morphologies, mechanical properties, porosity, hydrophilicity, biodegradation, hemostatic effect, antibacterial ability, and biocompatibility of the hybrid scaffolds were characterized and evaluated. Results showed that the rapid release (2 h) of PILs on the dGQP scaffold can quickly kill gram-negative (E. coli) and gram-positive (S. aureus) bacteria with almost 100 % antibacterial activity and maintained a stable sterile environment for a long time (7 d), which was superior to the dGQ scaffold. The hemostasis and hemolysis test showed that the dGQP scaffold had a good hemostatic effect and excellent hemocompatibility. In vitro cytocompatibility studies showed that although the cell growth on dGQP scaffold was slow in the early stage, the cells proliferated rapidly since day 4 and had high ECM secretion at day 7. Overall, this advanced dGQP scaffold has a considerable potential to be applied in skin tissue engineering.

Craniofacial bone regeneration is a coupled process of angiogenesis and osteogenesis, which, associated with infection, still remains a challenge in bone defects after trauma or tumor resection. 3D tissue engineering scaffolds with multifunctional-therapeutic properties can offer many advantages for the angiogenesis and osteogenesis of infected bone defects. Hence, in the present study, a microchannel networks-enriched 3D hybrid scaffold composed of decellularized extracellular matrix (dECM), gelatin (Gel), quaterinized chitosan (QCS) and nano-hydroxyapatite (nHAp) (dGQH) was fabricated by an extrusion 3D bioprinting technology. And enlightened by the characteristics of natural bone microstructure and the demands of vascularized bone regeneration, the exosomes (Exos) isolated from human adipose derived stem cells as angiogenic and osteogenic factors were then co-loaded into the desired dGQH20 hybrid scaffold based on an electrostatic interaction. The results of the hybrid scaffolds performance characterization showed that these hybrid scaffolds exhibited an interconnected pore structure and appropriate degradability (>61% after 8 weeks of treatment), and the dGQH20 hybrid scaffold displayed the highest porosity (83.93 ± 7.38%) and mechanical properties (tensile modulus: 62.68 ± 10.29 MPa, compressive modulus: 16.22 ± 3.61 MPa) among the dGQH hybrid scaffolds. Moreover, the dGQH20 hybrid scaffold presented good antibacterial activities (against 94.90 ± 2.44% of Escherichia coli and 95.41 ± 2.65% of Staphylococcus aureus, respectively) as well as excellent hemocompatibility and biocompatibility. Furthermore, the results of applying the Exos to the dGQH20 hybrid scaffold showed that the Exo promoted the cell attachment and proliferation on the scaffold, and also showed a significant increase in osteogenesis and vascularity regeneration in the dGQH@Exo scaffolds in vitro and in vivo. Overall, this novel dECM/Gel/QCS/nHAp hybrid scaffold laden with Exo has a considerable potential application in reservation of craniofacial bone defects.

Wound healing is a complex process involving multiple independent and overlapping sequential physiological mechanisms. In addition to cutaneous injury, a severe burn stimulates physiological derangements that induce a systemic hypermetabolic response resulting in impaired wound healing. Topical application of the anti-androgen drug, flutamide accelerates cutaneous wound healing, whereas paradoxically systemic dihydrotestosterone (DHT) improves burn wound healing. We developed and characterized a PCL scaffold that is capable of controlled release of androgen (DHT) and anti-androgen (F) individually or together. This study aims to investigate whether local modification of androgen actions has an impact on burn injury wound healing. In a full-thickness burn wound healing, mouse model, DHT/F-scaffold showed a significantly faster wound healing compared with F-scaffold or DHT-scaffold. Histology analysis confirmed that DHT/F-scaffold exhibited higher re-epithelization, cell proliferation, angiogenesis, and collagen deposition. Dual release of DHT and F from PCL scaffolds promoted cell proliferation of human keratinocytes and alters the keratinocyte cell cycle. Lastly, no adverse effects on androgen-dependent organs, spleen and liver were observed. In conclusion, we demonstrated DHT plus F load PCL scaffolds accelerated burn wound healing when loading alone did not. These findings point to a complex role of androgens in burn wound healing and open novel therapeutic avenues for treating severe burn patients.

