Quantitative ratiometric discrimination between noncancerous and cancerous prostate cells based on neuropilin-1 overexpression

Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106-9510, USA.
Proceedings of the National Academy of Sciences (Impact Factor: 9.67). 09/2011; 108(40):16559-64. DOI: 10.1073/pnas.1109490108
Source: PubMed


A multiplexed, ratiometric method is described that can confidently distinguish between cancerous and noncancerous epithelial prostate cells in vitro. The technique is based on bright surface-enhanced resonance Raman scattering (SERRS) biotags (SBTs) infused with unique Raman reporter molecules, and carrying cell-specific peptides. Two sets of SBTs were used. One targets the neuropilin-1 (NRP-1) receptors of cancer cells through the RPARPAR peptide. The other functions as a positive control (PC) and binds to both noncancerous and cancer cells through the HIV-derived TAT peptide. Point-by-point 2D Raman maps of the spatial distribution of the two tags were constructed with subcellular resolution from cells simultaneously incubated with the two sets of SBTs. Averaging the SERRS signal over a given cell yielded an NRP/PC ratio from which a robust quantitative measure of the overexpression of the NRP-1 by the cancer cell line was extracted. The use of a local, on-cell reference produces quantitative, statistically robust measures of overexpression independent of such sources of uncertainty as variations in the location of the focal plane, the local cell concentration, and turbidity.

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    • "Then, it was subsequently found to bind to VEGF which is a critical pro-angiogenic factor that induces proliferation and migration of endothelial cells to tumor vasculature. NRP-1 is reported to be up-regulated in cells of several cancers such as glioma [10], prostate carcinoma [11], breast cancer [12], gastric cancer [13], pancreatic carcinoma [14], colon cancer [15] and acute myeloid leukemia [16]. Recent studies have indicated that the overexpression of NRP-1 may enhance tumor angiogenesis and tumor growth in vivo. "
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