IFITM1 as a modulator of surfaceome dynamics and aggressive phenotype in cervical cancer cells

Interferon-induced transmembrane proteins (IFITMs) are frequently overexpressed in cancer cells, including cervical carcinoma cells, and play a role in the progression of various cancer types. However, their mechanisms of action remain incompletely understood. In the present study, by employing a combination of surface membrane protein isolation and quantitative mass spectrometry, it was comprehensively described how the IFITM1 protein influences the composition of the cervical cancer cell surfaceome. Additionally, the effects of interferon-γ on protein expression and cell surface exposure were evaluated in the presence and absence of IFITM1. The IFITM1-regulated membrane and membrane-associated proteins identified are involved mainly in processes such as endocytosis and lysosomal transport, cell-cell and cell-extracellular matrix adhesion, antigen presentation and the immune response. To complement the proteomic data, gene expression was analyzed using reverse transcription-quantitative PCR to distinguish whether the observed changes in protein levels were attributable to transcriptional regulation or differential protein dynamics. Furthermore, the proteomic and gene expression data are supported by functional studies demonstrating the impact of the IFITM1 and IFITM3 proteins on the adhesive, migratory and invasive capabilities of cervical cancer cells, as well as their interactions with immune cells.干扰素诱导跨膜蛋白（interferon-induced transmembrane proteins, IFITMs）在包括宫颈癌细胞在内的多种癌细胞中常出现过表达，并参与多种癌症类型的进展过程。然而，其具体作用机制仍未完全阐明。本研究通过结合细胞膜表面蛋白分离技术与定量质谱分析，全面解析了IFITM1蛋白对宫颈癌细胞表面蛋白质组组成的调控作用。此外，本研究还评估了在IFITM1存在与缺失的情况下，干扰素-γ（interferon-γ, IFN-γ）对蛋白质表达及细胞表面暴露水平的影响。本研究鉴定得到的受IFITM1调控的膜蛋白及膜相关蛋白，主要参与内吞作用、溶酶体运输、细胞-细胞及细胞-细胞外基质黏附、抗原呈递与免疫应答等生物学过程。为补充蛋白质组学数据，本研究采用逆转录定量PCR（reverse transcription-quantitative PCR, RT-qPCR）分析基因表达水平，以区分观察到的蛋白质水平变化是源于转录调控还是蛋白质动态平衡差异。此外，蛋白质组学与基因表达数据得到了功能实验的验证：这些实验证实了IFITM1与IFITM3蛋白对宫颈癌细胞黏附、迁移及侵袭能力的影响，以及这些蛋白与免疫细胞的相互作用。