Low expression of secreted frizzled-related protein 4 in aggressive pituitary adenoma

Research progress on the role of the Wnt signaling pathway in pituitary adenoma

Pituitary adenoma (PA) is the third most common central nervous system tumor originating from the anterior pituitary, but its pathogenesis remains unclear. The Wnt signaling pathway is a conserved pathway involved in cell proliferation, Self-renewal of stem cells, and cell differentiation. It is related to the occurrence of various tumors, including PA. This article reviews the latest developments in Wnt pathway inhibitors and pathway-targeted drugs. It discusses the possibility of combining Wnt pathway inhibitors with immunotherapy to provide a theoretical basis for the combined treatment of PA.

Identification of Dysregulated Expression of G Protein Coupled Receptors in Endocrine Tumors by Bioinformatics Analysis: Potential Drug Targets?

Background: Many studies link G protein-coupled receptors (GPCRs) to cancer. Some endocrine tumors are unresponsive to standard treatment and/or require long-term and poorly tolerated treatment. This study explored, by bioinformatics analysis, the tumoral profiling of the GPCR transcriptome to identify potential targets in these tumors aiming at drug repurposing. Methods: We explored the GPCR differentially expressed genes (DEGs) from public datasets (Gene Expression Omnibus (GEO) database and The Cancer Genome Atlas (TCGA)). The GEO datasets were available for two medullary thyroid cancers (MTCs), eighty-seven pheochromocytomas (PHEOs), sixty-one paragangliomas (PGLs), forty-seven pituitary adenomas and one-hundred-fifty adrenocortical cancers (ACCs). The TCGA dataset covered 92 ACCs. We identified GPCRs targeted by approved drugs from pharmacological databases (ChEMBL and DrugBank). Results: The profiling of dysregulated GPCRs was tumor specific. In MTC, we found 14 GPCR DEGs, including an upregulation of the dopamine receptor (DRD2) and adenosine receptor (ADORA2B), which were the target of many drugs. In PGL, seven GPCR genes were downregulated, including vasopressin receptor (AVPR1A) and PTH receptor (PTH1R), which were targeted by approved drugs. In ACC, PTH1R was also downregulated in both the GEO and TCGA datasets and was the target of osteoporosis drugs. Conclusions: We highlight specific GPCR signatures across the major endocrine tumors. These data could help to identify new opportunities for drug repurposing.

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.

SFRP4 drives invasion in gastric cancer and is an early predictor of recurrence

OBJECTIVE

Gastric cancer patients generally have a poor outcome, particularly those with advanced-stage disease which is defined by the increased invasion of cancer locally and is associated with higher metastatic potential. This study aimed to identify genes that were functional in the most fundamental hallmark of cancer, namely invasion. We then wanted to assess their value as biomarkers of gastric cancer progression and recurrence.

DESIGN

Data from a cohort of patients profiled on cDNA expression arrays was interrogated using K-means analysis. This genomic approach classified the data based on patterns of gene expression allowing the identification of the genes most correlated with the invasion of GC. We evaluated the functional role of a key protein from this analysis in invasion and as a biomarker of recurrence after curative resection.

RESULTS

Expression of secreted frizzled-related protein 4 (SFRP4) was identified as directly proportional to gastric cancer invasion. This finding was validated in multiple, independent datasets and its functional role in invasion was also confirmed using invasion assays. A change in serum levels of SFRP4 after curative resection, when coupled with AJCC stage, can accurately predict the risk of disease recurrence after curative therapy in an assay we termed PredictR.

CONCLUSIONS

This simple ELISA-based assay can help predict recurrence of disease after curative gastric cancer surgery irrespective of adjuvant therapy. The results require further evaluation in a prospective trial but would help in the rational prescription of cancer therapies and surveillance to prevent under or over treatment of patients after curative resection.

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.

