dong Wei

Targeted expression of miR-34a using the T-VISA system suppresses breast cancer cell growth and invasion

Recurrence and metastasis result in a poor prognosis for breast cancer patients. Recent studies have demonstrated that microRNAs (miRNAs) play vital roles in the development and metastasis of breast cancer. In this study, we investigated the therapeutic potential of miR-34a in breast cancer. We found that miR-34a is downregulated in breast cancer cell lines and tissues, compared with normal cell lines and the adjacent nontumor tissues, respectively. To explore the therapeutic potential of miR-34a, we designed a targeted miR-34a expression plasmid (T-VISA-miR-34a) using the T-VISA system, and evaluated its antitumor effects, efficacy, mechanism of action, and systemic toxicity. T-VISA-miR-34a induced robust, persistent expression of miR-34a, and dramatically suppressed breast cancer cell growth, migration, and invasion in vitro by downregulating the protein expression levels of the miR-34a target genes E2F3, CD44, and SIRT1. In an orthotopic mouse model of breast cancer, intravenous injection of T-VISA-miR-34a:liposomal complex nanoparticles significantly inhibited tumor growth, prolonged survival, and did not induce systemic toxicity. In conclusion, T-VISA-miR-34a lead to robust, specific overexpression of miR-34a in breast cancer cells and induced potent antitumor effects in vitro and in vivo. T-VISA-miR-34a may provide a potentially useful, specific, and safe-targeted therapeutic approach for breast cancer.

Synergistic effects of curcumin with emodin against the proliferation and invasion of breast cancer cells through upregulation of miR-34a

Curcumin, a biphenyl compound derived from rhizome, is a powerful anti-cancer agent. Emodin is an active component isolated from the root and rhizome of Rheumpalmatum that has been widely used in traditional Chinese medicine for the treatment of various diseases. Currently, there are no studies examining the effect of curcumin in combination with emodin on tumor cell growth. In this study, we report for the first time that combined curcumin and emodin administration synergistically inhibits proliferation (MTT assay), survival (flow cytometry), and invasion (transwell migration assay) of breast cancer cells. Synergism is determined by the Chou–Talalay method. Moreover, we demonstrate that miR-34a is upregulated by curcumin and emodin. This microRNA helps mediate the anti-tumor effects of curcumin and emodin by downregulating Bcl-2 and Bmi-1. Our results not only provide insight into the mechanism of synergy between curcumin and emodin in breast cancer cells, but also suggest a new and potentially useful approach for breast cancer therapy.

A new, preoperative, MRI-based scoring system for diagnosing malignant axillary lymph nodes in women evaluated for breast cancer.

OBJECTIVE Malignant axillary lymph nodes are an important predictor for breast cancer recurrence, but invasive dissection or biopsy is required for the diagnosis. We determined whether and how malignant nodes could be diagnosed preoperatively with magnetic resonance (MR) imaging. MATERIALS AND METHODS We obtained MR images of all women evaluated for breast cancer at the Sun Yat-Sen University Cancer Center in 2010 and correlated the image characteristics of each axillary node with the pathologic diagnosis of the same node. RESULTS We analyzed 251 nodes (117 benign; 134 malignant) from 136 women (mean age, 44 years; range, 20-67). Mean diameter of the nodes was 18 mm (range, 5-58 mm). With pathologic diagnosis as the reference standard, MRI-based interpretations were 66.4% sensitive, 94% specific, and 79% accurate. Diameter, pathologic type, apparent diffusion coefficient value (ADC, b=500 and 800), time-intensity curve (TIC) type of breast tumors correlated with node metastasis; ADC value (b=500 and 800), TIC type, early enhancement rate, long-axis, short-axis, shape, margin and the location of nodes correlated with node metastasis (P<0.001 for all). Tumor immunohistochemistry results for estrogen receptors, progesterone receptors, c-erbB-2, vascular endothelial growth factor, and Ki67 were not. An MRI-based lymph node scoring system based on these correlations had a specificity of 91%, a sensitivity of 93%, and an area under the ROC curve of 0.95 (P<0.001). CONCLUSION Metastatic axillary lymph nodes can be accurately diagnosed by MR in women with early breast cancer preoperatively and non-invasively. The scoring system appears to be superior to current methods.

