Search Results Heading

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
Title added to your shelf!
View what I already have on My Shelf.
Oops! Something went wrong.
Oops! Something went wrong.
While trying to add the title to your shelf something went wrong :( Kindly try again later!
Are you sure you want to remove the book from the shelf?
Oops! Something went wrong.
Oops! Something went wrong.
While trying to remove the title from your shelf something went wrong :( Kindly try again later!
    Done
    Filters
    Reset
  • Discipline
      Discipline
      Clear All
      Discipline
  • Is Peer Reviewed
      Is Peer Reviewed
      Clear All
      Is Peer Reviewed
  • Item Type
      Item Type
      Clear All
      Item Type
  • Subject
      Subject
      Clear All
      Subject
  • Year
      Year
      Clear All
      From:
      -
      To:
  • More Filters
150 result(s) for "Kebebew, Electron"
Sort by:
Adrenal Incidentaloma
An adrenal mass discovered in testing for another condition (an “incidentaloma”) warrants biochemical tests to detect pheochromocytoma, excess cortisol, and, in a patient with hypertension, primary hyperaldosteronism. Imaging may distinguish benign from malignant lesions. Small nonfunctioning adrenal tumors with low CT attenuation generally do not warrant intervention or long-term follow-up.
MiR-20a Is Upregulated in Anaplastic Thyroid Cancer and Targets LIMK1
There have been conflicting reports regarding the function of miR-20a in a variety of cancer types and we previously found it to be dysregulated in sporadic versus familial papillary thyroid cancer. In this study, we studied the expression of miR-20a in normal, benign and malignant thyroid samples, and its effect on thyroid cancer cells in vitro and in vivo. The expression of miR-20a in normal, benign and malignant thyroid tissue was determined by quantitative RT-PCR. Thyroid cancer cells were transfected with miR-20a and the effect on cellular proliferation, tumor spheroid formation, and invasion was evaluated. Target genes of miR-20 were determined by genome-wide mRNA expression analysis with miR-20a overexpression in thyroid cancer cells and target prediction database. Target genes were validated by quantitative PCR and immunoblotting, and luciferase assays. MiR-20a expression was significantly higher in anaplastic thyroid cancer than in differentiated thyroid cancer, and benign and normal thyroid tissues. MiR-20a significantly inhibited thyroid cancer cell proliferation in vitro (p<0.01) and in vivo (p<0.01), tumor spheroid formation (p<0.05) and invasion (p<0.05) in multiple thyroid cancer cell lines. We found that LIMK1 was a target of miR-20a in thyroid cancer cell lines and direct knockdown of LIMK1 recapitulated the effect of miR-20a in thyroid cancer cells. To our knowledge, this is the first study to demonstrate that miR-20a plays a role as a tumor suppressor in thyroid cancer cells and targets LIMK1. Our findings suggest the upregulated expression of miR-20a in anaplastic thyroid cancer counteracts thyroid cancer progression and may have therapeutic potential.
Metastatic adrenocortical carcinoma displays higher mutation rate and tumor heterogeneity than primary tumors
Adrenocortical cancer (ACC) is a rare cancer with poor prognosis and high mortality due to metastatic disease. All reported genetic alterations have been in primary ACC, and it is unknown if there is molecular heterogeneity in ACC. Here, we report the genetic changes associated with metastatic ACC compared to primary ACCs and tumor heterogeneity. We performed whole-exome sequencing of 33 metastatic tumors. The overall mutation rate (per megabase) in metastatic tumors was 2.8-fold higher than primary ACC tumor samples. We found tumor heterogeneity among different metastatic sites in ACC and discovered recurrent mutations in several novel genes. We observed 37–57% overlap in genes that are mutated among different metastatic sites within the same patient. We also identified new therapeutic targets in recurrent and metastatic ACC not previously described in primary ACCs. Adrenocortical cancer (ACC) is a rarely diagnosed and aggressive cancer whose metastatic form has been scarcely studied. Here, the authors study primary and metastatic ACC to investigate genomic heterogeneity, discovering higher mutation rates in metastatic lesions and novel recurrent mutations.
