Human Satellite 1A analysis provides evidence of pericentromeric transcription.

BACKGROUND: Pericentromeric regions of human chromosomes are composed of tandem-repeated and highly organized sequences named satellite DNAs. Human classical satellite DNAs are classified into three families named HSat1, HSat2, and HSat3, which have historically posed a challenge for the assembly of the human reference genome where they are misrepresented due to their repetitive nature. Although being known for a long time as the most AT-rich fraction of the human genome, classical satellite HSat1A has been disregarded in genomic and transcriptional studies, falling behind other human satellites in terms of functional knowledge. Here, we aim to characterize and provide an understanding on the biological relevance of HSat1A. RESULTS: The path followed herein trails with HSat1A isolation and cloning, followed by in silico analysis. Monomer copy number and expression data was obtained in a wide variety of human cell lines, with greatly varying profiles in tumoral/non-tumoral samples. HSat1A was mapped in human chromosomes and applied in in situ transcriptional assays. Additionally, it was possible to observe the nuclear organization of HSat1A transcripts and further characterize them by 3' RACE-Seq. Size-varying polyadenylated HSat1A transcripts were detected, which possibly accounts for the intricate regulation of alternative polyadenylation. CONCLUSION: As far as we know, this work pioneers HSat1A transcription studies. With the emergence of new human genome assemblies, acrocentric pericentromeres are becoming relevant characters in disease and other biological contexts. HSat1A sequences and associated noncoding RNAs will most certainly prove significant in the future of HSat research.

Assessment of Water Quality Parameters and their Seasonal Behaviour in a Portuguese Water Supply System: a 6-year Monitoring Study.

Water quality monitoring is a fundamental tool in the management of freshwater resources. The purpose of monitoring is to provide meaningful quality data for local action planning and catchment-wide decision making. The assessment of water quality is crucial to guarantee the efficient operation of the Water Treatment Plants (WTPs), promoting health conditions and contributing for a more sustainable urban water cycle. In accordance, the objective of this study was to evaluate key target chemical and microbiological water quality parameters, some of them already monitored within Portuguese/EU legal framework and others still not regulated, but with environmental and human heath relevance. A local monitoring database model, using a 6-year period (from 2014 to 2019) of water quality data, regarding water samples collected on representative sampling locations covering the freshwater abstraction sites, conventional WTPs and distribution network was assessed. This work provides new knowledge regarding occurrence and seasonal behaviour for both microbiological and chemical water quality parameters, essential to understand/manage the water supply system. Additionally, relationships between the target variables were also assessed. Particularly, strong correlations were identified between TOC and THMs formation at distribution network (r = 0.69; p ≤ 0.001); nitrates were the water quality parameter that revealed the best correlation between surface water source and treated water (r = 0.81; p ≤ 0.001), suggesting that treatment yield/performance is dependent on surface water load. The local and continuous monitoring of water systems are crucial to implement new approaches to guarantee the best quality of drinking water throughout the supply system.

FA-SAT ncRNA interacts with PKM2 protein: depletion of this complex induces a switch from cell proliferation to apoptosis.

FA-SAT is a highly conserved satellite DNA sequence transcribed in many Bilateria species. To disclose the cellular and functional profile of FA-SAT non-coding RNAs, a comprehensive experimental approach, including the transcripts location in the cell and in the cell cycle, the identification of its putative protein interactors, and silencing/ectopic expression phenotype analysis, was performed. FA-SAT non-coding RNAs play a nuclear function at the G1 phase of the cell cycle and the interactomic assay showed that the PKM2 protein is the main interactor. The disruption of the FA-SAT non-coding RNA/PKM2 protein complex, by the depletion of either FA-SAT or PKM2, results in the same phenotype-apoptosis, and the ectopic overexpression of FA-SAT did not affect the cell-cycle progression, but promotes the PKM2 nuclear accumulation. Overall, our data first describe the importance of this ribonucleoprotein complex in apoptosis and cell-cycle progression, what foresees a promising novel candidate molecular target for cancer therapy and diagnosis.

Future Perspectives in Detecting EGFR and ALK Gene Alterations in Liquid Biopsies of Patients with NSCLC.

