RNA Profile of Cell Bodies and Exosomes Released by Tumorigenic and Non-Tumorigenic Thyroid Cells.

Tumor cells release exosomes, extracellular vesicle containing various bioactive molecules such as protein, DNA and RNA. The analysis of RNA molecules packaged in exosomes may provide new potential diagnostic or prognostic tumor biomarkers. The treatment of radioiodine-refractory aggressive thyroid cancer is still an unresolved clinical challenge, and the search for biomarkers that are detectable in early phase of the disease has become a fundamental goal for thyroid cancer research. By using transcriptome analysis, this study aimed to analyze the gene expression profiles of exosomes secreted by a non-tumorigenic thyroid cell line (Nthy-ori 3.1-exo) and a papillary thyroid cancer (TPC-1-exo) cell line, comparing them with those of cell bodies (Nthy-ori 3.1-cells and TPC-1-cells). A total of 9107 transcripts were identified as differentially expressed when comparing TPC-1-exo with TPC-1-cells and 5861 when comparing Nthy-ori 3.1-exo with Nthy-ori 3.1-cells. Among them, Sialic acid-binding immunoglobulin-like lectins 10 and 11 (SIGLEC10, SIGLEC11) and Keratin-associated protein 5 (KRTAP5-3) transcripts, genes known to be involved in cancer progression, turned out to be up-regulated only in TPC-1-exo. Gene ontology analysis revealed significantly enriched pathways, and only in TPC-1-exo were the differential expressed genes associated with an up-regulation in epigenetic processes. These findings provide a proof of concept that some mRNA species are specifically packaged in tumor-cell-derived exosomes and may constitute a starting point for the identification of new biomarkers for thyroid tumors.

A New Twist on a Classic: Enhancing Radioiodine Uptake in Advanced Thyroid Cancer.

Advanced differentiated thyroid cancer that is resistant to radioactive iodine therapy may become responsive with a unique treatment combination of chloroquine and vorinostat. This treatment was demonstrated in cellular and animal models of thyroid cancer to inhibit endocytosis of the plasma membrane-bound iodine transporter, NIS, and restore iodine uptake. See related article by Read et al., p. 1352.

Multilevel chitosan-gelatin particles loaded with P4HA1 siRNA suppress glioma development.

It has been reported that prolyl 4-hydroxylase subunit alpha 1 (P4HA1) promoted tumor growth and metastasis of glioma; thus, targeting P4HA1 may be a promising therapeutic strategy against glioma. In consideration of the instability of siRNA in vivo, the chitosan-gelatin microspheres loaded with P4HA1 siRNA (P4HA1 siRNA@CGM) were employed. Firstly, the gel electrophoresis and hemolytic test were performed to assess the stability and blood compatibility of P4HA1 siRNA@CGM. Then, methyl thiazolyl tetrazolium (MTT), cell colony formation, Transwell assay, wound healing assay, gliosphere formation, tube formation, and Western blot were performed to assess the effects of P4HA1 siRNA@CGM on the biological functions of glioma. Finally, 125I-labeled P4HA1 siRNA@CGM was injected into the xenograft mice, radionuclide imaging was recorded, Ki67 and terminal deoxynucleoitidyl transferase-mediated nick end labeling (TUNEL) staining was performed to assess the effects of P4HA1 siRNA@CGM on tumor growth and apoptosis of glioma in vivo. The results showed that P4HA1 siRNA and P4HA1 siRNA@CGM not only markedly inhibited the proliferation, metastasis, gliosphere formation, and the protein levels of interstitial markers (N-cadherin and vimentin) and the transcription factors of epithelial-mesenchymal transition (EMT) (Snail, Slug, and Twist1) in glioma cells, but also inhibited the tube formation in human brain microvascular endothelial cells (HBMECs), and P4HA1 siRNA@CGM exhibited the better inhibitory effects than P4HA1 siRNA. Above results suggested the feasibility of P4HA1 siRNA@CGM in the clinical treatment of glioma.

