Development of Metabolic Synthetic Lethality and Its Implications for Thyroid Cancer

Cancer therapies targeting genetic alterations are a topic of great interest in the field of thyroid cancer, which frequently harbors mutations in the RAS, RAF, and RET genes. Unfortunately, U.S. Food and Drug Administration-approved BRAF inhibitors have relatively low therapeutic efficacy against BRAF-mutant thyroid cancer; in addition, the cancer often acquires drug resistance, which prevents effective treatment. Recent advances in genomics and transcriptomics are leading to a more complete picture of the range of mutations, both driver and messenger, present in thyroid cancer. Furthermore, our understanding of cancer suggests that oncogenic mutations drive tumorigenesis and induce rewiring of cancer cell metabolism, which promotes survival of mutated cells. Synthetic lethality (SL) is a method of neutralizing mutated genes that were previously considered untargetable by traditional genotype-targeted treatments. Because these metabolic events are specific to cancer cells, we have the opportunity to develop new therapies that target tumor cells specifically without affecting healthy tissue. Here, we describe developments in metabolism-based cancer therapy, focusing on the concept of metabolic SL in thyroid cancer. Finally, we discuss the essential implications of metabolic reprogramming and its role in the future direction of SL for thyroid cancer.

Metabolite Changes during the Transition from Hyperthyroidism to Euthyroidism in Patients with Graves’ Disease

Background@#An excess of thyroid hormones in Graves’ disease (GD) has profound effects on systemic energy metabolism that are currently partially understood. In this study, we aimed to provide a comprehensive understanding of the metabolite changes that occur when patients with GD transition from hyperthyroidism to euthyroidism with methimazole treatment. @*Methods@#Eighteen patients (mean age, 38.6±14.7 years; 66.7% female) with newly diagnosed or relapsed GD attending the endocrinology outpatient clinics in a single institution were recruited between January 2019 and July 2020. All subjects were treated with methimazole to achieve euthyroidism. We explored metabolomics by performing liquid chromatography-mass spectrometry analysis of plasma samples of these patients and then performed multivariate statistical analysis of the metabolomics data. @*Results@#Two hundred metabolites were measured before and after 12 weeks of methimazole treatment in patients with GD. The levels of 61 metabolites, including palmitic acid (C16:0) and oleic acid (C18:1), were elevated in methimazole-naïve patients with GD, and these levels were decreased by methimazole treatment. The levels of another 15 metabolites, including glycine and creatinine, were increased after recovery of euthyroidism upon methimazole treatment in patients with GD. Pathway analysis of metabolomics data showed that hyperthyroidism was closely related to aminoacyl-transfer ribonucleic acid biosynthesis and branched-chain amino acid biosynthesis pathways. @*Conclusion@#In this study, significant variations of plasma metabolomic patterns that occur during the transition from hyperthyroidism to euthyroidism were detected in patients with GD via untargeted metabolomics analysis.

Multiple Fractures in Patient with Graves' Disease Accompanied by Isolated Hypogonadotropic Hypogonadism

Isolated hypogonadotropic hypogonadism (IHH) is known to decrease bone mineral density due to deficiency of sex steroid hormone. Graves' disease is also an important cause of secondary osteoporosis. However, IHH does not preclude the development of primary hyperthyroidism caused by Graves' disease, leading to more severe osteoporosis rapidly. Here, we describe the first case of 35-year-old Asian female patient with IHH accompanied by Graves' disease and osteoporosis-induced multiple fractures. Endocrine laboratory findings revealed preserved anterior pituitary functions except for secretion of gonadotropins and showed primary hyperthyroidism with positive autoantibodies. Sella magnetic resonance imaging showed slightly small sized pituitary gland without mass lesion. Dual energy X-ray absorptiometry revealed severe osteoporosis in lumbar spine and femur neck of the patient. Plain film radiography of the pelvis and shoulder revealed a displaced and nondisplaced fracture, respectively. After surgical fixation with screws for the femoral fracture, the patient was treated with antithyroid medication, calcium, and vitamin D until now and has been recovering fairly well. We report a patient of IHH with Graves' disease and multiple fractures that is a first case in Korea.

A Case of Low Bone Mineral Density with Vitamin D Deficiency Due to Prolonged Lactation and Severe Malnutrition

Malnutrition associated vitamin D deficiency contributes to the calcium loss from bone and results in osteoporosis and osteomalacia at final stage. Osteomalacia is characterized with softening of bone secondary to defective bone mineralization. Here, we report a case of possible osteomalacia caused by prolonged lactation and severe malnutrition in 35-year-old female. She was a housewife and her body mass index was 11.8 kg/m2. She was diagnosed with severe osteoporosis in regular health check-up 2 years ago, but did not take any medication. Nine months ago, she had been treated with anti-tuberculosis medications for 6 month due to active pulmonary tuberculosis. After complete remission of pulmonary tuberculosis, she had lost her appetite severely. Furthermore, she felt gait difficulty and suffered from generalized bone pain. On serologic examination, hypocalcemia, hypophosphatemia, high alkaline phosphatase, low vitamin D3 and high parathyroid hormone level were seen. In the bone mineral density, Z-score from her lumbar spine was -6.5. She was treated with oral calcium and vitamin D3 intramuscularly. After 1 year treatment, she felt significant improvement in bone pain and could walk alone. Also her serum calcium, phosphate and vitamin D3 level are all normalized.

Validation of Waist-to-Height Ratio for Predicting Metabolic Syndrome in Patients with Prediabetes

BACKGROUND: Metabolic syndrome is associated with type 2 diabetes and cardiovascular disease in patients with prediabetes. The aim of this study was to investigate and compare WHtR (Waist-to-Height Ratio) as a predictor of metabolic syndrome with other anthropometric indices as in Body Mass Index (BMI), Waist Circumference (WC) and Waist to Hip Ratio (WHR) in prediabetes. METHODS: A total of 816 subjects with prediabetes were recruited from a community based Cohort Study. Receiver operating characteristic (ROC) curve was performed to find the optimal cutoff value of WHtR. Area under the curve (AUC) was calculated for each anthropometric index and correlation coefficient between WHtR and various dermographic and clinical factors was calculated. RESULTS: WHtR had a significant correlation with metabolic parameters except for fasting glucose and increased with increasing number of risk factors for metabolic syndrome. AUC of WHtR was significantly higher than that of other anthropometric indices. The optimal cutoff value of WHtR was 0.53 for metabolic syndrome in prediabetes. CONCLUSION: WHtR may be the simple and effective anthropometric index for predicting metabolic syndrome in prediabetic patients.