Downregulation of AKT/mTOR signaling pathway for Salmonella-mediated autophagy in human anaplastic thyroid cancer

Thyroid cancer has been known as the most common endocrine malignancy. Although majority of thyroid cancer types respond well to conventional treatment including surgery and radioactive iodine therapy, about 10% of those with differentiated thyroid cancer will present distant metastasis and will have persistent or recurrent disease. Even more serious is a rare type of thyroid cancer called anaplastic thyroid cancer (ATC), which accounts for about 1%, has been demonstrated as the most lethal and aggressive form of human malignancy. Unfortunately, these tumors are also frequently resistant to traditional therapy. Previous study have shown that Salmonella inhibits tumor growth, in part, by inducing autophagy - a cellular process that is important in the innate and adaptive immunity in response to viral or bacterial infection. In our study, we intended to investigate whether Salmonella can inhibit tumor growth by inducing autophagy, specifically in thyroid cancer and elucidate the possible molecular mechanism. In order to determine the signaling pathway involved in tumor cell autophagy, we used Salmonella to treat ATC cells line ASH-3 and KMH-2 in vitro. The autophagic markers, particularly autophagy-related gene 6 (Beclin-1), microtubule-associated protein 1A/1B-light chain 3 (LC3) and p62, were observed to be differentially expressed after infection with Salmonella indicating an activated autophagy in ATC cells. In addition, the protein expression levels of phospho-protein kinase B (P-AKT), phospho-mammalian targets of rapamycin (P-mTOR), phospho-p70 ribosomal s6 kinase (P-p70S6K) in tumor cells were decreased after Salmonella infection. In vivo, we also found that substantial cell numbers of Salmonella targeted tumor tissue, and regulated anti-tumor mechanisms. Our findings showed that Salmonella activated autophagic signaling pathway and inhibited ATC tumor growth via downregulation of AKT/mTOR pathway.

Blocking CDK7-Mediated NOTCH1-cMYC Signaling Attenuates Cancer Stem Cell Activity in Anaplastic Thyroid Cancer

Background: Anaplastic thyroid cancer (ATC) is an aggressive solid cancer in humans with few treatment options. Recent studies suggest that aberrant gene transcription could contribute to aggressive ATC progression. To test this hypothesis, we assessed if blocking cyclin-dependent protein 7 (CDK7) activity could impede ATC progression through attenuation of cancer stem cell (CSC) activity. Methods: We treated cell lines isolated from human ATC (THJ-11T and -16T) and xenograft mice induced by these cells with the CDK7 inhibitor THZ1. Through integrative transcriptome analyses we found that the NOTCH1-cMYC signaling axis was a potential target of CDK7 inhibition in ATC. To determine the regulatory action of NOTCH1-cMYC signaling in CSC maintenance, we evaluated the effect of a selective NOTCH1 inhibitor, crenigacestat, on CSC capacities in ATC. Results: THZ1 markedly inhibited proliferation of ATC cells and xenograft tumor growth by blocking cell cycle progression and inducing apoptosis. NOTCH1 was sensitive to suppressive transcription mediated by CDK7 inhibition and was highly enriched in tumorspheres from ATC cells. Treatment of ATC cells with either crenigacestat or THZ1 blocked formation of tumorspheres, decreased aldehyde dehydrogenase activity, and suppressed in vivo initiation and growth of tumors induced by ATC cells, indicating that NOTCH1 was a critical regulator of CSC activity in ATC. Furthermore, we demonstrated that cMYC was a downstream target of NOTCH1 signaling that collaboratively maintained CSC activity in ATC. Of note, genomic analysis showed that low CDK7 expression contributed to longer disease-free survival of thyroid cancer patients. Conclusions: NOTCH1 is a newly identified CSC regulator. Targeting NOTCH1-cMYC signaling is a promising therapeutic strategy for ATC.

A Pilot Study of Durvalumab (MEDI4736) with Tremelimumab in Combination with Image-Guided Stereotactic Body Radiotherapy in the Treatment of Metastatic Anaplastic Thyroid Cancer

Background: Metastatic anaplastic thyroid cancer (ATC) has a poor prognosis. This pilot study aims to evaluate tremelimumab plus durvalumab with stereotactic body radiotherapy (SBRT) to improve overall survival (OS). Methods: Eligible patients received up to 4 doses tremelimumab (75 mg) given q4 weeks and up to 1 year of durvalumab (1500 mg) given q4 weeks. SBRT at 9 Gy × 3 fractions was given within the first 2 weeks of the start of treatment. Paired biopsies (pretreatment and between 3 and 10 weeks after the first dose of the drug treatment) were done in the medically qualified patients. Major inclusion criteria are metastatic ATC, Eastern Cooperative Oncology Group (ECOG) performance status 0-2, no prior immunotherapy, and last anticancer treatment >7 days before starting the study. The primary endpoint was 1 year OS with the combination of durvalumab, tremelimumab, and SBRT in metastatic ATC patients with a target of 1 year OS in ≥2 out of 12 patients. Results: A total of 13 patients signed consent but only 12 patients ultimately participated in this trial. One patient who consented to the protocol became ineligible for this study due to continued decline in performance status. Patient characteristics were as follows: male (n = 6) with a median age of 71 years (range: 49-82), and ECOG = 1. Nine patients had prior neck radiation and nine patients had prior chemotherapy. Next-generation sequencing and PD-L1 staining were done in the nine patients where tissue was available. High microsatellite instability (MSI) corresponding to mismatch repair defect was noted in two patients. There were zero confirmed responses and only one patient had stable disease and was treated with ≥4 cycles of study drugs. The median time that the patients were under treatment was 11 weeks (1-28 weeks). MSI status did not affect treatment response. High MSI patients were on treatment for 8-14 weeks before disease progression. The median OS was 14.5 weeks with only 1 patient alive beyond 1 year. The presence of a BRAF or p53 mutation did not appear to affect treatment outcome. Conclusions: Tremelimumab and durvalumab with SBRT did not improve OS for ATC. Future research is needed to examine other novel immunotherapy combinations with or without radiotherapy in the treatment of ATC. Clinical Trial Registration: NCT03122496.

