ABSTRACT
Members of the epidermal growth factor (EGF) family have been suggested as prognostic markers in patients with bladder cancer. Thus far, there has been no consensus on their usefulness. We report an analysis of six ligands and two receptors of which a subset correlate to tumor stage and survival. Biopsies from bladder cancer tumors were obtained from 73 patients followed for a median of 28 months. The mRNA content for six ligands [EGF, transforming growth factor alpha (TGF-alpha), amphiregulin (AR), betacellulin (betaCL), heparin-binding EGF-like growth factor (HB-EGF), epiregulin (EPI)] and two receptors [EGF receptor I Human EGF Receptor (HER1) and 2 (HER2)] was examined by a newly developed quantitative reverse transcription-PCR method. Five ligands and two receptors (HER1 and HER2) were present in median concentrations of (10(-21) mol/microg RNA) 0.39 (AR), 11 (betaCL), 2.4 (EPI), 40 (HB-EGF), 1.4 (TGF-alpha), 75 (HER1), and 39,000 (HER2). EGF was barely detectable. A significantly higher expression of EPI (P < 0.001), HB-EGF (P < 0.001), and TGF-alpha (P < 0.05) were observed in T2-T4 tumors as compared with Ta tumors. Especially the expression of EPI mRNA correlated strongly to survival (P < 0.0005), but increased expression of TGF-alpha (P < 0.005), AR, and HB-EGF (P < 0.02) was also associated with a reduced life span. For the first time, mRNA expression of six ligands and two receptors of the EGF family have been examined in bladder cancer tumors. Our data emphasize that members of the EGF family, especially EPI, may be potential bladder tumor markers.
Subject(s)
Biomarkers, Tumor/biosynthesis , Epidermal Growth Factor/biosynthesis , ErbB Receptors/metabolism , Intercellular Signaling Peptides and Proteins , Urinary Bladder Neoplasms/metabolism , Adult , Aged , Aged, 80 and over , Amphiregulin , Betacellulin , Biomarkers, Tumor/genetics , EGF Family of Proteins , Epidermal Growth Factor/genetics , Epiregulin , ErbB Receptors/biosynthesis , ErbB Receptors/genetics , Female , Glycoproteins/biosynthesis , Glycoproteins/genetics , Growth Substances/biosynthesis , Growth Substances/genetics , Humans , Immunohistochemistry , Ligands , Male , Middle Aged , Prognosis , Prospective Studies , RNA, Messenger/biosynthesis , RNA, Messenger/genetics , Receptor, ErbB-2/biosynthesis , Receptor, ErbB-2/genetics , Transforming Growth Factor alpha/biosynthesis , Transforming Growth Factor alpha/genetics , Urinary Bladder Neoplasms/genetics , Urinary Bladder Neoplasms/pathologyABSTRACT
We analysed the expression of epidermal growth factor receptor (EGFr) and transforming growth factor alpha (TGF-alpha) in human bladder tumours. Tumour biopsies were obtained from 54 patients with primary bladder cancer (18 stage T1 and 36 stage T2-4). The protein and mRNA expression of EGFr and TGF-alpha were quantified by ELISA and competitive RT-PCR, respectively. The EGFr protein level was significantly increased in T2-4 tumours (0.44 x 10(-11); 0.0-27.5 x 10(-11) mol/g) compared with T1 tumours (0.0; 0.0-2.0 x 10(-11) mol/g) (median; range; 2p<0.01). The EGFr protein and mRNA level correlated (Spearman r=0.45, 2p<0.005, n=40). Co-expression of TGF-alpha protein and EGFr protein was significantly associated with muscle invasive tumours (T2-4) (chi-squared=7.9, df=3, p<0.05) and the TGF-alpha protein level correlated significantly with EGFr protein expression (Spearman r=0.56, 2p<0.0001, n=54). While tumour stage correlated with survival, no correlation was observed between survival and the expression of EGFr and/or TGF-alpha. In conclusion, human bladder tumours express both EGFr and TGF-alpha. The expression of EGFr and TGF-alpha are closely correlated, and the expression of EGFr and co-expression of EGFr and TGF-alpha correlate with tumour stage.
Subject(s)
ErbB Receptors/genetics , Gene Expression , Transforming Growth Factor alpha/genetics , Urinary Bladder Neoplasms/metabolism , Enzyme-Linked Immunosorbent Assay , ErbB Receptors/analysis , Humans , Neoplasm Invasiveness , Neoplasm Staging , RNA, Messenger/analysis , Reverse Transcriptase Polymerase Chain Reaction , Survival Rate , Transforming Growth Factor alpha/analysis , Urinary Bladder Neoplasms/mortality , Urinary Bladder Neoplasms/pathologyABSTRACT
The present study focuses on the pathogenesis of increased frequency of large-vessel disease in diabetes. The diabetic arterial wall displays characteristic alterations of the extracellular matrix secreted by arterial smooth-muscle cells. The effects of insulin and growth hormone on the synthesis of sulphate-labelled proteoglycans and heparan sulphate proteoglycan were studied. Proteoglycans and heparan sulphate proteoglycan were obtained from the medium and the cell layer of cultured human arterial smooth-muscle cells grown in 5% human serum. Heparan sulphate proteoglycan was quantified using ethanol precipitation combined with specific enzyme degradation. Addition of insulin (0.01, 0.05 and 0.10 mU/ml) induced a significant accumulation of 35S-labelled proteoglycans in the cell layer (2p < 0.005 and 2p < 0.001). The relative amount of cell-associated heparan sulphate proteoglycan increased during insulin stimulation (2p < 0.05). Growth hormone stimulation (5.0 and 10.0 ng/ml) caused a significant decrease in the ratio between heparan sulphate proteoglycan and proteoglycan in the cell layer (2p < 0.02 and 2p < 0.01), whereas the distribution of proteoglycans between the cell layer and the medium was unaltered.
Subject(s)
Growth Hormone/pharmacology , Insulin/pharmacology , Muscle, Smooth, Vascular/metabolism , Proteoglycans/biosynthesis , Aorta/cytology , Aorta/metabolism , Cells, Cultured , Heparan Sulfate Proteoglycans , Heparitin Sulfate/metabolism , Humans , Muscle, Smooth, Vascular/cytology , Proteoglycans/drug effects , Proteoglycans/metabolismABSTRACT
1. Sulphate labelled proteoglycans (PG) synthesized by cultured human arterial smooth muscle cell have been quantified using an improved method based on a combination of specific enzymes and ethanol precipitation. 2. The present method gives quantitative data of PGs and subclasses allowing batchwise analysis of a large number of samples. 3. Approximately 81% +/- 1.7% (mean +/- SD, n = 6) of total PGs synthesized by human arterial smooth muscle cells accumulated in medium. 4. In cell layer and medium chondroitin sulphate proteoglycan constituted 65.0% +/- 0.3% and 75.8% +/- 0.7% (mean +/- SD, n = 3), respectively of sulphated PGs. 5. Heparan sulphate proteoglycan accounted for 26.8% +/- 0.6% in cell layer and 22.6% +/- 0.5% (mean +/- SD, n = 3) in medium of sulphated PGs.
