Tumour predisposition and cancer syndromes as models to study gene-environment interactions

Peripheral blood DNA methylation profiles predict future development of B-cell Non-Hodgkin Lymphoma

Lack of accurate methods for early lymphoma detection limits the ability to cure patients. Since patients with Non-Hodgkin lymphomas (NHL) who present with advanced disease have worse outcomes, accurate and sensitive methods for early detection are needed to improve patient care. We developed a DNA methylation-based prediction tool for NHL, based on blood samples collected prospectively from 278 apparently healthy patients who were followed for up to 16 years to monitor for NHL development. A predictive score was developed using machine learning methods in a robust training/validation framework. Our predictive score incorporates CpG DNA methylation at 135 genomic positions, with higher scores predicting higher risk. It was 85% and 78% accurate for identifying patients at risk of developing future NHL, in patients with high or low epigenetic mitotic clock respectively, in a validation cohort. It was also sensitive at detecting active NHL (96.3% accuracy) and healthy status (95.6% accuracy) in additional independent cohorts. Scores optimized for specific NHL subtypes showed significant but lower accuracy for predicting other subtypes. Our score incorporates hyper-methylation of Polycomb and HOX genes, which have roles in NHL development, as well as PAX5 - a master transcriptional regulator of B-cell fate. Subjects with higher risk scores showed higher regulatory T-cells, memory B-cells, but lower naïve T helper lymphocytes fractions in the blood. Future prospective studies will be required to confirm the utility of our signature for managing patients who are at high risk for developing future NHL.

Diagnostics of BAP1-Tumor Predisposition Syndrome by a Multitesting Approach: A Ten-Year-Long Experience

Germline mutations in the tumor suppressor gene BRCA1-associated protein-1 (BAP1) lead to BAP1 tumor predisposition syndrome (BAP1-TPDS), characterized by high susceptibility to several tumor types, chiefly melanoma, mesothelioma, renal cell carcinoma, and basal cell carcinoma. Here, we present the results of our ten-year experience in the molecular diagnosis of BAP1-TPDS, along with a clinical update and cascade genetic testing of previously reported BAP1-TPDS patients and their relatives. Specifically, we sequenced germline DNA samples from 101 individuals with suspected BAP1-TPDS and validated pathogenic variants (PVs) by assessing BAP1 somatic loss in matching tumor specimens. Overall, we identified seven patients (7/101, 6.9%) carrying six different germline BAP1 PVs, including one novel variant. Consistently, cascade testing revealed a total of seven BAP1 PV carriers. In addition, we explored the mutational burden of BAP1-TPDS tumors by targeted next-generation sequencing. Lastly, we found that certain tumors present in PV carriers retain a wild-type BAP1 allele, suggesting a sporadic origin of these tumors or a functional role of heterozygous BAP1 in neoplastic development. Altogether, our findings have important clinical implications for therapeutic response of BAP1-TPDS patients.

ROS-Related miRNAs Regulate Immune Response and Chemoradiotherapy Sensitivity in Hepatocellular Carcinoma by Comprehensive Analysis and Experiment

Reactive oxygen species (ROS) plays an essential role in the development of cancer. Here, we chose ROS-related miRNAs for consensus clustering analysis and ROS score construction. We find that ROS is extremely associated with prognosis, tumor immune microenvironment (TIME), gene mutations, N6-methyladenosine (m6A) methylation, and chemotherapy sensitivity in hepatocellular carcinoma (HCC). Mechanistically, ROS may affect the prognosis of HCC patients in numerous ways. Moreover, miR-210-3p and miR-106a-5p significantly increased the ROS level and stagnated cell cycle at G2/M in HCC; the results were more obvious in cells after ionizing radiation (IR). Finally, the two miRNAs suppressed cell proliferation, migration, and invasion and promoted apoptosis in huh7 and smmc7721 cells. It indicated that ROS might affect the prognosis of HCC patients through immune response and increase the sensitivity of HCC patients to radiotherapy and chemotherapy.

Epigenetic Inheritance: Intergenerational Effects of Pesticides and Other Endocrine Disruptors on Cancer Development

Parental environmental experiences affect disease susceptibility in the progeny through epigenetic inheritance. Pesticides are substances or mixtures of chemicals-some of which are persistent environmental pollutants-that are used to control pests. This review explores the evidence linking parental exposure to pesticides and endocrine disruptors to intergenerational and transgenerational susceptibility of cancer in population studies and animal models. We also discuss the impact of pesticides and other endocrine disruptors on the germline epigenome as well as the emerging evidence for how epigenetic information is transmitted between generations. Finally, we discuss the importance of this mode of inheritance in the context of cancer prevention and the challenges ahead.

Age of first cancer diagnosis and survival in Bloom syndrome

PURPOSE

This study aimed to describe the spectrum of cancers observed in Bloom Syndrome and the observed survival and age of first cancer diagnosis in Bloom syndrome as these are not well-defined.

METHODS

Data from the Bloom Syndrome Registry (BSR) was used for this study. Cancer history, ages of first cancer diagnosis, and ages of death were compiled from the BSR and analyzed.

RESULTS

Among the 290 individuals in the BSR, 155 (53%) participants developed 251 malignant neoplasms; 100 (65%) were diagnosed with 1 malignancy, whereas the remaining 55 (35%) developed multiple malignancies. Of the 251 neoplasms, 83 (33%) were hematologic and 168 (67%) were solid tumors. Hematologic malignancies (leukemia and lymphoma) were more common than any of the solid tumors. The most commonly observed solid tumors were colorectal, breast, and oropharyngeal. The cumulative incidence of any malignancy by age 40 was 83%. The median survival for all participants in the BSR was 36.2 years. There were no significant differences in time to first cancer diagnosis or survival by genotype among the study participants.

CONCLUSION

We describe the spectrum of cancers observed in Bloom syndrome and the observed survival and age of first cancer diagnosis in Bloom syndrome. We also highlight the significant differences in survival and age of diagnosis seen among different tumor types and genotypes.

