Anaplastic thyroid cancer: a comprehensive review of novel therapy

Evaluating the effectiveness of targeted therapies for thyroid carcinoma: an updated meta-analysis

Background

At present, most of the targeted therapies for thyroid carcinoma are in the clinical trial stage, and there is still no strong evidence to confirm their clinical effect. The aim of this meta-analysis was to evaluate the outcome of targeted therapies and provide quantitative evidence.

Method

Ovid, PubMed, EMBAS, ClinicalTrails.gov, and Cochrane Library electronic databases were searched until September 1, 2019. Randomized controlled studies (RCTs) studies that compared the treatment of thyroid carcinoma with the targeted therapies of utility and complications were analyzed.

Results

The study included 5 studies with a total of 1,615 patients, with 991 cases in the drug group and 624 cases in the placebo group. The meta-analysis indicated that compared with the placebo group, the progression-free survival (PFS) rate of the drug group was significantly improved. The PFS of the drug group was 10.8 to 30.5 months, compared with 4 to 19.3 months for the placebo group (6 months PFS: OR =3.23, 95% CI: 2.57 to 4.05, P<0.00001, 12 months PFS: OR =3.38, 95% CI: 2.58 to 4.42, P<0.00001, 18 months PFS: OR =2.48, 95% CI: 1.74 to 3.54, P<0.00001). Overall survival (OS) did not differ significantly in the study (6 months: OR =1.53, 95% CI: 1.00 to 2.35, P=0.05, 12 months: OR =1.26, 95% CI: 0.94 to 1.69, P=0.12, 18 months: OR =1.11, 95% CI: 0.87 to 1.42, P=0.39). The incidence of adverse reactions in the drug group was significantly higher than that in the placebo group (OR =4.76, 95% CI: 3.45 to 6.57, P<0.00001), and the subgroup of adverse reactions was still significantly higher than that in the placebo group.

Conclusions

This meta-analysis revealed that the targeted drugs can significantly prolong PFS in patients with thyroid carcinoma, but the targeted drugs did not prolong the OS. Although the incidence of adverse reactions was significantly higher than that of the placebo group, the patients were still tolerable in drug group.

Meta-analysis of microarray datasets identify several chromosome segregation-related cancer/testis genes potentially contributing to anaplastic thyroid carcinoma

AIM

Anaplastic thyroid carcinoma (ATC) is the most lethal thyroid malignancy. Identification of novel drug targets is urgently needed.

MATERIALS & METHODS

We re-analyzed several GEO datasets by systematic retrieval and data merging. Differentially expressed genes (DEGs) were filtered out. We also performed pathway enrichment analysis to interpret the data. We predicted key genes based on protein-protein interaction networks, weighted gene co-expression network analysis and genes' cancer/testis expression pattern. We also further characterized these genes using data from the Cancer Genome Atlas (TCGA) project and gene ontology annotation.

RESULTS

Cell cycle-related pathways were significantly enriched in upregulated genes in ATC. We identified TRIP13, DLGAP5, HJURP, CDKN3, NEK2, KIF15, TTK, KIF2C, AURKA and TPX2 as cell cycle-related key genes with cancer/testis expression pattern. We further uncovered that most of these putative key genes were critical components during chromosome segregation.

CONCLUSION

We predicted several key genes harboring potential therapeutic value in ATC. Cell cycle-related processes, especially chromosome segregation, may be the key to tumorigenesis and treatment of ATC.

Lenvatinib for Anaplastic Thyroid Cancer and Lenvatinib-Induced Thyroid Dysfunction

BACKGROUND

Lenvatinib is an oral multitargeted tyrosine kinase inhibitor that has an anticancer action in patients with differentiated thyroid cancer that is refractory to radioiodine. Knowledge of the efficacy and safety of lenvatinib in patients with anaplastic thyroid cancer (ATC) is limited. Tyrosine kinase inhibitors frequently cause hypothyroidism, but the incidence of hypothyroidism with lenvatinib is unclear.