miR-22 as a prognostic factor targets glucose transporter protein type 1 in breast cancer

It has been reported that miR-22 plays an important role and may be a promising therapeutic target in cancer. In this study, we found that GLUT1 is a direct target of miR-22. The ectopic expression of miR-22 inhibited breast cancer cell proliferation and invasion by targeting GLUT1. A reverse correlation between the expression of miR-22 and GLUT1 was observed in breast cancer tissue samples. Furthermore, miR-22 was significantly correlated with the TNM stage, local relapse, distant metastasis, and survival of breast cancer patients. Our data suggest that miR-22 functions as a tumor suppressor and is a promising prognostic biomarker in breast cancer.

Epidermal growth factor receptor in breast carcinoma: association between gene copy number and mutations

BackgroundThe epidermal growth factor receptor (EGFR) is an available target of effective anti-EGFR therapy for human breast cancer. The aim of this study was to assess the presence of EGFR gene amplification and mutations in breast cancer and to analyze the association between the statuses of these two gene alterations.Materials and methodsEGFR gene amplification and mutations were investigated in formalin-fixed, paraffin-embedded tissues from 139 Chinese female patients with breast cancer by means of fluorescence in-situ hybridization (FISH) and fluorescently labeled real-time quantitative polymerase chain reaction (RT-PCR), respectively.ResultsEGFR gene amplification was observed in 46/139 (33.1%) of cases by FISH. Based on RT-PCR, 2/139 (1.4%) samples had EGFR gene mutations. Overall, only 1 (0.7%) of the cases was identified with both whole gene amplification and mutation, and 92 (66.2%) of cases were negative for both. High gene copy numbers of EGFR had significant correlation with the occurrence of EGFR protein expressions (P = 0.002).ConclusionIn this study, EGFR mutations were presented in only two samples, indicating that EGFR mutations should not be employed in future trials with anti-EGFR therapies for breast cancer. However, EGFR whole gene amplification is frequently observed in patients with breast cancer. It will be of significant interest to investigate whether EGFR gene copy number is a suitable screening test for EGFR-targeted therapy for breast cancer.Virtual SlidesThe virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2521111805741248

Selective COX-2 inhibitor celecoxib combined with EGFR-TKI ZD1839 on non-small cell lung cancer cell lines: in vitro toxicity and mechanism study

Constitutive expression of cyclooxygenase-2 (COX-2) and epidermal growth factor receptor (EGFR) occurs frequently in non-small cell lung cancer (NSCLC). Anticancer research targeting EGFR has got an extensive attention especially in NSCLC and COX-2 inhibitor also shown a certain anticancer activity in recent years. Simultaneously targeting COX-2 and EGFR may be a promising therapeutic way. We carried out the in vitro study using selective COX-2 inhibitor celecoxib combined with EGFR-tyrosine kinase inhibitor (EGFR-TKI) ZD1839 on NSCLC cell lines to investigate the anti proliferation effect and the cell molecular mechanism. MTT growth assay showed the synergistic therapeutic effect of certain concentration of celecoxib combined with ZD1839 and synergistic apoptosis effect was detected by Hoechest33258 fluorescence staining and flow cytometric analysis. In western blot analysis, ZD1839 single agent inhibited the activation of EGFR and downstream cell signal transduction AKT and extrocellular signal-regulated kinase (ERK) pathways, the transcription activity of nuclear factor-kappa B (NF-κB), and the expression of COX-2. Celecoxib single agent could also inhibit AKT and ERK pathway in NSCLC, even the EGFR expression under high concentration treatment. Celecoxib combined with ZD1839 led to stronger inhibition of related cell signal transduction pathways in NSCLC.