Therapeutic targeting of BAP1/ASXL3 sub-complex in ASCL1-dependent small cell lung cancer

Small cell lung cancer (SCLC) is an aggressive disease, with patients diagnosed with either early-stage, limited stage, or extensive stage of SCLC tumor progression. Discovering and targeting the functional biomarkers for SCLC will be crucial in understanding the molecular basis underlying SCLC tumorigenesis to better assist in improving clinical treatment. Emerging studies have demonstrated that dysregulations in BAP1 histone H2A deubiquitinase complex are collectively associated with pathogenesis in human SCLC. Here, we investigated the function of the oncogenic BAP1/ASXL3/BRD4 epigenetic axis in SCLC by developing a next-generation BAP1 inhibitor, iBAP-II, and focusing on the epigenetic balance established between BAP1 and non-canonical PRC1 complexes in regulating SCLC-specific transcriptional programming. We further demonstrated that pharmacologic inhibition of BAP1’s catalytic activity disrupted BAP1/ASXL3/BRD4 epigenetic axis by inducing protein degradation of the ASXL3 scaffold protein, which bridges BRD4 and BAP1 at active enhancers. Furthermore, treatment of iBAP-II represses neuroendocrine lineage-specific ASCL1/MYCL/E2F signaling in SCLC cell lines, and dramatically inhibits SCLC cell viability and tumor growth in vivo. In summary, this study has provided mechanistic insight into the oncogenic function of BAP1 in SCLC and highlighted the potential of targeting BAP1’s activity as a novel SCLC therapy.

Analysis of cancer omics data: a selective review of statistical techniques

Cancer is an omics disease. The development in high-throughput profiling has fundamentally changed cancer research and clinical practice. Compared with clinical, demographic and environmental data, the analysis of omics data-which has higher dimensionality, weaker signals and more complex distributional properties-is much more challenging. Developments in the literature are often 'scattered', with individual studies focused on one or a few closely related methods. The goal of this review is to assist cancer researchers with limited statistical expertise in establishing the 'overall framework' of cancer omics data analysis. To facilitate understanding, we mainly focus on intuition, concepts and key steps, and refer readers to the original publications for mathematical details. This review broadly covers unsupervised and supervised analysis, as well as individual-gene-based, gene-set-based and gene-network-based analysis. We also briefly discuss 'special topics' including interaction analysis, multi-datasets analysis and multi-omics analysis.

Molecular Pathogenesis of Colorectal Cancer with an Emphasis on Recent Advances in Biomarkers, as Well as Nanotechnology-Based Diagnostic and Therapeutic Approaches

Colorectal cancer (CRC) is a serious disease that affects millions of people throughout the world, despite considerable advances in therapy. The formation of colorectal adenomas and invasive adenocarcinomas is the consequence of a succession of genetic and epigenetic changes in the normal colonic epithelium. Genetic and epigenetic processes associated with the onset, development, and metastasis of sporadic CRC have been studied in depth, resulting in identifying biomarkers that might be used to predict behaviour and prognosis beyond staging and influence therapeutic options. A novel biomarker, or a group of biomarkers, must be discovered in order to build an accurate and clinically useful test that may be used as an alternative to conventional methods for the early detection of CRC and to identify prospective new therapeutic intervention targets. To minimise the mortality burden of colorectal cancer, new screening methods with higher accuracy and nano-based diagnostic precision are needed. Cytotoxic medication has negative side effects and is restricted by medication resistance. One of the most promising cancer treatment techniques is the use of nano-based carrier system as a medication delivery mechanism. To deliver cytotoxic medicines, targeted nanoparticles might take advantage of differently expressed molecules on the surface of cancer cells. The use of different compounds as ligands on the surface of nanoparticles to interact with cancer cells, enabling the efficient delivery of antitumor medicines. Formulations based on nanoparticles might aid in early cancer diagnosis and help to overcome the limitations of traditional treatments, including low water solubility, nonspecific biodistribution, and restricted bioavailability. This article addresses about the molecular pathogenesis of CRC and highlights about biomarkers. It also provides conceptual knowledge of nanotechnology-based diagnostic techniques and therapeutic approaches for malignant colorectal cancer.

Gene by Environment Interactions reveal new regulatory aspects of signaling network plasticity

Phenotypes can change during exposure to different environments through the regulation of signaling pathways that operate in integrated networks. How signaling networks produce different phenotypes in different settings is not fully understood. Here, Gene by Environment Interactions (GEIs) were used to explore the regulatory network that controls filamentous/invasive growth in the yeast Saccharomyces cerevisiae. GEI analysis revealed that the regulation of invasive growth is decentralized and varies extensively across environments. Different regulatory pathways were critical or dispensable depending on the environment, microenvironment, or time point tested, and the pathway that made the strongest contribution changed depending on the environment. Some regulators even showed conditional role reversals. Ranking pathways' roles across environments revealed an under-appreciated pathway (OPI1) as the single strongest regulator among the major pathways tested (RAS, RIM101, and MAPK). One mechanism that may explain the high degree of regulatory plasticity observed was conditional pathway interactions, such as conditional redundancy and conditional cross-pathway regulation. Another mechanism was that different pathways conditionally and differentially regulated gene expression, such as target genes that control separate cell adhesion mechanisms (FLO11 and SFG1). An exception to decentralized regulation of invasive growth was that morphogenetic changes (cell elongation and budding pattern) were primarily regulated by one pathway (MAPK). GEI analysis also uncovered a round-cell invasion phenotype. Our work suggests that GEI analysis is a simple and powerful approach to define the regulatory basis of complex phenotypes and may be applicable to many systems.

BAP1 forms a trimer with HMGB1 and HDAC1 that modulates gene × environment interaction with asbestos

Carriers of heterozygous germline BAP1 mutations (BAP1 ^+/-) are affected by the "BAP1 cancer syndrome." Although they can develop almost any cancer type, they are unusually susceptible to asbestos carcinogenesis and mesothelioma. Here we investigate why among all carcinogens, BAP1 mutations cooperate with asbestos. Asbestos carcinogenesis and mesothelioma have been linked to a chronic inflammatory process promoted by the extracellular release of the high-mobility group box 1 protein (HMGB1). We report that BAP1 ^+/- cells secrete increased amounts of HMGB1, and that BAP1 ^+/- carriers have detectable serum levels of acetylated HMGB1 that further increase when they develop mesothelioma. We linked these findings to our discovery that BAP1 forms a trimeric protein complex with HMGB1 and with histone deacetylase 1 (HDAC1) that modulates HMGB1 acetylation and its release. Reduced BAP1 levels caused increased ubiquitylation and degradation of HDAC1, leading to increased acetylation of HMGB1 and its active secretion that in turn promoted mesothelial cell transformation.

