Pan-Genomic Sequencing Reveals Actionable CDKN2A/2B Deletions and Kataegis in Anaplastic Thyroid Carcinoma

Anaplastic thyroid carcinoma (ATC) is a lethal malignancy characterized by poor response to conventional therapies. Whole-genome sequencing (WGS) analyses of this tumor type are limited, and we therefore interrogated eight ATCs using WGS and RNA sequencing. Five out of eight cases (63%) displayed cyclin-dependent kinase inhibitor 2A (CDKN2A) abnormalities, either copy number loss (n = 4) or truncating mutations (n = 1). All four cases with loss of the CDKN2A locus (encoding p16 and p14arf) also exhibited loss of the neighboring CDKN2B gene (encoding p15ink4b), and displayed reduced CDKN2A/2B mRNA levels. Mutations in established ATC-related genes were observed, including TP53, BRAF, ARID1A, and RB1, and overrepresentation of mutations were also noted in 13 additional cancer genes. One of the more predominant mutational signatures was intimately coupled to the activity of Apolipoprotein B mRNA-editing enzyme, the catalytic polypeptide-like (APOBEC) family of cytidine deaminases implied in kataegis, a focal hypermutation phenotype, which was observed in 4/8 (50%) cases. We corroborate the roles of CDKN2A/2B in ATC development and identify kataegis as a recurrent phenomenon. Our findings pinpoint clinically relevant alterations, which may indicate response to CDK inhibitors, and focal hypermutational phenotypes that may be coupled to improved responses using immune checkpoint inhibitors.

Carcinoma Showing Thymus-like Differentiation (CASTLE) with Synchronous Papillary Thyroid Carcinoma: A Case Report and Review

Carcinoma showing thymus-like differentiation (CASTLE) is a rare malignant tumor that accounts for 0.1%–0.15% of all thyroid cancers. More than half of the patients have tumor extension to adjacent organs, including the recurrent laryngeal nerve, trachea, and esophagus. The diagnosis of CASTLE is based on histology and immunohistochemistry. A 58-year-old female patient complained of hoarseness for one and half years. Right side vocal cord palsy was diagnosed by fiberscopy. Thyroid sonography revealed right thyroid tumors, which were reported to be papillary thyroid carcinoma through FNAC. Total thyroidectomy with central lymph node dissection was performed. Pathologist found 2 isolated malignancy tumors. One patient in the right thyroid lobe had papillary thyroid carcinoma features. The other extrathyroid tumor seemed to be separated from the first tumor and invaded the thyroid capsule. After multiple immunohistochemical studies, PTC synchronous CASTLE was the final diagnosis. Coexisting PTC and CASTLE is very rare. This is the first report to describe a case showing PTC at first, while subsequent pathologic examination revealed the presence of CASTLE in addition to PTC. Since the prognosis of CASTLE is favorable, the treatment is different from other aggressive thyroid cancers, such as poorly differentiated or anaplastic thyroid carcinoma.

Roles of reactive oxygen species, mitochondrial membrane potential, and p53 in evodiamine-induced apoptosis and G2/M arrest of human anaplastic thyroid carcinoma cells

Background Our previous studies have shown that evodiamine (EVO) as paclitaxel and nocodazole could trigger apoptosis in various human cancer cells including human renal cell carcinoma cells, colorectal carcinoma cells, and glioblastoma cells. This study aims to investigate the anti-cancer effects of EVO on human anaplastic thyroid carcinoma (ATC) cells, and underlining mechanism. Methods Two different endogenous p53 status human anaplastic thyroid carcinoma (ATC) cells including SW1736 (wtp53) and KAT4B (mutp53) were applied in the present study. The cytotoxicity of EVO on ATC cells was measured by MTT assay, and apoptosis and G2/M arrest were detected by propidium iodide (PI) staining followed by flow cytometry. Expression of indicated proteins was evaluated by Western blotting analysis, and pharmacological studies using chemical inhibitors and siRNA were performed for elucidating underlying mechanism. The roles of mitochondrial membrane potential and reactive oxygen species were investigated by flow cytometry using DiOC6 and DCFH-DA dye, respectively. Results SW1736 (wtp53) cells showed a higher apoptotic percentage than KAT4B (mutp53) cells in response to EVO stimulation via a flow cytometric analysis. Mechanistic studies showed that increased p53 and its downstream proteins, and disrupted MMP with increased intracellular peroxide production participated in EVO-induced apoptosis and G2/M arrest of SW1736 cells. In EVO-treated KAT4B cells, significant increases in G2/M percentage but little apoptotic events by EVO was observed. Structure-activity analysis showed that an alkyl group at position 14 was critical for induction of apoptosis related to ROS production and MMP disruption in SW1736 cells. Conclusion Evidence indicated that the endogenous p53 status affected the sensitivity of ATC cells to EVO-induced apoptosis and G2/M arrest, revealing the potential role of p53 related to increased ROS production and disrupted MMP in the anticancer actions of EVO, and alkylation at position 14 of EVO is a critical substitution for apoptosis of ATC cells.

