Correlation of molecular data with histopathological and clinical features in a series of 66 patients with medullary thyroid carcinoma.

PURPOSE: Medullary thyroid carcinoma (MTC) displays a wide variety of histopathological features, and several histological variants have been described. In follicular cell-derived thyroid carcinomas, there is a good correlation between genotype and phenotype. In this study, we investigated whether such a correlation is also present in MTC. METHODS: The histopathological features were evaluated in a series of 66 molecularly characterised tumours and correlated with the clinical characteristics. RESULTS: Most MTC exhibited the classical variant (83.3%). Other variants included spindle cell (6.1%), pseudopapillary (4.5%), paraganglioma-like (3.0%), angiosarcoma-like (1.5%), and oncocytic follicular (1.5%). Tumours were classified into four groups: group 1, with somatic p.Met918Thr and p.Ala883Phe RET mutations; group 2, with other RET mutations; group 3, with RAS mutations; and group 4, without RET or RAS mutations. Tumours from groups 1 and 4 were typically associated with the classical variant, with abundant fibrosis, lymphovascular invasion, extrathyroidal extension, and more advanced stages of disease, whereas group 2 included histological variants other than the classical variant (namely, pseudopapillary and paraganglioma-like), with tumours that were highly cellular, less invasive, and with a better overall prognosis. In tumours from group 4, amyloid deposition was characteristically absent or low. The spindle cell variant appeared only in tumours from group 3, which had high cellularity and a degree of invasion and prognosis intermediate between groups 1 and 2, but better than group 4. The grade of fibrosis correlated directly with the clinical outcome. CONCLUSION: Our results support the idea that a genotype-phenotype correlation does, indeed, exist in MTC. However, further studies are warranted to confirm these findings in a larger sample size.

The role of EIF1AX in thyroid cancer tumourigenesis and progression.

PURPOSE: The EIF1AX gene was recently described as a new thyroid cancer-related gene. Its mutations were mainly reported in poorly differentiated (PDTC) and anaplastic thyroid cancers (ATC), but also in well-differentiated thyroid cancer (WDTC) and in benign thyroid lesions, although less frequently. Our aim was to address whether EIF1AX mutations are present in the different stages of thyroid tumourigenesis (from hyperplasia to well-differentiated and to poorly differentiated/undifferentiated lesions), and to clarify its role in this process. METHODS: We analysed the EIF1AX gene in a series of 16 PDTC and ATC cases with coexistent well-differentiated regions and/or benign lesions. In EIF1AX mutant cases we also assessed the presence of RAS genes mutations. RESULTS: We identified the mutation p.Ala113_splice in the EIF1AX gene in two PDTCs (neither present in the well-differentiated counterparts nor in the benign areas). One of these tumours also evidenced the mutation p.Glu61Arg in NRAS in both poorly and well-differentiated regions, further suggesting that the EIF1AX p.Ala113_splice mutation could be associated with tumoural progression. In another patient we did not find any EIF1AX alteration in the PDTC component, but we detected the EIF1AX p.Gly6_splice mutation in the PTC area (both regions were RAS wild-type). This mutation did not seem to be related with dedifferentiation. CONCLUSIONS: According to our results, distinct mutations on EIF1AX may be related to different phenotypes/behaviours. Despite being a small series, which reflects the difficulty in retrieving PDTC and ATC surgical samples with well-differentiated and/or benign areas, our study may provide new insights into thyroid cancer tumourigenesis and dedifferentiation.

The efficacy of HRAS and CDK4/6 inhibitors in anaplastic thyroid cancer cell lines.