Non-small-cell lung cancer (NSCLC) is a major cause of death worldwide. Alterations in such genes as EGFR and ALK are considered important biomarkers in NSCLC due to the existence of targeted therapies with specific tyrosine kinase inhibitors (TKIs). However, specific resistance-related mutations can occur during TKI treatment, which often result in therapy inefficacy. Liquid biopsies arise as a reliable tool for the early detection of these types of alterations, allowing a non-invasive follow-up of the patients. Furthermore, they can be essential for cancer screening, initial diagnosis and to check surgery success. Despite the great advantages of liquid biopsies in NSCLC and the high input that next-generation sequencing (NGS) approaches can provide in this field, its use in oncology is still limited. With improvement of assay sensitivity and the establishment of clinical guidelines for liquid biopsy analysis, it is expected that they will be used in routine procedures. This review focuses on the usefulness of liquid biopsies of NSCLC patients as a means to detect alterations in EGFR and ALK genes and in disease management, highlighting the impact of NGS methods.

Genomic Tackling of Human Satellite DNA: Breaking Barriers through Time.

(Peri)centromeric repetitive sequences and, more specifically, satellite DNA (satDNA) sequences, constitute a major human genomic component. SatDNA sequences can vary on a large number of features, including nucleotide composition, complexity, and abundance. Several satDNA families have been identified and characterized in the human genome through time, albeit at different speeds. Human satDNA families present a high degree of sub-variability, leading to the definition of various subfamilies with different organization and clustered localization. Evolution of satDNA analysis has enabled the progressive characterization of satDNA features. Despite recent advances in the sequencing of centromeric arrays, comprehensive genomic studies to assess their variability are still required to provide accurate and proportional representation of satDNA (peri)centromeric/acrocentric short arm sequences. Approaches combining multiple techniques have been successfully applied and seem to be the path to follow for generating integrated knowledge in the promising field of human satDNA biology.

Are there gross motor coordination spurts during mid-childhood?

OBJECTIVES: The aims of this study were (1) to identify the timing of the mid-growth spurt (MGS) in stature in children and (2) to identify gross motor coordination (GMC) spurts when aligned by the age of attainment of the MGS (aMGS). METHODS: Stature, weight, and GMC were measured in 245 Portuguese children followed annually from 6 to 10 years. GMC was assessed and to estimate children's MGS in stature as well as GMC spurts in each of the four tests aligned by aMGS, we used a nonsmoothed polynomial methodology. RESULTS: In boys, the aMGS was attained at 7.8 years, whereas in girls it was 8.0 years. In boys, the peak MGS was 6.2 cm∙yr-1 and in girls it was 6.4 cm∙yr-1 . In boys, the peak for walking backwards (WB) occurred 18 months before aMGS (14.9-points∙yr-1 ), jumping sideways (JS) was 12 months after aMGS (13.5-points∙yr-1 ), hopping on one leg (HO) was 18 months before aMGS (11.7-points∙yr-1 ), and shifting platform (SP) was 12 months before aMGS (6.8-points∙yr-1 ). In girls, WB spurts occurred 12 months after aMGS (13.3-points∙yr-1 ), JS was 12 months before aMGS (10.5-points∙yr-1 ), HO was coincident with aMGS (10.4-points∙yr-1 ), and SP was 18 as well as 12 months before aMGS (7.2-points∙yr-1 ). No differences were observed in the mean peak spurts between sexes in the GMC tests. CONCLUSIONS: Boys and girls reached their MGS in stature at about the same chronological age. Spurts in GMC did not express themselves in the same biological timing relative to aMGS in stature, and there are sex differences.

Modelling the dynamics of children's gross motor coordination.

This study modelled children's gross motor coordination, investigated sex-differences and identified the effects of fixed and dynamic correlates on motor coordination development. A total of 344 Portuguese children (170 girls), from 6 age cohorts (5 to 9 years of age), were followed consecutively for three years (age range 5 to 11 years) using a mixed-longitudinal cohort design. Birth weight, hand dominance and socioeconomic status (SES) were identified. Gross motor coordination, body mass index, physical fitness (PF) and physical activity (PA) were assessed annually. A sequence of multilevel hierarchical linear models were developed. Model 1 found that age, age2, sex, sex-by-age and sex-by-age2 were significant predictors (p < 0.05) of gross motor coordination. Boys outperformed girls from 6 years of age onwards. Model 2 found a cohort effect (p < 0.05). Model 3 found that right handers were more coordinated (p < 0.05). When the confounders of body mass index, PF and PA were added to the model (Model 4) it was found that boys and girls had parallel trajectories in their gross motor coordination development. In conclusion children with increasing body mass index were less coordinated, while those who were stronger and more agile had steeper trajectories of gross motor coordination with age.