Durvalumab with platinum-pemetrexed for unresectable pleural mesothelioma: survival, genomic and immunologic analyses from the phase 2 PrE0505 trial

Mesothelioma is a rare and fatal cancer with limited therapeutic options until the recent approval of combination immune checkpoint blockade. Here we report the results of the phase 2 PrE0505 trial (NCT02899195) of the anti-PD-L1 antibody durvalumab plus platinum-pemetrexed chemotherapy for 55 patients with previously untreated, unresectable pleural mesothelioma. The primary endpoint was overall survival compared to historical control with cisplatin and pemetrexed chemotherapy; secondary and exploratory endpoints included safety, progression-free survival and biomarkers of response. The combination of durvalumab with chemotherapy met the pre-specified primary endpoint, reaching a median survival of 20.4 months versus 12.1 months with historical control. Treatment-emergent adverse events were consistent with known side effects of chemotherapy, and all adverse events due to immunotherapy were grade 2 or lower. Integrated genomic and immune cell repertoire analyses revealed that a higher immunogenic mutation burden coupled with a more diverse T cell repertoire was linked to favorable clinical outcome. Structural genome-wide analyses showed a higher degree of genomic instability in responding tumors of epithelioid histology. Patients with germline alterations in cancer predisposing genes, especially those involved in DNA repair, were more likely to achieve long-term survival. Our findings indicate that concurrent durvalumab with platinum-based chemotherapy has promising clinical activity and that responses are driven by the complex genomic background of malignant pleural mesothelioma.

In a phase 2 trial, the combination of chemotherapy with durvalumab, an anti-PD-L1 antibody, exhibited promising clinical activity in patients with previously untreated, unresectable mesothelioma, with additional analyses providing insights into genomic and immunologic features potentially associated with response.

Lack of Association between Common Polymorphisms in Selenoprotein P Gene and Susceptibility to Colorectal Cancer, Breast Cancer, and Prostate Cancer: A Meta-Analysis

Method

We search the PubMed, Embase, Google Scholar, and Wanfang (China) databases (up to December 1, 2020) to identify all eligible publications. The pooled odds ratio (OR) correspondence with 95% confidence interval (CI) was calculated to evaluate the associations.

Results

Finally, nine eligible studies with 7,157 cases and 6,440 controls and five studies with 2,278 cases and 2,821 controls were enrolled in rs3877899 and rs7579 polymorphisms, individually. However, a null significant association was detected between the two polymorphisms in SEPP1 and susceptibility to colorectal, breast, and prostate cancer in all comparison models. Subsequently, subgroup analysis based on tumor type, no significant association was identified for prostate, breast, and colorectal cancer. In addition, when the stratification analyses were conducted by the source of control, HWE status, and ethnicity, yet no significant association was found.

Conclusions

The current meta-analysis shows that SEPP1 rs3877899 and rs7579 polymorphisms may not be associated with susceptibility to colon cancer, breast cancer, and prostate cancer, and further well-designed studies with a larger sample size are warranted to validate our findings.

Aberrant expression of MYD88 via RNA-controlling CNOT4 and EXOSC3 in colonic mucosa impacts generation of colonic cancer

In 2020, the worldwide incidence and mortality of colorectal cancer (CRC) were third and second, respectively. As the 5‐y survival rate is low when CRC is diagnosed at an advanced stage, a reliable method to predict CRC susceptibility is important for preventing the onset and development and improving the prognosis of CRC. Therefore, we focused on the normal colonic mucosa to investigate changes in gene expression that may induce subsequent genetic alterations that induce malignant transformation. Comprehensive gene expression profiling in the normal mucosa adjacent to colon cancer (CC) compared with tissue from non‐colon cancer patients was performed. PCR arrays and qRT‐PCR revealed that the expression of 5 genes involved in the immune response, including MYD88, was increased in the normal mucosa of CC patients. The expression levels of MYD88 were strikingly increased in precancerous normal mucosa specimens, which harbored no somatic mutations, as shown by immunohistochemistry. Microarray analysis identified 2 novel RNA‐controlling molecules, EXOSC3 and CNOT4, that were significantly upregulated in the normal mucosa of CC patients and were clearly visualized in the nuclei. Forced expression of EXOSC3 and CNOT4 in human colonic epithelial cells increased the expression of IFNGR1, MYD88, NFκBIA, and STAT3 and activated ERK1/2 and JNK in 293T cells. Taken together, these results suggested that, in the inflamed mucosa, EXOSC3‐ and CNOT4‐mediated RNA stabilization, including that of MYD88, may trigger the development of cancer and can serve as a potential predictive marker and innovative treatment to control cancer development.

Biological basis for novel mesothelioma therapies

Mesothelioma is an aggressive cancer that is associated with exposure to asbestos. Although asbestos is banned in several countries, including the UK, an epidemic of mesothelioma is predicted to affect middle-income countries during this century owing to their heavy consumption of asbestos. The prognosis for patients with mesothelioma is poor, reflecting a failure of conventional chemotherapy that has ultimately resulted from an inadequate understanding of its biology. However, recent work has revolutionised the study of mesothelioma, identifying genetic and pathophysiological vulnerabilities, including the loss of tumour suppressors, epigenetic dysregulation and susceptibility to nutrient stress. We discuss how this knowledge, combined with advances in immunotherapy, is enabling the development of novel targeted therapies.

Asbestos-induced chronic inflammation in malignant pleural mesothelioma and related therapeutic approaches-a narrative review

Objective:

The aim of this review is addressing the mechanisms of asbestos carcinogenesis, including chronic inflammation and autophagy-mediated cell survival, and propose potential innovative therapeutic targets to prevent mesothelioma development or improve drug efficacy by reducing inflammation and autophagy.

Background:

Diffuse malignant pleural mesothelioma is an aggressive cancer predominantly related to chronic inflammation caused by asbestos exposure. Millions of individuals have been exposed to asbestos or to other carcinogenic mineral fibers occupationally or environmentally, resulting in an increased risk of developing mesothelioma. Overall patient survival rates are notably low (about 8–14 months from the time of diagnosis) and mesothelioma is resistant to existing therapies. Additionally, individuals carrying inactivating germline mutations in the BRCA-associated protein 1 (BAP1) gene and other genes are predisposed to developing cancers, prevalently mesothelioma. Their risk of developing mesothelioma further increases upon exposure to asbestos. Recent studies have revealed the mechanisms and the role of inflammation in asbestos carcinogenesis. Biomarkers for asbestos exposure and malignant mesothelioma have also been identified. These findings are leading to the development of novel therapeutic approaches to prevent or delay the growth of mesothelioma.