Long non-coding RNA EGOT is associated with 131iodine sensitivity and contributes to thyroid cancer progression by targeting miR-641/PTEN axis.

Thyroid cancer is a prevalent endocrine malignancy around the world. Radioactive 131iodine (131I) therapy is widely applied in TC patients, but the resistance affects its effectiveness in the clinics. Long non-coding RNA (lncRNA) EGOT has been reported to induce an inhibitory effect on cancer progression, but the specific function of EGOT in 131I resistance of TC cells remains unclear. Here, we successfully established 131I-resistant TC cells and evaluated the impact of EGOT on 131I resistance in the cells. Our data showed that EGOT and PTEN expression was reduced but the miR-641 expression was enhanced in 131I-resistant TC cells. EGOT inhibited viability, induced apoptosis and enhanced DNA damage in 131I-resistant TC cells. Mechanically, we identified that EGOT induced PTEN expression by targeting miR-641 in 131I-resistant TC cells. Moreover, the depletion of PTEN and miR-641 mimic reversed EGOT-relieved 131I resistance of TC cells in vitro. Thus, we conclude that lncRNA EGOT attenuated 131I resistance of TC cells by targeting miR-641/PTEN axis. The clinical functions of EGOT in TC therapy deserve to be validated in future exploration.

Visualizing mast cell migration to tumor sites using sodium iodide symporter of nuclear medicine reporter gene.

PURPOSE: Owing to the close relationship between mast cells and cancer progression, an imaging technique that can be applied in a clinical setting to explore the biological behavior of mast cells in the tumor microenvironment is needed. In this study, we visualized mast cell migration to lung tumor lesions in live mice using sodium iodide symporter (NIS) as a nuclear medicine reporter gene. EXPERIMENTAL DESIGN: The murine mast cell line MC-9 was infected with retrovirus including NIS, luciferase (as a surrogate marker for NIS), and Thy1.1 to generate MC-9/NFT cells. Radioiodine uptake was measured in MC-9/NFT cells, and an inhibition assay of radioiodine uptake using KCLO4 was also performed. Cell proliferation and FcεRI expression was examined in MC-9 and MC-9/NFT cells. The effect of mast cell-conditioned media (CM) on the proliferation of Lewis lung cancer (LLC) cells was examined. The migration level of MC-9/NFT cells was confirmed in the presence of serum-free media (SFM) and CM of cancer cells. After intravenous injection of MC-9/NFT cells into mice with an LLC tumor, I-124 PET/CT and biodistribution analysis was performed. RESULTS: MC-9/NFT cells exhibited higher radioiodine avidity compared to parental MC-9 cells; this increased radioiodine avidity in MC-9/NFT cells was reduced to basal level by KCLO4. Levels of FcεRI expression and cell proliferation were not different in parental MC-9 cell and MC-9/ NFT cells. The CM of MC-9/NFT cells increased cancer cell proliferation relative to that of the SFM. The migration level of MC-9/NFT cells was higher in the CM than the SFM of LLC cells. PET/CT imaging with I-124 clearly showed infiltration of reporter mast cells in lung tumor at 24 h after transfer, which was consistent with the findings of the biodistribution examination. CONCLUSION: These findings suggest that the sodium iodide symporter can serve as a reliable nuclear medicine reporter gene for non-invasively imaging the biological activity of mast cells in mice with lung tumors. Visualizing mast cells in the tumor microenvironment via a nuclear medicine reporter gene would provide valuable insights into their biological functions.

[Therapy concepts for thyroid carcinoma]. / Therapiekonzepte beim Schilddrüsenkarzinom.

Theranostics via the sodium iodide symporter (NIS) offer a unique option in differentiated thyroid carcinoma. The diagnostic and therapeutic nuclides have similar uptake and kinetics, making the NIS the most important theranostic target in this disease. Radioiodine refractory thyroid carcinomas (RRTC) are characterised by reduced/absent NIS expression, thus eliminating this structure as a theranostic target. Also due to limited therapeutic options, there are approaches to generate new theranostic targets in RRTC, via the expression of somatostatin receptors (SSTR) or the prostate-specific membrane antigen (PSMA), but the current evidence does not yet allow a final evaluation of the prospects of success.

