Clinicopathological and Survival Outcomes of Well-Differentiated Thyroid Carcinoma Undergoing Dedifferentiation: A Retrospective Study from FUSCC

Primary small cell thyroid carcinoma combined with poorly differentiated thyroid carcinoma, evidence for a common origin: A case report

Primary small cell thyroid carcinomas are extremely rare and there is still debate about their classification as a distinct disease entity. The present case report reports a small cell carcinoma (SCC) combined with poorly differentiated thyroid carcinoma (PDTC) in a 34 year old man. The tumor consisted of ~80% PDTC and ~20% SCC. The PDTC component was positive for cytokeratin and thyroid transcription factor-1 (TTF-1), and negative for calcitonin, chromogranin and synaptophysin. The SCC component was positive for synaptophysin and CD56, and negative for calcitonin, chromogranin and TTF-1. Seven months after thyroid surgery, two new lung nodules were detected. Histologically and immunohistochemically, the lung tumors were similar to the SCC component of the thyroid carcinoma. The mutational status of cancer-related genes was assessed using targeted next-generation sequencing in both the thyroid and lung, which identified similar genetic alterations. The histogenesis of SCC was evaluated through NGS analysis of the two cancer components.

LINC00886 Negatively Regulates Malignancy in Anaplastic Thyroid Cancer

Anaplastic thyroid cancer (ATC) is the most aggressive type of thyroid cancer. This study aimed to identify specific long noncoding RNAs (lncRNAs) associated with ATC, and further investigated their biological functions and molecular mechanism underlying regulation of malignancy in ATC. We searched for lncRNAs associated with dedifferentiation and screened out specific lncRNAs significantly deregulated in ATC by using transcriptome data of dedifferentiation cancers from Fudan University Shanghai Cancer Center (FUSCC) and the Gene Expression Omnibus (GEO) database. The above lncRNAs were analyzed to identify a potential biomarker in thyroid cancer patients from the FUSCC, GEO, and The Cancer Genome Atlas, which was then investigated for its functional roles and molecular mechanism in ATC in vitro. The clinicopathological association analyses revealed that LINC00886 expression was significantly correlated with dedifferentiation and suppressed in ATC. In vitro, LINC00886 was confirmed to negatively regulate cell proliferation, and cell migration and invasion of ATC. LINC00886 physically interacted with protein kinase R (PKR) and affected its stability through the ubiquitin/proteasome-dependent degradation pathway in the ATC cell. Decreased PKR caused by downregulation of LINC00886 enhanced the activity of eukaryotic initiation factor 2α (eIF2α) via reducing phosphorylation of eIF2α and thus promoted protein synthesis to maintain ATC malignancy. Our findings identify LINC00886 as a novel biomarker of thyroid cancer and suggest that LINC00886/PKR/eIF2α signaling is a potential therapeutic target in ATC.

Targeting Tumor Hypoxia Inhibits Aggressive Phenotype of Dedifferentiated Thyroid Cancer

CONTEXT

Hypoxia is commonly observed in multiple aggressive cancers. Its role remains unclear in the biology and therapy of dedifferentiated thyroid cancer (DDTC).

OBJECTIVE

We aimed to elucidate hypoxia's roles in DDTC tumor biology.

METHODS

We discovered and confirmed hypoxia's correlation with dedifferentiation status, poor prognoses, and immune checkpoints in thyroid cancer using transcriptome data from our center and Gene Expression Omnibus (GEO) database. Then, the effect of targeting hypoxia was investigated via treating anaplastic thyroid cancer (ATC) cells with acriflavine (ACF) in vitro and in vivo, and hypoxia was analyzed for its association with response to immunotherapy in patients.

RESULTS

Hypoxia score was positively associated with dedifferentiation status, and high hypoxia score significantly correlated with reduced overall survival, TP53 mutation, and elevated expression of immunosuppression-related markers in DDTC. ACF and siRNA targeting HIF-1α significantly suppressed growth and proliferation of thyroid cancer cells in vitro and in vivo, and reduced c-MYC and PDL1 expression in ATC. HIF-1α showed a positive correlation with PDL1 expression in DDTC. Integrated analyses of phosphoproteome and RNA sequencing data revealed that ACF's target was connected with differentiation genes and immune checkpoints via tumor-related kinases in ATC. Furthermore, hypoxia score was associated with immunotherapeutic response in some cancer types.