Comparative Chromosome Painting in Genets (Carnivora, Viverridae, Genetta), the Only Known Feliforms with a Highly Rearranged Karyotype.

Mammalian carnivores have been extensively studied by cross-species chromosome painting, which indicated a high degree of karyotypic conservatism in the cat-like suborder Feliformia relative to the ancestral carnivore karyotype (ACK). The first exception to this high degree of karyotypic conservation in feliforms was recently confirmed in genets, mesocarnivores belonging to the basal family Viverridae. Here, we present a comparative analysis of the chromosome rearrangements among 2 subspecies of the small-spotted genet Genetta genetta (the Iberian nominate and the Arabian grantii) and the panther genet G. maculata, the 2 most common and widespread genets, using whole-chromosome paints from the domestic cat (Felis catus). The chromosome homology maps and the presence of numerous interstitial telomeric sites in both genet species strengthen the hypothesis that a highly rearranged karyotype compared to the ACK may occur throughout Genetta. The karyotype of G. maculata appears to have undergone more rearrangements than that of G. genetta, which is an older lineage. Notably, we identified a tandem fusion distinguishing G. g. genetta and G. g.grantii. As G. g. grantii is morphologically and genetically distinctive, and tandem fusions have been associated with substantial postzygotic isolation in mammals, this cytogenetic finding flags the subspecies for future taxonomic investigations.

Identifying the best body-weight-status index associated with metabolic risk in youth.

This study investigated the association of six different anthropometric markers with metabolic syndrome to find the most suited to predict children at risk. Sample comprises 1324 Portuguese youth (701 girls, 623 boys), aged 10-17 years. Six anthropometric markers were included: body mass index (BMI), BMI z-score, tri-ponderal index (TPI), waist circumference (WC), WC/height ratio (WC/H), and WC/H adjusted ratio (WC/Hadj ). A standardized metabolic risk score (zMR) was computed by summing of standardized values for fasting glucose, triglycerides, high-density lipoprotein cholesterol, and mean arterial blood pressure. The associations between zMR and anthropometric markers were assessed using univariate and multivariate analyses. Receiver operating characteristic (ROC) curve analysis was used to identify the optimal values that best predict metabolic risk of each anthropometric marker. Among the studied predictors, BMI z-score, followed by BMI and WC, was most highly associated with zMR, while WC/Hadj was the weakest predictor. ROC analyses showed significant AUCs for all markers, yet the discrimination was poor (AUCs from 0.60 to 0.68), with sensitivity ranging from 45.5% to 67.5% and specificity from 72.6% to 81.9%. The optimal cut-off values to predict metabolic risk were 1.62, 23.1 kg/m2 , 71.0 cm, 18.0 kg/m3 , 0.47, and 0.50, for BMI z-score, BMI, WC, TPI, WC/H, and WC/Hadj , respectively. BMI z-score, followed by BMI and WC, were the most relevant anthropometric markers to predict metabolic risk in youth, while WC/Hadj was the worst predictor. Results suggest that anthropometric markers should continue to be used as clinical tools to identify youth at risk.

A mixed-longitudinal study of children's growth, motor development and cognition. Design, methods and baseline results on sex-differences.

BACKGROUND: There is a renewed interest in longitudinal studies which link children's growth, motor and cognition development. This is important for both educational outcomes and identification of children who are at risk. AIM: To identify cross-sectional sex-differences. SUBJECTS AND METHODS: In total, 1166 Portuguese children, aged 4-11 years, were recruited into the Growth, Motor Development and Cognition Study (GMDC-Vouzela study). Measures included: anthropometry, gestational development, motor coordination, cognitive performance, laterality, physical fitness, metabolic syndrome risk, lifestyle characteristics and environmental exposures. Analysis of covariance was used to compare outcomes between boys and girls, adjusting for chronological age. RESULTS: Most variables did not show significant differences between the sexes (p > 0.05). However, girls had more body fat mass than boys (p < 0.05) and boys were significantly heavier at birth (p < 0.05); furthermore, boys outperformed girls in a hopping high coordination test (p < 0.001) and were more physically fit (p < 0.05). CONCLUSIONS: Baseline results from the GMDC-Vouzela study indicate the dynamic relationships between children's biological and environmental characteristics. They also highlight lifestyle traits that will most likely effect subsequent growth, motor and cognitive development.

Familial resemblance in gross motor coordination. The Peruvian Sibling Study on Growth and Health.