LncRNA GLTC targets LDHA for succinylation and enzymatic activity to promote progression and radioiodine resistance in papillary thyroid cancer.

Dysregulation of long noncoding RNAs (lncRNAs) has been associated with the development and progression of many human cancers. Lactate dehydrogenase A (LDHA) enzymatic activity is also crucial for cancer development, including the development of papillary thyroid cancer (PTC). However, whether specific lncRNAs can regulate LDHA activity during cancer progression remains unclear. Through screening, we identified an LDHA-interacting lncRNA, GLTC, which is required for the increased aerobic glycolysis and cell viability in PTC. GLTC was significantly upregulated in PTC tissues compared with nontumour thyroid tissues. High expression of GLTC was correlated with more extensive distant metastasis, a larger tumour size, and poorer prognosis. Mass spectrometry revealed that GLTC, as a binding partner of LDHA, promotes the succinylation of LDHA at lysine 155 (K155) via competitive inhibition of the interaction between SIRT5 and LDHA, thereby promoting LDHA enzymatic activity. Overexpression of the succinylation mimetic LDHAK155E mutant restored glycolytic metabolism and cell viability in cells in which metabolic reprogramming and cell viability were ceased due to GLTC depletion. Interestingly, GLTC inhibition abrogated the effects of K155-succinylated LDHA on radioiodine (RAI) resistance in vitro and in vivo. Taken together, our results indicate that GLTC plays an oncogenic role and is an attractive target for RAI sensitisation in PTC treatment.

Overexpression of Both Human Sodium Iodide Symporter (NIS) and BRG1-Bromodomain Synergistically Enhances Radioiodine Sensitivity by Stabilizing p53 through NPM1 Expression.

Improved therapeutic strategies are required to minimize side effects associated with radioiodine gene therapy to avoid unnecessary damage to normal cells and radiation-induced secondary malignancies. We previously reported that codon-optimized sodium iodide symporter (oNIS) enhances absorption of I-131 and that the brahma-associated gene 1 bromodomain (BRG1-BRD) causes inefficient DNA damage repair after high-energy X-ray therapy. To increase the therapeutic effect without applying excessive radiation, we considered the combination of oNIS and BRG1-BRD as gene therapy for the most effective radioiodine treatment. The antitumor effect of I-131 with oNIS or oNIS+BRD expression was examined by tumor xenograft models along with functional assays at the cellular level. The synergistic effect of both BRG1-BRD and oNIS gene overexpression resulted in more DNA double-strand breaks and led to reduced cell proliferation/survival rates after I-131 treatment, which was mediated by the p53/p21 pathway. We found increased p53, p21, and nucleophosmin 1 (NPM1) in oNIS- and BRD-expressing cells following I-131 treatment, even though the remaining levels of citrulline and protein arginine deiminase 4 (PAD4) were unchanged at the protein level.

HIF-1α/YAP Signaling Rewrites Glucose/Iodine Metabolism Program to Promote Papillary Thyroid Cancer Progression.

