Liyan Chen

Clinical implications of high NQO1 expression in breast cancers

BackgroundNAD (P) H: quinone oxidoreductase 1 (NQO1) is a xenobiotic metabolizing enzyme that detoxifies chemical stressors and antioxidants, providing cytoprotection in normal tissues. However, high-level expression of NQO1 has been correlated with numerous human malignancies, suggesting a role in carcinogenesis and tumor progression. This study aimed to explore the clinicopathological significance of NQO1 and as a prognostic determinant in breast cancer.MethodsA total of 176 breast cancer patients with strict follow-up, 45 ductal carcinoma in situ (DCIS), 22 hyperplasia and 52 adjacent non-tumor breast tissues were selected for immunohistochemical staining of NQO1 protein. Immunofluorescence staining was also performed to detect the subcellular localization of NQO1 protein in MCF-7 breast cancer cells. Eight fresh breast cancers paired with adjacent non-tumor tissues were quantified using real time RT-PCR (qRT-PCR) and western blot. The correlations between NQO1 overexpression and the clinical features of breast cancer were evaluated using chi-square test and Fisher’s exact tests. The survival rate was calculated using the Kaplan–Meier method, and the relationship between prognostic factors and patient survival was also analyzed by the Cox proportional hazards models.ResultsNQO1 protein showed a mainly cytoplasmic staining pattern in breast cancer. The strongly positive rate of NQO1 protein was 61.9% (109/176) in breast cancer, and was significantly higher than in DCIS (31.1%, 14/45), hyperplasia tissues (13.6%, 3/22) and adjacent non-tumor tissues (13.5%, 7/52). High-level expression of NQO1 protein was correlated with late clinical stage, poor differentiation, lymph node metastasis, Her2 expression and disease-free and 10-year overall survival rates in breast cancer. Moreover, multivariate analysis suggested that NQO1 emerged as a significant independent prognostic factor along with clinical stage and Her2 expression status in patients with breast cancer.ConclusionsHigh-level expression of NQO1 appears to be associated with breast cancer progression, and may be a potential biomarker for poor prognostic evaluation of breast cancers.

Ezrin contributes to cervical cancer progression through induction of epithelial-mesenchymal transition

Cervical cancer is the third most common cancer in females worldwide. The treatment options for advanced cervical cancer are limited, leading to high mortality. Ezrin is a membrane-cytoskeleton-binding protein recently reported to act as a tumor promoter, and we previously indicated that the aberrant localization and overexpression of Ezrin could be an independent effective biomarker for prognostic evaluation of cervical cancers. In this study, we identified Ezrin as a regulator of epithelial-mesenchymal transition (EMT) and metastasis in cervical cancer. Ezrin knock-down inhibited anchorage-independent growth, cell migration, and invasion of cervical cancer cell lines in vitro and in vivo. EMT was inhibited in Ezrin-depleted cells, with up-regulation of E-cadherin and Cytokeratin-18 (CK-18) and down-regulation of mesenchymal markers. Ezrin knock-down also induced Akt phosphorylation. These results implicate Ezrin as an EMT regulator and tumor promoter in cervical cancer, and down-regulation of Ezrin suppressed cervical cancer progression, possibly via the phosphoinositide 3-kinase/Akt pathway. Furthermore, the expression pattern of Ezrin protein was closely related with the lymphovascular invasion status of cervical cancer by immunohistochemistry, and the survival analysis revealed that the cervical cancer patients with the perinuclear Ezrin expression pattern had longer survival time than those with the cytoplasmic Ezrin expression pattern. Ezrin thus represents a promising target for the development of novel and effective strategies aimed at preventing the progression of cervical cancer.

High expression of leucine zipper-EF-hand containing transmembrane protein 1 predicts poor prognosis in head and neck squamous cell carcinoma.

Leucine zipper-EF-hand containing transmembrane protein 1 (LETM1) is a mitochondrial inner membrane protein and plays an important role in mitochondrial ATP production and biogenesis. High expression levels of LETM1 have been correlated with numerous human malignancies. This study explored the clinicopathological significance of LETM1 expression as a prognostic determinant in head and neck squamous cell carcinoma (HNSCC). HNSCC samples from 176 patients were selected for immunohistochemical staining of LETM1 protein. Correlations between LETM1 overexpression and clinicopathological features of HNSCC were evaluated by Chi-squared tests and Fishers exact tests, and relationships between prognostic factors and patient survival were analyzed using Cox proportional hazards models. Our results demonstrated that the strongly positive rate of LETM1 protein was 65.3% in HNSCC, which was significantly higher than in either adjacent nontumor tissue (25.0%) or normal squamous epithelia (6.7%). LETM1 overexpression correlated with poor differentiation, presence of lymph node metastasis, advanced stage, absence of chemoradiotherapy, and 5-year disease-free survival and overall survival rates in HNSCC. Further analysis showed that high LETM1 expression, advanced stage, and nonchemoradiotherapy were significant independent risk factors for mortality in HNSCC. In conclusion, LETM1 plays an important role in the progression of HNSCC and is an independent poor prognostic factor for HNSCC.

