Small supernumerary marker chromosomes derived from human chromosome 11

Introduction: With only 39 reported cases in the literature, carriers of a small supernumerary marker chromosome (sSMC) derived from chromosome 11 represent an extremely rare cytogenomic condition. Methods: Herein, we present a review of reported sSMC(11), add 18 previously unpublished cases, and closely review eight cases classified as 'centromere-near partial trisomy 11' and a further four suited cases from DECIPHER. Results and discussion: Based on these data, we deduced the borders of the pericentric regions associated with clinical symptoms into a range of 2.63 and 0.96 Mb for chromosome 11 short (p) and long (q) arms, respectively. In addition, the minimal pericentric region of chromosome 11 without triplo-sensitive genes was narrowed to positions 47.68 and 60.52 Mb (GRCh37). Furthermore, there are apparent differences in the presentation of signs and symptoms in carriers of larger sSMCs derived from chromosome 11 when the partial trisomy is derived from different chromosome arms. However, the number of informative sSMC(11) cases remains low, with overlapping presentation between p- and q-arm-imbalances. In addition, uniparental disomy (UPD) of 'normal' chromosome 11 needs to be considered in the evaluation of sSMC(11) carriers, as imprinting may be an influencing factor, although no such cases have been reported. Comprehensively, prenatal sSMC(11) cases remain a diagnostic and prognostic challenge.

Recommendations for reporting results of diagnostic genomic testing

Results of clinical genomic testing must be reported in a clear, concise format to ensure they are understandable and interpretable. It is important laboratories are aware of the information which is essential to make sure the results are not open to misinterpretation. As genomic testing has continued to evolve over the past decade, the European Society of Human Genetics (ESHG) recommendations for reporting results of diagnostic genetic testing (biochemical, cytogenetic and molecular genetic) published in 2014 have been reviewed and updated to provide the genomic community with guidance on reporting unambiguous results.

Somatic homozygous loss of SH2B3, and a non-Robertsonian translocation t(15;21)(q25.3;q22.1) with NTRK3 rearrangement, in an adolescent with progenitor B-cell acute lymphoblastic leukemia with the iAMP21

Intrachromosomal amplification of chromosome 21 (iAMP21) occurs in ∼2% of B-cell acute lymphoblastic leukemia (ALL) and is considered to confer a poor prognosis. The relapse risk is associated with therapy intensity, suggesting that other somatic mutations may influence iAMP21-ALL prognosis. This abnormality is characterized by multiple copies of the RUNX1 gene in chromosome 21 and appears to arise through multiple breakage-fusion bridge cycles and chromothripsis. Rob(15;21) or a ring chromosome 21 have been associated with an increased risk for iAMP21-ALL, suggesting that constitutional genetic abnormalities may also drive leukemogenesis. Here we describe homozygous deletion of the SH2B3 gene, chromothripsis of chromosome 21, and a non-Robertsonian somatic t(15;21)(q25.3;q22.1) with NTRK3 gene rearrangement in an adolescent with iAMP21-B-ALL. Molecular cytogenetic studies detected iAMP21 with aCGH analysis revealing further genomic imbalances. The RT-qPCR analysis detected elevated expression levels of RUNX1 (68-fold) and reduced expression of CDK6 (0.057-fold). Studies with constitutive cells collected from mouth swabs showed that SH2B3 biallelic deletion was a somatic alteration occurring during clonal evolution. The identification of novel secondary genetic changes was valuable to discuss sporadic iAMP21 leukemogenic mechanisms. For the first time, we show a t(15;21)(q25.3;q22.1) with NTRK3 rearrangement in an adolescent with iAMP21-ALL.

A new childhood ALL case with an extremely complex karyotype and acute spontaneous tumor lysis syndrome

BACKGROUND

B cell precursor acute lymphoblastic leukemia (B-ALL) is the most common malignancy of childhood, with, after corresponding treatment, an overall complete remission rate of 90%. Approximately 75% of B-ALL cases harbor recurrent abnormalities, including so-called complex karyotypes (CK). Tumor lysis syndrome (TLS) is a metabolic abnormality which may arise during cancer therapy and also, extremely rarely, as spontaneous TLS before initiation of chemotherapy in patients with ALL.

CASE PRESENTATION

Here we report a 9-year-old male, diagnosed with a de novo pre-B-ALL according to the WHO classification. Cytogenetic, molecular cytogenetic approaches and array comparative genomic hybridization analyses revealed a unique CK involving five chromosomes. It included four yet unreported chromosomal aberrations: a der(11)t(7;11)(p22.1;q24.2), a der(18)t(7;18)(q21.3;p11.22), del(11)(q24.2q25) and dup(18)(q11.1q23). Unfortunately, the patient died 3 months after the initial diagnosis.

CONCLUSIONS

To the best of our knowledge, a comparable childhood ALL case was not previously reported. Thus, the combination of the here seen chromosomal aberrations in childhood primary ALL seems to indicate for an extremely adverse prognosis.

Probability distribution of copy number alterations along the genome: an algorithm to distinguish different tumour profiles

Copy number alterations (CNAs) comprise deletions or amplifications of fragments of genomic material that are particularly common in cancer and play a major contribution in its development and progression. High resolution microarray-based genome-wide technologies have been widely used to detect CNAs, generating complex datasets that require further steps to allow for the determination of meaningful results. In this work, we propose a methodology to determine common regions of CNAs from these datasets, that in turn are used to infer the probability distribution of disease profiles in the population. This methodology was validated using simulated data and assessed using real data from Head and Neck Squamous Cell Carcinoma and Lung Adenocarcinoma, from the TCGA platform. Probability distribution profiles were produced allowing for the distinction between different phenotypic groups established within that cohort. This method may be used to distinguish between groups in the diseased population, within well-established degrees of confidence. The application of such methods may be of greater value in the clinical context both as a diagnostic or prognostic tool and, even as a useful way for helping to establish the most adequate treatment and care plans.

An acquired stable variant of a dicentric dic(9;20) and complex karyotype in a Syrian childhood B-acute lymphoblastic leukemia case

BACKGROUND

About 25 years ago, the acquired chromosome abnormality dicentric dic(9;20)(p11 ~ 13;q11) was seen described as a non-random aberration in B-cell precursor acute lymphoblastic leukemia (BCP-ALL). Yet, about 200 cases were reported. However, dicentric dic(9;20) is a subtle abnormality which easily may be mixed up with monosomy 20 and/or del(9p). The dicentric dic(9;20) can be found as a sole chromosomal abnormality or can be masked within complex rearrangements; also, a dicentric dic(9;20) is often associated with mono- or biallelic loss of CDKN2A gene.

CASE PRESENTATION

Here we report a case of 16-year-old male diagnosed with a de novo pre-B-ALL. Molecular approaches (array-based multicolor banding (aMCB) and array comparative genomic hybridization (aCGH)) were applied, and a unique complex karyotype involving six chromosomes was identified. It included three previously unreported chromosomal aberrations: dicentric dic(9;20;X), deletion del(7)(p22.2p15.2) and dicentric dic(7;13). The dicentric dic(9;20;X) also led to monoallelic loss of tumor suppressor gene CDKN2A. After successful chemotherapeutic treatment the patient experienced a relapse with a secondary ALL without complex karyotype but a deletion del(19)(p13). Unfortunately, the patient died after 17 months of the initial diagnosis.

CONCLUSIONS

To the best of our knowledge, a comparable childhood ALL associated with such complex karyotype and deletion del(19)(p13) in secondary ALL was not previously reported. Thus, the complex karyotype with dicentrc dic(9;20;X) seems to indicate for a poor prognosis.

