The effect of S100A6 on nuclear translocation of CacyBP/SIP in colon cancer cells

The Role of S100A6 in Human Diseases: Molecular Mechanisms and Therapeutic Potential

S100A6, also known as calcyclin, is a low-molecular-weight Ca2+-binding protein from the S100 family that contains two EF-hands. S100A6 is expressed in a variety of mammalian cells and tissues. It is also expressed in lung, colorectal, pancreatic, and liver cancers, as well as other cancers such as melanoma. S100A6 has many molecular functions related to cell proliferation, the cell cycle, cell differentiation, and the cytoskeleton. It is not only involved in tumor invasion, proliferation, and migration, but also the pathogenesis of other non-neoplastic diseases. In this review, we focus on the molecular mechanisms and potential therapeutic targets of S100A6 in tumors, nervous system diseases, leukemia, endometriosis, cardiovascular disease, osteoarthritis, and other related diseases.

Knockout of Calcyclin Binding Protein Impedes the Growth of Breast Cancer Cells by Regulating Cell Apoptosis and β-Catenin Signaling

Breast invasive carcinoma (BRCA) is becoming the most common malignant disease worldwide, and there is intense interest in identifying diagnostic biomarkers that can be targeted for treatment of BRCA. Recent evidence has shown that calcyclin binding protein (CacyBP) can function as either a tumor promoter or suppressor during carcinogenesis. Data in The Cancer Genome Atlas (TCGA) database show that CacyBP is overexpressed in human BRCA tissues, and high levels of CacyBP are associated with shorter overall survival. Immunohistochemical staining has shown that CacyBP levels are high in cancer tissue samples and associated with a higher likelihood of disease progression. We, therefore, conducted a knockout assay to determine the role of CacyBP in the development of BRCA. Knockout of CacyBP significantly inhibited MCF7 cell proliferation and colony formation. Apoptosis was higher in CacyBP knockout cells compared with control cells. Microarray analysis showed that the CacyBP knockout caused dysregulation of numerous genes closely related to β-catenin signaling, whereas quantitative reverse-transcription PCR and immunoblotting showed that it to be inactivated. In summary, we conclude that when overexpressed, CacyBP acts as a potential oncogene for BRCA by regulating β-catenin signaling.

Tissue mRNA for S100A4, S100A6, S100A8, S100A9, S100A11 and S100P Proteins in Colorectal Neoplasia: A Pilot Study

S100 proteins are involved in the pathogenesis of sporadic colorectal carcinoma through different mechanisms. The aim of our study was to assess tissue mRNA encoding S100 proteins in patients with non-advanced and advanced colorectal adenoma. Mucosal biopsies were taken from the caecum, transverse colon and rectum during diagnostic and/or therapeutic colonoscopy. Another biopsy was obtained from adenomatous tissue in the advanced adenoma group. The tissue mRNA for each S100 protein (S100A4, S100A6, S100A8, S100A9, S100A11 and S100P) was investigated. Eighteen biopsies were obtained from the healthy mucosa in controls and the non-advanced adenoma group (six individuals in each group) and thirty biopsies in the advanced adenoma group (ten patients). Nine biopsies were obtained from advanced adenoma tissue (9/10 patients). Significant differences in mRNA investigated in the healthy mucosa were identified between (1) controls and the advanced adenoma group for S100A6 (p = 0.012), (2) controls and the non-advanced adenoma group for S100A8 (p = 0.033) and (3) controls and the advanced adenoma group for S100A11 (p = 0.005). In the advanced adenoma group, differences between the healthy mucosa and adenomatous tissue were found in S100A6 (p = 0.002), S100A8 (p = 0.002), S100A9 (p = 0.021) and S100A11 (p = 0.029). Abnormal mRNA expression for different S100 proteins was identified in the pathological adenomatous tissue as well as in the morphologically normal large intestinal mucosa.