Background: The management of aggressive and progressive metastatic papillary thyroid cancer (PTC) is very difficult. An inverse relationship between radioiodine and F-18 fluorodeoxyglucose (FDG) uptake (''flip-flop'' phenomenon) is described for invasive PTC during dedifferentiation. However, no satisfactory biologic explanation for this phenomenon. Hypoxia is an important microenvironmental factor that promotes cancer progression and glycolysis. The Hippo-YAP is a highly conserved tumor suppressor pathway and contributes to cancer metabolic reprogramming. Thus, we investigated the underlying molecular mechanisms of glucose/iodine metabolic reprogramming in PTC, focusing on the tumor hypoxia microenvironment and Hippo-YAP signaling. Methods: Immunohistochemistry staining was conducted to evaluate the expressions of hypoxia-inducible factor 1α (HIF-1α), yes-associated protein (YAP), glucose transporters 1 (GLUT1) and sodium iodine symporter (NIS) in matched PTC and the adjacent noncancerous tissues. PTC cell lines were cultured under normoxic (20% O2) and hypoxic (1% O2) conditions and the glycolysis level and NIS expression were measured. Further, we characterized the molecular mechanism of glucose/iodine metabolic reprogramming in PTC cell. Finally, we validated the results in vivo by establishing subcutaneous xenografts in nude mice. Results: The expression levels of HIF1-α, YAP and GLUT1 were upregulated in PTC tissues and YAP expression was positively associated with HIF-1α, GLUT1 and TNM stages. Meanwhile, the expression of NIS was negatively correlated with YAP. Further, in vitro studies indicated that hypoxia-induced YAP activation was critical for accelerating glycolysis and reducing NIS expression in PTC cells. Inhibition of YAP had the opposite effects in vitro and tumorigenicity in vivo. Hypoxia inhibited the Hippo signaling pathway resulting in the inactivation of YAP phosphorylation, further promoting the nuclear localization of YAP in PTC cells. The mechanism is that hypoxic stress promoted YAP binding to HIF-1α in the nucleus and maintained HIF-1α protein stability. The YAP/HIF-1α complex bound and directly activated the GLUT1 transcription to accelerate glycolysis. Meanwhile, HIF-1α/YAP signaling might indirectly reduce the expression of NIS by promoting the output of MAPK signaling. In vivo studies confirmed the YAP-mediated reprogramming of glucose/iodine metabolism promoted PTC progression. Conclusions: Collectively, our data revealed a novel regulatory mechanism of the glucose/iodine metabolic program rewritten by HIF-1α/YAP signaling in PTC. Inhibition of HIF-1α/YAP signaling alone or in combination with other potential markers may effectively combat aggressive PTC.

Inhibition of ALK-Signaling Overcomes STRN-ALK-Induced Downregulation of the Sodium Iodine Symporter and Restores Radioiodine Uptake in Thyroid Cells.

Background: Radioiodine (RAI) is commonly used for thyroid cancer treatment, although its therapeutic benefits are restricted to iodine-avid tumors. The RAI-refractory disease develops with tumor dedifferentiation involving loss of sodium-iodine symporter (NIS). Thyroid cancers driven by ALK fusions are prone to dedifferentiation, and whether targeted ALK inhibition may enhance RAI uptake in these tumors remains unknown. The aim of this study was to determine the levels of NIS expression during the progression of ALK fusion-driven thyroid cancer, assess the effects of ALK activation on NIS-mediated RAI uptake, and test pharmacological options for its modulation. Methods: The expression of NIS at different stages of ALK-driven carcinogenesis was analyzed using a mouse model of STRN-ALK-driven thyroid cancer. For in vitro experiments, a system of doxycycline-inducible expression of STRN-ALK was generated using PCCL3 normal thyroid cells. The STRN-ALK-induced effects were evaluated with quantitative reverse transcription polymerase chain reaction, Western blot, immunofluorescence, RNA sequencing, and gene sets pathways analyses. RAI uptake was measured using 131I. Treatment experiments were done with FDA-approved ALK inhibitors (crizotinib and ceritinib), MEK inhibitor selumetinib, and JAK1/2 inhibitor ruxolitinib. Results: We found that Nis downregulation occurred early in ALK-driven thyroid carcinogenesis, even at the stage of well-differentiated cancer, with a complete loss in poorly differentiated thyroid carcinomas. Acute STRN-ALK expression in thyroid cells resulted in increased MAPK, JAK/STAT3, and PI3K/AKT/mTOR signaling outputs associated with significant ALK-dependent downregulation of the majority of thyroid differentiation and iodine metabolism/transport genes, including Slc5a5 (Nis), Foxe1, Dio1, Duox1/2, Duoxa2, Glis3, Slc5a8, and Tg. Moreover, STRN-ALK expression in thyroid cells induced a significant loss of membranous NIS and a fourfold decrease of the NIS-mediated RAI uptake, which were reversed by ALK inhibitors crizotinib and ceritinib. In addition, a strong dose-dependent restoration of NIS with its membranous redistribution in STRN-ALK-expressing thyroid cells was observed after inhibition of MAPK signaling with selumetinib, which exhibited a cumulative effect with JAK1/2 inhibitor ruxolitinib. Conclusions: The findings of this preclinical study showed that ALK fusion-induced downregulation of NIS, the prerequisite of RAI refractoriness, could be reversed in thyroid cells by either direct inhibition of ALK or its downstream signaling pathways.