Methods:

Review of full length manuscripts published in English from January 1980 to February 2021 gathered from PubMed.gov from the National Center of Biotechnology Information and the National Library of Medicine were used to inform this review.

Conclusion:

Key regulators of chronic inflammation mediate asbestos-driven mesothelial cell transformation and survival through autophagic pathways. Recent studies have elucidated some of the key mechanisms involved in asbestos-induced chronic inflammation, which are largely driven by extracellular high mobility group box 1 (HMGB1). Upon asbestos exposure, mesothelial cells release HMGB1 from the nucleus to the cytoplasm and extracellular space, where HMGB1 initiates an inflammatory response. HMGB1 translocation and release also activates autophagy and other pro-survival mechanisms, which promotes mesothelioma development. HMGB1 is currently being investigated as a biomarker to detect asbestos exposure and to detect mesothelioma development in its early stage when therapy is more effective. In parallel, several approaches inhibiting HMGB1 activities have been studied and have shown promising results. Moreover, additional cytokines, such as IL-1β and TNF-α are being targeted to interfere with the inflammatory process that drives mesothelioma growth. Developing early detection methods and novel therapeutic strategies is crucial to prolong overall survival of patients with mesothelioma. Novel therapies targeting regulators of asbestos-induced inflammation to reduce mesothelioma growth may lead to clinical advancements to benefit patients with mesothelioma.

Distinctive Prognostic Value and Cellular Functions of Osteopontin Splice Variants in Human Gastric Cancer

Background: Osteopontin (OPN) splice variants are identified as predictors of tumour progression and therapeutic resistance in certain types of solid tumours. However, their roles in gastric cancer (GC) remain poorly characterized. The current study sought to assess the prognostic value of the three OPN splice variants (namely OPN-a, OPN-b, and OPN-c) in gastric cancer and their potential functions within gastric cancer cells. Methods: RNA extraction and reverse transcription were performed using our clinical cohort of gastric carcinomas and matched normal tissues (n = 324 matched pairs). Transcript levels were determined using real-time quantitative PCR. Three OPN splice variants overexpressed cell lines were created from the gastric cancer cell line HGC-27. Subsequently, biological functions, including cell growth, adhesion, migration, and invasion, were studied. The potential effects of OPN isoforms on cisplatin and 5-Fu were evaluated by detecting cellular reactive oxygen species (ROS) levels in the HGC-27-derived cell lines. Results: Compared with normal tissues, the expression levels of three splice variants were all elevated in gastric cancer tissues in an order of OPN-a > OPN-b > OPN-c. The OPN-a level significantly increased with increasing TNM staging and worse clinical outcome. There appeared to be a downregulation for OPN-c in increasing lymph node status (p < 0.05), increasing TNM staging, and poor differentiation. High levels of OPN-a and OPN-b were correlated with short overall survival and disease-free survival of gastric cancer patients. However, the low expression of OPN-c was significantly associated with a poor prognosis. Functional analyses further showed that ectopic expression of OPN-c suppressed in vitro proliferation, adhesiveness, migration, and invasion properties of HGC-27 cells, while the opposite role was seen for OPN-a. Cellular ROS detection indicated that OPN-a and OPN-c significantly promoted ROS production after treatment with 5-Fu comparing to OPN-vector, while only OPN-a markedly induced ROS production after treatment with cisplatin. Conclusion: Our results suggest that OPN splice variants have distinguished potential to predict the prognosis of gastric cancer. Three OPN variants exert distinctive functions in gastric cancer cells. Focusing on specific OPN isoforms could be a novel direction for developing diagnostic and therapeutic approaches in gastric cancer.

Associations of individual and joint expressions of ERCC6 and ERCC8 with clinicopathological parameters and prognosis of gastric cancer

Background

Excision repair cross-complementing group 6 and 8 (ERCC6 and ERCC8) have been implicated in ailments such as genetic diseases and cancers. However, the relationship between individual and joint expressions of ERCC6/ERCC8 and clinicopathological parameters as well as prognosis of gastric cancer (GC) still remains unclear.

Methods

In this study, protein expressions of ERCC6, ERCC8 and ERCC6-ERCC8 were detected by immunohistochemistry (IHC) in 109 paired GC and para-cancerous normal tissue samples. The mRNA expression was detected in 36 pairs of tissue samples. IHC results and RNA-seq data extracted from The Cancer Genome Atlas (TCGA) were used to explore the clinical value of ERCC6 and ERCC8 expression in GC. We further conducted protein-protein interaction analysis, Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, gene set enrichment analysis, and gene-gene interaction analysis to explore the function and regulation networks of ERCC6 and ERCC8 in GC.

Results

Individual and joint ERCC6/ERCC8 expression were significantly higher in adjacent normal mucosa compared with GC tissues. ERCC6 mRNA expression showed no difference in GC and paired tissues, while ERCC8 mRNA was significantly decreased in GC tissues. Protein expression of ERCC6, ERCC8, double negative ERCC6-ERCC8 and double positive ERCC6-ERCC8 and overexpressed ERCC6 mRNA were related to better clinicopathologic parameters, while overexpressed ERCC8 mRNA suggested worse parameters. Univariate survival analysis indicated that the OS was longer when ERCC6 protein expression and ERCC8 mRNA expression increased, and double negative ERCC6-ERCC8 expression was associated with a short OS. Bioinformatics analyses showed ERCC6 and ERCC8 were associated with nucleotide excision repair (NER) pathway, and six and ten gene sets were figured out to be related with ERCC6 and ERCC8, respectively. KEGG pathway showed that ERCC6/ERCC8 related gene sets were mainly involved in the regulation of PI3K/AKT/mTOR pathway. Direct physical interactions were found between ERCC6 and ERCC8.

Conclusions

Individual and joint expressions of ERCC6/ERCC8 were associated with clinical features of GC. Protein expression of ERCC6, ERCC6-ERCC8, and mRNA expression of ERCC8 were related to prognosis of GC. ERCC6 and ERCC8 primarily function in the NER pathway, and may regulate GC progression through the regulation of PI3K/AKT/mTOR pathway.

