Fyn kinase is implicated in prostate cancer. We illustrate the role of miR-125a-3p in cellular pathways accounted for motility and migration of prostate cancer cells, probably through its regulation on Fyn expression and Fyn-downstream proteins. Prostate cancer PC3 cells were transiently transfected with empty miR-Vec (control) or with miR-125a-3p. Overexpression of miR-125a-3p reduced migration of PC3 cells and increased apoptosis. Live cell confocal imaging indicated that overexpression of miR-125a-3p reduced the cells' track speed and length and impaired phenotype. Fyn, FAK and paxillin, displayed reduced activity following miR-125a-3p overexpression. Accordingly, actin rearrangement and cells' protrusion formation were impaired. An inverse correlation between miR-125a-3p and Gleason score was observed in human prostate cancer tissues. Our study demonstrated that miR-125a-3p may regulate migration of prostate cancer cells.

Renal cancers account for more than 3% of adult malignancies and cause more than 13,000 deaths per year in the US alone. The four most common types of kidney tumors include the malignant renal cell carcinomas; clear cell, papillary, chromophobe and the benign oncocytoma. These histological subtypes vary in their clinical course and prognosis, and different clinical strategies have been developed for their management. In some kidney tumor cases it can be very difficult for the pathologist to distinguish between tumor types on the basis of morphology and immunohistochemistry (IHC). In this publication we present the development and validation of a microRNA-based assay for classifying primary kidney tumors. The assay, which classifies the four main kidney tumor types, was developed based on the expression of a set of 24 microRNAs. A validation set of 201 independent samples was classified using the assay and analyzed blindly. The assay produced results for 92% of the samples with an accuracy of 95%.

Abstract Background: Renal cancers account for more than 3% of adult malignancies and result in more than 13,000 deaths per year in the US alone. The four most common types of kidney tumors include the malignant renal cell carcinomas: clear cell, papillary and chromophobe, as well as the benign oncocytoma. These histological subtypes vary in their clinical course and their prognosis, and different clinical strategies have been developed for their management. The differential diagnosis between the subtypes of kidney tumors based on morphology alone can be challenging, and is subjected to inter- and intra-observer variability. Even when utilizing immunohistochemistry (IHC) markers, the ability to differentiate between sub-types can be difficult, especially in the setting of uncommon morphology and biopsy sample with small amounts of tumor tissue. We present the development and validation of a microRNA-based test for classifying primary kidney tumors. Methods: 181 Formalin Fixed Paraffin Embedded (FFPE) samples from primary kidney tumors were collected and reviewed by pathologists from different institutes according to morphology and available IHC labeling data. High-quality total RNA, including the well-preserved microRNA fraction, was extracted from the FFPE samples using a proprietary protocol. Expression levels of hundreds of microRNAs were profiled using a custom microarray platform. Technical validation of the array results was performed using qRT-PCR. A diagnostic assay was developed using a K-nearest neighbor algorithm that searches for the 5 samples in the training database (181 samples used for assay development) that are most similar to the tested sample. The result for the tested sample is defined by a majority vote of the pre-determined subtypes of these 5 closest neighbors. A validation set of 201 independent samples was classified using the assay and analyzed blindly. Results: A set of 24 differentially expressed microRNAs were found to separate the four kidney tumor subtypes and were chosen as classifiers in the KNN algorithm. Clinical validation was performed using an independent, blinded sample set. The test was able to produce results for 92% of the validation set of 201 samples with accuracy of 95%. Conclusions: Expression levels of 24 microRNAs measured on a microarray platform were found to accurately differentiate the four main types of primary kidney tumors. These findings were the basis for the development and validation of a standardized diagnostic assay for the classification of renal cell tumors in FFPE samples from resections or biopsies. This assay can serve as a reliable diagnostic tool to aid physicians with the growing unmet need for kidney tumor classification. Citation Format: Robert Wassman, Brianna St. Cyr, Eddie Fridman, Iris Barshack, Yajue Huang, Sofia Zilber, Mats Sanden, Hila Benjamin, Noga Yerushalmi, Yael Spector. Development and validation of a microRNA-based diagnostic assay for the classification of renal cell tumors. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 802. doi:10.1158/1538-7445.AM2013-802