PURPOSE: Anaplastic thyroid carcinomas (ATCs) are non-responsive to multimodal therapy, representing one of the major challenges in thyroid cancer. Previously, our group has shown that genes involved in cell cycle are deregulated in ATCs, and the most common mutations in these tumours occurred in cell proliferation and cell cycle related genes, namely TP53, RAS, CDKN2A and CDKN2B, making these genes potential targets for ATCs treatment. Here, we investigated the inhibition of HRAS by tipifarnib (TIP) and cyclin D-cyclin-dependent kinase 4/6 (CDK4/6) by palbociclib (PD), in ATC cells. METHODS: ATC cell lines, mutated or wild type for HRAS, CDKN2A and CDKN2B genes, were used and the cytotoxic effects of PD and TIP in each cell line were evaluated. Half maximal inhibitory concentration (IC50) values were determined for these drugs and its effects on cell cycle, cell death and cell proliferation were subsequently analysed. RESULTS: Cell culture studies demonstrated that 0.1 µM TIP induced cell cycle arrest in the G2/M phase (50%, p < 0.01), cell death, and inhibition of cell viability (p < 0.001), only in the HRAS mutated cell line. PD lowest concentration (0.1 µM) increased significantly cell cycle arrest in the G0/G1 phase (80%, p < 0.05), but only in ATC cell lines with alterations in CDKN2A/CDKN2B genes; additionally, 0.5 µM PD induced cell death. The inhibition of cell viability by PD was more pronounced in cells with alterations in CDKN2A/CDKN2B genes (p < 0.05) and/or cyclin D1 overexpression. CONCLUSIONS: This study suggests that TIP and PD, which are currently in clinical trials for other types of cancer, may play a relevant role in ATC treatment, depending on the specific tumour molecular profile.

Correlation of RET somatic mutations with clinicopathological features in sporadic medullary thyroid carcinomas.

Screening of REarranged during Transfection (RET) gene mutations has been carried out in different series of sporadic medullary thyroid carcinomas (MTC). RET-positive tumours seem to be associated to a worse clinical outcome. However, the correlation between the type of RET mutation and the patients' clinicopathological data has not been evaluated yet. We analysed RET exons 5, 8, 10-16 in fifty-one sporadic MTC, and found somatic mutations in thirty-three (64.7%) tumours. Among the RET-positive cases, exon 16 was the most frequently affected (60.6%). Two novel somatic mutations (Cys630Gly, c.1881del18) were identified. MTC patients were divided into three groups: group 1, with mutations in RET exons 15 and 16; group 2, with other RET mutations; group 3, having no RET mutations. Group 1 had higher prevalence (P=0.0051) and number of lymph node metastases (P=0.0017), and presented more often multifocal tumours (P=0.037) and persistent disease at last control (P=0.0242) than group 2. Detectable serum calcitonin levels at last screening (P=0.0119) and stage IV disease (P=0.0145) were more frequent in group 1, than in the other groups. Our results suggest that, among the sporadic MTC, cases with RET mutations in exons 15 and 16 are associated with the worst prognosis. Cases with other RET mutations have the most indolent course, and those with no RET mutations have an intermediate risk.

Identification and characterization of two novel germline RET variants associated with medullary thyroid carcinoma.

Activating germline mutations in the RET proto-oncogene are responsible for about 98 % of the familial forms of medullary thyroid carcinoma (MTC), which represent 25 % of all MTC cases. The search for germline mutations in this gene is important for the recognition of hereditary forms of MTC and further identification of at-risk relatives who may benefit from early clinical intervention. Genotype-phenotype correlations are well established for most disease-causing RET mutations, allowing risk stratification. The association of a new RET variant with the MTC phenotype and familial predisposition requires the assessment of its functional and clinical significance. The aim of this study was to evaluate the oncogenic potential of two newly identified RET germline variants associated with late-onset MTC. In vitro functional assays were designed to address the transforming potential of novel RET variants, through their expression in non-transformed cells, and comparing their effect with wild-type RET. The new variants were identified in codons 515 (p.C515W) and 636 (p.T636M) located, respectively, in exons 8 and 11, thus resulting in amino acid substitutions in the extracellular region of the tyrosine kinase receptor RET. Through functional assays, we observed increased cell growth and proliferation, loss of contact inhibition, and a stimulation of cell migration, suggesting that these new RET variants hold some relevant transforming potential. The transforming potential of these novel RET variants was of low-grade, when compared to that of RET MEN2A-causing mutation p.C634R, probably explaining the mild phenotype characterized by late onset and low clinical aggressiveness.