Compared with conventional therapeutic approaches, nanomedicines are attracting a growing interest due to their better targeting ability, higher delivery efficiency, and good water solubility. However, conventional drug efficacy assessment methods are based on a two-dimensional (2D) culture approach of single cells to obtain in vitro therapeutic effects, which may not be representative of actual tumors. Based on the above considerations, the three-dimensional (3D) cell culture models became a better choice since they can increase the complexity of in vitro systems and provide a biomimetic microenvironment that is closer to the in vivo native than 2D cultures. In our study, curcumin nanoparticle (CurNPs) with good water solubility and good tumor therapeutic effects were prepared by combining polymeric non-ionic surfactant (Pluronic F127) with curcumin. The hybrid scaffolds based on nano-clay, sodium alginate, and gelatin were also prepared, which showed good printability and excellent biocompatibility. We then studied the therapeutic effects of CurNPs on metastatic breast cancer using a 3D tumor model fabricated with scaffold-bound metastatic breast cancer (MDA-MB-231) cells. It was showed that the 3D cell model presented better cell proliferation effect while compared with 2D version. Additionally, there was good enhanced permeability and retention effect when CurNPs entered with better accumulate in 3D cell ‘tumor’ sites which represented more realistic response of a more real tumor treatment effect for breast cancer cells. Our study indicated that the combinational of nanomaterials with 3D cell ‘tumor’ models provided an alternative and better platform for drug screening and has great potential be used as safe and effective treatment screening for breast cancer.

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

Antibiotic resistance has been a global threat to public health. Majority of antibiotics kill bacteria by inducing the DNA damage. However, bacteria can repair DNA damage via a series of intrinsic pathways including the SOS response. The master regulator of the SOS response is RecA, which was shown to be involved in an enhanced evolution of resistance to fluoroquinolone. Until very recently, the relationship between the evolution of β-lactam resistance and the SOS response remains undefined. Here, we find a superfast evolution of β-lactam resistance (20-fold MIC) following the deletion of RecA in Escherichia coli and treatment with a single dose of β-lactams in 8 hours. Importantly, once this type of resistance being established, it was stable and heritable. Controversially to previous findings, our results indicate this process is completely orthogonal to the SOS response but dependent on the hindrance of DNA repair. In addition, we observe explosive appearance of drug-specific mutations of the bacterial genome in 8 hours of exposure to ampicillin, such as the acrB mutations which is responsible for multi-drug resistance. Together, these findings demonstrate that hindrance of DNA repair not only generally antagonizes cells fitness, but also provides bacteria with genetic plasticity to adapt to diverse stressful environments and can dramatically accelerates the evolution of antibiotic resistance in DNA repair deficiency cells.ImportanceThe evolution of antibiotic resistance can be induced by long-term exposure to antibiotics. However, we for the first time report a superfast evolution of multi-drug resistance induced by a single treatment with β-lactam in DNA repair deficiency Escherichia coli. More importantly, this type of evolutionary trajectory can cause a more rapid spread of drug-resistant bacteria in the community, because once the resistance being established, it was stable and heritable. In addition, from a clinical perspective, our finding significantly highlights the possibility that the synergistic drug combination between β-lactam and inhibitors targeting DNA repair system especially in the patients with cancer treatment can lead to a superfast evolution of multi-drug resistance.

Microrobots can expand our abilities to access remote, confined, and enclosed spaces. Their potential applications inside our body are obvious

Colorectal cancer (CRC) is a leading cancer globally; therefore, early diagnosis and surveillance of this cancer are of paramount importance. Current methods of CRC diagnosis rely heavily on endoscopy or radiological imaging. Noninvasive tests including serum detection of the carcinoembryonic antigen (CEA) and faecal occult blood testing (FOBT) are associated with low sensitivity and specificity, especially at early stages. DNA methylation biomarkers have recently been found to have higher accuracy in CRC detection and enhanced prediction of prognosis and chemotherapy response. The most widely studied biomarker in CRC is methylated septin 9 (SEPT9), which is the only FDA-approved methylation-based biomarker for CRC. Apart from SEPT9, other methylated biomarkers including tachykinin-1 (TAC1), somatostatin (SST), and runt-related transcription factor 3 (RUNX3) have been shown to effectively detect CRC in a multitude of sample types. This review will discuss the performances of various methylated biomarkers used for CRC diagnosis and monitoring, when used alone or in combination.

