Combining the amplification refractory mutation system and high-resolution melting analysis for KRAS mutation detection in clinical samples.

The success of personalized medicine depends on the discovery of biomarkers that allow oncologists to identify patients that will benefit from a particular targeted drug. Molecular tests are mostly performed using tumor samples, which may not be representative of the tumor's temporal and spatial heterogeneity. Liquid biopsies, and particularly the analysis of circulating tumor DNA, are emerging as an interesting means for diagnosis, prognosis, and predictive biomarker discovery. In this study, the amplification refractory mutation system (ARMS) coupled with high-resolution melting analysis (HRMA) was developed for detecting two of the most relevant KRAS mutations in codon 12. After optimization with commercial cancer cell lines, KRAS mutation screening was validated in tumor and plasma samples collected from patients with pancreatic ductal adenocarcinoma (PDAC), and the results were compared to those obtained by Sanger sequencing (SS) and droplet digital polymerase chain reaction (ddPCR). The developed ARMS-HRMA methodology stands out for its simplicity and reduced time to result when compared to both SS and ddPCR but showing high sensitivity and specificity for the detection of mutations in tumor and plasma samples. In fact, ARMS-HRMA scored 3 more mutations compared to SS (tumor samples T6, T7, and T12) and one more compared to ddPCR (tumor sample T7) in DNA extracted from tumors. For ctDNA from plasma samples, insufficient genetic material prevented the screening of all samples. Still, ARMS-HRMA allowed for scoring more mutations in comparison to SS and 1 more mutation in comparison to ddPCR (plasma sample P7). We propose that ARMS-HRMA might be used as a sensitive, specific, and simple method for the screening of low-level mutations in liquid biopsies, suitable for improving diagnosis and prognosis schemes.

Methylation patterns in dysplasia in inflammatory bowel disease patients.

Background and aims: Inflammatory Bowel Disease (IBD) with colonic involvement increases colorectal cancer risk. However, the distinction between IBD related and sporadic dysplasia in IBD patients is difficult. Some data favors the importance of abnormal DNA methylation in IBD-related carcinogenesis. We aimed to define methylation patterns in patients with colonic cancer or dysplasia diagnosis following an IBD diagnosis.Methods: Multicentric cross-sectional study-91 samples from colonic mucosa with/without dysplasia from 9 patients with IBD-related dysplasia/cancer and 26 patients with IBD and sporadic dysplasia/cancer were included. Methylation patterns of CpG islands in the promoter regions of 67 genes were studied by Methylation-specific Multiplex Ligation-dependent Probe Amplification.Results: Mean age at IBD diagnosis: 42 ± 16 years;at dysplasia diagnosis: 56 ± 14 years. Twenty-ninepatients had ulcerative colitis. Twenty-five patients had at least 1 lesion endoscopically described as adenoma-like, 4 at least 1 non-adenoma like, 3 had cancer and 3 had dysplasia in flat mucosa. No patient had both adenoma-like and non-adenoma-like lesions. Patients with an IBD-related lesion were significantly younger at IBD diagnosis (p = .003) and at dysplasia/cancer diagnosis (p = .039). Promoter methylation of IGF2, RARB, ESR1, CHFR, CDH13, WT1, GATA5, WIF1genes was significantly associated to dysplasia/cancer; methylation of MSH6, TIMP3 was significantly associated to IBD-related dysplasia/cancer. Promoter methylation of MSH6, MSH3, RUNX3, CRABP1, TP73, RARB, CDH13, PAX5, WT1, THBS1, TP53, SFRP1, WIF1, APAF1, BCL2 genes was significantly associated to active IBD.Conclusions: Methylation analysis, namely of MSH6, may contribute to the classification of dysplastic lesions in IBD- to be further tested in prospective studies.

Pediatric Colorectal Cancer: A Heterogenous Entity.

