The purpose of this study was to develop a multitarget, multicolor fluorescence in situ hybridization (FISH) assay for the detection of urothelial carcinoma (UC) in urine specimens. Urinary cells obtained from voided urine specimens of 21 patients with UC and 9 normal donors were analyzed with nine different centromere enumeration probes and a single locus-specific indicator probe to determine an optimal set of FISH probes for UC detection. The four probes with the greatest sensitivity for UC detection were then labeled with a unique fluorophore and combined into a single probe set. The probes with the greatest combined sensitivity for UC detection were CEP3, CEP7, CEP17, and the 9p21 (P16) LSI. This probe set was used to evaluate urine specimens acquired from 179 patients for prospective testing (46 with biopsy-proven UC). FISH slides were evaluated by scanning the slide for cells with nuclear features suggestive of malignancy and assessing the FISH signal pattern of these cells for polysomy (ie, gains of two or more different chromosomes). A receiver operator characteristic curve revealed that a cutoff of 5 cells with polysomy as the positive criterion for cancer resulted in an overall sensitivity of 84.2% for patients with biopsy-proven UC and a specificity of 91.8% among patients with genitourinary disorders but no evidence of UC. This study demonstrates that a multitarget, multicolor FISH assay containing centromeric probes to chromosomes 3, 7, and 17 and a locus-specific probe to band 9p21 has high sensitivity and specificity for the detection of UC in voided urine specimens.
The sensitivity of FISH for the detection of urothelial carcinoma is superior to that of cytology, and the specificity of FISH and cytology for urothelial carcinoma are not significantly different. Further prospective studies are required but FISH has the potential to improve significantly the management of urothelial carcinoma.
Our study reveals that UroVysion is the most sensitive and specific assay among those tested for the detection of urothelial carcinoma. Telomerase testing had good specificity but poor sensitivity. The BTA stat and hemoglobin dipstick tests had good sensitivity but relatively poor specificity. UroVysion is a promising new assay for the detection of urothelial carcinoma in urine specimens. However, further studies are needed to explore the role of the various assays in the treatment of patients with superficial urothelial carcinoma.
Backgroundc-Met is the receptor tyrosine kinase for hepatocyte growth factor (HGF) encoded by the MET proto-oncogene. Aberrant activation of c-Met resulting from MET amplification and c-Met overexpression is associated with poor clinical outcome in multiple malignancies underscoring the importance of c-Met signaling in cancer progression. Several c-Met inhibitors have advanced to the clinic; however, the development of inhibitory c-Met-directed therapeutic antibodies has been hampered by inherent agonistic activity.MethodWe generated and tested a bivalent anti-c-Met monoclonal antibody ABT-700 in vitro for binding potency and antagonistic activity and in vivo for antitumor efficacy in human tumor xenografts. Human cancer cell lines and gastric cancer tissue microarrays were examined for MET amplification by fluorescence in situ hybridization (FISH).ResultsABT-700 exhibits a distinctive ability to block both HGF-independent constitutive c-Met signaling and HGF-dependent activation of c-Met. Cancer cells addicted to the constitutively activated c-Met signaling driven by MET amplification undergo apoptosis upon exposure to ABT-700. ABT-700 induces tumor regression and tumor growth delay in preclinical tumor models of gastric and lung cancers harboring amplified MET. ABT-700 in combination with chemotherapeutics also shows additive antitumor effect. Amplification of MET in human cancer tissues can be identified by FISH.ConclusionsThe preclinical attributes of ABT-700 in blocking c-Met signaling, inducing apoptosis and suppressing tumor growth in cancers with amplified MET provide rationale for examining its potential clinical utility for the treatment of cancers harboring MET amplification.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-016-2138-z) contains supplementary material, which is available to authorized users.
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