BACKGROUND: The development of gross motor coordination (GMC) is governed by biological and environmental factors whose effect sizes are still unclear. AIM: To investigate sibling resemblance in GMC, as well as biological and environmental correlates of GMC among Peruvian children. MATERIALS AND METHODS: The sample comprised 1256 biological siblings (6-15 years old), from three geographical areas of Peru. GMC was assessed using the Korperkoordinationtest für Kinder (KTK) test battery. Anthropometry, biological maturation and physical fitness (PF) were also measured. Multilevel modelling was performed using Stata 14 software. RESULTS: In general, sister-sister pairs (SS) showed the highest resemblance in GMC (ρ = 0.24) compared to brother-sister (BS) (ρ = 0.10) and brother-brother (BB) pairs (ρ = 0.07). On average, BB pairs had higher GMC than SS pairs and older siblings had higher GMC than younger siblings. Further, those with lower body mass index (BMI) and higher PF had higher GMC. There was also a significant interaction between age and PF with GMC. Siblings from the rainforest region demonstrated higher GMC than those from sea level and high-altitude siblings demonstrated lower GMC than their sea-level peers. CONCLUSION: These results demonstrate statistically significant sibling resemblance in GMC. Age, BMI, PF and geographical area were significant correlates of GMC.

A multi-level analysis of individual- and school-level correlates of physical fitness in children.

BACKGROUND: Children's physical fitness is potentially influenced by biological, behavioural and environmental factors. AIM: To investigate the importance of individual-level and school-level characteristics in explaining variation in children's physical fitness. SUBJECTS AND METHODS: The sample comprised 354 Portuguese children, aged 5-10 years. Physical fitness [(handgrip (HG) strength, standing long jump (SLJ), shuttle-run (SR), total physical fitness score (PFz)], gross motor coordination (GMC) and body mass index (BMI) were assessed. Moderate-to-vigorous physical activity (MVPA) was objectively monitored; birth weight and socio-economic status (SES) were obtained by questionnaire. School contexts were assessed via an objective audit. Multilevel models using the Bayesian approach were used. RESULTS: Age was positively associated with HG, SLJ and PFz (p < 0.05); BMI was positively associated with HG (p < 0.05) and GMC with all physical fitness components (p < 0.05); MVPA was only associated with PFz (p < 0.05); children with level A SES outperformed those with level C SES in HG (p < 0.05), but those with level B SES outperformed their level A SES peers in SR (p < 0.05). Within the school context, no equipment for physical education was negatively associated with HG (p < 0.05). CONCLUSION: In the primary school years, individual-level characteristics were more important than the school context in explaining variations in physical fitness.

Multilevel modelling of somatotype components: the Portuguese sibling study on growth, fitness, lifestyle and health.

BACKGROUND: Somatotype is a complex trait influenced by different genetic and environmental factors as well as by other covariates whose effects are still unclear. AIMS: To (1) estimate siblings' resemblance in their general somatotype; (2) identify sib-pair (brother-brother (BB), sister-sister (SS), brother-sister (BS)) similarities in individual somatotype components; (3) examine the degree to which between and within variances differ among sib-ships; and (4) investigate the effects of physical activity (PA) and family socioeconomic status (SES) on these relationships. SUBJECTS AND METHODS: The sample comprises 1058 Portuguese siblings (538 females) aged 9-20 years. Somatotype was calculated using the Health-Carter method, while PA and SES information was obtained by questionnaire. Multi-level modelling was done in SuperMix software. RESULTS: Older subjects showed the lowest values for endomorphy and mesomorphy, but the highest values for ectomorphy; and more physically active subjects showed the highest values for mesomorphy. In general, the familiality of somatotype was moderate (ρ = 0.35). Same-sex siblings had the strongest resemblance (endomorphy: ρSS > ρBB > ρBS; mesomorphy: ρBB = ρSS > ρBS; ectomorphy: ρBB > ρSS > ρBS). For the ectomorphy and mesomorphy components, BS pairs showed the highest between sib-ship variance, but the lowest within sib-ship variance; while for endomorphy BS showed the lowest between and within sib-ship variances. CONCLUSIONS: These results highlight the significant familial effects on somatotype and the complexity of the role of familial resemblance in explaining variance in somatotypes.

The Oporto mixed-longitudinal growth, health and performance study. Design, methods and baseline results.

