There is a need to image excised tissues during tumor-resection procedures in order to identify residual tumors at the margins and to guide their complete removal. The imaging of dysregulated cell-surface receptors is a potential means of identifying the presence of diseases with high sensitivity and specificity. However, due to heterogeneities in the expression of protein biomarkers in tumors, molecular-imaging technologies should ideally be capable of visualizing a multiplexed panel of cancer biomarkers. Here, we demonstrate that the topical application and quantification of a multiplexed cocktail of receptor-targeted surface-enhanced Raman scattering (SERS) nanoparticles (NPs) enables rapid quantitative molecular phenotyping (QMP) of the surface of freshly excised tissues to determine the presence of disease. In order to mitigate the ambiguity due to nonspecific sources of contrast such as off-target binding or uneven delivery, a ratiometric method is employed to quantify the specific vs. nonspecific binding of the multiplexed NPs. Validation experiments with human tumor cell lines, fresh human tumor xenografts in mice, and fresh human breast specimens demonstrate that QMP imaging of excised tissues agrees with flow cytometry and immunohistochemistry, and that this technique may be achieved in less than 15 minutes for potential intraoperative use in guiding breast-conserving surgeries.

Purpose: We previously showed that nuclear localization of the actin-binding protein, filamin A (FlnA), corresponded to hormone-dependence in prostate cancer. Intact FlnA (280 kDa, cytoplasmic) cleaved to a 90 kDa fragment which translocated to the nucleus in hormone-naI« ve cells, whereas in hormone-refractory cells, FlnA was phosphorylated, preventing its cleavage and nuclear translocation. We have examined whether FlnA localization determines a propensity to metastasis in advanced androgen-independent prostate cancer. Experimental Design: We examined, by immunohistochemistry, FlnA localization in paraffinembedded human prostate tissue representing different stages of progression. Results were correlated with in vitro studies in a cell model of prostate cancer. Results: Nuclear FlnA was significantly higher in benign prostate (0.6612 F 0.5888), prostatic intraepithelial neoplasia (PIN; 0.6024 F 0.4620), and clinically localized cancers (0.69134 F 0.5686) compared with metastatic prostate cancers (0.3719 F 0.4992, P = 0.0007). Cytoplasmic FlnA increased from benign prostate (0.0833 F 0.2677), PIN (0.1409 F 0.2293), localized cancers (0.3008 F 0.3762, P = 0.0150), to metastases (0.7632 F 0.4414, P < 0.00001). Logistic regression of metastatic versus nonmetastatic tissue yielded the area under the receiver operating curve as 0.67 for nuclear-FlnA, 0.79 for cytoplasmic-FlnA, and 0.82 for both, indicating that metastasis correlates with cytoplasmic to nuclear translocation. In vitro studies showed that cytoplasmic localization of FlnA induced cell invasion whereas nuclear translocation of the protein inhibited it. FlnA dephosphorylation with the protein kinaseA inhibitor H-89 facilitated FlnA nuclear translocation, resulting in decreased invasiveness and AR transcriptional activity, and induced sensitivity to androgen withdrawal in hormone-refractory cells. Conclusions:The data presented in this study indicate that in prostate cancer, metastasis correlates with cytoplasmic localization of FlnA and may be prevented by cleavage and subsequent nuclear translocation of this protein.Filamins are a family of cytoskeletal proteins that organize filamentous actin into networks and stress fibers (1). Filamin A (FlnA) is a 280 kDa non -muscle actin binding protein, the appropriate function of which is essential for development (2, 3). FlnA dimerization forms a V-shaped flexible structure which can induce high-angle orthogonal branching and efficiently gather actin filaments into a three-dimensional gel in vitro by cross-linking actin filaments at the leading edge of migrating cells. Hence, filamins are essential for mammalian cell locomotion, anchoring of transmembrane proteins including integrins, and also act as interfaces for protein-protein interaction (4). More than 30 proteins of great functional diversity are known to interact with filamins which function as a signaling scaffold by connecting and coordinating a large variety of cellular processes (4).In prostate cancer, a role for FlnA was identified in prost...

No abstract