Fiber burden and asbestos-related diseases: an umbrella review

Objective:

What are the levels of asbestos exposure that cause each type of health effect? The objective of this study was to review the available scientific evidence on exposure levels for asbestos and their relationship to health effects.

Method:

An umbrella review of English-language reviews and meta-analyses, from 1980 to March 2021 was conducted. We included reviews involving quantified asbestos exposures and health outcomes. The review has been adapted to the indications of the PRISMA declaration. Methodological quality of the selected studies was assessed using the AMSTAR instrument.

Results:

We retrieved 196 references. After applying the search strategy and quality analysis, 10 reviews were selected for in-depth analysis. For lung cancer, the highest risk was observed with exposure to amphiboles. Longer, thinner fibers had the greatest capacity to cause lung cancer, especially those > 10 μm in length. For mesothelioma, longer and thinner fibers were also more pathogenic; amphiboles ≥ 5 μm are especially associated with increased mesothelioma risk. No studies observed an increased risk for lung cancer or mesothelioma at asbestos exposure levels < 0.1 f/ml. No reviews provided information on exposure concentrations for pulmonary fibrosis. Currently, there is limited evidence in humans to establish the causal relationship between gastrointestinal cancer and asbestos exposure.

Conclusions:

Banning all asbestos exposure remains the best measure to preventing its negative health effects. The highest quality reviews and meta-analyses support that there is little risk of lung cancer or mesothelioma at daily exposure levels below 0.1 f/ml.

Polystyrene Nanoplastics as Carriers of Metals. Interactions of Polystyrene Nanoparticles with Silver Nanoparticles and Silver Nitrate, and Their Effects on Human Intestinal Caco-2 Cells

Environmental plastic wastes are continuously degraded to their micro and nanoforms. Since in the environment they coexist with other pollutants, it has been suggested that they could act as vectors transporting different toxic trace elements, such as metals. To confirm this, we have assessed the potential interactions between nanopolystyrene, as a model of nanoplastic debris, and silver compounds (silver nanoparticles and silver nitrate), as models of metal contaminant. Using TEM-EDX methodological approaches, we have been able to demonstrate metal sorption by nanopolystyrene. Furthermore, using Caco-2 cells and confocal microscopy, we have observed the co-localization of nanopolystyrene/nanosilver in different cellular compartments, including the cell nucleus. Although the internalization of these complexes showed no exacerbated cytotoxic effects, compared to the effects of each compound alone, the silver/nanopolystyrene complexes modulate the cell’s uptake of silver and slightly modify some harmful cellular effects of silver, such as the ability to induce genotoxic and oxidative DNA damage.

Implications of the germline variants of DNA damage response genes detected by cancer precision medicine for radiological risk communication and cancer therapy decisions

Large-scale cancer-associated gene testing is now being rapidly incorporated into clinical settings, and is leading to incidental identification of the germline variants present in cancer patients. Because many cancer susceptibility genes are related to DNA damage response and repair, the variants may reflect not only the susceptibility to cancer but also the genetically defined radiation sensitivity of the patients and their relatives. When the presence of a certain germline variant increases the risk for developing radiation toxicity or radiation-induced secondary cancers, it will greatly influence the clinical decision-making. In order to achieve optimal radiological risk communication and to select the best cancer management for a given patient based on information from gene testing, healthcare professionals including genetic counselors, risk communicators and clinicians need to increase their knowledge of the health effects of various genetic variants. While germline loss-of-function mutations in both of the alleles of the DNA damage response genes cause rare hereditary diseases characterized by extreme hypersensitivity to radiation, the health effects of the carriers who have germline variants in one allele of such genes would be a matter of debate, especially when the significance of the variants is currently unknown. In this review, we describe the clinical significance of the genetic variants of the important DNA damage response genes, including ATM and TP53, and discuss how we can apply current knowledge to the management of cancer patients and their relatives from a radiological point of view.

Epigenetic targeted therapy of stabilized BAP1 in ASXL1 gain-of-function mutated leukemia

Mutations of ASXL1, encoding a component of the BAP1 histone H2A deubiquitinase complex, occur in human myeloid neoplasms and are uniformly associated with poor prognosis. However, the precise molecular mechanisms through which ASXL1 mutations alter BAP1 activity and drive leukemogenesis remain unclear. Here we demonstrate that cancer-associated frameshift mutations in ASXL1, which were originally proposed to act as destabilizing loss-of-function mutations, in fact encode stable truncated gain-of-function proteins. Truncated ASXL1 increases BAP1 protein stability, enhances BAP1 recruitment to chromatin and promotes the expression of a pro-leukemic transcriptional signature. Through a biochemical screen, we identified BAP1 catalytic inhibitors that inhibit truncated-ASXL1-driven leukemic gene expression and impair tumor progression in vivo. This study represents a breakthrough in our understanding of the molecular mechanisms of ASXL1 mutations in leukemia pathogenesis and identifies small-molecular catalytic inhibitors of BAP1 as a potential targeted therapy for leukemia.

Genetics of Familial Non-Medullary Thyroid Carcinoma (FNMTC)

Non-medullary thyroid carcinoma (NMTC) is the most frequent endocrine tumor and originates from the follicular epithelial cells of the thyroid. Familial NMTC (FNMTC) has been defined in pedigrees where two or more first-degree relatives of the patient present the disease in absence of other predisposing environmental factors. Compared to sporadic cases, FNMTCs are often multifocal, recurring more frequently and showing an early age at onset with a worse outcome. FNMTC cases show a high degree of genetic heterogeneity, thus impairing the identification of the underlying molecular causes. Over the last two decades, many efforts in identifying the susceptibility genes in large pedigrees were carried out using linkage-based approaches and genome-wide association studies, leading to the identification of susceptibility loci and variants associated with NMTC risk. The introduction of next-generation sequencing technologies has greatly contributed to the elucidation of FNMTC predisposition, leading to the identification of novel candidate variants, shortening the time and cost of gene tests. In this review we report the most significant genes identified for the FNMTC predisposition. Integrating these new molecular findings in the clinical data of patients is fundamental for an early detection and the development of tailored therapies, in order to optimize patient management.