The effect of sodium iodide symporter protein on ablation success in patients with differentiated thyroid cancer.

OBJECTIVE: This study aimed to investigate immunohistochemical staining of sodium iodide symporter (NIS) and its effect on response to I-131 therapy in differentiated thyroid carcinoma patients. METHODS: We evaluated NIS expression, the intracellular distribution of NIS, iodine-131 uptake in residual tissues on post-ablation I-131 whole body scan, and the ablation status after 100 mCi I-131 therapy. We also investigated NIS expression and localization in tumoral paraffin-embedded tissues. RESULTS: In this retrospective study, 35 patients (mean age 44.17 ± 12.9 years, 27 female, 8 male) were studied. Twenty-one of these patients responded to radioiodine therapy, and 14 did not. NIS expression and iodine-131 uptake in residual tissues post-ablation I-131 whole body scan were not statistically significant. When we compared the patients who responded to radioiodine therapy and the poor responder group, NIS expression and iodine-131 uptake in residual tissues did not demonstrate statistically significant difference [(p = 0.308) (p = 0.985) respectively]. 47.6% of the patients in the successful ablation group and 85.7% in the unsuccessful ablation group had intracellular NIS immunostaining. The difference was not statistically significant (p = 0.139). 52.4% of the patients in the successful ablation group and 7% in the unsuccessful ablation group had NIS immunostaining at the basolateral membrane. The difference was statistically significant (p < 0.05). CONCLUSIONS: In conclusion, we did not find any significant difference between successful and unsuccessful ablation groups in terms of NIS expression; however, we concluded that the intracellular (cytoplasmic) localization of NIS is one of the leading causes of ablation failure regardless of NIS expression in DTC patients.

Efficacy of Combination Therapy with Lenvatinib and Radioactive Iodine in Thyroid Cancer Preclinical Model.

Patients with differentiated thyroid cancer (DTC) usually have good prognosis, while those with advanced disease have poor clinical outcomes. This study aimed to investigate the antitumor effects of combination therapy with lenvatinib and 131I (CTLI) using three different types of DTC cell lines with different profiling of sodium iodide symporter (NIS) status. The radioiodine accumulation study revealed a significantly increased radioiodine uptake in K1-NIS cells after lenvatinib treatment, while there was almost no uptake in K1 and FTC-133 cells. However, lenvatinib administration before radioiodine treatment decreased radioiodine uptake of K1-NIS xenograft tumor in the in vivo imaging study. CTLI synergistically inhibited colony formation and DTC cell migration, especially in K1-NIS cells. Finally, 131I treatment followed by lenvatinib administration significantly inhibited tumor growth of the NIS-expressing thyroid cancer xenograft model. These results provide important clinical implications for the combined therapy that lenvatinib should be administered after 131I treatment to maximize the treatment efficacy. Our synergistic treatment effects by CTLI suggested its effectiveness for RAI-avid thyroid cancer, which retains NIS function. This potential combination therapy suggests a powerful and tolerable new therapeutic strategy for advanced thyroid cancer.

Sinomenine Hydrochloride Promotes TSHR-Dependent Redifferentiation in Papillary Thyroid Cancer.