OBJECTIVES

We conducted a retrospective study to investigate the efficacy and safety of lenvatinib in ATC.

METHODS

Five patients with unresectable ATC were enrolled. Lenvatinib 24 mg once daily was administered until disease progression, unmanageable toxicity, withdrawal, or death occurred. We retrospectively analyzed the objective response rate (ORR), time to progression (TTP), overall survival, and safety.

RESULTS

Three of the 5 patients (60%) had a partial response, and 5 (40%) had stable disease. The ORR was 60%. Median TTP was 88 days, and overall survival was 165 days. Hypothyroidism was a common treatment-related adverse effect; 4 patients (80%) had hypothyroidism of any grade. These 4 patients had not undergone total thyroidectomy prior to lenvatinib administration, and the other patient had undergone total thyroidectomy. Treatment-related adverse effects of any grade were hypertension in 80% of patients, diarrhea in 40%, fatigue in 80%, and decreased appetite in 80%.

CONCLUSIONS

Lenvatinib is an effective treatment and may improve the prognosis of unresectable ATC. Four of the 5 patients had hypothyroidism, which may have been associated with treatment-induced injury of the thyroid gland. There were many treatment-related adverse effects, most of which were manageable by dose modification and medical therapy.

Silencing of hTERT blocks growth and migration of anaplastic thyroid cancer cells

Mutations in the hTERT promoter responsible for constitutive telomerase activity are the most frequent genetic alteration detected in anaplastic thyroid cancer (ATC), and proposed as diagnostic and prognostic biomarker in these tumours. In this study we analyzed hTERT expression in a series of human ATCs and investigated the effects of small-interfering RNA-mediated silencing of hTERT on viability and migration and invasive properties of three human ATC cell lines. Expression of hTERT mRNA resulted increased in 8/10 ATCs compared to normal thyroid tissues. Silencing of hTERT in CAL-62, 8505C and SW1736 cells did not modify telomere length but determined a significant decrease (about 50%) of cell proliferation in all cell lines and a great reduction (about 50%) of migration and invasion capacity. These finding demonstrate that hTERT may be considered as a molecular target for ATC treatment.

Clinical presentation, treatment and outcome of anaplastic thyroid carcinoma: results of a multicenter study in Germany

CONTEXT

Anaplastic thyroid carcinoma (ATC) is an orphan disease and confers a dismal prognosis. Standard treatment is not established.

OBJECTIVE

The aim of this study is to describe clinical characteristics, current treatment regimens and outcome of ATC and to identify clinical prognostic markers and treatment factors associated with improved prognosis.

DESIGN

Retrospective cohort study at five German tertiary care centers.

PATIENTS AND METHODS

Totally 100 ATC patients diagnosed between 2000 and 2015 were included in the analysis. Disease-specific overall survival (OS) was compared with the Kaplan-Meier method and log-rank test; Cox proportional hazard model was used to identify risk factors.

RESULTS

The 6-month, 1-year and 5-year disease-specific OS rates were 37, 28 and 5%, respectively. Stage-dependent OS at 6 months was 78, 54 and 18% for stage IVA, B and C, respectively. 29% patients survived >1 year. Multivariate analysis of OS identified age ≥70 years, incomplete local resection status and the presence of distant metastasis as significant risk factors associated with shorter survival. Radical surgery (hazard ratio [HR] 2.20, 95% confidence interval (CI) 1.19-4.09, P = 0.012), external beam radiation therapy (EBRT) ≥40 Gy (HR = 0.34, 0.15-0.76, P = 0.008) and any kind of chemotherapy (CTX) (HR = 11.64, 2.42-60.39, P = 0.003) were associated with longer survival in multivariate analyses adjusted for age and tumor stage. A multimodal treatment regimen was significantly associated with a survival benefit (HR = 1.04, 1.01-1.08, P < 0.0001) only in IVC patients.

CONCLUSION

Disease-specific OS is still poor in ATC. Treatment factors associated with improved OS provide a rationale to devise treatment pathways for routine care. Collaborative research structures should be aimed to advance treatment of ATC.

