Changes in antioxidant status and DNA repair capacity are corroborated with molecular alterations in malignant thyroid tissue of patients with papillary thyroid cancer.

Introduction: Papillary thyroid cancer (PTC) accounts for approximately 80% of all thyroid cancer cases. The mechanism of PTC tumourigenesis is not fully understood, but oxidative imbalance is thought to play a role. To gain further insight, this study evaluated antioxidant status, DNA repair capacity and genetic alterations in individuals diagnosed with benign thyroid lesion in one lobe (BTG) and PTC lesion in another. Methods: Individuals with coexisting BTG and PTC lesions in their thyroid lobes were included in this study. Reactive oxygen species (ROS) level, ABTS radical scavenging activity, ferric reducing antioxidant capacity, glutathione peroxidase and superoxide dismutase activities were measured in the thyroid tissue lysate. The expression of selected genes and proteins associated with oxidative stress defence and DNA repair were analysed through quantitative real-time PCR and Western blotting. Molecular alterations in genomic DNA were analysed through whole-exome sequencing and the potentially pathogenic driver genes filtered through Cancer-Related Analysis of Variants Toolkit (CRAVAT) analysis were subjected to pathway enrichment analysis using Metascape. Results: Significantly higher ROS level was detected in the PTC compared to the BTG lesions. The PTC lesions had significantly higher expression of GPX1, SOD2 and OGG1 but significantly lower expression of CAT and PRDX1 genes than the BTG lesions. Pathway enrichment analysis identified "regulation of MAPK cascade," "positive regulation of ERK1 and ERK2 cascade" and "negative regulation of reactive oxygen species metabolic process" to be significantly enriched in the PTC lesions only. Four pathogenic genetic variants were identified in the PTC lesions; BRAF V600E, MAP2K7-rs2145142862, BCR-rs372013175 and CD24 NM_001291737.1:p.Gln23fs while MAP3K9 and G6PD were among 11 genes that were mutated in both BTG and PTC lesions. Conclusion: Our findings provided further insight into the connection between oxidative stress, DNA damage, and genetic changes associated with BTG-to-PTC transformation. The increased oxidative DNA damage due to the heightened ROS levels could have heralded the BTG-to-PTC transformation, potentially through mutations in the genes involved in the MAPK signalling pathway and stress-activated MAPK/JNK cascade. Further in-vitro functional analyses and studies involving a larger sample size would need to be carried out to validate the findings from this pilot study.

Whole-exome sequencing and bioinformatic analyses revealed differences in gene mutation profiles in papillary thyroid cancer patients with and without benign thyroid goitre background.

Background: Papillary thyroid cancer (PTC) is the most common thyroid malignancy. Concurrent presence of cytomorphological benign thyroid goitre (BTG) and PTC lesion is often detected. Aberrant protein profiles were previously reported in patients with and without BTG cytomorphological background. This study aimed to evaluate gene mutation profiles to further understand the molecular mechanism underlying BTG, PTC without BTG background and PTC with BTG background. Methods: Patients were grouped according to the histopathological examination results: (i) BTG patients (n = 9), (ii) PTC patients without BTG background (PTCa, n = 8), and (iii) PTC patients with BTG background (PTCb, n = 5). Whole-exome sequencing (WES) was performed on genomic DNA extracted from thyroid tissue specimens. Nonsynonymous and splice-site variants with MAF of ≤ 1% in the 1000 Genomes Project were subjected to principal component analysis (PCA). PTC-specific SNVs were filtered against OncoKB and COSMIC while novel SNVs were screened through dbSNP and COSMIC databases. Functional impacts of the SNVs were predicted using PolyPhen-2 and SIFT. Protein-protein interaction (PPI) enrichment of the tumour-related genes was analysed using Metascape and MCODE algorithm. Results: PCA plots showed distinctive SNV profiles among the three groups. OncoKB and COSMIC database screening identified 36 tumour-related genes including BRCA2 and FANCD2 in all groups. BRAF and 19 additional genes were found only in PTCa and PTCb. "Pathways in cancer", "DNA repair" and "Fanconi anaemia pathway" were among the top networks shared by all groups. However, signalling pathways related to tyrosine kinases were the most significantly enriched in PTCa while "Jak-STAT signalling pathway" and "Notch signalling pathway" were the only significantly enriched in PTCb. Ten SNVs were PTC-specific of which two were novel; DCTN1 c.2786C>G (p.Ala929Gly) and TRRAP c.8735G>C (p.Ser2912Thr). Four out of the ten SNVs were unique to PTCa. Conclusion: Distinctive gene mutation patterns detected in this study corroborated the previous protein profile findings. We hypothesised that the PTCa and PTCb subtypes differed in the underlying molecular mechanisms involving tyrosine kinase, Jak-STAT and Notch signalling pathways. The potential applications of the SNVs in differentiating the benign from the PTC subtypes requires further validation in a larger sample size.

Salmonella thyroid abscess-two case reports.