Abstract Background: The SRC-family of kinases (SFKs) has been broadly implicated in the pathogenesis of prostate cancer. Fyn, a member of the SFKs, mediates mitogenic signals and regulates proliferation, adhesion and motility. Cumulative data indicate that Fyn serves as a proto-oncogene and is known to be over-expressed in several types of malignancies. MicroRNAs are noncoding RNAs that are aberrantly expressed in cancer and seem to influence tumor behavior and progression. In a previous study performed in human embryonic kidney (HEK 293T) cells, we have validated the binding specificity of miR-125a-3p and Fyn 3’UTR using Luciferase assay and established the regulation of Fyn expression and signaling by miR-125a-3p. In the current study we aimed to characterize the interplay between miRNA-125a-3p and Fyn in prostate cancer. Methods: Prostate cancer (PC3) cell line, were transiently transfected with empty miR-vec (control) or with miR-125a-3p and their cell cycle and apoptotic rate were measured by fluorescence activated cell sorting (FACS). The migration ability was measured by transwell assay and scratch assay. Proliferation was assessed by MTT assay. Quantitative PCR and western blot analysis were implicated to determine the effect of miR-125a-3p on Fyn expression as well as on the activation state of its downstream effectors/proteins FAK, Akt and paxillin. Extraction of miRNA from formalin fixed paraffin-embedded (FFPE) cancerous and matched adjacent prostate tissues was performed with miRNeasy FFPE Kit on a cohort of 20 human prostate cancer specimens. Results: Overexpression of miR-125a-3p in PC3 cells reduced significantly the expression of Fyn mRNA and protein and led to impaired cell viability to an arrest at the G2/M phase of the cell cycle. Moreover, overexpressing of miR-125a-3p reduced the activity of FAK, Akt and paxillin and the secretion of VEGF to the culture media. In miRNA125a-3p-overexpressing PC3 cells the migration was compromised by 50% and cell viability decreased by 50%. Moreover, we observed an inverse correlation between the expression of miR-125a-3p and the Gleason score of tissue samples obtained from patients diagnosed with prostate cancer, whereas the expression of miR-125a-3p was extremely reduced in Gleason score higher than 8. Conclusions: Our study indicates miR-125a-3p signature in cellular pathways accounted for cell viability and migration of prostate cancer cells. The interplay between miR-125a-3p and Fyn may represent a new plausible therapeutic target in prostate cancer. Citation Format: Lihi Ninio Many, Irit Ben-Aharon, Sofia Zilber, Mattan Levy, Salomon M. Stemmer, Ruth Shalgi. The role of miRNA-125a-Fyn interplay in prostate cancer tumorigenesis. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4168. doi:10.1158/1538-7445.AM2013-4168

Spontaneous regression of renal cell cancer is a rare phenomenon, with an estimated incidence <1%.1 Most cases had been observed after a surgical resection of the primary tumor, but regression can also occur in association with radiofrequency ablation, radiation, or embolization of the primary tumor.1 The site of the regression was most commonly in the lung. Here, we report the a case of spontaneous regression after cessation of treatment with sorafenib that occurred in a patient with papillary renal cell cancer.

The detection of breast carcinoma cells in effusions is associated with rapidly fatal outcome, but these cells are poorly characterized at the molecular level. This study compared the gene array signatures of breast carcinoma cells in primary carcinomas and effusions. The genetic signature of 10 primary tumors and 10 effusions was analyzed using the Array-Ready Oligo set for the Human Genome platform. Results for selected genes were validated using PCR, Western blotting, and immunohistochemistry. Array analysis identified 255 significantly downregulated and 96 upregulated genes in the effusion samples. The majority of differentially expressed genes were part of pathways involved in focal adhesion, extracellular matrix-cell interaction, and the regulation of the actin cytoskeleton. Genes that were upregulated in effusions included KRT8, BCAR1, CLDN4, VIL2, while DCN, CLDN19, ITGA7, and ITGA5 were downregulated at this anatomic site. PCR, Western blotting, and immunohistochemistry confirmed the array findings for BCAR1, CLDN4, VIL2, and DCN. Our data show that breast carcinoma cells in primary carcinomas and effusions have different gene expression signatures, and differentially express a large number of molecules related to adhesion, motility, and metastasis. These differences may have a critical role in designing therapy and in prognostication for patients with metastatic disease localized to the serosal cavities.