sFRP-4, a potential novel serum marker for chronic hepatitis B-related hepatocellular carcinoma

SAC3D1 activates Wnt/β‑catenin signalling in hepatocellular carcinoma

β‑catenin accumulates in hepatocellular carcinoma (HCC); therefore, understanding the mechanism of Wnt/β‑catenin pathway activation is important for HCC therapy. SAC3 domain containing 1 (SAC3D1) is involved in numerous types of cancer, such as gastric cancer. To the best of our knowledge, however, the role of SAC3D1 in HCC has not yet been elucidated. Here, the expression of SAC3D in HCC was examined by quantitative PCR, western blotting and immunohistochemistry. The function of SAC3D1 in HCC were examined using Cell Counting Kit‑8 and anchorage‑independent growth assay. It was found that the levels of SAC3D1 mRNA and protein were upregulated in HCC. When SAC3D1 was overexpressed, the proliferation of HCC cells was promoted; when the expression of SAC3D1 was disrupted, HCC cell growth was inhibited. When the molecular mechanism was investigated using immunoprecipitation, it was found that SAC3D1 interacted with axin, inhibiting ubiquitination of β‑catenin and elevating protein levels of β‑catenin. In summary, the present study revealed the promoting function of SAC3D1 in the progression of HCC. SAC3D1 may be a promising target for HCC therapy.

Clinical Value of Plasma Secreted Frizzled-Related Protein 4 in the Chronic Hepatitis B Virus Infection: A Cross-sectional Study

Background: Secreted frizzled-related protein 4 (sFRP4) is elevated in hepatocellular carcinoma (HCC) patients, suggesting that it can be served as a candidate marker for diagnosing HCC. However, little is known about its role in the different stages of chronic hepatitis B virus (HBV) infection. Objectives: This study was conducted to explore the clinical value of plasma sFRP4 in the different stages of chronic HBV infection. Methods: A total of 303 patients with chronic HBV infection were enrolled in this cross-sectional study. They were classified into the chronic hepatitis B (CHB), liver cirrhosis (LC), HCC, and acute-on-chronic liver failure (ACLF) groups on admission. Additionally, 30 healthy subjects were included in the healthy control (HC) group. The clinical value of plasma sFRP4 in the different stages of chronic HBV infection was analyzed. Results: There were 54, 85, 105, 59, and 30 cases in the CHB, LC, HCC, ACLF, and HC groups, respectively. ACLF group had the highest plasma sFRP4 levels compared to the CHB, LC, and HCC groups (all P < 0.001), followed by the HCC and LC groups. LC and HCC groups were found with up-regulated sFRP4 than the CHB group (all P < 0.05). High levels of plasma sFRP4 were recognized as an independent risk factor for distinguishing patients with ACLF from patients with CHB and LC [adjusted odds ratio (OR):1.005, 95% confidence interval (CI): 1.000 - 1.010, P = 0.043], with the area under the receiver operating characteristic curve (AUC) of 0.790 (95% CI: 0.726 - 0.844, P < 0.001). However, in patients with ACLF, plasma sFRP4 levels in the deteriorated group were higher than in the improved group, with a marginally significant difference (P = 0.071). The AUC for predicting the 90 days prognosis in patients with ACLF was 0.640 (P = 0.064). Conclusions: Plasma sFRP4 might be a biomarker to reflect the progression of chronic HBV infection. However, it was not significantly related to the prognosis in patients with ACLF; we did not find this, which may be due to the small sample size.

Demethylation of the SFRP4 Promoter Drives Gastric Cancer Progression via the Wnt Pathway

Wnt signaling is believed to be an important contributor to tumor development and has been reported to be modulated by secreted frizzled-related proteins (SFRP). Nevertheless, the role of secreted frizzled-related protein 4 (SFRP4) in tumorigenesis remains controversial. We aim to explore its biological function in gastric cancer. Genomes analysis based on the Gene Expression Omnibus (GEO) dataset was used to find the differential gene expression between different tumor-node-metastasis (TNM) stages of gastric cancer. IHC was used to determine the relationship between SFRP4 expression and clinicopathologic characteristics in patients with gastric cancer. The influence of SFRP4 on tumor progression was evaluated by CCK-8, colony formation, cell apoptosis, and cell cycle in vitro, as well as xenograft model in vivo. The methylation status of SFRPs was examined in gastric cancer specimens by quantitative methylation analysis. SFRP4 was most upregulated in advanced gastric cancer. High intratumoral SFRP4 expression, which was associated with tumor invasion and metastasis, was also a poor prognostic indicator for patients with gastric cancer. In vitro and in vivo studies revealed that SFRP4 could promote tumor growth; however, IWR-1 could suppress tumor growth mediated by SFRP4 overexpression. Mechanistic exploration found that SFRP4 was overexpressed by the decrease of promoter methylation and thus could competitively antagonize the inhibitory effect of SFRP1 on Wnt pathway activation and tumor progression in gastric cancer. IMPLICATIONS: In gastric cancer, the expression of SFRP4 was upregulated by decreased methylation. High intratumoral SFRP4 expression could activate the Wnt pathway to promote tumor progression and predict poor survival of patients with gastric cancer.

