Bioinformatic Prediction of Novel Signaling Pathways of Apoptosis-inducing Factor, Mitochondrion-associated 3 (AIFM3) and Their Roles in Metastasis of Cholangiocarcinoma Cells.

Background/aim: We previously demonstrated that a mitochondrial protein, apoptosis-inducing factor, mitochondrion-associated 3 (AIFM3) is over-expressed in cholangiocarcinoma (CCA) and its serum levels can be a prognostic biomarker for CCA. To elucidate the functional roles of AIFM3 in CCA progression, we aimed to determine the signaling pathways of AIFM3 in CCA.

Materials And Methods: AIFM3 gene in CCA cells was silenced and AIFM3-related proteins were identified using mass spectrometry and bioinformatics tools. The relationships between AIFM3 and 441 related proteins were explored. To validate the functions of AIFM3, transwell migration/invasion assays were used.

Results: Bioinformatic analyses predicted that AIFM3 interacts with formin-like protein 3 (FMNL3) and is involved in tumor cell motilities. Online database analysis revealed higher AIFM3 mRNA expression levels in CCA, particularly with lymph node metastasis. After AIFM3 gene silencing, CCA cell migration/invasion was significantly decreased (p<0.001). Furthermore, AIFM3 expression levels were significantly associated with lymph node metastasis (p=0.0009) and shorter survival time (p=0.020).

Conclusion: The AIFM3 signaling pathway is mediated via FMNL3 and involved in metastasis, suggesting that AIFM3 might be a molecular target to prevent CCA metastasis.