The relation of omentin gene expression and glucose homeostasis of visceral and subcutaneous adipose tissues in non-diabetic adults.

BACKGROUND: Adipose tissue (AT) is a passive reservoir for energy storage and an active endocrine organ responsible for synthesizing bioactive molecules called adipokines. Omentin is known as an anti-inflammatory adipokine that can modulate insulin sensitivity. The present study aimed to investigate the relationship between omentin mRNA expression and glucose homeostasis of visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) in non-diabetic adults. METHODS: VAT and SAT adipose tissues were collected from 137 adults aged ≥ 18 years hospitalized for abdominal surgery. Before surgery, preoperative blood samples were taken from the participants to measure fasting plasma glucose, insulin, and triglyceride. BMI, HOMA-IR, HOMA-B, and QUICKI were calculated. Insulin levels were measured with Mercodia kits using enzyme-linked immunosorbent assay (ELISA). In order to obtain omentin mRNA expression, real-time PCR was performed. RESULTS: Overall, 91 (66.4%) subjects were healthy [without insulin resistance (IR)], and 46 (33.6%) participants were with IR. In healthy and IR subjects, omentin gene expression was 1.04 and 2.32, respectively in VAT, and 3.06 and 1.30, respectively, in SAT (P > 0.05). After controlling for age and BMI, linear regression analysis indicated a significant positive association of SAT omentin expression with insulin concentration (ß = 0.048; 95% CI 0.009, 0.088, P = 0.017) and HOMA-IR (ß = 0.173; 95% CI 0.023, 0.323, P = 0.014). Moreover, a negative association of SAT omentin expression with HOMA-B (ß = - 0.001; 95% CI 0.002, - 0.001, P < 0.001) was observed. CONCLUSION: This study's finding confirms a direct association between IR with omentin mRNA levels in SAT. Besides, the indicator of insulin sensitivity had an inverse association with omentin gene expression in SAT. This aspect of research suggests that omentin secretion from SAT has a strong link with insulin regulation.

Utilizing the circulating tumor markers in diagnosis and management of medullary thyroid cancer.

Medullary thyroid cancer (MTC) is the third frequent subtype of thyroid cancer-driving from thyroid C-cells. The first-line strategy to treat MTC is surgery, but tumor recurrence and patients' mortality rate have still been demonstrated in approximately 4-10% of MTC cases. Therefore, to treat and prevent the progressive form of the disease, the early diagnosis of MTC is assumed to play a critical role. In this regard, recently, circulating biomarkers have drawn researchers' attention for their nonaggressive manners in the sample collection. In this systematic review, we aimed to focus on circulating biomarkers and their applications in MTC diagnosis, prognosis and follow-up, and we discussed their clinical application and how they can affect clinical decision making in the future. A literature search (from 2000 to 2021) was accomplished on MTC circulating biomarkers in different databases, and only English articles were evaluated. We found that calcitonin (CT) and carcinoembryonic antigen (CEA) are the most important circulating biomarkers in the MTC diagnosis. Other circulating biomarkers included pro-calcitonin (Pro-CT), pro-Gastrin releasing peptide (Pro-GRP), carbohydrate antigen 19-9 (CA 19-9) and chromogranin A (CgA). Some novel circulating biomarkers comprised vaspin and retinol-binding protein-4 (RBP4), myostatin, tumor cells (CTCs), RET M918T mutated cfDNA, circulating tumor DNA (ctDNA), miR-375 and Alu83 and Alu244 cfDNAs. Several circulating biomarkers have been identified to optimize the accuracy of diagnosis and offer new prognostic criteria, which should be verified before any clinical application. Although different circulating biomarkers contributed to MTC have been discovered, a few of them could be used in clinical diagnosis. In many cases, the application of each marker may not be useful lonely; therefore, a combination of two or more biomarkers could open a new avenue in the diagnosis, prognosis and prediction of MTC.