We are pleased to announce the publication of this Research Topic focusing on epigenetic modifications in mesothelioma. Epigenetic modification has been investigated for the past two decades. It is a key process of cellular development as well as carcinogenesis. Mesothelioma is an aggressive cancer caused by asbestos exposure and currently has very limited effective treatment options. Epigenetic modification in mesothelioma is an emerging field which will provide fundamental information for diagnosis and treatment of mesothelioma. We believe that, as for other cancers, if we can detect this cancer at an as early stage as possible, then we can significantly increase survival time as well as select suitable treatments for the patients. Currently, misdiagnosis and delayed treatment jeopardises patient survival and quality of life. Mesothelioma is one of the most difficult cancers to diagnose, due to symptoms closely resembling lung cancer and other lung diseases. The most discussed topics in this Research Topic are biomarkers and how to diagnose mesothelioma. Rozitis et al. discuss the current methods used to diagnose mesothelioma. The take home message of this review is that at least nine immunohistochemistry biomarkers are used in the clinical setting to facilitate mesothelioma diagnosis. A tissue or cytology sample is normally required for definitive diagnosis. The authors mention the necessity to further develop epigenetic biomarkers to facilitate clinical diagnosis. A novel class of biomarker - the “circular RNA” is also discussed in the review. The review provides the basis of how mesothelioma is currently diagnosed and reviews emerging epigenetic biomarkers in mesothelioma. Although DNA methylation is the most discussed epigenetic biomarker in other cancers, microRNA represents the most interesting for mesothelioma researchers. Tomasetti et al. focus on microRNA as an early diagnosis biomarker for mesothelioma. The authors cover how reactive oxygen species (ROS) induced from asbestos can cause epigenetic alterations and aberrant gene expression. MicroRNAs are stable and amenable for treatment development. Unlike protein-coding genes in gene replacement therapy, microRNAs are small and more easily to restore their “cancer killer” functions. More importantly, the authors discuss microRNA replacement therapy in mesothelioma for which there has been one on-going clinical trial. We believe this review will trigger further development of microRNA replacement to treat mesothelioma. Biomarkers that facilitate other treatment options leading to better outcomes in mesothelioma are another emerging area of discussion. Yoshikawa et al. research the benefits of epigenetic alterations and its potential in advancing the response to immune checkpoint PD-1 inhibitor nivolumab. The authors describe recent knowledge on epigenetic alterations, which identify potential candidate therapeutic targets and immunotherapeutic regimens under development for MPM. Being a disease that is difficult to diagnose, researchers have tried various biomarkers that are anticipated to improve mesothelioma diagnosis. CDKN2A fluorescence in-situ hybridization is one of the biomarkers used in a clinical setting to facilitate differential mesothelioma diagnosis. Cheng et al. re-validate CDKN2A and MTAP, which are usually co-deleted in mesothelioma, in a large cohort of MPM patient samples. The authors promote the use of droplet digital PCR (ddPCR) as an alternative to study these two biomarkers in mesothelioma. Amongst all the epigenetic biomarkers discussed in the special edition, circulating biomarker is frequently explored because of its advantage in requiring less-invasive detection routes. With the development of new detection methods, biomarkers that provide high sensitivity and specificity can easily be further investigated for their clinical applications. Epigenetic biomarkers such as DNA methylation, microRNA and non-coding RNA have high potential to provide sensitive and specific detection of mesothelioma as well as providing earlier possible detection. Epigenetic regulation is a rewarding area of study, as it is involved in almost all developmental processes including the early stage of cancers. Different epigenetic signatures can be used to identify different stages of cancer development. This makes it relatively useful for further development for early detection of mesothelioma. Due to a long latency period from asbestos exposure to development of mesothelioma, most patients are diagnosed at a late stage of the disease when very limited treatment options are available for effective outcomes. Early detection utilizing epigenetic biomarkers to identify mesothelioma will be beneficial for this deadly disease. Epigenetic biomarkers have great potential to become more conclusive diagnostic and prognostic biomarkers for mesothelioma. The development of new technologies will also largely facilitate biomarker detection sensitivity. However, further research is required in this field to ensure the widespread application of epigenetic biomarkers in clinical settings. In conclusion, epigenetic regulation plays a major role in mesothelioma and holds great potential to become clinically relevant in mesothelioma. More studies are required to further develop and validate the clinical applications of epigenetic biomarkers in mesothelioma.