CONCLUSION

Hypoxia score serves as a significant indicator for dedifferentiation status, prognoses, and immunotherapeutic response predicted by Tumor Immune Dysfunction and Exclusion in DDTC patients. Targeting hypoxia by ACF is useful to alleviate aggressive phenotype of ATC in a preclinical model of DDTC.

MMP1 acts as a potential regulator of tumor progression and dedifferentiation in papillary thyroid cancer

Papillary thyroid cancer (PTC) is one of the malignancies with an excellent prognosis. However, in PTC, progression or dedifferentiation into poorly differentiated thyroid cancer (PDTC) or anaplastic thyroid cancer (ATC) extremely jeopardizes patients’ prognosis. MMP1 is a zinc-dependent endopeptidase, and its role in PTC progression and dedifferentiation is unclear. In this study, transcriptome data of PDTC/ATC and PTC from the Gene Expression Omnibus and The Cancer Genome Atlas databases were utilized to perform an integrated analysis of MMP1 as a potential regulator of tumor progression and dedifferentiation in PTC. Both bulk and single-cell RNA-sequencing data confirmed the high expression of MMP1 in ATC tissues and cells, and further study verified that MMP1 possessed good diagnostic and prognostic value in PTC and PDTC/ATC. Up-regulated MMP1 was found to be positively related to more aggressive clinical characteristics, worse survival, extracellular matrix-related pathways, oncogenic immune microenvironment, more mutations, higher stemness, and more dedifferentiation of PTC. Meanwhile, in vitro experiments verified the high level of MMP1 in PDTC/ATC cell lines, and MMP1 knockdown and its inhibitor triolein could both inhibit the cell viability of PTC and PDTC/ATC. In conclusion, our findings suggest that MMP1 is a potential regulator of tumor progression and dedifferentiation in PTC, and might become a novel therapeutic target for PTC, especially for more aggressive PDTC and ATC.

Hobnail variant of papillary thyroid carcinoma with anaplastic dedifferentiation co-existent with tuberculosis lymphadenitis

Introduction

The current study aims to report a rare case of metastatic papillary thyroid carcinoma (PTC) of the cervical lymph nodes with hobnail variant and anaplastic de-differentiation. In addition to the primary disease, there was a second pathology which was caseating granulomatous lymph adenitis suggestive of tuberculosis.

Case report

A 91-year-old female presented with a painful right sided neck swelling for two weeks, increased in size suddenly. On clinical examination, there was a well-defined firm painful right sided neck mass. On ultrasound examination, there was multiple well defined solid hypoechoic, hypervascular nodules. These resembled lymph nodes of variable size and shape, mostly in the right side. The patient underwent right lateral cervical lymph node dissection. After the operation, she was sent for radiotherapy.

Discussion

The hobnail variant of PTC is genetically identical to poorly differentiated thyroid carcinoma in that its mutations are in the p53 and TERT promoters are more common in this variant than in conventional PTCs. The proportion of hobnail features have no effect on the outcome. Additionally, 10% of tumor cells with hobnail features were previously linked to a more aggressive clinicopathological aspect.

Conclusion

Although it is rare, metastatic PTC with hobnail variant could undergo anaplastic dedifferentiation.

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Thyroid carcinoma accounts for nearly 1% of all malignancies.

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The hobnail variant of papillary thyroid carcinoma (HPTC) is a rare condition.

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Anaplastic thyroid carcinoma (ATC) is a rare form of thyroid cancer.

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Malignant lesions and tuberculosis coexisting at the same site is exceedingly unusual.

