Identification of overexpressed genes in hepatocellular carcinoma, with special reference to ubiquitin-conjugating enzyme E2C gene expression

Department of Surgery and Molecular Oncology, Medical Institute of Bioregulation, Kyushu University, 4546 Tsurumihara, Beppu 874-0838, Japan.
International Journal of Cancer (Impact Factor: 5.09). 07/2007; 121(1):33-8. DOI: 10.1002/ijc.22605
Source: PubMed


This study consisted of 2 aims: (i) to determine genes associated with hepatocellular carcinoma (HCC) by microarray analysis; and (ii) to evaluate the clinicopathological significance of human ubiquitin-conjugating enzyme E2C (Ube2c) found to be overexpressed in HCC from microarray analysis. Laser microdissection and cDNA-microarray were performed to identify genes associated with HCC. We then focused on the Ube2c gene. Using real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR), Ube2c expression status and clinicopathological significance were studied in 65 clinical HCC samples. A number of genes upregulated in HCC cells compared to noncancerous liver cells were identified, one of which was the Ube2c gene. Ube2c gene expression in the cancer tissue was higher than in the corresponding noncancerous tissue in 62 of the 65 cases (95.4%, p < 0.01). Tumors with high Ube2c expression showed higher frequencies of tumor invasion to capsular formation (fc-inf), invasion to portal vein (vp) and tumor de-differentiation (p < 0.05). Patients with high Ube2c expression also showed significantly worse disease-free survival rates than those with low Ube2c expression (p < 0.01). In addition, Ube2c expression was found to be an independent prognostic factor for disease-free survival rate in multivariate analysis. We identified differentially expressed genes between HCC and normal liver tissues. Of those, the Ube2c gene appeared to be associated with HCC progression, and may be useful as a prognostic indicator for HCC patients.

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Available from: Fumiaki Tanaka, Nov 20, 2014
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    • "Total protein was extracted from each cell line. Aliquots of total protein (40 mg) were electrophoresed in 10% concentrated poly-acrylamide gel and then electrophoresed and then electroblotted as previously described (Ieta et al, 2007). "
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    ABSTRACT: Background: We previously conducted gene expression microarray analyses to identify novel indicators for colorectal cancer (CRC) metastasis and prognosis from which we identified PVT-1 as a candidate gene. PVT-1, which encodes a long noncoding RNA, mapped to chromosome 8q24 whose copy-number amplification is one of the most frequent events in a wide variety of malignant diseases. However, PVT-1 molecular mechanism of action remains unclear. Methods: We conducted cell proliferation and invasion assays using colorectal cancer cell lines transfected with PVT-1siRNA or negative control siRNA. Gene expression microarray analyses on these cell lines were also carried out to investigate the molecular function of PVT-1. Further, we investigated the impact of PVT-1 expression on the prognosis of 164 colorectal cancer patients by qRT–PCR. Results: CRC cells transfected with PVT-1 siRNA exhibited significant loss of their proliferation and invasion capabilities. In these cells, the TGF-β signalling pathway and apoptotic signals were significantly activated. In addition, univariate and multivariate analysis revealed that PVT-1 expression level was an independent risk factor for overall survival of colorectal cancer patients. Conclusion: PVT-1, which maps to 8q24, generates antiapoptotic activity in CRC, and abnormal expression of PVT-1 was a prognostic indicator for CRC patients.
    British Journal of Cancer 11/2013; 110(1). DOI:10.1038/bjc.2013.698 · 4.84 Impact Factor
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    • "Total protein was extracted from PRRX1- expressing cell lines and mock cell lines. Aliquots of total protein (40 mg) were electrophoresed in 10% concentrated polyacrylamide gel, and then electrophoresed and electroblotted as previously described (Ieta et al, 2007). Detailed information can be found in the Supplementary Material. "
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    ABSTRACT: Background: Paired related homoeobox 1 (PRRX1) has been identified as a new epithelial-mesenchymal transition (EMT) inducer in breast cancer. However, the function of PRRX1 in colorectal cancer (CRC) has not been elucidated. Methods: We utilised ectopic PRRX1-expressing cell lines to analyse the function of PRRX1 in CRC. The clinical significance of PRRX1 was also examined on three independent CRC case sets. Results: PRRX1 induced EMT and the stem-like phenotype in CRC cells. In contrast to studies of breast cancer, abundant expression of PRRX1 was significantly associated with metastasis and poor prognosis in CRC. Conclusion: PRRX1 is an indicator of metastasis and poor prognosis in CRC cases. Further investigation is required to uncover the signalling network regulating PRRX1.
    British Journal of Cancer 06/2013; 109(2). DOI:10.1038/bjc.2013.339 · 4.84 Impact Factor
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    • "Recent data has shown that aberrantly high expression of UBE2C contributes to tumorigenesis, and has revealed its potential as a biomarker for cancer prognosis [5]. Abnormally high UBE2C expression was observed in various human solid cancers in the liver [6], thyroid [7], breast [8], colon [9,10], cervix [11], lung [12] and brain [13], and UBE2C expression was positively correlated with invasion depth and tumor node metastasis (TNM) stage in some tumors. Furthermore, inhibition of UBE2C expression induced by RNA interference significantly reduced the proliferation of cancer cells [7,14] and enhanced cell apoptosis in vitro[15]. "
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    ABSTRACT: Background Overexpression of ubiquitin-conjugating enzyme 2C (UBE2C) has been detected in many types of human cancers, and is correlated with tumor malignancy. However, the role of UBE2C in human nasopharyngeal carcinoma (NPC) is unclear. In this study, we investigated the role of aberrant UBE2C expression in the progression of human NPC. Methods Immunohistochemical analysis was performed to detect UBE2C protein in clinical samples of NPC and benign nasopharyngeal tissues, and the association of UBE2C expression with patient clinicopathological characteristics was analyzed. UBEC2 expression profiles were evaluated in cell lines representing varying differentiated stages of NPC and immortalized nasopharyngeal epithelia NP-69 cells using quantitative RT-PCR, western blotting and fluorescent staining. Furthermore, UBE2C was knocked down using RNA interference in these cell lines and proliferation and cell cycle distribution was investigated. Results Immunohistochemical analysis revealed that UBE2C protein expression levels were higher in NPC tissues than in benign nasopharyngeal tissues (P<0.001). Moreover, high UBE2C protein expression was positively correlated with tumor size (P=0.017), lymph node metastasis (P=0.016) and distant metastasis (P=0.015) in NPC patients. In vitro experiments demonstrated that UBE2C expression levels were inversely correlated with the degree of differentiation of NPC cell lines, whereas UBE2C displayed low level of expression in NP-69 cells. Knockdown of UBE2C led to significant arrest at the S and G2/M phases of the cell cycle, and decreased cell proliferation was observed in poorly-differentiated CNE2Z NPC cells and undifferentiated C666-1 cells, but not in well-differentiated CNE1 and immortalized NP-69 cells. Conclusions Our findings suggest that high expression of UBE2C in human NPC is closely related to tumor malignancy, and may be a potential marker for NPC progression.
    BMC Cancer 04/2013; 13(1):192. DOI:10.1186/1471-2407-13-192 · 3.36 Impact Factor
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