The present study aimed to identify the expression of key mRNAs as prognostic factors for papillary thyroid cancer (PTC) using integrated bioinformatic analyses and in vitro assays. Using mRNA sequencing data from The Cancer Genome Atlas, we found that alpha-1 type I collagen (COL1A1), an extracellular matrix protein, was significantly overexpressed in PTC, and its expression was correlated with a lower probability of disease-free survival and clinical characteristics of PTC patients by applying Kaplan-Meier curves and logistic regression analysis. Furthermore, we performed in vitro assays, including cell proliferation, colony formation, transwell, and wound healing assays, to validate the role of COL1A1 in the progression and metastasis of PTC. Downregulation of COL1A1 with siRNA inhibited cell proliferation, invasion, and migration. COL1A1 is a potential prognostic biomarker and target for preventing the recurrence of PTC. (C) 2019 Elsevier Inc. All rights reserved.