Genomic and transcriptomic hallmarks of poorly differentiated and anaplastic thyroid cancers

BACKGROUND

Poorly differentiated thyroid cancer (PDTC) and anaplastic thyroid cancer (ATC) are rare and frequently lethal tumors that so far have not been subjected to comprehensive genetic characterization.

METHODS

We performed next-generation sequencing of 341 cancer genes from 117 patient-derived PDTCs and ATCs and analyzed the transcriptome of a representative subset of 37 tumors. Results were analyzed in the context of The Cancer Genome Atlas study (TCGA study) of papillary thyroid cancers (PTC).

RESULTS

Compared to PDTCs, ATCs had a greater mutation burden, including a higher frequency of mutations in TP53, TERT promoter, PI3K/AKT/mTOR pathway effectors, SWI/SNF subunits, and histone methyltransferases. BRAF and RAS were the predominant drivers and dictated distinct tropism for nodal versus distant metastases in PDTC. RAS and BRAF sharply distinguished between PDTCs defined by the Turin (PDTC-Turin) versus MSKCC (PDTC-MSK) criteria, respectively. Mutations of EIF1AX, a component of the translational preinitiation complex, were markedly enriched in PDTCs and ATCs and had a striking pattern of co-occurrence with RAS mutations. While TERT promoter mutations were rare and subclonal in PTCs, they were clonal and highly prevalent in advanced cancers. Application of the TCGA-derived BRAF-RAS score (a measure of MAPK transcriptional output) revealed a preserved relationship with BRAF/RAS mutation in PDTCs, whereas ATCs were BRAF-like irrespective of driver mutation.

CONCLUSIONS

These data support a model of tumorigenesis whereby PDTCs and ATCs arise from well-differentiated tumors through the accumulation of key additional genetic abnormalities, many of which have prognostic and possible therapeutic relevance. The widespread genomic disruptions in ATC compared with PDTC underscore their greater virulence and higher mortality.

FUNDING

This work was supported in part by NIH grants CA50706, CA72597, P50-CA72012, P30-CA008748, and 5T32-CA160001; the Lefkovsky Family Foundation; the Society of Memorial Sloan Kettering; the Byrne fund; and Cycle for Survival.

Effects of BP-14, a novel cyclin-dependent kinase inhibitor, on anaplastic thyroid cancer cells

Anaplastic thyroid carcinoma (ATC) is an extremely aggressive human malignancy characterized by a marked degree of invasiveness, absense of features of thyroid differentiation and resistance to current medical treatment. It is well known that ATCs are characterized by deregulation of genes related to cell cycle regulation, i.e., cyclin-dependent kinases (CDKs) and endogenous cyclin-dependent kinase inhibitors (CDKIs). Therefore, in the present study, the effect of a novel exogenous cyclin-dependent kinase inhibitor, BP-14, was investigated in three human ATC cell lines. The ATC-derived cell lines FRO, SW1736 and 8505C were treated with BP-14 alone or in combination with the mTOR inhibitor everolimus. In all ATC cell lines, treatment with BP-14 decreased cell viability and, in two of them, BP-14 modified expression of genes involved in epithelial-mesenchymal transition. Thus, our data indicate that BP-14 is a potential new compound effective against ATC. Combined treatment with BP-14 and the mTOR inhibitor everolimus had a strong synergistic effect on cell viability in all three cell lines, suggesting that the combined used of CDK and mTOR inhibitors may be a useful strategy for ATC treatment.

