Targeted therapy: A new hope for thyroid carcinomas

A comprehensive review of targeting RAF kinase in cancer

RAF kinases, particularly the BRAF isoform, play a crucial role in the MAPK/ERK signaling pathway, regulating key cellular processes such as proliferation, differentiation, and survival. Dysregulation of this pathway often caused by mutations in the BRAF gene or alterations in upstream regulators like Ras and receptor tyrosine kinases contributes significantly to cancer development. Mutations, such as BRAF-V600E, are present in a variety of malignancies, with the highest prevalence in melanoma. Targeted therapies against RAF kinases have achieved substantial success, especially in BRAF-V600E-mutant melanomas, where inhibitors like vemurafenib and dabrafenib have demonstrated remarkable efficacy, leading to improved patient outcomes. These inhibitors have also shown clinical benefits in cancers such as thyroid and colorectal carcinoma, although to a lesser extent. Despite these successes, therapeutic resistance remains a major hurdle. Resistance mechanisms, including RAF dimerization, feedback reactivation of the MAPK pathway, and paradoxical activation of ERK signaling, often lead to diminished efficacy over time, resulting in disease progression or even secondary malignancies. In response, current research is focusing on novel therapeutic strategies, including combination therapies that target multiple components of the pathway simultaneously, such as MEK inhibitors used in tandem with RAF inhibitors. Additionally, next-generation RAF inhibitors are being developed to address resistance and enhance therapeutic specificity. This review discusses the clinical advancements in RAF-targeted therapies, with a focus on ongoing efforts to overcome therapeutic resistance and enhance outcomes for cancer patients. It also underscores the persistent challenges in effectively targeting RAF kinase in oncology.

Recent Trends and Potential of Radiotherapy in the Treatment of Anaplastic Thyroid Cancer

Anaplastic thyroid cancer (ATC) is a rare but highly aggressive malignancy characterized by advanced disease at diagnosis and a poor prognosis. Despite multimodal therapeutic approaches that include surgery, radiotherapy, and chemotherapy, an optimal treatment strategy remains elusive. Current developments in targeted therapies and immunotherapy offer promising avenues for improved outcomes, particularly for BRAF-mutant patients. However, challenges remain regarding overcoming drug resistance and developing effective treatments for BRAF-wild-type tumors. This comprehensive review examines the clinical and biological features of ATC, outlines the current standards of care, and discusses recent developments with a focus on the evolving role of radiotherapy. Moreover, it emphasizes the necessity of a multidisciplinary approach and highlights the urgent need for further research to better understand ATC pathogenesis and identify new therapeutic targets. Collaborative efforts, including large-scale clinical trials, are essential for translating these findings into improved patient outcomes.

Fusion Oncogenes in Patients With Locally Advanced or Distant Metastatic Differentiated Thyroid Cancer

CONTEXT

Fusion oncogenes are involved in the underlying pathology of advanced differentiated thyroid cancer (DTC), and even the cause of radioactive iodine (RAI)-refractoriness.

OBJECTIVE

We aimed to investigation between fusion oncogenes and clinicopathological characteristics involving a large-scale cohort of patients with advanced DTC.

METHODS

We collected 278 tumor samples from patients with locally advanced (N1b or T4) or distant metastatic DTC. Targeted next-generation sequencing with a 26-gene ThyroLead panel was performed on these samples.

RESULTS

Fusion oncogenes accounted for 29.86% of the samples (72 rearrangement during transfection (RET) fusions, 7 neurotrophic tropomyosin receptor kinase (NTRK) fusions, 4 anaplastic lymphoma kinase (ALK) fusions) and occurred more frequently in pediatric patients than in their adult counterparts (P = .003, OR 2.411, 95% CI 1.329-4.311) in our cohort. DTCs with fusion oncogenes appeared to have a more advanced American Joint Committee on Cancer (AJCC)_N and AJCC_M stage (P = .0002, OR 15.47, 95% CI 2.54-160.9, and P = .016, OR 2.35, 95% CI 1.18-4.81) than those without. DTCs with fusion oncogenes were associated with pediatric radioactive iodine (RAI) refractoriness compared with those without fusion oncogenes (P = .017, OR 4.85, 95% CI 1.29-15.19). However, in adult DTCs, those with fusion oncogenes were less likely to be associated with RAI refractoriness than those without (P = .029, OR 0.50, 95% CI 0.27-0.95), owing to a high occurrence of the TERT mutation, which was the most prominent genetic risk factor for RAI refractoriness in multivariate logistic regression analysis (P < .001, OR 7.36, 95% CI 3.14-17.27).

CONCLUSION

Fusion oncogenes were more prevalent in pediatric DTCs than in their adult counterparts and were associated with pediatric RAI refractoriness, while in adult DTCs, TERT mutation was the dominant genetic contributor to RAI refractoriness rather than fusion oncogenes.

