Anaplastic Thyroid Cancer Therapy Research Articles

Patterns of loco-regional progression and patient outcomes after definitive-dose radiation therapy for anaplastic thyroid cancer

Patterns of loco-regional progression and patient outcomes after definitive-dose radiation therapy for anaplastic thyroid cancer

228 Adjuvant radiation therapy for anaplastic thyroid cancer: single center experience of 12 patients with advanced and not completely resected disease: toxicity and treatment complications

228 Adjuvant radiation therapy for anaplastic thyroid cancer: single center experience of 12 patients with advanced and not completely resected disease: toxicity and treatment complications

Nanoclay Drug-Delivery System Loading Potassium Iodide Promotes Endocytosis and Targeted Therapy in Anaplastic Thyroid Cancer.

The rapid proliferative biological behavior of primary foci of anaplastic thyroid cancer (ATC) makes it a lethal tumor. According to the specific iodine uptake capacity of thyroid cells and enhanced endocytosis of ATC cells, we designed a kind of nanoclay drug-loading system and showed a promising treatment strategy for ATC. Introducing potassium iodide (KI) improves the homoaggregation of clay nanoparticles and then affects the distribution of nanoparticles in vivo, which makes KI@DOX-KaolinMeOH enriched almost exclusively in thyroid tissue. Simultaneously, the improvement of dispersibility of KI@DOX-KaolinMeOH changes the target uptake of ATC cells by improving the endocytosis and nanoparticle-induced autophagy, which regulate the production of autolysosomes and autophagy-enhanced chemotherapy, eventually contributing to a tumor inhibition rate of more than 90% in the primary foci of ATC. Therefore, this facile strategy to improve the homoaggregation of nanoclay by introducing KI has the potential to become an advanced drug delivery vehicle in ATC treatment.

Abstract 5505: Combination nitazoxanide and auranofin treatment has synergistic anticancer activity in anaplastic thyroid cancer and act by enhanced activation of multiple cell death pathways

Abstract Purpose: Anaplastic thyroid cancer (ATC) is one of the most aggressive human cancers, with a median survival time of 6 months and with no current curative treatment. We have used quantitative high-throughput screening (qHTS) of clinically approved or investigational agents to identify candidate compounds for ATC therapy. As monotherapy for most cancers is not effective, we used combination drug matrix screening of highly active compounds from our single agent qHTS to identify compound combinations that may show synergistic effect. In this study, we evaluated the anticancer activity of nitazoxanide and auranofin combination treatment and its mechanism of action and biomarkers of treatment response in in vitro and in vivo models of ATC. Experimental Design: We used four (8505C, C643, SW1736, THJ16T) ATC cell lines in in vitro and in vivo ATC models to evaluate the safety and efficacy of this combination treatment compared to single agent and vehicle control. Results: Combination nitazoxanide and auranofin treatment synergistically inhibited cellular proliferation (p<0.001) and inhibited colony formation and migration (p<0.001) in ATC cell lines. We observed cellular oxidative stress with significant increase in ROS levels in the combination treatment group (p<0.001). Nitazoxanide treatment alone and in combination with auranofin caused G1/G0 arrest in cell cycle, induced autophagy (increased LC3BII expression) and later apoptosis. Auranofin treatment alone and in combination with nitazoxanide induced ferroptosis (decreased GPX4 expression and intracellular GSH/GSSG ratios). RNA-Seq analysis, to identify biomarkers of response, showed >7-fold increase in HMOX-1 (heme oxygenase 1) with combination treatment which was validated by western blot. Combination treatment significantly inhibited tumor growth as compared to single agents (p<0.01) and had no significant treatment-related toxicity in vivo. Analysis of tumor samples showed significantly increased LC3BII expression by immunohistochemistry and reduced GPX4 mRNA expression (p<0.0001) with combination treatment compared to control in vivo. Conclusions: Combination nitazoxanide and auranofin treatment has synergistic anticancer activity in both in vitro and in vivo ATC models. The synergistic activity of the combination is due to enhanced G1/G0 arrest, greater activation of autophagy, apoptosis and ferroptosis than single drug treatment. LC3BII, HMOX-1 and GPX4 levels could be useful biomarkers of treatment response to combination nitazoxanide and auranofin. Citation Format: Chandrayee Ghosh, Viswanath Gunda, Jiangnan Hu, Lisa Zhang, Ya-Qin Zhang, Min Shen, Electron Kebebew. Combination nitazoxanide and auranofin treatment has synergistic anticancer activity in anaplastic thyroid cancer and act by enhanced activation of multiple cell death pathways. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5505.

