Eosinophils, but not neutrophils, exibit an efficient DNA repair machinary and high nucleolar activity

BACKGROUND AND OBJECTIVES: Traditionally eosinophils have been considered terminally differentiated cells that play a role in host protection against parasites. However, there is some evidence showing that eosinophils are, in fact, multifunctional leukocytes involved in inflammatory responses, as well as in tissue homeostasis. We characterized the transcriptome profile of human eosinophils, and, for the purpose of comparison, the transcriptome profile of neutrophils, monocytes and hematopoietic progenitor cells. Moreover, we studied the activation of selected cellular processes for which a significant differential expression was demonstrated. DESIGN AND METHODS: We profiled gene expression using Affymetrix GeneChips. DNA repair capacity was tested using the comet assay. Nucleoli and their activity were characterized by transmission electron microscopy analysis, silver staining of nucleolus regions (AgNOR) and RNA staining. RESULTS: Gene expression profiling showed that eosinophils appear hierarchically closer to monocytes than to neutrophils. Gene ontology mapping of differentially expressed genes revealed that eosinophils express categories very similar to those expressed by monocytes, related to DNA repair and nucleolar functions. Moreover, our data show that eosinophils and monocytes maintain the ability to repair both double and single strand DNA breaks, whereas neutrophils lack this capacity. Furthermore, eosinophils exhibit nucleolar activity, which is lacking in neutrophils, but resembles that in monocytes. INTERPRETATION AND CONCLUSIONS: The presence of large, active nucleoli in eosinophils, coupled to marked activity of DNA repair systems, suggests that eosinophils are not terminally differentiated cells. Indeed, their transcriptome profile and functional properties are more similar to those of non-terminally differentiated cells such as monocytes, rather than to neutrophils

Gene expression profiling of normal and malignant CD34-derived megakaryocytic cells

Abstract Gene expression profiles of bone marrow (BM) CD34-derived megakaryocytic cells (MKs) were compared in patients with essential thrombocythemia (ET) and healthy subjects using oligonucleotide microarray analysis to identify differentially expressed genes and disease-specific transcripts. We found that proapoptotic genes such as BAX, BNIP3, and BNIP3L were down-regulated in ET MKs together with genes that are components of the mitochondrial permeability transition pore complex, a system with a pivotal role in apoptosis. Conversely, antiapoptotic genes such as IGF1-R and CFLAR were up-regulated in the malignant cells, as was the SDF1 gene, which favors cell survival. On the basis of the array results, we characterized apoptosis of normal and ET MKs by time-course evaluation of annexin-V and sub-G1 peak DNA stainings of immature and mature MKs after culture in serum-free medium with an optimal thrombopoietin concentration, and annexin-V–positive MKs only, with decreasing thrombopoietin concentrations. ET MKs were more resistant to apoptosis than their normal counterparts. We conclude that imbalance between proliferation and apoptosis seems to be an important step in malignant ET megakaryocytopoiesis

Management of PALB2-associated breast cancer: A literature review and case report

Key Clinical Message Germline pathogenic variants (PV) of the PALB2 tumor suppressor gene are associated with an increased risk of breast, pancreatic, and ovarian cancer. In previous research, PALB2-associated breast cancer showed aggressive clinicopathological phenotypes, particularly triple-negative subtype, and higher mortality regardless of tumor stage, type of chemotherapy nor hormone receptor status. The identification of this germline alteration may have an impact on clinical management of breast cancer (BC) from the surgical approach to the systemic treatment choice. We herein report the case of a patient with a germline PV of PALB2, diagnosed with locally advanced PD-L1 positive triple-negative BC, who progressed after an immune checkpoint inhibitor (ICI)-containing regimen and then experienced a pathologic complete response after platinum-based chemotherapy. This case report hints a major role of the germline PALB2 alteration compared to the PD-L1 expression as cancer driver and gives us the opportunity to extensively review and discuss the available literature on the optimal management of PALB2-associated BC. Overall, our case report and review of the literature provide additional evidence that the germline analysis of PALB2 gene should be included in routine genetic testing for predictive purposes and to refine treatment algorithms

