Analysis of the expression and mechanism of follistatin­like protein 1 in cervical cancer.

The abnormal expression of follistatin­like protein 1 (FSTL1) in various tumors is a crucial regulator of the biological process of tumorigenesis. Nonetheless, the regulatory role of FSTL1 in cervical cancer is yet to be elucidated. Hence, the present study aimed to explore the expression, function, and molecular mechanism of FSTL1 in cervical cancer. The expression of FSTL1 in normal and cervical cancer tissues was examined using quantitative reverse transcription­polymerase chain reaction and immunohistochemistry assays. The effects of abnormal expression of FSTL1 on cervical cancer cells were assessed using colony formation, MTT, wound­healing, Transwell, apoptosis, and nude mouse tumorigenicity assays. FSTL1­related molecular mechanisms were screened using gene chip analysis. Western blotting analysis was used to verify the regulatory mechanisms of FSTL1 in cervical cancer. The results indicated that the expression of FSTL1 was downregulated in cervical cancer tissues and that its downregulation was associated with tumor differentiation, pathologic type, and infiltration depth. Moreover, FSTL1 inhibited the proliferation, migration, and invasion of cervical cancer cells as well as xenograft tumor growth and promoted cell apoptosis. In addition, the findings of gene chip analysis suggested that the differentially expressed genes of FSTL1 were predominantly enriched in multiple signaling pathways, of which the insulin­like growth factor (IGF)­1 signaling pathway was significantly activated. Western blotting suggested the involvement of FSTL1 in the regulation of the IGF­1R/PI3K/AKT/BCL­2 signaling pathway. These data establish the downregulation of FSTL1 in cervical cancer tissues. FSTL1 inhibited the proliferation, migration, and invasion of cervical cancer cells and promoted their apoptosis. Furthermore, xenograft tumor growth in nude mice was inhibited. FSTL1 may be involved in the regulation of the IGF­1R/PI3K/AKT/BCL­2 signaling pathway in cervical cancer. Therefore, FSTL1 may be employed as a novel biomarker to determine the extent of disease progression in patients with cervical cancer.