Targeted therapy of anaplastic thyroid cancer

Introduction. Anaplastic thyroid cancer (ATC) is a very rare malignant tumor of the thyroid comprising 1–2 % of all thyroid cancers. In this pathology, response rate for standard systemic therapy is less than 15 %, and long-term results remain unsatisfactory. Additionally, there are no data conclusively showing that cytotoxic chemotherapy improves survival or quality of life in patients with ATC.Aim. To improve the results of treatment of patients with ATC through evaluation of the effectiveness of targeted therapy in cases of BRAFV600E mutation.Materials and methods. The multicenter prospective study included 29 patients with ATC IVB–C, T4a–bN1a–bM0–1. The patients were divided into 2 groups. The Group 1 (control) included 15 patients with resectable / nonresectable, metastatic / nonmetastatic ATC (without BRAFV600E mutation), stages IVB–C who received standard types of treatment (surgical intervention, radiation, and chemotherapy). The Group 2 consisted of 14 patients with nonresectable or metastatic ATC, stages IVB–C, who received combination therapy (surgical intervention, radiation, and chemotherapy) with inclusion of inhibitors of BRAF dabrafenib and trametinib in neoadjuvant and adjuvant regimens.Results. The study showed the effectiveness of targeted therapy with inhibitors of BRAF mutations in treatment of locally advanced non-operable metastatic ATC with BRAFV600E mutation. Overall response (complete response + partial response) in the Group 1 was 0 %, in the Group 2 it was 64 %. Therefore, treatment scheme dabrafenib + trametinib is a prmising approach to combination targeted therapy in patients with ATC and BRAFV600E mutation. Conclusion. Dabrafenib + trametinib is a promising combination targeted therapy option for patients with ATC with a BRAFV600 mutation demonstrates a high overall response rate, a prolonged duration of response, and an increase in survival rates with controlled toxicity.

Synthesis of lenvatinib-loaded upconversion@polydopamine nanocomposites for upconversion luminescence imaging-guided chemo-photothermal synergistic therapy of anaplastic thyroid cancer.

Anaplastic thyroid cancer (ATC) is the most malignant and aggressive of all classifications of thyroid cancer. ATC normally has poor prognosis after classic treatments such as surgery, endocrine therapy, radiotherapy and chemotherapy. Herein, a novel nanocomposite (named as UCNP@PDA@LEN) has been synthesized for chemo-photothermal therapy of ATC, which is based on a NaErF4:Tm3+@NaYbF4@NaYF4:Nd3+ upconverting nanoparticle (UCNP) as the core, a near-infrared light (NIR)-absorbing polydopamine (PDA) as the shell, and lenvatinib (LEN) as a chemotherapeutic drug. The as-prepared multifunctional UCNP@PDA@LEN exhibits excellent photothermal conversion capability (η = 30.7%), good photothermal stability and reasonable biocompatibility. Owing to the high UCL emission and good tumor accumulation ability, the UCL imaging of mouse-bearing ATC (i.e., C643 tumor) has been achieved by UCNP@PDA@LEN. Under 808 nm NIR laser irradiation, the UCNP@PDA@LEN shows a synergistic interaction between photothermal therapy (PTT) and chemotherapy (CT), resulting in strongly suppressed mouse-bearing C643 tumor. The results provide an explicit approach for developing theranostics with high anti-ATC efficiency.

Lipid-Peptide-mRNA Nanoparticles Augment Radioiodine Uptake in Anaplastic Thyroid Cancer.