BACKGROUND: Studies concerning child and adolescent growth, development, performance and health aimed at the multiple interactions amongst this complex set of variables are not common in the Portuguese speaking countries. AIM: The aim of this paper is to address the key ideas, methodology and design of the Oporto Growth, Health and Performance Study (OGHPS). SUBJECTS AND METHODS: The OGHPS is a multidisciplinary mixed-longitudinal study whose main purpose is to examine the multiple interactions among biological, environmental and lifestyle indicators that affect growth, development, health and performance of Portuguese adolescents aged 10-18 years old. RESULTS: This study briefly presents baseline results for growth, physical fitness and lifestyle behaviours for those participating in the cross-sectional sample (n ≈ 8000). Approximately 30% were over-fat or obese. On average, boys were more physically fit and active than girls. Few adolescents meet the guidelines for sleep duration (≈10%) and eating habits (16.2-24.8%), while 76-85% meet the recommended levels of moderate-to-vigorous physical activity. CONCLUSIONS: The OGHPS has an innovative approach due to its mixed-longitudinal design and the broad array of variables. Furthermore, subsequent analyses of the longitudinal data will enable a detailed exploration of important factors affecting the growth trajectories of health and performance variables and will also help to identify some of the most opportune times for interventions in terms of health behaviours.

Classical and Molecular Cytogenetics of the Panther Genet Genetta maculata (Mammalia, Carnivora, Viverridae).

Genets (Genetta) are a genus of African mammalian carnivorans with 14 currently recognized species, although taxonomic uncertainties remain, particularly regarding the number of species within the large-spotted genet complex. This study presents the first banded karyotype and molecular cytogenetic analysis of a genetically identified panther genet, Genetta maculata, the most common and widespread taxon of the large-spotted genet complex, with a wide distribution in sub-Saharan Africa. Sampled in Gauteng Province, South Africa, it could be assigned to the subspecies G. m. letabae on geographic grounds and had a similar karyotype (2n = 52, FNa = 96) to those published for a panther genet from Ethiopia and for the West African large-spotted genet G. pardina. Notably, the specimen had a different autosomal morphology (2 acrocentric chromosomes) from that previously attributed to letabae (a single acrocentric chromosome), but the latter assignment was uncertain because the studied individuals were captive born and assigned based solely on a presumed origin in the former Transvaal Province of South Africa. Fluorescence in situ hybridization with a telomere repeat probe revealed the presence of telomeric sequences in the centromeres of most chromosomes, the so-called interstitial telomeric sites (ITSs). Since genets seem to have a unique, highly rearranged karyotype among feliforms and relatively low interspecific karyotypic variation, and considering the known instability of ITSs, we suggest that the large amount of ITSs found here might be due to evolutionarily recent extensive genomic rearrangements. This study provides cytogenetic information that contributes to our understanding of chromosomal variation and genomic rearrangements in genets, and valuable baseline data for future studies of karyotype evolution in carnivores in general and viverrids in particular.

The puzzling character of repetitive DNA in Phodopus genomes (Cricetidae, Rodentia).

Three novel repetitive DNA sequences are described, presenting a similar heterochromatic chromosomal location in two hamster species: Phodopus roborovskii and Phodopus sungorus (Cricetidae, Rodentia). Namely, two species-specific repetitive sequences (PROsat from P. roborovskii and PSUchr1sat from P. sungorus) surrounding a third one (PsatDNA), that is shared by both hamster genomes. Fiber-FISH analyses revealed that PROsat intermingles with PsatDNA in P. roborovskii and PSUchr1sat intermingles with PsatDNA in P. sungorus. A model explaining the evolution of this intricate chromosomal distribution is proposed, which can explain better the evolution of these very derivative genomes (in comparison to the ancestral Muroidea). The most plausible evolutionary scenario seems to be the expansion of a number of repeats into other's domain, most probably resulting in its intermingling, followed by the subsequent spread of these complex repeats from a single chromosomal location to other chromosomes. Evidences of an association between repetitive sequences and the chromosome evolution process were observed, namely for PROsat. Most probably, the evolutionary breakpoints that shaped PRO and PSU chromosomes (pericentric inversions and fusions) occurred within the boundaries of PROsat blocks in the ancestor. The repeats high diversity at the heterochromatic regions of Phodopus chromosomes, together with its complex organization, suggests that these species are important models for evolutionary studies, namely in the investigation of a possible relationship between repetitive sequences and the occurrence of chromosomal rearrangements and consequently, in genome evolution.

Satellite non-coding RNAs: the emerging players in cells, cellular pathways and cancer.