Malignant pleural mesothelioma (MPM) is an aggressive malignancy with limited effective treatment options. Focal adhesion kinase (FAK) inhibitors have been shown to efficiently suppress MPM cell growth initially, with limited utility in the current clinical setting. In this study, we utilised a large collection of MPM cell lines and MPM tissue samples to study the role of E-cadherin (CDH1) and microRNA on the efficacy of FAK inhibitors in MPM. The immunohistochemistry (IHC) results showed that the majority of MPM FFPE samples exhibited either the absence of, or very low, E-cadherin protein expression in MPM tissue. We showed that MPM cells with high CDH1 mRNA levels exhibited resistance to the FAK inhibitor PND-1186. In summary, MPM cells that did not express CDH1 mRNA were sensitive to PND-1186, and MPM cells that retained CDH1 mRNA were resistant. A cell cycle analysis showed that PND-1186 induced cell cycle disruption by inducing the G2/M arrest of MPM cells. A protein−protein interaction study showed that EGFR is linked to the FAK pathway, and a target scan of the microRNAs revealed that microRNAs (miR-17, miR221, miR-222, miR137, and miR148) interact with EGFR 3′UTR. Transfection of MPM cells with these microRNAs sensitised the CHD1-expressing FAK-inhibitor-resistant MPM cells to the FAK inhibitor.

MicroRNAs (miRNAs) are short, non-coding RNAs that regulate gene expression at a posttranscriptional level. Each miRNA controls the expression of multiple messenger RNAs (mRNAs) and their dysregulation has been implicated in multiple cancer phenotypes. While some miRNAs are upregulated, global downregulation of miRNA expression is often the rule in cancer. A multitude of potential mechanisms drive aberrant miRNA expression in cancer; miRNA coding regions can harbour genomic defects including mutations, amplifications or deletions, and some miRNAs are broadly repressed by transcription factors such as Myc or have epigenetic modifications to their promoter regions such as hypermethylation of CpG islands. Additionally, the suppression of components of the miRNA processing machinery has been shown to reduce mature miRNA expression and contribute to the malignant phenotype. Understanding the mechanisms driving miRNA downregulation is important in uncovering the critical and complex role of miRNAs in cancer biology. This review will outline the multiple mechanisms by which cancer cells suppress miRNA expression.

In light of the high incidence and mortality rates of cancer, early and accurate diagnosis is an important priority for assigning optimal treatment for each individual with suspected illness. Biomarkers are crucial in the screening of patients with a high risk of developing cancer, diagnosing patients with suspicious tumours at the earliest possible stage, establishing an accurate prognosis, and predicting and monitoring the response to specific therapies. Epigenetic alterations are innovative biomarkers for cancer, due to their stability, frequency, and noninvasive accessibility in bodily fluids. Epigenetic modifications are also reversible and potentially useful as therapeutic targets. Despite this, there is still a lack of accurate biomarkers for the conclusive diagnosis of most cancer types; thus, there is a strong need for continued investigation to expand this area of research. In this review, we summarise current knowledge on methylated DNA and its implications in cancer to explore its potential as an epigenetic biomarker to be translated for clinical application. We propose that the identification of biomarkers with higher accuracy and more effective detection methods will enable improved clinical management of patients and the intervention at early-stage disease.

With the increasing incidence and mortality of colorectal cancer (CRC), early and accurate diagnosis is of paramount priority to combat this cancer. Epigenetic alterations such as DNA methylation are innovative biomarkers for CRC, due to their stability, frequency, and accessibility in bodily fluids. In this study, blood samples were prospectively collected from patients before and after operation for CRC for determination of methylated septin 9 (mSEPT9) and compared to carcinoembryonic antigen (CEA). The sensitivity of using mSEPT9 methylation status for diagnosing CRC was significantly higher than using elevated CEA levels (73.2% vs 48.2%; p value

MicroRNA downregulation is frequent in malignant pleural mesothelioma (MPM), but the mechanisms responsible for loss of miR-15/16 and miR-193a are yet to be elucidated and were investigated in this study. Copy Number Variation (CNV) of microRNA-coding genes was analyzed in MPM cells by digital droplet PCR (ddPCR) and revealed heterozygous loss of miR-193a and miR-15a/16-1, but no change in miR-15b/16-2. Epigenetic control of microRNA expression was inferred following decitabine and Trichostatin A (TSA) treatment which did not substantially affect microRNA expression. Knockdown of c-Myc expression led to upregulation of SMC4, miR-15b and 16, and to a lesser extent DLEU2 and miR-15a, whereas c-Myc overexpression repressed microRNA expression. Chromatin immunoprecipitation (ChIP) assays confirmed the interaction of c-Myc with the DLEU2 and SMC4 promoters. Tumor microRNA expression was determined in samples from MPM patients, with samples of pleura from cardiac surgery patients used as controls. In tumor samples, a strong correlation was observed between the expression of miR-15b and 16 (R2=0.793), but not miR-15a and 16. Our data suggest that in MPM, the downregulation of miR-15/16 is due to transcriptional repression by c-Myc, primarily via control of the miR-15b/16-2 locus, while miR-193a-3p loss is due to genomic deletion.