Restoring sodium iodide symporter (NIS) expression and function remains a major challenge for radioiodine therapy in anaplastic thyroid cancer (ATC). For more efficient delivery of messenger RNA (mRNA) to manipulate protein expression, a lipid-peptide-mRNA (LPm) nanoparticle (NP) is developed. The LPm NP is prepared by using amphiphilic peptides to assemble a peptide core and which is then coated with cationic lipids. An amphiphilic chimeric peptide, consisting of nine arginine and hydrophobic segments (6 histidine, C18 or cholesterol), is synthesized for adsorption of mRNA encoding NIS in RNase-free conditions. In vitro studies show that LP(R9H6) m NP is most efficient at delivering mRNA and can increase NIS expression in ATC cells by more than 10-fold. After intratumoral injection of NIS mRNA formulated in optimized LPm NP, NIS expression in subcutaneous ATC tumor tissue increases significantly in nude mice, resulting in more iodine 131 (131 I) accumulation in the tumor, thereby significantly inhibiting tumor growth. Overall, this work designs three arginine-rich peptide nanoparticles, contributing to the choice of liposome cores for gene delivery. LPm NP can serve as a promising adjunctive therapy for patients with ATC by restoring iodine affinity and enhancing the therapeutic efficacy of radioactive iodine.

Radionuclide 131I-labeled albumin-indocyanine green nanoparticles for synergistic combined radio-photothermal therapy of anaplastic thyroid cancer.

ObjectivesAnaplastic thyroid cancer (ATC) cells cannot retain the radionuclide iodine 131 (131I) for treatment due to the inability to uptake iodine. This study investigated the feasibility of combining radionuclides with photothermal agents in the diagnosis and treatment of ATC.Methods 131I was labeled on human serum albumin (HSA) by the standard chloramine T method. 131I-HSA and indocyanine green (ICG) were non-covalently bound by a simple stirring to obtain 131I-HSA-ICG nanoparticles. Characterizations were performed in vitro. The cytotoxicity and imaging ability were investigated by cell/in vivo experiments. The radio-photothermal therapy efficacy of the nanoparticles was evaluated at the cellular and in vivo levels.ResultsThe synthesized nanoparticles had a suitable size (25–45 nm) and objective biosafety. Under the irradiation of near-IR light, the photothermal conversion efficiency of the nanoparticles could reach 24.25%. In vivo fluorescence imaging and single-photon emission CT (SPECT)/CT imaging in small animals confirmed that I-HSA-ICG/131I-HSA-ICG nanoparticles could stay in tumor tissues for 4–6 days. Compared with other control groups, 131I-HSA-ICG nanoparticles had the most significant ablation effect on tumor cells under the irradiation of an 808-nm laser.ConclusionsIn summary, 131I-HSA-ICG nanoparticles could successfully perform dual-modality imaging and treatment of ATC, which provides a new direction for the future treatment of iodine-refractory thyroid cancer.

Anticancer effects of natural phytochemicals in anaplastic thyroid cancer (Review).

Anaplastic thyroid cancer (ATC) is an aggressive and lethal malignancy having a dismal prognosis. Phytochemicals are bioactive components obtained from plants that have been proven useful to treat numerous diseases. Phytochemicals are also an important source of novel anticancer drugs and an important area of research due to the numerous available candidates that can potentially treat cancers. This review discusses naturally occurring phytochemicals and their derivatives that show promising anticancer effects in anaplastic thyroid cancer. Anticancer effects include cell growth inhibition, induction of apoptosis, promoting cell cycle arrest, suppressing angiogenesis, modulating autophagy, and increasing the production of reactive oxygen species. Phytochemicals are not only prospective candidates in the therapy of anaplastic thyroid cancer but also exhibit potential as adjuvants to improve the anticancer effects of other drugs. Although some phytochemicals have excellent anticancer properties, drug resistance observed during the use of resveratrol and artemisinin in different anaplastic thyroid cancer cell lines is still a problem. Anaplastic thyroid cancer cells have several biological, clinical, and drug-resistance features that differ from differentiated thyroid cancer cells. Phytochemicals such as resveratrol and quercetin exhibit different biological effects in anaplastic thyroid cancer and differentiated thyroid cancer. Tumor cells depend on increased aerobic glycolysis by mitochondrial oxidative phosphorylation to provide energy for their rapid growth, invasiveness, and drug resistance. Phytochemicals can alter signaling cascades, modulate the metabolic properties of cancer cells, and influence the mitochondrial membrane potential of anaplastic thyroid cancer cells. These findings enrich our knowledge of the anticancer effects of phytochemicals and highlight alternative therapies to prevent drug resistance in anaplastic thyroid cancer.

