Identification of NEO1 as a prognostic biomarker and its effects on the progression of colorectal cancer.

BACKGROUND: Due to the high morbidity and poor clinical outcomes, early predictive and prognostic biomarker identification is desiderated in colorectal cancer (CRC). As a homologue of the Deleted in Colorectal Cancer (DCC) gene, the role of Neogenin-1 (NEO1) in CRC remained unveiled. This study was designed to probe into the effects and potential function of NEO1 in CRC. METHODS: Online databases, Gene Set Enrichment Analysis (GSEA), quantitative real-time PCR and western blotting were used to evaluate NEO1 expression in colorectal cancer tissues. Survival analysis was performed to predict the prognosis of CRC patients based on NEO1 expression level. Then, cell proliferation was detected by colony formation and Cell Counting Kit 8 (CCK-8) assays. CRC cell migration and invasion were examined by transwell assays. Finally, we utilized the Gene Set Variation Analysis (GSVA) and GSEA to dig the potential mechanisms of NEO1 in CRC. RESULTS: Oncomine database and The Cancer Genome Atlas (TCGA) database showed that NEO1 was down-regulated in CRC. Further results validated that NEO1 mRNA and protein expression were both significantly lower in CRC tumor tissues than in the adjacent tissues in our clinical samples. NEO1 expression was decreased with the progression of CRC. Survival and other clinical characteristic analyses exhibited that low NEO1 expression was related with poor prognosis. A gain-of-function study showed that overexpression of NEO1 restrained proliferation, migration and invasion of CRC cells while a loss-of-function showed the opposite effects. Finally, functional pathway enrichment analysis revealed that NEO1 low expression samples were enriched in inflammation-related signaling pathways, EMT and angiogenesis. CONCLUSION: A tumor suppressor gene NEO1 was identified and verified to be correlated with the prognosis and progression of CRC, which could serve as a prognostic biomarker for CRC patients.

Expression of Stanniocalcin 2 in Breast Cancer and Its Clinical Significance.

This study aims to explore the expression of stanniocalcin 2 (STC2) gene in breast cancer and its clinical significance. Female patients with breast cancer from Zhongnan Hospital of Wuhan University admitted during March 2014 to October 2014 were enrolled in this study. All the tissues used in this experiment included 50 cases of breast cancer tissues and corresponding 50 cases of paracancer normal breast tissues with complete patients' information. The real-time quantitative polymerase chain reaction (qPCR) was applied to detect the expression of STC2 gene in 50 cases of breast cancer and paracancer normal breast tissues. The results showed that the expression level of STC2 gene in 50 cases of breast cancer tissues was significantly higher than that in paracancer normal breast tissues (P<0.001). The expression of STC2 gene was correlated with lymph node metastasis, distant metastasis, TNM stage and histological grade (P<0.001). The expression level of STC2 gene was significantly higher in breast cancer tissues with higher expression of Ki-67 (P<0.001). The expression level of STC2 gene was significantly higher in estrogen receptor (ER) positive breast cancer tissues than in ER negative ones (P<0.001). However, different groups of age, pathological type, tumor size, PR expression and human epidermal growth factor receptor-2 (HER2) expression did not show significant differences in STC2 expression (P>0.05). In conclusion, the abnormal overexpression of STC2 gene may play a role in the development and progression of breast cancer, and it can be used as an independent metastasis and prognostic factor of breast cancer. In addition, STC2 gene probably promotes the development and metastasis of breast cancer by interacting with estrogen and ER, and it may become a new direction for breast cancer endocrine therapy.

DJ-1 Alters Epirubicin-induced Apoptosis via Modulating Epirubicinactivated Autophagy in Human Gastric Cancer Cells.

Epirubicin, which is a conventional chemotherapeutic drug for gastric cancer, has innate and adaptive chemoresistance. Recent studies revealed that epirubicin could induce autophagy as a defensive mechanism in drug resistance of mammary carcinoma. Another study implied that DJ-1 may be a chemoresistance-related gene. But the association between DJ-1 and drug resistance of epirubicin in gastric cancer is still ambiguous. In the present report, we explored whether and how DJ-1 conduced to epirubicin-induced apoptosis in gastric cancer. Epirubicin dose-dependently increased the expression of DJ-1 and induced autophagy. Knockdown of DJ-1 notably enhanced epirubicin-induced cell apoptosis, whereas overexpression of DJ-1 attenuated epirubicin-induced cell apoptosis. Further studies revealed that down-regulation of DJ-1 modulated epirubicinactivated autophagy which augmented epirubicin-induced apoptosis. In conclusion, our results validated that DJ-1 reduced epirubicin-induced apoptosis in gastric cancer cells via modulating epirubicin-activated autophagy.