For several decades, transcriptional inactivity was considered as one of the particular features of constitutive heterochromatin and, therefore, of its major component, satellite DNA sequences. However, more recently, succeeding evidences have demonstrated that these sequences can indeed be transcribed, yielding satellite non-coding RNAs with important roles in the organization and regulation of genomes. Since then, several studies have been conducted, trying to understand the function(s) of these sequences not only in the normal but also in cancer genomes. It is thought that the association between cancer and satncRNAs is mostly due to the influence of these transcripts in the genome instability, a hallmark of cancer. The few reports on satellite DNA transcription in cancer contexts point to its overexpression; however, this scenario may be far more complex, variable, and influenced by a number of factors and the exact role of satncRNAs in the oncogenic process remains poorly understood. The greater is the knowledge on the association of satncRNAs with cancer, the greater would be the opportunity to assist cancer treatment, either by the design of effective therapies targeting these molecules or by using them as biomarkers in cancer diagnosis, prognosis, and with predictive value.

A methodological approach to short-term tracking of youth physical fitness: the Oporto Growth, Health and Performance Study.

In this paper, three different statistical approaches were used to investigate short-term tracking of cardiorespiratory and performance-related physical fitness among adolescents. Data were obtained from the Oporto Growth, Health and Performance Study and comprised 1203 adolescents (549 girls) divided into two age cohorts (10-12 and 12-14 years) followed for three consecutive years, with annual assessment. Cardiorespiratory fitness was assessed with 1-mile run/walk test; 50-yard dash, standing long jump, handgrip, and shuttle run test were used to rate performance-related physical fitness. Tracking was expressed in three different ways: auto-correlations, multilevel modelling with crude and adjusted model (for biological maturation, body mass index, and physical activity), and Cohen's Kappa (κ) computed in IBM SPSS 20.0, HLM 7.01 and Longitudinal Data Analysis software, respectively. Tracking of physical fitness components was (1) moderate-to-high when described by auto-correlations; (2) low-to-moderate when crude and adjusted models were used; and (3) low according to Cohen's Kappa (κ). These results demonstrate that when describing tracking, different methods should be considered since they provide distinct and more comprehensive views about physical fitness stability patterns.

Differences in motor performance between children and adolescents in Mozambique and Portugal: impact of allometric scaling.

BACKGROUND: Children from developed and developing countries have different anthropometric characteristics which may affect their motor performance (MP). AIM: To use the allometric approach to model the relationship between body size and MP in youth from two countries differing in socio-economic status-Portugal and Mozambique. SUBJECTS AND METHODS: A total of 2946 subjects, 1280 Mozambicans (688 girls) and 1666 Portuguese (826 girls), aged 10-15 years were sampled. Height and weight were measured and the reciprocal ponderal index (RPI) was computed. MP included handgrip strength, 1-mile run/walk, curl-ups and standing long jump tests. A multiplicative allometric model was adopted to adjust for body size differences across countries. RESULTS: Differences in MP between Mozambican and Portuguese children exist, invariably favouring the latter. The allometric models used to adjust MP for differences in body size identified the optimal body shape to be either the RPI or even more linear, i.e. approximately (height/mass(0.25)). Having adjusted the MP variables for differences in body size, the differences between Mozambican and Portuguese children were invariably reduced and, in the case of grip strength, reversed. CONCLUSION: These results reinforce the notion that significant differences exist in MP across countries, even after adjusting for differences in body size.

Cytogenetic Assessment of the Rat Cell Line CLS-ACI-1: An in vitro Cell Model for Mycn Overexpression.

Breast cancer is a complex and heterogeneous disease, and the establishment of cell models in order to properly study the disease at the molecular and cellular level is of utmost importance. Here, we present the cytogenetic characterization and gene expression analysis of the tumoral mammary rat cell line CLS-ACI-1. The use of banding and molecular cytogenetic techniques allowed the description of the complex CLS-ACI-1 karyotype and the identification of breakpoints in clonal chromosome rearrangements. Moreover, a Mycn and Erbb2 comparative expression analysis by RT-qPCR was performed, revealing a high expression level of Mycn in CLS-ACI-1 cells. Moreover, a considerable number of putative mutated genes and chromosome alterations detected through cytogenetic analysis seem to be in the MYCN biological network. Therefore, the CLS-ACI-1 cell line is presented as a promising cell model for the study of the role of MYCN in breast cancer and also as a tool for developing appropriate cancer therapies, namely for Mycn targeting.