Radio(chemo)therapy in anaplastic thyroid cancer—high locoregional but low distant control rates—a monocentric analysis of a tertiary referral center

BackgroundAnaplastic thyroid cancer (ATC) is a lethal disease with highly aggressive disease progression. This study analyses the influence of radio(chemo)therapy, R(C)T, on disease control, survival rates and predictors for survival.Patients and methodsA total of 33 patients with ATC, treated at a tertiary referral center between May 2001 and April 2020 were included. Univariate and multivariate analysis were used to investigate correlates of R(C)T and predictors on disease control and survival rates.ResultsMedian follow-up was 4 months. In UICC stage IVA and IVB median overall survival (OS) was 8 months, median progression-free survival (PFS) was 6 months. Patients with UICC stage IVA and IVB and patients being irradiated with a radiation dose of more than 60 Gy showed increased OS. Of these patients, 3 were alive and free from disease. All of them receiving cisplatin-based radiochemotherapy and a minimum radiation dose of 66 Gy. UICC stage IVC showed a median OS of 2.5 months and a median PFS of 1 month. Only 2 of 16 patients had local failure.ConclusionDepending on UICC stage, RT with high radiation dose can lead to improved OS or at least higher locoregional control. A limiting factor is the high incidence of distant metastases; therefore modern systemic treatment options should be integrated into multimodal therapy concepts.

USP26 promotes anaplastic thyroid cancer progression by stabilizing TAZ

Anaplastic thyroid cancer (ATC) is one of the most lethal and aggressive human malignancies, with no effective treatment currently available. The Hippo tumor suppressor pathway is highly conserved in mammals and plays an important role in carcinogenesis. TAZ is one of major key effectors of the Hippo pathway. However, the mechanism supporting abnormal TAZ expression in ATC remains to be characterized. In the present study, we identified USP26, a DUB enzyme in the ubiquitin-specific proteases family, as a bona fide deubiquitylase of TAZ in ATC. USP26 was shown to interact with, deubiquitylate, and stabilize TAZ in a deubiquitylation activity-dependent manner. USP26 depletion significantly decreased ATC cell proliferation, migration, and invasion. The effects induced by USP26 depletion could be rescued by further TAZ overexpression. Depletion of USP26 decreased the TAZ protein level and the expression of TAZ/TEAD target genes in ATC, including CTGF, ANKRD1, and CYR61. In general, our findings establish a previously undocumented catalytic role for USP26 as a deubiquitinating enzyme of TAZ and provides a possible target for the therapy of ATC.

An in situ spontaneously forming micelle-hydrogel system with programmable release for the sequential therapy of anaplastic thyroid cancer.

Anaplastic thyroid carcinoma (ATC) is a lethal malignancy with a 1 year survival rate of less than 20%. Combination chemotherapy with cisplatin and paclitaxel is recommended as a critical therapeutic approach toward ATC. However, harsh side-effects on patients and unsatisfactory intratumoral concentrations hamper the effectiveness of systemic chemotherapy. In this work, an in situ spontaneously forming micelle-hydrogel system (iMHS) with programmable-release characteristics was developed for sequential chemotherapy. Taking advantage of the diffusion rate of the hydrophobic drug in the micellar network and the degradation of the hydrogel matrix, iMHS supported sequential chemotherapy via programmatic release. Moreover, in vitro and in vivo studies demonstrated the superiority of sequential release from iMHS over other approaches, regardless of the genetic profile (e.g., different BRAF, TP53, and TERT promoter mutations, etc.). Additionally, iMHS presented the significant ability to prevent local tumor recurrence in a post-surgical model. Overall, iMHS may serve as a promising strategy for the enhanced localized treatment of ATC via the programmable release of chemotherapy drugs with implied translational value.