Somatic HIF2A Gain-of-Function Mutations in Paraganglioma with Polycythemia
Two patients with paraganglioma (one of whom also had somatostatinoma) were found to have mutations in HIF2A that altered HIF-2α turnover and led to excess erythropoietin production and polycythemia. Hypoxia-inducible factors, originally described by Wang et al., 1 are transcription factors that respond to changes in tissue oxygen concentration. These highly conserved proteins are composed of α and β subunits. The HIF-β subunit is constitutively expressed, whereas the α subunits are inducible by hypoxia and are associated with aggressive, treatment-refractory tumors. 2 , 3 Under normoxic conditions, HIF-1α, HIF-2α, and HIF-3α are hydroxylated on specific prolyl residues, allowing for recognition by the von Hippel–Lindau (VHL) tumor-suppressor protein, ubiquitination, and rapid degradation through the proteasome. 4 Under hypoxic conditions, prolyl hydroxylation of HIF-α proteins is reduced, resulting in their stabilization and, in turn, transcription . . .
Germline HABP2 Mutation Causing Familial Nonmedullary Thyroid Cancer
A kindred has been identified with a mutation in HABP2 that has a dominant-negative function and causes nonmedullary thyroid cancer in heterozygotes. Thyroid cancer is common in the United States, with more than 62,000 cases projected in 2015. Thyroid cancers of follicular-cell origin account for more than 95% of all cases of thyroid cancer, with the remaining cancers originating from parafollicular cells (medullary thyroid cancer). Familial nonmedullary thyroid cancer, which accounts for 3 to 9% of all cases of thyroid cancer, has an autosomal dominant pattern of inheritance. 1 , 2 It may be syndromic, occurring as a component of one of the familial cancer syndromes (familial adenomatous polyposis, Gardner’s syndrome, Cowden’s disease, Carney complex type 1, Werner’s syndrome, and the DICER1 syndrome) for . . .
Anaplastic thyroid cancer spheroids as preclinical models to test therapeutics
Anaplastic thyroid cancer (ATC) is the most aggressive thyroid cancer. Despite advances in tissue culture techniques, a robust model for ATC spheroid culture is yet to be developed. In this study, we created an efficient and cost-effective 3D tumor spheroids culture system from human ATC cells and existing cell lines that better mimic patient tumors and that can enhance our understanding of in vivo treatment response. We found that patient-derived ATC cells and cell lines can readily form spheroids in culture with a unique morphology, size, and cytoskeletal organization. We observed both cohesive (dense and solid structures) and discohesive (irregularly shaped structures) spheroids within the same culture condition across different cell lines. BRAF WT ATC spheroids grew in a cohesive pattern, while BRAF V600E -mutant ATC spheroids had a discohesive organization. In the patient-derived BRAF V600E -mutant ATC spheroids, we observed both growth patterns, but mostly the discohesive type. Histologically, ATC spheroids had a similar morphology to the patient’s tumor through H&E staining and proliferation marker staining. Moreover, RNA sequencing analysis revealed that the gene expression profile of tumor cells derived from the spheroids closely matched parental patient tumor-derived cells in comparison to monolayer cultures. In addition, treatment response to combined BRAF and MEK inhibition in BRAF V600E -mutant ATC spheroids exhibited a similar sensitivity to the patient clinical response. Our study provides a robust and novel ex vivo spheroid model system that can be used in both established ATC cell lines and patient-derived tumor samples to better understand the biology of ATC and to test therapeutics.
Localization of Insulinoma Using 68Ga-DOTATATE PET/CT Scan
Précis:We studied 68Ga-DOTATATE PET/CT imaging in patients with insulinoma and found it identifies most tumors and should be considered as an adjunct imaging study.AbstractContext:Reliable localization of insulinoma is critical for successful treatment.Objective:This study compared the accuracy of 68Gallium DOTA-(Tyr3)-octreotate (Ga-DOTATATE) positron emission tomography (PET)/computed tomography (CT) to anatomic imaging modalities, selective arterial secretagogue injection (SASI), and intraoperative ultrasound (IO ultrasound) and palpation for localizing insulinoma in patients who were biochemically cured.Design, Setting, and Patients:We conducted a retrospective analysis of 31 patients who had an insulinoma. The results of CT, magnetic resonance imaging (MRI), ultrasound, IO ultrasound, 68Ga-DOTATATE PET/CT, SASI, and operative findings were analyzed.Intervention, Main Outcome Measures, and Results:The insulinomas were correctly localized in 17 out of 31 (55%) patients by CT, in 17 out of 28 (61%) by MRI, in 6 out of 28 (21%) by ultrasound, and in 9 out of 10 (90%) by 68Ga-DOTATATE. In 29 of 31 patients (93.5%) who had IO ultrasound, an insulinoma was successfully localized. Thirty patients underwent SASI, and the insulinoma was regionalized in 28 out of 30 patients (93%). In 19 out of 23 patients (83%), manual palpation identified insulinoma. In patients who had all 4 noninvasive imaging studies, CT was concordant with 68Ga-DOTATATE in 6 out of 9 patients (67%), MRI in 8 out of 9 (78%), ultrasound in 0 out of 9; the lesion was only seen by 68Ga-DOTATATE in 1 out of 9 (11%).Conclusions 68Ga-DOTATATE PET/CT identifies most insulinomas and may be considered as an adjunct imaging study when all imaging studies are negative and when a minimally invasive surgical approach is planned.