Targeted therapy for head and neck cancer: signaling pathways and clinical studies

Head and neck cancer (HNC) is malignant, genetically complex and difficult to treat and is the sixth most frequent cancer, with tobacco, alcohol and human papillomavirus being major risk factors. Based on epigenetic data, HNC is remarkably heterogeneous, and treatment remains challenging. There is a lack of significant improvement in survival and quality of life in patients with HNC. Over half of HNC patients experience locoregional recurrence or distal metastasis despite the current multiple traditional therapeutic strategies and immunotherapy. In addition, resistance to chemotherapy, radiotherapy and some targeted therapies is common. Therefore, it is urgent to explore more effective and tolerable targeted therapies to improve the clinical outcomes of HNC patients. Recent targeted therapy studies have focused on identifying promising biomarkers and developing more effective targeted therapies. A well understanding of the pathogenesis of HNC contributes to learning more about its inner association, which provides novel insight into the development of small molecule inhibitors. In this review, we summarized the vital signaling pathways and discussed the current potential therapeutic targets against critical molecules in HNC, as well as presenting preclinical animal models and ongoing or completed clinical studies about targeted therapy, which may contribute to a more favorable prognosis of HNC. Targeted therapy in combination with other therapies and its limitations were also discussed.

Molecular features of aggressive thyroid cancer

Poorly differentiated thyroid cancer (PDTC) and anaplastic thyroid cancer (ATC) have a worse prognosis with respect to well differentiated TC, and the loss of the capability of up-taking ¹³¹I is one of the main features characterizing aggressive TC. The knowledge of the genomic landscape of TC can help clinicians to discover the responsible alterations underlying more advance diseases and to address more tailored therapy. In fact, to date, the antiangiogenic multi-targeted kinase inhibitor (aaMKIs) sorafenib, lenvatinib, and cabozantinib, have been approved for the therapy of aggressive radioiodine (RAI)-resistant papillary TC (PTC) or follicular TC (FTC). Several other compounds, including immunotherapies, have been introduced and, in part, approved for the treatment of TC harboring specific mutations. For example, selpercatinib and pralsetinib inhibit mutant RET in medullary thyroid cancer but they can also block the RET fusion proteins-mediated signaling found in PTC. Entrectinib and larotrectinib, can be used in patients with progressive RAI-resistant TC harboring TRK fusion proteins. In addition FDA authorized the association of dabrafenib (BRAF^V600E inhibitor) and trametinib (MEK inhibitor) for the treatment of BRAF^V600E-mutated ATC. These drugs not only can limit the cancer spread, but in some circumstance they are able to induce the re-differentiation of aggressive tumors, which can be again submitted to new attempts of RAI therapy. In this review we explore the current knowledge on the genetic landscape of TC and its implication on the development of new precise therapeutic strategies.

Neoadjuvant famitinib and camrelizumab, a new combined therapy allowing surgical resection of the primary site for anaplastic thyroid carcinoma

BACKGROUND

Anaplastic thyroid cancer (ATC) is considered the most lethal thyroid cancer, with an overall 5-year survival rate below 10%. The FDA approved a BRAF/MEK inhibitor combination for the treatment of patients with BRAF-mutated ATC. However, effective therapeutic options for patients with wild-type BRAF are lacking.

CASE

In our phase II study, patients having advanced/metastatic solid ATCs were treated with famitinib and camrelizumab, a combination therapy involving a multi-targeted kinase inhibitor and an anti-PD-1 antibody. We report a case of a patient with locally advanced unresectable ATC who underwent this combination therapy, allowing us to perform complete surgical resection followed by post-operative radiation therapy.

CONCLISION

To the best of our knowledge, this is the first report describing the use of famitinib and camrelizumab as a neoadjuvant treatment for ATC with wild-type BRAF. Clinical trial for a novel neoadjuvant approach for ATC are currently open for enrollment.

Combination Strategies Involving Immune Checkpoint Inhibitors and Tyrosine Kinase or BRAF Inhibitors in Aggressive Thyroid Cancer

Thyroid cancer is the most common (~90%) type of endocrine-system tumor, accounting for 70% of the deaths from endocrine cancers. In the last years, the high-throughput genomics has been able to identify pathways/molecular targets involved in survival and tumor progression. Targeted therapy and immunotherapy individually have many limitations. Regarding the first one, although it greatly reduces the size of the cancer, clinical responses are generally transient and often lead to cancer relapse after initial treatment. For the second one, although it induces longer-lasting responses in cancer patients than targeted therapy, its response rate is lower. The individual limitations of these two different types of therapies can be overcome by combining them. Here, we discuss MAPK pathway inhibitors, i.e., BRAF and MEK inhibitors, combined with checkpoint inhibitors targeting PD-1, PD-L1, and CTLA-4. Several mutations make tumors resistant to treatments. Therefore, more studies are needed to investigate the patient's individual tumor mutation burden in order to overcome the problem of resistance to therapy and to develop new combination therapies.

Mutation based approaches to the treatment of anaplastic thyroid cancer

OBJECTIVE

The treatment of anaplastic thyroid cancer (ATC) has continued to rapidly evolve over time. Increased utilization of novel, personalized therapies based upon the tumour's somatic mutation status has recently been integrated. The aim of this case series is to describe a series of patients that underwent rapid genomic testing upon their diagnosis of ATC, allowing for the early integration of novel therapies.

DESIGN

A fast track pathway for genomic tumour analysis of patients with ATC was implemented at a single academic cancer hospital in January of 2020.

PATIENTS

All patients were evaluated by head and neck surgery, endocrinology, and medical oncology upon diagnosis of ATC.

