Synergistic effect of metformin and vemurufenib (PLX4032) as a molecular targeted therapy in anaplastic thyroid cancer: an in vitro study.

BACKGROUND: Survival rate of patients affected with anaplastic thyroid carcinoma (ATC) is less than 5% with current treatment. In ATC, BRAFV600E mutation is the major mutation that results in the transformation of normal cells in to an undifferentiated cancer cells via aberrant molecular signaling mechanisms. Although vemurufenib is a selective oral drug for the BRAFV600E mutant kinase with a response rate of nearly 50% in metastatic melanoma, our study has showed resistance to this drug in ATC. Hence the rationale of the study is to explore combinational therapeutic effect to improve the efficacy of vemurafenib along with metformin. Metformin, a diabetic drug is an AMPK activator and has recently proved to be involved in preventing or treating several types of cancer. METHODS AND RESULTS: Using iGEMDock software, a protein-ligand interaction was successful between Metformin and TSHR (receptor present in the thyroid follicular cells). Our study demonstrates that combination of vemurufenib with metformin has synergistic anti-cancer effects which was evaluated through MTT assay (cytotoxicity), colony formation assay (antiproliferation evaluation) and suppressed the progression of ATC cells growth by inducing significant apoptosis, proven by Annexin V-FITC assay (Early Apoptosis Detection). Downregulation of ERK signaling, upregulation of AMPK pathway and precision in epithelial-mesenchymal transition (EMT) pathway which were assessed by RT-PCR and Western blot provide the evidence that the combination of drugs involved in the precision of altered molecular signaling Further our results suggest that Metformin act as a demethylating agent in anaplastic thyroid cancer cells by inducing the expression of NIS and TSHR. Our study for the first time explored cAMP signaling in ATC wherein cAMP signaling is downregulated due to decrease in intracellular cAMP level upon metformin treatment. CONCLUSION: To conclude, our findings demonstrate novel therapeutic targets and treatment strategies for undifferentiated ATC.

FGF-Receptors and PD-L1 in Anaplastic and Poorly Differentiated Thyroid Cancer: Evaluation of the Preclinical Rationale.

Background: Treatment options for poorly differentiated (PDTC) and anaplastic (ATC) thyroid carcinoma are unsatisfactory and prognosis is generally poor. Lenvatinib (LEN), a multi-tyrosine kinase inhibitor targeting fibroblast growth factor receptors (FGFR) 1-4 is approved for advanced radioiodine refractory thyroid carcinoma, but response to single agent is poor in ATC. Recent reports of combining LEN with PD-1 inhibitor pembrolizumab (PEM) are promising. Materials and Methods: Primary ATC (n=93) and PDTC (n=47) tissue samples diagnosed 1997-2019 at five German tertiary care centers were assessed for PD-L1 expression by immunohistochemistry using Tumor Proportion Score (TPS). FGFR 1-4 mRNA was quantified in 31 ATC and 14 PDTC with RNAscope in-situ hybridization. Normal thyroid tissue (NT) and papillary thyroid carcinoma (PTC) served as controls. Disease specific survival (DSS) was the primary outcome variable. Results: PD-L1 TPS≥50% was observed in 42% of ATC and 26% of PDTC specimens. Mean PD-L1 expression was significantly higher in ATC (TPS 30%) than in PDTC (5%; p<0.01) and NT (0%, p<0.001). 53% of PDTC samples had PD-L1 expression ≤5%. FGFR mRNA expression was generally low in all samples but combined FGFR1-4 expression was significantly higher in PDTC and ATC compared to NT (each p<0.001). No impact of PD-L1 and FGFR 1-4 expression was observed on DSS. Conclusion: High tumoral expression of PD-L1 in a large proportion of ATCs and a subgroup of PDTCs provides a rationale for immune checkpoint inhibition. FGFR expression is low thyroid tumor cells. The clinically observed synergism of PEM with LEN may be caused by immune modulation.

Coexisting well-differentiated and anaplastic thyroid carcinoma in the same primary resection specimen: immunophenotypic and genetic comparison of the two components in a consecutive series of 13 cases and a review of the literature.

