Correlation between BRCA1 and TopBP1 protein expression and clinical outcome of non-small cell lung cancer treated with platinum-based chemotherapy.

PURPOSE: To investigate the correlation between protein expression of breast cancer susceptibility gene 1 (BRCA1) and topoisomerase IIß-binding protein 1 (TopBP1) and clinical outcome of non-small cell lung cancer treated with platinum-based chemotherapy. METHODS: Immunohistochemical staining was conducted to detect the protein expression of BRCA1 and TopBP1 in 101 cases of NSCLC and to correlate these with clinical features, disease progression, and patient survival. Chi-square test (χ (2)-test) was used to evaluate categorical variables. Spearman's rank order correlation was used to analyze continuous variables. Overall survival rate of NSCLC patients was analyzed by Kaplan-Meier survival curve and log-rank test. Relevant factors affecting the survival of patients with advanced NSCLC were analyzed by COX proportional hazards regression model. RESULTS: A total of 101 NSCLC patients were included in the present study. In tumor tissue specimens, positive expression rates of BRCA1 and TopBP1 proteins were 51.5 and 57.4 %, respectively. A significant correlation between the positive expression of BRCA1 and the positive expression of TopBP1 was observed (P < 0.001, r = 0.326). No significant correlation between BRCA1/TopBP1 and age, gender, smoking status, performance status score, pathohistological type, or clinical stage was detected (P > 0.05). During the follow-up period, 65 patients died, and 86 patients showed progression at the end of the study. The survival rate of patients with negative BRCA1 protein expression was higher than that in patients with positive BRCA1 protein expression [median overall survival (OS) 34 vs. 21 months, HR 1.913, 95 % CI 1.161-3.150, P = 0.011]. Similarly, the survival rate of patients with negative TopBP1 expression was higher than that in patients with positive TopBP1 (median OS 36 vs. 23 months, HR 1.931, 95 % CI 1.157-3.224, P = 0.012). No significant correlation between protein expression of BRCA1 or TopBP1 with NSCLC disease progression was observed (P > 0.05). CONCLUSIONS: The present study indicates NSCLC patients with negative BRCA1 and TopBP1 expression showed better prognosis than those with positive protein expression.

Luteolin sensitizes two oxaliplatin-resistant colorectal cancer cell lines to chemotherapeutic drugs via inhibition of the Nrf2 pathway.

Oxaliplatin is a first-line therapy for colorectal cancer, but cancer cell resistance to the drug compromises its efficacy. To explore mechanisms of drug resistance, we treated colorectal cancer cells (HCT116 and SW620) long-term with oxaliplatin and established stable oxaliplatin-resistant lines (HCT116-OX and SW620-OX). Compared with parental cell lines, IC50s for various chemotherapeutic agents (oxaliplatin, cisplatin and doxorubicin) were increased in oxaliplatin-resistant cell lines and this was accompanied by activation of nuclear factor erythroid-2 p45-related factor 2 (Nrf2) and NADPH quinone oxidoreductase 1 (NQO1). Furthermore, luteolin inhibited the Nrf2 pathway in oxaliplatin-resistant cell lines in a dose-dependent manner. Luteolin also inhibited Nrf2 target gene [NQO1, heme oxygenase-1 (HO-1) and GSTα1/2] expression and decreased reduced glutathione in wild type mouse small intestinal cells. There was no apparent effect in Nrf2-/- mice. Luteolin combined with other chemotherapeutics had greater anti-cancer activity in resistant cell lines (combined index values below 1), indicating a synergistic effect. Therefore, adaptive activation of Nrf2 may contribute to the development of acquired drug-resistance and luteolin could restore sensitivity of oxaliplatin-resistant cell lines to chemotherapeutic drugs. Inhibition of the Nrf2 pathway may be the mechanism for this restored therapeutic response.

Integration of the Image-Guided Surgery Toolkit (IGSTK) into the Medical Imaging Interaction Toolkit (MITK).

The development cycle of an image-guided surgery navigation system is too long to meet current clinical needs. This paper presents an integrated system developed by the integration of two open-source software (IGSTK and MITK) to shorten the development cycle of the image-guided surgery navigation system and save human resources simultaneously. An image-guided surgery navigation system was established by connecting the two aforementioned open-source software libraries. It used the Medical Imaging Interaction Toolkit (MITK) as a framework providing image processing tools for the image-guided surgery navigation system of medical imaging software with a high degree of interaction and used the Image-Guided Surgery Toolkit (IGSTK) as a library that provided the basic components of the system for location, tracking, and registration. The electromagnetic tracking device was used to measure the real-time position of surgical tools and fiducials attached to the patient's anatomy. IGSTK was integrated into MITK; at the same time, the compatibility and the stability of this system were emphasized. Experiments showed that an integrated system of the image-guided surgery navigation system could be developed in 2 months. The integration of IGSTK into MITK is feasible. Several techniques for 3D reconstruction, geometric analysis, mesh generation, and surface data analysis for medical image analysis of MITK can connect with the techniques for location, tracking, and registration of IGSTK. This integration of advanced modalities can decrease software development time and emphasize the precision, safety, and robustness of the image-guided surgery navigation system.

Effects of transferred NK4 gene on proliferation, migration, invasion and apoptosis of human prostate cancer DU145 cells.

We investigated the ability of NK4, an antagonist of human hepatocyte growth factor (HGF), to inhibit the influence of HGF on proliferation, migration, invasion and apoptosis of human prostate cancer cells. Expression vector pBudCE4.1-EGFP-NK4 containing NK4 cDNA was used to transfect human prostate cancer DU145 cells, and the effects of the autocrine NK4 on tumor cell proliferation, migration, invasion and apoptosis were assessed in vitro. In vivo, we subcutaneously implanted DU145 cells, mock-transfected clone (DU145/empty vector) cells and NK4-transfected clone (DU145/NK4) cells into nude mice, and then evaluated tumor growth, cell proliferation and cell apoptosis in vivo. We found that DU145/NK4 cells expressed NK4 protein. In the in vitro study, autocrine NK4 attenuated the HGF-induced tumor cell proliferation, migration and invasion, and stimulated apoptosis. Furthermore, autocrine NK4 effectively inhibited the HGF-induced phosphorylation of c-Met, extracellular signal-regulated kinase-1 (ERK1). and protein kinase B 1/2 (Akt1/2). Histological examination revealed that autocrine NK4 inhibited proliferation and accelerated apoptosis of prostate cancer cells. These results show that genetic modification of DU145 cells with NK4 cDNA yields a significant effect on their proliferation, migration, invasion and apoptosis. Molecular targeting of HGF/c-Met by NK4 could be applied as a novel therapeutic approach to prostate cancer.