4-IPP, a selective MIF inhibitor, causes mitotic catastrophe in thyroid carcinomas

Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine that is over-expressed in several human neoplastic cells. When MIF binds its receptor (CD74) and co-receptor (CD44), it initiates signaling cascades that orchestrate cell proliferation and survival, and it can directly modulate the activity of AMPK. These activities indicate that MIF potentially regulates cell survival and metabolism. We found that MIF was primarily co-expressed with CD74 in 16 out of 23 papillary thyroid carcinoma (PTC) and in all the 27 available anaplastic thyroid carcinoma (ATC) biopsy samples. MIF and CD74 were co-expressed in TPC-1 and HTC-C3 cell lines. The selective MIF inhibitor, 4-iodo-6-phenylpyrimidine (4-IPP), blocked MIF/CD74 internalization, activated JNK, and dose-dependently inhibited proliferation inducing apoptosis and mitotic cell death. In two CD74-negative cell lines, NIM-1 and K1, 4-IPP treatment partially reduced proliferation. Coordinated MIF and CD74 expression appeared to confer in tumor cells the plasticity necessary to escape cell cycle regulation, metabolic changes, and stress conditions. MIF/CD74 signaling removal made cells susceptible to apoptosis and mitotic cell death. This finding suggests a possible avenue for targeting DNA endoreduplication, thus preventing the proliferation of therapy-resistant cell subpopulations. This study highlights MIF/CD74 axis as an important player in the biology of aggressive thyroid neoplasms.

MicroRNA-126 suppresses proliferation of undifferentiated (BRAF(V600E) and BRAF(WT)) thyroid carcinoma through targeting PIK3R2 gene and repressing PI3K-AKT proliferation-survival signalling pathway

BACKGROUND

The objectives of this study are to investigate the expression of miR-126 and evaluate its effect on proliferation in undifferentiated thyroid carcinoma.

METHODS

miR-126 expression of undifferentiated thyroid carcinoma cell lines 8505C (BRAF(V600E/V600E)), BHT-101 (BRAF(V600E/WT)) and MB-1 (BRAF(WT/WT)) were quantified with q-PCR. These cell lines were transiently transfected with exogenous miR-126 (mimic). Following transfection, proliferation effects were observed through MTS proliferation assay and colony formation abilities. Immunofluorescence imaging and Western blot assay were also done to check target proteins expression.

RESULTS

Under-expression (p<0.05) of miR-126 was noted in BRAF(V600E) mutated undifferentiated thyroid carcinoma cells (8505C and BHT-101), but no change in expression was noted in non BRAF(V600E) mutated undifferentiated thyroid carcinoma cells (MB-1). In addition, a 30-50% drop in proliferation ability and a 35-45% reduction in colony formation capability were noticed in miR-126 mimic transfected group when compared to control group. Furthermore, immunofluorescence images showed reduced expression of p85β and p-AKT protein in miR-126 mimic transfected cells when compared to un-transfected cells. Also, Western blot analysis revealed a 34-40% suppression of p85β protein and a 21-53% drop in active AKT kinase (p-AKT) protein in miR-126 mimic transfected group when compared to control group.

CONCLUSIONS

Expression of miR-126 was down-regulated in BRAF(V600E) mutated undifferentiated thyroid carcinoma. In addition, miR-126 was found to act as proliferation suppressor targeting PIK3R2 gene and reducing p85β (a regulatory subunit of PI3K kinase) protein translation and lower AKT kinase activity. Therefore, miR-126 could be a potential therapeutic tool in the treatment of undifferentiated thyroid carcinoma.

Synergy between HDAC and PARP Inhibitors on Proliferation of a Human Anaplastic Thyroid Cancer-Derived Cell Line

Anaplastic thyroid carcinoma (ATC) is a very aggressive human malignancy, having a marked degree of invasiveness and no features of thyroid differentiation. It is known that either HDAC inhibitors or PARP inhibitors have antiproliferative effects on thyroid cancer cells. Therefore, in this study the possible synergy between the two types of compounds has been investigated. The ATC-derived cell line SW1736 has been treated with the HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) and the PARP inhibitor PJ34, alone or in combination. In terms of cell viability, the combination index value was always lower than 1 at various tested dosages, indicating, therefore, synergy in a wide range of doses for both compounds. Synergy was also observed in induction of apoptosis. In terms of thyroid-specific gene expression, synergy was observed for TSHR mRNA levels but not for NIS, TTF1, TTF2, and PAX8 mRNA levels. Altogether, these data suggest that the combined use of HDAC and PARP inhibitors may be a useful strategy for treatment of ATC.