Alginate-based 3D cell culture technique to evaluate the half-maximal inhibitory concentration: an in vitro model of anticancer drug study for anaplastic thyroid carcinoma

Background Three-dimensional (3D) cell culture methods are identified for simulating the biological microenvironment and demonstrating more similarity to in vivo circumstances. Anaplastic thyroid carcinoma (ATC) is a lethal endocrine malignancy. Despite different treatment approaches, no improvement in the survival rate of the patients has been shown. In this study, we used the 3D in vitro ATC model to investigate the cytotoxic effect of BI-847325 anticancer drug in two-dimensional (2D)- and 3D- cultured cells. Methods Human ATC cell lines, C643 and SW1736, were cultured in one percentage (w/v) sodium alginate. Spheroids were incubated in medium for one week. The reproducibility of the fabrication of alginate beads was evaluated. Encapsulation of the cells in alginate was examined by DAPI (4′,6-diamidino-2-phenylindole) staining. Survival of alginate-encapsulated cells was evaluated by CFSE (5,6-Carboxyfluorescein N-hydroxysuccinimidyl ester) staining. The population doubling times of C643 and SW1736 cell lines cultured in 2D monolayer as well as in 3D system were calculated. The cytotoxic effect of BI-847325 on 2D- and 3D- cultured cell lines was assessed for 24–72 h by MTT [3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide] assay. Finally, the 3D culture results were compared with the 2D culture method. Results The half-maximal inhibitory concentration (IC50) values of BI-847325 were higher in 3D culture compared to 2D culture. The cytotoxicity data indicated that 3D in vitro models were more resistant to chemotherapy agents. Conclusions The findings of this study are beneficial for developing in vitro ATC 3D models to analyze the efficacy of different chemotherapy drugs and formulations.

Survival in Anaplastic Thyroid Carcinoma: A Population-Based Analysis 1973-2015

Anaplastic thyroid carcinoma (ATC) is the least common and most aggressive of the thyroid cancers. ATC typically represents less than 5% of all thyroid cancer diagnoses but represents up to 50% of thyroid cancer deaths. The rarity of ATC lends itself to study by population-based studies. Methods. The most recent 1973-2015 Surveillance, Epidemiology, and End Results (SEER) database was queried for patients with a diagnosis of ATC. Data on demographics, overall survival, surgical treatment, and staging were extracted. Kaplan-Meier and log-rank analysis was used to evaluate for univariate survival differences, and logistic regression analysis was used to conduct a multivariate analysis. Results. A total of 1642 patients were identified (1021 female, 621 male). The largest age group was 75-79 years old, with the majority of patients older than 60. Univariate analysis showed that age at diagnosis, AJCC overall stage, T, N, and M stage, and surgical treatment vs. nonsurgical treatment significantly affected overall survival. Conclusions. Anaplastic thyroid carcinoma is a rare and aggressive malignancy. It has a relatively dismal prognosis, but younger age, surgical treatment, and lower stage improve overall survival outcomes.

MiRNA Deregulation Distinguishes Anaplastic Thyroid Carcinoma (ATC) and Supports Upregulation of Oncogene Expression

Anaplastic thyroid carcinoma (ATC) is the most fatal and rapidly evolving endocrine malignancy invading the head and neck region and accounts for up to 50% of thyroid cancer-associated deaths. Deregulation of the microRNA (miRNA) expression promotes thyroid carcinoma progression by modulating the reorganization of the ATC transcriptome. Here, we applied comparative miRNA–mRNA sequencing on a cohort of 28 thyroid carcinomas to unravel the association of deregulated miRNA and mRNA expression. This identified 85 miRNAs significantly deregulated in ATC. By establishing a new analysis pipeline, we unraveled 85 prime miRNA–mRNA interactions supporting the downregulation of candidate tumor suppressors and the upregulation of bona fide oncogenes such as survivin (BIRC5) in ATC. This miRNA-dependent reprogramming of the ATC transcriptome provided an mRNA signature comprising 65 genes sharply distinguishing ATC from other thyroid carcinomas. The validation of the deregulated protein expression in an independent thyroid carcinoma cohort demonstrates that miRNA-dependent oncogenes comprised in this signature, the transferrin receptor TFRC (CD71) and the E3-ubiquitin ligase DTL, are sharply upregulated in ATC. This upregulation is sufficient to distinguish ATC even from poorly differentiated thyroid carcinomas (PDTC). In sum, these findings provide new diagnostic tools and a robust resource to explore the key miRNA–mRNA regulation underlying the progression of thyroid carcinoma.

Thyroid crisis caused by metastatic thyroid cancer: an autopsy case report

Background Thyroid crisis is a life-threatening condition in thyrotoxic patients. Although differentiated thyroid cancer is one of the causes of hyperthyroidism, reports on thyroid crisis caused by thyroid cancer are quite limited. Here, we describe a case of thyroid crisis caused by metastatic thyroid cancer. Case presentation A 91-year-old woman was admitted to our hospital because of loss of appetite. Two years prior to this hospitalization, she presented with subclinical thyrotoxicosis and was diagnosed with histologically unidentified thyroid cancer with multiple metastases, and she refused aggressive medical interventions. On admission, she exhibited extreme thyrotoxicosis, and the presence of fever, severe tachycardia, impaired consciousness, and heart failure revealed the presence of thyroid crisis. All thyroid autoantibodies were negative. Multidisciplinary conservative treatment was initiated; however, she died on the fifth day after admission. Autopsy revealed the presence of primary anaplastic thyroid carcinoma and multiple metastatic foci arising from follicular thyroid carcinoma. Both primary and metastatic follicular thyroid carcinoma likely induced thyrotoxicosis, which could have been exacerbated by anaplastic thyroid carcinoma. Conclusions Even though the trigger of thyroid crisis in this patient is not clear, the aggravated progression of her clinical course suggests that careful monitoring of thyroid hormones and appropriate intervention are essential for patients with thyroid cancer.