Gene Master Regulators of Papillary and Anaplastic Thyroid Cancers

We hypothesize that distinct cell phenotypes are governed by different sets of gene master regulators (GMRs) whose strongly protected (by the homeostatic mechanisms) abundance modulates most cell processes by coordinating the expression of numerous genes from the corresponding functional pathways. Gene Commanding Height (GCH), a composite measure of gene expression control and coordination, is introduced to establish the gene hierarchy in each phenotype. If the hypothesis is true, than one can selectively destroy cancer nodules from a heterogeneous tissue by altering the expression of genes whose GCHs are high in cancer but low in normal cell phenotype. Here, we test the hypothesis and show its utility for the thyroid cancer (TC) gene therapy. First, we prove that malignant and cancer free surrounding areas of a surgically removed papillary TC (PTC) tumor are governed by different GMRs. Second, we show that stable transfection of a gene induces larger transcriptomic alterations in the cells where it has higher GCH than in other cells. For this, we profiled the transcriptomes of the papillary BCPAP and anaplastic 8505C TC cell lines before and after stable transfection with NEMP1, DDX19B, PANK2 or UBALD1. The four genes were selected to have similar expression levels but significantly different GCH scores in the two cell lines before transfection. Indeed, each of the four genes triggered larger alterations in the cells where they had larger GCH. Our results prove the feasibility of a personalized gene therapy approach that selectively targets the cancer cells from a tissue

Hyperactive ERK and Persistent mTOR Signaling Characterize Vemurafenib Resistance in Papillary Thyroid Cancer Cells

Clinical studies evaluating targeted BRAFV600E inhibitors in advanced thyroid cancer patients are currently underway. Vemurafenib (BRAFV600E inhibitor) monotherapy has shown promising results thus far, although development of resistance is a clinical challenge. The objective of this study was to characterize development of resistance to BRAFV600E inhibition and to identify targets for effective combination therapy. We created a line of BCPAP papillary thyroid cancer cells resistant to vemurafenib by treating with increasing concentrations of the drug. The resistant BCPAP line was characterized and compared to its sensitive counterpart with respect to signaling molecules thought to be directly related to resistance. Expression and phosphorylation of several critical proteins were analyzed by Western blotting and dimerization was evaluated by immunoprecipitation. Resistance to vemurafenib in BCPAP appeared to be mediated by constitutive overexpression of phospho-ERK and by resistance to inhibition of both phospho-mTOR and phospho-S6 ribosomal protein after vemurafenib treatment. Expression of potential alternative signaling molecule, CRAF, was not increased in the resistant line, although formation of CRAF dimers appeared increased. Expression of membrane receptors HER2 and HER3 was greatly amplified in the resistant cancer cells. Papillary thyroid cancer cells were capable of overcoming targeted BRAFV600E inhibition by rewiring of cell signal pathways in response to prolonged vemurafenib therapy. Our study suggests that in vitro culture of cancer cells may be useful in assessing molecular resistance pathways. Potential therapies in advanced thyroid cancer patients may combine vemurafenib with inhibitors of CRAF, HER2/HER3, ERK, and/or mTOR to delay or abort development of resistance

Androgen Activity Is Associated With PD-L1 Downregulation in Thyroid Cancer

Thyroid cancer is the most prevalent endocrine malignancy in the United States with greater than 53,000 new cases in 2020. There is a significant gender disparity in disease incidence as well, with women developing thyroid cancer three times more often than men; however, the underlying cause of this disparity is poorly understood. Using RNA-sequencing, we profiled the immune landscape of papillary thyroid cancer (PTC) and identified a significant inverse correlation between androgen receptor (AR) levels and the immune checkpoint molecule PD-L1. The expression of PD-L1 was then measured in an androgen responsive-thyroid cancer cell line. Dihydrotestosterone (DHT) treatment resulted in significant reduction in surface PD-L1 expression in a time and dose-dependent manner. To determine if androgen-mediated PD-L1 downregulation was AR-dependent, we treated cells with flutamide, a selective AR antagonist, and prior to DHT treatment to pharmacologically inhibit AR-induced signaling. This resulted in a \u3e 90% restoration of cell surface PD-L1 expression, suggesting a potential role for AR activity in PD-L1 regulation. Investigation into the AR binding sites showed AR activation impacts NF-kB signaling by increasing IkBalpha and by possibly preventing NF-kB translocation into the nucleus, reducing PD-L1 promoter activation. This study provides evidence of sex-hormone mediated regulation of immune checkpoint molecules in vitro with potential ramification for immunotherapies