miR-126-3p Inhibits Thyroid Cancer Cell Growth and Metastasis, and Is Associated with Aggressive Thyroid Cancer
Previous studies have shown that microRNAs are dysregulated in thyroid cancer and play important roles in the post-transcriptional regulation of target oncogenes and/or tumor suppressor genes. We studied the function of miR-126-3p in thyroid cancer cells, and as a marker of disease aggressiveness. We found that miR-126-3p expression was significantly lower in larger tumors, in tumor samples with extrathyroidal invasion, and in higher risk group thyroid cancer in 496 papillary thyroid cancer samples from The Cancer Genome Atlas study cohort. In an independent sample set, lower miR-126-3p expression was observed in follicular thyroid cancers (which have capsular and angioinvasion) as compared to follicular adenomas. Mechanistically, ectopic overexpression of miR-126-3p significantly inhibited thyroid cancer cell proliferation, in vitro (p<0.01) and in vivo (p<0.01), colony formation (p<0.01), tumor spheroid formation (p<0.05), cellular migration (p<0.05), VEGF secretion and endothelial tube formation, and lung metastasis in vivo. We found 14 predicted target genes, which were significantly altered upon miR-126-3p transfection in thyroid cancer cells, and which are involved in cancer biology. Of these 14 genes, SLC7A5 and ADAM9 were confirmed to be inhibited by miR-126-3p overexpression and to be direct targets of miR-136-3p. To our knowledge, this is the first study to demonstrate that miR-126-3p has a tumor-suppressive function in thyroid cancer cells, and is associated with aggressive disease phenotype.
A phase 1 study of nevanimibe HCl, a novel adrenal-specific sterol O-acyltransferase 1 (SOAT1) inhibitor, in adrenocortical carcinoma
SummaryBackground Adrenocortical carcinoma (ACC) is a rare and aggressive malignancy with very limited treatment options. Nevanimibe HCl (formerly ATR-101), a novel adrenal-specific sterol O-acyltransferase 1 (SOAT1) inhibitor, has been shown in nonclinical studies to decrease adrenal steroidogenesis at lower doses and to cause apoptosis of adrenocortical cells at higher doses. Methods This phase 1, multicenter, open-label study assessed the safety and pharmacokinetics (PK) of nevanimibe in adults with metastatic ACC (NCT01898715). A “3 + 3” dose-escalation design was used. Adverse events (AEs), PK, and tumor response based on Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 were evaluated every 2 months. Results 63 patients with metastatic ACC, all of whom had previously failed systemic chemotherapy and only 2 of whom were mitotane-naïve, were dosed with oral nevanimibe at doses ranging from 1.6 mg/kg/day to 158.5 mg/kg/day. Subjects who did not experience tumor progression or a dose-limiting toxicity (DLT) could continue to receive additional cycles. No patients experienced a complete or partial response; however, 13 of the 48 (27%) patients who underwent imaging at 2 months had stable disease (SD), and 4 of these had SD > 4 months. In addition, drug-related adrenal insufficiency, considered a pharmacologic effect of nevanimibe, was observed in two patients. The most common treatment-emergent AEs were gastrointestinal disorders (76%), including diarrhea (44%) and vomiting (35%). A maximum tolerated dose (MTD) could not be defined, as very few dose-limiting toxicities (DLTs) occurred. Because the large number of tablets required at the highest dose (i.e., ~24 tablets/day) resulted in low-grade gastrointestinal adverse effects, a maximum feasible dose of 128.2 mg/kg/day was established as a dose that could be taken on a long-term basis. Conclusions This study demonstrated the safety of nevanimibe at doses of up to ~6000 mg BID. As the total number of tablets required to achieve an MTD exceeded practical administration limits, a maximum feasible dose was defined. Given that the expected exposure levels necessary for an apoptotic effect could not be achieved, the current formulation of nevanimibe had limited efficacy in patients with advanced ACC.