Effect of paclitaxel (Taxol) on CA 125 expression and release by ovarian cancer cell lines

Two ovarian cancer cell lines, OVC432 and the newly established CVU4I, were used to study the effect of Taxal on cell growth and simultaneous CA 125 antigen expression. Growth of both cell lines was effectively inhibited by drug concentrations of 0.1 microM and higher. Complete inhibition of cell growth may result from high concentrations of Cremophor EL present in the Taxol formulation. Immunohistochemical analysis demonstrated that both cell lines retained the CA 125 expression on the cell surface during exposure to paclitaxel. This was reflected in a constant statistically significant correlation between cell numbers and CA 125 concentrations found in cell lysates. CA 125 levels in the culture medium showed a significant relation to cell numbers and, consequently, to the response of the cell line to the administered anticancer drug. It may be concluded from this study that CA 125 seems to be a reliable tumor marker in monitoring tumor response during paclitaxel treatment.

Ultrastructural study of virus-like particles in Chinese hamster lung cells

Virus-like particles were found in the E36 cells. One type, associated with centrioles, consisted of two concentric shells with a diam. of 50 to 60 nm. Some of these particles were seen budding through the plasma membrane giving rise to a free immature particle showing two concentric shells and an outer envelope. Concentration of the inner shell into a nucleoid results in a mature particle characterized by a nucleoid, mainly eccentrically located, surrounded by an intermediate layer and wrapped in an envelope. The diameter of the nature and immature particles was 75 to 85 nm. The morphogenesis of this virus-like particle resembles that of the oncoviruses.