An immunohistological study of epidermal growth factor receptor and neu receptor and neu receptor expression in proliferative glomerulonephritis

Cetuximab-induced nephrotic syndrome in a case of metastatic rectal cancer

Proteinuria is common adverse effect that occurs after the use of bevacizumab, but it occurs rarely during administration of cetuximab. We report the first case of nephrotic syndrome induced by cetuximab after completing mFOLFOX6 with bevacizumab followed by sLV5FU2 with bevacizumab for metastatic rectal cancer. Prior to the administration of cetuximab, the patient had never presented proteinuria. After the completion of the loading (400 mg/m(2)) and two subsequent maintenance (250 mg/m(2)) infusions of cetuximab, edema of the lower extremities occurred concomitantly with facial acneiform rash. Based on the laboratory data, diagnosis of nephrotic syndrome was made and secondary diseases of nephrotic syndrome were excluded. Oral administration of prednisolone (0.6 mg/kg/day) was initiated, resulting in no response. The trigger of nephrotic syndrome other than cetuximab was not suggested and attention on occurrence of proteinuria must be devoted to this medicine.

Identification of epidermal growth factor receptor (EGFR) exon 20 single nucleotide polymorphism in Chinese squamous cell carcinoma of head and neck (SCCHN)

CONCLUSION

The 78th single nucleotide polymorphism (SNP) in exon 20 of epidermal growth factor receptor (EGFR) might be a predictor of the clinical course of squamous cell carcinoma of the head and neck (SCCHN), and genetic predisposition could influence the progression of SCCHN in Chinese subjects.

OBJECTIVE

To analyze the clinical significance of EGFR SNP in Chinese SCCHN patients.

MATERIALS AND METHODS

Direct sequencing of exons 18-21 was used to analyze somatic mutations of EGFR. Reverse transcriptase polymerase chain reaction (RT-PCR) was used to evaluate the expression level of EGFR. The chi-square test and Kaplan-Meier method were the main statistical methods used to analyze the correlation of the investigated variables and prognostic significance.

RESULTS

In analyzing exons 18-21 of EGFR in 96 patients with SCCHN, only one SNP was found in the 78th site of exon 20 and it mostly existed in specimens coming from the hypopharynx. Further statistical analysis showed that among the clinical or histopathologic parameters, the 78th SNP had a close relationship with earlier stage and more localized primary carcinoma, while at present the analysis did not support the proposition that the SNP was an independent prognostic factor.

Differential ConA-enriched urinary proteome in rat experimental glomerular diseases

Glomerular diseases are leading causes of end-stage renal diseases worldwide. They are considered to be consequences of injury primarily to the three types of glomerular cells. Differential diagnosis typically relies on invasive biopsy findings. We expected that injuries of different glomerular cells would cause different changes in urinary proteome. The goal of this study was to identify differential urinary proteins distinguishing between injuries of different glomerular cells before significant histopathologic changes. Adriamycin nephropathy and Thy1.1 glomerulonephritis were employed as models with different primary impaired cells. ConA-enriched urinary glycoproteome on day3 were profiled by gel-free shotgun tandem mass spectrometry, and compared with self-healthy controls to identify differential urinary proteins for each model. By comparing the changes of the differential proteins between these two models, we identified 39 proteins with different directions of changes, which may potentially be useful in differentiation; and 7 proteins with the same direction of changes, which may be potential indicators of early renal damage. These differential proteins were of several origins: plasma proteins, proteins with urine or kidney specificity, proteins without tissue-specificity (mainly inflammatory mediators) etc. Our results may help better understand the effects of injuries of different glomerular cells at the initial stage, and lead to the discovery of novel early diagnostic markers for human focal segmental glomerulosclerosis (FSGS) and mesangioproliferative glomerulonephritis (MsPGN) which have the same primary impaired cells with adriamycin nephropathy and Thy1.1 glomerulonephritis, respectively.

