CD133 Expression in Medullary Thyroid Cancer Cells Identifies Patients with Poor Prognosis.

CONTEXT: The identification of markers able to determine medullary thyroid cancer (MTC) patients at high-risk of disease progression is critical to improve their clinical management and outcome. Previous studies have suggested that expression of the stem cell marker CD133 is associated with MTC aggressiveness. OBJECTIVE: To evaluate CD133 impact on disease progression in MTC and explore the regulatory mechanisms leading to the upregulation of this protein in aggressive tumors. PATIENTS: We compiled a series of 74 MTCs with associated clinical data and characterized them for mutations in RET and RAS proto-oncogenes, presumed to be related with disease clinical behavior. RESULTS: We found that CD133 immunohistochemical expression was associated with adverse clinicopathological features and predicted a reduction in time to disease progression even when only RET-mutated cases were considered in the analysis (log-rank test P < 0.003). Univariate analysis for progression-free survival revealed CD133 expression and presence of tumor emboli in peritumoral blood vessels as the most significant prognostic covariates among others such as age, gender, and prognostic stage. Multivariate analysis identified both variables as independent factors of poor prognosis (hazard ratio = 16.6 and 2; P = 0.001 and 0.010, respectively). Finally, we defined hsa-miR-30a-5p, a miRNA downregulated in aggressive MTCs, as a CD133 expression regulator. Ectopic expression of hsa-miR-30a-5p in MZ-CRC-1 (RETM918T) cells significantly reduced CD133 mRNA expression. CONCLUSIONS: Our results suggest that CD133 expression may be a useful tool to identify MTC patients with poor prognosis, who may benefit from a more extensive primary surgical management and follow-up.

Doenças pulmonares interticiais: linfangioliomiomatose em questão / Intertitial pulmonary diseases: lymphangioleiomyomatosis in question

As doenças pulmonares intersticiais (DPIs) são conceituadas como distúrbios que acometem o parênquima pulmonar - o endotélio cailar, os alvéolos, o epitélio alveolar e os espaços entreestas estruturas, bem como os tecidos perivasculares e linfáticos - , podendo ser classificadas segundo critérios histopatológicos, distinguindo-se dois grandes grupos: 1. das associadas à inflamação e fibrose; e 2. daquelas com reação granulomatosa predominante na área intersticial u vasculas. A linfangioliomiomatose (LAM) é uma rara DPI, idiópática, e com altas taxas de morbimortalidade, sendo caracterizada por uma multiplicação acelerada de células musculares lisas imaturas em qualquer estrutura pulmonar. No presente artigo apresentar-se-á uma revisão da literatura enfocando a etiopatogenia, a epidemiologia, o quadro clínico, o diagnóstico - procedimentos, critérios e diagnóstico diferencial - o tratamento e o prognóstico da LAM.

The interstitial pulmonary diseases (IPDs) are a range of disorders that affect the pulmonary parenchyma - the capillary endothelium, alveoli, alveolar epithelium and the spaces between thesestructures, as well as the perivascular and lymphatic tissues. The IPDs may be classified according to histopathologic criteria, and are divided into two large groups: 1. those associated with inflammation and fibrosis; and 2. those associated with granulomatous reactions predominantly in the interstitial or vascular area. Lymphangioleiomyomatosis (LAM) ia a rare, idiopathic IPD with high morbimortality rates, which is characterized by an accelerated multiplication of immature smooth muscle cellsin any pulmonary structure. In this article, we present a review of the literature onthe etiopathogenesis, epidemiology, clinical picture, diagnosis and differential diagnosos, treatment, and prognosis of this condition.