INTRODUCTION: Colorectal cancer (CRC) is extremely rare in pediatric age. A poor outcome has been reported. AIMS: We aimed to characterize a group of pediatric CRC patients. MATERIALS AND METHODS: All patients with CRC below 18 years old registered in our Familial Cancer Risk Clinic (2002-2016) were included. Clinical and histologic features were evaluated. Germline mutations, microsatellite instability, and DNA mismatch repair proteins expression were analyzed. RESULTS: Five patients were included (3 males; mean age at diagnosis: 14.2 years (range, 9 to 17 y) and 4/5 had family history of cancer in second-degree relatives. With a maximum follow-up of 5.6 years, 2/5 patients died after 10 and 24 months, and 1 recurred after 15 months. All tumors were ≥pT3N2 and 3/5 presented signet ring cells/mucinous histology, corresponding to cases with stronger family history of cancer. Nevertheless, all CRCs analyzed (n=4) were microsatellite stable and/or expressed all mismatch repair proteins. Loss of heterozygosity for the 3 Bethesda dinucleotide markers was detected in 1/3 informative CRCs. A likely pathogenic germline MSH2 mutation was identified in only 1 patient. CONCLUSIONS: Pediatric CRC presented advanced disease and poor prognosis. These tumors had distinct histologic and molecular presentations, resembling features from different carcinogenic pathways, thus suggesting a heterogenous nature.

The nonsense mutation MSH2 c.2152C>T shows a founder effect in Portuguese Lynch syndrome families.

The mutational spectrum of the MMR genes is highly heterogeneous, but specific mutations are observed at high frequencies in well-defined populations or ethnic groups, due to founder effects. The MSH2 mutation c.2152C>T, p.(Gln718*), has occasionally been described in Lynch families worldwide, including in Portuguese Lynch syndrome families. During genetic testing for Lynch syndrome at the Portuguese Oncology Institutes of Porto and Lisbon, this mutation was identified in 28 seemingly unrelated families. In order to evaluate if this alteration is a founder mutation, haplotype analysis using microsatellite and SNP markers flanking the MSH2 gene was performed in the 28 probands and 87 family members. Additionally, the geographic origin of these families was evaluated and the age of the mutation estimated. Twelve different haplotypes were phased for 13 out of the 28 families and shared a conserved region of ∼3.6 Mb. Based on the mutation and recombination events observed in the microsatellite haplotypes and assuming a generation time of 25 years, the age estimate for the MSH2 mutation was 273 ± 64 years. The geographic origins of these families were mostly from the Northern region of Portugal. Concluding, these results suggest that the MSH2 c.2152C>T alteration is a founder mutation in Portugal with a relatively recent origin. Furthermore, its high proportion indicates that screening for this mutation as a first step, together with the previously reported Portuguese founder mutations, may be cost-effective in genetic testing of Lynch syndrome suspects of Portuguese ancestry.

Clinical Impact of KRAS and GNAS Analysis Added to CEA and Cytology in Pancreatic Cystic Fluid Obtained by EUS-FNA.

BACKGROUND: Pancreatic cysts are common incidental findings with malignant potential, raising diagnostic and treatment dilemmas. AIMS: To determine the added value of KRAS and GNAS mutation analysis on cyst classification and decision making. METHODS: We analyzed 52 frozen samples of pancreatic cystic fluid obtained by EUS-FNA between 2008 and 2014. In addition to cytology and CEA, mutations of GNAS (exons 8 and 9) and KRAS (exons 2 and 3) genes were analyzed using Sanger sequencing. RESULTS: There were 52 patients, 67% females, with a mean age of 59 ± 15 years (29-91). Cysts were classified as mucinous in 21 patients (40%) (14 low-risk, seven malignant) and non-mucinous in 31 patients (60%). After EUS-FNA, 11 patients had surgery, six had chemotherapy or palliation, one had endoscopic drainage, and 34 are on follow-up after a mean of 57 months. KRAS mutation was detected in nine and GNAS in two samples. Patients harboring cysts with KRAS mutations were older (p = 0.01), cysts were more commonly mucinous (p = 0.001) and malignant (p = 0.01). KRAS mutations were present in both low-risk and malignant mucinous lesions. For identifying mucinous lesions, CEA > 192 ng/mL performed better (AUC ROC = 93%), whereas for malignant/high-risk mucinous lesions, EUS imaging had the best accuracy (AUC ROC = 88%). After molecular analysis, a modification in cyst classification occurred in ten patients, but was correct in only two, a pseudocyst re-classified as IPMN and a malignant cyst as a non-mucinous cyst. CONCLUSIONS: In this cohort of patients with pancreatic cysts, KRAS and GNAS mutations had no significant diagnostic benefit in comparison with conventional testing.