Hereditary pancreatic cancer: A retrospective single-center study of 5143 Italian families with history of BRCA-related malignancies

The identification of BRCA mutations plays a crucial role in the management of hereditary cancer prevention and treatment. Nonetheless, BRCA-testing in pancreatic cancer (PC) patients is not universally introduced in clinical practice. A retrospective analysis was conducted, firstly, to evaluate the rate of BRCA-positive families among those presenting a family history of PC besides breast and/or ovarian cancer. Secondly, the relationship between BRCA pathogenic variants and PC risk was evaluated. Finally, the characteristics of PC developed in BRCA families were described. Among 5143 family trees reporting breast and/or ovarian cancer cases, 392 showed a family history of PC. A total of 35 families (24.5% selected by the Modena Criteria and 21.3% by the NCCN Criteria) were positive to BRCA testing. Among the BRCA1 mutations, 36.8% were found within a region defined by c.3239\u2013c.3917, whilst 43.7% of BRCA2 mutations were located within c.7180\u2013c.8248. This study confirmed that an increase in the rate of positive tests in families with PC when associated to breast and/or ovarian tumors. Moreover, this analysis indicated two possible Pancreatic Cancer Cluster Regions that should be verified in future research. Finally, PC in families with breast and/or ovarian cancer history, particularly in BRCA families, were diagnosed at younger age and showed better one-year overall survival

STRATEGIES TO PREDICT TREATMENT RESPONSE AND SELECT THERAPIES IN METASTATIC BREAST CANCER PATIENTS USING A NEXT GENERATION SEQUENCING (NGS) MULTI-GENE PANEL

The standard of care for many patients with advanced breast cancer (BC )is gradually evolving from empirical treatment based on clinicalpathological characteristics to the use of targeted approaches based on the molecular profile of the tumor. In the last decade, an increasing number of molecularly targeted drugs have been developed for the treatment of metastatic BC. These drugs target specific molecular abnormalities that confer to cancer cells a survival advantage [1]. Interestingly, the ability to perform multigene testing for a range of molecular alterations may provide an opportunity to clarify the mechanisms of treatment response, to find the strategies to overcome treatment resistance and thus, to identify patients who are more likely to develop relapse and who may be candidates for matched targeted therapies [2-3]. The main aim of this study is to find prognostic and predictive molecular biomarkers for the management of metastatic BC patients in clinical practice. MATERIALS AND METHODS The amplicon-sequencing analyses took advantage of the Ion AmpliSeq™ technology (Thermo Fisher, Waltham, MA, USA). A custom panel was designed with the help of the Designer online tool (www.ampliseq.com), which was employed to generate optimized primers encompassing the coding DNA sequences (with 100bp of exon padding and the UTRs regions) of 25 genes in the Human Reference Genome (hg19); these genes were selected searching and screening scientific literature for treatments resistance in BC and are reported in Table 1. Primer pairs were divided into two pools to optimize multiplex PCR conditions and the coverage, that assessed to 89.02%. The customized Ion AmpliSeq panel was employed on samples from 7 primary BC samples and matched metastatic sites (3 skin, 3 lymph node and 1 lung metastases). They were all processed using the Ion AmpliSeq Library Kit 2.0, starting from 15 nanograms of FFPE extracted DNA/pool. Samples were barcoded with the Ion Express Kit to optimize matched patients pooling on the same 318 Chip v2 sequencing chip. The template-positive Ion Sphere Particles were sequenced on a Personal Genome Machine (Thermo Fisher, Waltham, MA, USA). RESULTS The mutation profiles of paired primary and secondary tumors of the seven patients enrolled in this study are presented in Table 2. Ten different genes (PTEN, PIK3CA, mTOR, ERBB2, ERBB3, MET, INPP4B, MAP2K1, CDK6, KRAS) in 6 different patients showed possible damaging variants as shown in Table 2. • Four patients (number 1, 3, 5 and 6) showed no additional or different mutations in secondary tumors if compared to primary samples. • In patient number 2, the metastatic site presented new mutations if compared to the primary tumor. • Finally in patient number 4 and 7 we did not detect in metastases some of the mutations found in the primary tumor. DISCUSSION In 5 patients (71,4%) the mutational status of primary tumor could explain treatment resistance and thus predict relapse, in one patient the mutational status of the new subclones could be relevant for guiding differently the subsequent treatment choices. In 2 patients (28,5%) we were not able to detect in metastases some of the mutations found in the primary tumor. This could be explained by considering the clonal evolution of metastases. These preliminary data suggest that the multi-gene panel analysis of primary and secondary tumors may help clinicians: • in discriminating BC patients HR+ and/or HER2+ with mutations predicting an increased risk of adjuvant treatment resistance and thus relapse • in guiding treatment selection strategies in the metastatic setting. The study is still open and we are currently recruiting other patients.The main aim of this study is to find prognostic and predictive molecular biomarkers for the management of metastatic BC patients in clinical practice. The preliminary data suggest that the multi-gene panel analysis of primary and secondary tumors may help clinicians: • in discriminating BC patients HR+ and/or HER2+ with mutations predicting an increased risk of adjuvant treatment resistance and thus relapse • in guiding treatment selection strategies in the metastatic setting. The study is still open and we are currently recruiting other patients