STFT or CWT for the detection of Doppler ultrasound embolic signals.

Aiming reliable detection and localization of cerebral blood flow and emboli, embolic signals were added to simulated middle cerebral artery Doppler signals and analysed. Short-time Fourier transform (STFT) and continuous wavelet transform (CWT) were used in the evaluation. The following parameters were used in this study: the powers of the embolic signals added were 5, 6, 6.5, 7, 7.5, 8 and 9 dB; the mother wavelets for CWT analysis were Morlet, Mexican hat, Meyer, Gaussian (order 4) and Daubechies (orders 4 and 8); and the thresholds for detection (equated in terms of false positive, false negative and sensitivity) were 2 and 3.5 dB for the CWT and STFT, respectively. The results indicate that although the STFT allows accurately detecting emboli, better time localization can be achieved with the CWT. Among the CWT, the current best overall results were obtained with Mexican Hat mother wavelet, with optimal results for sensitivity (100% detection rate) for nearly all emboli power values studied.

The inheritance of factors associated with joint mobility.

From a sample of 1,500 individuals belonging to 442 migrant nuclear families from northeastern Brazil, information on the interphalangial mobility was obtained: (a) the grades of extension of both the right and left thumbs and (b) the angle (in degrees) formed by the distant and proximal phalanx of the thumb. The first principal component of these variables was estimated and called "extensibility." A negative association of extensibility and age, as well as with inbreeding, was detected. Complex segregation analysis was applied to extensibility and both a multigenic mechanism and an extra transmissible component were detected. Mendelian inheritance was rejected, while a model with multifactorial inheritance, together with a factor that is inherited with a transmission probability different from 1/2 (tau = 0.63), was not rejected. These findings were supported by path analysis, which showed an important biologic inheritance (h2 = 0.675) and the existence of a small but significant cultural component (c2 = 0.003). The observed "inbreeding" effect, therefore, could not be attributed to a genetic mechanism and probably is the effect of concomitant environmental variability.

The association of genetic markers and malaria infection in the Brazilian Western Amazonian region.

Almost all individuals (182) belonging to an Amazonian riverine population (Portuchuelo, RO, Brazil) were investigated for ascertaining data on epidemiological aspects of malaria. Thirteen genetic blood polymorphisms were investigated (ABO, MNSs, Rh, Kell, and Duffy systems, haptoglobins, hemoglobins, and the enzymes glucose-6-phosphate dehydrogenase, glyoxalase, phosphoglucomutase, carbonic anhydrase, red cell acid phosphatase, and esterase D). The results indicated that the Duffy system is associated with susceptibility to malaria, as observed in other endemic areas. Moreover, suggestions also arose indicating that the EsD and Rh loci may be significantly associated with resistance to malaria. If statistical type II errors and sample stratification could be ruled out, hypotheses on the existence of a causal mechanism or an unknown closely linked locus involved in susceptibility to malaria infection may explain the present findings.

Ethnic admixture composition of two western Amazonian populations.

A small riverine community, Portuchuelo (8 degrees 37'S, 63 degrees 49'W), and a rural county, Monte Negro (10 degrees 15'S, 63 degrees 18'W), both in the state of Rondjnia, Brazil, were studied for the purposes of ascertaining health conditions and the causes of the variability of some infectious diseases. The sample included 181 inhabitants of Portuchuelo and 924 of Monte Negro. Data on 11 blood polymorphisms (ABO, Rh, MNSs, Kell, Fy, haptoglobin, hemoglobin, ACP1, PGM1, GLO1, and CA2) were used to determine the ethnic composition of the inhabitants of Portuchuelo and Monte Negro. The contributions of Africans, Amerindians, and Europeans to the ethnic composition of the studied populations were, respectively, 0.21 +/- 0.046, 0.44 +/- 0.064, and 0.35 +/- 0.069 in Portuchuelo; and 0.25 +/- 0.032,0.12 +/- 0.046, and 0.63 +/- 0.054 in Monte Negro.

A rural community in a Brazilian Western Amazonian Region: some demographic and epidemiological patterns.

