Carlo Bellotti

The Loss of the p53 Activator HIPK2 Is Responsible for Galectin-3 Overexpression in Well Differentiated Thyroid Carcinomas

Background Galectin-3 (Gal-3) is an anti-apoptotic molecule involved in thyroid cells transformation. It is specifically overexpressed in thyroid tumour cells and is currently used as a preoperative diagnostic marker of thyroid malignancy. Gal-3 expression is downregulated by wt-p53 at the transcriptional level. In well-differentiated thyroid carcinomas (WDTCs) there is an unexplained paradoxical concomitant expression of Gal-3 and wt-p53. HIPK2 is a co-regulator of different transcription factors, and modulates basic cellular processes mainly through the activation of wt-p53. Since we demonstrated that HIPK2 is involved in p53-mediated Gal-3 downregulation, we asked whether HIPK2 deficiency might be responsible for such paradoxical Gal-3 overexpression in WDTC. Methodology/Principal Findings We analyzed HIPK2 protein and mRNA levels, as well as loss of heterozygosity (LOH) at the HIPK2 locus (7q32-34), in thyroid tissue samples. HIPK2 protein levels were high in all follicular hyperplasias (FHs) analyzed. Conversely, HIPK2 was undetectable in 91.7% of papillary thyroid carcinomas (PTCs) and in 60.0% of follicular thyroid carcinomas (FTCs). HIPK2 mRNA levels were upregulated in FH compared to normal thyroid tissue (NTT), while PTC showed mean HIPK2 mRNA levels lower than FH and, in 61.5% of cases, also lower than NTT. We found LOH at HIPK-2 gene locus in 37.5% of PTCs, 14.3% of FTCs and 18.2% of follicular adenomas. To causally link these data with Gal-3 upregulation, we performed in vitro experiments, using the PTC-derived K1 cells, in which HIPK2 expression was manipulated by RNA interference (RNAi) or plasmid-mediated overexpression. HIPK2 RNAi was associated with Gal-3 upregulation, while HIPK2 overexpression with Gal-3 downregulation. Conclusions/Significance Our results indicate that HIPK2 expression and function are impaired in WDTCs, in particular in PTCs, and that this event explains Gal-3 overexpression typically observed in these types of tumours. Therefore, HIPK2 can be considered as a new tumour suppressor gene for thyroid cancers.

Methodology and Technical Requirements of the Galectin-3 Test for the Preoperative Characterization of Thyroid Nodules

In the last decade, the &bgr;-galactosyl binding protein galectin-3 has been the object of extensive molecular, structural, and functional studies aimed to clarify its biological role in cancer. Multicenter studies also contributed to discover the potential clinical value of galectin-3 expression analysis in distinguishing, preoperatively, benign from malignant thyroid nodules. As a consequence galectin-3 is receiving significant attention as tumor marker for thyroid cancer diagnosis, but some conflicting results mostly owing to methodological problems have been published. The possibility to apply preoperatively a reliable galectin-3 test method on fine needle aspiration biopsy (FNA)-derived thyroid cells represents an important achievement. When correctly applied, the method reduces consistently the gray area of thyroid FNA cytology, contributing to avoid unnecessary thyroid surgery. Although the efficacy and reliability of the galectin-3 test method have been extensively proved in several studies, its translation in the clinical setting requires well-standardized reagents and procedures. After a decade of experimental work on galectin-3−related basic and translational research projects, the major methodological problems that may potentially impair the diagnostic performance of galectin-3 immunotargeting are highlighted and discussed in detail. A standardized protocol for a reliable galectin-3 expression analysis is finally provided. The aim of this contribution is to improve the clinical management of patients with thyroid nodules, promoting the preoperative use of a reliable galectin-3 test method as ancillary technique to conventional thyroid FNA cytology. The final goal is to decrease unnecessary thyroid surgery and its related social costs.

The electrophysiology of thyroid surgery: electrophysiologic and muscular responses with stimulation of the vagus nerve, recurrent laryngeal nerve, and external branch of the superior laryngeal nerve

Correlation of physiologically important electromyographic (EMG) waveforms with demonstrable muscle activation is important for the reliable interpretation of evoked waveforms during intraoperative neural monitoring (IONM) of the vagus nerve, recurrent laryngeal nerve (RLN), and external branch of the superior laryngeal nerve (EBSLN) in thyroid surgery.

Galectin-3: One Molecule for an Alphabet of Diseases, from A to Z

Galectin-3 (Gal-3) regulates basic cellular functions such as cell–cell and cell–matrix interactions, growth, proliferation, differentiation, and inflammation. It is not surprising, therefore, that this protein is involved in the pathogenesis of many relevant human diseases, including cancer, fibrosis, chronic inflammation and scarring affecting many different tissues. The papers published in the literature have progressively increased in number during the last decades, testifying the great interest given to this protein by numerous researchers involved in many different clinical contexts. Considering the crucial role exerted by Gal-3 in many different clinical conditions, Gal-3 is emerging as a new diagnostic, prognostic biomarker and as a new promising therapeutic target. The current review aims to extensively examine the studies published so far on the role of Gal-3 in all the clinical conditions and diseases, listed in alphabetical order, where it was analyzed.