MEASUREMENTS

Genetic work-up was completed, which prompted a recommendation for dual BRAF/MEK inhibition with dabrafenib and trametinib for tumours with BRAF V600E mutation. For patients whose tumours were BRAF V600E wild-type, pembrolizumab with lenvatinib was offered.

RESULTS

A total of four patients were included in this series. Two patients (50%) had tumours that were BRAF V600E positive. Among patients that were BRAF V600E positive, both patients initiated urgent dabrafenib and trametinib dual tyrosine kinase inhibitor (TKI) therapy; with one patient demonstrating near-complete clinical response allowing for posttreatment surgery, while the other demonstrated decreased tumour burden. Among patients who were BRAF V600E wild-type, lenvatinib and pembrolizumab were recommended off-label; one patient demonstrated decreased tumour burden, but developed severe pure red cell aplasia, while the other patient is demonstrating an early clinical response.

CONCLUSIONS

The integration of early genomic analysis and personalized neoadjuvant TKI therapy into the treatment of ATC can greatly benefit patient care outcomes and optimize tumour control.

Advances in pharmacotherapy for advanced thyroid cancer of follicular origin (PTC, FTC). New approved drugs and future therapies

INTRODUCTION

The most common altered signaling found in aggressive iodine-refractory Thyroid cancer derived from follicular cells (RAI-TC) are RTK, MAPK, PI3K, WNT, BRAF, RAS, RET, and TP53. Tyrosine Kinase Inhibitors (TKI) are multi-kinase inhibitors able to act against different pathways, that elicit an anti-neoplastic activity.

AREAS COVERED

The aim of this paper is to review recent novel molecular therapies of RAI-TC. Recently, sorafenib and lenvatinib, have been approved for the treatment of aggressive RAI-TC. Other studies are evaluating vandetanib and selumetinib in RAI-TC. Furthermore, preliminary studies have evaluated dabrafenib, and vemurafenib in BRAF mutated RAI-TC patients to re-induce 131-iodine uptake. The interplay between cells of the immune system and cancer cells can be altered by immune checkpoints inhibitors. The expression of PDL1 in RAI-TC was related to tumor recurrence and poor survival. Several clinical trials are investigating a combination of different therapies, such as lenvatinib and pembrolizumab.

EXPERT OPINION

Mechanisms of resistance to TKIs inhibitors can be of intrinsic or acquired origin. An acquired resistance to lenvatinib, or sorafenib can be due to upregulation of FGFR; therefore anti-FGFR agents are evaluated. A new strategy is to combine TKIs with immunotherapy. Several studies are evaluating lenvatinib and pembrolizumab in RAI-TC patients.

Advances in targeted therapy for anaplastic thyroid carcinoma

Anaplastic thyroid carcinoma (ATC) is a highly malignant and aggressive thyroid malignancy with rapid onset and poor prognosis. There is no effective treatment for ATC yet. Molecular targeted therapy provides a new idea for ATC treatment. Tyrosine kinase inhibitor lenvatinib has potential in treating ATC patients with favorable efficacy in clinical trials. The effectiveness of the v-raf murine sarcoma viral oncogene homologue B1 () gene inhibitor dabrafenib in combination with trametinib for the treatment of positive ATC patients has been demonstrated in clinical trials. The has proposed dabrafenib in combination with trametinib as the preferred modality for the treatment of patients with positive ATC. The immune checkpoint inhibitor pembrolizumab can be applied to treat thyroid cancer with high tumor mutational load and may be considered as the preferred modality for the treatment of ATC patients with high programmed death ligand-1 expression. The mammalian target of rapamycin pathway inhibitors, peroxisome proliferators-activated receptor γ agonists, endothelial growth factor receptors-targeting monoclonal antibody cetuximab and novel vascular blocker fosbretabulin are still in the clinical research stage, which are expected to provide new directions for the development of novel targeted drugs. This article reviews the current research progress on targeted drugs for the treatment of ATC.

Circ_0011058 facilitates proliferation, angiogenesis and radioresistance in papillary thyroid cancer cells by positively regulating YAP1 via acting as miR-335-5p sponge

BACKGROUND

Circular RNAs (circRNAs) are reported to be associated with multiple biological processes in human cancers. However, there are still numerous circRNAs whose functions remain unclear. The aim of this study was to investigate the role of circ_0011058 in papillary thyroid cancer (PTC).

METHODS

Quantitative real-time PCR (qPCR) was utilized to detect the expression of circ_0011058, microRNA-335-5p (miR-335-5p) and Yes-associated Protein 1 (YAP1). Cell proliferation was detected using cell counting kit-8 (CCK-8) assay and EdU assay. Cell apoptosis was detected by flow cytometry assay. Angiogenesis ability was assessed using tube formation assay. The expression of angiogenesis-related proteins and YAP1 protein was detected by western blot. Radioresistance was examined using colony formation assay. The binding relationship between miR-335-5p and circ_0011058 or YAP1 was verified by dual-luciferase reporter assay, pull-down assay and RIP assay. Xenograft models were constructed to ensure the role of circ_0011058.