YM155 Induces DNA Damage and Cell Death in Anaplastic Thyroid Cancer Cells by Inhibiting DNA Topoisomerase IIα at the ATP-Binding Site

Anaplastic thyroid cancer (ATC) is among the most aggressive of human cancers, and currently there are few effective treatments for most patients. YM155, first identified as a survivin inhibitor, was highlighted in a high-throughput screen performed by the National Cancer Institute, killing ATC cells in vitro and in vivo. However, there was no association between survivin expression and response to YM155 in clinical trials, and YM155 has been mostly abandoned for development despite favorable pharmacokinetic and toxicity profiles. Currently, alternative mechanisms are being explored for YM155 by a number of groups. In this study, ATC patient samples show overexpression of topoisomerase Top2α compared with benign thyroid samples and to differentiated thyroid cancers. ATC cell lines that overexpress Top2α are more sensitive to YM155. We created a YM155-resistant cell line, which shows decreased expression of Top2α and is resensitized with Top2α overexpression. Molecular modeling predicts binding for YM155 in the Top2α ATP-binding site and identifies key amino acids for YM155-Top2α interaction. A Top2α mutant abrogates the effect of YM155, confirming the contribution of Top2α to YM155 mechanism of action. Our results suggest a novel mechanism of action for YM155 and may represent a new therapeutic approach for the treatment of ATC.

Anaplastic thyroid cancer: genome-based search for new targeted therapy options

OBJECTIVE

Anaplastic thyroid cancer (ATC) is one of the most lethal human cancers with meager treatment options. We aimed to identify the targeted drugs already approved by the Food and Drug Administration (FDA) for solid cancer in general, which could be effective in ATC.

DESIGN

Database mining.

METHODS

FDA-approved drugs for targeted therapy were identified by screening the databases of MyCancerGenome and the National Cancer Institute. Drugs were linked to the target genes by querying Drugbank. Subsequently, MyCancerGenome, CIViC, TARGET and OncoKB were mined for genetic alterations which are predicted to lead to drug sensitivity or resistance. We searched the Cancer Genome Atlas database (TCGA) for patients with ATC and probed their sequencing data for genetic alterations which predict a drug response.

RESULTS

In the study,155 FDA-approved drugs with 136 potentially targetable genes were identified. Seventeen (52%) of 33 patients found in TCGA had at least one genetic alteration in targetable genes. The point mutation BRAF V600E was seen in 45% of patients. PIK3CA occurred in 18% of cases. Amplifications of ALK and SRC were detected in 3% of cases, respectively. Fifteen percent of the patients displayed a co-mutation of BRAF and PIK3CA. Besides BRAF-inhibitors, the PIK3CA-inhibitor copanlisib showed a genetically predicted response. The 146 (94%) remaining drugs showed no or low (under 4% cases) genetically predicted drug response.

CONCLUSIONS

While ATC carrying BRAF mutations can benefit from BRAF inhibitors and this effect might be enhanced by a combined strategy including PIK3CA inhibitors in some of the patients, alterations in BRAFWT ATC are not directly targeted by currently FDA-approved options.

In Vitro and In Vivo Effects of the Urokinase Plasminogen Activator Inhibitor WX-340 on Anaplastic Thyroid Cancer Cell Lines

Increased expression of the urokinase-type plasminogen activator (uPA) system is associated with tumor invasion, neo-angiogenesis, and metastatic spread, and has been shown to positively correlate with a poor prognosis in several cancer types, including thyroid carcinomas. In recent years, several uPA inhibitors were found to have anticancer effects in preclinical studies and in some phase II clinical trials, which prompted us to evaluate uPA as a potential therapeutic target for the treatment of patients affected by the most aggressive form of thyroid cancer, the anaplastic thyroid carcinoma (ATC). In this study, we evaluated the in vitro and in vivo effects of WX-340, a highly specific and selective uPA inhibitor, on two ATC-derived cell lines, CAL-62 and BHT-101. The results obtained indicated that WX-340 was able to reduce cell adhesion and invasiveness in a dose-dependent manner in both cell lines. In addition, WX-340 increased uPA receptor (uPAR) protein levels without affecting its plasma membrane concentration. However, this compound was unable to significantly reduce ATC growth in a xenograft model, indicating that uPA inhibition alone may not have the expected therapeutic effects.