Wnt Signalling-Targeted Therapy in the CMS2 Tumour Subtype: A New Paradigm in CRC Treatment?

Colorectal cancers (CRC) belonging to the consensus molecular subtype 2 (CMS2) have the highest incidence rate, affect mainly the distal colon and rectum, and are characterized by marked Wnt/ß-catenin/Transcription Factor 7-Like 2 (TCF7L2) pathway activation and also by activation of epidermal growth factor receptor (EGFR) signalling. Despite having the highest overall survival, CMS2 tumours are often diagnosed at stage III when an adjuvant chemotherapy-based regimen is recommended. Nevertheless, colorectal cancer stem cells (CSCs) and circulating tumour cells may still evade the current therapeutic options and metastasize, stressing the need to develop more tailored therapeutic strategies. For example, activation of EGFR signalling is being used as a target for tailored therapy, however, therapy resistance is frequently observed. Therefore, targeting the Wnt signalling axis represents an additional therapeutic strategy, considering that CMS2 tumours are "Wnt-addicted". Several efforts have been made to identify Wnt antagonists, either of synthetic or natural origin. However, an inverse gradient of Wnt/ß-catenin/TCF7L2 signalling activity during CRC progression has been suggested, with early stage and metastatic tumours displaying high and low Wnt signalling activities, respectively, which lead us to revisit the "just-right" signalling model. This may pinpoint the use of Wnt signalling agonists instead of antagonists for treatment of metastatic stages, in a context-dependent fashion. Moreover, the poor immunogenicity of these tumours challenges the use of recently emerged immunotherapies. This chapter makes a journey about CMS2 tumour characterization, their conventional treatment, and how modulation of Wnt signalling or immune response may be applied to CRC therapy. It describes the newest findings in this field and indicates where more research is required.

Cesarean sections in Brazil: will they ever stop increasing?

OBJECTIVE: To describe trends, geographic distribution, and risk factors for cesarean deliveries in Brazil in 2000-2011, and to determine if efforts to curtail rates have had a measurable impact. METHODS: This was an observational study using nationwide information from the Department of Informatics of the Unified Health System (DATASUS). Individual level analyses were based on data regarding maternal education, age, parity, and skin color. Ecological analyses at the level of 431 health districts investigated the relationships with health facility density and poverty level. RESULTS: Cesarean rates increased markedly, from 37.9% in 2000 to 53.9% in 2011. Preliminary results from 2012 showed a rate of 55.8%, with the richest geographic areas showing the highest rates. Rates at the municipal level varied from 9%-96%. Cesareans were more common in women with higher education, white skin color, older age, and in primi- paras. In the ecological analyses, the number of health facilities per 1 000 population was strongly and positively correlated with cesarean rates, with an increase of 16.1 percentage points (95% Confidence Interval [95%CI] = 4.3-17.8) for each facility. An increase of 1 percentage point in the poverty rate was associated with a decline of 0.5 percentage point in cesarean rates (95%CI = 0.5-0.6). CONCLUSIONS: The strong associations with maternal education and health facility density suggest that the vast majority of cesareans are not medically indicated. A number of policies and programs have been launched to counteract this trend, but have had virtually no impact.

Needs of older people with intellectual disabilities: variables influencing inter-respondent (client vs staff) agreement.

Background: The importance of understanding the needs of older people with intellectual disabilities (IDs) is obvious, but the research available is limited. This study identifies the self-reported needs of older adults with IDs and compares them with staff reported needs regarding the same older adults with ID, therefore specifying and explaining agreements and disagreements. Method: The needs of 96 older adults with IDs were assessed through the Inventory of Identification of Needs (informant and self-report versions). Results: Both older people with IDs and staff reported quite diverse needs related to all the domains assessed by the IIN: physical health, literacy, information, meaningful activity, participation in the community, mental health, basics needs and accommodation. All the mean scores of the informant version of the IIN were higher than the ones of the self-report version. Agreement amongst informants was influenced by the prominence of needs, the accessibility to and the subjectivity of the information, and social desirability. Conclusions: A consumer-driven approach implies that services should be based on the needs identified.