RESULTS

Circ_0011058 expression was aberrantly elevated in PTC tissues and cells. The downregulation of circ_0011058 suppressed proliferation, angiogenesis and radioresistance in PTC cells. MiR-335-5p was defined as a target of circ_0011058, and miR-335-5p inhibition reversed the effects of circ_0011058 downregulation. In addition, YAP1 was a target of miR-335-5p, and circ_0011058 positively regulated YAP1 expression by targeting miR-335-5p. MiR-335-5p restoration inhibited proliferation, angiogenesis and radioresistance in PTC cells, while YAP1 overexpression abolished these effects. Animal study showed that circ_0011058 knockdown inhibited tumor growth in vivo.

CONCLUSION

Circ_0011058 promoted PTC cell proliferation, angiogenesis and radioresistance by upregulating YAP1 via acting as miR-335-5p sponge.

Silencing long non-coding RNA DLX6-AS1 or restoring microRNA-193b-3p enhances thyroid carcinoma cell autophagy and apoptosis via depressing HOXA1

Long non‐coding RNA DLX6 antisense RNA 1 (DLX6‐AS1) lists a critical position in thyroid carcinoma (TC) development. However, the overall comprehension about DLX6‐AS1, microRNA (miR)‐193b‐3p and homeobox A1 (HOXA1) in TC is not thoroughly enough. Concerning to this, this work is pivoted on DLX6‐AS1/miR‐193b‐3p/HOXA1 axis in TC cell growth and autophagy. TC tissues and adjacent normal thyroid tissues were collected, in which expression of DLX6‐AS1, miR‐193b‐3p and HOXA1 was tested, together with their interactions. TC cells were transfected with DLX6‐AS1/miR‐193b‐3p‐related oligonucleotides or plasmids to test cell growth and autophagy. Tumorigenesis in nude mice was observed. DLX6‐AS1 and HOXA1 were up‐regulated, and miR‐193b‐3p was down‐regulated in TC. Depleted DLX6‐AS1 or restored miR‐193b‐3p disturbed cell growth and promoted autophagy. DLX6‐AS1 targeted miR‐193b‐3p and positively regulated HOXA1. miR‐193b‐3p inhibition mitigated the impaired tumorigenesis induced by down‐regulated DLX6‐AS1. Tumorigenesis in nude mice was consistent with that in cells. It is clear that DLX6‐AS1 depletion hinders TC cell growth and promotes autophagy via up‐regulating miR‐193b‐3p and down‐regulating HOXA1.

Lenvatinib: an investigational agent for the treatment of differentiated thyroid cancer

INTRODUCTION

Differentiated thyroid cancer (DTC; >90% of all TCs) derives from follicular cells. Surgery is the main therapeutic strategy, and radioiodine (RAI) is administered after thyroidectomy. When DTC progresses, it does not respond to RAI and thyroid-stimulating hormone (TSH)-suppressive thyroid hormone treatment, and other therapies (i.e. surgery, external beam radiation therapy and chemotherapy) do not lead to a better survival. Thanks to the understanding of the molecular pathways involved in TC progression, important advances have been done. Lenvatinib is a multitargeted tyrosine kinase inhibitor of VEGFR1-3, FGFR1-4, PDGFRα, RET, and KIT signaling networks implicated in tumor angiogenesis, approved in locally recurrent or metastatic, progressive, RAI-refractory DTC. Unmet needs regarding the patient clinical therapy responsiveness in aggressive RAI-refractory DTC still remain.

AREAS COVERED

We provide an overview from the literature of in vitro, in vivo and real-life studies regarding lenvatinib as an investigational agent for the treatment of aggressive TC.

EXPERT OPINION

According to the SELECT trial, the treatment should be initiated with a dosage of 24 mg/day, subsequently decreasing it in relation to the side effects. The decision making process in patients with aggressive RAI-refractory DTC should be personalized and the potential toxicity should be properly managed.

Molecular targets of tyrosine kinase inhibitors in thyroid cancer

Thyroid cancer (TC) is the eighth most frequently diagnosed cancer worldwide with a rising incidence in the past 20 years. Surgery is the primary strategy of therapy for patients with medullary TC (MTC) and differentiated TC (DTC). In DTC patients, radioactive iodine (RAI) is administered after thyroidectomy. Neck ultrasound, basal and thyroid-stimulating hormone-stimulated thyroglobulin are generally performed every three to six months for the first year, with subsequent intervals depending on initial risk assessment, for the detection of possible persistent/recurrent disease during the follow up. Distant metastases are present at the diagnosis in ∼5 % of DTC patients; up to 15 % of patients have recurrences during the follow up, with a survival reduction (70 %-50 %) at 10-year. During tumor progression, the iodide uptake capability of DTC cancer cells can be lost, making them refractory to RAI, with a negative impact on the prognosis. Significant advances have been done recently in our understanding of the molecular pathways implicated in the progression of TCs. Several drugs have been developed, which inhibit signaling kinases or oncogenic kinases (BRAF^V600E, RET/PTC), such as those associated with Platelet-Derived Growth Factor Receptor and Vascular Endothelial Growth Factor Receptor. Tyrosine kinase receptors are involved in cancer cell proliferation, angiogenesis, and lymphangiogenesis. Several tyrosine kinase inhibitors (TKIs) are emerging as new treatments for DTC, MTC and anaplastic TC (ATC), and can induce a clinical response and stabilize the disease. Lenvatinib and sorafenib reached the approval for RAI-refractory DTC, whereas cabozantinib and vandetanib for MTC. These TKIs extend median progression-free survival, but do not increase the overall survival. Severe side effects and drug resistance can develop in TC patients treated with TKIs. Additional studies are needed to identify a potential effective targeted therapy for aggressive TCs, according to their molecular characterization.