Down-regulation of RBP4 indicates a poor prognosis and correlates with immune cell infiltration in hepatocellular carcinoma

Recent research has indicated that metabolically related genes play crucial roles in the pathogenesis of hepatocellular carcinoma (HCC). We evaluated the associations between novel biomarkers and retinol-binding protein 4 (RBP4) for predicting clinical HCC outcomes, hub-related genes, pathway regulation, and immune cells infiltration. Bioinformatic analyses based on data from The Cancer Genome Atlas were performed using online analysis tools. RBP4 expression was low in HCC and was also down-regulated in pan-cancers compared with normal tissues. RBP4 expression was also significantly different based on age (41–60 years old versus 61–80 years old), and low RBP4 expression levels were associated with advanced tumor stages and grades. Higher RBP4 expression was associated with better overall survival time in HCC patients, and we identified a deletion-mutation rate of 1.4% in RBP4. We also identified ten co-expressed genes most related to RBP4 and explored the relationships between six hub genes (APOB, FGA, FGG, SERPINC1, APOA1, and F2) involved in RBP4 regulation. A pathway enrichment analysis for RBP4 indicated complement and coagulation cascades, metabolic pathways, antibiotic biosynthesis pathways, peroxisome proliferator-activated receptor signaling pathways, and pyruvate metabolism pathways. These results suggest that RBP4 may be a novel biomarker for HCC prognosis, and an indicator of low immune response to the disease.

Coronavirus 2019 Infectious Disease Epidemic: Where We Are, What Can Be Done and Hope For

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spreads mainly by means of aerosols (microdroplets) in enclosed environments, especially those in which temperature and humidity are regulated by means of air-conditioning. About 30% of individuals infected with SARS-CoV-2 develop coronavirus disease 2019 (COVID-19) disease. Among them, approximately 25% require hospitalization. In medicine, cases are identified as those who become ill. During this pandemic, cases have been identified as those with a positive SARS-CoV-2 polymerase chain reaction test, including approximately 70% who were asymptomatic-this has caused unnecessary anxiety. Individuals more than 65 years old, those affected by obesity, diabetes, asthma, or are immune-depressed owing to cancer and other conditions, are at a higher risk of hospitalization and of dying of COVID-19. Healthy individuals younger than 40 years very rarely die of COVID-19. Estimates of the COVID-19 mortality rate vary because the definition of COVID-19-related deaths varies. Belgium has the highest death rate at 154.9 per 100,000 persons, because it includes anyone who died with symptoms compatible with COVID-19, even those never tested for SARS-CoV-2. The United States includes all patients who died with a positive test, whether they died because of, or with, SARS-CoV-2. Countries that include only patients in which COVID-19 was the main cause of death, rather than a cofactor, have lower death rates. Numerous therapies are being developed, and rapid improvements are anticipated. Because of disinformation, only approximately 50% of the U.S. population plans to receive a COVID-19 vaccine. By sharing accurate information, physicians, health professionals, and scientists play a key role in addressing myths and anxiety, help public health officials enact measures to decrease infections, and provide the best care for those who become sick. In this article, we discuss these issues.

Helicobacter pylori induced gastric carcinogenesis - The best molecular model we have?

Gastric carcinogenesis can be described as a consequence of multilevel molecular alterations that is triggered by a cascade of events. Historically, diet and environmental factors have been identified to substantially contribute to carcinogenesis before the discovery of Helicobacter pylori (H. pylori). But H. pylori infection has revolutionized the understanding of gastric carcinogenesis. Although the model of H. pylori-driven carcinogenesis remains valid, there is a continuous effort to precisely delineate the molecular pathways involved and to understand the interplay with additional risk factors including recent relevant knowledge on the stomach microbiota. In this review, we provide an updated view on the models of gastric carcinogenesis. This includes historically appreciated H. pylori-induced models and expands these taking recent molecular data into consideration. Based on the data provided, we conclude that indeed H. pylori-carcinogenesis remains one of the best-established models at least for a subset of gastric cancers. Implementation of the recently identified molecular subtypes in novel genetic animal models is required to expand our knowledge on H. pylori-independent carcinogenesis.

DAZAP2 acts as specifier of the p53 response to DNA damage

The DNA damage-responsive tumor suppressors p53 and HIPK2 are well established regulators of cell fate decision-making and regulate the cellular sensitivity to DNA-damaging drugs. Here, we identify Deleted in Azoospermia-associated protein 2 (DAZAP2), a small adaptor protein, as a novel regulator of HIPK2 and specifier of the DNA damage-induced p53 response. Knock-down or genetic deletion of DAZAP2 strongly potentiates cancer cell chemosensitivity both in cells and in vivo using a mouse tumour xenograft model. In unstressed cells, DAZAP2 stimulates HIPK2 polyubiquitination and degradation through interplay with the ubiquitin ligase SIAH1. Upon DNA damage, HIPK2 site-specifically phosphorylates DAZAP2, which terminates its HIPK2-degrading function and triggers its re-localization to the cell nucleus. Interestingly, nuclear DAZAP2 interacts with p53 and specifies target gene expression through modulating a defined subset of p53 target genes. Furthermore, our results suggest that DAZAP2 co-occupies p53 response elements to specify target gene expression. Collectively, our findings propose DAZAP2 as novel regulator of the DNA damage-induced p53 response that controls cancer cell chemosensitivity.

Asbestos and Zeolites: from A to Z via a Common Ion

Asbestos and zeolites are silicate-based minerals, linked inextricably via paradoxical similarities and differences which have emanated from different geological epochs. Both have been employed in the service of humanity through millennia: asbestos, for its "inextinguishable" quality of being an insulator against heat and fire; zeolite, a "boiling stone" with its volcanic and marine sedimentary rock origins, for its propensity to adsorb water and remove metals and toxins. Serious adverse health effects observed in asbestos miners as long ago as the 1st Century AD did not halt the rising popularity of asbestos. As the miracle material of the 1900s, asbestos production and consumption exploded, culminating in its ubiquity in ships, vehicles, homes, commercial buildings, and over 3000 different industrial and household products. Through the 1940s and 1950s, epidemiological studies concluded that asbestos was a likely cause of asbestosis, lung cancer, and malignant mesothelioma, and it is now banned in many but far from all countries. The long latency between exposure to asbestos and the occurrence of cancer has obscured the deadly consequences of asbestos exposure for centuries. Even today, a considerable part of the world population is insufficiently aware of the dangers of asbestos, and millions of tons of this carcinogen continue to be mined and used worldwide. Zeolites, both natural and synthetic, are microporous aluminosilicate minerals commonly used in a myriad of processes, in the petrochemical industry, in domestic appliances and cleaning agents, as commercial adsorbents and exchangers for toxins and pollutants, and as catalysts. Zeolites are found in agriculture, veterinary science, and human health. More recently, new materials such as carbon nanotubes are being employed in materials requiring durability and thermal and electrical conductivity, yet nanotubes are now joining the ranks of more established particulates such as asbestos and silica, in causing human disease. In this review, we compare and contrast the similarities and differences of these two groups of silicate minerals and their waxing and waning use in the employ of humanity.

