Factor analysis of in vitro antitumor activities of platinum complexes.

Abstract

Factor analysis was applied to the data matrix of in vitro growth inhibitory activities of 52 platinum complexes against 9 tumor cell lines, L1210, P388, Lewis lung, AH66, AH66F, HeLa S3, KB, HT-1197 and HT-1376 cell lines. Three factors were obtained by the principal factor analysis method. After the varimax rotation of these three factors, tumor cell lines were classified into four groups according to their factor loadings. The platinum complexes were characterized by the factor scores. Cisplatin was situated in an extreme position as compared with the other platinum complexes. In vivo antitumor activities of the platinum complexes were tested against L1210 and LL murine tumor models. The in vivo activity against L1210 showed a negative correlation with that against LL. Factor 2 scores of the complexes obtained by factor analysis of in vitro antitumor activities showed a good correlation with these in vivo antitumor activities. Then, the structure-factor 2 score relationships among platinum complexes were analyzed by the Free-Wilson method. From this analysis, structure-activity relationships for carrier ligands and leaving groups are proposed. Factor analysis is suggested to be a useful method to establish an efficient screening system for platinum complexes.

Decreased plasma soluble erythropoietin receptor in high-altitude excessive erythrocytosis and Chronic Mountain Sickness

“…Several studies have provided evidence for a physiological role of sEpoR by direct competition for Epo with mEpoR, and also for an effect of hypoxia on sEpoR levels ( 5 , 9 , 23 , 26 , 32 , 43 ). It has been shown, for example, that changes in plasma sEpoR concentration influence the effect of Epo on Hb concentration ( 23 ).…”

“…Several studies have provided evidence for a role of sEpoR in modulating Epo signaling as sEpoR blocks Epo signaling in vitro and in vivo by direct competition for Epo with mEpoR ( 5 , 26 , 32 , 43 ). The presence of sEpoR has been reported in plasma and several tissues, including liver, spleen, kidney, muscle, brain, and bone marrow ( 14 , 32 , 43 ).…”

Soluble Erythropoietin Receptor Contributes to Erythropoietin Resistance in End-Stage Renal Disease

“…First, other investigators have shown that sEpoR may block EpoR signaling in vitro [25], [51]. Second there is recent data to suggest that sEpoR may inhibit erythropoietin signaling in vivo .…”

In Vivo Activity and Hydrophobicity of Cytostatic Aziridinyl Quinones

“…Pattern recognition techniques, like multivariate statistics, will be used in order to investigate activity and selectivity. Similar techniques have been successfully used on other cytostatic activity data. − These papers discouraged the use of one single experiment for the determination of biological activity. Principal component analysis helps in reducing data from a number of experiments to the underlying patterns of information. − New properties, called principal components, are derived by linear combination of the old properties, assigning contributions to the old properties in an interative manner.…”

“…Similar techniques have been successfully used on other cytostatic activity data. [35][36][37] These papers discouraged the use of one single experiment for the determination of biological activity. Principal component analysis helps in reducing data from a number of experiments to the underlying patterns of information.…”