SLC38A1 promotes proliferation and migration of human colorectal cancer cells.

Current studies have demonstrated that SLC38A1 proteins play a causal role in neoplastic cell transformation. The twofold aim of this study was to provide insight into whether a variance in the expression of SLC38A1 exists between human colorectal cancer and healthy human tissues and to determine how silencing or overexpressing the SLC38A1 gene could affect the proliferation, viability and migration of colorectal cancer cells. Immunohistochemical staining was used to analyze the expression of SLC38A1 in colorectal cancer tissues and adjacent normal mucosa in 77 patients who underwent surgical resection. The expression of SLC38A1 in colorectal cancer tissues and cell lines was detected using RT-PCR and Western blotting. Two colorectal cancer cell lines SW480 and HCT116 were used to examine whether silencing SLC38A1 with siRNA and overexpressing SLC38A1 with shRNA could affect cell viability and migration. As a result, the SLC38A1 protein was very low or undetectable in the normal colon mucosa. In contrast, strong staining of SLC38A1 protein was found in the cytoplasm in 79.2% colorectal cancer samples. More pronounced SLC38A1 expression in colorectal cancer tissues was significantly associated with tumor node metastasis (TNM) stage. Inhibition of SLC38A1 reduced tumour growth and suppressed proliferation and migration of SW480 cells. In contrast, overexpression of SLC38A1 had the opposite effects on HCT116 cells. SLC38A1 is overexpressed in colorectal cancer, which suggests that it is associated with tumour progression. These results encourage the exploration of SLC38A1 as a target for intervention in colorectal cancer.

Knockdown of GRHL3 inhibits activities and induces cell cycle arrest and apoptosis of human colorectal cancer cells.

The Grainyhead-like 3 (GRHL3) is involved in epidermal barrier formation, neural tube closure and wound repair. Previous studies have suggested that GRHL3 has been linked to many different types of cancers. However, to date, its effects on human colorectal cancer (CRC) has not been clarified yet. Our microarray analysis has indicated predominant GRHL3 expression in CRC. The purpose of this study was to investigate the expression and significance of GRHL3 in CRC tumorigenesis using CRC tissues and paired paracancerous tissues, as well as using distinct CRC cell lines (HT29 and DLD1). We observed increased GRHL3 expression at both mRNA and protein levels in CRC tissues and CRC cell lines using quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting. Moreover, silencing GRHL3 with siRNA could suppress CRC cell proliferation, viability and migration in vitro. We also found that knockdown of GRHL3 could promote cell cycle arrest at G0/G1 phase in HT29 cells and DLD1 cells, and induce cell apoptosis in HT29 cells. Together, our study revealed the down-regulation of GRHL3 in vitro could inhibit CRC cell activity and trigger cell cycle arrest at G0/G1 phase and apoptosis.

Inhibition of adhesion and metastasis of HepG2 hepatocellular carcinoma cells in vitro by DNA aptamer against sialyl Lewis X.

The sialyl Lewis X (SLex) antigen encoded by the FUT7 gene is the ligand of endotheliam-selectin (E-selectin). The combination of SLex antigen and E-selectin represents an important way for malignant tumor metastasis. In the present study, the effect of the SLex-binding DNA aptamer on the adhesion and metastasis of hepatocellular carcinoma HepG2 cells in vitro was investigated. Reverse transcription-polymerase chain reaction (RT-PCR) and immunofluorescence staining were conducted to detect the expression of FUT7 at both transcriptional and translational levels. The SLex expression in HepG2 cells treated with different concentrations of SLex-binding DNA aptamer was detected by flow cytometry. Besides, the adhesion, migration, and invasion of HepG2 cells were measured by cell adhesion assay, and the Transwell migration and invasion assay. The results showed that the FUT7 expression was up-regulated at both mRNA and protein levels in HepG2 cells. SLex-binding DNA aptamer could significantly decrease the expression of SLex in HepG2 cells. The cell adhesion assay revealed that the SLex-binding DNA aptamer could effectively inhibit the interactions between E-selectin and SLex in the HepG2 cells. Additionally, SLex-binding DNA aptamers at 20 nmol/L were found to have the similar effect to the monoclonal antibody CSLEX-1. The Transwell migration and invasion assay revealed that the number of penetrating cells on the down-side of Transwell membrane was significantly less in cells treated with 5, 10, 20 nmol/L SLex-binding DNA aptamer than those in the negative control group (P<0.01). Our study demonstrated that the SLex-binding DNA aptamer could significantly inhibit the in vitro adhesion, migration, and invasion of HepG2 cells, suggesting that the SLex-binding DNA aptamer may be used as a potential molecular targeted drug against metastatic hepatocellular carcinoma.