Curcumin Enhances Docetaxel-Induced Apoptosis of 8505C Anaplastic Thyroid Carcinoma Cells

BACKGROUND

Anaplastic thyroid cancer (ATC) is one of the most aggressive malignancies in humans, and its progression is poorly controlled by existing therapeutic methods. Curcumin has been shown to suppress inflammation and angiogenesis. In this study, we evaluated whether curcumin could augment docetaxel-induced apoptosis of ATC cells. We also analyzed changes in nuclear factor κB (NF-κB) and cyclooxygenase-2 (COX-2) expression levels to delineate possible mechanisms of their combined action.

METHODS

ATC cells were cultured and treated with curcumin and docetaxel alone or in combination. The effects on cell viability were determined by MTS assay. Apoptosis was assessed by annexin V staining and confirmed by flow cytometric analysis. Caspase, COX-2, NF-κB levels were assayed by Western blotting.

RESULTS

Curcumin combined with docetaxel led to lower cell viability than treatment with docetaxel or curcumin alone. Annexin V staining followed by flow cytometric analysis demonstrated that curcumin treatment enhanced the docetaxel-induced apoptosis of ATC cells. Additionally, curcumin inhibited docetaxel-induced p65 activation and COX-2 expression.

CONCLUSION

We conclude that curcumin may enhance docetaxel's antitumor activity in ATC cells by interfering with NF-κB and COX-2. Our results suggest that curcumin may emerge as an attractive therapeutic candidate to enhance the antitumor activity of taxanes in ATC treatment.

PLK1 gene suppresses cell invasion of undifferentiated thyroid carcinoma through the inhibition of CD44v6, MMP-2 and MMP-9

The aim of this study was to observe the regulatory action of the polo-like kinase 1 (PLK1) gene in the invasion of anaplastic thyroid carcinoma cells and investigate its mechanisms. The expression of the PLK1 protein in 36 patients with anaplastic thyroid carcinoma was detected by immunohistochemical staining. siRNA against PLK1 was designed, synthesized and transfected into ARO cells. The effects of PLK1 siRNA on cell invasion were detected by a soft agar colony formation assay and a Transwell chamber assay. The corresponding protein was detected using western blot analysis. The expression of PLK1 in anaplastic thyroid carcinoma samples (67.5±10.6%) was significantly higher compared to that in cancer-adjacent samples (0.65%±0.12%; P<0.01). The expression of PLK1 correlated with clinical stage, lymph node metastasis and prognosis of anaplastic thyroid. The number of cell clones was reduced in a dose-dependent manner with increasing levels of siRNA and the number of cells permeating through the filter membrane decreased following transfection with siRNA. The inhibition of PLK1 caused a significant decrease in CD44v6, matrix metalloproteinase (MMP)-2 and MMP-9 (0.36±0.08, 0.12±0.03, 0.25±0.06, respectively) compared to the non-transfected group (1.15±0.18, 1.21±0.20, 1.25±0.21, respectively; P<0.01). In conclusion, the expression of PLK1 was found to be increased in anaplastic thyroid carcinoma and was correlated with clinical stage, lymph node metastasis and prognosis. Additionaly, PLK1 siRNA was found to inhibit the invasion of anaplastic thyroid carcinoma cells. Therefore, CD44v6, MMP-2 and MMP-9 are likely to be involved in the regulation of cell invasion induced by PLK1.

Prognostic factors and treatment outcomes for anaplastic thyroid carcinoma: ATC Research Consortium of Japan cohort study of 677 patients

BACKGROUND

Anaplastic thyroid carcinoma (ATC) accounts for only 1 to 2% of all thyroid carcinomas, but it is one of the most lethal neoplasms in humans. To date, most findings about ATC have been derived from single-institution studies with limited numbers of cohorts. To obtain further insights into this "orphan disease," we have established a multicenter registry, the ATC Research Consortium of Japan (ATCCJ). We analyzed prognostic factors and treatment outcomes using the large cohort database of the ATCCJ.