Enhancement of nanoparticle-mediated double suicide gene expression driven by 'E9-hTERT promoter' switch in dedifferentiated thyroid cancer cells

Differentiated thyroid cancer (DTC), such as papillary thyroid cancer, has a good prognosis after routine treatment. However, in the course of treatment, 5% to 20% of cases may dedifferentiate and can be transformed into dedifferentiated DTC (deDTC) or anaplastic thyroid cancer, leading to treatment failure. To date, several drugs have been used effectively for dedifferentiated thyroid cancer, whereas gene therapy may be a potential method. Literature reported that double suicide genes driven by human telomerase reverse transcriptase promoter (hTERTp) can specifically express in cancer cells and kill them. However, the weak activity of hTERTp limits its further research. To overcome this weakness, we constructed a novel chitosan nanocarrier containing double suicide genes driven by a ‘gene switch’ (a cascade of radiation enhancer E9 and a hTERTp). The vector was labeled with iodine-131 (¹³¹I). On one hand, E9 can significantly enhance the activity of hTERTp under the weak radiation of ¹³¹I, thereby increasing the expression of double suicide genes in deDTC cells. On the other hand, ¹³¹I also plays a certain killing role when it enters host cells. The proposed nanocarrier has good specificity for deDTC cells and thus deserves further study.

Identification of Key Functional Gene Signatures Indicative of Dedifferentiation in Papillary Thyroid Cancer

Background: Differentiated thyroid cancer (DTC) is the most common type of thyroid cancer. Many of them can relapse to dedifferentiated thyroid cancer (DDTC) and exhibit different gene expression profiles. The underlying mechanism of dedifferentiation and the involved genes or pathways remained to be investigated.

Methods: A discovery cohort obtained from patients who received surgical resection in the Fudan University Shanghai Cancer Center (FUSCC) and two validation cohorts derived from Gene Expression Omnibus (GEO) database were used to screen out differentially expressed genes in the dedifferentiation process. Weighted gene co-expression network analysis (WGCNA) was constructed to identify modules highly related to differentiation. Gene Set Enrichment Analysis (GSEA) was used to identify pathways related to differentiation, and all differentially expressed genes were grouped by function based on the GSEA and literature reviewing data. Least absolute shrinkage and selection operator (LASSO) regression analysis was used to control the number of variables in each group. Next, we used logistic regression to build a gene signature in each group to indicate differentiation status, and we computed receiver operating characteristic (ROC) curve to evaluate the indicative performance of each signature.

Results: A total of 307 upregulated and 313 downregulated genes in poorly differentiated thyroid cancer (PDTC) compared with papillary thyroid cancer (PTC) and normal thyroid (NT) were screened out in FUSCC cohort and validated in two GEO cohorts. WGCNA of 620 differential genes yielded the seven core genes with the highest correlation with thyroid differentiation score (TDS). Furthermore, 395 genes significantly correlated with TDS in univariate logistic regression analysis were divided into 11 groups. The areas under the ROC curve (AUCs) of the gene signature of group transcription and epigenetic modification, signal and substance transport, extracellular matrix (ECM), and metabolism in the training set [The Cancer Genome Atlas (TCGA) cohort] and validation set (combined GEO cohort) were both >0.75. The gene signature based on group transcription and epigenetic modification, cilia formation and movement, and proliferation can reflect the patient's disease recurrence state.

Conclusion: The dedifferentiation of DTC is affected by a variety of mechanisms including many genes. The gene signature of group transcription and epigenetic modification, signal and substance transport, ECM, and metabolism can be used as biomarkers for DDTC.

Cancer-Associated Fibroblasts Positively Correlate with Dedifferentiation and Aggressiveness of Thyroid Cancer

Background and Objectives

Targeting cancer-associated fibroblast (CAF) is being explored as an approach to improve cancer therapies. The roles of CAF remain unclarified in malignant transformation of papillary thyroid cancer (PTC) into dedifferentiated thyroid cancer (DDTC). This study aimed to investigate correlations of CAF with dedifferentiation and clinicopathological characteristics of thyroid cancer.

Materials and Methods

We applied three different mRNA-based CAF gene signatures to quantify CAF in our cohort, the Gene Expression Omnibus (GEO) cohort and The Cancer Genome Atlas (TCGA) cohort, and analyzed expression of α-SMA by immunohistochemistry in thyroid cancer. The CAF score was analyzed for its associations with clinicopathological characteristics, genetic mutations, tumor-associated signaling pathways and immune landscape.

Results

The CAF score increased significantly in DDTCs compared with normal thyroid tissues and PTCs, and the α-SMA-positive CAFs were found enriched in DDTCs. The high CAF score showed a significant correlation with the anaplastic phenotype in DDTC and low thyroid differentiation score in PTC. Patients with a high CAF score remarkably increased the risk of aggressive outcomes in both DDTC and PTC. Furthermore, the CAF score was positively correlated with genetic mutations, oncogenic signaling pathways, the immune score and increased expression of tumor microenvironment (TME) target markers.