Pharmacokinetic Interaction Between the MEK1/MEK2 Inhibitor Trametinib and Oral Contraceptives Containing Norethindrone and Ethinyl Estradiol in Female Patients With Solid Tumors

This phase 1 postapproval study assessed the effect of the mitogen‐activated protein kinase kinase enzyme 1/enzyme 2 inhibitor trametinib (2 mg once daily, repeat dosing) on the pharmacokinetics of combined oral contraceptives (COCs) containing norethindrone (NE; 1 mg daily) and ethinyl estradiol (EE; 0.035 mg daily) in 19 female patients with solid tumors. Compared with NE/EE administered without trametinib, NE/EE administered with steady‐state trametinib was associated with a clinically nonrelevant 20% increase in NE exposure (area under the curve [AUC]) and no effect on EE exposure (geometric mean ratio [geo‐mean] of NE/EE + trametinib to NE/EE [90%CI]: NE AUC calculated to the end of a dosing interval at steady‐state [AUC_tau] 1.20 [1.02‐1.41]; NE AUC from time zero to the last measurable concentration sampling time [AUC_last] 1.2 [0.999‐1.45]; EE AUC_tau 1.06 [0.923‐1.22]; EE AUC_last 1.05 [0.883‐1.25]). Maximum serum concentration (C_max) of NE increased by 13% and C_max of EE decreased by 8.5% when dosed with steady‐state trametinib compared with COCs administered alone (geo‐mean ratio [90%CI]: NE C_max 1.13 [0.933‐1.36]; EE C_max 0.915 [0.803‐1.04]). These results indicate that repeat‐dose trametinib does not lower exposure to NE or EE and, hence, is unlikely to impact the contraceptive efficacy of COCs. The pharmacokinetic parameters of trametinib and its metabolite M5 were consistent with historic data of trametinib alone. Coadministration of trametinib and COCs was generally well tolerated in this study, with observed safety signals consistent with the known safety profile of trametinib and no new reported safety events. Overall, the findings indicate that hormonal COCs can be coadministered in female patients who receive trametinib monotherapy without compromising the contraceptive efficacy.

Pseudo-pheochromocytoma due to obstructive sleep apnea: a case report

SUMMARY

Obstructive sleep apnea (OSA) is a condition of intermittent nocturnal upper airway obstruction. OSA increases sympathetic drive which may result in clinical and biochemical features suggestive of pheochromocytoma. We present the case of a 65-year-old male with a 2.9-cm left adrenal incidentaloma on CT, hypertension, symptoms of headache, anxiety and diaphoresis, and persistently elevated 24-h urine norepinephrine (initially 818 nmol/day (89-470)) and normetanephrine (initially 11.2 µmol/day (0.6-2.7)). He was started on prazosin and underwent left adrenalectomy. Pathology revealed an adrenal corticoadenoma with no evidence of pheochromocytoma. Over the next 2 years, urine norepinephrine and normetanephrine remained significantly elevated with no MIBG avid disease. Years later, he was diagnosed with severe OSA and treated with continuous positive airway pressure. Urine testing done once OSA was well controlled revealed complete normalization of urine norepinephrine and normetanephrine with substantial symptom improvement. It was concluded that the patient never had a pheochromocytoma but rather an adrenal adenoma with biochemistry and symptoms suggestive of pheochromocytoma due to untreated severe OSA. Pseudo-pheochromocytoma is a rare presentation of OSA and should be considered on the differential of elevated urine catecholamines and metanephrines in the right clinical setting.

LEARNING POINTS

Obstructive sleep apnea (OSA) is a common condition among adults. OSA may rarely present as pseudo-pheochromocytoma with symptoms of pallor, palpitations, perspiration, headache, or anxiety. OSA should be considered on the differential of elevated urine catecholamines and metanephrines, especially in patients with negative metaiodobenzylguanidine (MIBG) scan results.

Collision tumor of the thyroid - a challenge during the COVID-19 pandemic

Some of the patients with anaplastic thyroid carcinomas have a coexistent differentiated thyroid cancer, sustaining the hypothesis that this cancer may develop from more differentiated tumors. We describe a case with a collision tumor of the thyroid, defined as a neoplastic lesion composed of two distinct cell populations, with distinct borders. The patient presented during the COVID-19 pandemic with dysphonia, dyspnea, multinodular goiter and a painless, rapidly enlarging, left cervical swelling. She had been first time diagnosed with left nodular goiter in 2007, with an indication for surgery, which she declined. After partial excision of the left latero-cervical adenopathy, the pathological analysis showed massive lymph node metastasis from anaplastic thyroid cancer. A total thyroidectomy was done; the postoperative pathological exam identified a papillary thyroid microcarcinoma in the right lobe and an anaplastic thyroid cancer in the left lobe. Postoperatively, levothyroxine treatment was started and the patient was referred to radiotherapy. This case highlights the importance of urgent management of some cases with compressive multinodular goiter, even during the COVID-19 pandemic.

