miRNA profiling, detection of BRAF V600E mutation and RET-PTC1 translocation in patients from Novosibirsk oblast (Russia) with different types of thyroid tumors

Abstract

BackgroundThe postoperative typing of thyroid lesions, which is instrumental in adequate patient treatment, is currently based on histologic examination. However, it depends on pathologist’s qualification and can be difficult in some cases. Numerous studies have shown that molecular markers such as microRNAs and somatic mutations may be useful to assist in these cases, but no consensus exists on the set of markers that is optimal for that purpose. The aim of the study was to discriminate between different thyroid neoplasms by RT-PCR, using a limited set of microRNAs selected from literature.MethodsBy RT-PCR we evaluated the relative levels of 15 microRNAs (miR-221, −222, −146b, −181b, −21, −187, −199b, −144, −192, −200a, −200b, −205, −141, −31, −375) and the presence of BRAF(V600E) mutation and RET-PTC1 translocation in surgically resected lesions from 208 patients from Novosibirsk oblast (Russia) with different types of thyroid neoplasms. Expression of each microRNA was normalized to adjacent non-tumor tissue. Three pieces of lesion tissue from each patient (39 goiters, 41 follicular adenomas, 16 follicular thyroid cancers, 108 papillary thyroid cancers, 4 medullary thyroid cancers) were analyzed independently to take into account method variation.ResultsThe diagnostic classifier based on profiling of 13 microRNAs was proposed, with total estimated accuracy varying from 82.7 to 99 % for different nodule types. Relative expression of six microRNAs (miR-146b, −21, −221, −222, 375, −199b) appeared significantly different in BRAF(V600E)-positive samples (all classified as papillary thyroid carcinomas) compared to BRAF(V600E)-negative papillary carcinoma samples.ConclusionsThe results confirm practical feasibility of using molecular markers for typing of thyroid neoplasms and clarification of controversial cases.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-016-2240-2) contains supplementary material, which is available to authorized users.

Analysis of Relative Expression of the Hmga2 Gene and Oncogenic Microrna-221 in Cytological Slides Obtained by a Fine-Needle Aspiration Biopsy of the Thyroid Nodules

“…Выделение нуклеиновых кислот из цитологических препаратов и анализ содержания микроРНК выполняли, как описано ранее [23]. Нормировку уровня миРНК-221 проводили на содержание референсной миРНК-197 [24] , где Ct -пороговый цикл реакции для соответствующей микроРНК.…”

miRNA-148a inhibits cell growth of papillary thyroid cancer through STAT3 and PI3K/AKT signaling pathways

“…The association of miRNA with tumor has been explained gradually accompanied by increase in research on microRNA (miRNA) (3). It is indicated in research that miRNA is closely related to tumor genesis, metastasis, as well as sensitivity of tumor cells to antitumor drugs (4).…”

“…miRNAs are a class of non-coding single-stranded small RNA molecules with the length of 19-23 nucleotides, which locate in the non-coding region of the genome (3). miRNAs, which are highly conserved in evolution, can regulate gene expression at translation level.…”

Selection and validation of miRNAs as normalizers for profiling expression of microRNAs isolated from thyroid fine needle aspiration smears

“…Isolation of the total nucleic acids and detection of miRNAs and RNU6 by RT-qPCR was performed as previously described (18). …”

“…Evaluation of human DNA content was performed by qPCR as previously described (18), using oligos for the conserved region of chromosome 15. The sequences of all new oligos missing in our previous study (18) are listed in Table I.…”