Novel treatments for anaplastic thyroid carcinoma

Anaplastic thyroid cancer (ATC) is one of the deadliest human cancers and it is less than 2% of thyroid carcinomas (TCs). The standard treatment of ATC includes surgical debulking, accelerated hyperfractionated external beam radiation therapy (EBRT), and chemotherapy, in particular with cisplatin or doxorubicin, achieving about 10 months of median survival. Since ATC is a rare and aggressive tumor, it is still challenging to predict the patient clinical therapy responsiveness. Several genetic mutations have been described in ATC, involved in different molecular pathways linked to tumor progression, and novel therapies acting on these molecular pathways have been investigated, to improve the quality of life in these patients. Here we review the new targeted therapy of ATC. We report interesting results obtained with molecules targeting different pathways: angiogenesis (vandetanib, combretastatin, sorafenib, lenvatinib, sunitinib, CLM94, CLM3, etc.); EGFR (gefitinib, docetaxel); BRAF (dabrafenib/trametinib, vemurafenib); PPARγ agonists (rosiglitazone, pioglitazone, efatutazone); PD-1 and PD-L1 (pembrolizumab); TERT. To escape resistance to monotherapies, the evaluation of combination strategies with radiotherapy, chemotherapy, or targeted drugs is ongoing. The results of clinical trials with dabrafenib and trametinib led to the approval from FDA of this combination for patients with BRAF V600E mutated ATC with locally advanced, unresectable, or metastatic ATC. The anti-PD-L1 antibody immunotherapy, alone or combined with a BRAF inhibitor, has been shown also promising in the treatment of ATC. Furthermore, to increase the therapeutic success and not to use ineffective or even harmful treatments, a real tailored therapy should be pursued, and this can be achieved thanks to the new available genomic analysis methods and to the possibility to test in vitro novel treatments directly in primary cells from each ATC patient. Exploring new treatment strategies is mandatory to improve the survival of these patients, guaranteeing a good quality of life.

Genetic alterations in anaplastic thyroid carcinoma and targeted therapies

Thyroid cancer is the most common type of endocrine malignancy, and its incidence is increasing. Anaplastic thyroid cancer (ATC), referring to undifferentiated subtypes, is considered to be aggressive and associated with poor prognosis. Conventional therapies, including surgery, chemotherapy and radioiodine therapy, have been used for ATC, but these do not provide any significant reduction of the overall mortality rate. The tumorigenesis, development, dedifferentiation and metastasis of ATC are closely associated with the activation of various tyrosine cascades and inactivation of tumor suppressor genes, including B-Raf proto-oncogene, serine/threonine kinase^V600E, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit α,tumor protein 53 mutations and telomerase reverse transcriptase mutation. These pathways exert their functions individually or through a complex network. Identification of these mutations may provide a deeper understanding of ATC. A variety of tyrosine kinase inhibitors have been successfully employed for controlling ATC growth in vitro and in xenografts. Certain novel compounds are still in clinical trials. Multi-kinase inhibitors provide a novel approach with great potential. This systematic review determined the prevalence of the major genetic alterations and their inhibitors in ATC.

The Role of ATP-Binding Cassette Transporters in the Chemoresistance of Anaplastic Thyroid Cancer: A Systematic Review

Anaplastic thyroid cancer (ATC) is an aggressive type of thyroid cancer with a high mortality rate. Cytotoxic drugs are among the treatment modalities usually used for ATC treatment. However, systemic chemotherapies for ATC have not been shown to have remarkable efficacy. ATP-binding cassette (ABC) transporters have been suggested as a possible mechanism in ATC resistance to chemotherapy. This systematic review was aimed to define the possible roles of ABC transporters in ATC resistance to chemotherapy. Numerous databases, including Scopus, Web of Science, PubMed, Cochrane Library, Ovid, ProQuest, and EBSCO, were searched for papers published since 1990, with predefined keywords. The literature searches were updated twice, in 2015 and 2017. All identified articles were reviewed, and 14 papers that met the inclusion criteria were selected. In the eligible studies, the roles of 10 out of 49 ABC transporters were evaluated; among them, three pumps (ABCB1, ABCC1, and ABCG2) were the most studied transporters in ATC samples. ABCC1 and ABCG2 had the highest expression rates in ATC, and ABCB1 ranked second among the inspected transporters. In conclusion, ABC transporters are the major determinants of ATC resistance to chemotherapy. By identifying these transporters, we can tailor the best treatment approach for patients with ATC. Additional studies are needed to define the exact role of each ABC transporter and other mechanisms in ATC drug resistance.