Combination of Lenvatinib and Pembrolizumab as Salvage Treatment for Paucicellular Variant of Anaplastic Thyroid Cancer: A Case Report

Anaplastic thyroid cancer (ATC) is a rare but aggressive thyroid cancer, responsible for about 50% of all thyroid cancer-related deaths. During the last two decades, the development of a multimodal personalized approach resulted in an increased survival. Here, we present an unusual case of a 54-year old woman with a paucicellular metastatic ATC, a rare variant of ATC, who was treated with a combination of surgery, radiation therapy and cytotoxic chemotherapy. More than two years later, when the disease was rapidly growing, a combination of lenvatinib and pembrolizumab induced a partial tumor response of lung metastasis that persisted over 18 months. Paucicellular ATC may initially show a less aggressive behavior compared to other histological ATC variants. However, over the time, its clinical course can rapidly progress like common ATC. The combination of lenvatinib and pembrolizumab was effective as a salvage therapy for a long period of time.

Bibliometric Insights in Advances of Anaplastic Thyroid Cancer: Research Landscapes, Turning Points, and Global Trends

Background

Thyroid cancers are the most common endocrine malignancies with a dramatic increase in incidences. Anaplastic thyroid cancer is a rare but deadly form among thyroid cancers. To better understand of this field, we assessed the global scientific outputs and tried to depict its overview via bibliometric methods.

Methods

Approximately 1,492 science publications published between 1997 and 2020 were included by systematic retrieval in the WoS database. The general information of them was characterized, and the developmental skeleton and research frontiers were explored.

Results

The article number in this field has been increasing in the past 24 years. North America, East Asia, and Western Europe have reached remarkable achievements. Mutations of BARF and TERT and their downstream pathways have attracted researchers’ attention, where genetic diagnosis provides new clinical insight and several targeted therapeutic approaches have been on the clinical trial.

Conclusions

Numerous efforts have been made to figure out gene expression reprogramming of anaplastic thyroid cancer and key mechanism in driving its dedifferentiation, invasion and migration process. Targeted therapy, immunotherapy, and systematic combination therapy are the recent current research hotspots. These results provide insightful clues for the funding direction and the potential breakthrough direction of the anaplastic thyroid cancer study.

Targeting transcriptional regulators for treatment of anaplastic thyroid cancer

Dysregulation of genes perpetuates cancer progression. During carcinogenesis, cancer cells acquire dependency of aberrant transcriptional programs (known as “transcription addiction”) to meet the high demands for uncontrolled proliferation. The needs for particular transcription programs for cancer growth could be cancer-type-selective. The dependencies of certain transcription regulators could be exploited for therapeutic benefits. Anaplastic thyroid cancer (ATC) is an extremely aggressive human cancer for which new treatment modalities are urgently needed. Its resistance to conventional treatments and the lack of therapeutic options for improving survival might have been attributed to extensive genetic heterogeneity due to subsequent evolving genetic alterations and clonal selections during carcinogenesis. Despite this genetic complexity, mounting evidence has revealed a characteristic transcriptional addiction of ATC cells resulting in evolving diverse oncogenic signaling for cancer cell survival. The transcriptional addiction has presented a huge challenge for effective targeting as shown by the failure of previous targeted therapies. However, an emerging notion is that many different oncogenic signaling pathways activated by multiple upstream driver mutations might ultimately converge on the transcriptional responses, which would provide an opportunity to target transcriptional regulators for treatment of ATC. Here, we review the current understanding of how genetic alterations in cancer distorted the transcription program, leading to acquisition of transcriptional addiction. We also highlight recent findings from studies aiming to exploit the opportunity for targeting transcription regulators as potential therapeutics for ATC.

The prevalence of DNA microsatellite instability in anaplastic thyroid carcinoma - systematic review and discussion of current therapeutic options

INTRODUCTION

Anaplastic thyroid carcinoma is a rare, rapidly progressing, highly aggressive thyroid malignancy. Responses to immune checkpoint inhibitors in mismatch repair-deficient/microsatellite instability-high tumours of other locations have shown promising results, and with the extended approval of the PD-1 receptor inhibitor pembrolizumab by the Food and Drug Administration, also anaplastic thyroid cancer (ATC) requires analysis for microsatellite instability (MSI) status.

MATERIAL AND METHODS

Systematic research for relevant literature was conducted in different databases. Prevalence, detection methods, and the potential prognostic/predictive value of MSI in view of the available targeted therapies were of special focus.

RESULTS

Selected citations revealed the prevalence of MSI in 7.4%, with mutations in the MSH2 gene (33%) being the most frequent, followed by MSH6 (25%) and MLH1 (16.7%) occurring in the following combinations: MLH1-MSH2 (8.3%), MSH2-MSH6 (8.3%), and MLH3-MSH5 (8.3%). No mutations in the PMS2 gene were reported. Sixty-six co-mutations in 9 cases were found, with TP53 (88.9%), NF1 (44.4 %), ATM (33.3%), and RB1 (33.3%) being the most frequent. No RAS mutations were noted. Survival ranged between 2.8 and 48 months, and patient age varied between 49 and 84 years. There are insufficient and heterogenous data concerning the predictive or prognostic value of mismatch repair-deficient/microsatellite instability status.