Tumor suppressor role of sFRP‑4 in hepatocellular carcinoma via the Wnt/β‑catenin signaling pathway

Hepatocellular carcinoma (HCC) is a malignant tumor located in the liver. Secreted frizzled-related protein 4 (sFRP-4) is associated with cancer occurrence, but the relationship between sFRP-4 and HCC is not completely understood. The present study aimed to investigate the role and mechanism underlying sFRP-4 in HCC. sFRP-4 mRNA expression levels were determined via reverse transcription-quantitative PCR and immunohistochemistry. The Cell Counting Kit-8 assay was performed to evaluate HCCLM3 and Huh7 cell viability. Moreover, HCCLM3 and Huh7 cell proliferation were assessed using the BrdU ELISA assay kit, and cell apoptosis was measured via flow cytometry. Western blotting was conducted to measure β-catenin and GSK-3β protein expression levels. The results demonstrated that sFRP-4 expression was significantly downregulated in HCC tissues and cells compared with adjacent healthy tissues and MIHA cells, respectively. Moreover, the results indicated that compared with the control group, sFRP-4 overexpression inhibited HCC cell viability and proliferation, and accelerated HCC cell apoptosis. Furthermore, the results suggested that sFRP-4 inhibited the Wnt/β-catenin signaling pathway by upregulating GSK-3β expression and downregulating β-catenin expression, thus restraining the malignant behavior of HCC cells. In conclusion, the present study indicated that sFRP-4 served a tumor suppressor role in HCC cells by restraining the Wnt/β-catenin signaling pathway.

Secreted frizzled related protein 4 (sFRP4) update: A brief review

Secreted frizzled-related proteins control a multitude of biological phenomena throughout development and adult life in humans. In parallel, aberrant gene expression and abnormal secreted protein levels accompany a wide range of pathologies in humans. In this review, we provide a brief introduction to sFRP4, an update of the pathways it's involved, its various physiological actions that are reported to contribute to diseases, outlining the importance of its wider research and specific modulation by pharmacologic interventions. First recognized as a novel molecule that co-purified with a disparate protein, its identity was based on its sequence homology to the frizzled receptors. Once multiple members of the family were cloned, their genetic loci, tissue and subcellular distributions were located. Nucleotide and amino acid sequences were characterized and homology to different organisms was found to be present that helped elucidate their actions. Following subsequent experimental studies, they were found to be secreted proteins with an affinity to bind to the Wnt ligands, participating in different developmental and adult homeostatic pathways by the virtue of their regulatory function to the Wnt signal transduction system. Secreted frizzled related protein 4 has garnered considerable attention in the recent years following breakthrough discoveries implicating them in the pathogenesis of various diseases. Studies investigating them can provide information not only regarding their association with a disease but can also help use them as potential biomarkers and therapeutic targets.

Secreted frizzled-related protein 2-mediated cancer events: Friend or foe?

Secreted frizzled-related protein (SFRP)2, an identified member of the SFRPs family of molecules, is often methylated in human cancers and its down-regulation is closely related to Wnt signaling activity and tumor progression. Although the blocker of the Wnt signaling has not been fully used in clinical trial, interest has been further enhanced by the realization of SFRPs' potential as targets to modulate Wnt signaling and cancer cell growth. Emerging evidence showed that SFRP2 was an anti-oncogene, however, a steady flow of research has indicated that it may also have tumor promotion effects in some cancer types. Furthermore, SFRP2 methylation was shown to accelerate cancer cell invasion and growth in tumor progression. In this review, we define recent understanding of the diverse roles of SFRP2 in tumorigenesis, and it might promote the development of novel drugs for curing cancer by targeting SFRP2.