Complex karyotype with cryptic FUS gene rearrangement and deletion of NR3C1 and VPREB1 genes in childhood B-cell acute lymphoblastic leukemia: A case report

B-cell acute lymphoblastic leukemia (B-ALL) is a hematopoietic malignancy characterized by overproduction of immature B-lymphoblasts. B-ALL is the most common pediatric tumor and remains the leading cause of mortality in children and adolescents. Molecular and cytogenetic analyses of B-ALL revealed recurrent genetic and structural genomic alterations which are routinely applied for diagnosis, prognosis and choice of treatment regimen. The present case report describes a 4-year-old female diagnosed with B-ALL. GTG-banding at low resolution revealed an abnormal clone with 46,XX,?t(X;19)(q13;q13.3),der(9) besides normal cells. Molecular cytogenetics demonstrated a balanced translocation between chromosomes 16 and 19, and an unbalanced translocation involving chromosomes 5 and 9. A locus-specific probe additionally identified that the FUS gene in 16p11.2 was split and its 5' region was translocated to subband 19q13.33, whereas the 3' region of the FUS gene remained on the derivative chromosome 16. Overall, this complex karyotype included four different chromosomes and five break events. Further analyses, including array-comparative genomic hybridization, additionally revealed biallelic deletion of the tumor suppressor genes CDKN2A/B, and deletion of the NR3C1 and VPREB1 genes. The patient passed away under treatment due to sepsis.

Regarding the rights and duties of Clinical Laboratory Geneticists in genetic healthcare systems; results of a survey in over 50 countries

Specialists of human genetic diagnostics can be divided into four groups: Medical Geneticists (MDG), Genetic Nurses and/or Counsellors (GN/GC), Clinical Laboratory Geneticists (CLG) and Laboratory Genetics Technicians (LGT). While the first two groups are in direct patient contact, the work of the latter two, of equal importance for patient care, are often hidden as they work behind the scenes. Herein the first study on the rights and duties of CLGs is presented. We present the results of a survey performed in 35 European and 18 non-European countries with 100 participating specialists. A national CLG title is available in 60% of European countries, and in 77% of the surveyed European countries a CLG can be the main responsible head of the laboratory performing human genetic tests. However, in only 20% of European countries is a lab-report valid with only a CLGs' signature - even though the report is almost always formulated by the CLG, and an interpretation of the obtained results in a clinical context by the CLG is expected in nearly 90% of European countries. Interestingly, CLGs see patients in 30% of European countries, and are also regularly involved in student education. Overall, the CLG profession includes numerous duties, which are quite similar in all regions of the world. Strikingly, the CLG's rights and responsibilities of leading a lab, or signing a report are regulated differently according to country specific regulations. Overall, the CLG is a well-recognized profession worldwide and often working within a multidisciplinary team of human genetic diagnostics professionals.

A New Complex Karyotype Involving a KMT2A-r Variant Three-Way Translocation in a Rare Clinical Presentation of a Pediatric Patient with Acute Myeloid Leukemia

Patients with childhood acute myeloid leukemia (AML) with complex karyotypes (CKs) have a dismal outcome. However, for patients with a KMT2A rearrangement (KMT2A-r), the prognosis appears to depend on the fusion partner gene rather than the karyotype structure. Thus, a precise characterization of KMT2A-r and the fusion partner genes, especially in CKs, is of interest for managing AML. We describe the clinical and molecular features of a child who presented with a large abdominal mass, AML, and a new CK, involving chromosomes 11, 16, and 19 leading to a KMT2A-MLLT1 fusion and 2 extra copies of the ELL gene, thus resulting in the concurrent overexpression of MLLT1 and ELL. Molecular cytogenetic studies defined the karyotype as 47,XY,der(11)t(11;16)(q23.3;p11.2),der(16)t(16;19)(p11.2;p13.3),der(19)t(11;19)(q23.3;p13.3),+der(19)t(16;19)(16pter→p11.2::19p13.3→19q11::19p11→19p13.3::16p11.2→16pter). Array CGH revealed a gain of 30.5 Mb in the 16p13.3p11.2 region and a gain of 18.1 Mb in the 19p13.3p12 region. LDI-PCR demonstrated the KMT2A-MLLT1 fusion. Reverse sequence analysis showed that the MLLT1 gene was fused to the 16p11.2 region. RT-qPCR quantification revealed that ELL and MLLT1 were overexpressed (4- and 10-fold, respectively). In summary, this is a pediatric case of AML presenting a novel complex t(11;16;19) variant with overexpression of ELL and MLLT1.

Urine Nuclear Magnetic Resonance (NMR) Metabolomics in Age-Related Macular Degeneration

Biofluid biomarkers of age-related macular degeneration (AMD) are still lacking, and their identification is challenging. Metabolomics is well-suited to address this need, and urine is a valuable accessible biofluid. This study aimed to characterize the urinary metabolomic signatures of patients with different stages of AMD and a control group (>50 years). It was a prospective, cross-sectional study, where subjects from two cohorts were included: 305 from Coimbra, Portugal (AMD patients n = 252; controls n = 53) and 194 from Boston, United States (AMD patients n = 147; controls n = 47). For all participants, we obtained color fundus photographs (for AMD staging) and fasting urine samples, which were analyzed using 1H nuclear magnetic resonance (NMR) spectroscopy. Our results revealed that in both cohorts, urinary metabolomic profiles differed mostly between controls and late AMD patients, but important differences were also found between controls and subjects with early AMD. Analysis of the metabolites responsible for these separations revealed that, even though distinct features were observed for each cohort, AMD was in general associated with depletion of excreted citrate and selected amino acids at some stage of the disease, suggesting enhanced energy requirements. In conclusion, NMR metabolomics enabled the identification of urinary signals of AMD and its severity stages, which might represent potential metabolomic biomarkers of the disease.

Chromosomal breakpoints in a cohort of head and neck squamous cell carcinoma patients

Head and neck squamous cell carcinoma (HNSCC) presents complex chromosomal rearrangements, however, the molecular mechanisms behind HNSCC development remain elusive. The identification of the recurrent chromosomal breakpoints could help to understand these mechanisms. Array-CGH was performed in HNSCC patients and the chromosomal breakpoints involved in gene amplification/loss were analyzed. Frequent breakpoints were clustered in chromosomes 12p, 8p, 3q, 14q, 6p, 4q, Xq and 8q. Chromosomes 6, 14, 3, 8 and X exhibited higher susceptibility to have breaks than other chromosomes. We observed that low copy repeat DNA sequences are localized at or flanking breakpoint sites, ranging from 0 to 200 bp. LINES, SINES and Simple Repeats were the most frequent repeat elements identified in these regions. We conclude that in our cohort specific peri-centromeric and telomeric regions were frequently involved in breakpoints, being the presence of low copy repeats elements one of the explanations for the common rearrangement events observed.