Anaplastic carcinoma (AC) is a rare but highly aggressive form of thyroid cancer. It mostly arises on a background of pre-existing well-differentiated cancer (WDC); however, whether it evolves directly from a WDC or originates as a second independent neoplasm is still to be defined. To obtain further insights into these mechanisms, we performed morphological, immunohistochemical, and next-generation sequencing analyses to compare AC and its associated WDC in a subset of 13 surgically resected specimens. Histologically, most WDC were of aggressive subtypes. Papillary carcinomas (8 cases; 62%) were tall cell (4/8), columnar (1/8), classic with hobnail features (1/8), classic and follicular variant in the remaining 2 cases; Hürthle cell and follicular carcinomas were present in 5 (38%) and in 1 (8%) patient, respectively. One patient harbored both a PTC, follicular variant, and a Hürthle cell carcinoma. We did not find any correlation between a histotype of WDC and a specific anaplastic growth pattern. Immunohistochemically, ACs retained pankeratin/PAX8 expression but with significantly lower levels than WDCs, and they tended to lose TTF1 expression, as can be expected within a dedifferentiation process. In addition, AC showed a more frequent expression of p63 and/or SMA, a mutated pattern of p53, and an abnormal expression of p16. Genetic analysis showed that the number of mutations was higher in AC than in the associated WDC, confirming a role of the progressive accumulation of genetic damage in this transition. We observed that mutations found in the WDCs were consistently identified in the anaplastic counterparts, further supporting the hypothesis of a developmental link.

Anaplastic thyroid carcinoma: an epidemiologic, histologic, immunohistochemical, and molecular single-institution study.

Anaplastic thyroid carcinoma (ATC) is a highly aggressive form of thyroid cancer. A single-institution thyroid cancer cohort of ATC was identified within the last 10 years at our institution. Retrospective analysis revealed that the frequency of ATC was 0.5% (11/2106 thyroid carcinomas). The average age at diagnosis of ATC was 74 years, and the female-to-male ratio was 1.2:1. ATC presented as a rapidly enlarging neck mass involving predominantly the left thyroid lobe (7/11; 64%). Cervical adenopathy was present in 7 (64%) of 11 cases. Fifty-five percent (6/11) of patients had distant metastases at the time of diagnosis. Histologically, ATC closely simulated a large variety of soft tissue sarcomas; osteoclast-like giant cell-rich tumors; squamous cell, spindle cell, and small cell carcinomas; and anaplastic/large cell lymphomas. Four tumors (4/11; 36%) showed heterologous elements, including rhabdoid and chondroid differentiation. Immunohistochemical studies showed that all ATCs lost TTF-1 and thyroglobulin expression, whereas PAX-8 expression was identified in 36% (4/11) of tumors. Intense and extensive nuclear staining of p53 (>50%) and high Ki-67 proliferative rate (>30%) were seen in all ATCs (11/11; 100%). Next-generation sequencing revealed recurrent BRAF V600E and TP53 gene mutations. Individual examples of a BRAF G469A mutation in ATC with follicular carcinoma component, EGFR, PTEN, PIK3CA, and FGFR3 mutations, were also identified, whereas 1 case of ATC showed wild-type sequencing with no identifiable alterations.

Thyroglobulin Determination in Fine Needle Aspiration Biopsy Washout of Suspicious Lymph Nodes in Thyroid Carcinoma Follow up.

BACKGROUND: Differentiated thyroid carcinomas (DTCs) account for about 1% of all human malignancies. Cervical lymph nodes metastases and recurrences in the thyroid bed frequently occur. Furthermore, about 10-15% of patients develop distant metastases. Therefore, patients must undergo life-long follow-up. OBJECTIVE: The aim of this study was to evaluate the usefulness of Thyroglobulin measurement in FNAB washout (FNAB-Tg) in the detection of local metastasis in patients affected by or evaluated for thyroid cancer. MATERIALS AND METHODS: In a 3-year period, a total of 83 consecutive patients coming to our attention at the Ear-Nose-Throat (ENT) Outpatients Service of the National Cancer Research Center &quot;Istituto Tumori Giovanni Paolo II&quot; of Bari, Italy, because of the finding of one or more cervical lymph node(s), were enrolled in the study. After collection of the cytological specimen, the needle used for performing FNAB was then washed in 1 ml of normal saline. 89 FNAB washouts were collected from the same number of lymph nodes and subsequently investigated for Thyroglobulin levels using a sequential chemiluminescent-immunometric assay. RESULTS: Comparing the cytological or, when performed, histological diagnoses with the results of FNAB-Tg, we found that in 24 cases of lymph node metastases from PTC (19 lymph nodes from patients at the first diagnoses and 5 lymph nodes from PTC patients in follow up) the mean level of Thyroglobulin was 1840.11 ng/ml; range: <0,2 to 11440 ng/ml. In the group of PTC patients (27 lymph nodes) with lymph nodes negative for metastatic involvement at cytology (i.e. no lymph node recurrence at follow-up), as well as in the cases of subjects without PTC and submitted to FNAB because of the appearance of lymph node(s) classified as reactive at cytology (37 lymph nodes), FNAB-Tg was lower than or equal to 0.2 ng/ml. As expected, the Thyroglobulin level was not detectable (< 0.2 ng/ml) also in a lymph node FNAB from a case of anaplastic thyroid carcinoma. CONCLUSION: In our study, FNAB-Tg was not detectable in all node negative patients showing, when considering together all the lymph node metastases, a 96% sensitivity and 100% specificity.