CONCLUSIONS

Tumour molecular profiling is fundamental in ATC for predictive, prognostic, as well as therapeutic reasons, and analysis of MSI status is strongly suggested because a small subgroup show the MSI signature and might profit from recently approved targeted therapies.

CSPG4 Is a Potential Therapeutic Target in Anaplastic Thyroid Cancer

Background: Anaplastic thyroid cancer (ATC) is a rare cancer with poor prognosis and few treatment options. The objective of this study was to investigate new immune-associated therapeutic targets by identifying ATC-derived, human leukocyte antigen (HLA) class II-presenting peptides. One protein that generated multiple peptides in ATC was chondroitin sulfate-proteoglycan-4 (CSPG4), a transmembrane proteoglycan with increased expression in multiple aggressive cancers, but not yet investigated in ATC. Methods: We applied autologous peripheral blood T cells to ATC patient-derived xenografted mice to examine whether ATC induces a tumor-specific T cell response. We then identified peptide antigens eluted from the HLA-DQ complex in ATC patient-derived cells using mass spectrometry, detecting abundant CSPG4-derived peptides specific to the ATC sample. Next, we analyzed the surface expression level of CSPG4 in thyroid cancer cell lines and primary cell culture using flow cytometry. In addition, we used immunohistochemistry to compare the expression level and localization of the CSPG4 protein in ATC, papillary thyroid cancer, and normal thyroid tissue. We then investigated the correlation between CSPG4 expression and clinicopathological features of patients with thyroid cancer. Results: We found that ATC tissue had a high level of HLA-DQ expression and that the patient's CD4⁺ T cells showed activation when exposed to ATC. By eluting the HLA-DQ complex of ATC tissue, we found that CSPG4 generated one of the most abundant and specific peptides. CSPG4 expression at the cell surface of thyroid cancer was also significantly high when determined by flow cytometry, with the majority of ATC cell lines exhibiting ∼10-fold higher mean fluorescence intensity. Furthermore, most ATC patient cases expressed CSPG4 in the cytoplasm or membrane of the tumor cells. CSPG4 expression was correlated with tumor size, extrathyroidal extension, and intercellular adhesion molecule-1 (ICAM-1) circumferential expression. CSPG4 mRNA overexpression was associated with worse overall survival in patients with ATC and poorly differentiated thyroid cancer. Conclusions: CSPG4 expression is significantly elevated in aggressive thyroid cancers, with a strong correlation with a poor prognosis. The vast number of HLA-DQ eluted CSPG4 peptides was identified in ATC, demonstrating the potential of CSPG4 as a novel immunotherapeutic target for ATC.

Secreted Factors by Anaplastic Thyroid Cancer Cells Induce Tumor-Promoting M2-like Macrophage Polarization through a TIM3-Dependent Mechanism

Simple Summary

Among the different types of thyroid cancer, anaplastic thyroid cancer (ATC) is one of the most aggressive tumors. Characterized for its undifferentiated cells, it spreads quickly to distant organs and does not respond well to standardized therapy. Therefore, there is a critical need to identify new targets that can be translated into therapeutic approaches. ATCs are heavily infiltrated by Tumor-Associated Macrophages (TAMs), and its infiltration density is associated with decreased survival. However, the functional role of TAMs in ATC is still unclear. Our results provide valuable insights into the processes in which soluble factors produced by ATC cells induce M2-like polarization of human monocytes through T cell immunoglobulin and mucin-domain containing protein-3 (TIM3). TIM3 in TAMs should now be further evaluated as a possible potential novel target for treating ATC.

Abstract

Anaplastic thyroid cancer (ATC) is a highly aggressive type of thyroid cancer (TC). Currently, no effective target treatments are available that can improve overall survival, with ATC representing a major clinical challenge because of its remarkable lethality. Tumor-associated macrophages (TAMs) are the most evident cells in ATCs, and their high density is correlated with a poor prognosis. However, the mechanisms of how TAMs promote ATC progression remain poorly characterized. Here, we demonstrated that the treatment of human monocytes (THP-1 cells) with ATC cell-derived conditioned media (CM) promoted macrophage polarization, showing high levels of M2 markers. Furthermore, we found that STAT3 was activated, and this was correlated with an increased expression and secretion of the inflammatory cytokine interleukin-6. Remarkably, the M2-like macrophages obtained revealed tumor-promoting activity. A cytokine array analysis demonstrated that M2-like macrophage-derived CM contained high levels of TIM3, which is an important immune regulatory molecule. Consistently, TIM3 expression was up-regulated in THP-1 cells cultured with ATC cell-derived CM. Moreover, TIM3 blockade significantly reversed the polarization of THP-1 cells induced by ATC cell-secreted soluble factors. We validated the clinical significance of the TIM3 in human TC by analyzing public datasets and found that the expression of TIM3 and its ligand galectin 9 was significantly higher in human TC tissue samples than in normal thyroid tissues. Taken together, our findings identified a new mechanism by which TIM3 induces tumor-promoting M2-like macrophage polarization in TC. Furthermore, TIM3 interference might be a potential tool for treatment of patients with ATC.