Malignant pleural mesothelioma (MPM) is a deadly cancer that is caused by asbestos exposure and that has limited treatment options. The current standard of MPM diagnosis requires the testing of multiple immunohistochemical (IHC) markers on formalin-fixed paraffin-embedded tissue to differentiate MPM from other lung malignancies. To date, no single biomarker exists for definitive diagnosis of MPM due to the lack of specificity and sensitivity; therefore, there is ongoing research and development in order to identify alternative biomarkers for this purpose. In this study, we utilized primary MPM cell lines and tested the expression of clinically used biomarker panels, including CK8/18, Calretinin, CK 5/6, CD141, HBME-1, WT-1, D2-40, EMA, CEA, TAG72, BG8, CD15, TTF-1, BAP1, and Ber-Ep4. The genomic alteration of CDNK2A and BAP1 is common in MPM and has potential diagnostic value. Changes in CDKN2A and BAP1 genomic expression were confirmed in MPM samples in the current study using Fluorescence In situ Hybridization (FISH) analysis or copy number variation (CNV) analysis with digital droplet PCR (ddPCR). To determine whether MPM tissue and cell lines were comparable in terms of molecular alterations, IHC marker expression was analyzed in both sample types. The percentage of MPM biomarker levels showed variation between original tissue and matched cells established in culture. Genomic deletions of BAP1 and CDKN2A, however, showed consistent levels between the two. The data from this study suggest that genomic deletion analysis may provide more accurate biomarker options for MPM diagnosis.

Malignant pleural mesothelioma (MPM) is a deadly cancer that is caused by asbestos exposure and that has limited treatment options. The current standard of MPM diagnosis requires the testing of multiple immunohistochemical (IHC) markers on formalin-fixed paraffin-embedded tissue to differentiate MPM from other lung malignancies. To date, no single biomarker exists for definitive diagnosis of MPM due to the lack of specificity and sensitivity; therefore, there is ongoing research and development in order to identify alternative biomarkers for this purpose. In this study, we utilized primary MPM cell lines and tested the expression of clinically used biomarker panels, including CK8/18, Calretinin, CK 5/6, CD141, HBME-1, WT-1, D2-40, EMA, CEA, TAG72, BG8, CD15, TTF-1, BAP1, and Ber-Ep4. The genomic alteration of CDNK2A and BAP1 is common in MPM and has potential diagnostic value. Changes in CDKN2A and BAP1 genomic expression were confirmed in MPM samples in the current study using Fluorescence In situ Hybridization (FISH) analysis or copy number variation (CNV) analysis with digital droplet PCR (ddPCR). To determine whether MPM tissue and cell lines were comparable in terms of molecular alterations, IHC marker expression was analyzed in both sample types. The percentage of MPM biomarker levels showed variation between original tissue and matched cells established in culture. Genomic deletions of BAP1 and CDKN2A, however, showed consistent levels between the two. The data from this study suggest that genomic deletion analysis may provide more accurate biomarker options for MPM diagnosis.

Malignant pleural mesothelioma (MPM) is an asbestos-induced cancer with poor prognosis that displays characteristic alterations in microRNA expression. Recently it was reported that the expression of a subset of microRNAs can distinguish between MPM and adenocarcinoma of the lung. However, the functional importance of these changes has yet to be investigated. We compared expression of miR-192, miR-193a-3p and the miR-200 family in normal pleura and MPM tumor specimens and found a statistically significant reduction in the levels of miR-193a-3p (3.1-fold) and miR-192 (2.8-fold) in MPM. Transfection of MPM cells with a miR-193a-3p mimic resulted in inhibition of growth and an induction of apoptosis and necrosis in vitro. The growth inhibitory effects of miR-193a-3p were associated with a decrease in MCL1 expression and were recapitulated by RNAi-mediated MCL1 silencing. Targeted delivery of miR-193a-3p mimic using EDV minicells inhibited MPM xenograft tumour growth, and was associated with increased apoptosis. In conclusion, miR-193a-3p appears to have importance in the biology of MPM and may represent a target for therapeutic intervention.