A study of FoxA1 expression in thyroid tumors.

FoxA1 regulates a variety of tissues during embryogenesis and early life. In thyroid, FoxA1 expression has recently been shown in C cells and medullary thyroid carcinomas but not in follicular cells. FoxA1 has also been proposed as a potential oncogene in anaplastic thyroid carcinomas. However, FoxA1 expression has not been extensively investigated in a spectrum of thyroid nonneoplastic lesions and tumors. A variety of thyroid tumors and lesions and their morphologic mimics were stained with monoclonal anti-FoxA1 antibody. For the medullary carcinomas, its expression pattern was compared with those of other conventional markers. All 67 medullary thyroid carcinomas (100%), including 1 calcitonin-negative medullary carcinoma, showed diffuse and strong FoxA1 nuclear expression. The expression pattern was homogeneous throughout the tumor. Expressions of other markers in medullary thyroid carcinomas were as follows: calcitonin, 94.7%; CEA, 91.2%; and chromogranin, 100%, generally in variable intensity. FoxA1 was completely negative in follicular neoplasms, papillary thyroid carcinomas, and poorly differentiated carcinomas, whereas it was expressed in 55% of anaplastic thyroid carcinomas (33/60) in variable intensity. FoxA1 was also strongly expressed in C-cell hyperplasia as well as solid cell nests. No FoxA1 expression was seen in thyroid gland affected by nodular hyperplasia, Hashimoto thyroiditis, and Graves disease, or in paragangliomas or parathyroid lesions. FoxA1 discriminates between medullary thyroid carcinoma and tumors of follicular derivation with sensitivity and specificity greater than calcitonin and CEA; therefore, it may serve as a reliable ancillary marker for the diagnosis of medullary thyroid carcinoma because of its reliably uniform quality of staining.

E-cadherin/α-catenin deregulated co-expression in thyroid carcinoma based on tissue microarray digital image analysis.

PURPOSE: Deregulation of cell-to-cell adhesion molecules is a common and also critical genetic event in epithelial malignancies leading to an increasing metastatic potential. Among them, e-cadherin and catenins--especially α and ß--, act as oncogenes during the carcinogenetic process affecting specific signaling transduction pathways (i.e. Wnt/ b-catenin). Concerning thyroid carcinoma, decreased or loss of expression in these proteins seems to affect the biological behavior of the neoplasm increasing its aggressiveness. The aim of this study was to investigate the deregulation of e-cadherin/α-catenin complex in thyroid carcinomas. METHODS: Thirty-five paraffin-embedded tissue samples including thyroid carcinomas (N=20) and also 15 cases of benign follicular nodules were cored at 1 mm diameter and transferred to a microarray block. Immunohistochemistry (IHC) was performed using anti-e-cadherin/α-catenin antibodies. Digital image analysis was also implemented for measuring the corresponding protein expression levels. RESULTS: E-cadherin/α-catenin protein expression demonstrated a significant progressive decrease regarding benign and malignant lesions (p=0.001). Simultaneous e-cadherin/α-catenin reduced or loss of expression was observed in 10/20 (50%) cancer cases correlated to advanced stage (especially nodal metastasis) of the examined tumours (p=0.02). Concerning the histological type, combined loss of e-cadherin/α-catenin expression was predominantly associated with follicular and anaplastic histology (p=0.001). Interestingly, α-catenin protein expression pattern was significantly correlated with the grade of differentiation of the examined malignancies (p=0.01). CONCLUSIONS: Progressive loss of e-cadherin mainly and also α-catenin expression is associated with an aggressive phenotype (low differentiation, increased metastatic activity/advanced stage) in thyroid carcinomas. Based on their aberrant protein expression, novel agents have been developed for restoring their normal function.

Total synthesis and structural revision of mycalol, an anticancer natural product from the marine source.

The total synthesis of an anticancer (anaplastic thyroid) natural lipid mycalol has been accomplished for the first time. Synthesis of originally proposed structure necessitated the revision of structure in which the position of acetate group moved from C20 to C19 and a change in stereochemistry of the glycerol unit.

Undifferentiated (anaplastic) thyroid carcinoma: Practical immunohistochemistry and cytologic look-alikes.

Aspirate smears of undifferentiated (anaplastic) thyroid carcinoma (ATC) are, in most instances, readily recognized as malignant. Nonetheless, pitfalls exist with this neoplasm in part due to the absence of epithelial markers, overlapping features with other malignancies that may metastasize to or arise within the thyroid, and potential confusion with non-neoplastic conditions that simulate malignancy. We highlight the salient morphologic features of ATC and its variants, useful discriminatory ancillary immunostains to recognize it, and ATC mimickers that have the potential to confuse the cytopathologist.