Anaplastic Thyroid Cancer Successfully Treated With Radiation and Immunotherapy: A Case Report

Objective

Anaplastic thyroid cancer (ATC) is a rare thyroid cancer subtype with a devastating prognosis. Novel treatment strategies are under investigation to improve the survival of patients with ATC.

Methods

We present a case of recurrent ATC treated with a combination of radiation therapy (RT) and pembrolizumab, a programmed death-1 inhibitor, with a durable complete response.

Results

A 63-year-old woman underwent total thyroidectomy and left neck lymph node dissection and was diagnosed with papillary carcinoma in December, 2017. She received radioiodine in April, 2018. However, a left neck mass was noted in April, 2018 with biopsy demonstrating ATC with 95% positivity for programmed death-ligand 1 immunostaining. Positron emission tomography showed fluorodeoxyglucose uptake in the left thyroid bed and multiple lymph nodes in the left retropharyngeal, left neck, and right upper paratracheal areas. Hypofractionated RT for the recurrent areas was initiated in August,2018, and concomitant pembrolizumab was given 2 days after RT. A total of 10 cycles of pembrolizumab (2 mg/kg) were given every 3 weeks. The computed tomography scan after completion of RT and 3 cycles of pembrolizumab showed shrinkage of the neck lymph nodes. The serial follow-up computed tomography scans showed further shrinkage of the lymph nodes, and there was no recurrence of ATC as of October, 2020.

Conclusion

We describe an ATC case successfully treated with a combination of RT and pembrolizumab with a durable response of 26 months and acceptable toxicities. This result warrants further investigation of this combination regimen in the treatment of ATC.

The prognostic value of lymph node metastasis and the eighth edition of AJCC for patients with anaplastic thyroid cancer

OBJECTIVE

The eighth edition of the American Joint Committee on Cancer (AJCC-v8) for anaplastic thyroid cancer (ATC) made a revision in staging for patients with lymph node metastasis (LNM) based on the seventh edition of AJCC (AJCC-v7). Our study aimed to evaluate the predictive ability of AJCC-v8 for survival in patients with ATC by exploring the association between lymph node stage and prognosis of ATC patients.

METHODS

Retrospective study of ATC in Surveillance, Epidemiology and End Results (SEER) database. The association between LNM and survival of ATC was estimated by the Kaplan-Meier method and Cox regression model. The predictive performances of the AJCC-v8 and AJCC-v7 were estimated through C-index, Akaike information criterion (AIC) and Bayesian information criterion (BIC).

RESULTS

A total of 313 patients with ATC were included in our analysis. Notably, LNM was identified as an independent risk factor for ATC mortality (adjusted HR, 1.47, 95% CI, 1.10-1.96; p = .009), while the risk of mortality in N1a group was comparable to that in N1b group according to univariate (HR, 1.30, 95% CI, 0.92-1.82; p = .133) and multivariate (adjusted HR 0.87, 95% CI, 0.60-1.27; p = .467) cox analyses. Applying the AJCC-v8, the survival of migration population staged T1-3aN1M0 was significantly worse than that of T1-3aN0M0 patients (IVA stage), while was not different from that of T3b-T4bN0/N1M0 patients (IVB stage). With a higher C-index (0.60 vs. 0.59), lower AIC (2728 vs. 2732) and BIC (2732 vs. 2735), AJCC-v8 was demonstrably a more favourable prediction model than AJCC-v7.

CONCLUSIONS

This study demonstrated that LNM was independently associated with poor prognosis of ATC, and AJCC-v8 with the modified staging of patients with LNM showed better survival predictive performance in ATC patients than AJCC-v7.

Piperlongumine, a Potent Anticancer Phytotherapeutic, Induces Cell Cycle Arrest and Apoptosis In Vitro and In Vivo through the ROS/Akt Pathway in Human Thyroid Cancer Cells

Simple Summary

There is no effective treatment currently available for patients with anaplastic, recurrent papillary, or follicular thyroid cancers. Reactive oxygen species (ROS) are believed to hold promise as a new therapeutic strategy for multiple human cancers. However, studies on ROS inducers for human thyroid cancer treatment are scarce. This study assesses the anticancer activity and the detailed downstream mechanisms of piperlongumine, a ROS inducer, in human thyroid cancer cells. We demonstrate that piperlongumine inhibits cell proliferation, regulates the cell cycle, and induces cellular apoptosis in various types of human thyroid cancer cells. The antihuman thyroid cancer activity of piperlongumine was through ROS induction, and it further suppressed the downstream Akt signaling pathway to elevate mitochondria-dependent apoptosis. A mouse xenograft study demonstrated that piperlongumine was safe and could inhibit tumorigenesis in vivo. The present study provides strong evidence that piperlongumine can be used as a therapeutic candidate for human thyroid cancers.