Cytogenetic, genomic, and epigenetic characterization of the HSC-3 tongue cell line with lymph node metastasis

Oral carcinoma develops from squamous epithelial cells by the acquisition of multiple (epi) genetic alterations that target different genes and molecular pathways. Herein, we performed a comprehensive genomic and epigenetic characterization of the HSC-3 cell line through karyotyping, multicolor fluorescence in situ hybridization, array comparative genomic hybridization, and methylation-specific multiplex ligation-dependent probe amplification. HSC-3 turned out to be a near-triploid cell line with a modal number of 61 chromosomes. Banding and molecular cytogenetic analyses revealed that nonrandom gains of chromosomal segments occurred more frequently than losses. Overall, gains of chromosome 1, 3q, 5p, 7p, 8q, 9q, 10, 11p, 11q13, 12, 13, 14, 17, 18p, 20, Yp, and Xq were observed. The largest region affected by copy number loss was observed at chromosome 18q. Several of the observed genomic imbalances and their mapped genes were already associated with oral carcinoma and/or adverse prognosis, invasion, and metastasis in cancer. The most common rearrangements observed were translocations in the centromeric/near-centromeric regions. RARB, ESR1, and CADM1 genes were methylated and showed copy number losses, whereas TP73 and GATA5 presented with methylation and copy number gains. Thus, the current study presents a comprehensive characterization of the HSC-3 cell line; the use of this cell line may contribute to enriching the resources available for oral cancer research, especially for the testing of therapeutic agents.

Molecular approaches identify a cryptic MECOM rearrangement in a child with a rapidly progressive myeloid neoplasm

Myeloid neoplasms are a heterogeneous group of hematologic disorders with divergent patterns of cell differentiation and proliferation, as well as divergent clinical courses. Rare recurrent genetic abnormalities related to this group of cancers are associated with poor outcomes. One such abnormality is the MECOM gene rearrangement that typically occurs in cases with chromosome 7 abnormalities. MECOM encodes a transcription factor that plays an essential role in cell proliferation and maintenance and also in epigenetic regulation. Aberrant expression of this gene is associated with reduced survival. Hence, its detailed characterization provides biological and clinical information relevant to the management of pediatric myeloid neoplasms. In this work, we describe a rare karyotype harboring three copies of MECOM with overexpression of the gene in a child with a very aggressive myeloid neoplasm. Cytogenetic studies defined the karyotype as 46,XX,der(7)t(3;7)(q26.2;q21.2). Array comparative genomic hybridization (aCGH) revealed a gain of 26.04 Mb in the 3q26.2-3qter region and a loss of 66.6 Mb in the 7q21.2-7qter region. RT-qPCR analysis detected elevated expression of the MECOM and CDK6 genes (458.5-fold and 35.2-fold, respectively). Overall, we show the importance of performing detailed molecular cytogenetic analysis of MECOM to enable appropriate management of high-risk pediatric myeloid neoplasms.

Effects of resistance exercise on endothelial progenitor cell mobilization in women

This study aimed to determine the effect of a single bout of resistance exercise at different intensities on the mobilization of circulating EPCs over 24 hours in women. In addition, the angiogenic factors stromal cell-derived factor 1 (SDF-1α), vascular endothelial growth factor (VEGF), hypoxia-inducible factor 1-alpha (HIF-1α) and erythropoietin (EPO) were measured as potential mechanisms for exercise-induced EPCs mobilization. Thirty-eight women performed a resistance exercise session at an intensity of 60% (n = 13), 70% (n = 12) or 80% (n = 13) of one repetition maximum. Each session was comprised of three sets of 12 repetitions of four exercises: bench press, dumbbell curl, dumbbell squat, and standing dumbbell upright row. Blood was sampled at baseline and immediately, 6 hours, and 24 hours post-exercise. Circulating EPC and levels of VEGF, HIF-1α and EPO were significantly higher after exercise (P < 0.05). The change in EPCs from baseline was greatest in the 80% group (P < 0.05), reaching the highest at 6 hours post-exercise. The change in EPCs from baseline to 6 hours post-exercise was correlated with the change in VEGF (r = 0.492, P = 0.002) and HIF-1α (r = 0.388, P = 0.016). In general, a dose-response relationship was observed, with the highest exercise intensities promoting the highest increases in EPCs and angiogenic factors.

Genomic and epigenetic characterization for the comparison of synchronous bilateral tongue squamous cell carcinomas-A case report

The tongue is the most common and aggressive site for tumors in the oral cavity. These tumors are usually located in the lateral border of the tongue and are often related to the use of tobacco and alcohol. Clinical management of these tumors is predominantly based on anatomic location and TNM classification. The identification of molecular signatures with ability to explain the different outcomes observed in these patients is of paramount importance to guide and help their management.

CASE PRESENTATION

we herein describe an 88-year-old woman diagnosed with synchronous bilateral tongue carcinoma. This woman did not present the traditional risk factors related to oral cancer-alcohol, tobacco, or presence of human papiloma virus (HPV). Both tumors were classified by a pathologist as pT2. This patient was submitted to surgery, 6 months later was diagnosed with cervical metastasis and in the following 2 months died. Copy number alterations and methylation status of these 2 simultaneous tumors were analyzed using array comparative genomic hybridization, multiplex ligation-dependent probe amplification, and methylation specific multiplex ligation-dependent probe amplification. In conclusion, in both tumors we identified several molecular traits usually found among oral cavity tumors and some of those have been associated with clinical outcome, reinforcing their importance to accurately establish biomarkers with clinical applicability. Specific genomic and epigenetic signatures for each of these 2 tumors were also observed allowing their molecular discrimination. The tumor of the right side of the tongue exhibited more copy number gains than the tumor of the left side. In the left side tumor less and smaller copy number alterations and more methylated genes were observed, which could be indicative of an early phase of tumor development. This case shows the molecular heterogeneity of oral cavity tumors even in the same patient and anatomic site, which could be the key to explain the different outcomes of oral tumor patients.

Genomic profile of oral squamous cell carcinomas with an adjacent leukoplakia or with an erythroleukoplakia that evolved after the treatment of primary tumor: A report of two cases

Oral leukoplakia and erythroleukoplakia are common oral potentially malignant disorders diagnosed in the oral cavity. The specific outcome of these lesions remains to be elucidated, as their malignant transformation rate exhibits great variation. The ability to predict which of those potentially malignant lesions are likely to progress to cancer would be vital to guide their future clinical management. The present study reported two patients with tongue squamous cell carcinoma: Case study 1 was diagnosed with a simultaneous leukoplakia and case study 2 developed an erythroleukoplakia following the primary tumor treatment. Whole genome copy number alterations were analyzed using array comparative genomic hybridization. The present study determined more genomic imbalances in the tissues from leukoplakia and erythroleukoplakia compared with their respective tumors. The present study also identified in tumor and potentially malignant lesions common alterations of chromosomal regions and genes, including FBXL5, UGT2B15, UGT2B28, KANSL1, GSTT1 and DUSP22, being some of these typical aberrations described in oral cancer and others are linked to chemoradioresistance. Several putative genes associated with hallmarks of malignancy that may have an important role in predicting the progression of leukoplakia and erythroleukoplakia to squamous cell carcinoma, namely gains in BNIPL, MCL1, STAG2, CSPP1 and ZNRF3 genes were also identified.