Acute suppurative thyroiditis account for <1% of thyroid diseases and is uncommon because of the gland's encapsulation, iodine-rich environment, good vascular supply and extensive lymphatic drainage. It has been reported in patients with underlying goiters, thyroid cancers and in immuno-compromised patients. The usual causative organisms are Staphylococci spp. and Streptococci spp. Rarer organisms include Klebsiella spp. and Salmonella spp. Due to its rarity (as there have been only 28 cases of Salmonella thyroid abscess being reported in the literature till 2020), only case reports are available to guide management. We report two cases of thyroid abscess due to Salmonella enteritidis in our institution that may herald the re-emergence of this uncommon infection of the thyroid gland and to raise awareness for all clinicians. Both patients presented with neck swelling, dysphagia and sepsis. Surgical intervention was warranted in both patients due to the severity of the disease and failed medical therapy. Recovery was uneventful following adequate surgical intervention and antibiotic therapy according to the culture and sensitivity report of the pathogen. This case report highlights that both patients were immunocompromised, and they contracted Salmonella thyroid abscess without any gastrointestinal involvement. Thus, a high index of suspicion for Salmonella thyroid abscess in immunocompromised patients can expedite the diagnosis and appropriate management can be commenced such as antibiotic therapy, percutaneous aspiration and surgical drainage in the event of failed medical therapy.

Randomized controlled trial comparing bilateral superficial cervical plexus block and local wound infiltration for pain control in thyroid surgery.

BACKGROUD/OBJECTIVE: Multiple approaches have been devised for pain control in patients undergoing thyroid surgery, with local wound infiltration (LWI) of analgesia and bilateral superficial cervical plexus block (BSCPB) among the popular choices cited. However, the results comparing these methods had either been contradictory or equivocal. This study was carried out to assess the efficacy of BSCPB in comparison to LWI in reducing post-operative pain, as well as any additional opioid requirement in the first 24 h after thyroid surgery. METHODS: A prospective, double-blinded randomized controlled trial comparing the post-operative pain score between BSCPB and LWI was conducted among patients undergoing thyroid surgery. Ropivacaine 0.50% was used in the study. Pain score was measured at 4, 12, 16 and 24 h after surgery using the visual analog scale (VAS). Subcutaneous injection of Tramadol was given whenever the pain score was ≥4 or requested by patients. RESULTS: A total of 70 patients were recruited, with 35 patients on each arm. There was no statistical difference in the post-operative pain score between the two groups at 4 h (p = 0.208), 12 h (p = 0.860), 16 h (p = 0.376) and 24 h (p = 0.375) after surgery. Time to the first rescue dose of Tramadol between the two arms was also insignificant (p = 0.949). One patient in the BSCPB arm developed transient left upper limb weakness, which resolved 12 h after surgery. CONCLUSION: LWI remains the simplest, safest and most economical method of pain management. While BSCPB is comparable, it does however, come with potential regional block related complications.

Papillary Thyroid Cancer: Genetic Alterations and Molecular Biomarker Investigations.

Papillary thyroid cancer (PTC) is the most prevalent form of malignancy among all cancers of the thyroid. It is also one of the few cancers with a rapidly increasing incidence. PTC is usually contained within the thyroid gland and generally biologically indolent. Prognosis of the cancer is excellent, with less than 2% mortality at 5 years. However, more than 25% of patients with PTC developed a recurrence during a long term follow-up. The present article provides an updated condensed overview of PTC, which focuses mainly on the molecular alterations involved and recent biomarker investigations.

A comparison of aesthetic outcome between tissue adhesive and subcuticular suture in thyroidectomy wound closure in a multiracial country: A randomized controlled trial.

OBJECTIVES: Monofilament sutures, both absorbable and non-absorbable, have been used for wound closure. Tissue adhesive has been used in closure of clean, low tension wounds. However, there have been very few published studies on the aesthetic outcomes in neck surgeries. The aim of this study is to compare the patients' and doctors' satisfaction scores in the aesthetic outcome between both methods of closure of thyroidectomy wounds using validated scoring systems. METHODS: A double-blinded randomised controlled trial comparing the aesthetic outcome between tissue adhesive and conventional suture was conducted among patients undergoing thyroid and parathyroid surgeries. Ninety-six patients were randomised into two treatment groups. Patients' wounds were scored by an independent observer using the SBSES score at 6 weeks postoperatively and observer component of the POSAS score at 3 months. RESULTS: Forty-nine patients were randomised to the tissue adhesive group while forty-seven patients received the conventional method. There was no statistical difference in the aesthetic outcome using the patient's scoring system between both arms, with a median score of 9 (p = 0.25, SD ± 6.5). The observer's satisfaction score using POSAS was also not statistically significant (median score of 14 (p = 0.77, SD ± 6.2)). No significance was found in the observer's median score using the SBSES scoring system either (score 3, p = 0.12, SD ± 1.3). However, there was significant reduction in the duration of closure using glue (4.42 mins vs 6.36 mins, p < 0.05). CONCLUSION: Tissue adhesive offers a comparable cosmetic result to the absorbable suture in thyroidectomy wound closure.

iTRAQ analysis of urinary proteins: Potential use of gelsolin and osteopontin to distinguish benign thyroid goiter from papillary thyroid carcinoma.

