Expression of the EphA1 protein is associated with Fuhrman nuclear grade in clear cell renal cell carcinomas

Aberrant expression of receptor tyrosine kinase EphA1 in malignant tissues has been reported. However, the expression profile of EphA1 in renal cell carcinoma (RCC) and its association with clinicopathological parameters remain unknown. The aim of this study was to determine the cancerous value of the EphA1 protein expression in patients with renal cell carcinomas. This study included 144 patients with clear cell RCC (ccRCC), 18 patients with chromophobe RCC and 6 patients with papillary RCC. The EphA1 protein was detected in RCC tissue samples by an immunohistochemical staining with a specific polycolonal antibody. The correlation of the expression of the EphA1 protein with clinicopathological parameters was evaluated. High level of the expression of EphA1 was observed in all normal renal tubes. The EphA1 protein was negatively or weakly expressed in 93 out of 144 ccRCC (64.6%) and positively expressed in 51 out of 144 ccRCC (35.4%). The high level expression of the EphA1 protein was significantly associated with younger patients (P<0.001), sex (P=0.016) and lower nuclear grade (P<0.001). No significant relation between the expression of EphA1 and tumor diameter was found (P=0.316). Positive expression of EphA1 was observed in all samples of chromophobe RCC and papillary RCC. Our data indicated that the EphA1 protein may be a new marker for the prognosis of ccRCC.     

Decreased expression of EphA5 is associated with Fuhrman nuclear grade and pathological tumour stage in ccRCC

The incidence of renal cell carcinoma is increasing all over the world. The molecular mechanisms for tumorigenesis, progression and prognosis are still unknown. The erythropoietin‐producing hepatoma amplified sequence (Eph) receptors have been reported to be expressed aberrantly in many types of human cancers and in particular EphA5 may play a role in certain human cancers. In this study, a set of clear cell renal cell carcinoma (ccRCC) tissues were subjected to immunohistochemistry. The relationship between EphA5 protein expression and clinicopathological parameters was statistically analysed. Our data show that EphA5 protein was negatively (0) or weakly (1+) expressed in 48 of 78 (61.5%), moderately (2+) expressed in 15 of 78 (19.2%) and strongly (3+) expressed in 15 of 78 (19.2%) tumour samples of ccRCC. Decreased expression of EphA5 was detected more often in females than in males (P = 0.017, r_s = ?0.267). Expression of EphA5 was related negatively to Fuhrman grade (P = 0.013, r_s = ?0.279) and pathological tumour stage pT (P = 0.003, r_s = ?0.334). No relation between the expression of EphA5 and age of patients was found (P = 0.107, r_s = 0.184). Fuhrman grade and pT stage are the most important factors used in prognosis of ccRCC. Hence this study may provide a new and useful prognostic marker in the clinical practice of ccRCC.     

Diagnostic utility of S100A1 expression in renal cell neoplasms: an immunohistochemical and quantitative RT-PCR study.

S100A1 is a calcium-binding protein, which has been recently found in renal cell neoplasms. We evaluated the diagnostic utility of immunohistochemical detection of S100A1 in 164 renal cell neoplasms. Forty-one clear cell, 32 papillary, and 51 chromophobe renal cell carcinomas, and 40 oncocytomas, 164 samples of normal renal parenchyma adjacent to the tumors and 13 fetal kidneys were analyzed. The levels of S100A1 mRNA detected by quantitative RT-PCR analysis of frozen tissues from seven clear cell, five papillary, and six chromophobe renal cell carcinomas, four oncocytomas, and nine samples of normal renal tissues adjacent to neoplasms were compared with the immunohistochemical detection of protein expression. Clear cell and papillary renal cell carcinomas showed positive reactions for S100A1 in 30 out of 41 tumors (73%) and in 30 out of 32 (94%) tumors, respectively. Thirty-seven renal oncocytomas out of 40 (93%) were positive for S100A1, whereas 48 of 51 (94%) chromophobe renal cell carcinomas were negative. S100A1 protein was detected in all samples of unaffected and fetal kidneys. S100A1 mRNA was detected by RT-PCR in all normal kidneys and renal cell neoplasms, although at very different levels. Statistical analyses comparing the different expression of S100A1 in clear cell and chromophobe renal cell carcinomas observed by immunohistochemical and RT-PCR methods showed significant values (P<0.001), such as when comparing by both techniques the different levels of S100A1 expression in chromophobe renal cell carcinomas and oncocytomas (P<0.001). Our study shows that S100A1 protein is expressed in oncocytomas, clear cell and papillary renal cell carcinomas but not in chromophobe renal cell carcinomas. Its immunodetection is potentially useful for the differential diagnosis between chromophobe renal cell carcinoma and oncocytoma. Further, S100A1 protein expression is constantly detected in the normal parenchyma of the adult and fetal kidney.     