Abstract 1915: Deconstructing cancer stem cells: IL-6, G-CSF and Activin-A as mediators of stroma-orchestrated epithelial cells’ dedifferentiation

Intercellular communication in cancer is a deceiving and extremely efficient process through which the corporal machinery is hijacked by a panoply of cellular and molecular strategies turning the entire human body into an evolutionary arena. The extensive crosstalk mediated by cytokines and chemokines overcome the inefficiency of the invasion-metastasis cascade, thus allowing the development of the often-fatal metastatic disease. Cancer stem cells (CSCs) have recently been implicated in major steps of the tumorigenic process, namely in tumor initiation, metastasis formation and tumor relapse following therapy. Yet, despite their relevance, the exact mechanisms underlying their formation are still unclear. After observing that the malignant human bronchial epithelial RenG2 cells dedifferentiated following culture in the subcutaneous mouse lumbar region, co-cultures of surgically isolated mice lumbar stromal cells with RenG2 cells were established and the conditioned media studied by multiplex and ELISA. Consequently, Interleukin-6 (IL-6), Granulocyte colony-stimulating factor (G-CSF) and Activin-A were identified as the paracrine mediators of the intercellular communication process. Aiming to ascertain the individual role of each cytokine in the dedifferentiation process, as well as to access the involvement of exosomes as transport vehicle, the same co-cultures were reproduced in the presence of specific cytokine-communication blockers, either individually or in combinations of up to three blockers, and exosome-mediated communication inhibitors. Finally, exosomes were also collected from control co-cultures and their cargo screened for the target cytokines. ELISA showed that the three cytokines were present inside fibroblasts-secreted exosomes. Moreover, whenever exosomes’ release was blocked, dedifferentiation was abrogated, further proving the role of the aforementioned cytokines and of exosomes in the dedifferentiation process. Additionally, the cytokine-blocking experiments revealed that only IL-6 and Activin-A were endowed with the potential to orchestrate dedifferentiation, as when at least one of these cytokines was present a stem cell population developed inside RenG2 cells. Finally, G-CSF appeared to be decisive in maintaining the undifferentiated phenotype, as a larger pool of CSCs was attained whenever this cytokine and either IL-6 or Activin-A were present. Altogether the attained results implicated IL-6 and Activin-A in the formation of CSCs by dedifferentiation, and G-CSF as a potent keeper of the dedifferentiation status. Subsequent studies are now required to access the use of these cytokines as therapeutic targets so the tumorigenic process may be abrogated in its initial steps, improving patients’ prognosis and survival.

Work sponsored by FEDER, POFC-COMPETE and the FCT grants PTDC/BBB-BQB/2450/2012 and SFRH/BD/33884/2009.

Citation Format: Carlos F. Rodrigues, Eurico Serrano, Marco Cunha, Maria I. Patrício, Mariana Val, João Fonseca, Célia Gomes, Antero Abrunhosa, Artur Paiva, Filomena Botelho, Lina Carvalho, Isabel M. Carreira, Alpoim Carmen. Deconstructing cancer stem cells: IL-6, G-CSF and Activin-A as mediators of stroma-orchestrated epithelial cells’ dedifferentiation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1915. doi:10.1158/1538-7445.AM2017-1915

Human plasma metabolomics in age-related macular degeneration (AMD) using nuclear magnetic resonance spectroscopy

PURPOSE

To differentiate the plasma metabolomic profile of patients with age related macular degeneration (AMD) from that of controls, by Nuclear Magnetic Resonance (NMR) spectroscopy.

METHODS

Two cohorts (total of 396 subjects) representative of central Portugal and Boston, USA phenotypes were studied. For each cohort, subjects were grouped according to AMD stage (early, intermediate and late). Multivariate analysis of plasma NMR spectra was performed, followed by signal integration and univariate analysis.

RESULTS

Small changes were detected in the levels of some amino acids, organic acids, dimethyl sulfone and specific lipid moieties, thus providing some biochemical information on the disease. The possible confounding effects of gender, smoking history and age were assessed in each cohort and found to be minimal when compared to that of the disease. A similar observation was noted in relation to age-related comorbidities. Furthermore, partially distinct putative AMD metabolite fingerprints were noted for the two cohorts studied, reflecting the importance of nutritional and other lifestyle habits in determining AMD metabolic response and potential biomarker fingerprints. Notably, some of the metabolite changes detected were noted as potentially differentiating controls from patients diagnosed with early AMD.

CONCLUSION

For the first time, this study showed metabolite changes in the plasma of patients with AMD as compared to controls, using NMR. Geographical origins were seen to affect AMD patients´ metabolic profile and some metabolites were found to be valuable in potentially differentiating controls from early stage AMD patients. Metabolomics has the potential of identifying biomarkers for AMD, and further work in this area is warranted.

Genetic and epigenetic characterization of the tumors in a patient with a tongue primary tumor, a recurrence and a pharyngoesophageal second primary tumor

Background

The choice of therapeutic modality for oral carcinoma in recurrent or second primary tumors remains controversial, as the treatment modalities available might be reduced by the treatment of the first tumor, and the overall survival is lower when compared with patients with a single or first tumor. Identifying biomarkers that predict the risk of relapse and the response to treatment is an emerging clinical issue.

Case presentation

A Caucasian 49-years-old man was treated with chemotherapy followed by chemoradiotherapy for a primary left side tongue tumor, achieving a complete response. After 49-months of follow-up, a local recurrence was diagnosed. After 3 months, a second primary tumor at the pharyngoesophageal region was detected. Genomic and epigenetic characterization of these three tumors was performed using array Comparative Genomic Hybridization, Multiplex Ligation-dependent Probe Amplification (MLPA) and Methylation Specific MLPA.

Results

The three tumors of this patient shared several imbalances in all chromosomes excluding chromosomes 9, 20 and 22, where genes related to important functional mechanisms of tumorigenesis are mapped. The shared genomic imbalances, such as losses at 1p, 2p, 3p, 4q, 5q, 6q, 7q, 8p, 10p, 11q, 12p, 12q, 13q, 15q, 16p, 16q, 17p, 17q, 18q, 19p, 19q, 21q and Xp and gains at 3q, 7q, 14q and 15q showed a common clonal origin for the diagnosed relapses.

We identified some chromosomal imbalances and genes mapped in the chromosomes 2, 3, 4, 6, 7, 11, 14, 17, 18 and 22 as putative linked to chemoradioresistance and chemoradiosensitivity. We also observed that gains in short arm of chromosomes 6, 7, 8 and 18 were acquired after treatment of the primary tumor. We identified losses of VHL gene and promoter methylation of WT1 and GATA5 genes, as predictors of relapses.

Conclusions

A common clonal origin for the diagnosed relapses was observed and we identified some putative candidate biomarkers of prognosis, relapse risk and treatment response that could guide the development of management strategies for these patients.

European registration process for Clinical Laboratory Geneticists in genetic healthcare

Tremendous progress in genetics and genomics led to a wide range of healthcare providers, genetic tests, and more patients who can benefit from these developments. To guarantee and improve the quality of genetic testing, a unified European-based registration for individuals qualified in biomedicine was realized. Therefore a Europe-wide recognition of the profession ‘European registered Clinical Laboratory Geneticist (ErCLG)' based on a syllabus of core competences was established which allows for harmonization in professional education. The ‘European Board of Medical Genetics division − Clinical Laboratory Geneticist' provides now since 3 years the possibility to register as an ErCLG. Applicants may be from all European countries and since this year also from outside of Europe. Five subtitles reflect the exact specialty of each ErCLG, who can reregister every 5 years. A previously not possible statistics based on ~300 individuals from 19 countries as holders of an ErCLG title provides interesting insights into the professionals working in human genetics. It could be substantiated that there are around twice as many females than males and that a PhD title was achieved by 80% of registered ErCLGs. Also most ErCLGs are still trained as generalists (66%), followed by such ErCLGs with focus on molecular genetics (23%); the remaining are concentrated either on clinical (6%), tumor (4%) or biochemical genetics (1%). In conclusion, besides MDs and genetic counselors/nurses an EU-wide recognition system for Clinical Laboratory Geneticist has been established, which strengthens the status of specialists working in human genetic diagnostics in Europe and worldwide.