The Anatomy of the Stomatognathic System in Different Skull Types in Dogs.

The anatomy of the stomatognathic system is important for both clinical evaluations and surgical approaches in all animal species. The aim of this study was to describe the innervation and vascularization of the stomatognathic system of the dog. Twelve dogs without a history of disease or cranial malformation were used: 4 brachycephalic, 4 mesocephalic, and 4 dolichocephalic. The dogs were dissected, and arteries, veins, and nerves related to the masticatory and swallowing components were identified. The distribution pattern of these structures in the 3 different skull types were observed. The entire blood supply of the stomatognathic system is derived from the external carotid artery, which originates from the common carotid artery, and terminates as it branches into the superficial temporal and maxillary arteries. The other main branches of the common carotid artery are the occipital, cranial laryngeal, ascending pharyngeal, lingual, facial, caudal auricular, and parotid arteries. Blood drainage was achieved via the external jugular vein, which originates from the union of the linguofacial and maxillary veins. Brachycephalic dogs had blood vessels with greater sinuosity (more deviations) when compared to dolichocephalic and mesocephalic dogs. The stomatognathic system innervation of brachycephalic skull dogs showed differences in the distribution of the facial nerve in the labial commissure and maxillary and mandibular regions. The cranial conformation of dogs demonstrated anatomical variations of the vascular and neural structures of the stomatognathic system. This data may be useful to improve clinical practice, surgical planning, and interpretation of clinical dysfunctions.

NSCLC presents metabolic heterogeneity, and there is still some leeway for EGF stimuli in EGFR-mutated NSCLC.

BACKGROUND: Metabolic remodeling is crucial in carcinogenesis and cancer progression. Oncogenic mutations may promote metabolic reprogramming in cancer cells to support their energy and biomass requirements. EGFR mutations are commonly found in non-small cell lung cancer (NSCLC) and may induce NSCLC metabolic rewiring. Whether EGFR-driven metabolic reprogramming triggers cell vulnerabilities with therapeutic potential remains unknown. METHODS: The role of EGFR signaling activation by EGF was investigated using NSCLC cell lines with different EGFR and KRAS status: A549 (EGFR WT and KRAS c.34G > A), H292 (EGFR WT and KRAS WT) and PC-9 (EGFR exon 19 E746-A750 deletion and KRAS WT). The effect of EGF on NSCLC cell death and cell cycle was evaluated using flow cytometry, and cell migration was assessed through wound healing. EGFR, HER2, MCT1, and MCT4 expression was analyzed through immunofluorescence or western blotting. We explored the impact of glucose and lactate bioavailability on NSCLC cells' metabolic profile using nuclear magnetic resonance (NMR) spectroscopy. Moreover, the expression of several relevant metabolic genes in NSCLC cells or patient samples was determined by RT-qPCR. RESULTS: We showed that cell lines presented different metabolic profiles, and PC-9 cells were the most responsive to EGF stimulus, as they showed higher rates of cell proliferation and migration, together with altered metabolic behavior. By inhibiting EGFR with gefitinib, a decrease in glucose consumption was observed, which may be related to the fact that despite PC-9 harbor EGFR mutation, they still express the EGFR WT allele. The analysis of NSCLC patients' RNA showed a correlation between MCT1/MCT4 and GLUT1 expression in most cases, indicating that the metabolic information can serve as a reference in patients' follow-up. CONCLUSION: Together, this study shows that NSCLC cell lines have heterogeneous metabolic profiles, which may be underlaid by different genetic profiles, revealing an opportunity to identify and stratify patients who can benefit from metabolism-targeted therapies.

Factor structure and measurement invariance of the BRIEF2 Parent Form across gender in a Portuguese sample.