Thyroid cancer management: from a suspicious nodule to targeted therapy

Thyroid nodules are very common, and their frequency is four to five times higher in women than in men. Most of them are benign, with only a very little percentage revealing a malignant neoplasm. About 50% of thyroid nodules are detected by self-palpation of neck, whereas the other 50% are diagnosed by neck ultrasonography and following fine-needle aspiration. Management of thyroid nodules is very difficult, because benign nodules are prevalent, whereas thyroid carcinoma is uncommon, representing only 1% of all malignancies. A standard diagnostic approach is represented by 'first-level' exams, consisting in neck ultrasonography and serum thyroid-stimulating hormone measurement, followed, only for nodules that are suspicious of malignancy, by 'second-level' exams, consisting of fine-needle aspiration and mutational test, which does detect particular DNA mutations present only in malignant cells. In this review, we will analyze the genetics of thyroid cancer and its heterogeneity, and we will briefly describe the current available diagnostic and therapeutic approaches.

The Network of Non-coding RNAs in Cancer Drug Resistance

Non-coding RNAs (ncRNAs) have been implicated in most cellular functions. The disruption of their function through somatic mutations, genomic imprinting, transcriptional and post-transcriptional regulation, plays an ever-increasing role in cancer development. ncRNAs, including notorious microRNAs, have been thus proposed to function as tumor suppressors or oncogenes, often in a context-dependent fashion. In parallel, ncRNAs with altered expression in cancer have been reported to exert a key role in determining drug sensitivity or restoring drug responsiveness in resistant cells. Acquisition of resistance to anti-cancer drugs is a major hindrance to effective chemotherapy and is one of the most important causes of relapse and mortality in cancer patients. For these reasons, non-coding RNAs have become recent focuses as prognostic agents and modifiers of chemo-sensitivity. This review starts with a brief outline of the role of most studied non-coding RNAs in cancer and then highlights the modulation of cancer drug resistance via known ncRNAs based mechanisms. We identified from literature 388 ncRNA-drugs interactions and analyzed them using an unsupervised approach. Essentially, we performed a network analysis of the non-coding RNAs with direct relations with cancer drugs. Within such a machine-learning framework we detected the most representative ncRNAs-drug associations and groups. We finally discussed the higher integration of the drug-ncRNA clusters with the goal of disentangling effectors from downstream effects and further clarify the involvement of ncRNAs in the cellular mechanisms underlying resistance to cancer treatments.

Gene Fusions in Thyroid Cancer

BACKGROUND

Gene fusions are known in many cancers as driver or passenger mutations. They play an important role in both the etiology and pathogenesis of cancer and are considered as potential diagnostic and prognostic markers and possible therapeutic targets. The spectrum and prevalence of gene fusions in thyroid cancer ranges from single cases up to 80%, depending on the specific type of cancer. During last three years, massive parallel sequencing technologies have revealed new fusions and allowed detailed characteristics of fusions in different types of thyroid cancer.

SUMMARY

This article reviews all known fusions and their prevalence in papillary, poorly differentiated and anaplastic, follicular, and medullary carcinomas. The mechanisms of fusion formation are described. In addition, the mechanisms of oncogenic transformation, such as altered gene expression, forced oligomerization, and subcellular localization, are given.

CONCLUSION

The prognostic value and perspectives of the utilization of gene fusions as therapeutic targets are discussed.

Enhanced cytotoxic effect of camptothecin nanosponges in anaplastic thyroid cancer cells in vitro and in vivo on orthotopic xenograft tumors

Anaplastic carcinoma of the thyroid (ATC) is a lethal human malignant cancer with median survival of 6 months. To date, no treatment has substantially changed its course, which makes urgent need for the development of novel drugs or novel formulations for drug delivery. Nanomedicine has enormous potential to improve the accuracy of cancer therapy by enhancing availability and stability, decreasing effective doses and reducing side effects of drugs. Camptothecin (CPT) is an inhibitor of DNA topoisomerase-I with several anticancer properties but has poor solubility and a high degradation rate. Previously, we reported that CPT encapsulated in β-cyclodextrin-nanosponges (CN-CPT) increased solubility, was protected from degradation and inhibited the growth of prostate tumor cells both in vitro and in vivo. The aim of this study was to extend that work by assessing the CN-CPT effectiveness on ATC both in vitro and in vivo. Results showed that CN-CPT significantly inhibited viability, clonogenic capacity and cell-cycle progression of ATC cell lines showing a faster and enhanced effect compared to free CPT. Moreover, CN-CPT inhibited tumor cell adhesion to vascular endothelial cells, migration, secretion of pro-angiogenic factors (IL-8 and VEGF-α), expression of β-PIX, belonging to the Rho family activators, and phosphorylation of the Erk1/2 MAPK. Finally, CN-CPT significantly inhibited the growth, the metastatization and the vascularization of orthotopic ATC xenografts in SCID/beige mice without apparent toxic effects in vivo. This work extends the previous insight showing that β-cyclodextrin-nanosponges are a promising tool for the treatment of ATC.