MLPA analysis in a cohort of patients with autism

Background

Autism is a global neurodevelopmental disorder which generally manifests during the first 2 years and continues throughout life, with a range of symptomatic variations. Epidemiological studies show an important role of genetic factors in autism and several susceptible regions and genes have been identified. The aim of our study was to validate a cost-effective set of commercial Multiplex Ligation dependent Probe Amplification (MLPA) and methylation specific multiplex ligation dependent probe amplification (MS-MLPA) test in autistic children refered by the neurodevelopmental center and autism unit of a Paediatric Hospital.

Results

In this study 150 unrelated children with autism spectrum disorders were analysed for copy number variation in specific regions of chromosomes 15, 16 and 22, using MLPA. All the patients had been previously studied by conventional karyotype and fluorescence in situ hybridization (FISH) analysis for 15(q11.2q13) and, with these techniques, four alterations were identified. The MLPA technique confirmed these four and identified further six alterations by the combined application of the two different panels.

Conclusions

Our data show that MLPA is a cost effective straightforward and rapid method for detection of imbalances in a clinically characterized population with autism. It contributes to strengthen the relationship between genotype and phenotype of children with autism, showing the clinical difference between deletions and duplications.

Iodine deficiency a persisting problem: assessment of iodine nutrition and evaluation of thyroid nodular pathology in Portugal

BACKGROUND

The goal of eliminating iodine deficiency (ID) by the year 2000 has still not been achieved in several countries. More than 2 billion people worldwide (over 260 million school age children) remain ID. In Europe, there are still countries, such as Portugal, without national general population data on iodine nutrition (IN). This study aims at evaluating combined complementary data of the IN of the general population through urinary iodine concentration (UIC) and the thyroid histology profile from the inland region of Beira Interior (BI), in Portugal.

METHODS

UIC from a population sample of 214 volunteers (131 females and 83 males), with ages ranging from 8 to 97 years (mean 51.5 years ± SD 20.74 years), from BI was determined; the thyroid histology pattern in BI (6-year period) was evaluated; and the iodine content of the largest surface water reservoir of BI, never previously reported, was measured.

RESULTS

Median UIC of 62.6 μg/L was measured. Over 92 % of the population had UIC less than 100 μg/L. From 279 histology reports evaluated, the incidence of the different types of thyroid nodular pathology in BI was established. There were 60 histologic diagnoses of malignancy. The observed ratio of papillary to follicular carcinoma relatively close to 1 and the fairly high percentage of anaplastic carcinomas are characteristic of ID areas.

CONCLUSIONS

The findings of this first general population study on IN from the inland region of BI, Portugal, document significant ID. This problem, with its serious public health implications, could be corrected by having affordable iodised salt widely and generally available and by promoting a proactive population attitude generated by ample public information and educational programs as to the negative consequences of ID.

BIRC3 alterations in chronic and B-cell acute lymphocytic leukemia patients

Deletions within chromosome 11q22-23, are considered among the most common chromosomal aberrations in chronic lymphocytic leukemia (CLL), and are associated with a poor outcome. In addition to the ataxia telangiectasia mutated (ATM) gene, the baculoviral IAP repeat-containing 3 (BIRC3) gene is also located in the region. BIRC3 encodes a negative regulator of the non-canonical nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) protein. Disruption of BIRC3 is known to be restricted to CLL fludarabine-refractory patients. The aim of the present study was to determine the frequency of copy number changes of BIRC3 and to assess its association with two known predictors of negative CLL outcome, ATM and tumor protein 53 (TP53) gene deletions. To evaluate the specificity of BIRC3 alterations to CLL, BIRC3 copy numbers were assessed in 117 CLL patients in addition to 45 B-cell acute lymphocytic leukemia (B-ALL) patients. A commercially available multiplex ligation dependent probe amplification kit, which includes four probes for the detection of TP53 and four probes for ATM gene region, was applied. Interphase-directed fluorescence in situ hybridization was used to apply commercially available probes for BIRC3, ATM and TP53. High resolution array-comparative genomic hybridization was conducted in selected cases. Genetic abnormalities of BIRC3 were detected in 23/117 (~20%) of CLL and 2/45 (~4%) of B-ALL cases. Overall, 20 patients with CLL and 1 with B-ALL possessed a BIRC3 deletion, whilst 3 patients with CLL and 1 with B-ALL harbored a BIRC3 duplication. All patients with an ATM deletion also carried a BIRC3 deletion. Only 2 CLL cases possessed deletions in BIRC3, ATM and TP53 simultaneously. Evidently, the deletion or duplication of BIRC3 may be observed rarely in B-ALL patients. BIRC3 duplication may occur in CLL patients, for which the prognosis requires additional studies in the future. The likelihood that TP53 deletions occur simultaneously with BIRC3 and/or ATM aberrations is low. However, as ATM deletions may, but not always, associate with BIRC3 deletions, each region should be considered in the future diagnostics of CLL in order to aid treatment decisions, notably whether to treat with or without fludarabine.

A novel IGH@ gene rearrangement associated with CDKN2A/B deletion in young adult B-cell acute lymphoblastic leukemia

Acquired copy number changes are common in acute leukemia. They are reported as recurrent amplifications or deletions (del), and may be indicative of involvement of oncogenes or tumor suppressor genes in acquired disease, as well as serving as potential biomarkers for prognosis or as targets for molecular therapy. The present study reported a gain of copy number of 14q13 to 14q32, leading to immunoglobulin heavy chain locus splitting in a young adult female. To the best of our knowledge, this rearrangement has not been previously reported in B-cell acute lymphoblastic leukemia (ALL). Low resolution banding cytogenetics performed at the time of diagnosis revealed a normal karyotype. However, retrospective application of fluorescence in situ hybridization (FISH) banding and locus-specific FISH probes, as well as multiplex ligation-dependent probe amplification and high resolution array-comparative genomic hybridization, revealed previously hidden aberrations. Overall, a karyotype of 46, XX, del(9) (p21.3 p21.3),derivative(14) (pter-> q32.33:: q32.33-> q13 ::q32.33-> qter) was determined. The patient was treated according to the Polish Adult Leukemia Group protocol and achieved complete remission. The results of the present study indicate that a favorable prognosis is associated with these aberrations when the aforementioned treatment is administered.

A unique phenotype in a patient with a rare triplication of the 22q11.2 region and new clinical insights of the 22q11.2 microduplication syndrome: a report of two cases

Background

The rearrangements of the 22q11.2 chromosomal region, most frequently deletions and duplications, have been known to be responsible for multiple congenital anomaly disorders. These rearrangements are implicated in syndromes that have some phenotypic resemblances. While the 22q11.2 deletion, also known as DiGeorge/Velocardiofacial syndrome, has common features that include cardiac abnormalities, thymic hypoplasia, characteristic face, hypocalcemia, cognitive delay, palatal defects, velopharyngeal insufficiency, and other malformations, the microduplication syndrome is largely undetected. This is mainly because phenotypic appearance is variable, milder, less characteristic and unpredictable. In this paper, we report the clinical evaluation and follow-up of two patients affected by 22q11.2 rearrangements, emphasizing new phenotypic features associated with duplication and triplication of this genomic region.

Case Presentation

Patient 1 is a 24 year-old female with 22q11.2 duplication who has a heart defect (ostium secundum atrial septal defect) and supernumerary teeth (hyperdontia), a feature previously not reported in patients with 22q11.2 microduplication syndrome. Her monozygotic twin sister, who died at the age of one month, had a different heart defect (truncus arteriousus). Patient 2 is a 20 year-old female with a 22q11.2 triplication who had a father with 22q11.2 duplication. In comparison to the first case reported in the literature, she has an aggravated phenotype characterized by heart defects (restrictive VSD and membranous subaortic stenosis), and presented other facial dysmorphisms and urogenital malformations (ovarian cyst). Additionally, she has a hemangioma planum on the right side of her face, a feature of Sturge-Weber syndrome.