Conclusion

Our findings suggest CAFs positively correlate with dedifferentiation and aggressive outcomes of thyroid cancer, and targeting CAFs as a therapeutic approach may benefit DDTC patients.

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.

Arms-qPCR Improves Detection Sensitivity of Earlier Diagnosis of Papillary Thyroid Cancers With Worse Prognosis Determined by Coexisting BRAF V600E and Tert Promoter Mutations

OBJECTIVE

The coexistence of BRAF V600E and the telomerase reverse transcriptase (TERT) promoter mutation C228T/C250T is extensively associated with thyroid cancer prognosis. Our study aimed to establish a sensitive method for mutation detection and explore the correlation in detail.

METHODS

The BRAF and TERT promoter mutation status of 250 papillary thyroid cancers was determined using amplification-refractory mutation system quantitative polymerase chain reaction (ARMS-qPCR) and Sanger sequencing to compare the sensitivity of the 2 methods. Associations between the mutation status and clinicopathological features were then analyzed.

RESULTS

ARMS-qPCR was more sensitive than Sanger sequencing (BRAF V600E: 75.2% [188 of 250] vs 52.4% [131 of 250], P < .001; TERT promoter C228T/C250T mutation: 12.0% [30 of 250] vs 3.6% [9 of 250], P = .001; comutation: 9.6% [24 of 250] vs 3.2% [8 of 250], P = .005). Both ARMS-qPCR and Sanger sequencing indicated that patients with coexisting BRAF V600E and TERT promoter mutations had an older diagnosis age, higher recurrence rate, and were associated with a more advanced TNM stage and higher metastasis, age, completeness of resection, invasion, and size score. Moreover, ARMS-qPCR helped identify an earlier group stage, which was younger and had smaller tumors and a lower recurrence rate, compared with the group with coexisting BRAF V600E and TERT promoter mutations identified by Sanger sequencing. The newly identified group had a lower metastasis, age, completeness of resection, invasion, and size score and TNM stage.

CONCLUSION

Patients with coexisting BRAF V600E and TERT promoter mutations had a worse prognosis. ARMS-qPCR, the more sensitive method, can be used to identify patients who have a potentially worse prognosis earlier.

Current Trends in ATRA Delivery for Cancer Therapy

All-Trans Retinoic Acid (ATRA) is the most active metabolite of vitamin A. It is critically involved in the regulation of multiple processes, such as cell differentiation and apoptosis, by activating specific genomic pathways or by influencing key signaling proteins. Furthermore, mounting evidence highlights the anti-tumor activity of this compound. Notably, oral administration of ATRA is the first choice treatment in Acute Promyelocytic Leukemia (APL) in adults and NeuroBlastoma (NB) in children. Regrettably, the promising results obtained for these diseases have not been translated yet into the clinics for solid tumors. This is mainly due to ATRA-resistance developed by cancer cells and to ineffective delivery and targeting. This up-to-date review deals with recent studies on different ATRA-loaded Drug Delivery Systems (DDSs) development and application on several tumor models. Moreover, patents, pre-clinical, and clinical studies are also reviewed. To sum up, the main aim of this in-depth review is to provide a detailed overview of the several attempts which have been made in the recent years to ameliorate ATRA delivery and targeting in cancer.

Polymer Nanoformulation of Sorafenib and All-Trans Retinoic Acid for Synergistic Inhibition of Thyroid Cancer

Part of differentiated thyroid cancer will relapse or develop into dedifferentiated thyroid cancer after standard therapy, such as surgery or radionuclide therapy. Sorafenib (SOR) is recommended for the treatment of advanced or radioiodine-refractory thyroid cancer. The monotherapy using SOR is often hampered by its modest efficacy, serve systemic toxicity, and high occurrence of drug resistance. In order to enhance the antitumor effect of SOR and reduce its side effects, SOR and all-trans retinoic acid (ATRA), a differentiation-promoting drug, were loaded into poly(ethylene glycol)–poly(lactide-co-glycolide) (PEG–PLGA) polymer micelles in this study. The drug-loaded micelles, PM/(SOR+ATRA), exhibited relatively slow drug release and effective cell uptake. Compared with other treatment groups, the PM/(SOR+ATRA) treatment group showed the most significant antitumor effect and minimal systemic toxicity toward the FTC-133 thyroid cancer-bearing BALB/c nude mouse model. Immunofluorescence analysis confirmed that PM/(SOR+ATRA) could significantly promote apoptosis and re-differentiation of tumor cells. All the results demonstrated that polymer micelles loaded with SOR and ATRA could treat thyroid cancer more effectively and safely.