Alterations in BAP1 Are Associated with Cisplatin Resistance through Inhibition of Apoptosis in Malignant Pleural Mesothelioma

PURPOSE

The clinical standard treatment for patients with malignant pleural mesothelioma (MPM) includes a cisplatin-based chemotherapy, leading to reduction of tumor size in only a minority of patients. Predicting response to chemotherapy in patients with MPM by using a genetic marker would, therefore, enable patient stratification.

EXPERIMENTAL DESIGN

In this retrospective biomarker study, eligible patients had resectable MPM, measurable disease, and available primary MPM tissue. All patients underwent first-line treatment with cisplatin and pemetrexed, followed by surgery. Thorough molecular analysis was performed (whole-exome and targeted deep sequencing, and copy-number analyses), and also mechanistic in vitro data (viability assays, Western blots, and immunoprecipitation) using mesothelioma cell lines with and without siRNA-mediated BRCA1-associated protein 1 (BAP1) knockdown were provided.

RESULTS

In a training cohort of patients with MPM (n = 28), mutations or deletions of BAP1 each predicted resistance to chemotherapy in patients with primary MPM. The negative predictive value of BAP1 loss in patients with MPM was confirmed by amplicon sequencing and copy-number array technology in an independent test cohort (n = 39). Preliminary mechanistic studies using siRNA-based knockdown of BAP1 in MPM cell culture models along with immunoprecipitation assays confirmed chemoresistance in vitro, possibly through inhibition of apoptosis and transcriptional regulation of the BAP1/HCF1/E2F1 axis.

CONCLUSIONS

Alterations in BAP1 in MPM were a negative predictor for response to chemotherapy and could possibly be used as a companion biomarker for treatment decision.

Emerging multifaceted roles of BAP1 complexes in biological processes

Histone H2AK119 mono-ubiquitination (H2AK119Ub) is a relatively abundant histone modification, mainly catalyzed by the Polycomb Repressive Complex 1 (PRC1) to regulate Polycomb-mediated transcriptional repression of downstream target genes. Consequently, H2AK119Ub can also be dynamically reversed by the BAP1 complex, an evolutionarily conserved multiprotein complex that functions as a general transcriptional activator. In previous studies, it has been reported that the BAP1 complex consists of important biological roles in development, metabolism, and cancer. However, identifying the BAP1 complex's regulatory mechanisms remains to be elucidated due to its various complex forms and its ability to target non-histone substrates. In this review, we will summarize recent findings that have contributed to the diverse functional role of the BAP1 complex and further discuss the potential in targeting BAP1 for therapeutic use.

Surgery for malignant pleural mesothelioma after radiotherapy (SMART): final results from a single-centre, phase 2 trial

BACKGROUND

A novel approach for managing malignant pleural mesothelioma, surgery for mesothelioma after radiotherapy (SMART), consisting of a short accelerated course of high-dose, hemithoracic, intensity modulated radiotherapy (IMRT) followed by extrapleural pneumonectomy was developed. The aim of this study was to evaluate the clinical feasibility of the SMART protocol.

METHODS

In this single-centre, phase 2 trial, patients aged 18 years or older with an Eastern Cooperative Oncology Group performance status of 0-2, with histologically proven, resectable, cT1-3N0M0 disease who had previously untreated malignant pleural mesothelioma were eligible for inclusion. Patients received 25 Gy in five daily fractions over 1 week to the entire ipsilateral hemithorax with a concomitant 5 Gy boost to high risk areas followed by extrapleural pneumonectomy within 1 week. Adjuvant chemotherapy was offered to patients with ypN+ disease on final pathology. The primary endpoint was feasibility, which was defined as the number of patients with 30-day perioperative treatment-related death (grade 5 events) or morbidity (grade 3 or 4 events). A key secondary endpoint was cumulative incidence of distant recurrence. The final analysis was done on an intention-to-treat basis (including all eligible patients). This trial is registered with ClinicalTrials.gov, NCT00797719.

FINDINGS

Between Nov 1, 2008, and Oct 31, 2019, 102 patients were enrolled onto the trial and 96 eligible patients were treated with SMART on protocol and included in the analysis. Extrapleural pneumonectomy was done at a median of 5 days (range 2-12) after completing IMRT. 47 (49%) patients had 30-day perioperative grade 3-4 events and one (1%) patient died within 30 days perioperatively (grade 5 event; pneumonia). After a median follow-up of 46·8 months (IQR 13·4-61·2), the 5-year cumulative incidence of distant recurrence was 62 (63·3% [95% CI 52·3-74·4]). The most common first sites of recurrence were the contralateral chest (33 [46%] of 72 patients) and the peritoneal cavity (32 [44%]).

INTERPRETATION

Results from this study suggest that extrapleural pneumonectomy after radiotherapy can be done with good early and long-term results. However, minimising grade 4 events on the protocol is technically demanding and might affect survival beyond the post-operative period.

FUNDING

Princess Margaret Hospital Foundation Mesothelioma Research Fund.

Leveraging phenotypic variability to identify genetic interactions in human phenotypes

Although thousands of loci have been associated with human phenotypes, the role of gene-environment (GxE) interactions in determining individual risk of human diseases remains unclear. This is partly because of the severe erosion of statistical power resulting from the massive number of statistical tests required to detect such interactions. Here, we focus on improving the power of GxE tests by developing a statistical framework for assessing quantitative trait loci (QTLs) associated with the trait means and/or trait variances. When applying this framework to body mass index (BMI), we find that GxE discovery and replication rates are significantly higher when prioritizing genetic variants associated with the variance of the phenotype (vQTLs) compared to when assessing all genetic variants. Moreover, we find that vQTLs are enriched for associations with other non-BMI phenotypes having strong environmental influences, such as diabetes or ulcerative colitis. We show that GxE effects first identified in quantitative traits such as BMI can be used for GxE discovery in disease phenotypes such as diabetes. A clear conclusion is that strong GxE interactions mediate the genetic contribution to body weight and diabetes risk.

