Hepatoma-derived growth factor functions as an unfavorable prognostic marker of human gliomas

Hepatoma-Derived Growth Factor: An Overview and Its Role as a Potential Therapeutic Target Molecule for Digestive Malignancies

Hepatoma-derived growth factor (HDGF) was identified in research seeking to find a novel growth factor for hepatoma cells. Subsequently, four HDGF-related proteins were identified, and these proteins are considered to be members of a new gene family. HDGF has a growth-stimulating role, an angiogenesis-inducing role, and a probable anti-apoptotic role. HDGF is ubiquitously expressed in non-cancerous tissues, and participates in organ development and in the healing of damaged tissues. In addition, the high expression of HDGF was reported to be closely associated with unfavorable clinical outcomes in several malignant diseases. Thus, HDGF is considered to contribute to the development and progression of malignant disease. We herein provide a brief overview of the factor and its functions in relation to benign and malignant cells. We also describe its possible role as a target molecule for digestive malignancies.

MicroRNA-939 Directly Targets HDGF to Inhibit the Aggressiveness of Prostate Cancer via Deactivation of the WNT/β-Catenin Pathway

Purpose

MicroRNA-939 (miR-939) has crucial roles in several types of human cancer. However, the expression profile and precise functions of miR-939 in prostate cancer (PCa) are still unclear. This study aimed to determine miR-939 expression in PCa and explore its roles in PCa tumorigenesis.

Methods

miR-939 expression was determined in PCa tissues and cell lines using reverse transcription–quantitative polymerase chain reaction. Cell Counting Kit-8, colony formation, and flow cytometric assays were used to determine the role of miR-939 in PCa cell proliferation and apoptosis in vitro, whereas a tumor xenograft model was generated to evaluate the effect of miR-939 on tumor growth in vivo. Transwell assays were performed to investigate whether miR-939 affects the migration and invasiveness of PCa cells.

Results

miR-939 was found to be downregulated in PCa tissues and cell lines, and this downregulation was significantly correlated with tumor stage and lymphatic metastasis. Patients with PCa exhibiting low miR-939 expression had shorter overall survival than those exhibiting high miR-939 expression. Exogenous miR-939 expression suppressed PCa cell proliferation, colony formation, migration, and invasion in vitro; enhanced apoptosis in vitro; and decreased tumor growth in vivo. Investigation of the underlying molecular mechanisms revealed hepatoma-derived growth factor (HDGF) as a direct target gene of miR-939 in PCa. HDGF was found to be significantly upregulated in PCa tissues, and its expression was inversely correlated with miR-939 expression. HDGF silencing and miR-939 upregulation showed similar effects in PCa. Restored HDGF expression counteracted the tumor-suppressive activity of miR-939 overexpression in PCa cells. Furthermore, ectopic miR-939 expression inhibited the WNT/β-catenin pathway activation in PCa both in vitro and in vivo by downregulating HDGF.

Conclusion

miR-939 functions as a tumor suppressor during PCa tumorigenesis by directly targeting HDGF and deactivating the WNT/β-catenin pathway, suggesting the miR-939/HDGF/WNT/β-catenin pathway as an effective target for PCa therapy.