Increased β‑catenin and c-myc expression predict aggressive growth of non-functioning pituitary adenomas: An assessment using a tissue microarray-based approach

Non-functional pituitary adenomas (NFPAs) account for 80% of pituitary adenomas with the majority of these exhibiting recurrences post-surgery. Overexpression of β-catenin and c‑myc is common in numerous invasive tumors. The present study sought to investigate the correlation of β‑catenin and c‑myc expression levels with aggressive growth and recurrence of NFPAs, using immunohistochemical examination of tissue microarrays. Tissue microarrays comprised 212 NFPAs specimens and 10 healthy specimens as controls. NFPAs were categorized as non‑aggressive or aggressive. Immunohistochemical examination was performed to determine the expression of β‑catenin and c‑myc. Correlation of the expression levels of β‑catenin and c‑myc with clinicopathological parameters, including aggressiveness and recurrence, were assessed by univariate, multivariate and logistic regression analysis. Increased expression of β‑catenin and c‑myc was detected in the majority of aggressive NFPAs specimens (71.1 and 88.7%, respectively). There was a significant positive correlation between β‑catenin and c‑myc expression and aggressiveness [P=0.001, Odds Ratio (OR)=4.011; P<0.001, OR=30.833]. Only β‑catenin expression demonstrated a significant correlation with recurrence in NFPAs (P=0.021, OR=2.571). β‑catenin and c‑myc were demonstrated to be potential biomarkers for aggressive NFPAs and in the future, β-catenin may serve as a marker for aggressive behavior and recurrence in NFPAs.

Expression profile of long non-coding RNAs in colorectal cancer: A microarray analysis

Colorectal cancer (CRC) is one of the most prevalent malignant tumors and the second cause of cancer-related mortality worldwide. Due to increased morbidity and mortality rates, there is an urgent need to understand the pathogenesis of CRC, discover strategies that can improve diagnosis, and ultimately identify therapies targeting this disease. Over the past several years, research into tumor progression mechanisms has been devoted to identifying and understanding various coding and non-coding regions of the genome and how these genetic variants may affect tumorigenesis and progression. Recently, long non-coding RNAs (lncRNAs), which are non‑protein coding transcripts longer than 200 nucleotides, have emerged as a key aspect in tumor pathogenesis. In the present study, we examined the lncRNA and mRNA expression profiles in 4 patients with colon adenocarcinoma, with paired adjacent normal tissues as controls. Microarray data showed that a total of 3,523 lncRNAs and 2,515 mRNAs were consistently differentially expressed in the CRC tissues compared to adjacent normal tissues. Upon comparison of the differentially expressed transcripts between the groups, we identified 22 pathways which were related to the upregulated transcripts and 24 pathways that corresponded to the downregulated transcripts. Gene ontology analysis revealed that the upregulated transcripts were predominantly enriched in DNA metabolic processes, and the downregulated transcripts were predominantly enriched in organic hydroxyl compound metabolic processes. Coding-non-coding gene co-expression analysis showed that these differentially expressed lncRNAs were closely correlated with 'Wnt signaling pathway' components, whose aberrant activation plays a central role in CRC, indicating that a functional correlation exists between them. In conclusion, the results of the microarray and informatic analysis strongly suggest that lncRNA dysregulation is involved in the complicated process of CRC development, and may represent a novel class of diagnostic markers or therapeutic targets for CRC.

hTERT promoter methylation in pituitary adenomas

Telomerase reverse transcriptase (TERT) expression is a hallmark in tumorigenesis and upregulated due to mutations and methylation of the human (h)TERT promoter. As mutations are rare but methylation is common in pituitary adenomas (PA), we determined promoter methylation and its clinical impact in 85 primary and 15 recurrent PA by methylation-specific PCR. 40 females (47%) and 45 males (53%) with a median age of 53 years harboring micro-, macro-, and giant adenomas in 12, 82, and 6% were included (prolactinomas, corticotroph, somatotroph, gonadotroph, thyreotroph, plurihormonal, and null cell adenomas in 11, 18, 10, 29, 1, 10, and 21%, respectively). In primary diagnosed tumors, methylation rate was 27% and higher in males than in females (40 vs. 13%, p = 0.001) after uni- and multivariate analyses. Methylation differed among PA subtypes (0-42%, p = n.s.) and was not significantly correlated with tumor size, cavernous sinus invasion, or serum hormone levels. Ki67 labeling index and recurrence (N = 16, 19%) were independent of methylation. In recurrent tumors, methylation was similar to primary PA (N = 5/15, 33%) and remained unchanged along follow-up. Thus, while being commonly observed in PA, hTERT promoter methylation is stable along follow-up and independent of most clinical variables, PA subtype, proliferation, and without prognostic value.