<title>Detection of prostaglandin H synthase (cyclooxygenase) -1 and -2 expression in single cancer cells by confocal Raman microspectroscopy</title>

Abstract

Prostaglandin H synthase (PGHS), commonly known as cyclooxygenase (COX), is the enzyme involved in the synthesis of biologically active prostanoids from arachidonic acid. There are two PGHS isozymes with identical functions, similar sizes and similar structures. PGHS-1 is constitutively expressed in most mammalian cells where as PGHS-2 is induced by various agents. PGHS-2 expression was increased with inflammation, mitogenesis, and some types of cancer. We have developed a method to simultaneously detect PGHS-1 and PGHS-2 in single cancer cells by using specific antibodies, surface-enhanced Raman scattering, and confocal Raman microspectroscopy. Cells were plated, cultured, incubated for immunocomplexation, and detected directly in the wells of a multiwell plate. The expression and localization of PGHS-1 and-2 in single malignant human hepatocytes was detected and compared to normal cells. Furthermore, the correlation between the expression of PGHS and the invasiveness of cancer cells was investigated in PC-3 cell sublines.

Highly Sensitive Measurement of Horseradish Peroxidase Using Surface-Enhanced Raman Scattering of 2,3-Diaminophenazine

“…In other words, the product should have both a high Raman scattering cross-section and a high affinity for the metal surface used for enhancement. Several substrates have been tested up to date: o -phenylenediamine (oPD) [ 14 , 15 , 23 , 24 , 25 , 26 , 27 , 28 ], 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) [ 16 ], 3,3′,5,5′-tetramethylbenzidine (TMB) [ 17 , 18 , 19 ], and leuco dyes [ 11 ]. Among these, oPD appears to be the most promising.…”