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

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. 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. To conclude, our findings demonstrate novel therapeutic targets and treatment strategies for undifferentiated ATC.

Augmentation of lenvatinib efficacy by topical treatment of miR-634 ointment in anaplastic thyroid cancer

Anaplastic thyroid cancer (ATC) is one of the most lethal types of human tumors. Lenvatinib can improve the disease control and prognosis in patients with ATC. However, there is an unmet need to develop a therapeutically safer and non-invasive strategy that improves the efficacy of lenvatinib for advanced ATC tumors, which grow larger close to the skin. We previously demonstrated that the topical application of an ointment incorporating tumor suppressive microRNA (TS-miR), miR-634, is a useful strategy as a TS-miR therapeutics. Here, we found that the overexpression of miR-634 synergistically increased lenvatinib-induced cytotoxicity by concurrently downregulating multiple genes related to cytoprotective processes, including ASCT2, a glutamine transporter, in ATC cell lines. Furthermore, the topical application of a miR-634 ointment on subcutaneous tumors effectively augmented the anti-tumor effects of lenvatinib in an ATC xenograft mouse model. Thus, we propose topical treatment of a miR-634 ointment as a rational strategy for improving lenvatinib-based therapy for ATC.

Vitamin C induces ferroptosis in anaplastic thyroid cancer cells by ferritinophagy activation

Anaplastic thyroid cancer (ATC) is a rare but highly lethal disease. So far, there is no available established treatment which can prolong its survival. In this regard, effective therapies are urgently needed. Vitamin C widely serves as an anti-cancer agent. However, the potential effects of vitamin C against thyroid tumorigenesis remained unclear. The present study demonstrated that vitamin C could significantly inhibit ATC cells growth through ferroptosis activation, evidenced by the GPX4 inactivation, ROS accumulation and iron-dependent lipid peroxidation. Our results demonstrated that vitamin C treatment induced ferritinophagy and subsequent degradation of ferritin, leading to the release of free iron. Excessive iron further triggered ROS generation via Fenton reaction. The positive feedback mediated by ROS and iron sustained lipid peroxidation and further resulted in ferroptosis of ATC cells. The better understanding of the anti-cancer mechanisms of vitamin C provides a potential strategy for ATC therapy.

Tunicamycin as a Novel Redifferentiation Agent in Radioiodine Therapy for Anaplastic Thyroid Cancer.

The silencing of thyroid-related genes presents difficulties in radioiodine therapy for anaplastic thyroid cancers (ATCs). Tunicamycin (TM), an N-linked glycosylation inhibitor, is an anticancer drug. Herein, we investigated TM-induced restoration of responsiveness to radioiodine therapy in radioiodine refractory ATCs. 125I uptake increased in TM-treated ATC cell lines, including BHT101 and CAL62, which was inhibited by KClO4, a sodium-iodide symporter (NIS) inhibitor. TM upregulated the mRNA expression of iodide-handling genes and the protein expression of NIS. TM blocked pERK1/2 phosphorylation in both cell lines, but AKT (protein kinase B) phosphorylation was only observed in CAL62 cells. The downregulation of glucose transporter 1 protein was confirmed in TM-treated cells, with a significant reduction in 18F-fluorodeoxyglucose (FDG) uptake. A significant reduction in colony-forming ability and marked tumor growth inhibition were observed in the combination group. TM was revealed to possess a novel function as a redifferentiation inducer in ATC as it induces the restoration of iodide-handling gene expression and radioiodine avidity, thereby facilitating effective radioiodine therapy.

Disruption of Cell-Cell Communication in Anaplastic Thyroid Cancer as an Immunotherapeutic Opportunity.