Angiogenesis Inhibitor Therapies: Focus on Kidney Toxicity and Hypertension

Angiogenesis inhibitors that target the epidermal growth factor (EGF) receptor (EGFR) and vascular endothelial growth factor (VEGF) constitute an important addition to the therapeutic armamentarium for the treatment of patients with metastatic disease. However, because the same growth factors are expressed in the kidneys, these treatment molecules have renal side effects. EGFR is expressed mainly in tubules (mainly distal and collecting segments) and mesangial and parietal epithelial cells. EGF is involved in maintaining tubular integrity and is a potent mitogen for cultured mesangial cells. Few cases of acute renal failure have been reported related to EGFR inhibitors. VEGF and VEGF receptors are still highly expressed in the kidney. VEGF is expressed in podocytes in the glomerulus, and VEGF receptors are present on endothelial, mesangial, and peritubular capillary cells. Signaling between endothelial cells and podocytes is essential for the proper development and maintenance of the filtration function of the kidney glomerulus. The most common renal class effects of VEGF antagonists are both manageable; hypertension and proteinuria commonly regressive on drug withdrawal. There was a dose-dependent increase in risk of proteinuria and hypertension in patients with cancer who received targeted therapies. Furthermore, few patients with glomerulonephritis or thrombotic microangiopathy secondary to treatment were reported. Hypertension is believed to be nitric oxide dependent, whereas proteinuria seems to be related to downregulation of podocyte tight junction protein. This article reviews data relating to hypertension and proteinuria associated with the use of these drugs.

Epidermal growth factor receptor expression in human renal allograft biopsies: an immunohistochemical study

OBJECTIVE

Epidermal growth factor receptor (EGFR) expression has been implicated in the progression of many tumors related to cell proliferation, differentiation, invasion and inhibition of apoptosis, and EGFR-targeted therapy options are under development. EGFR expression has been identified in normal and diseased native kidneys. However, its expression in renal allografts and its relation to rejection remains unclear. We aimed to investigate EGFR expression in renal allograft biopsies.

MATERIAL AND METHODS

Sections from 52 renal allograft and 11 implantation biopsies were stained by EGFR antibody with streptavidin-biotin-immunoperoxidase method. Immunostaining of EGFR in renal tubules was scored semiquantitatively and the percentage of glomeruli expressing EGFR was determined. The results were correlated with Banff scores and serum creatinine values.

RESULTS

Tubular EGFR expression was observed in 81.8% of implantation and 92.3% of allograft biopsies. Glomerular EGFR expression was identified in 18.2% of implantation and in 26.9% of allograft biopsies. The mean percentage (%) of glomeruli-expressing EGFR was 3.73+/-0.84 for implantation biopsies and 7.9+/-0.17 for allograft biopsies (p = 0.53, Mann Whitney U test). For implantation biopsies, tubular EGFR expression scores were 1.90+/-2.11 and for allograft biopsies, 2.89+/-2.01 (p = 0.08, Mann Whitney U test). Tubular EGFR expression was moderately correlated with interstitial fibrosis and tubular atrophy for allograft biopsies (p = 0.04, r = 0.3 and p = 0.04, r = 0.3, respectively, Spearman's rank correlation).

CONCLUSIONS

These findings suggest a possible role of EGFR expression in renal scarring in the course of chronic allograft nephropathy, probably involved in a complex pathway.

Prognostic significance of EGF receptor expression in early glottic cancer

OBJECTIVE

A positive relationship between epidermal growth factor receptor (EGFR) expression and radioresistance has been shown both in vitro and in vivo. In a group of 31 patients with early glottic cancer treated with definitive radiotherapy, the relationship of EGFR expression with patient and tumor related parameters were analyzed and the prognostic effect of EGFR expression on local control (LC) was assessed.