STRATEGIES TO PREDICT TREATMENT RESPONSE AND SELECT THERAPIES IN METASTATIC BREAST CANCER PATIENTS USING A NEXT GENERATION SEQUENCING MULTI-GENE PANEL

The standard of care for many patients with advanced breast cancer (BC )is gradually evolving from empirical treatment based on clinicalpathological characteristics to the use of targeted approaches based on the molecular profile of the tumor. In the last decade, an increasing number of molecularly targeted drugs have been developed for the treatment of metastatic BC. These drugs target specific molecular abnormalities that confer to cancer cells a survival advantage. Interestingly, the ability to perform multigene testing for a range of molecular alterations may provide an opportunity to clarify the mechanisms of treatment response, to find the strategies to overcome treatment resistance and thus, to identify patients who are more likely to develop relapse and who may be candidates for matched targeted therapies. The main aim of this study is to find prognostic and predictive molecular biomarkers for the management of metastatic BC patients in clinical practice

Targeted cancer exome sequencing reveals recurrent mutations in myeloproliferative neoplasms

With the intent of dissecting the molecular complexity of Philadelphia-negative myeloproliferative neoplasms (MPN), we designed a target enrichment panel to explore, using next-generation sequencing (NGS), the mutational status of an extensive list of 2,000 cancer-associated genes and microRNAs. The genomic DNA of granulocytes and in-vitro-expanded CD3+ T-lymphocytes, as a germline control, was target-enriched and sequenced in a learning cohort of 20 MPN patients using Roche 454 technology. We identified 141 genuine somatic mutations, most of which were not previously described. To test the frequency of the identified variants, a larger validation cohort of 189 MPN patients was additionally screened for these mutations using Ion Torrent AmpliSeq NGS. Excluding the genes already described in MPN, for 8 genes (SCRIB, MIR662, BARD1, TCF12, FAT4, DAP3, POLG, and NRAS), we demonstrated a mutation frequency between 3 and 8%. We also found that mutations at codon 12 of NRAS (NRASG12V and NRASG12D) were significantly associated, for primary myelofibrosis (PMF), with highest DIPSS-plus score categories. This association was then confirmed in 66 additional PMF patients composing a final dataset of 168 PMF showing an NRAS mutation frequency of 4.7%, which was associated with a worse outcome, as defined by the DIPSS plus score

The early expansion of anergic NKG2Apos/CD56dim/CD16neg natural killer cells represents a therapeutic target in haploidentical haematopoietic stem cell transplantation

