The BMP inhibitor follistatin-like 1 (FSTL1) suppresses cervical carcinogenesis

FSTL1: A double-edged sword in cancer development

Flolistatin-related protein 1 (FSTL1), a secreted glycoprotein that is involved in many physiological functions, has attracted much interest and has been implicated in a wide range of diseases, including heart diseases and inflammatory diseases. In recent years, the involvement of FSTL1 in cancer progression has been implicated and researched. FSTL1 plays a contradictory role in cancer, depending on the cancer type as well as the contents of the tumor microenvironment. As reviewed here, the structure and distribution of FSTL1 are first introduced. Subsequently, the expression and clinical significance of FSTL1 in various types of cancer as a tumor enhancer or inhibitor are addressed. Furthermore, we discuss the functional role of FSTL1 in various processes that involve tumor cell proliferation, metastasis, immune responses, stemness, cell apoptosis, and resistance to chemotherapy. FSTL1 expression is tightly controlled in cancer, and a multitude of cancer-related signaling cascades like TGF-β/BMP/Smad signaling, AKT, NF-κB, and Wnt-β-catenin signaling pathways are modulated by FSTL1. Finally, FSTL1 as a therapeutic target using monoclonal antibodies is stated. Herein, we review recent findings showing the double-edged characteristics and mechanisms of FSTL1 in cancer and elaborate on the current understanding of therapeutic approaches targeting FSTL1.

Analysis of the expression and mechanism of follistatin‑like protein 1 in cervical cancer

The abnormal expression of follistatin‑like 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 transcription‑polymerase chain reaction and immunohistochemistry assays. The effects of abnormal expression of FSTL1 on cervical cancer cells were assessed using colony formation, MTT, wound‑healing, Transwell, apoptosis, and nude mouse tumorigenicity assays. FSTL1‑related 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 insulin‑like growth factor (IGF)‑1 signaling pathway was significantly activated. Western blotting suggested the involvement of FSTL1 in the regulation of the IGF‑1R/PI3K/AKT/BCL‑2 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 IGF‑1R/PI3K/AKT/BCL‑2 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.