Data Availability StatementAll relevant data are included within the paper. hsa-miR-200a-5p showed negative correlation to that of TPO (rs = – 0.734; **: 0.01) and CD56 (rs = – 0.570; **: 0.01), but KIAA0562 antibody positive correlation to that of Galectin-3 (rs = 0.601; **: 0.01), MC (rs = 0.508; **: 0.01), CK19 (rs = 0.712; **: P 0.01) and B-raf (rs = Imiquimod pontent inhibitor 0.378; **: P 0.01). PTC and papillary benign thyroid papillary hyperplasia are hard to distinguish in morphology, so requiring immunohistochemistry to further differentiate the diagnosis, however, for the existing clinical common diagnostic marker for immunohistochemistry, the sensitivity and accuracy are low, it is easy to miss diagnosis. Therefore, there is an urgent need for a rapid and sensitive molecular marker. So miR-200a-5p can be used to assist in the diagnosis of PTC at the molecular level, and as a biomarker, can be effectively used to distinguish Imiquimod pontent inhibitor between PTC and benign thyroid tumor with papillary hyperplasia. Introduction Thyroid carcinoma is the most common endocrine malignancy with a significantly increase of the incidence in recent years, especially in young men [1C7]. According to the histogenesis and morphology, thyroid carcinomas can be classified into papillary thyroid carcinoma (PTC) , follicular carcinoma , medullary carcinoma  and undifferentiated carcinoma . PTC is the most common thyroid malignant tumor, generally with an indolent clinical course, accounting for about 60% to 70% of total thyroid cancers, [12C14]. The overall 5-year relative survival rate has Imiquimod pontent inhibitor been reported as high as 97.5%, and only a small percentage of papillary carcinomas show aggressive clinical behavior [12C13, 15C18]. Common PTC is usually characterized by papillary structures with characteristic nuclear morphology, such as glassy nuclei, nuclear grooves, and intranuclear inclusions. But it is usually difficult to distinguish from thyroid benign lesions, such as nodular goiter, Hashimoto’s thyroiditis, and thyroid adenoma with papillary growth. At present, there are some markers for the differential diagnosis of PTC and benign thyroid tumor with papillary hyperplasia, such as CK19/Galectin-3/HBME1, but they are limited in clinical use because of their relative lower sensitivity and specificity. So it remains hard in the differential diagnosis. With the development of molecular biology and the emergence of various biomarkers, many experts try to find new molecular biomarkers for early diagnosis and evaluation of prognosis of thyroid cancers. MicroRNA (miRNA) are small non-corning RNA, approximately 18C22 nucleotide, and can post-transcriptionally regulate gene expression by binding to 3-untranslated region of mRNAs, regulating target mRNAs transcript degradation or translational repression, and then extensively regulating biological functions, including tumorigenesis and development [20C23]. In addition, many researchers have reported the integrated genomic characterization, microRNA, gene expression and transcription factors signature of papillary thyroid carcinoma, and confirmed the correlation between PTC and microRNA [24C26]. Hsa-miR-200 family is usually a hot topic in recent years, which includes 5 users (miR-200a, miR-200b, miR-200c, miR-141 and miR-429) located on two different genomic clusters: one cluster including miR-200a, miR-200b and miR-429 on chromosome 1, and another cluster including miR-200c and miR-141 on chromosome 12[27C28]. Hsa-miR-200a, as one of its important members, has begun to attract much more attention since studies showed that hsa-miR-200a could inhibit the occurrence of renal cell carcinoma by inducing cell apoptosis through directly targeting SIRT1 [29C30]. It can regulate the endometrial malignancy cell growth in vitro by targeting phosphatase and tensin homolog (PTEN) [31C32]. In addition, in tumorigenesis of colorectal malignancy, hsa-miR-200a can target PTEN to promote colorectal malignancy development. Chen 0.05 and 0.01 were considered as significant differences and highly significant differences, respectively. Results The hsa-miR-200a-5p expressive level was significantly increased in papillary thyroid carcinoma patients As in Fig 1 and Table 1, when compared to control, the hsa-miR-200a-5p expressive level was significantly increased in PTC patients, consistent with that of Galectin-3, Imiquimod pontent inhibitor MC, CK19 and B-raf. However, the expressive level of TPO and CD56 was significantly decreased. Open in a separate windows Fig 1 The assay of hsa-miR-200a-5p expressive level by in situ hybridization, and TPO, CD56, Galectin-3, MC, CK19 and B-raf expressive.