Underexpression of INPPL1 is associated with aggressive clinicopathologic characteristics in papillary thyroid carcinoma

PURPOSE: To study the relationship between INPPL1 gene and clinicopathologic characteristics of papillary thyroid carcinoma (PTC). PATIENTS AND METHODS: INPPL1 expression in PTCs was tested by quantitative real-time reverse transcription PCR. The Cancer Genome Atlas (TCGA) RNA-seq data and our mRNA data were used to analyze and reveal the relationship between INPPL1 and aggressive clinicopathologic characteristics of PTC. RESULTS: When compared to normal thyroid tissues, INPPL1 was significantly downregulated in PTC tissues, as revealed by our data and TCGA data. INPPL1 underexpression was remarkably related to aggressive clinicopathologic characteristics such as lymph node metastasis (LNM), histological type, tumor size, mulitifocality, and disease stage in TCGA data. Meanwhile, LNM was confirmed to be associated with underexpression of INPPL1 in our data. In addition, logistic analysis clearly showed that underexpression of INPPL1 was an independent factor for LNM in PTC. CONCLUSION: INPPL1 may be a novel tumor suppressor gene in PTC, which was significantly correlated with aggressive clinicopathologic characteristics, especially LNM.