Radioactive iodine (RAI) plays an important role in the diagnosis and treatment of papillary thyroid cancer (PTC). The curative effects of RAI therapy are not only related to radiosensitivity but also closely related to the accumulation of radionuclides in the lesion in PTC. Sinomenine hydrochloride (SH) can suppress tumor growth and increase radiosensitivity in several tumor cells, including PTC. The aim of this research was to investigate the therapeutic potential of SH on PTC cell redifferentiation. In this study, we treated BCPAP and TPC-1 cells with SH and tested the expression of thyroid differentiation-related genes. RAI uptake caused by SH-pretreatment was also evaluated. The results indicate that 4 mM SH significantly inhibited proliferation and increased the expression of the thyroid iodine-handling gene compared with the control group (p < 0.005), including the sodium/iodide symporter (NIS). Furthermore, SH also upregulated the membrane localization of NIS and RAI uptake. We further verified that upregulation of NIS was associated with the activation of the thyroid-stimulating hormone receptor (TSHR)/cyclic adenosine monophosphate (cAMP) signaling pathway. In conclusion, SH can inhibit proliferation, induce apoptosis, promote redifferentiation, and then increase the efficacy of RAI therapy in PTC cells. Thus, our results suggest that SH could be useful as an adjuvant therapy in combination with RAI therapy in PTC.

Adagrasib, a KRAS G12C inhibitor, reverses the multidrug resistance mediated by ABCB1 in vitro and in vivo.

BACKGROUND: Multidrug resistance (MDR) is a complex phenomenon that frequently leads to chemotherapy failure during cancer treatment. The overexpression of ATP-binding cassette (ABC) transporters represents the major mechanism contributing to MDR. To date, no effective MDR modulator has been applied in clinic. Adagrasib (MRTX849), a specific inhibitor targeting KRAS G12C mutant, is currently under investigation in clinical trials for the treatment of non-small cell lung cancer (NSCLC). This study focused on investigating the circumvention of MDR by MRTX849. METHODS: The cytotoxicity and MDR reversal effect of MRTX849 were assessed by MTT assay. Drug accumulation and drug efflux were evaluated by flow cytometry. The MDR reversal by MRTX849 in vivo was investigated in two ABCB1-overexpressing tumor xenograft models in nude mice. The interaction between MRTX849 and ABCB1 substrate binding sites was studied by the [125I]-IAAP-photoaffinity labeling assay. The vanadate-sensitive ATPase assay was performed to identify whether MRTX849 would change ABCB1 ATPase activity. The effect of MRTX849 on expression of ABCB1 and PI3K/AKT signaling molecules was examined by flow cytometry, Western blot and Quantitative Real-time PCR analyses. RESULTS: MRTX849 was shown to enhance the anticancer efficacy of ABCB1 substrate drugs in the transporter-overexpressing cells both in vitro and in vivo. The MDR reversal effect was specific against ABCB1 because no similar effect was observed in the parental sensitive cells or in ABCG2-mediated MDR cells. Mechanistically, MRTX849 increased the cellular accumulation of ABCB1 substrates including doxorubicin (Dox) and rhodamine 123 (Rho123) in ABCB1-overexpressing MDR cells by suppressing ABCB1 efflux activity. Additionally, MRTX849 stimulated ABCB1 ATPase activity and competed with [125I]-IAAP for photolabeling of ABCB1 in a concentration-dependent manner. However, MRTX849 did not alter ABCB1 expression or phosphorylation of AKT/ERK at the effective MDR reversal drug concentrations. CONCLUSIONS: In summary, MRTX849 was found to overcome ABCB1-mediated MDR both in vitro and in vivo by specifically attenuating ABCB1 efflux activity in drug-resistant cancer cells. Further studies are warranted to translate the combination of MRTX849 and conventional chemotherapy to clinical application for circumvention of MDR. Video Abstract.

I-131 false-positive uptake in a thymic cyst with expression of the sodium-iodide symporter: A case report.