VEGF/VEGFR2 and PDGF-B/PDGFR-β expression in non-metastatic renal cell carcinoma: a retrospective study in 1,091 consecutive patients

Purpose: We aimed to investigate the correlations between the expression of VEGF, PDGF-B, and their receptors (VEGFR2 and PDGFR-β) with pathologic stage or cell type in non-metastatic renal cell carcinoma. Materials and methods: VEGF, VEGFR2, PDGF-B, and PDGFR-β protein expression were evaluated immunohistochemically in prospectively collected 1,423 tumour samples obtained during radical or partial nephrectomy at a tertiary referral center. Intensity of expression was quantified on a scale of 0 to 3, and was compared among renal cell carcinoma cell types. Results: The study cohort consisted of 1,091 patients, of mean age 54 years, including 968 (88.7%) with clear cell, 82 (7.5%) with papillary, 31 (2.8%) with chromophobe, 4 (0.4%) with unclassified, and 6 (0.5%) with other types of renal cell carcinoma. VEGF expression increased with higher T and N stage and Fuhrman nuclear grade. PDGFR-β expression was highest in clear cell renal cell carcinoma, whereas VEGF and PDGF-B expression were highest in papillary renal cell carcinoma. After adjusting for T stage and Fuhrman nuclear grade using multivariate logistic regression analysis, VEGF (OR = 3.57, P < 0.001), VEGFR2 (OR = 1.82, P = 0.017), and PDGF-B (OR = 2.46, P = 0.019) expression were significantly greater in papillary than in clear cell type. Conclusions: Our results indicate that the cytoplasmic expression of VEGF, VEGFR2, PDGF-B, and PDGFR-β in RCC tumour cells is different in various pathologic stage and cell type. Notably, VEGF and PDGF-B expression are higher in papillary than in clear cell renal cell carcinoma. Further studies using quantitative measurement of proangiogenic factors in tumour cell are needed.     

Expressions of EphA2 and EphrinA-1 in early squamous cell cervical carcinomas and their relation to prognosis

By using immunohistochemistry we investigated the expression of EphA2 and EphrinA-1 in 217 early squamous cell cervical carcinomas and examine their prognostic relevance. For EphA2 expression, 21 tumors (10%) showed negative, 108 (50%) weak positive, 69 (32%) moderate positive and 19 (9%) strong positive, whereas for EphrinA-1 expression, 33 tumors (15%) showed negative, 91 (42%) weak positive, 67 (31%) moderate positive and 26 (12%) strong positive. In univariate analysis high expression (strong staining) of EphrinA-1 was associated with poor disease-free (P = 0.033) and disease-specific (P = 0.039) survival. However, in the multivariate analyses neither EphrinA-1 nor EphA2 was significantly associated to survival. The increased levels of EphA2 and EphrinA-1 in a relative high number of early stage squamous cell carcinomas suggested that these two proteins may play an important role in the development of a subset of early cervical cancers. However, EphA2 and EphrinA-1 were not independently associated with clinical outcome.     

Expression of bcl-2 oncoprotein in renal cell tumours

Expression of bcl-2 is associated with inhibition of apoptosis and extension of cell survival. The importance of apoptosis in relation to the development and progression of renal cell neoplasia remains undefined so far. In order to determine the expression of bcl-2 oncoprotein in normal and neoplastic renal cells, 37 renal tumours were investigated by immunolabelling, including 13 clear cell carcinomas, ten tubulopapillary carcinomas, four chromophobic renal cell carcinomas, and ten oncocytomas. Twenty-six samples of adjacent normal renal tissue served as controls. bcl-2 expression was correlated with cell proliferation activity as estimated by Ki67 antigen expression, and p53 protein expression in the tumour samples. The results demonstrate that in the normal kidney, positive bcl-2 immunostaining was present in glomerular parietal epithelial cells, in distal tubular cells, and in sparse proximal tubule cells. Renal cell tumours showed heterogeneous bcl-2 expression according to the tumour cell type. While the majority of carcinomas of clear cell type were usually negative or contained sparsely distributed positive cells, all tubulopapillary carcinomas were consistently positive for bcl-2. In oncocytomas and chromophobic carcinomas, there was a low percentage of bcl-2 immunoreactive tumour cells; some nuclear bcl-2 positivity was detected in one chromophobic tumour. These findings indicate variable bcl-2 oncoprotein expression in different types of renal cell tumours, with the highest level of expression in tubulopapillary carcinomas. No clear relationship was found between nuclear grade, cell proliferation activity, and level of bcl-2 expression. p53 protein was detected in only one tubulopapillary carcinoma.     