Cystic hygroma and potential airway obstruction in a newborn: a case report and review of the literature

BACKGROUND: Cervical cystic hygroma is a benign congenital malformation of the lymphatic system. Incidence of cystic hygroma is 1/6000 live births. We present a case of right neck mass with potential respiratory compromise in a newborn. CASE PRESENTATION: The patient was a full term baby girl with an incidental finding of right neck mass which was described on ultrasound and magnetic resonance imaging as a cystic lesion in the nasopharynx and right neck which inferiorly followed the course of the right carotid artery, consistent with cystic hygroma. She started with respiratory compromise, and a follow-up magnetic resonance imaging showed increased size of the cystic hygroma. Dexamethasone was started to reduce fluid build up in the mass. When the cystic hygroma was found to be inseparable from the right half of the thyroid gland, the otolaryngologist performed hemithyroidectomy. CONCLUSION: The patient had neuropraxia involving the marginal mandibular branch of the facial nerve, which was expected to correct with time. Large cervical cystic hygromas may surround or displace neurovascular structures making their identification quite challenging intraoperatively. A team of experienced surgeons will help to ensure a successful surgical outcome

MRI Findings of Causalgia of the Lower Extremity Following Transsphenoidal Resection of Pituitary Tumor

Background. Causalgia is continuing pain, allodynia, or hyperalgesia after nerve injury with edema, changes in skin blood flow, or abnormal sudomotor activity. Here we report a case of lower extremity causalgia following elective transsphenoidal resection of a pituitary tumor in a young man. Clinical Presentation. A 33-year-old man with acromegaly underwent elective sublabial transsphenoidal resection of his pituitary tumor. During the three-hour surgery, the lower limbs were kept in a supine, neutral position with a pillow under the knees. The right thigh was slightly internally rotated with a tape to expose fascia lata, which was harvested to repair the sella. Postoperatively, he developed causalgia in a distal sciatic and common peroneal nerve distribution. Pain was refractory to several interventions. Finally, phenoxybenzamine improved his pain significantly. Conclusions. Malpositioning in the operating room resulted in causalgia in this young man. Phenoxybenzamine improved, and ultimately resolved, his symptoms. Improvement in his pain symptoms correlated with resolution of imaging changes in the distal sciatic and peroneal nerves on the side of injury

Endoscopic resection of nasal schwanomma as a diagnostic and therapeutic adjunct in the treatment of a rare disorder: A case report with literature review

Isolated nasal schwannomas are rare lesions that can be difficult to diagnose due to nonspecific characteristics. We report a unique case of a patient with a polypoid mass abutting the lacrimal sac found to be a nasal schwanomma. A 66-year-old male with a history of previously resected nasal polyposis returned to the office complaining of symptoms suggestive of rhinosinusitis. Endoscopy was significant for a polypoid mass superior to the inferior turbinate. CT imaging revealed a 2 × 1.8 × 1.3 cm lesion in the right nasal cavity with bony erosion overlying the lacrimal sac. Following endoscopic resection, pathologic analysis revealed a nasal schwanomma based on S100 and Ki-67 staining patterns. The patient has been doing well for over 6 months without recurrence. Although rare, nasal schwanomma should be kept in the differential of any nasal mass, and endoscopic resection can serve as a useful tool in the management of this disorder

Coding and Noncoding RNA Determinants of Invasion and Migration in Papillary Thyroid Cancer