DEK promoted EMT and angiogenesis through regulating PI3K/AKT/mTOR pathway in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is a highly aggressive subtype of breast cancer associated with poor prognosis. As an oncogene, DEK involves in regulation of various cellular metabolisms and plays an important role in tumor growth and progression. Increasing evidences suggested that abnormal expression of DEK is closely related to multiple malignant tumors. However, the possible involvement of DEK in epithelial to mesenchymal transition (EMT) and angiogenesis in TNBC remains unclear. In the present study, we revealed that the over-expression of DEK was significantly correlated with clinical stage, differentiation, and lymph node (LN) metastasis of TNBC and indicated poor overall survival of TNBC patients. Moreover, we demonstrated that DEK depletion could significantly reduce cell proliferation, migration, invasion and angiogenesis in vitro. We also found that DEK promoted cancer cell angiogenesis and metastasis by activating the PI3K/AKT/mTOR pathway. Furthermore, we revealed the inhibitory effect of DEK depletion on tumor growth and progression in a xenograft tumor model in mice. These data indicated that DEK promotes TNBC cell proliferation, angiogenesis, and metastasis via PI3K/AKT/mTOR signaling pathway, and therefore, it might be a potential target in TNBC therapy.

β-lapachone suppresses tumour progression by inhibiting epithelial-to-mesenchymal transition in NQO1-positive breast cancers

NQO1 is a FAD-binding protein that can form homodimers and reduce quinones to hydroquinones, and a growing body of evidence currently suggests that NQO1 is dramatically elevated in solid cancers. Here, we demonstrated that NQO1 was elevated in breast cancer and that its expression level was positively correlated with invasion and reduced disease free survival (DFS) and overall survival (OS) rates. Next, we found that β-lapachone exerted significant anti-proliferation and anti-metastasis effects in breast cancer cell lines due to its effects on NQO1 expression. Moreover, we revealed that the anti-cancer effects of β-lapachone were mediated by the inactivation of the Akt/mTOR pathway. In conclusion, these results demonstrated that NQO1 could be a useful prognostic biomarker for patients with breast cancer, and its bioactivatable drug, β-lapachone represented a promising new development and an effective strategy for indicating the progression of NQO1-positive breast cancers.

Clinicopathological implications of NQO1 overexpression in the prognosis of pancreatic adenocarcinoma

Nicotinamide adenine dinucleotide phosphate: quinone oxidoreductase 1 (NQO1) protects cells from oxidative damage. NQO1 has been reported to be upregulated in numerous solid tumors, suggesting a role in carcinogenesis and tumor progression. The present study attempted to investigate the clinical prognostic significance of NQO1 overexpression in pancreatic ductal adenocarcinoma (PDAC). A total of 181 tissue specimens were studied, including 126 PDAC and 55 normal pancreas specimens, which were selected for immunohistochemical staining of NQO1 protein. Immunofluorescence staining was additionally performed to identify the subcellular localization of NQO1 protein in pancreatic cancer BxPC-3 cells. The association between NQO1 overexpression and the clinical features of PDAC were evaluated by χ2 and Fishers exact test. Overall survival of PDAC patients was calculated using Kaplan-Meier analysis. Univariate and multivariate analyses were performed using the Cox proportional hazards regression model. The NQO1 protein was mainly located in the cytoplasm and nucleus of BxPC-3 cells. The strongly positive rate of NQO1 expression in PDAC (65.9%, 83/126) was increased compared with that in normal pancreatic tissues (10.9%, 6/55). The positive rate of NQO1 protein was associated with grading, lymph node stage and tumor-node-metastasis (TNM) stage. Additionally, multivariate analysis suggested that NQO1 was a significant independent prognostic factor along with TNM stage in PDAC. In conclusion, high expression of NQO1 appears to be associated with PDAC progression, and may be an independent prognostic biomarker in PDAC.

Target gene screening and evaluation of prognostic values in non-small cell lung cancers by bioinformatics analysis

BACKGROUND Non-small cell lung cancer (NSCLC) is the major leading cause of cancer-related deaths worldwide. This study aims to explore molecular mechanism of NSCLC. METHODS Microarray dataset was obtained from the Gene Expression Omnibus (GEO) database, and analyzed by using GEO2R. Functional and pathway enrichment analysis were performed based on Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) database. Then, STRING, Cytoscape and MCODE were applied to construct the Protein-protein interaction (PPI) network and screen hub genes. Following, overall survival (OS) analysis of hub genes was performed by using the Kaplan-Meier plotter online tool. Moreover, miRecords was also applied to predict the targets of the differentially expressed microRNAs (DEMs). RESULTS A total of 228 DEGs were identified, and they were mainly enriched in the terms of cell adhesion molecules, leukocyte transendothelial migration and ECM-receptor interaction. A PPI network was constructed, and 16 hub genes were identified, including TEK, ANGPT1, MMP9, VWF, CDH5, EDN1, ESAM, CCNE1, CDC45, PRC1, CCNB2, AURKA, MELK, CDC20, TOP2A and PTTG1. Among the genes, expressions of 14 hub genes were associated with prognosis of NSCLC patients. Additionally, a total of 11 DEMs were also identified. CONCLUSION Our results provide some potential underlying biomarkers for NSCLC. Further studies are required to elucidate the pathogenesis of NSCLC.

