Papillary thyroid carcinoma (PTC) is the most common endocrine malignancy in the worlds. Long non-coding RNA X-inactive specific transcript (XIST) was found to upregulate in PTC tissues and cell lines. However, the molecular mechanism underlying PTC metastasis and whether XIST plays regulatory role in PTC are still largely unknown. qRT-PCR was performed to detect the expression of lncRNA XIST and mRNAs. Western blotting was carried out to detect CLDN1, MMP2, and MMP9. Transwell assay was used to detect migration and invasion. Starbase bioinformatics prediction and luciferase assay were used to validate the relationship of miR-101-3p and XIST or CLDN1. LncRNA XIST was upregulated in PTC tissues and cells. XIST knockdown suppressed migration and invasion of PTC cells. XIST could directly bind with miR-101-3p. Overexpression of miR-101-3p suppressed migration and invasion of PTC cells. CLDN1 was the target of miR-101-3p, and overexpression of CLDN1 can reverse the inhibition of cell migration and invasion by miR-101-3p, What’s more, miR-101-3p inhibition and CLDN1 overexpression can reverse the affection of sh-XIST on migration and invasion of PTC cells inhibition. XIST promotes migration and invasion of papillary thyroid cancer cell via directly regulating miR-101-3p/CLDN1 axis, which is a novel mechanistic of XIST in the regulation of PTC.

甲状腺乳头状癌（PTC）是世界上最常见的内分泌恶性肿瘤。发现长的非编码RNA X失活的特异性转录本（XIST）在PTC组织和细胞系中上调。然而，PTC转移的分子机制以及XIST是否在PTC中起调节作用仍是未知之数。进行qRT-PCR以检测lncRNA XIST和mRNA的表达。进行蛋白质印迹以检测CLDN1，MMP2和MMP9。用Transwell测定法检测迁移和侵袭。使用Starbase生物信息学预测和荧光素酶测定法来验证miR-101-3p与XIST或CLDN1的关系。LncRNA XIST在PTC组织和细胞中上调。XIST组合式抑制了PTC细胞的迁移和侵袭。XIST可以直接与miR-101-3p结合。miR-101-3p的过表达抑制了PTC细胞的迁移和侵袭。CLDN1是miR-101-3p的靶标，而过表达CLDN1可以逆转miR-101-3p对细胞迁移和侵袭的抑制作用，而且，miR-101-3p抑制作用和CLDN1过表达可以逆转sh- XIST对PTC细胞的迁移和侵袭有抑制作用。XIST通过直接调节miR-101-3p / CLDN1轴来促进甲状腺乳头状癌细胞的迁移和侵袭，这是XIST调节PTC的新机制。miR-101-3p抑制和CLDN1过表达可以逆转sh-XIST对PTC细胞迁移和侵袭抑制的影响。XIST通过直接调节miR-101-3p / CLDN1轴来促进甲状腺乳头状癌细胞的迁移和侵袭，这是XIST调节PTC的新机制。miR-101-3p抑制和CLDN1过表达可以逆转sh-XIST对PTC细胞迁移和侵袭抑制的影响。XIST通过直接调节miR-101-3p / CLDN1轴来促进甲状腺乳头状癌细胞的迁移和侵袭，这是XIST调节PTC的新机制。