MFAP2 is a Potential Diagnostic and Prognostic Biomarker That Correlates with the Progression of Papillary Thyroid Cancer

Background: Microfibril-associated protein 2 (MFAP2) is a protein coding gene that exerts important phenotypic effects on cell motility, and increasing research has indicated that MFAP2 was correlated with many cancers. However, the functional and potential clinical role of MFAP2 in papillary thyroid cancer (PTC) has not yet been verified. Materials and Methods: We performed whole transcriptome sequencing on 78 paired PTC tissues and corresponding adjacent normal tissues and found that MFAP2 was highly expressed in PTC tissues. Then, we analyzed the expression of MFAP2 and its relation with the clinicopathological features of PTC in The Cancer Genome Atlas (TCGA) PTC genomic dataset. We detected MFAP2 expression in 40 paired PTC tissues and corresponding adjacent normal tissues through RT-qPCR (real time-quantitative polymerase chain reaction) to validate the sequencing data and TCGA cohort. Cell functional assays were performed to elucidate the function of MFAP2 in PTC cells, Western blot assay was performed to explore the correlation between MFAP2 and EMT (epithelial-mesenchymal transition)-related proteins. Results: Statistical analysis showed that MFAP2 was obviously upregulated in PTC tissues compared to matched normal tissues, and the expression levels of MFAP2 in PTC tissues were strongly related with lymph node metastasis (p=0.016). The results of RT-qPCR of our own tissue specimens showed the same conclusions as that in TCGA dataset. The results of functional assays in PTC cell lines showed that MFAP2 could promote proliferation, colony formation, migration and invasion abilities and decrease the apoptotic rate in PTC cells. Western Blot assay showed that MFAP2 could regulate the expression of EMT-related proteins. Conclusion: MFAP2 increases the proliferation, motility and decreases the apoptosis of PTC cells, and might be a potential therapeutic target for papillary thyroid cancer.