Measurement of Calcitonin and Calcitonin Gene-Related Peptide mRNA Refines the Management of Patients with Medullary Thyroid Cancer and May Replace Calcitonin-Stimulation Tests
THYROID
Authors: Camacho, Cleber P.; Lindsey, Susan C.; Melo, Maria Clara C.; Yang, Ji H.; Germano-Neto, Fausto; Valente, Flavia de O. F.; Lima, Thiago R. N.; Biscolla, Rosa Paula M.; Vieira, Jose G. H.; Cerutti, Janete M.; Dias-da-Silva, Magnus R.; Maciel, Rui M. B.
Abstract
Background: Serum calcitonin (sCT) is the main tumor marker for medullary thyroid cancer (MTC), but it has certain limitations. Various sCT assays may have important intra-assay or interassay variation and may yield different and sometimes conflicting results. A pentagastrin-or calcium-stimulation calcitonin (CT) test may be desirable in some situations. Alternatively, or in the absence of the stimulation test, mRNA detection offers the advantages of being more comfortable and less invasive; it only requires blood collection and has no side effects. The objective of this study was to investigate the applicability of measuring calcitonin-related polypeptide alpha (CALCA) gene transcripts (CT-CALCA and calcitonin gene-related peptide [CGRP]-CALCA) in patients with MTC and in relatives diagnosed with a RET mutation and to test mRNA as an alternative diagnostic tool for the calcitonin-stimulation test. Methods: Twenty-three healthy controls and 26 individuals evaluated for MTC were selected, including patients with sporadic or hereditary MTC and RET mutation-carrying relatives. For molecular analysis, RNA was extracted from peripheral blood, followed by cDNA synthesis using 3.5 mu g of total RNA. Quantitative real-time polymerase chain reaction (RT-qPCR) was performed with SYBR Green and 200nM of each primer for the two specific mRNA targets (CT-CALCA or CGRP-CALCA) and normalized with the ribosomal protein S8 as the reference gene. Results: We detected CALCA transcripts in the blood samples and observed a positive correlation between them (r = 0.946, p < 0.0001). Both mRNAs also correlated with sCT (CT-CALCA, r = 0.713, p < 0.0001; CGRP-CALCA, r = 0.714, p < 0.0001). The relative expression of CT-CALCA and CGRP-CALCA presented higher clinical sensitivity (86.67 and 100, respectively), specificity (97.06 and 97.06), positive predictive value (92.86 and 93.75), and negative predictive value (94.29 and 100), than did sCT (73.33, 82.35, 64.71, and 87.50, respectively). In addition, the CALCA transcript measurement mirrored the response to the pentagastrin test. Conclusion: We demonstrate that the measurement of CALCA gene transcripts in the bloodstream is feasible and may refine the management of patients with MTC and RET mutation-carrying relatives. We propose considering the application of this diagnostic tool as an alternative to the calcitonin-stimulation test.
Alterations in Deoxyribonucleic Acid (DNA) Methylation Patterns of Calca, Timp3, Mmp2, and Igf2r Are Associated With Chronic Cystitis in a Cyclophosphamide-induced Mouse Model
UROLOGY
Authors: Choi, In-Seon; Yu, Kevin; Kim, Jayoung; De Guzman, Erika; Weisenberger, Daniel J.; Oghamian, Shirley; Kim, Hee Ju; Lee, Kyung Hwa; Carroll, Cindy; Trinh, Binh N.; Kim, Myungjin; Houshdaran, Sahar; Laird, Peter W.; Jones, Peter A.; Warburton, David; Liang, Gangning; Koh, Chester J.
Abstract
OBJECTIVE To determine whether epigenetic changes occur during cyclophosphamide-induced chronic bladder inflammation in mice. MATERIALS AND METHODS Epigenetic changes play a role in the regulation of inflammatory genes in noncancer diseases such as asthma and chronic obstructive pulmonary disease. However, epigenetic (deoxyribonucleic acid [DNA] methylation) changes during chronic bladder inflammation have not been previously described. Chronic cystitis was induced in 3 groups of adult CD-1 male mice using multiple weight-based intraperitoneal cyclophosphamide injections during a 3-month period. Histopathologic and MethyLight assays were performed on specimens with chronic bladder inflammation at multiple points to monitor cystitis progression and DNA methylation changes compared with the control specimens. RESULTS Histopathologic analysis showed the most extensive edema and urothelial sloughing at the 1-month point. MethyLight analyses revealed statistically significant changes in DNA methylation associated with the Calca, Timp3, Mmp2, and Igf2r genes in the chronic bladder injury model. The changes in DNA methylation associated with chronic cystitis were DNA hypomethylation of the Calca gene in the control tissue and DNA hypermethylation for the Calca, Timp3, Mmp2, and Igf2r genes compared with that in the control tissue. CONCLUSION DNA methylation changes were noted in the Calca, Timp3, Mmp2, and Igf2r genes during chronic cystitis in a murine model. Epigenetic changes appear to play a role in the regulation of inflammatory bladder genes during chronic cystitis; however, additional studies are needed to elucidate the pathways associated with these genes. UROLOGY 82: 253.e9 253.e15, 2013. (C) 2013 Elsevier Inc.