MATERIAL AND METHOD

Between 1991 and 2001, 114 patients with early glottic (Tis-T2N0M0) squamous cell carcinoma were treated with radiotherapy at our institution. Among these, 31 patients whose pretreatment pathology specimens were available for immunohistochemical analysis formed the study population. Median age was 64 (46-77). Anterior commissure involvement was evident in 12 (38.7%) patients. Distribution according to T stage was as follows: Tis 6 (19.3%), T1 22 (71%), and T2 3 (9.7%). Histopathological grades of the 25 T1-2 tumors were 10/25 (40%) grade 1, 9/25 (36%) grade 2 and 6/25 (24%) grade 3. Our radiotherapy regimen was 66-70 Gy in 33-35 fractions over 6.5-7 weeks. The median follow-up period was 45 months (range, 5-116). Following immunohistochemical staining, quantitative immunohistochemistry (IHC) was performed by image analysis software and stained tumoral area percentage (STAP) was identified. The cut-off value was < or =5% versus >5%. The relationship of EGFR expression with patient (age) and tumor related (T stage, histopathological grade, and anterior commissure involvement) parameters was evaluated using chi-square test. Prognostic significance of EGFR expression, age, T stage, histopathological grade, and anterior commissure involvement on LC was assessed using log-rank test.

RESULTS

No difference was found in EGFR content distribution in relation to age, T stage, histopathological grade, and anterior commissure involvement. In the univariate analysis including age (< or =60 versus >60), T stage (Tis and T1 versus T2), histopathological grade (grade 1 and 2 versus grade 3), anterior commissure involvement (present versus absent), and EGFR expression (high versus low), only T stage and EGFR expression were found to be significant prognostic factors affecting LC (P = 0.0006 and P = 0.03, respectively).

CONCLUSION

The results of this series support that EGFR expression is an unfavorable prognostic factor in early glottic carcinomas. For this reason EGFR IHC may be considered for selecting patients for more aggressive therapies (radiotherapy with different fractionation schemes or surgery) or enrollment into trials targeting EGFR signaling pathways.

EGF stimulates mesangial cell mitogenesis via PI3-kinase-mediated MAPK-dependent and AKT kinase-independent manner: involvement of c-fos and p27Kip1

Epidermal growth factor (EGF) is a potent mitogen for mesangial cells. The mechanism by which EGF induces DNA synthesis is not precisely understood. We investigated the role of phosphatidylinositol (PI)3-kinase in regulating mitogenesis. EGF increased PI3-kinase activity resulting in stimulation of PDK-1 and Akt kinase activities. Blocking of PI3-kinase activity using LY-294002 or adenoviral expression of PTEN, which dephosphorylates PI3,4,5-tris-phosphate and thus inactivates PI3-kinase signaling, significantly inhibits EGF-induced DNA synthesis. Expression of dominant-negative Akt kinase, however, had no effect on DNA synthesis. But it inhibited EGF-induced phosphorylation of FoxO3a transcription factor, thus demonstrating its functional consequences. These data indicate that EGF increases the DNA synthesis in a PI3-kinase-dependent but Akt-independent manner. In addition to activating PI3-kinase signaling, EGF increased Erk1/2 MAPK activity, leading to transcriptional activation of its nuclear target Elk-1 and resulting in c-fos expression. Inhibition of MAPK activity by MEK inhibitor U-0126 abolished EGF-induced DNA synthesis. Because EGF activates PI3-kinase, which also regulates DNA synthesis, the effect of PI3-kinase on MAPK activity was also examined. Inhibition of PI3-kinase signaling blocked EGF-induced MAPK activity as well as Elk-1-dependent reporter transcription and c-fos gene transcription. To further determine the mechanism of EGF-induced DNA synthesis, we investigated the effect of EGF on the cyclin-dependent kinase inhibitor p27(Kip1). EGF reduced the expression of p27(Kip1). Inhibition of PI3-kinase action or MAPK activity abolished the reduction in p27(Kip1) expression induced by EGF. These data provide the evidence that a linear signal transduction pathway involving PI3-kinase-dependent MAPK regulates EGF-induced DNA synthesis in mesangial cells by regulating c-fos and p27(Kip1) expression.