S100A14 suppresses metastasis of nasopharyngeal carcinoma by inhibition of NF-kB signaling through degradation of IRAK1

Nasopharyngeal carcinoma (NPC) is a unique head and neck cancer with highly aggressive and metastatic potential in which distant metastasis is the main reason for treatment failure. Till present, the underlying molecular mechanisms of NPC metastasis remains poorly understood. Here, we identified S100 calcium-binding protein A14 (S100A14) as a functional regulator suppressing NPC metastasis by inhibiting the NF-kB signaling pathway and reversing the epithelial-mesenchymal transition (EMT). S100A14 was found to be downregulated in highly metastatic NPC cells and tissues. Immunohistochemical staining of 202 NPC samples revealed that lower S100A14 expression was significantly correlated with shorter patient overall survival (OS) and distant metastasis-free survival (DMFS). S100A14 was also found as an independent prognostic factor for favorable survival. Gain- and loss-of-function studies confirmed that S100A14 suppressed the in vitro and in vivo motility of NPC cells. Mechanistically, S100A14 promoted the ubiquitin-proteasome-mediated degradation of interleukin-1 receptor-associated kinase 1 (IRAK1) to suppress NPC cellular migration. Moreover, S100A14 and IRAK1 established a feedback loop that could be disrupted by the IRAK1 inhibitor T2457. Overall, our findings showed that the S100A14-IRAK1 feedback loop could be a promising therapeutic target for NPC metastasis.

Serum S100A6, S100A8, S100A9 and S100A11 proteins in colorectal neoplasia: results of a single centre prospective study

S100 proteins are involved in biological events related to colorectal carcinogenesis. Aim of this prospective study was to assess serum concentration of S100A6, A8, A9 and A11 proteins in patients with colorectal neoplasia. Eighty-four subjects were enrolled: 20 controls (average risk population with normal findings on colonoscopy; 7 men, 13 women, age 23-74, mean 55 ± 14), 20 patients with non-advanced colorectal adenoma (non-AA, 10 men, 10 women, age 41-82, mean 62 ± 11), 22 with advanced colorectal adenoma (AA, 15 men, 7 women, age 49-80, mean 64 ± 8) and 22 with colorectal cancer (CRC, 12 men, 10 women, age 49-86, mean 69 ± 10). Peripheral venous blood was obtained. Serum S100 proteins were investigated by enzyme immunoassay technique. Serum S100A6 was significantly lower in CRC (mean 8530 ± 4743 ng/L), p = .035 compared to controls (mean 11308 ± 2968 ng/L). Serum S100A8 was significantly higher in AA (median 11955 ng/L, IQR 2681-34756 ng/L), p = .009 and in CRC (median 27532 ng/L, IQR 6794-35092 ng/L), p < .001 compared to controls (median 2513 ng/L, IQR 2111-4881 ng/L). Serum S100A9 concentrations did not differ between any tested group and controls, p > .05. Serum concentration of S100A11 was significantly lower in non-AA (mean 3.5 ± 2.4 μg/L), p = .004 and in CRC (mean 3.4 ± 2.4 μg/L), p = .002 compared to controls (mean 5.9 ± 2.5 μg/L). Sensitivity and specificity for S100A8 protein in patients with CRC were 94% and 73%; positive predictive value 68% and negative predictive value 95%. Patients with colorectal neoplasia have significantly lower serum S100A6 and S100A11 levels, significantly higher S100A8 and unaltered serum S100A9 levels.

Bioinformatic analysis of Cacybp-associated proteins using human glioma databases

The ubiquitin-proteasome system is the primary cellular pathway for protein degradation, mediating 80% of intracellular protein degradation. Because of the widespread presence of ubiquitin-modified protein substrates, ubiquitination can regulate a variety of cellular activities including cell proliferation, apoptosis, autophagy, endocytosis, DNA damage repair, and immune responses. With the continuous generation of genomics data in recent years it has become particularly important to analyze these data effectively and reasonably. Cacybp forms a complex with the E3 ubiquitinated ligase Siah1 to participate in ubiquitination. We analyzed Cacybp-associated genes using the Gene Expression Omnibus (GEO) and CGGA (Chinese Glioma Genome Atlas) databases and identified 121 differentially expressed genes (DEGs), of which 46 were downregulated and 75 were upregulated. The biological processes, molecular functions, and protein-protein interaction (PPI) network of differential genes were analyzed by Cytoscape software and STRING software. We found no difference in Cacybp expression among different grades of gliomas and there was no significant association between the expression level of Cacybp and the prognosis of patients with glioma in LGG and GBM. © 2019 IUBMB Life, 1-8, 2019.