Decreased expression of mucin 18 is associated with unfavorable postoperative prognosis in patients with clear cell renal cell carcinoma

Background: MUC18 is correlated with tumor progression and metastasis in types of malignancy. But the role of MUC18 in clear cell renal cell carcinoma remains unclear. In this study, we aimed to investigate the expression of MUC18 and its correlation with clinical outcomes in clear cell renal cell carcinoma. Patients and Methods: Immunohistochemical staining was performed in samples from 288 patients with clear cell renal cell carcinoma. We used Kaplan-Meier method and Cox proportional hazard models to value the association between MUC18 expression and clinical outcome. Nomogram was constructed to predict overall survival at 5 and 8 years after nephrectomy. Results: MUC18 expression was significantly decreased in tumor compared to non-tumor tissue (P<0.001). Lower MUC18 expression in tumor predicted a shorter survival time (P=0.007). By multivariate cox analysis, MUC18 was defined as an independent prognostic factor (P=0.006). The nomogram performed better in predicting 5- and 8-year overall survival than the TNM stage alone in clear cell renal cell carcinoma. Conclusion: MUC18 is an independent prognostic factor for clear cell renal cell carcinoma and could be incorporated with the other parameters to predict 5- and 8-year overall survival for clear cell renal cell carcinoma patients.     

EphA2 as a new target for breast cancer and its potential clinical application

Purpose: The aim of this research was to study the expression of EphA2 to assess its suitability as a new breast cancer target. Methods: Immunohistochemistry (IHC) was used to detect EphA2 protein expression in pathology tissue samples from 250 cases of breast cancer, and the expression of EphA2 mRNA was detected by in situ hybridization (ISH). Breast cancer cells were isolated and cultured. The expression of EphA2 in the cells was detected by the indirect immunofluorescence assay (IFA), and the expression of EphA2 in breast cancer was analysed. Results: EphA2 protein and mRNA were mainly expressed in tumor cells and vascular endothelial cells. EphA2 protein was expressed in 187 cases, with a positive rate of 74.80%, whereas EphA2 mRNA was expressed in 209 cases, with a positive rate of 83.60%. EphA2 protein and mRNA expression were correlated with lymph node metastasis, clinical stage, and breast cancer histologic grade (P<0.05). In addition, the positive expression rates of EphA2 protein and EphA2 mRNA were correlated (P<0.05). EphA2 was barely expressed in normal breast cells but highly expressed in breast cancer cells. Conclusion: EphA2 is highly expressed in breast cancer tissues and has the potential to be a new breast cancer target, providing a preliminary basis for the development of new targeted drugs for breast cancer and the construction of fluorescent-targeted tracers for fluorescence-guided mastoscopic breast-conserving surgery.     

MET expression in sporadic renal cell carcinomas

Although germline mutations of met proto-oncogene on human chromosome 7q31-34 have been known as useful molecular markers of hereditary papillary renal cell carcinoma (RCC), the expression of MET, a product of met proto-oncogene, has not been fully studied in sporadic RCC, along with its clinical significance. We investigated the expression of MET by immunohistochemistry in 182 cases of renal neoplasm encompassing 145 RCC, 25 urothelial carcinomas of renal pelvis, and 12 oncocytomas. MET was diffusely and strongly expressed in 90% of papillary RCC, all collecting duct carcinomas, and 92% of urothelial carcinomas of renal pelvis. On the contrary, clear cell RCC, chromophobe RCC, and oncocytomas were negative or focally positive for MET expression. In clear cell RCC, MET expression was positively correlated with high nuclear grade, presence of infiltrative growth, tumoral necrosis, papillary architecture, sarcomatoid component, tumoral involvement of the renal pelvis or ureter, involvement of the calyx, and lymphatic invasion. In conclusion, diffuse and strong expression of MET in papillary RCC and collecting duct carcinoma might be helpful in discriminating from the other subtypes of RCC with tubular or papillary growth. In case of MET expression observed in clear cell RCC, it might correlate with those clinicopathological parameters implying aggressive behavior.     

