Alpha adrenergic receptors in renal pelvis and calyces: can rat models be used?

We aimed, in this study, to determine the distribution of α-1 AR subtypes in rat and human pelvis and calyces, and to evaluate, by comparing these two species, the possibility of rats to be used as models for humans. Twenty patients with renal carcinoma were included into the study. The patients underwent radical nephrectomy for renal cell carcinoma (RCC). After nephrectomy, specimens were evaluated and excisional biopsies from healthy pelvis and calyces tissues were performed. When pathology confirmed the non-invasion of RCC, specimen was included into the study. A total of 7 adult Wistar Albino (250-300 g) female rats were used in this study. Specimens included renal pelvis and calyces. All specimens were evaluated under light microscope histopathologically. The concentrations of the receptor densities did not differ between the two groups. With the demonstration of the α receptors in rat kidneys and calyces, many receptor-based studies concerning both humans and rats can take place. Novel medication targeting these subtypes -in this matter α1A and α1D for renal pelvis and calyces- may be helpful for expulsive therapy and/or pain relief. With the demonstration of similar receptor densities between human and rat tissues, rat model may be useful for α-receptor trials for renal pelvis and calyces.

Differencial proteome of clear-cell renal cell carcinoma (ccRCC) tissues

Purpose We attempted to detect, for the first time in a Brazilian cohort, differences in protein expression between clear-cell renal cell carcinoma (ccRCC) and their normal adjacent tissues, aiming to identify biomarkers and/or therapeutic target candidates for this disease. Material and Methods Twenty-four ccRCC and adjacent normal tissues were collected after surgery and their protein extracts were quantified, pooled and separated by two-dimensional polyacrylamide gel electrophoresis (2DE), followed by statistical analysis of the stained gels. Spots of interest were excised from the gels, digested with trypsin and identified by MALDI-TOF-TOF mass spectrometry. Results Twenty-six differential spots were detected between the two classes of tissues, among which twenty were identified by mass spectrometry and sixteen were found to be non-redundant. Eleven proteins were either underexpressed or undetected in the ccRCC extracts, such as prohibitin and peroxiredoxin-3, whereas five were found to be overexpressed or exclusively detected in the ccRCC extract, including αβ crystalin and heat shock protein 27. CONCLUSIONS Several proteins were detected at differential levels when compared to normal adjacent tissues, and, moreover, many have been previously described by their relationship with RCC. Therefore, this work corroborates previous reports on the search for biomarkers for ccRCC, as well as it points out new candidates that may be validated in future studies. .

Immunohistochemical expression of CD44s in renal cell carcinoma lacks independent prognostic significance

PURPOSE: To analyze the immunohistochemical expression of the standard isoform of CD44 (CD44s) adhesion molecule in clear cell renal cell carcinoma (CCRCC) and its impact on clinical outcomes. MATERIALS AND METHODS: Ninety-nine consecutive patients treated surgically for RCC between 1992 and 2009 were selected. A single pathologist reviewed all cases to effect a uniform reclassification and determine the most representative tumor areas for construction of a tissue microarray. The same pathologist, who was blinded to the outcome of the cases, semi-quantitatively scored the staining intensity of CD44s in all specimens. The counting was done using the H-Score algorithm. RESULTS: Of the 99 immunostained RCC specimens, 57(57.7%) showed low expression, and 42(42.4%) showed high expression levels of CD44s. The expression of CD44s was directly associated with tumor size (p = 0.03), clinical stage (p = 0.02) and Fuhrman grade (p = 0.02). Disease specific survival (DSS) rates for patients whose specimens expressed low and high levels of CD44s was 88.1% and 67.5%, respectively (p = 0.009). Progression free survival (PFS) rates in patients with low and high expression of CD44s were 78.8% and 61.7%, respectively (p = 0.05). Classical features such as the presence of metastasis and clinical stage remained isolated predictors of survival. CONCLUSIONS: Immunohistochemical expression of CD44s was associated with important clinical variables such as stage and Fuhrman grade. However, it was not an independent predictor of survival. Therefore, we believe it has a limited role as a prognostic marker in patients with CCRCC.

Metastatic renal cell carcinoma in a meningioma: a case report

Tumor-to-tumor metastasis is rare. We report a case of metastatic renal cell carcinoma in meningioma. A 67-year-old woman presented a two-week history of motor dysphagia and decreased short-term memory. She had undergone a left radical nephrectomy for a renal cell carcinoma 7 years ago, and had not received any adjuvant therapy. MRI disclosed a 3.0 x 3.0 x 3.0-cm sized round tentorial-based extraaxial mass with peritumoral edema in the left posterior temporal lobe. During operation, the tumor was found to be an encapsulated mass firmly attached to the tentorium. Histologically, the tumor was a meningotheliomatous meningioma extensively infiltrated by metastatic renal cell carcinoma, accompanying widespread coagulative necrosis. Immunohistochemical staining for cytokeratin revealed strong positivity only in the renal cell carcinoma component. The patient's postoperative course was uneventful. Post-operative radiation therapy was applied to the whole brain. Three months after operation, the patient developed right hemiparesis and dysphagia. Brain MRI at that time did not reveal recurrence or any other causative lesions, although the whole body scan disclosed uptake at the second lumbar vertebra and rib. The patient refused further treatment.