Novel treatment options for anaplastic thyroid cancer

Several genetic alterations have been identified in different molecular pathways ofanaplastic thyroid cancer (ATC) and associated with tumor aggressiveness and progression (BRAF, p53,RAS, EGFR, VEGFR-1, VEGFR-2, etc). New drugs targeting these molecular pathways have beenrecently evaluated in ATC. Areas covered: We review the new targeted therapies of ATC. Interesting results have been reported with molecules targeting different pathways, as: a-BRAF (dabrafenib/trametinib, vemurafenib); b-angiogenesis (sorafenib, combretastatin, vandetanib, sunitinib, lenvatinib, CLM3, etc); c-EGFR (gefitinib); d- PPARγ agonists (rosiglitazone, pioglitazone, efatutazone). In patients with ATC treated with lenvatinib, a median overall survival of 10.6 (3.8-19.8) months was reported. In order to bypass the resistance to the single drug, the capability of targeted drugs to synergize with radiation, or chemotherapy, or other targeted drugs is explored. Expert commentary: New, affordable and individual genomic analysis combined with the opportunity to test these new treatments in primary cell cultures from every ATC patient in vitro, may permit the personalization of therapy. Increasing the therapeutic effectiveness and avoiding the use of ineffective drugs. The identification of new treatments is necessary, to extend life duration guaranteing a good quality of life. To bypass the resistance to asingle drug, the capability of targeted drugs to synergize with radiation, or chemotherapy, or othertargeted drugs is explored. Moreover, new affordable individual genomic analysis and the opportunity totest these novel treatments in primary cell cultures from every ATC patient in vitro, might permit topersonalize the therapy, increasing the therapeutic effectiveness and avoiding the use of ineffectivedrugs.

Development and clinical application of an integrative genomic approach to personalized cancer therapy

BACKGROUND

Personalized therapy provides the best outcome of cancer care and its implementation in the clinic has been greatly facilitated by recent convergence of enormous progress in basic cancer research, rapid advancement of new tumor profiling technologies, and an expanding compendium of targeted cancer therapeutics.

METHODS

We developed a personalized cancer therapy (PCT) program in a clinical setting, using an integrative genomics approach to fully characterize the complexity of each tumor. We carried out whole exome sequencing (WES) and single-nucleotide polymorphism (SNP) microarray genotyping on DNA from tumor and patient-matched normal specimens, as well as RNA sequencing (RNA-Seq) on available frozen specimens, to identify somatic (tumor-specific) mutations, copy number alterations (CNAs), gene expression changes, gene fusions, and also germline variants. To provide high sensitivity in known cancer mutation hotspots, Ion AmpliSeq Cancer Hotspot Panel v2 (CHPv2) was also employed. We integrated the resulting data with cancer knowledge bases and developed a specific workflow for each cancer type to improve interpretation of genomic data.

RESULTS

We returned genomics findings to 46 patients and their physicians describing somatic alterations and predicting drug response, toxicity, and prognosis. Mean 17.3 cancer-relevant somatic mutations per patient were identified, 13.3-fold, 6.9-fold, and 4.7-fold more than could have been detected using CHPv2, Oncomine Cancer Panel (OCP), and FoundationOne, respectively. Our approach delineated the underlying genetic drivers at the pathway level and provided meaningful predictions of therapeutic efficacy and toxicity. Actionable alterations were found in 91 % of patients (mean 4.9 per patient, including somatic mutations, copy number alterations, gene expression alterations, and germline variants), a 7.5-fold, 2.0-fold, and 1.9-fold increase over what could have been uncovered by CHPv2, OCP, and FoundationOne, respectively. The findings altered the course of treatment in four cases.

CONCLUSIONS

These results show that a comprehensive, integrative genomic approach as outlined above significantly enhanced genomics-based PCT strategies.

MicroRNA-375/SEC23A as biomarkers of the in vitro efficacy of vandetanib

In this study, we performed microRNA (miRNA) expression profiling on a large series of sporadic and hereditary forms of medullary thyroid carcinomas (MTC). More than 60 miRNAs were significantly deregulated in tumor vs adjacent non-tumor tissues, partially overlapping with results of previous studies. We focused our attention on the strongest up-regulated miRNA in MTC samples, miR-375, the deregulation of which has been previously observed in a variety of human malignancies including MTC. We identified miR-375 targets by combining gene expression signatures from human MTC (TT) and normal follicular (Nthy-ori 3-1) cell lines transfected with an antagomiR-375 inhibitor or a miR-375 mimic, respectively, and from an in silico analysis of thyroid cell lines of Cancer Cell Line Encyclopedia datasets. This approach identified SEC23A as a bona fide miR-375 target, which we validated by immunoblotting and immunohistochemistry of non-tumor and pathological thyroid tissue. Furthermore, we observed that miR-375 overexpression was associated with decreased cell proliferation and synergistically increased sensitivity to vandetanib, the clinically relevant treatment of metastatic MTC. We found that miR-375 increased PARP cleavage and decreased AKT phosphorylation, affecting both cell proliferation and viability. We confirmed these results through SEC23A direct silencing in combination with vandetanib, highlighting the importance of SEC23A in the miR-375-associated increased sensitivity to vandetanib.Since the combination of increased expression of miR-375 and decreased expression of SEC23A point to sensitivity to vandetanib, we question if the expression levels of miR-375 and SEC23A should be evaluated as an indicator of eligibility for treatment of MTC patients with vandetanib.