Papillary thyroid cancer (PTC) is now the 8th most common cancer in women in the United States and has been increasing in incidence over the last few decades. While it is often curable, aggressive forms of PTC that are not adequately treated by current therapeutic modalities invade into surrounding tissue, with a poor prognosis. Thus, the identification of genes involved in PTC migration and invasion is an unmet need. Differentially expressed (PTC vs. matched, normal) coding and noncoding genes from our own biobank were ranked, comparing invasive vs noninvasive, and lymph node positive vs lymph node negative samples. This analysis was supplemented with the interrogation s of The Cancer Genome Atlas (TCGA) PTC gene expression database for survival-associated genes (Kaplan Meier survival curves) utilizing the Xena Browser. This meta-analysis identified genes with a significant impact on survival, that correlated with lymph node metastasis and tumor invasion. SPOCK3, a Ca+2-binding proteoglycan protein with metalloendopeptidase activity, with a role in both extracellular matrix (ECM) degradation and ERK signaling, correlated with both invasiveness and lymph node spread. SLC30A3 (Solute Carrier Family 30 Member 3), involved in the accumulation of zinc in synaptic vesicles and the transport of sugars, bile salts, organic acids, metal ions and amine compounds, also correlated with both invasiveness and lymph node spread. COL26A1, was found to be correlated to tumor invasion and codes for collagen type XXVI α1 chain with known roles in degradation of the ECM and collagen chain trimerization. Long noncoding RNAs (lncRNAs) have vast implications in different cancer types with roles in gene expression via modulation of coding and noncoding RNAs, and are cell, tissue and stage-specific. lncRNAs were identified that correlated with differentiation, invasion and lymph node spread. CRISPR guides were designed and introduced into thyroid cancer cell lines and decreased the invasion and migration capacity of the thyroid cancer cells. This implies their potential use as prognostic markers and actionable therapeutic targets for small molecule inhibitors

Cystic hygroma and potential airway obstruction in a newborn: a case report and review of the literature.

BACKGROUND: Cervical cystic hygroma is a benign congenital malformation of the lymphatic system. Incidence of cystic hygroma is 1/6000 live births. We present a case of right neck mass with potential respiratory compromise in a newborn. CASE PRESENTATION: The patient was a full term baby girl with an incidental finding of right neck mass which was described on ultrasound and magnetic resonance imaging as a cystic lesion in the nasopharynx and right neck which inferiorly followed the course of the right carotid artery, consistent with cystic hygroma. She started with respiratory compromise, and a follow-up magnetic resonance imaging showed increased size of the cystic hygroma. Dexamethasone was started to reduce fluid build up in the mass. When the cystic hygroma was found to be inseparable from the right half of the thyroid gland, the otolaryngologist performed hemithyroidectomy. CONCLUSION: The patient had neuropraxia involving the marginal mandibular branch of the facial nerve, which was expected to correct with time. Large cervical cystic hygromas may surround or displace neurovascular structures making their identification quite challenging intraoperatively. A team of experienced surgeons will help to ensure a successful surgical outcome

Noncoding RNAs in Papillary Thyroid Cancer: Interaction with Cancer-Associated Fibroblasts (CAFs) in the Tumor Microenvironment (TME) and Regulators of Differentiation and Lymph Node Metastasis

A large majority of all thyroid cancers are papillary thyroid carcinomas (PTC), named for the specific papillary architecture observed histologically. Despite the high rate of success with modern diagnostic and therapeutic algorithms, there are significant areas where the management of PTC can be improved. Aggressive PTC subtypes that are refractory to radioactive iodine (RAI) therapy carry a more severe prognosis and account for most of PTC-related deaths. As lymph node metastasis is present in roughly 40% of all adult PTC cases, higher specificity in these tests is a clinical need, especially since lymph node metastases are associated with reduced survival and higher recurrence rates. Additionally, this cancer can progress to more dedifferentiated and aggressive variants, such as poorly differentiated papillary thyroid cancer (PDPTC) and anaplastic thyroid cancer (ATC). Therefore, development of more sensitive and specific detection methods that allow unnecessary surgeries to be avoided is of the utmost importance. The body of large-scale, unbiased gene expression analysis in PTC has focused on the coding transcriptome, specifically mRNAs and microRNAs. However, there have been implications for the potential use of long noncoding RNAs (lncRNAs) in PTC diagnosis, prognosis, and treatment via the utilization of genome-wide studies of patient samples. lncRNAs have diverse regulatory potential in gene expression, alternative splicing, posttranscriptional mRNA modification, and epigenomic alterations. Many lncRNAs have tissue-specific expression and are demonstrated to play key roles in cancer progression and prognosis. However, lncRNAs are not being exploited as biomarkers or therapeutic targets currently, despite their elucidated effects on oncogenesis. These potent biomarkers would be revolutionary in detection at early stages, as this significantly increases the chances of survival. Their aberrant expression in cancer and correlation with steps in tumorigenesis as well as their role in differentiation would allow for a promising role as a prognostic and diagnostic biomarker in thyroid cancer. This would help prevent the more aggressive ATC that derives from dedifferentiation of the less aggressive PTC and FTC. The targeting of the specific lncRNAs could also pose a valuable treatment option via preventing or reversing this dedifferentiation process and making this usually refractory form of thyroid cancer more responsive to standard treatment options