Conclusions

In this report, we described hyperdontia as a new feature of 22q11.2 microdeletion syndrome. Moreover, this syndrome was diagnosed in a patient who had a deceased monozygotic twin affected with a different heart defect, which corresponds to a phenotypic discordance never reported in the literature. Case 2 is the second clinical report of 22q11.2 triplication and presents an aggravated phenotype in contrast to the patient previously reported.

High rates of submicroscopic aberrations in karyotypically normal acute lymphoblastic leukemia

Background

Acute lymphoblastic leukemia (ALL) is not a single uniform disease. It consists of several subgroups with different cytogenetic and molecular genetic aberrations, clinical presentations and outcomes. Banding cytogenetics plays a pivotal role in the detection of recurrent chromosomal rearrangements and is the starting point of genetic analysis in ALL, still. Nowadays, molecular (cyto)genetic tools provide substantially to identify previously non-detectable, so-called cryptic chromosomal aberrations in ALL. However, ALL according to banding cytogenetics with normal karyotype - in short cytogenetically normal ALL (CN-ALL) - represent up to ~50 % of all new diagnosed ALL cases. The overall goal of this study was to identify and characterize the rate of cryptic alterations in CN-ALL and to rule out if one single routine approach may be sufficient to detect most of the cryptic alterations present.

Results

Sixty-one ALL patients with CN-ALL were introduced in this study. All of them underwent high resolution fluorescence in situ hybridization (FISH) analysis. Also DNA could be extracted from 34 ALL samples. These DNA-samples were studied using a commercially available MLPA (multiplex ligation-dependent probe amplification) probe set directed against 37 loci in hematological malignancies and/or array-comparative genomic hybridization (aCGH). Chromosomal aberrations were detected in 21 of 61 samples (~34 %) applying FISH approaches: structural abnormalities were present in 15 cases and even numerical ones were identified in 6 cases. Applying molecular approaches copy number alterations (CNAs) were detected in 27/34 samples. Overall, 126 CNAs were identified and only 34 of them were detectable by MLPA (~27 %). Loss of CNs was identified in ~80 % while gain of CNs was present in ~20 % of the 126 CNAs. A maximum of 13 aberrations was detected per case; however, only one aberration per case was found in 8 of all in detail studied 34 cases. Of special interest among the detected CNAs are the following new findings: del(15)(q26.1q26.1) including CHD2 gene was found in 20 % of the studied ALL cases, dup(18)(q21.2q21.2) with the DCC gene was present in 9 % of the cases, and the CDK6 gene in 7q21.2 was deleted in 12 % of the here in detail studied ALL cases.

Conclusions

In conclusion, high resolution molecular cytogenetic tools and molecular approaches like MLPA and aCGH need to be combined in a cost-efficient way, to identify disease and progression causing alterations in ALL, as majority of them are cryptic in banding cytogenetic analyses.

Electronic supplementary material

The online version of this article (doi:10.1186/s13039-015-0153-4) contains supplementary material, which is available to authorized users.

Prediction of Gestational Diabetes through NMR Metabolomics of Maternal Blood

Metabolic biomarkers of pre- and postdiagnosis gestational diabetes mellitus (GDM) were sought, using nuclear magnetic resonance (NMR) metabolomics of maternal plasma and corresponding lipid extracts. Metabolite differences between controls and disease were identified through multivariate analysis of variable selected (1)H NMR spectra. For postdiagnosis GDM, partial least squares regression identified metabolites with higher dependence on normal gestational age evolution. Variable selection of NMR spectra produced good classification models for both pre- and postdiagnostic GDM. Prediagnosis GDM was accompanied by cholesterol increase and minor increases in lipoproteins (plasma), fatty acids, and triglycerides (extracts). Small metabolite changes comprised variations in glucose (up regulated), amino acids, betaine, urea, creatine, and metabolites related to gut microflora. Most changes were enhanced upon GDM diagnosis, in addition to newly observed changes in low-Mw compounds. GDM prediction seems possible exploiting multivariate profile changes rather than a set of univariate changes. Postdiagnosis GDM is successfully classified using a 26-resonance plasma biomarker. Plasma and extracts display comparable classification performance, the former enabling direct and more rapid analysis. Results and putative biochemical hypotheses require further confirmation in larger cohorts of distinct ethnicities.

Cutis Aplasia as a clinical hallmark for the syndrome associated with 19q13.11 deletion: the possible role for UBA2 gene

BACKGROUND

Wide genome screening through array comparative genomic hybridization made possible the recognition of the novel 19q13.11 deletion syndrome. There are very few cases reported with this deletion, but clinically this condition seems to be recognizable by pre and postnatal growth retardation, microcephaly, developmental delay/intellectual disabilities, speech disturbance, hypospadias (in males) and signs of ectodermal dysplasia and cutis aplasia over the posterior occiput.

RESULTS

Using oligoarray CGH, a 4.6 Mb deletion in 19q13.11q13.12 was detected in a 23 year old female patient that presented clinical features previously associated with 19q13.11 deletion.

CONCLUSIONS

Our work reinforces the idea that a region encompassing four zinc finger genes is likely to be responsible for the syndrome, and that the difference in minor clinical manifestation depends on the genes present outside the minimal overlapping region proposed for this syndrome. We also review all cases described in the literature and discuss the correlation between haploinsufficiency of UBA2 gene and cutis aplasia present in the majority of the patients reported, and its importance as a clinical hallmark of 19q13.11 deletion syndrome, when associated with more common features like developmental delay, microcephaly, speech disturbance and hypospadias in males.

Novel Cryptic Rearrangements in Adult B-Cell Precursor Acute Lymphoblastic Leukemia Involving the MLL Gene

MLL (mixed-lineage-leukemia) gene rearrangements are typical for acute leukemia and are associated with an aggressive course of disease, with a worse outcome than comparable case, and thus require intensified treatment. Here we describe a 69-year-old female with adult B cell precursor acute lymphoblastic leukemia (BCP-ALL) with hyperleukocytosis and immunophenotype CD10- and CD19+ with cryptic MLL rearrangements. G-banding at the time of diagnosis showed a normal karyotype: 46,XX. Molecular cytogenetics using multitude multicolor banding (mMCB) revealed a complex rearrangement of the two copies of chromosome 11. However, a locus-specific probe additionally identified that the MLL gene at 11q23.3 was disrupted, and that the 5' region was inserted into the chromosomal sub-band 4q21; thus the aberration involved three chromosomes and five break events. Unfortunately, the patient died six months after the initial diagnosis from serious infections and severe complications. Overall, the present findings confirm that, by far not all MLL aberrations are seen by routine chromosome banding techniques and that fluorescence in situ hybridization (FISH) should be regarded as standard tool to access MLL rearrangements in patients with BCP-ALL.

Interstitial 287 kb deletion of 4p16.3 including FGFRL1 gene associated with language impairment and overgrowth

We report a male patient with developmental delay carrying an interstitial 4p16.3 deletion of 287 kb, disclosed by oligo array-CGH and inherited from his father with a similar but milder phenotype. This deletion is distal to the Wolf-Hirschhorn syndrome critical regions, but includes the FGFRL1 gene proposed to be a plausible candidate for part of the craniofacial characteristics of Wolf-Hirschhorn syndrome patients. However, the proband lacks the typical facial appearance of the syndrome, but exhibits overgrowth, dysfunction of temporomandibular articulation and a bicuspid aortic valve. Given the pattern of expression of the fibroblast growth factor receptor-like 1 and its involvement in bone and cartilage formation as well as in heart valve morphogenesis, we discuss the impact of its haploinsufficiency in the phenotype.