This study aimed to investigate the factor structure and the measurement invariance across gender of the BRIEF2 Parent Form in Portuguese typically developing children. Participants were 700 typically developing children (n = 352 girls and n = 348 boys) aged 6-16 years. Confirmatory factor analysis was used to test five competing factor models. Consistent with the BRIEF2 original dimensional structure, the three-factor model demonstrated the most adequate fit to the data. The measurement invariance of the three-factor model across gender was supported (configural, metric, and partial scalar invariance). Overall, the BRIEF2 Parent Form showed adequate psychometric properties, suggesting that it is a useful instrument to assess everyday executive functioning based on reports of behaviors observed by parents in healthy Portuguese children.

BRIEF-A: Factor structure and measurement invariance across self-report and informant forms.

OBJECTIVE: This study analyzes the psychometric properties of the two forms (self-report and informant) of the Behavior Rating Inventory of Executive Function-Adult version (BRIEF-A) in a sample of healthy Portuguese adults. METHOD: The participants were 608 adults, 304 of whom answered the self-report form (ages 18-59; 137 male and 167 female) and 304 who answered the informant form (ages 18-70; 110 male and 194 female). RESULTS: The internal consistency for the indexes and the Global Executive Composite was very good (≥.90), whereas for the scales they were either acceptable (between .70 and .80) or good (≥.80), except for the Inhibit scale in both forms. Confirmatory factor analysis was used to test seven competing factor models for each of the forms. The original two-factor model (Behavioral Regulation and Metacognition Indexes) showed a slightly better model fit than the three-factor model (Behavioral Regulation, Emotional Regulation, and Metacognition Indexes) in both forms. The multiple-group analysis of the two-correlated-factor model across forms was supported (configural, metric, and partial scalar invariance). CONCLUSIONS: Overall, the BRIEF-A showed adequate psychometric properties, suggesting that it is a useful instrument to assess everyday executive functioning in healthy Portuguese adults.

H2S-Synthesizing Enzymes Are Putative Determinants in Lung Cancer Management toward Personalized Medicine.

Lung cancer is a lethal disease with no truly efficient therapeutic management despite the progresses, and metabolic profiling can be a way of stratifying patients who may benefit from new therapies. The present study is dedicated to profiling cysteine metabolic pathways in NSCLC cell lines and tumor samples. This was carried out by analyzing hydrogen sulfide (H2S) and ATP levels, examining mRNA and protein expression patterns of cysteine catabolic enzymes and transporters, and conducting metabolomics analysis using nuclear magnetic resonance (NMR) spectroscopy. Selenium-chrysin (SeChry) was tested as a therapeutic alternative with the aim of having an effect on cysteine catabolism and showed promising results. NSCLC cell lines presented different cysteine metabolic patterns, with A549 and H292 presenting a higher reliance on cystathionine ß-synthase (CBS) and cystathionine γ-lyase (CSE) to maintain H2S levels, while the PC-9 cell line presented an adaptive behavior based on the use of mercaptopyruvate sulfurtransferase (MST) and cysteine dioxygenase (CDO1), both contributing to the role of cysteine as a pyruvate source. The analyses of human lung tumor samples corroborated this variability in profiles, meaning that the expression of certain genes may be informative in defining prognosis and new targets. Heterogeneity points out individual profiles, and the identification of new targets among metabolic players is a step forward in cancer management toward personalized medicine.

Frequency of CDH1, CTNNA1 and CTNND1 Germline Variants in Families with Diffuse and Mixed Gastric Cancer.