Comparative analysis of diagnostic performance, feasibility and cost of different test-methods for thyroid nodules with indeterminate cytology

Since it is impossible to recognize malignancy at fine needle aspiration (FNA) cytology in indeterminate thyroid nodules, surgery is recommended for all of them. However, cancer rate at final histology is <30%. Many different test-methods have been proposed to increase diagnostic accuracy in such lesions, including Galectin-3-ICC (GAL-3-ICC), BRAF mutation analysis (BRAF), Gene Expression Classifier (GEC) alone and GEC+BRAF, mutation/fusion (M/F) panel, alone, M/F panel+miRNA GEC, and M/F panel by next generation sequencing (NGS), FDG-PET/CT, MIBI-Scan and TSHR mRNA blood assay. We performed systematic reviews and meta-analyses to compare their features, feasibility, diagnostic performance and cost. GEC, GEC+BRAF, M/F panel+miRNA GEC and M/F panel by NGS were the best in ruling-out malignancy (sensitivity = 90%, 89%, 89% and 90% respectively). BRAF and M/F panel alone and by NGS were the best in ruling-in malignancy (specificity = 100%, 93% and 93%). The M/F by NGS showed the highest accuracy (92%) and BRAF the highest diagnostic odds ratio (DOR) (247). GAL-3-ICC performed well as rule-out (sensitivity = 83%) and rule-in test (specificity = 85%), with good accuracy (84%) and high DOR (27) and is one of the cheapest (113 USD) and easiest one to be performed in different clinical settings. In conclusion, the more accurate molecular-based test-methods are still expensive and restricted to few, highly specialized and centralized laboratories. GAL-3-ICC, although limited by some false negatives, represents the most suitable screening test-method to be applied on a large-scale basis in the diagnostic algorithm of indeterminate thyroid lesions.

Retroperitoneal mesenchymal chondrosarcoma mimicking a large retroperitoneal sacral schwannoma

We report a case of retroperitoneal chondrosarcoma in which preoperative radiological study induced to a possible diagnosis of sacral schwannoma. A 25-year-old woman was admitted to our neurosurgical institute for a progressive sciatic pain with gait difficulties with a sudden radicular deficit with right positive Lasegue’s sign at 30°, loss of Achilles reflex, sensory deficit on right S1 dermatome, and complete motor deficit of right plantar flexion. We performed an en bloc removal of the lesion via an anterior retroperitoneal approach. We believe that the treatment of choice is radical surgical excision of the tumor with complete en-bloc removal of the lesion; postoperative radiotherapy and chemotherapy should be valuated case by case.

Minimally invasive video-assisted thyroidectomy: Ascending the learning curve

Background: Minimally invasive video-assisted thyroidectomy (MIVAT) is a technically demanding procedure and requires a surgical team skilled in both endocrine and endoscopic surgery. The aim of this report is to point out some aspects of the learning curve of the video-assisted thyroid surgery, through the analysis of our preliminary series of procedures. Patients and Methods: Over a period of 8 months, we selected 36 patients for minimally invasive video-assisted surgery of the thyroid. The patients were considered eligible if they presented with a nodule not exceeding 35 mm and total thyroid volume <20 ml; presence of biochemical and ultrasound signs of thyroiditis and pre-operative diagnosis of cancer were exclusion criteria. We analysed surgical results, conversion rate, operating time, post-operative complications, hospital stay and cosmetic outcomes of the series. Results: We performed 36 total thyroidectomy and in one case we performed a consensual parathyroidectomy. The procedure was successfully carried out in 33 out of 36 cases (conversion rate 8.3%). The mean operating time was 109 min (range: 80-241 min) and reached a plateau after 29 MIVAT. Post-operative complications included three transient recurrent nerve palsies and two transient hypocalcemias; no definitive hypoparathyroidism was registered. The cosmetic result was considered excellent by most patients. Conclusions: Advances in skills and technology allow surgeons to easily reproduce the standard open total thyroidectomy with video-assistance. Although the learning curve represents a time-consuming step, training remains a crucial point in gaining a reasonable confidence with video-assisted surgical technique.

Radioguided Surgery of Thyroid Carcinoma Recurrences

Thyroid cancer is the most common endocrine malignancy. The most frequent subtypes are differentiated thyroid cancer arising from the thyroid follicular epithelial cells and medullary thyroid cancer. The overall prognosis of patients with thyroid cancer is good, but more than one-third of patients experience recurrent disease. Patients with local recurrence in the thyroid bed or cervical lymph node metastases are usually treated with surgery, which may be complicated by the distorted anatomy due to total thyroidectomy and lymph node dissection for primary treatment. Especially in recurrent disease, exact localization of the diseased tissue or nodes may help to reduce the extent of the operative procedure. In this chapter the role of radioguided surgery for completion thyroidectomy in patients with differentiated and medullary thyroid cancer, and for reoperation in cases of recurrence, will be discussed; both iodine-guided and non-iodine-guided procedures will be considered.