Thyroid cancer incidence is increasing at an alarming rate, almost tripling every decade. About 44,280 new cases of thyroid cancer (12,150 in men and 32,130 in women) are estimated to be diagnosed in 2021, with an estimated death toll of around 2200. Although most thyroid tumors are treatable and associated with a favorable outcome, anaplastic thyroid cancer (ATC) is extremely aggressive with a grim prognosis of 6-9months post-diagnosis. A large contributing factor to this aggressive nature is that ATC is completely refractory to mainstream therapies. Analysis of the tumor microenvironment (TME) associated with ATC can relay insight to the pathological realm that encompasses tumors and aids in cancer progression and proliferation. The TME is defined as a complex niche that surrounds a tumor and involves a plethora of cellular components whose secretions can modulate the environment in order to favor tumor progression. The cellular heterogeneity of the TME contributes to its dynamic function due to the presence of both immune and nonimmune resident, infiltrating, and interacting cell types. Associated immune cells discussed in this chapter include macrophages, dendritic cells (DCs), natural killer (NK) cells, and tumor-infiltrating lymphocytes (TILs). Nonimmune cells also play a role in the establishment and proliferation of the TME, including neuroendocrine (NE) cells, adipocytes, endothelial cells (ECs), mesenchymal stem cells (MSCs), and fibroblasts. The dynamic nature of the TME contributes greatly to cancer progression.Recent work has found ATC tissues to be defined by a T cell-inflamed "hot" tumor immune microenvironment (TIME) as evidenced by presence of CD3+ and CD8+ T cells. These tumor types are amenable to immune checkpoint blockade (ICB) therapy. This therapeutic avenue, as of 2021, has remained unexplored in ATC. New studies should seek to explore the therapeutic feasibility of a combination therapy, through the use of a small molecule inhibitor with ICB in ATC. Screening of in vitro model systems representative of papillary, anaplastic, and follicular thyroid cancer explored the expression of 29 immune checkpoint molecules. There are higher expressions of HVEM, BTLA, and CD160 in ATC cell lines when compared to the other TC subtypes. The expression level of HVEM was more than 30-fold higher in ATC compared to the others, on average. HVEM is a member of tumor necrosis factor (TNF) receptor superfamily, which acts as a bidirectional switch through interaction with BTLA, CD160, and LIGHT, in a cis or trans manner. Given the T cell-inflamed hot TIME in ATC, expression of HVEM on tumor cells was suggestive of a possibility for complex crosstalk of HVEM with inflammatory cytokines. Altogether, there is emerging evidence of a T cell-inflamed TIME in ATC along with the expression of immune checkpoint proteins HVEM, BTLA, and CD160 in ATC. This can open doors for combination therapies using small molecule inhibitors targeting downstream effectors of MAPK pathway and antagonistic antibodies targeting the HVEM/BTLA axis as a potentially viable therapeutic avenue for ATC patients. With this being stated, the development of adaptive resistance to targeted therapies is inevitable; therefore, using a combination therapy that targets the TIME can serve as a preemptive tactic against the characteristic therapeutic resistance that is seen in ATC. The dynamic nature of the TME, including the immune cells, nonimmune cells, and acellular components, can serve as viable targets for combination therapy in ATC. Understanding the complex interactions of these associated cells and the paradigm in which their secretions and components can serve as immunomodulators are critical points of understanding when trying to develop therapeutics specifically tailored for the anaplastic thyroid carcinoma microenvironment.

Synthesis and characterization of CD133 targeted aptamer-drug conjugates for precision therapy of anaplastic thyroid cancer.

Anaplastic thyroid cancer (ATC) is an undifferentiated and highly aggressive type of thyroid cancer and is extremely resistant to standard therapies such as surgical resection and radioactive iodine therapy. Although targeted therapeutic agents including small molecule drugs and monoclonal antibodies are rapidly developed in recent years, no ATC targeted drugs are available to date; thereby, novel targeted therapies are needed to improve the outcomes of ATC patients. Aptamers are single-stranded DNA (or RNA) molecules that can selectively bind to cancer specific antigens, and aptamer-based targeted therapy has certain advantages over that based on antibodies due to its high binding affinity and low immunogenicity. Here, we identified that CD133, a cancer stem cell marker, was specifically expressed in ATC tumor tissues and cells, implying that CD133 is a potential drug target for ATC therapy. Additionally, we successfully obtained a CD133 targeted aptamer AP-1 by paired cell-based SELEX, which can precisely recognize CD133 antigen in vitro. Furthermore, the truncated AP-1-M aptamer from its precursor AP-1 has shown higher binding affinity for CD133, and specifically accumulated in anaplastic thyroid cancer FRO cell derived tumor in vivo. Conjugation of truncated AP-1-M with doxorubicin could dramatically inhibit CD133 positive FRO cell proliferation, induce cell apoptosis in vitro, and also suppress tumor growth in FRO cell xenograft mice in vivo. Our results clearly demonstrated that the CD133 targeted aptamer AP-1-M conjugated with anticancer drugs has potential to become a promising therapeutic approach against ATC in the near future.

