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.
Keywords: biomarker, proliferation, migration, epithelial-mesenchymal transition, EMT, apoptosis