The most well-characterized hereditary form of gastric cancer is hereditary diffuse gastric cancer (HDGC), an autosomal dominant syndrome characterized by an increased risk of diffuse gastric and lobular breast cancer. HDGC is predominantly caused by germline pathogenic variants in the CDH1 gene, and more rarely in the CTNNA1 gene. Furthermore, the International Gastric Cancer Linkage Consortium (IGCLC) guidelines do not clarify whether or not mixed gastric cancer (with a diffuse component) should be considered in the HDGC genetic testing criteria. We aimed to evaluate the contribution of CTNNA1 and CTNND1 germline variants to HDGC. Additionally, we also intended to compare the frequencies of CDH1 and CTNNA1 (and eventually CTNND1) germline variants between patients with diffuse and mixed gastric carcinomas to evaluate if genetic testing for these genes should or should not be considered in patients with the latter. We analyzed the CDH1 gene in 67 cases affected with early-onset/familial mixed gastric carcinomas and the CTNNA1 and CTNND1 genes in 208 cases with diffuse or mixed gastric cancer who had tested negative for CDH1 pathogenic germline variants. A deleterious CTNNA1 germline variant was found in 0.7% (1/141) of diffuse gastric cancer patients meeting the 2020 IGCLC criteria, as compared to the rate of 2.8% of CDH1 deleterious variants found by us in this setting. No deleterious variants were found in CTNND1, but six variants of uncertain significance were identified in this gene. We did not find any pathogenic CDH1, CTNNA1 or CTNND1 variant in index patients with early-onset/familial mixed gastric cancer, so there is no evidence that supports including this tumor type in the testing criteria for germline variants in these genes. The role of the CTNND1 gene in inherited gastric cancer predisposition is still unclear.

Colorectal cancers choosing sides.

In contrast to the majority of sporadic colorectal cancer which predominantly occur in the distal colon, most mismatch repair deficient tumours arise at the proximal side. At present, these regional preferences have not been explained properly. Recently, we have screened colorectal tumours for mutations in Wnt-related genes focusing specifically on colorectal location. Combining this analysis with published data, we propose a mechanism underlying the side-related preferences of colorectal cancers, based on the specific acquired genetic defects in ß-catenin signalling.

Psychometric properties of the Portuguese version of the Quality of Life Questionnaire (QOL-Q).

BACKGROUND: This study analyzes the psychometric properties of the Portuguese version of the Quality of Life Questionnaire (QOL-Q; Quality of Life Questionnaire Manual - 1993 Manual and 2004 Revision. 2004, IDS Publishing Company, Worthington, OH; Schalock & Keith 2004). METHOD: The analysis of the factorial structure was carried out on a sample of 304 adults with intellectual disabilities, through the use of confirmatory (CFA) and exploratory (EFA) factor analysis. The relationships of the QOL-Q with life satisfaction and self-concept measures were determined in groups composed of respectively 72 and 78 adults with intellectual disabilities. RESULTS: Confirmatory factorial analysis indicated a poor adjustment of the original factor structure to the Portuguese data. EFA indicated the existence of four factors, which include 30 items, and that were also supported by CFA. The total score of the QOL-Q revealed a reduced correlation with life satisfaction, and a moderate correlation with the self-concept. CONCLUSIONS: The Portuguese version of the QOL-Q shows satisfactory psychometric properties, but also some limitations.

Routine Immunohistochemical Analysis of Mismatch Repair Proteins in Colorectal Cancer-A Prospective Analysis.

Recognition of a hereditary colorectal cancer (CRC) syndrome is crucial and Lynch Syndrome (LS) is the most frequent immunohistochemistry (IHC)-screening for mismatch repair proteins (MMR) deficiency in CRC is therefore advocated. An unicentric cohort study was conducted in a central Oncological Hospital to assess its results. All patients under 70 years-old admitted between July 2017-June 2019 and submitted to surgery for CRC were included. Of 275 patients, 56.0% were male, median age 61.0 (IQR:54.5-65.0), with synchronous tumors in six. Histology revealed high grade adenocarcinoma in 8.4%; mucinous and/or signet ring differentiation in 11.3%; and lymphocytic infiltration in 29.8%. Amsterdam (AC) and Bethesda (BC) Criteria were fulfilled in 11 and 74 patients, respectively. IHC revealed loss of expression of MMR proteins in 24 (8.7%), mostly MLH1 and PMS2 (n = 15) and PMS2 (n = 4). Among these, no patients fulfilled AC and 13 fulfilled BC. BRAF mutation or MLH1 promoter hypermethylation was found in four patients with MLH1 loss of expression. Genetic diagnosis was performed in 51 patients, 11 of them with altered IHC. LS was diagnosed in four, and BC was present in three. One patient would not have been diagnosed without routine IHC screening. These results strengthen the important role of IHC screening for MMR proteins loss of expression in CRC.