Regulation of ANP clearance receptors by EGF in mesangial cells from NOD mice

Mesangial cells from nonobese diabetic (NOD) mice (D-NOD) that develop diabetes at 2-4 mo express an increased density of atrial natriuretic peptide (ANP) clearance receptors [natriuretic peptide C receptor (NPR-C)] and produce less GMP in response to ANP than their nondiabetic counterparts (ND-NOD). Our purpose was to investigate how both phenotypic characteristics were regulated. Epidermal growth factor (EGF) and heparin-binding (HB)-EGF, but not platelet-derived growth factor or insulin-like growth factor I, inhibited (125)I-ANP binding to ND-NOD and D-NOD mesangial cells, particularly in the latter. NPR-C density decreased with no change in the apparent dissociation constant, and there was also a decrease in NPR-C mRNA expression. The EGF effect depended on activation of its receptor tyrosine kinase but not on that of protein kinase C, mitogen-activated protein kinases, or phosphoinositide-3 kinase. Activation of activator protein-1 (AP-1) was necessary, as shown by the inhibitory effect of curcumin and the results of the gel-shift assay. The cGMP response to physiological concentrations of ANP was greater in EGF-treated D-NOD cells. These studies suggest that EGF potentiates the ANP glomerular effects in diabetes by inhibition of its degradation by mesangial NPR-C via a mechanism involving AP-1.

Heparin-binding EGF-like growth factor contributes to reduced glomerular filtration rate during glomerulonephritis in rats

Heparin-binding epidermal growth factor-like growth factor (HB-EGF), a member of the epidermal growth factor (EGF) family, is expressed during inflammatory and pathological conditions. We have cloned the rat HB-EGF and followed the expression of HB-EGF in rat kidneys treated with anti- glomerular basement membrane (anti-GBM) antibody (Ab) to induce glomerulonephritis (GN). We observed glomerular HB-EGF mRNA and protein within 30 minutes of Ab administration and showed by in situ hybridization that glomerular HB-EGF mRNA expression was predominantly in mesangial and epithelial cells. Expression of HB-EGF correlated with the onset of decreased renal function in this model. To test the direct effect of HB-EGF on renal function, we infused the renal cortex with active rHB-EGF, prepared from transfected Drosophila melanogaster cells. This treatment induced a significant decrease in single nephron GFR (SNGFR), single nephron plasma flow, and glomerular ultrafiltration coefficient and an increase in the glomerular capillary hydrostatic pressure gradient. In addition, anti-HB-EGF Ab administered just before anti-GBM Ab blocked the fall in SNGFR and GFR at 90 minutes without any change in the glomerular histologic response. These studies suggest that HB-EGF expressed early in the anti-GBM Ab GN model contributes to the observed acute glomerular hemodynamic alterations.

Epidermal growth factor receptor immunoreactivity in gallbladder and extrahepatic biliary tract tumours

Elevated levels of epidermal growth factor receptor (EGFR), a transmembrane protein tyrosine kinase receptor, are found in carcinomas from various sites of the body. We investigated the expression of EGFR in carcinoma of the gallbladder (n = 13), common bile duct (n = 7) and ampulla of Vater (n = 9). Non-malignant conditions investigated include chronic cholecystitis (n = 11), gallbladder dysplasia (n = 3) and adenoma (n = 1), and ampullary carcinoma in situ (CIS) (n = 2). Routine immunohistochemistry was employed using a monoclonal antibody against the EGFR protein. Immunostaining was assessed according to both intensity and extent of staining of cells. There was strong immunoreactivity for all gallbladder carcinoma and adenoma, the majority of common bile duct (n = 6; 86%) and ampullary (n = 6; 67%) carcinoma. In contrast, all cases of gallbladder dysplasia, the majority of cases of chronic cholecystitis (n = 7; 64%) and ampullary CIS (n = 2; 67%) had only weak to moderate immunoreactivity. The pattern of immunoreactivity was one of diffuse cytoplasmic and membranous staining. In conclusion, EGFR expression is increased in both gallbladder, common bile duct and ampullary carcinomas but not in non-malignant conditions of the gallbladder and biliary tract. These findings suggest that EGFR overexpression occurs late in the sequential development of gallbladder and biliary tract cancers.