Treatment of anaplastic thyroid cancer with tyrosine kinase inhibitors targeted on the tumor vasculature: initial experience in clinical practice.

Anaplastic thyroid cancer (ATC) is a rarely occurring refractory disease. While recent clinical trials have demonstrated the efficacy of tyrosine kinase inhibitor (TKI) therapy for ATC, evidence is scarce in clinical practice. In this study, we reviewed our initial experiences with TKI treatment in ATC patients with the aim of revealing the efficacy and safety of the same in clinical practice. We retrospectively reviewed our experiences with TKI treatment use in ATC patients diagnosed at our institute from 2014 to 2019. Changes in the patients' neutrophil-to-lymphocyte ratio (NLR) by TKI therapy introduction as well as their clinical factors to indicate the efficacy were examined. Seven patients showed no indication for TKI treatment, while 13 (65%) received treatment. The median duration of TKI treatment was 1.9 months. All patients died, and the overall survival period from diagnosis was 4.7 (95% confidence interval: 2.0-11.5) months. Adverse events ≥Grade 3 were observed commonly (92.3%), and resulted in the termination of TKI treatment in six cases (46.1%). Existence of multiple unfavorable characteristics (higher Prognostic Index) was associated with poor survival. The NLR decreased after the introduction of TKIs and increased again when treatment failed. The response rate to TKI among the ATC patients were approximately 30% in practice. Although the duration of the response was short, several patients demonstrated long survival durations when TKI treatment was provided after successful multidisciplinary treatment to control local disease. Decreases in high NLR values during treatment may suggest the continued effect of TKIs.

Capsaicin induces mitochondrial dysfunction and apoptosis in anaplastic thyroid carcinoma cells via TRPV1-mediated mitochondrial calcium overload

Anaplastic thyroid cancer (ATC) is a rare malignancy and has a poor prognosis due to its aggressive behavior and resistance to treatments. Calcium (Ca2+) serves as a ubiquitous cellular second messenger and influences several tumor behaviors. Therefore, Ca2+ modulation is expected to be a novel therapeutic target in cancers. However, whether Ca2+ modulation is effective in ATC therapy remains unknown. In this study, we reported that capsaicin (CAP), a transient receptor potential vanilloid type1 (TRPV1) agonist, inhibited the viability of anaplastic thyroid cancer cells. Capsaicin treatment triggered Ca2+ influx by TRPV1 activation, resulting in disequilibrium of intracellular calcium homeostasis. The rapidly increased cytosolic Ca2+ concentration was mirrored in the mitochondria and caused a severe condition of mitochondrial calcium overload in ATC cells. In addition, the disruption of mitochondrial calcium homeostasis caused by capsaicin led to mitochondrial dysfunction in ATC cells, as evidenced by the production of mitochondrial reactive oxygen species (ROS), depolarization of mitochondrial membrane potential (ΔΨm), and opening of mitochondrial permeability transition pore (mPTP). Next, the resulting release of cyt c into the cytosol triggered apoptosome assembly and subsequent caspase activation and apoptosis. It was worth noting that both TRPV1 antagonist (capsazepine) and calcium chelator (BAPTA) could attenuate aberrant Ca2+ homeostasis, mitochondrial dysfunction and apoptosis induced by capsaicin treatment. Thus, our study demonstrated that capsaicin induced mitochondrial calcium overload and apoptosis in ATC cells through a TRPV1-mediated pathway. The better understanding of the anti-cancer mechanisms of calcium modulation provides a potential target for the ATC therapy.