Background: The role of angiogenesis in the pathogenesis of renal cell carcinoma is well recognized, however, the influence of tumor cells in this activity has not yet been fully clarified. The aim of this study was to analyze the expression of hypoxia inducible factor-1α (HIF-1α), a regulatory factor of angiogenic switch, in comparison to vascular endothelial growth factor A and C (VEGF-A and VEGF-C), recognized to be involved in blood and lymph vessel neoangiogenesis, with potential association in the prognosis of patients with renal cell carcinoma. Methods: Ninety-four patients with diagnosis of clear cell renal cell carcinomas (CCRCC), all clinicopathological characteristics and overall survival were unrolled in this study. Immunohistochemicaly VEGF-A, VEGF-C, HIF-1α and Ki67 were detected on tumor cells and the staining was performed on tissue microarrays (TMA). The staining was evaluated as a percentage of cytoplasmic or nuclear positive tumor cells. Results: Variable expression of all three proteins was confirmed. Both angiogenic factors demonstrated perimembranous or diffuse cytoplasmic staining, with diffuse pattern positively associated (p < 0.001). Nuclear HIF-1α expression (nHIF-1α) showed inverse correlation with diffuse cytoplasmic VEGF-A (p = 0.002) and VEGF-C (p = 0.053), while cytoplasmic HIF-1α expression (cHIF-1α) showed positive correlation with diffuse staining of both angiogenic factors (p < 0.001; p < 0.001, respectively). In comparison to clinicopathological characteristics, a higher nuclear grade (p = 0.006; p < 0.001, respectively), larger tumor size (p = 0.009; p = 0.015, respectively), higher stage (p = 0.023; p = 0.027, respectively) and shorter survival (p = 0.018; p = 0.024, respectively) were associated with overexpression of cHIF-1α and diffuse cytoplasmic VEGF-A expression. In contrary, overexpression of nHIF-1α was associated with better diagnostic parameters i.e. lower nuclear grade (p = 0.006), smaller tumor size (p = 0.057), and longer survival (p = 0.005). Conclusion: Overexpression of VEGF-A and cHIF-1α in tumor cells highlights a more aggressive subtype of CCRCC that might have some clinical implications. The significance of nHIF-1α expression associated with better differentiated tumors should be further elucidated.
1 August 2006 in Pathology - Research and Practice
Background: The role of epidermal growth factor (EGF) and its receptor (EGFR) in the pathogenesis and progression of various malignant tumors has long been known, but there is still disagreement concerning prognostic significance of EGFR expression in clear cell renal cell carcinoma (CCRCC). The present study was designed to analyze more objectively the protein EGFR expression in CCRCC and to compare its value with EGFR gene copy number changes and clinicopathologic characteristics including patient survival. Methods: The protein EGFR expression was analyzed immunohistochemically on 94 CCRCC, and gene copy number alterations of EGFR by FISH analysis on 41 CCRCC selected according to distinct membrane EGFR staining. Results: Membrane EGFR expression in tumor cells was heterogeneous with respect to the proportion of positive cells and staining intensity. FISH analysis did not reveal EGFR gene amplification, while polysomy of chromosome 7 found in 41% was associated with higher EGFR membrane expression. Moreover, EGFR overexpression was associated with a higher nuclear grade, larger tumor size and shorter patient's survival, while there was no connection with pathological stage. Conclusion: In conclusion, the protein expression of EGFR had an impact on prognosis in patients with CCRCC, while an increased copy number of chromosome 7 could be the possible reason for EGFR protein overexpression in the absence of gene amplification.
1 February 2011 in Pathology - Research and Practice
Whole blood has been found to be a reliable matrix for the detection and quantitation of cytomegalovirus (CMV) DNA. In this study, the performance of the artus CMV LightCycler (LC) PCR kit in conjunction with automated sample preparation on a BioRobot EZ1 workstation was evaluated. The accuracy, linearity, analytical sensitivity, and inter- and intra-assay variations were determined. A total of 102 clinical EDTA whole-blood samples were investigated, and results were compared with those obtained with the in vitro diagnostics (IVD)/Conformité Européene (CE)-labeled CMV HHV6,7,8 R-gene quantification kit. When the accuracy of the new kit was tested, seven of eight results were found to be within ±0.5 log 10 unit of the expected panel results. Determination of linearity resulted in a quasilinear curve over more than 5 log units. The lower limit of detection of the assay was determined to be 139 copies/ml in EDTA whole blood. The interassay variation ranged from 15 to 58%, and the intra-assay variation ranged from 7 to 35%. When clinical samples were tested and the results were compared with those of the routinely used IVD/CE-labeled assay, 53 samples tested positive and 13 samples tested negative by both of the assays. One sample was found to be positive with the artus CMV LC PCR kit only, and 35 samples tested positive with the routinely used assay only. The majority of discrepant results were found with low-titer samples. In conclusion, use of the artus CMV LC PCR kit in conjunction with automated sample preparation on the BioRobot EZ1 workstation may be suitable for the detection and quantitation of CMV DNA in EDTA whole blood in the routine low-throughput laboratory; however, low-positive results may be missed by this assay.