A combination of captopril challenge test after saline infusion test improves diagnostic accuracy for primary aldosteronism

CONTEXT

The saline infusion test (SIT) is a common confirmatory test for primary aldosteronism (PA). According to the guideline, a postinfusion plasma aldosterone concentration (PAC) of 5-10 ng/dL is considered indeterminate, and recommendations for diagnostic strategies are currently limited in this situation.

OBJECTIVE

To explore whether an addition of the captopril challenge test (CCT) could improve the diagnostic accuracy in patients with indeterminate SIT.

METHODS

A total of 280 hypertensive patients with high risk of PA completed this study. Subjects were defined as SIT indeterminate based on their PAC post-SIT. These patients then underwent the CCT where PACs post-CCT >11 ng/dL were considered positive. Using fludrocortisone suppression test (FST) as the reference standard, diagnostic parameters including area under the receiver-operator characteristic curves (AUC), sensitivity and specificity were calculated.

RESULTS

There were 65 subjects (23.2%) diagnosed as PA indeterminate after SIT. With the addition of CCT, true-positive numbers increased from 134 to 147, and false-negative numbers decreased from 27 to 14. Compared to SIT alone, a combination of SIT and CCT showed a higher AUC (0.91 [0.87,0.94] vs 0.87 [0.83,0.91], P = .041) and an increased sensitivity for the diagnosis of PA (0.91 [0.86,0.95] vs 0.83 [0.76,0.89], P = .028), while the specificity remained similar. In the subgroup with indeterminate SIT results, using PAC post-CCT resulted in a 36% higher AUC than using PAC post-SIT alone for the diagnosis of PA.

CONCLUSION

For patients under investigation for possible PA who have indeterminate SIT results, an addition of CCT improves the diagnostic accuracy.

Transcriptome Analyses Identify a Metabolic Gene Signature Indicative of Dedifferentiation of Papillary Thyroid Cancer

CONTEXT

Metabolic reprogramming is a common feature of tumorigenesis. It remains unknown concerning the expression pattern of metabolism-associated genes in dedifferentiated thyroid cancer (DDTC).

OBJECTIVE

This study aimed to identify a useful signature to indicate dedifferentiation of papillary thyroid cancer (PTC).

DESIGN AND SETTING

We used one discovery and two validation cohorts to screen out aberrant metabolic genes in DDTC, and further used The Cancer Genome Atlas (TCGA) cohort to search for independent risk factors for the low-differentiated phenotype of PTC as a signature of dedifferentiation. The prediction of the signature for DDTC was validated in the TCGA cohort and the combined Gene Expression Omnibus cohort. We also analyzed the correlations of the signature risk score with clinicopathological features of PTC. Gene set enrichment analyses were performed in the TCGA cohort.

RESULTS

Significant enrichment of metabolic pathways correlated with differentiation status of PTC. A signature of metabolic genes including LPCAT2, ACOT7, HSD17B8, PDE8B, and ST3GAL1 was discovered and validated across three cohorts. The signature was not only predictive of DDTC but also significantly associated with BRAFV600E mutation (P < 0.001), T3/T4 stage (P < 0.001), extrathyroidal extension (P < 0.001), lymph node metastasis (P < 0.001), and tumor/lymph node/metastasis III/IV stage (P < 0.001) in PTC. Downregulations of LPCAT2 expression (P = 0.009) and ST3GAL1 expression (P = 0.005) increased risks of decreased disease-free survival for patients. Furthermore, the signature was implicated in a number of oncogenic biological pathways.

CONCLUSIONS

Our findings suggest that metabolic deregulations mediate dedifferentiation of PTC, and that the metabolic gene signature can be used as a biomarker for DDTC.