FTY720 (Fingolimod) attenuates basal and sphingosine-1-phosphate-evoked thyroid cancer cell invasion

The bioactive lipid sphingosine-1-phosphate (S1P) is a potent inducer of ML-1 thyroid cancer cell migration and invasion. It evokes migration and invasion by activating S1P receptor 1 and 3 (S1P1,3) and downstream signaling intermediates as well as through cross-communication with vascular endothelial growth factor receptor 2 (VEGFR2). However, very little is known about the role of S1P receptors in thyroid cancer. Furthermore, the currently used treatments for thyroid cancer have proven to be rather unsuccessful. Thus, due to the insufficiency of the available treatments for thyroid cancer, novel and targeted therapies are needed. The S1P receptor functional antagonist FTY720, an immunosuppressive drug currently used for treatment of multiple sclerosis, has shown promising effects as an inhibitor of cancer cell proliferation and invasion. In this study, we investigated the effect of FTY720 on invasion and proliferation of several thyroid cancer cell lines. We present evidence that FTY720 attenuated basal as well as S1P-evoked invasion of these cell lines. Furthermore, FTY720 potently downregulated S1P1, protein kinase Cα(PKCα), PKCβI, and VEGFR2. It also attenuated S1P-evoked phosphorylation of ERK1/2. Our results also showed that FTY720 attenuated S1P-induced MMP2 intracellular expression, S1P-induced secretion of MMP2 and MMP9, and decreased basal MMP2 and MMP9 activity. Moreover, in FTY720-treated cells, proliferation was attenuated, p21 and p27 were upregulated, and the cells were arrested in the G1 phase of the cell cycle. FTY720 attenuated cancer cell proliferation in the chick embryo chorioallantoic membrane assay. Thus, we suggest that FTY720 could be beneficial in the treatment of thyroid cancer.

Targeting lipid metabolism for the treatment of anaplastic thyroid carcinoma

INTRODUCTION

Anaplastic thyroid carcinoma (ATC) is the rarest subtype of thyroid cancer; however, it disproportionately accounts for a large percentage of all thyroid cancer-related deaths and is considered one of the most lethal solid tumors in humans, having a median survival of only a few months upon diagnosis. Although a variety of treatment options are available including surgery, radiation and targeted therapies, response rates are low, due in part to the drug-resistant nature of this disease; therefore, new avenues for therapeutic intervention are surely needed. Recent investigation into the metabolic profile of ATC has revealed a tumor-specific dependency for increased de novo lipogenesis, offering new insight into the molecular mechanisms that govern disease initiation and progression.

AREAS COVERED

Herein we summarize known oncogenic signaling pathways and current therapeutic strategies for the treatment of ATC. We further discuss the unique expression pattern of lipid metabolism constituents in this disease. Additionally, the current literature correlating aberrant lipogenesis with carcinogenesis is reviewed, and the implications of targeting this pathway as an innovative approach for treating ATC and other malignancies are discussed. As stearoyl-CoA desaturase (SCD) is the most differentially expressed constituent of lipid metabolism in ATC, an additional focus on this enzyme as a novel therapeutic target is applied.

EXPERT OPINION

This section is used to summarize the current research efforts underway in defining the role of lipid metabolism specifically in thyroid carcinoma. Included is a brief summary of lipid metabolism factors for which inhibitors have been generated and are under current investigation as anti-cancer agents. Finally, research limitations regarding the use of these inhibitors against components of this pathway are discussed.

Protecting the normal in order to better kill the cancer

Chemotherapy is the only option for oncologists when a cancer has widely spread to different body sites. However, almost all currently available chemotherapeutic drugs will eventually encounter resistance after their initial positive effect, mainly because cancer cells develop genetic alterations, collectively coined herein as mutations, to adapt to the therapy. Some patients may still respond to a second chemo drug, but few cases respond to a third one. Since it takes time for cancer cells to develop new mutations and then select those life-sustaining ones via clonal expansion, "run against time for mutations to emerge" should be a crucial principle for treatment of those currently incurable cancers. Since cancer cells constantly change to adapt to the therapy whereas normal cells are stable, it may be a better strategy to shift our focus from killing cancer cells per se to protecting normal cells from chemotherapeutic toxicity. This new strategy requires the development of new drugs that are nongenotoxic and can quickly, in just hours or days, kill cancer cells without leaving the still-alive cells with time to develop mutations, and that should have their toxicities confined to only one or few organs, so that specific protections can be developed and applied.

Follicular thyroid carcinoma with skull metastases

Thyroid carcinoma with distant metastases at initial presentation, is uncommon. Skull metastases occur very rarely, with a reported incidence of 2.5-5.8%. Here we report two cases of follicular thyroid cancer with skull involvement, and describe the diagnostic and therapeutic approach to metastatic thyroid cancer. We present the cases of a 70-year-old female and a 74-year-old female who presented with painless, large slow-growing masses of the skull. The patients underwent surgical excision of the skull masses, which were histologically diagnosed as metastatic follicular thyroid cancer, and total thyroidectomy, which confirmed the diagnosis of follicular thyroid carcinoma. They were treated with radioiodine and suppressive levothyroxine, which achieved local control of the disease. Management of metastatic thyroid cancer, requires a multidisciplinary approach and multimodality treatment. Distant metastases should be surgically removed whenever possible. Initial aggressive treatment is crucial in the management of metastatic thyroid carcinoma, providing the best chance to prolong patient survival.