Heterozygous germline BLM mutations increase susceptibility to asbestos and mesothelioma

Rare biallelic BLM gene mutations cause Bloom syndrome. Whether BLM heterozygous germline mutations (BLM ^+/-) cause human cancer remains unclear. We sequenced the germline DNA of 155 mesothelioma patients (33 familial and 122 sporadic). We found 2 deleterious germline BLM ^+/- mutations within 2 of 33 families with multiple cases of mesothelioma, one from Turkey (c.569_570del; p.R191Kfs*4) and one from the United States (c.968A>G; p.K323R). Some of the relatives who inherited these mutations developed mesothelioma, while none with nonmutated BLM were affected. Furthermore, among 122 patients with sporadic mesothelioma treated at the US National Cancer Institute, 5 carried pathogenic germline BLM ^+/- mutations. Therefore, 7 of 155 apparently unrelated mesothelioma patients carried BLM ^+/- mutations, significantly higher (P = 6.7E-10) than the expected frequency in a general, unrelated population from the gnomAD database, and 2 of 7 carried the same missense pathogenic mutation c.968A>G (P = 0.0017 given a 0.00039 allele frequency). Experiments in primary mesothelial cells from Blm ^+/- mice and in primary human mesothelial cells in which we silenced BLM revealed that reduced BLM levels promote genomic instability while protecting from cell death and promoted TNF-α release. Blm ^+/- mice injected intraperitoneally with asbestos had higher levels of proinflammatory M1 macrophages and of TNF-α, IL-1β, IL-3, IL-10, and IL-12 in the peritoneal lavage, findings linked to asbestos carcinogenesis. Blm ^+/- mice exposed to asbestos had a significantly shorter survival and higher incidence of mesothelioma compared to controls. We propose that germline BLM ^+/- mutations increase the susceptibility to asbestos carcinogenesis, enhancing the risk of developing mesothelioma.

Integrative genomic analysis implicates ERCC6 and its interaction with ERCC8 in susceptibility to breast cancer

Up to 30% of all breast cancer cases may be inherited and up to 85% of those may be due to segregation of susceptibility genes with low and moderate risk [odds ratios (OR) ≤ 3] for (mostly peri- and post-menopausal) breast cancer. The majority of low/moderate-risk genes, particularly those with minor allele frequencies (MAF) of < 30%, have not been identified and/or validated due to limitations of conventional association testing approaches, which include the agnostic nature of Genome Wide Association Studies (GWAS). To overcome these limitations, we used a hypothesis-driven integrative genomics approach to test the association of breast cancer with candidate genes by analyzing multi-omics data. Our candidate-gene association analyses of GWAS datasets suggested an increased risk of breast cancer with ERCC6 (main effect: 1.29 ≤ OR ≤ 2.91, 0.005 ≤ p ≤ 0.04, 11.8 ≤ MAF ≤ 40.9%), and implicated its interaction with ERCC8 (joint effect: 3.03 ≤ OR ≤ 5.31, 0.01 ≤ pinteraction ≤ 0.03). We found significant upregulation of ERCC6 (p = 7.95 × 10-6) and ERCC8 (p = 4.67 × 10-6) in breast cancer and similar frequencies of ERCC6 (1.8%) and ERCC8 (0.3%) mutations in breast tumors to known breast cancer susceptibility genes such as BLM (1.9%) and LSP1 (0.3%). Our integrative genomics approach suggests that ERCC6 may be a previously unreported low- to moderate-risk breast cancer susceptibility gene, which may also interact with ERCC8.

Genetic Mutations and Variants in the Susceptibility of Familial Non-Medullary Thyroid Cancer

Thyroid cancer is the most frequent endocrine malignancy with the majority of cases derived from thyroid follicular cells and caused by sporadic mutations. However, when at least two or more first degree relatives present thyroid cancer, it is classified as familial non-medullary thyroid cancer (FNMTC) that may comprise 3-9% of all thyroid cancer. In this context, 5% of FNMTC are related to hereditary syndromes such as Cowden and Werner Syndromes, displaying specific genetic predisposition factors. On the other hand, the other 95% of cases are classified as non-syndromic FNMTC. Over the last 20 years, several candidate genes emerged in different studies of families worldwide. Nevertheless, the identification of a prevalent polymorphism or germinative mutation has not progressed in FNMTC. In this work, an overview of genetic alteration related to syndromic and non-syndromic FNMTC is presented.

Asbestos induces mesothelial cell transformation via HMGB1-driven autophagy

Asbestos causes malignant transformation of primary human mesothelial cells (HM), leading to mesothelioma. The mechanisms of asbestos carcinogenesis remain enigmatic, as exposure to asbestos induces HM death. However, some asbestos-exposed HM escape cell death, accumulate DNA damage, and may become transformed. We previously demonstrated that, upon asbestos exposure, HM and reactive macrophages releases the high mobility group box 1 (HMGB1) protein that becomes detectable in the tissues near asbestos deposits where HMGB1 triggers chronic inflammation. HMGB1 is also detectable in the sera of asbestos-exposed individuals and mice. Searching for additional biomarkers, we found higher levels of the autophagy marker ATG5 in sera from asbestos-exposed individuals compared to unexposed controls. As we investigated the mechanisms underlying this finding, we discovered that the release of HMGB1 upon asbestos exposure promoted autophagy, allowing a higher fraction of HM to survive asbestos exposure. HMGB1 silencing inhibited autophagy and increased asbestos-induced HM death, thereby decreasing asbestos-induced HM transformation. We demonstrate that autophagy was induced by the cytoplasmic and extracellular fractions of HMGB1 via the engagement of the RAGE receptor and Beclin 1 pathway, while nuclear HMGB1 did not participate in this process. We validated our findings in a novel unique mesothelial conditional HMGB1-knockout (HMGB1-cKO) mouse model. Compared to HMGB1 wild-type mice, mesothelial cells from HMGB1-cKO mice showed significantly reduced autophagy and increased cell death. Autophagy inhibitors chloroquine and desmethylclomipramine increased cell death and reduced asbestos-driven foci formation. In summary, HMGB1 released upon asbestos exposure induces autophagy, promoting HM survival and malignant transformation.