CD10 is expressed in a subset of chromophobe renal cell carcinomas.

CD10 has been considered a useful marker in the diagnosis of renal carcinomas, because of its expression in clear cell and papillary renal cell carcinomas and its absence in chromophobe renal cell carcinomas. On the other hand, chromophobe renal cell carcinoma expresses parvalbumin, which is absent in clear cell and papillary renal cell carcinomas. To further address the relevance of these markers, we studied the expression of CD10 and parvalbumin in 42 samples of chromophobe renal cell carcinoma (seven of which had aggressive features, including invasion beyond the renal capsule, renal vein invasion, metastases, or sarcomatoid transformation), 75 clear cell renal cell carcinomas (eight metastatic) and 51 papillary renal cell carcinomas (two metastatic). CD10 was found in 100% of clear cell renal cell carcinomas, 63% of papillary renal cell carcinomas and in all metastatic cases of both types. At variance with previous studies, we found CD10 expression in from 30 to 90% of the neoplastic cells, in 11 of 42 (26%) chromophobe renal cell carcinomas. The CD10-positive cases included five of the seven (71%) chromophobe renal cell carcinoma with aggressive features. Statistical analysis showed significant association of CD10-positive tumors with clinicopathologic aggressiveness (P=0.003) and mitotic figures (P=0.04). Parvalbumin was strongly expressed in all primary and metastatic chromophobe renal cell carcinomas. Western blot analysis was utilized to confirm the expression of both CD10 and parvalbumin in chromophobe renal cell carcinomas.     

An immunoperoxidase study of renal cell carcinomas: correlation with nuclear grade, cell type, and histologic pattern

We applied a panel of antibodies to formalin-fixed, paraffin-embedded sections of 55 renal cell carcinomas using a three-stage immunoperoxidase technique. The antibody panel included two anti-keratins, AE1 and CAM5.2, anti-epithelial membrane antigen (EMA), anti-vimentin, anti-S100 protein, and the anti-leukocyte marker PD7/26. Forty-eight of 55 renal cell carcinomas expressed keratins. CAM5.2 stained 46 tumors (84%) and AE1 stained 37 neoplasms (67%). AE1 reacted with two CAM5.2-negative tumors. EMA was expressed by 35 carcinomas (64%), including three of the CAM5.2-negative neoplasms. Therefore, using all three antibodies, 50 neoplasms (91%) expressed antigens of epithelial differentiation. Anti-EMA and AE1 were complementary to each other; the combination stained 46 of the carcinomas, comparable with CAM5.2 alone. Vimentin was expressed by 26 tumors (47%), and S100 was expressed by one. PD7/26 did not stain any of the cases. Vimentin expression correlated with nuclear grade; low nuclear grade neoplasms infrequently expressed vimentin, while the converse was true for high nuclear grade tumors. Keratin expression was related to tumor cell type and histologic pattern, as fewer neoplasms of clear cell type and with a solid pattern expressed keratins. In contrast, all papillary and eight of nine (89%) spindled carcinomas expressed keratins.     

Lower and reduced expression of EphA4 is associated with advanced TNM stage,lymph node metastasis,and poor survival in breast carcinoma

The expression of EphA4 has been well documented in the development of nerve and in certain types of human cancer. Few studies of EphA4, however, have focused on breast carcinoma. In this study, a set of breast carcinomas was subjected to immunohistochemical staining. In normal luminal cells, EphA4 was weakly detected in 11 (14.3 %), moderately detected in 15 (19.5 %) and highly detected in 51 out of 77 (66.2 %) samples, while in breast carcinoma cells, EphA4 was weakly detected in 42 (54.5 %), moderately detected in 19 (24.7 %) and highly detected in 16 out of 77 (20.8 %) samples (P < 0.001). The expression of EphA4 protein was significantly reduced in 68.8 % of breast carcinoma samples comparing with normal cells. The expression of EphA4 was significantly associated with tumor grade (P = 0.003), TNM stage (P = 0.034), lymph node metastasis (P = 0.034) and Ki‐67 (P < 0.001). No significant relationship was found between the expression of EphA4 and age, molecular subtypes, and HER2 status. Survival analysis showed that significant association of low expression of EphA4 in tumor cells with short overall survival (P = 0.048) and disease‐free survival (P = 0.051). Our data show that EphA4 was reduced in breast carcinoma, which is associated with high grade, advanced TNM stage, lymph node metastasis, and poor outcome of patients.     