Abstract

Thyroid cancer (TC) is the most common endocrine malignancy, and its global incidence has steadily increased over the past 15 years. TC is broadly divided into well-differentiated, poorly differentiated, and undifferentiated types, depending on the histological and clinical parameters. Thus far, there are no effective treatments for undifferentiated thyroid cancers or advanced and recurrent cancer. Therefore, the development of an effective therapeutic is urgently needed for such patients. Piperlongumine (PL) is a naturally occurring small molecule derived from long pepper; it is selectively toxic to cancer cells by generating reactive oxygen species (ROS). In this study, we demonstrate the potential anticancer activity of PL in four TC cell lines. For this purpose, we cultured TC cell lines and analyzed the following parameters: Cell viability, colony formation, cell cycle, apoptosis, and cellular ROS induction. PL modulated the cell cycle, induced apoptosis, and suppressed tumorigenesis in TC cell lines in a dose- and time-dependent manner through ROS induction. Meanwhile, an intrinsic caspase-dependent apoptosis pathway was observed in the TC cells under PL treatment. The activation of Erk and the suppression of the Akt/mTOR pathways through ROS induction were seen in cells treated with PL. PL-mediated apoptosis in TC cells was through the ROS-Akt pathway. Finally, the anticancer effect and safety of PL were also demonstrated in vivo. Our findings indicate that PL exhibits antitumor activity and has the potential for use as a chemotherapeutic agent against TC. This is the first study to show the sensitivity of TC cell lines to PL.

Nanoparticles: Promising Auxiliary Agents for Diagnosis and Therapy of Thyroid Cancers

Simple Summary

Thyroid cancer (TC) is rare relative to cancers of many other organs (breast, prostate, lung, and colon). The majority of TCs are differentiated tumors that are relatively easy to treat and have a good prognosis. However, for anaplastic TC, a rapidly growing and aggressive tumor, treatment is suboptimal because the effective drugs cause severe adverse effects. Drug delivery by nanocarriers can improve treatment by reducing side effects. This can either be mediated through better retention in the tumor tissue due to size (passive targeting) or through the attachment of specific molecules that zero in on the cancer cells (active targeting). Nanoparticles are already used for diagnosis and imaging of TC. For unresectable anaplastic TC, nanoparticle-based treatments, less suitable for deeply located cancers, could be useful, based on low-intensity focused ultrasound and near-infrared irradiation. All potential applications of nanoparticles in TC are still in the preclinical phase.

Abstract

Cancers of the endocrine system are rare. The majority are not highly malignant tumors. Thyroid cancer (TC) is the most common endocrine cancer, with differentiated papillary and follicular tumors occurring more frequently than the more aggressive poorly differentiated and anaplastic TC. Nanoparticles (NP) (mainly mesoporous silica, gold, carbon, or liposomes) have been developed to improve the detection of biomarkers and routine laboratory parameters (e.g., thyroid stimulating hormone, thyroglobulin, and calcitonin), tumor imaging, and drug delivery in TC. The majority of drug-loaded nanocarriers to be used for treatment was developed for anaplastic tumors because current treatments are suboptimal. Further, doxorubicin, sorafenib, and gemcitabine treatment can be improved by nanotherapy due to decreased adverse effects. Selective delivery of retinoic acid to TC cells might improve the re-differentiation of de-differentiated TC. The use of carbon NPs for the prevention of parathyroid damage during TC surgery does not show a clear benefit. Certain technologies less suitable for the treatment of deeply located cancers may have some potential for unresectable anaplastic carcinomas, namely those based on low-intensity focused ultrasound and near-infrared irradiation. Although some of these approaches yielded promising results in animal studies, results from clinical trials are currently lacking.

Effects of Dihydrotanshinone I on Proliferation and Invasiveness of Paclitaxel-Resistant Anaplastic Thyroid Cancer Cells

ATC is a very rare, but extremely aggressive form of thyroid malignancy, responsible for the highest mortality rate registered for thyroid cancer. In patients without known genetic aberrations, the current treatment is still represented by palliative surgery and systemic mono- or combined chemotherapy, which is often not fully effective for the appearance of drug resistance. Comprehension of the mechanisms involved in the development of the resistance is therefore an urgent issue to suggest novel therapeutic approaches for this very aggressive malignancy. In this study, we created a model of anaplastic thyroid cancer (ATC) cells resistant to paclitaxel and investigated the characteristics of these cells by analyzing the profile of gene expression and comparing it with that of paclitaxel-sensitive original ATC cell lines. In addition, we evaluated the effects of Dihydrotanshinone I (DHT) on the viability and invasiveness of paclitaxel-resistant cells. ATC paclitaxel-resistant cells highlighted an overexpression of ABCB1 and a hyper-activation of the NF-κB compared to sensitive cells. DHT treatment resulted in a reduction of viability and clonogenic ability of resistant cells. Moreover, DHT induces a decrement of NF-κB activity in SW1736-PTX and 8505C-PTX cells. In conclusion, to the best of our knowledge, the results of the present study are the first to demonstrate the antitumor effects of DHT on ATC cells resistant to Paclitaxel in vitro.