MLLT10 and IL3 rearrangement together with a complex four-way translocation and trisomy 4 in a patient with early T-cell precursor acute lymphoblastic leukemia: A case report

Cytogenetic classification of acute lymphoblastic leukemia (ALL) is primarily based on numerical and structural chromosomal abnormalities. In T-cell ALL (T-ALL), chromosomal rearrangements are identified in up to 70% of the patients while the remaining patients show a normal karyotype. In the present study, a 16-year-old male was diagnosed with T-precursor cell ALL and a normal karyotype after standard GTG-banding, was studied retrospectively (>10 years after diagnosis) in frame of a research project by molecular approaches. In addition to molecular cytogenetics, multiplex ligation-dependent probe amplification (MLPA) and high resolution array-comparative genomic hybridization (aCGH) were also applied. Thus, the following yet unrecognized balanced chromosomal aberrations were detected: der(3)t(3;5)(p23;q31.1), der(5)t(3;5)(p23;q35.3), der(5)t(5;10)(q31.1;p12.3) and der(10)t(5;10)(q35.3;p12.3). The oncogene MLLT10 was involved in this rearrangement as was the IL3 gene; in addition, trisomy 4 was present. All of these clonal aberrations were found in 40% of the cells. Even if this complex karyotype would have been identified at the time of diagnosis, most likely no other protocol of anticancer therapy (ALL-BFM 95) would have been applied. Three months after the end of a successful 2-year treatment, the patient suffered from isolated bone marrow relapse and died of sepsis during ALL-REZ-BFM protocol treatment.

Screening of copy number variants in the 22q11.2 region of congenital heart disease patients from the São Miguel Island, Azores, revealed the second patient with a triplication

Background

The rearrangements in the 22q11.2 chromosomal region, responsible for the 22q11.2 deletion and microduplication syndromes, are frequently associated with congenital heart disease (CHD). The present work aimed to identify the genetic basis of CHD in 87 patients from the São Miguel Island, Azores, through the detection of copy number variants (CNVs) in the 22q11.2 region. These structural variants were searched using multiplex ligation-dependent probe amplification (MLPA). In patients with CNVs, we additionally performed fluorescent in situ hybridization (FISH) for the assessment of the exact number of 22q11.2 copies among each chromosome, and array comparative genomic hybridization (array-CGH) for the determination of the exact length of CNVs.

Results

We found that four patients (4.6%; A to D) carried CNVs. Patients A and D, both affected with a ventricular septal defect, carried a de novo 2.5 Mb deletion of the 22q11.2 region, which was probably originated by inter-chromosomal (inter-chromatid) non-allelic homologous recombination (NAHR) events in the regions containing low-copy repeats (LCRs). Patient C, with an atrial septal defect, carried a de novo 2.5 Mb duplication of 22q11.2 region, which could have been probably generated during gametogenesis by NAHR or by unequal crossing-over; additionally, this patient presented a benign 288 Kb duplication, which included the TOP3B gene inherited from her healthy mother. Finally, patient B showed a 3 Mb triplication associated with dysmorphic facial features, cognitive deficit and heart defects, a clinical feature not reported in the only case described so far in the literature. The evaluation of patient B’s parents revealed a 2.5 Mb duplication in her father, suggesting a paternal inheritance with an extra copy.

Conclusions

This report allowed the identification of rare deletion and microduplication syndromes in Azorean CHD patients. Moreover, we report the second patient with a 22q11.2 triplication, and we suggest that patients with triplications of chromosome 22q11.2, although they share some characteristic features with the deletion and microduplication syndromes, present a more severe phenotype probably due to the major dosage of implicated genes.

Abstract 3027: Stromal cells-derived paracrine factors promote dedifferentiation of human lung carcinoma cells into cancer stem cells

Tumors are dynamic entities that act like organs in a perfect trading with the entire body. Through the employment of deceiving cellular and molecular strategies, they use the corporal machinery for the promotion of their survival and dissemination. The extensive crosstalk mediated by cytokines and chemokines overcome the inefficiency of the invasion-metastasis cascade, thus allowing the development of the often fatal metastatic disease. As heterogeneous entities, tumors are comprised of distinct cell populations. Cancer stem cells (CSCs) are a subset of notably chemo- and radiotherapy resistant malignant tumor cells with the capacity to drive tumorigenesis and metastases formation and eventually tumor relapse.

Lung cancer is a leading cause of death worldwide and its prevalence is increasing mostly due to sustained smoking habits and the accumulation of atmosphere pollutants. In this work hexavalent chromium [Cr(VI)] was the carcinogenic agent used considering its increasing occupational relevance. The non-malignant human bronchial epithelial airway system 2B (BEAS-2B) was malignantly transformed into the RenG2 cell line using low density culture in the presence of Cr(VI). A parallel control cellular system (Cont1) was produced under the same conditions, though, in the absence of Cr(VI). Two additional derivative cell lines, DRenG2 and DDRenG2, were attained following serial rounds of injections in immunocompromised mice. A panoply of techniques was used to characterize the attained cellular systems leading to the hypothesis of CSCs involvement in Cr(VI)-driven BEAS-2B malignant transformation. The sphere-formation assay readily confirmed our hypothesis as CSCs spheres were isolated only from the derivative cell lines (SC-DRenG2 and SC-DDRenG2 cells, respectively). Tumorigenic and RT-qPCR studies further supported the stem potential of the attained systems, suggesting that a dedifferentiation process featured its emergence during RenG2 derivation in nude mice. Using an elegant cell culture model that encompassed the prolonged co-culture of surgically isolated mice lumbar stromal cells with the RenG2 cells, we proved that RenG2 cells’ dedifferentiation was driven by paracrine factors released by the mouse fibroblasts, as they lost the RenG2's molecular signature and acquired a new one more close to that of both DRenG2 and SC-DRenG2. Finally, the key cytokines released by the stromal fibroblasts were identified in the conditioned media of such cultures.

CSCs formation boosted the malignant potential of our carcinoma cell population, providing them with increased resistance to therapeutic drugs. Also, the dedifferentiation process revealed to be essentially chemical and specie-unspecific, as human cells were able to dedifferentiate in response to mice cells-released cytokines.

Work sponsored by FEDER, POFC-COMPETE and the FCT grants PTDC/BBB-BQB/2450/2012 and SFRH/BD/33884/2009.

Citation Format: Carlos F D Rodrigues, Inês P. Rodrigues, Mariana Val, Lina Carvalho, Artur Paiva, Anatoly Zhitkovich, Isabel M. Carreira, Mª Carmen Alpoim. Stromal cells-derived paracrine factors promote dedifferentiation of human lung carcinoma cells into cancer stem cells. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3027. doi:10.1158/1538-7445.AM2014-3027

Human plasma stability during handling and storage: impact on NMR metabolomics

The stability of human plasma composition was investigated by NMR, considering different collection tubes, time at room temperature (RT), short- and long-term storage conditions and up to 5 consecutive freeze–thaw cycles.

