Differential expression of extracellular matrix-related genes DCN, EPHA4, FN1, SPARC, SPON2 and SPP1 in colorectal carcinogenesis
ONCOLOGY REPORTS
Authors: Zlajpah, Margareta; Hauptman, Nina; Bostjanacic, Emanuela; Zidar, Nina
Abstract
During colorectal carcinogenesis, a spectrum of lesions is formed with different malignant potentials and occasionally with ambiguous morphologic features. To identify novel biomarkers, we previously performed a bioinformatics study to detect differentially expressed genes between colorectal adenoma (CRA) and colorectal carcinoma (CRC). The present study validated the diagnostic and prognostic significance of 6 components of the extracellular matrix (ECM) that were identified in the previous bioinformatics analysis [decorin (DCN), erythropoietin-producing hepatoma receptor A4 (EPHA4), fibronectin 1 (FN1), secreted protein acidic and cysteine rich (SPARC), spondin 2 (SPON2) and secreted phosphoprotein 1 (SPP1)], by analyzing their gene and protein expression levels in all samples. A total of 60 formalin-fixed paraffin-embedded biopsy samples were included in the present study, from 40 patients with CRA, malignant polyps and CRC with and without lymph node metastases. The expression of the ECM-related genes was evaluated on the mRNA level using reverse transcription-quantitative PCR (RT-qPCR) and on the protein level using immunohistochemistry. RT-qPCR results revealed differential expression among the groups for all genes, except for EPHA4. Their expression proportionally increased with the level of malignancy. Among them, SPARC, SPON2 and SPP1 were differentially expressed between CRA and malignant polyps. Immunohistochemistry analysis revealed two patterns: Positive staining of SPON2 and SPP1 in epithelial cells of healthy mucosa and dysplastic glands of CRA and CRC, and positive staining of DCN and SPARC in the lamina propria in healthy mucosa and stroma of CRA and CRC. The intensity of staining increased with the severity of lesions. The present results suggested that ECM-related proteins may have an important role in the development of CRC, with a possible diagnostic use for differentiation among various lesions, such as between CRA and malignant polyps. However, no significant potential was detected for these genes to predict lymph node metastases in CRC.
Secreted Phosphoprotein 1 Promotes the Development of Small Cell Lung Cancer Cells by Inhibiting Autophagy and Apoptosis
PATHOLOGY & ONCOLOGY RESEARCH
Authors: Liu, Hong; Wei, Shufang; Zhang, Lei; Yuan, Chenxi; Duan, Yuanyuan; Wang, Qingwei
Abstract
This study aimed to investigate the expression of secreted phosphoprotein 1 (SPP1) on lung cancer cells and explore its underlying mechanism on autophagy and apoptosis which effect the development of lung cancer cells. GSE19804 related to lung cancer cells was screened from Gene Expression Omnibus (GEO) database, and we screened the 47 pairs of differential expressed mRNAs in lung cancer cells and adjacent tissues using microarray analysis. The expression of the core gene SPP1 was detected by qRT-PCR and western-blot. The transfection efficiency of lung cancer cells was detected by qRT-PCR and the expression of transfected group was tested by western-blot. Cell proliferation after transfection was tested by MTT assay and plate cloning experiment. The apoptosis rate of each transfection group was detected by flow cytometry. We use western-blot to test protein expression of autophagy-related proteins Beclin-1, LC3-I, LC3-II and p62 of each transfected group. Through analysis of GSE19804,the heat map showed SPP1 was the highest expressed in tumor tissues. qRT-PCR and western-blot detected SPP1 expression in lung cancer tissues was higher than that in normal adjacent tissues and was significantly increased in lung cancer cell lines. After transfection with pcDNA3.1-SPP1 (p-SPP1 group), siRNA1-SPP1 (siRNA1 group) and siRNA2-SPP1 (siRNA2 group), showed different expression of SPP1. Up-regulation of SPP1 enhanced cell viability and promoted tumor cell proliferation, while knockdown of SPP1 inhibited tumor cell proliferation. From the results of apoptosis rate, SPP1 inhibited the tumor cell apoptosis. However, in normal lung cell, SPP1 had no effect on cell proliferation and apoptosis. And to test autophagy-related proteins, we found that overexpression of SPP1 inhibited autophagy. High expression of SPP1 inhibited autophagy and apoptosis to promote the development of small cell lung cancer cells.