Targeting the Highly Expressed microRNA miR-146b with CRISPR/Cas9n Gene Editing System in Thyroid Cancer

Thyroid cancer is the most common endocrine malignancy, and the characterization of the genetic alterations in coding-genes that drive thyroid cancer are well consolidated in MAPK signaling. In the context of non-coding RNAs, microRNAs (miRNAs) are small non-coding RNAs that, when deregulated, cooperate to promote tumorigenesis by targeting mRNAs, many of which are proto-oncogenes and tumor suppressors. In thyroid cancer, miR-146b-5p is the most overexpressed miRNA associated with tumor aggressiveness and progression, while the antisense blocking of miR-146b-5p results in anti-tumoral effect. Therefore, inactivating miR-146b has been considered as a promising strategy in thyroid cancer therapy. Here, we applied the CRISPR/Cas9n editing system to target the MIR146B gene in an aggressive anaplastic thyroid cancer (ATC) cell line. For that, we designed two single-guide RNAs cloned into plasmids to direct Cas9 nickase (Cas9n) to the genomic region of the pre-mir-146b structure to target miR-146b-5p and miR-146b-3p sequences. In this plasmidial strategy, we cotransfected pSp-Cas9n-miR-146b-GuideA-puromycin and pSp-Cas9n-miR-146b-GuideB-GFP plasmids in KTC2 cells and selected the puromycin resistant + GFP positive clones (KTC2-Cl). As a result, we observed that the ATC cell line KTC2-Cl1 showed a 60% decrease in the expression of miR-146b-5p compared to the control, also showing reduced cell viability, migration, colony formation, and blockage of tumor development in immunocompromised mice. The analysis of the MIR146B edited sequence shows a 5 nt deletion in the miR-146b-5p region and a 1 nt deletion in the miR-146b-3p region in KTC2-Cl1. Thus, we developed an effective CRISPR/Cas9n system to edit the MIR146B miRNA gene and reduce miR-146b-5p expression which constitutes a potential molecular tool for the investigation of miRNAs function in thyroid cancer.

Opportunities and Challenges of Liquid Biopsy in Thyroid Cancer

Thyroid cancer is the most common malignancy of the endocrine system, encompassing different entities with distinct histological features and clinical behavior. The diagnostic definition, therapeutic approach, and follow-up of thyroid cancers display some controversial aspects that represent unmet medical needs. Liquid biopsy is a non-invasive approach that detects and analyzes biological samples released from the tumor into the bloodstream. With the use of different technologies, tumor cells, free nucleic acids, and extracellular vesicles can be retrieved in the serum of cancer patients and valuable molecular information can be obtained. Recently, a growing body of evidence is accumulating concerning the use of liquid biopsy in thyroid cancer, as it can be exploited to define a patient's diagnosis, estimate their prognosis, and monitor tumor recurrence or treatment response. Indeed, liquid biopsy can be a valuable tool to overcome the limits of conventional management of thyroid malignancies. In this review, we summarize currently available data about liquid biopsy in differentiated, poorly differentiated/anaplastic, and medullary thyroid cancer, focusing on circulating tumor cells, circulating free nucleic acids, and extracellular vesicles.

Combination of Lenvatinib and Pembrolizumab Is an Effective Treatment Option for Anaplastic and Poorly Differentiated Thyroid Carcinoma

Background: Anaplastic thyroid carcinoma (ATC) and metastatic poorly differentiated thyroid carcinomas (PDTCs) are rare aggressive malignancies with poor overall survival (OS) despite extensive multimodal therapy. These tumors are highly proliferative, with frequently increased tumor mutational burden (TMB) compared with differentiated thyroid carcinomas, and elevated programmed death ligand 1 (PD-L1) levels. These tumor properties implicate responsiveness to antiangiogenic and antiproliferative multikinase inhibitors such as lenvatinib, and immune checkpoint inhibitors such as pembrolizumab. Patients and Methods: In a retrospective study, we analyzed six patients with metastatic ATC and two patients with PDTC, who received a combination therapy of lenvatinib and pembrolizumab. Lenvatinib was started at 14-24 mg daily and combined with pembrolizumab at a fixed dose of 200 mg every three weeks. Maximum treatment duration with this combination was 40 months, and 3 of 6 ATC patients are still on therapy. Patient tumors were characterized by whole-exome sequencing and PD-L1 expression levels (tumor proportion score [TPS] 1-90%). Results: Best overall response (BOR) within ATCs was 66% complete remissions (4/6 CR), 16% stable disease (1/6 SD), and 16% progressive disease (1/6 PD). BOR within PDTCs was partial remission (PR 2/2). The median progression-free survival was 17.75 months for all patients, and 16.5 months for ATCs, with treatment durations ranging from 1 to 40 months (1, 4, 11, 15, 19, 25, 27, and 40 months). Grade III/IV toxicities developed in 4 of 8 patients, requiring dose reduction/discontinuation of lenvatinib. The median OS was 18.5 months, with three ATC patients being still alive without relapse (40, 27, and 19 months) despite metastatic disease at the time of treatment initiation (UICC and stage IVC). All patients with long-term (>2 years) or complete responses (CRs) had either increased TMB or a PD-L1 TPS >50%. Conclusions: Our results implicate that the combination of lenvatinib and pembrolizumab might be safe and effective in patients with ATC/PDTC and can result in complete and long-term remissions. The combination treatment is now being systematically examined in a phase II clinical trial (Anaplastic Thyroid Carcinoma Lenvatinib Pembrolizumab [ATLEP]) in ATC/PDTC patients.