RATIONALE: I-131 radioiodine false-positive findings in postoperative patients with differentiated thyroid cancer (DTC) should be recognized to avoid unnecessary therapies. PATIENT CONCERNS AND DIAGNOSES: A 50-year-old man underwent I-131 therapy 3 times, including the initial ablative therapy after total thyroidectomy for papillary thyroid cancer. The initial I-131 posttherapeutic whole-body scintigraphy showed 2 cervical and one superior mediastinal focal I-131 positive uptake lesions. The serum thyroglobulin level was negative every time when the radioiodine therapy was performed. Although the 2 cervical positive uptake lesions disappeared after the second therapy, the superior mediastinal I-131 positive uptake persisted even after the third therapy, and this lesion was suspicion of I-131 therapy-resistant node metastasis. INTERVENTIONS AND OUTCOMES: The lesion was resected, and the pathological diagnosis with immune-histochemical analysis was a thymic cyst with thymic epithelial cells having a weak expression of the sodium-iodide symporter (NIS). LESSONS: The false-positive result may be attributed to the NIS expression in the thymic cyst epithelial cells. It is necessary to include a thymic cyst in the differential diagnosis, when I-131 uptake is noted in the superior mediastinal region on I-131 posttherapeutic scans of patients with postoperative DTC. Although the I-131 positive uptake in a thymic cyst may be influenced by the I-131 administered dose and scan timing after I-131 administration, the NIS expression may be essential to the false-positive uptake in a thymic cyst.

Engineering a HEK-293T exosome-based delivery platform for efficient tumor-targeting chemotherapy/internal irradiation combination therapy.

Exosomes are nanoscale monolayer membrane vesicles that are actively endogenously secreted by mammalian cells. Currently, multifunctional exosomes with tumor-targeted imaging and therapeutic potential have aroused widespread interest in cancer research. Herein, we developed a multifunctional HEK-293T exosome-based targeted delivery platform by engineering HEK-293T cells to express a well-characterized exosomal membrane protein (Lamp2b) fused to the αv integrin-specific iRGD peptide and tyrosine fragments. This platform was loaded with doxorubicin (Dox) and labeled with radioiodine-131 (131I) using the chloramine-T method. iRGD exosomes showed highly efficient targeting and Dox delivery to integrin αvß3-positive anaplastic thyroid carcinoma (ATC) cells as demonstrated by confocal imaging and flow cytometry in vitro and an excellent tumor-targeting capacity confirmed by single-photon emission computed tomography-computed tomography after labeling with 131I in vivo. In addition, intravenous injection of this vehicle delivered Dox and 131I specifically to tumor tissues, leading to significant tumor growth inhibition in an 8505C xenograft mouse model, while showing biosafety and no side effects. These as-developed multifunctional exosomes (denoted as Dox@iRGD-Exos-131I) provide novel insight into the current treatment of ATC and hold great potential for improving therapeutic efficacy against a wide range of integrin αvß3-overexpressing tumors.

Capsaicin restores sodium iodine symporter-mediated radioiodine uptake through bypassing canonical TSH‒TSHR pathway in anaplastic thyroid carcinoma cells.