Some demographic and epidemiological patterns of the rural population of Monte Negro, locality situated in the State of Rondônia (Brazil), Western Amazonia, are described based on a sample of 924 randomly selected individuals, approximately 10% of the whole population. The main features of this sample are (1) the illiteracy rates in the parental generation were 23% for fathers and 20% for mothers. Among children, this figure dropped to 6%; (2) housing in Monte Negro is characterized by being constructed with wood (92%), and also a floor (75%). Nevertheless, only 32% of these houses had electric energy; (3) the mean ages for the parental generation were 41.9 for males and 36.3 for females. These values for the offspring generation were 12.2 and 10.5, respectively; (4) the sex-ratio of the offspring generation was 1.32;(5) the bioassay of kinship was estimated as.033 for this long range migrant population; (6) the prevalence of some macrophage dependent infectious disease was conspicuously high; (7) the reported number of malarial episodes among males and females was statistically different, suggesting that malaria may be, in part, a "professional" disease; (8) the prevalence of serum-positive reactions against B-hepatitis is distressing. It has a strong age dependence and reaches 74% among adult males. Conversely, signs of active infection (AgHbs) rises to 16% among children.

Multistrange baryon production in Au-Au collisions at sqrt[s(NN)]=130 GeV.

The transverse mass spectra and midrapidity yields for Xis and Omegas are presented. For the 10% most central collisions, the (-)Xi(+)/h(-) ratio increases from the Super Proton Synchrotron to the Relativistic Heavy Ion Collider energies while the Xi(-)/h(-) stays approximately constant. A hydrodynamically inspired model fit to the Xi spectra, which assumes a thermalized source, seems to indicate that these multistrange particles experience a significant transverse flow effect, but are emitted when the system is hotter and the flow is smaller than values obtained from a combined fit to pi, K, p, and Lambdas.

A rural community in a Brazilian Western Amazonian region: some demographic and epidemiological patterns

Some demographic and epidemiological patterns of the rural population of Monte Negro, locality situated in the State of Rondônia (Brazil), Western Amazonia, are described based on a sample of 924 randomly selected individuals, approximately 10 percent of the whole population. The main features of this sample are (1) the illiteracy rates in the parental generation were 23 percent for fathers and 20 percent for mothers. Among children, this figure dropped to 6 percent; (2) housing in Monte Negro is characterized by being constructed with wood (92 percent), and also a floor (75 percent). Nevertheless, only 32 percent of these houses had electric energy; (3) the mean ages for the parental generation were 41.9 for males and 36.3 for females. These values for the offspring generation were 12.2 and 10.5, respectively; (4) the sex-ratio of the offspring generation was 1.32;(5) the bioassay of kinship was estimated as .033 for this long range migrant population; (6) the prevalence of some macrophage dependent infectious disease was conspicuously high; (7) the reported number of malarial episodes among males and females was statistically different, suggesting that malaria may be, in part, a "professional" disease; (8) the prevalence of serum-positive reactions against B-hepatitis is distressing. It has a strong age dependence and reaches 74 percent among adult males. Conversely, signs of active infection (AgHbs) rises to 16 percent among children

The association of genetic markers and malaria infection in the Brazilian Western Amazonian region

Almost all individuals (182) belonging to an Amazonian riverine population (Portuchuelo, RO, Brazil) were investigated for ascertaining data on epidemiological aspects of malaria. Thirteen genetic blood polymorphisms were investigated (ABO, MNSs, Rh, Kell, and Duffy systems, haptoglobins, hemoglobins, and the enzymes glucose-6-phosphate dehydrogenase, glyoxalase, phosphoglucomutase, carbonic anhydrase, red cell acid phosphatase, and esterase D). The results indicated that the Duffy system is associated with susceptibility to malaria, as observed in other endemic areas. Moreover, suggestions also arose indicating that the EsD and Rh loci may be significantly associated with resistance to malaria. If statistical type II errors and sample stratification could be ruled out, hypotheses on the existence of a causal mechanism or an unknown closely linked locus involved in susceptibility to malaria infection may explain the present findings