Mortalin overexpression predicts poor prognosis in early stage of non–small cell lung cancer

Mortalin is a member of the heat shock protein 70 family, which is involved in multiple cellular processes and may play key roles in promoting carcinogenesis. This study attempted to identify the clinical consequences of Mortalin overexpression and its roles in the prognostic evaluation of non–small cell lung cancer. A total of 120 non–small cell lung cancer samples paired with the adjacent non-tumor tissue samples and 10 normal lung tissues were selected for immunohistochemical staining for Mortalin. The localization of Mortalin was detected in A549 non–small cell lung cancer cells using immunofluorescence staining. The correlations between Mortalin overexpression and the clinical features of non–small cell lung cancers were evaluated using the chi-square test. The survival analysis was calculated via the Kaplan–Meier method and the Cox proportional hazard models. Our studies suggested that Mortalin exhibited a primarily cytoplasmic staining pattern in the non–small cell lung cancers. The rate of strongly positive Mortalin expression was higher in the non–small cell lung cancer samples than in the adjacent non-tumor samples or in normal lung tissues. Mortalin overexpression was significantly correlated with high histological grades, advanced stages, lymph node metastases, and lower disease-free survival and overall survival rates of the patients with non–small cell lung cancer. The survival analysis demonstrated that Mortalin overexpression was a significant independent prognostic factor in non–small cell lung cancer, especially for patients with early stage of non–small cell lung cancer. In conclusion, Mortalin is up-regulated in non–small cell lung cancer, and it may be a potential biomarker of prognostic evaluation and a molecular therapeutic target for patients with early stage of non–small cell lung cancer.

Elevated expression of Tiam1 is associated with poor prognosis and promotes tumor progression in pancreatic cancer

Objective T-cell lymphoma invasion and metastasis inducing factor 1 (Tiam1) is known to be involved in tumor progression. However, its molecular roles and mechanism in pancreatic ductal adenocarcinoma (PDAC) remain unclear. The purpose of this study is to determine Tiam1 expression levels and investigate its underlying molecular mechanism in PDAC. Materials and methods Tiam1 protein expression levels in PDAC tissues were examined using immunohistochemistry. Tiam1 expression was confirmed in pancreatic cancer (PC) cells by Western blot and immunofluorescence staining. Tiam1-silenced PC cells were created using short interfering RNA. Subsequently, colony formation, scratch, and migration and invasion assays were carried out to explore the molecular mechanisms of Tiam1 in PC cells. Results The results indicated that Tiam1 expression was significantly higher in PDAC tissues than in paired non-tumor tissues, and overexpression of Tiam1 was significantly correlated with histological grade (P=0.040) and lymph node metastasis (P=0.031) in PDAC. The PDAC patients with high Tiam1 expression had significantly lower 5-year overall survival than patients with low Tiam1 expression. More importantly, univariate and multivariate analysis suggested that Tiam1 expression, along with lymph node metastasis, is a significant independent prognostic factor for patients with PDAC. Furthermore, we also demonstrated that the downregulation of Tiam1 was associated with decreased cell proliferation and reduced migratory and invasive capability. Conclusion High expression of Tiam1 plays a significant role in the progression of PDAC and may be a potential biomarker of poor prognosis as well as a therapeutic target.

Upregulation of Tiam1 contributes to cervical cancer disease progression and indicates poor survival outcome

T lymphoma invasion and metastasis 1 (Tiam1), a guanine nucleotide exchange factor, is involved in the tumorigenesis of a number of malignancies. This study was aimed to explore the role of Tiam1 in cervical cancer progression, and evaluate the prognostic values. Tiam1 protein expression levels were detected by immunohistochemical (IHC) staining in 174 cervical cancer tissues, 92 of CINs (cervical intraepithelial neoplasia) and 32 of normal cervical epithelia tissues. Clinicopathological parameters and overall survival data were collected and compared between different Tiam1 statuses. The role of Tiam1 in cervical cancer proliferation, migration and angiogenesis were detected using si-RNA (small interfering RNA) transfection. In results, Tiam1 protein showed a cytoplasmic and nuclear staining pattern in cervical cancer tissues. The strongly positive expression of Tiam1 protein was observed in 51.72% (90/174) of cervical cancers, which was significantly higher than in CINs and normal cervical epithelia tissues (9.38%, 3/32). High Tiam1 protein expression was closely associated with advanced clinical stage, differentiation, lymph node (LN) metastasis, HPV infection and lower overall survival (OS) rates in cervical cancer. Multivariate analysis indicated that Tiam1 was an independent prognostic factor, along with clinical stage, in patients with cervical cancer. Additionally, Tiam1 depletion by RNAi in cervical cancer cells significantly decreased cell proliferation, migration and angiogenesis. In conclusion, our study demonstrated that upregulation of Tiam1 contributes to cervical cancer disease progression and indicates poor survival outcome.