METHODS

Most of the Japanese centers involved in the treatment of thyroid cancer were invited to join the ATCCJ and have provided information on ATC patients treated between 1995 and 2008. The database includes 677 cases from 38 registered institutions. Survival curves were determined using Kaplan-Meier methods and were compared using the log-rank test. Cox's proportional hazards model was used for multivariate analysis.

RESULTS

Clinical varieties of ATC were classified into four types: common type (n = 547); incidental type (n = 29); anaplastic transformation at the neck (n = 95); anaplastic transformation at a distant site (n = 6). The incidental type followed by anaplastic transformation at the neck showed better outcomes than the other types. Anaplastic transformation at a distant site showed the worst outcomes. The 6-month and 1-year cause-specific survival (CSS) rates for common-type ATC were 36 and 18%, respectively. In all, 84 (15%) achieved long-term (>1 year) survival. Multivariate analysis identified age ≥70 years, presence of acute symptoms, leukocytosis (white blood cell count ≥10,000/mm(3)), large tumor >5 cm, T4b tumor, and distant metastasis as significant risk factors for lower survival. CSS rates also differed significantly depending on UICC stages, with 6-month CSSs of 60% for stage IVA, 45% for IVB, and 19% for IVC. For 36 of 69 (52%) stage IVA patients who underwent radical surgery, adjuvant therapies, including radiation therapy (RTX) and chemotherapy (CTX) did not show additional benefit statistically. Conversely, among 242 stage IVB patients, 80 (33%) underwent radical surgery. For those patients, therapies combining RTX with CTX significantly improved CSS.

CONCLUSIONS

Long-term survival is possible for selected patients with ATC. To determine the treatment strategy, UICC stage (disease extent) and other prognostic factors (e.g., biologic malignancy grade) should be considered.

Differentiated thyroid cancers: a comprehensive review of novel targeted therapies

Differentiated thyroid carcinoma (DTC) accounts for more than 90% of new thyroid cancer diagnoses, and includes papillary, follicular and Hürthle cell carcinoma. The prognosis for the vast majority of individuals diagnosed with DTC is excellent, with current treatment that includes surgery, radioactive iodine ablation and postoperative thyroid-stimulating hormone suppression. Unfortunately, the small proportion of individuals who develop radioactive iodine-resistant recurrent disease have few treatment options, and the vast majority will eventually die from their disease. Recently, several novel targets for anticancer agents have been identified and offer new hope for thyroid cancer patients diagnosed with progressive disease. In addition to targeting genes commonly altered in thyroid cancer, which include mutations in BRAF, RAS and RET, proangiogenic growth factor receptors and the sodium-iodide symporter have also been targeted. Several clinical trials evaluating tyrosine kinase and angiogenesis inhibitors for treatment of individuals diagnosed with metastatic or treatment-refractory DTC are currently underway. The objective of this review is to evaluate recent clinical trials that have studied novel targeted drugs for treatment of DTC.

CD97 amplifies LPA receptor signaling and promotes thyroid cancer progression in a mouse model

CD97, a member of the adhesion family of G-protein-coupled receptors (GPCRs), complexes with and potentiates lysophosphatidic acid (LPA) receptor signaling to the downstream effector RHOA. We show here that CD97 was expressed in a majority of thyroid cancers but not normal thyroid epithelium and that the level of CD97 expression was further elevated with progression to poorly differentiated and undifferentiated carcinoma. Intratumoral progression also showed that CD97 expression correlates with invasiveness and dedifferentiation. To determine the functional role of CD97, we produced a transgenic model of thyroglobulin promoter-driven CD97 expression. Transgenic CD97 in combination with Thrb(PV), an established mouse model of thyroid follicular cell carcinogenesis, significantly increased the occurrence of vascular invasion and lung metastasis. Expression of transgenic CD97 in thyroid epithelium led to elevated ERK phosphorylation and increased numbers of Ki67+ cells in developing tumors. In addition, tumor cell cultures derived from CD97 transgenic as compared with non-transgenic mice demonstrated enhanced, constitutive and LPA-stimulated ERK activation. In human thyroid cancer cell lines, CD97 depletion reduced RHO-GTP and decreased LPA-stimulated invasion but not EGF-stimulated invasion, further suggesting that CD97 influences an LPA-associated mechanism of progression. Consistent with the above, CD97 expression in human thyroid cancers correlated with LPA receptor and markers of aggressiveness including Ki67 and pAKT. This study shows an autonomous effect of CD97 on thyroid cancer progression and supports the investigation of this GPCR as a therapeutic target for these cancers.

