RESUMEN
BACKGROUND: This study aimed to investigate the clinicopathological significance of sine oculis homeobox homolog 1 (SIX1) and eyes absent 1 (EYA1) in patients with chronic hepatitis B (CHB) and other liver diseases. METHODS: SIX1 and EYA1 levels were detected in human serum and liver tissues by enzyme linked immunosorbent assay (ELISA) and immunofluorescent staining method, respectively. RESULTS: The serum SIX1 and EYA1 levels in 313 CHB patients were 7.24±0.11 and 25.21±0.51 ng/mL, respectively, and these values were significantly higher than those in 33 healthy controls (2.84±0.15 and 13.11±1.01 ng/mL, respectively; P<0.05). Serum SIX1 and EYA1 levels were also markedly increased in patients with numerous other liver diseases, including liver fibrosis, hepatocellular carcinoma, fatty liver disease, alcoholic liver disease, fulminant hepatic failure, autoimmune liver disease, and hepatitis C, compared to the healthy controls (P<0.05). Dynamic observation of these proteins over time in 35 selected CHB patients revealed that SIX1 and EYA1 serum levels increased over an interval. Immunofluorescent staining revealed that both SIX1 and EYA1 were only expressed in hepatic stellate cells (HSCs), and their increased expression was evident in CHB liver tissue. CONCLUSIONS: SIX1 and EYA1 are novel biomarkers of liver damage in patients of CHB and other liver diseases, with potential clinical utility.
RESUMEN
Sine oculis homeobox homolog 1 (SIX1) is involved in the regulation of many kinds of tumors and plays an important role in the occurrence and development of breast cancer, but the exact mechanism remains to be explored. In this study, we analyzed the expression of SIX1 in breast cancer, and investigated the role of SIX1 in the proliferation and invasion of breast cancer cells. TCGA database and GEPIA2 showed that the expression of SIX1 in breast cancer was significantly higher than that in normal tissues, which was confirmed in different molecular subtypes of breast cancer, including Basal-like, HER2, Luminal A and Luminal B (P < 0. 05). Besides, the analysis of HPA database also showed that the expression of SIX1 was significantly upregulated in breast cancer, and the difference was statistically significant (P < 0. 001). After interfering with the expression of SIX1 in the breast cancer cell line MDA-MB-231 and overexpressing SIX1 in MCF-7, the growth curve and EdU results showed that the proliferation of breast cancer cells was inhibited after knocking down SIX1, while overexpression of SIX1 could promote the proliferation ability (the growth curve assays: P < 0. 05; EdU assays: P < 0. 001). Besides, Transwell assays showed that SIX1 could enhance the invasion ability of breast cancer cells (P < 0. 001). In TCGA database we defined the high and low expression populations according to the upper and lower quartiles of SIX1 gene expression, and differentially expressed genes were found to be associated with metabolism and stem cell regulatory pathways. For further confirmation, high-throughput RNA deep sequencing (RNA-seq) was conducted using SIX1-knockdown cells, and analysis also showed that SIX1 was closely related to metabolism, stem cell regulation and EMT pathways. We selected several representative genes, MYC, SNAI2 and EGFR, to examine their associations with SIX1 expression and prognosis in patients with clinical breast cancer using published GEO datasets and KM-plotter, we found that SIX1 was positively correlated with the expression of MYC, SNAI2 and EGFR, and the high expression of SIX1, MYC, SNAI2 and EGFR is not conducive to the survival of breast cancer patients. GCBI, GeneMANIA and String online tools were conducted to predict the associated genes, lncRNA and miRNA of SIX1. Collectively, our study initially revealed the role of SIX1 in breast cancer and its regulatory mechanism, providing new insights for further studies.
RESUMEN
MicroRNAs (miRNAs) are small yet versatile gene tuners that regulate a variety of cellular processes, including cell growth and proliferation. The aim of this study was to explore how miR-448-5p affects airway remodeling and transforming growth factor-ß1 (TGF-ß1)-stimulated epithelial-mesenchymal transition (EMT) by targeting Sine oculis homeobox homolog 1 (Six1) in asthma. Asthmatic mice models with airway remodeling were induced with ovalbumin solution. MiRNA expression was evaluated using quantitative real-time polymerase chain reaction. Transfection studies of bronchial epithelial cells were performed to determine the target genes. A luciferase reporter assay system was applied to identify whether Six1 is a target gene of miR-448-5p. In the current study, we found that miR-448-5p was dramatically decreased in lung tissues of asthmatic mice and TGF-ß1-stimulated bronchial epithelial cells. In addition, the decreased level of miR-448-5p was closely associated with the increased expression of Six1. Overexpression of miR-448-5p decreased Six1 expression and, in turn, suppressed TGF-ß1-mediated EMT and fibrosis. Next, we predicted that Six1 was a potential target gene of miR-448-5p and demonstrated that miR-448-5p could directly target Six1. An SiRNA targeting Six1 was sufficient to suppress TGF-ß1-induced EMT and fibrosis in 16HBE cells. Furthermore, the overexpression of Six1 partially reversed the protective effect of miR-448-5p on TGF-ß1-mediated EMT and fibrosis in bronchial epithelial cells. Taken together, the miR-448-5p/TGF-ß1/Six1 link may play roles in the progression of EMT and pulmonary fibrosis in asthma.