19 research outputs found

    Nuclear Localization of CXCR4 Determines Prognosis for Colorectal Cancer Patients

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    Chemokines and their receptors are implicated in formation of colorectal cancer metastases. Especially CXCR4 is an important factor, determining migration, invasiveness, metastasis and proliferation of colorectal cancer cells. Object of this study was to determine expression of CXCR4 in tumor tissue of colorectal cancer patients and associate CXCR4 expression levels to clinicopathological parameters. Levels of CXCR4 expression of a random cohort of patients, who underwent primary curative resection of a colorectal carcinoma, were retrospectively determined by quantitative real-time RT-PCR and semi-quantitative analyses of immunohistochemical stained paraffin sections. Expression levels were associated to clinicopathological parameters. Using RT-PCR we found that a high expression of CXCR4 in the primary tumor was an independent prognostic factor for a poor disease free survival (p = 0.03, HR: 2.0, CI = 1.1–3.7). Immunohistochemical staining showed that nuclear distribution of CXCR4 in the tumor cells was inversely associated with disease free and overall survival (p = 0.04, HR: 2.6, CI = 1.0–6.2), while expression in the cytoplasm was not associated with prognosis. In conclusion, our study showed that a high expression of nuclear localized CXCR4 in tumor cells is an independent predictor for poor survival for colorectal cancer patients

    Clinical impact of HLA class I expression in rectal cancer

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    Contains fulltext : 69499.pdf (publisher's version ) (Open Access)PURPOSE: To determine the clinical impact of human leukocyte antigen (HLA) class I expression in irradiated and non-irradiated rectal carcinomas. EXPERIMENTAL DESIGN: Tumor samples in tissue micro array format were collected from 1,135 patients. HLA class I expression was assessed after immunohistochemical staining with two antibodies (HCA2 and HC10). RESULTS: Tumors were split into two groups: (1) tumors with >50% of tumor cells expressing HLA class I (high) and (2) tumors with < or =50% of tumor cells expressing HLA class I (low). No difference in distribution or prognosis of HLA class I expression was found between irradiated and non-irradiated patients. Patients with low expression of HLA class I (15% of all patients) showed an independent significantly worse prognosis with regard to overall survival and disease-free survival. HLA class I expression had no effect on cancer-specific survival or recurrence-free survival. CONCLUSIONS: Down-regulation of HLA class I in rectal cancer is associated with poor prognosis. In contrast to our results, previous reports on HLA class I expression in colorectal cancer described a large population of patients with HLA class I negative tumors, having a good prognosis. This difference might be explained by the fact that a large proportion of HLA negative colon tumors are microsatellite instable (MSI). MSI tumors are associated with a better prognosis than microsatellite stable (MSS). As rectal tumors are mainly MSS, our results suggest that it is both, oncogenic pathway and HLA class I expression, that dictates patient's prognosis in colorectal cancer. Therefore, to prevent confounding in future prognostic analysis on the impact of HLA expression in colorectal tumors, separate analysis of MSI and MSS tumors should be performed

    Sialyl Lewis X Expression and Lymphatic Microvessel Density in Primary Tumors of Node-negative Colorectal Cancer Patients Predict Disease Recurrence

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    Up to 30% of curatively resected colorectal cancer patients with tumor-negative lymph nodes, show disease recurrence. We assessed whether these high-risk patients can be identified by examining primary tumors for the following blood and lymphatic vasculature markers: A) sialyl Lewis X (sLeX), vascular endothelial growth factor (VEGF)-C and VEGF-D expression; B) blood and lymphatic microvessel density (BMVD/LMVD); and C) the presence of blood and lymphatic vessel invasion. Thirty-six cases (disease recurrence within 5 years) and 72 controls (no disease recurrence for at least 5 years) were selected in a case-control design. Tumor sections were stained by antibodies CSLEX1 (sLeX), anti-VEGF-C, anti-VEGF-D, anti-CD31 (BMVD) or D2–40 (LMVD) to determine the parameters as mentioned above. A multivariate analysis showed sLeX expression and high LMVD (odds ratio 5.1, 95% confidence interval 1.3–20.0 and odds ratio 3.1, 95% confidence interval 1.0–10.0, respectively) to be independent factors predicting disease recurrence. Expression of sLeX correlated with liver metastases (P = 0.015). A high LMVD was related to regional intra-abdominal or intrapelvic metastases in lymph nodes and distant metastases other than in the liver and lungs such as peritoneum, bones, brain and adrenal glands (P = 0.004). A high BMVD in the invasive front correlated with lung metastases (P = 0.018). We show that high-risk node-negative colorectal cancer patients can be identified by primary tumor assessment for sLeX expression and LMVD. Our results are consistent with the notion that both lymphatic and hematogenous metastasis play a role in colorectal cancer

    A Reactive Platform Approach for the Rapid Synthesis and Discovery of High χ/Low <i>N</i> Block Polymers

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    We report a reactive polymer platform for the rapid discovery of strongly segregated diblock polymers that microphase separate into well-defined morphologies with sub-5 nm features. Our strategy employs reactive poly­(styrene-<i>block</i>-2-vinyl-4,4-dimethylazlactone) (SV) polymers with low degrees of polymerization (<i>N</i>), in which the V blocks undergo selective and quantitative reactions with functional primary amines, to identify new poly­(acrylamides) that are highly immiscible with poly­(styrene) and induce block polymer self-assembly. Using a combination of optical birefringence and small-angle X-ray scattering (SAXS), we characterize a library of 17 block polymers produced by amine functionalization of four parent SV diblocks synthesized by sequential RAFT polymerizations. We demonstrate that V block functionalization with hydroxy- and methoxy-functional amines yields diblocks that order into lamellar mesophases with half-pitches as small as 3.8 nm. Thus, this azlactone-based reactive molecular platform enables combinatorial generation of polymer libraries with diverse side chain structures that may be rapidly screened to identify new high χ/low <i>N</i> systems for self-assembly at ever decreasing length scales

    Post-Fabrication Placement of Arbitrary Chemical Functionality on Microphase-Separated Thin Films of Amine-Reactive Block Copolymers

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    We report an approach to the post-fabrication placement of chemical functionality on microphase-separated thin films of a reactive block copolymer. Our approach makes use of an azlactone-containing block copolymer that microphase separates into domains of perpendicularly-oriented lamellae. These thin films present nanoscale patterns of amine-reactive groups (reactive stripes) that serve as handles for the immobilization of primary amine-containing functionality. We demonstrate that arbitrary chemical functionality can be installed by treatment with aqueous solutions under mild conditions that do not perturb underlying microphase-separated patterns dictated by the structure of the reactive block copolymer. This post-fabrication approach provides a basis for the development of modular approaches to the design of microphase-separated block copolymer thin films and access to coatings with patterned chemical domains and surface properties that would be difficult to prepare by the self-assembly and processing of functionally complex block copolymers
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