BACKGROUND: Benign thyroid goiter (BTG) and papillary thyroid carcinoma (PTC) are often interchangeably misdiagnosed. METHODS: Pooled urine samples of patients with BTG (n=10), patients with PTC (n=9) and healthy controls (n=10) were subjected to iTRAQ analysis and immunoblotting. RESULTS: The ITRAQ analysis of the urine samples detected 646 proteins, 18 of which showed significant altered levels (p<0.01; fold-change>1.5) between patients and controls. Whilst four urinary proteins were commonly altered in both BTG and PTC patients, 14 were unique to either BTG or PTC. Amongst these, four proteins were further chosen for validation using immunoblotting, and the enhanced levels of osteopontin in BTG patients and increased levels of a truncated gelsolin fragment in PTC patients, relative to controls, appeared to corroborate the findings of the iTRAQ analysis. CONCLUSION: The data of the present study is suggestive of the potential application of urinary osteopontin and gelsolin to discriminate patients with BTG from those with PTC non-invasively. However, this needs to be further validated in studies of individual urine samples.

Tissue and serum samples of patients with papillary thyroid cancer with and without benign background demonstrate different altered expression of proteins.

BACKGROUND: Papillary thyroid cancer (PTC) is mainly diagnosed using fine-needle aspiration biopsy. This most common form of well-differentiated thyroid cancer occurs with or without a background of benign thyroid goiter (BTG). METHODS: In the present study, a gel-based proteomics analysis was performed to analyse the expression of proteins in tissue and serum samples of PTC patients with (PTCb; n = 6) and without a history of BTG (PTCa; n = 8) relative to patients with BTG (n = 20). This was followed by confirmation of the levels of proteins which showed significant altered abundances of more than two-fold difference (p < 0.01) in the tissue and serum samples of the same subjects using ELISA. RESULTS: The data of our study showed that PTCa and PTCb distinguish themselves from BTG in the types of tissue and serum proteins of altered abundance. While higher levels of alpha-1 antitrypsin (A1AT) and heat shock 70 kDa protein were associated with PTCa, lower levels of A1AT, protein disulfide isomerase and ubiquitin-conjugating enzyme E2 N seemed apparent in the PTCb. In case of the serum proteins, higher abundances of A1AT and alpha 1-beta glycoprotein were detected in PTCa, while PTCb was associated with enhanced apolipoprotein A-IV and alpha 2-HS glycoprotein (AHSG). The different altered expression of tissue and serum A1AT as well as serum AHSG between PTCa and PTCb patients were also validated by ELISA. DISCUSSION: The distinctive altered abundances of the tissue and serum proteins form preliminary indications that PTCa and PTCb are two distinct cancers of the thyroid that are etiologically and mechanistically different although it is currently not possible to rule out that they may also be due other reasons such as the different stages of the malignant disease. These proteins stand to have a potential use as tissue or serum biomarkers to discriminate the three different thyroid neoplasms although this requires further validation in clinically representative populations.

Functional analyses of C.2268dup in thyroid peroxidase gene associated with goitrous congenital hypothyroidism.

The c.2268dup mutation in thyroid peroxidase (TPO) gene was reported to be a founder mutation in Taiwanese patients with dyshormonogenetic congenital hypothyroidism (CH). The functional impact of the mutation is not well documented. In this study, homozygous c.2268dup mutation was detected in two Malaysian-Chinese sisters with goitrous CH. Normal and alternatively spliced TPO mRNA transcripts were present in thyroid tissues of the two sisters. The abnormal transcript contained 34 nucleotides originating from intron 12. The c.2268dup is predicted to generate a premature termination codon (PTC) at position 757 (p.Glu757X). Instead of restoring the normal reading frame, the alternatively spliced transcript has led to another stop codon at position 740 (p.Asp739ValfsX740). The two PTCs are located at 116 and 201 nucleotides upstream of the exons 13/14 junction fulfilling the requirement for a nonsense-mediated mRNA decay (NMD). Quantitative RT-PCR revealed an abundance of unidentified transcripts believed to be associated with the NMD. TPO enzyme activity was not detected in both patients, even though a faint TPO band of about 80 kD was present. In conclusion, the c.2268dup mutation leads to the formation of normal and alternatively spliced TPO mRNA transcripts with a consequential loss of TPO enzymatic activity in Malaysian-Chinese patients with goitrous CH.

Thyroid rupture secondary to blunt neck trauma.

Rupture of the thyroid gland is uncommon in cases of blunt neck trauma. We report a case of thyroid rupture after a motor vehicle accident in a patient without a preexisting goiter. He presented with a painful anterior neck swelling associated with dysphagia and hoarseness of voice. Computed tomographic scans showed lacerations of the right thyroid lobe and isthmus with features suggestive of slow active bleeding. Neck exploration was subsequently performed, and a ruptured right thyroid lobe was found with ongoing venous hemorrhage. A right hemithyroidectomy was performed, and the patient recovered without complications.