Anaplastic thyroid cancer (ATC) is a rare but highly lethal disease. ATCs are resistant to standard therapies and are extremely difficult to manage. The stepwise cell dedifferentiation results in the impairment of the iodine-metabolizing machinery and the infeasibility of radioiodine treatment in ATC. Hence, reinducing iodine-metabolizing gene expression to restore radioiodine avidity is considered as a promising strategy to fight against ATC. In the present study, capsaicin (CAP), a natural potent transient receptor potential vanilloid type 1 (TRPV1) agonist, was discovered to reinduce ATC cell differentiation and to increase the expression of thyroid transcription factors (TTFs including TTF-1, TTF-2, and PAX8) and iodine-metabolizing proteins, including thyroid-stimulating hormone receptor (TSHR), thyroid peroxidase, and sodium iodine symporter (NIS), in two ATC cell lines, 8505C and FRO. Strikingly, CAP treatment promoted NIS glycosylation and its membrane trafficking, resulting in a significant enhancement of radioiodine uptake of ATC cells in vitro. Mechanistically, CAP-activated TRPV1 channel and subsequently triggered Ca2+ influx, cyclic adenosine monophosphate (cAMP) generation, and cAMP-responsive element-binding protein (CREB) signal activation. Next, CREB recognized and bound to the promoter of SLC5A5 to facilitate its transcription. Moreover, the TRPV1 antagonist CPZ, the calcium chelator BAPTA, and the PKA inhibitor H-89 effectively alleviated the redifferentiation exerted by CAP, demonstrating that CAP might improve radioiodine avidity through the activation of the TRPV1‒Ca2+/cAMP/PKA/CREB signaling pathway. In addition, our study indicated that CAP might trigger a novel cascade to redifferentiate ATC cells and provide unprecedented opportunities for radioiodine therapy in ATC, bypassing canonical TSH‒TSHR pathway.

KMT2B promotes SHPRH expression to regulate 131I sensitivity in thyroid carcinoma cells by affecting FYN protein stability.

Radioiodine (131I) is one of the most well-known and widely used targeted therapies. In thyroid carcinoma (THCA), it has been applied for more than eight decades and is still being utilized to eliminate remnants after resection and to reduce tumor metastases. Here, we aimed to investigate if lysine methyltransferase 2B (KMT2B) silencing could confer 131I resistance to THCA cells and the epigenetic mechanism behind. RT-qPCR, immunohistochemistry and western blot revealed that KMT2B was poorly expressed in THCA cells, and 131I resistance of cells led to a further decrease in KMT2B expression. EdU, colony formation, TUNEL, and tumor growth and metastasis assays showed that overexpression of KMT2B sensitized THCA cell to 131I and inhibited cell growth and metastasis. Further bioinformatics prediction and functional assay validation revealed that KMT2B elevated SHPRH expression via H3K4me3 modification in the SHPRH promoter, and that SHPRH modulated FYN ubiquitination, thereby promoting its protein degradation. We finally proved that the 131I-resistant cells regained resistance to 131I by FYN overexpression in the presence of KMT2B overexpression in vitro and in vivo. Therefore, we conclude that the overexpression of KMT2B represents a potential target for THCA therapy.

Curcumin enhances the membrane trafficking of the sodium iodide symporter and augments radioiodine uptake in dedifferentiated thyroid cancer cells via suppression of the PI3K-AKT signaling pathway.

Radioactive iodine (RAI) is commonly used to treat differentiated thyroid cancer (DTC). A major challenge is the dedifferentiation of DTC with the loss of radioiodine uptake. Patients with distant metastases have persistent or recurrent disease and develop resistance to RAI therapy due to tumor dedifferentiation. Hence, tumor redifferentiation to restore sensitivity to RAI therapy is considered a promising strategy to overcome RAI resistance. In the present study, curcumin, a natural polyphenolic compound, was found to re-induce cell differentiation and increase the expression of thyroid-specific transcription factors, TTF-1, TTF-2 and transcriptional factor paired box 8 (PAX8), and iodide-metabolizing proteins, including thyroid stimulating hormone receptor (TSHR), thyroid peroxidase (TPO) and sodium iodide symporter (NIS) in dedifferentiated thyroid cancer cell lines, BCPAP and KTC-1. Importantly, curcumin enhanced NIS glycosylation and its membrane trafficking, resulting in a significant improvement of radioiodine uptake in vitro. Additionally, AKT knockdown phenocopied the restoration of thyroid-specific gene expression; however, ectopic expressed AKT inhibited curcumin-induced up-regulation of NIS protein, demonstrating that curcumin might improve radioiodine sensitivity via the inhibition of the PI3K-AKT-mTOR signaling pathway. Our study demonstrates that curcumin could represent a promising adjunctive therapy for restoring iodide avidity and improve radioiodine therapeutic efficacy in patients with RAI-refractory thyroid carcinoma.