Colorectal cancers show distinct mutation spectra in members of the canonical WNT signaling pathway according to their anatomical location and type of genetic instability.

It is unclear whether the mutation spectra in WNT genes vary among distinct types of colorectal tumors. We have analyzed mutations in specific WNT genes in a cohort of 52 colorectal tumors and performed a meta-analysis of previous studies. Notably, significant differences were found among the mutation spectra. We have previously shown that in familial adenomatous polyposis, APC somatic mutations are selected to provide the "just-right" level of WNT signaling for tumor formation. Here, we found that APC mutations encompassing at least two beta-catenin down-regulating motifs (20 a.a. repeats) are significantly more frequent in microsatellite unstable (MSI-H) than in microsatellite stable (MSS) tumors where truncations retaining less than two repeats are more frequent (P = 0.0009). Moreover, in cases where both APC hits are detected, selection for mutations retaining a cumulative number of two 20 a.a. repeats became apparent in MSI-H tumors (P = 0.001). This type of mutations were also more frequent in proximal versus distal colonic tumors, regardless of MSI status (P = 0.0008). Among MSI-H tumors, CTNNB1 mutations were significantly more frequent in HNPCC than in sporadic lesions (28% versus 6%, P < 10-6) and were preferentially detected in the proximal colon, independently of MSI status (P = 0.017). In conclusion, the observed spectra of WNT gene mutations in colorectal tumors are likely the result from selection of specific levels of beta-catenin signaling, optimal for tumor formation in the context of specific anatomical locations and forms of genetic instability. We suggest that this may underlie the preferential location of MMR deficient tumors in the proximal colon.

Patient-Derived Explants of Colorectal Cancer: Histopathological and Molecular Analysis of Long-Term Cultures.

Colorectal cancer (CRC) is one of the most common cancers worldwide. Although short-term cultures of tumour sections and xenotransplants have been used to determine drug efficacy, the results frequently fail to confer clinically useful information. Biomarker discovery has changed the paradigm for advanced CRC, though the presence of a biomarker does not necessarily translate into therapeutic success. To improve clinical outcomes, translational models predictive of drug response are needed. We describe a simple method for the fast establishment of CRC patient-derived explant (CRC-PDE) cultures from different carcinogenesis pathways, employing agitation-based platforms. A total of 26 CRC-PDE were established and a subset was evaluated for viability (n = 23), morphology and genetic key alterations (n = 21). CRC-PDE retained partial tumor glandular architecture and microenvironment features were partially lost over 4 weeks of culture. Key proteins (p53 and Mismatch repair) and oncogenic driver mutations of the original tumours were sustained throughout the culture. Drug challenge (n = 5) revealed differential drug response from distinct CRC-PDE cases. These findings suggest an adequate representation of the original tumour and highlight the importance of detailed model characterisation. The preservation of key aspects of the CRC microenvironment and genetics supports CRC-PDE potential applicability in pre- and co-clinical settings, as long as temporal dynamics are considered.

Rapid naming tests: developmental course and relations with neuropsychological measures.

A Digits Rapid Automatized Naming (RAN) test and a Colors and Shapes Rapid Alternating Stimulus (RAS) test were administered to 904 Portuguese, normally achieving children (ages 7 to 15), in order to examine these tests scores developmental course. The results showed that the two tests have slightly different developmental trajectories. In addition, the two tests associations with a large number of neuropsychological measures were determined in three age groups (7-9 years, n = 301; 10-12 years, n = 299; 13-15 years, n = 304). The neuropsychological measures addressed attention/executive functions, motor behavior, verbal memory, visual memory and language. The results indicated that each one of the rapid naming tests brings into play not entirely coincident processes. Although, they converge in terms of their associations with language and attention measures, Colors and Shapes RAS test is more demanding in cognitive and linguistic terms. In addition, while Digits RAN test has little in common with short-term memory, Colors and Shapes RAS test relates moderately with short-term memory, due to the increased demands in terms of effort, access and retrieval of the phonological labels that correspond to the different stimuli categories. The need to differentiate between the two rapid naming tests is supported.