Abstract 2603: Cancer stem cells and dedifferentiation: the stromal match-point

Bypassing all the research advances in the last decades, cancer remains as a major public health problem affecting more than 1.5 million (M) new individuals each year just in the USA, and killing more than 0.5 M. Recent research emphasized the major role of cancer stem cells (CSCs) in the metastatic disease, the main cause of cancer patients mortality. CSCs drive tumorigenesis and differentiation, contributing to tumors’ heterogeneity and to their relative chemo- and radiotherapy resistance and eventually relapse. Following CSCs identification, targeted therapeutic approaches have been developed to abolish them. However, CSCs can reemerge through dedifferentiation of tumor-committed stromal cells condemning this therapeutics. The mechanisms behind dedifferentiation are still unclear and are the main focus of our investigation.

Lung cancer is one of the main causes of cancer-related deaths worldwide. Its prevalence is increasing due to the widespread smoking habits and increasing accumulation of atmosphere pollutants. In this work hexavalent chromium [Cr(VI)] was selected as a model of cancer carcinogenesis mainly due to is increasing occupational relevance. The non-malignant human bronchial epithelial cell line BEAS-2B was malignantly transformed into the RenG2 system using low density culture in the presence of Cr(VI). A parallel control cell line (Cont1) was produced under the same conditions, though, in the absence of Cr(VI). Two additional cell lines (DRenG2 and DDRenG2) were attained following serial rounds of injection in nude mice. Metabolic studies using [18F]fluoro-2-deoxyglucose) and nuclear magnetic resonance spectroscopy performed in all the cell lines revealed a more glycolytic phenotype for the derivatives (DRenG2 and DDRenG2), compatible with a quiescent phenotype. Subsequent karyotype and real time PCR-based cellular characterization identified different cellular sub-populations within each cell line, strengthening the hypothesis on the CSCs presence. The sphere-formation assay, used to search for CSCs presence, revealed the presence of CSCs only DRenG2 and in DDRenG2 cell lines. This suggested that a dedifferentiation process featured the formation of CSCs during RenG2 derivation in nude mice. The involvement of mice stroma in this process was uncovered by surgical isolation of mouse stromal cells of the subcutaneous compartment and subsequent co-culture with RenG2 cells for 30-60 days (time needed to induce tumors in mice with RenG2), which resulted in the emergence of a CSCs sub-population. A cytokine multiplex array analysis performed in the conditioned medium of the co-cultured cells in parallel with comparative genome hybridization array (aCGH) analysis performed in all the cell lines under study revealed a panel of potential paracrine orchestrators of this stromal-induced dedifferentiation process.

Citation Format: Carlos F. Rodrigues, Mariana Val, Inês P. Rodrigues, Susana Ferreira, Filomena Botelho, José Ramalho, Anatoly Zhitkovich, Isabel M. Carreira, Carmen Alpoim. Cancer stem cells and dedifferentiation: the stromal match-point. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2603. doi:10.1158/1538-7445.AM2013-2603

Inv21p12q22del21q22 and intellectual disability

Chromosomal rearrangements are common in humans. Pericentric inversions are among the most frequent aberrations (1-2%). Most inversions are balanced and do not cause problems in carriers unless one of the breakpoints disrupts important functional genes, has near submicroscopic copy number variants or hosts "cryptic" complex chromosomal rearrangements. Pericentric inversions can lead to imbalance in offspring. Less than 3% of Down syndrome patients have duplication as a result of parental pericentric inversion of chromosome 21. We report a family with an apparently balanced pericentric inversion of chromosome 21. The proband, a 23-year-old female was referred for prenatal diagnosis at 16 weeks gestation because of increased nuchal translucency. She has a familial history of Down's syndrome and moderate intellectual disability, a personal history of four spontaneous abortions and learning difficulties. Peripheral blood and amniotic fluid samples were collected to perform proband's and fetus' cytogenetic analyses. Additionally, another six family members were evaluated and cytogenetic analysis was performed. Complementary FISH and MLPA studies were carried out. An apparent balanced chromosome 21 pericentric inversion was observed in four family members, two revealed a recombinant chromosome 21 with partial trisomy, and one a full trisomy 21 with an inverted chromosome 21. Array CGH analysis was performed in the mother and the brother's proband. MLPA and aCGH studies identified a deletion of about 1.7 Mb on the long arm of inverted chromosome 21q22.11. We believe the cause of the intellectual disability/learning difficulties observed in the members with the inversion is related to this deletion. The recombinant chromosome 21 has a partial trisomy including the DSCR with no deletion. The risk for carriers of having a child with multiple malformations/intellectual disability is about 30% depending on whether and how this rearrangement interferes with meiosis.

High resolution melting: improvements in the genetic diagnosis of hypertrophic cardiomyopathy in a Portuguese cohort

BACKGROUND

Hypertrophic Cardiomyopathy (HCM) is a complex myocardial disorder with a recognized genetic heterogeneity. The elevated number of genes and mutations involved in HCM limits a gene-based diagnosis that should be considered of most importance for basic research and clinical medicine.

METHODOLOGY

In this report, we evaluated High Resolution Melting (HRM) robustness, regarding HCM genetic testing, by means of analyzing 28 HCM-associated genes, including the most frequent 4 HCM-associated sarcomere genes, as well as 24 genes with lower reported HCM-phenotype association. We analyzed 80 Portuguese individuals with clinical phenotype of HCM allowing simultaneously a better characterization of this disease in the Portuguese population.

RESULTS

HRM technology allowed us to identify 60 mutated alleles in 72 HCM patients: 49 missense mutations, 3 nonsense mutations, one 1-bp deletion, one 5-bp deletion, one in frame 3-bp deletion, one insertion/deletion, 3 splice mutations, one 5'UTR mutation in MYH7, MYBPC3, TNNT2, TNNI3, CSRP3, MYH6 and MYL2 genes. Significantly 22 are novel gene mutations.

CONCLUSIONS

HRM was proven to be a technique with high sensitivity and a low false positive ratio allowing a rapid, innovative and low cost genotyping of HCM. In a short return, HRM as a gene scanning technique could be a cost-effective gene-based diagnosis for an accurate HCM genetic diagnosis and hopefully providing new insights into genotype/phenotype correlations.

UPLC-MS metabolic profiling of second trimester amniotic fluid and maternal urine and comparison with NMR spectral profiling for the identification of pregnancy disorder biomarkers

We report on the first untargeted UPLC-MS study of 2nd trimester maternal urine and amniotic fluid (AF), to investigate the possible metabolic effects of fetal malformations (FM), gestational diabetes mellitus (GDM) and preterm delivery (PTD). For fetal malformations, considerable metabolite variations were identified in AF and, to a lesser extent, in urine. Using validated PLS-DA models and statistical correlations between UPLC-MS data and previously acquired NMR data, a metabolic picture of fetal hypoxia, enhanced gluconeogenesis, TCA activity and hindered kidney development affecting FM pregnancies was reinforced. Moreover, changes in carnitine, pyroglutamate and polyols were newly noted, respectively, reflecting lipid oxidation, altered placental amino acid transfer and alterations in polyol pathways. Higher excretion of conjugated products in maternal urine was seen suggesting alterations in conjugation reactions. For the pre-diagnostic GDM group, no significant changes were observed, either considering amniotic fluid or maternal urine, whereas, for the pre-PTD group, some newly observed changes were noted, namely, the decrease of particular amino acids and the increase of an hexose (possibly glucose), suggesting alteration in placental amino acid fluxes and a possible tendency for hyperglycemia. This work shows the potential of UPLC-MS for the study of fetal and maternal biofluids, particularly when used in tandem with comparable NMR data. The important roles played by sampling characteristics (e.g. group dimensions) and the specific experimental conditions chosen for MS methods are discussed.