Natural Killer cells are the first lymphocyte population to reconstitute early after non myelo-ablative and T cell-replete haploidentical hematopoietic stem cell transplantation with post-transplant infusion of cyclophosphamide. The present study characterizes the transient and predominant expansion starting from the 2nd week after haploidentical hematopoietic stem cell transplantation of a donor-derived unconventional subset of NKp46neg-low/CD56dim/CD16neg natural killer cells expressing remarkable high levels of CD94/NKG2A. Both transcription and phenotypic profiles indicated that unconventional NKp46neg-low/CD56dim/CD16neg natural killer cells are a distinct natural killer cell subpopulation with features of late stage differentiation, yet retaining proliferative capability and functional plasticity to generate conventional NKp46pos/CD56bright/CD16pos natural killer cells in response to interleukin-15 plus interleukin-18. While present at low frequency in healthy donors, unconventional NKp46neg-low/CD56dim/CD16neg natural killer cells are greatly expanded in the following 7 weeks after haploidentical hematopoietic stem cell transplantation and express high levels of the activating receptors NKGD and NKp30 as well as of the lytic granules Granzyme-B and Perforin. Nonetheless, NKp46neg-low/CD56dim/CD16neg natural killer cells displayed a markedly defective cytotoxicity that could be reversed by blocking the inhibitory receptor CD94/NKG2A. These data open new important perspectives to better understand the ontogenesis/homeostasis of human natural killer cells and to develop a novel immune-therapeutic approach that targets the inhibitory NKG2A check point, thus unleashing natural killer cell alloreactivity early after haploidentical hematopoietic stem cell transplantation

AMPLICON-BASED NGS: AN EFFECTIVE APPROACH FOR THE MOLECULAR DIAGNOSIS OF EPIDERMOLYSIS BULLOSA

Background: Epidermolysis Bullosa (EB) is caused by mutations in genes that encode proteins belonging to the epidermal-dermal junction assembly. Due to the extreme clinical/genetic heterogeneity of the disease, the current methods available for diagnosing EB involve immunohistochemistry of bioptic samples and transmission electron microscopy followed by single candidate gene Sanger Sequencing (SS), which are labour intensive and expensive clinical pathways. Objectives: According to the recently published recommendations for the EB diagnosis and treatment, the assessment of the mutational landscape is now a fundamental step for developing a comprehensive diagnostic path. Next-Generation Sequencing (NGS) via the parallel ultra-deep sequencing of many genes represents a proper method for reducing the processing time and costs of EB diagnostics. Methods: We developed an EB disease-comprehensive AmpliSeq panel to accomplish the NGS on the Ion Torrent PGM platform. The panel was performed on ten patients with known genetic diagnoses and was then employed in eight family trios with unknown molecular footprints. Results: The panel was successful in finding the causative mutations in all ten of the patients with known mutations, fully confirming the SS data and providing proof of concept of the sensitivity, specificity, and accuracy of this procedure. In addition to being consistent with the clinical diagnosis, it was also effective in the trios, identifying all of the variants, including ones that the SS missed or de novo mutations. Conclusions: The NGS and AmpliSeq were shown to be an effective approach for the diagnosis of EB, resulting in a costand time-effective 72-hour procedure

Workload measurement for molecular genetics laboratory: A survey study

Genetic testing availability in the health care system is rapidly increasing, along with the diffusion of next-generation sequencing (NGS) into diagnostics. These issues make imperative the knowledge-drive optimization of testing in the clinical setting. Time estimations of wet laboratory procedure in Italian molecular laboratories offering genetic diagnosis were evaluated to provide data suitable to adjust efficiency and optimize health policies and costs. A survey was undertaken by the Italian Society of Human Genetics (SIGU). Forty-two laboratories participated. For most molecular techniques, the most time-consuming steps are those requiring an intensive manual intervention or in which the human bias can affect the global process time-performances. For NGS, for which the study surveyed also the interpretation time, the latter represented the step that requiring longer times. We report the first survey describing the hands-on times requested for different molecular diagnostics procedures, including NGS. The analysis of this survey suggests the need of some improvements to optimize some analytical processes, such as the implementation of laboratory information management systems to minimize manual procedures in pre-analytical steps which may affect accuracy that represents the major challenge to be faced in the future setting of molecular genetics laboratory