Coordinated expression of galectin-3 and caveolin-1 in thyroid cancer

Galectin-3 (Gal3) is the single most accurate marker for the diagnosis of differentiated thyroid cancer (DTC). Gal3 overrides the tumour suppressor activity of caveolin-1 (Cav1) and functions in concert with Cav1 to promote focal adhesion turnover and tumour cell migration and invasion. To study their coordinated role in progression of a human cancer, we investigated the expression of Gal3 and Cav1 in specimens of human benign thyroid lesions, DTC and anaplastic thyroid cancer (ATC). Gal3 and Cav1 expression is significantly associated with DTC and ATC, but not benign nodules. Essentially all Cav1-positive DTC cancers express Gal3, supporting the synergistic activity of these two proteins in DTC progression. Similarly, coordinated elevated Gal3/Cav1 expression was observed in three DTC-derived cell lines (papillary TCP1 and KTC1 and follicular FTC133) but only one (ACT1) of five ATC-derived cell lines. Using siRNA knockdown, Gal3 and Cav1 were shown to be required for RhoA GTPase activation, stabilization of focal adhesion kinase (FAK; a measure of focal adhesion signalling and turnover) and increased migration of the DTC cell lines studied, but not the ATC cell lines, including ACT1, which expresses elevated levels of Gal3 and Cav1. Co-expression of Gal3 and Cav1 in the T238 anaplastic cell line stabilized FAK-GFP in focal adhesions. Gal3 and Cav1 therefore function synergistically to promote focal adhesion signalling, migration and progression of DTC.

CLM94, a novel cyclic amide with anti-VEGFR-2 and antiangiogenic properties, is active against primary anaplastic thyroid cancer in vitro and in vivo

CONTEXT AND OBJECTIVE

We have studied the antitumor activity of a novel cyclic amide, CLM94, with anti-vascular endothelial growth factor (VEGF) receptor-2 and antiangiogenic activity in primary anaplastic thyroid cancer (ATC) cells in vitro and in vivo.

DESIGN AND MAIN OUTCOME MEASURES

CLM94 was tested: 1) in two human cell lines (HMVEC-d, dermal microvascular endothelial cells; and 8305C, undifferentiated thyroid cancer) at 0.001-100 μm; 2) in ATC cells at the concentrations of 10, 30, and 50 μm; and 3) in an ATC cell line (AF) in CD nu/nu mice.

RESULTS

CLM94 significantly inhibited VEGF receptor-2 and epidermal growth factor receptor phosphorylation in HMVEC-d and proliferation in HMVEC-d and 8305C cells. A significant reduction of proliferation with CLM94 in ATC cells (P < 0.01, ANOVA) and a slight but significant reduction of proliferation with CLM94 30 and 50 μm in normal thyroid follicular cells (P < 0.01, ANOVA) were shown. CLM94 increased the percentage of apoptotic ATC cells dose-dependently (P < 0.001, ANOVA) and inhibited migration (P < 0.01) and invasion (P < 0.001). AF cell line was injected sc in CD nu/nu mice, and tumor masses became detectable 25 d afterward. CLM94 (40 mg/kg · d) significantly inhibited tumor growth (starting 10 d after the beginning of treatment). CLM94 significantly decreased the VEGF-A gene expression in the AF cell line and the VEGF-A protein and microvessel density in AF tumor tissues.