Alpha-methyl CoA racemase expression in renal cell carcinomas

Alpha-methyl CoA racemase (AMACR), a new molecular marker for prostate cancer, has been recently reported to be one of the most highly expressed genes in papillary renal cell carcinomas (RCCs). We tested the diagnostic usefulness of AMACR antibody in a series of 110 renal tumors: 53 papillary RCCs (33 type 1, 20 type 2); 25 conventional RCCs; 6 chromophobe RCCs; 9 oncocytomas; 5 mucinous tubular and spindle tumors; 2 urothelial carcinomas; 7 angiomyolipomas; and 2 Bellini carcinomas. Immunohistochemical staining was performed on formalin-fixed, paraffin-embedded tissue sections, with a primary prediluted rabbit monoclonal anti-AMACR antibody. Both type 1 and type 2 papillary RCCs exhibited cytoplasmic immunoreactivity for AMACR, with diffuse strong granular staining in 96.4% (53/55) of tumors, without correlation with type or nuclear grade. The 5 mucinous, tubular, and spindle cell carcinomas strongly expressed AMACR, and only 5 of 25 clear cell RCCs and 1 of 9 oncocytomas were focally reactive. The remaining 6 chromophobe RCCs, 5 urothelial carcinomas, and Bellini duct carcinomas showed no immunoreactivity for AMACR. Because high expression of AMACR is found in papillary RCCs (type 1 and 2) and in mucinous, tubular, and spindle cell carcinomas of the kidney, immunostaining for AMACR should be used in conjunction with other markers when histological typing of a renal tumor is difficult.     

Carbonic anhydrase IX expression in renal neoplasms: correlation with tumor type and grade

Carbonic anhydrase IX (CAIX), a hypoxia-induced protein, is expressed in some renal tumors. We evaluated its immunohistochemical expression in 317 primary and 42 metastatic renal neoplasms (186 clear cell, 52 papillary, 35 chromophobe, 47 unclassified, and 15 Xp11.2 translocation renal cell carcinomas [RCCs]; 26 oncocytomas; 2 metanephric adenomas; 1 urothelial carcinoma; 1 mixed epithelial and stromal tumor; and 1 angiomyolipoma); 7 neoplasms were unknown as to whether they were primary or metastatic. We also correlated expression with tumor type and grade. Variable staining was seen in clear cell, papillary, unclassified, and Xp11.2 translocation carcinomas. One chromophobe carcinoma had focal expression. No staining was seen with other tumors. An association was found between high expression and clear cell vs non-clear cell carcinomas with all cases (P < .01) and primary (P < .01) cases. An association between CAIX expression and grade (P < .01) in primary clear cell carcinomas was found. CAIX expression is more common in clear cell RCC than other renal tumor types and is associated with grade.     

Expression of vascular endothelial growth factor in renal cell carcinomas

Vascular endothelial growth factor (VEGF) is an angiogenic factor that may be involved in tumor growth and metastasis. Only a few data concerning the role of VEGF in renal cell carcinomas (RCCs) are available, and no studies have yet evaluated its prognostic value. The aim of the present study was to assess VEGF expression in a large series of renal tumors with a long follow-up, correlated with the usual histoprognostic factors and survival. VEGF immunostaining was performed on formalin-fixed, paraffin-embedded archival tissue from 74 renal carcinomas (62 conventional renal cell and 12 papillary carcinomas). Positivity of immunostaining was semi-quantitatively scored by two pathologists. Angiogenesis was evaluated by immunostaining with anti-CD34 antibodies on serial sections. Cytoplasmic VEGF expression was detected in tumor cells in 35% (26/74) of RCCs, including 18 out of the 62 (29%) conventional RCCs and 8 out of the 12 (67%) papillary carcinomas (P=0.02). In the group of conventional RCCs, VEGF expression was positively correlated with both nuclear grade (P=0.05) and size of the tumor (P=0.05). Furthermore, a significant correlation was observed between VEGF expression and microvascular count (P=0.04). Finally, cumulative survival rate was significantly lower in the group of patients with conventional RCCs expressing VEGF (log rank test, P=0.01). In the Cox model, VEGF expression was a significant independent predictor of outcome, as well as stage and nuclear grade. This study suggests that VEGF is involved in angiogenesis in conventional RCCs and appears to be a potential prognostic factor in these tumors. Received: 9 July 1999 / Accepted: 18 October 1999