Spermine oxidase (SMO) activity in breast tumor tissues and biochemical analysis of the anticancer spermine analogues BENSpm and CPENSpm

Background: Polyamine metabolism has a critical role in cell death and proliferation representing a potential target for intervention in breast cancer (BC). This study investigates the expression of spermine oxidase (SMO) and its prognostic significance in BC. Biochemical analysis of Spm analogues BENSpm and CPENSpm, utilized in anticancer therapy, was also carried out to test their property in silico and in vitro on the recombinant SMO enzyme. Methods: BC tissue samples were analyzed for SMO transcript level and SMO activity. Student’s t test was applied to evaluate the significance of the differences in value observed in T and NT samples. The structure modeling analysis of BENSpm and CPENSpm complexes formed with the SMO enzyme and their inhibitory activity, assayed by in vitro experiments, were examined. Results: Both the expression level of SMO mRNA and SMO enzyme activity were significantly lower in BC samples compared to NT samples. The modeling of BENSpm and CPENSpm complexes formed with SMO and their inhibition properties showed that both were good inhibitors. Conclusions: This study shows that underexpression of SMO is a negative marker in BC. The SMO induction is a remarkable chemotherapeutical target. The BENSpm and CPENSpm are efficient SMO inhibitors. The inhibition properties shown by these analogues could explain their poor positive outcomes in Phases I and II of clinical trials

Small scale spatial genetic structure of six tropical tree species in French Guiana

The small scale spatial genetic structure of six tropical tree species (Carapa procera, Chrysophyllum sanguinolentum, Dicorynia guianensis, Eperua grandiflora, Virola michelii, Vouacapoua americana) was studied for populations located within a sylvicultural trial in French Guiana. The analysed species have different biological and ecological characteristics with respect to spatial distribution, sexual system, pollen and seed dispersal agents, flowering phenology, and they differ in their environmental demands. The spatial position of trees and at least one data set on the genetic information for allozymes, cp-DNA marker, RAPDs and AFLPs served as basis for the analysis. As estimator for spatial genetic structure, Moran's index was computed for allozymes and cp-DNA markers, while for RAPDs and AFLPs mean Tanimoto distances between pairs of trees in different spatial distance classes were calculated. Each species showed significant spatial structure for at least one type of gene marker. The expansion of significant spatial genetic structures was relatively large and varied between 60m up to 800m. The strongest spatial autocorrelation was found for maternally inherited cp-DNA marker. Due to distinctly higher level of genetic variation, AFLPs and RAPDs were more sensitive to detect spatial structure than allozymes. Relations between the spatial genetic structures and the species' life characteristics are discussed