CONCLUSIONS

The antitumor and antiangiogenic activity of a new "cyclic amide" compound, CLM94, is very promising in ATC, opening the way to a future clinical evaluation.

Thyroid cancer cell lines: Critical models to study thyroid cancer biology and new therapeutic targets

Thyroid cancer is the most common endocrine malignancy and the incidence is rising. Currently, there are no effective treatments for patients with advanced forms of thyroid cancer. Anaplastic thyroid represents the most severe form of the disease with 95% mortality at 6 months. It is therefore critical to better understand the mechanisms involved in thyroid cancer development and progression in order to develop more effective therapeutic strategies. Cell lines derived from thyroid tumors represent a critical tool to understand the oncogenic mechanisms driving thyroid cancer, as well as preclinical tools to study the efficacy of new therapies in vitro and in vivo. For thyroid cancer, the development of new therapies has been hampered by the lack of thyroid cancer cell lines in the widely used NCI-60 panel which has been used to screen over 100,000 anti-cancer drugs. In addition, the recent discovery that ~20 out of 40 existing thyroid cancer cell lines are either redundant or misidentified with cell lines of other tissue lineages has further hampered progress in the field. Of the available cell lines, 23 were identified as unique and presumably of thyroid origin based on the expression of thyroid-specific genes. Thus, there is a great need for validated thyroid cancer cell lines representing different stages of disease in addition to distinct oncogenic mutations. New, authenticated thyroid cancer cell lines are beginning to be developed, adding to the tools available to study genes and pathways important for thyroid cancer pathogenesis. In summary, the use of validated thyroid cancer cell lines that closely recapitulate disease is critical for the discovery of new drug targets and ultimately new therapies.

Managing anaplastic thyroid carcinoma

Anaplastic thyroid cancer is one of the most lethal malignancies, with dismal prognosis, resistance to multimodal treatments and a median survival of only 5-6 months. Advances in the discovery of genetic pathway aberrations involved in this aggressive disease have been made, and multiple novel therapies targeting these pathways are undergoing clinical trials. So far, there is no single effective treatment for this disease; however, multimodal therapies with a combination of surgery, radiation and chemotherapy hold some promise. We conducted a PubMed search using the words thyroid neoplasm, anaplastic thyroid carcinoma, anaplastic thyroid cancer and anaplastic thyroid neoplasm, revealing 1673 publications. We review the pathophysiology, current treatments and advances made in identifying the alterations in genetic pathways, as well as novel therapies targeting these pathways.

Immunophenotyping of thyroid tumors identifies molecular markers altered during transformation of differentiated into anaplastic carcinoma

BACKGROUND

The objective of this study was to evaluate the change in the tumor expression profile that occurs during the transformation of differentiated thyroid cancer (DTC) into anaplastic thyroid cancer (ATC) and to evaluate an 8-marker transformation panel previously identified through evaluation of ATCs and their adjacent associated DTCs.

METHODS

Tissue microarrays were constructed from 19 ATCs and 96 DTCs (90 papillary carcinomas and 6 follicular carcinomas), and immunohistochemistry was used to evaluate the expression of 54 molecular markers. Significant associations between marker staining and cancer pathology (DTC vs ATC) were determined using contingency table and marginal homogeneity tests. A Random Forests classifier algorithm was also used to identify useful or important molecular classifiers.

RESULTS

Overall, there were 25 significantly differentially expressed markers when comparing ATCs with DTCs. These included 5 of the 8 markers that were previously identified as being altered during anaplastic transformation and 3 additional markers were also found to be highly significantly differentially expressed by ATCs and DTCs. Clustering and classification analysis based on the previously identified 8-marker transformation panel, or the 5 of these markers that were found to be most important in the current study, readily separated DTC and ATC with a high degree of accuracy.

CONCLUSIONS

The markers observed to change during thyroid cancer progression validate prior observations and represent promising molecular diagnostic or prognostic tools and identify targets for therapy of ATC.