Targeted expression of Escherichia coli purine nucleoside phosphorylase and Fludara® for prostate cancer therapy: PNP/Fludara for prostate cancer gene therapy

Previous studies have shown that Herpes Simplex Virus thymidine kinase (HSV‐tk)/ganciclovir (GCV) comprised the most commonly used suicide gene therapy for prostate cancer, with modest results being obtained. However, novel suicide genes, such as Escherichia coli purine nucleoside phosphorylase (PNP), have been utilized to demonstrate more potent tumor killing and an enhanced bystander effect on local, non‐expressing cells compared to HSV‐tk.

mir-101-3p is a key regulator of tumor metabolism in triple negative breast cancer targeting AMPK.

mir-101-3p has been reported to be a tumor suppressor and a promising therapeutic target in cancer. Recently, AMPK dysfunction has been highlighted in cancers, including breast cancer. The aim of this study is to investigate the biological roles of mir-101-3p and AMPK in breast cancer. Our research demonstrated that AMPK was up-regulated in breast cancer tissues and cell lines, especially in triple negative breast cancer (TNBC). High-expression of AMPK correlated with poor outcome in both total breast cancer and TNBC patients. Ectopic expression of AMPK improved glucose uptake, glycolysis, proliferation of TNBC cells in vitro and its tumorigenicity in vivo. AMPK was predicted to be a direct target of mir-101-3p. The luciferase reporter assay was performed to certificate this prediction. The expression of AMPK was suppressed by transfection of mir-101-3p in TNBC cells. Over-expression of mir-101-3p or knock-down of AMPK inhibited glucose metabolism and proliferation of TNBC cells in vitro. Our study provides evidence that mir-101-3p- AMPK axis could be a promising therapeutic target in TNBC targeting tumor metabolism.

Erratum: Targeted expression of Escherichia coli purine nucleoside phosphorylase and Fludara® for prostate cancer therapy

*Correspondence to: X. Xie or W. Wei, State Key Laboratory of Oncology in South China, Department of Breast Oncology, Sun Yat-Sen University Cancer Center, 651 East Dongfeng Road, Guangzhou, 510060, People’s Republic of China or David M Spencer, Department of Pathology and Immunology, Baylor College of Medicine, Houston, Texas 77030, USA. E-mail: xiexm@sysucc.org.cn or weiwd @sysucc.org.cn or dspencer@bcm.edu Both investigators contributed equally and should be considered as senior authors.

Cytokeratin19-2g2, a Novel Fragment of Cytokeratin19 in Serum, Indicating a More Invasive Behavior and Worse Prognosis in Breast Cancer Patients

Background Various studies have been searching for new tumor biomarkers for breast cancer for years. However, so far, few markers have been proved clinically useful except CA153. Based on knowledge that most adenocarcinomas including breast carcinoma expressed Cytokeratin19, the authors studied CK19-2G2,a novel fragment of cytokeratin19 shedding into serum in breast cancer patients. Patients and Methods The serum samples of four hundred and seventeen patients including three hundred and three (fifty-four DCIS and two hundred and forty-nine stage I-III) PBC patients and one hundred and fourteen MBC patients, eighty-one healthy controls and twenty-one breast benign disease patients were provided for measurement of CK19-2G2, CEA and CA153.The correlation between clinicopathological characters, prognosis and CK19-2G2 levels was further studied. Results The serum CK19-2G2 levels in breast cancer patients were significantly higher than that in healthy and benign controls. For breast cancer patients, CK19-2G2 levels in MBC were significantly higher than that in PBC patients. The sensitivities of CK19-2G2 for breast carcinoma are as high as CEA and CA153, and up to 71% in MBC patients. Serum CK19-2G2 levels (≥2 mU/mL) were associated with pathological stages, tumor size (≥2 cm), lymph node involvement, and HER2 status. Multivariate analysis revealed that high serum CK19-2G2 level was an independent factor for relapse (P = 0.029) and death (P = 0.040) in breast cancer patients. Conclusion Serum CK19-2G2 may be an independent indicator for prognosis and a candidate marker for monitoring metastasis in breast cancer.