ABSTRACT
BACKGROUND: Previously published reports indicated that some enzymes of the central carbon metabolism (CCM), particularly those involved in glycolysis and the tricarboxylic acid cycle, may contribute to regulation of DNA replication. However, vast majority of such works was performed with the use of cancer cells, in the light of carcinogenesis. On the other hand, recent experiments conducted on bacterial models provided evidence for the direct genetic link between CCM and DNA replication. Therefore, we asked if silencing of genes coding for glycolytic and/or Krebs cycle enzymes may affect the control of DNA replication in normal human fibroblasts. RESULTS: Particular genes coding for these enzymes were partially silenced with specific siRNAs. Such cells remained viable. We found that silencing of certain genes resulted in either less efficient or delayed enterance to the S phase. This concerned following genes: HK2, PFKM, TPI, GAPDH, ENO1, LDHA, CS1, ACO2, SUCLG2, SDHA, FH and MDH2. Decreased levels of expression of HK2, GADPH, CS1, ACO2, FH and MDH2 caused also a substantial impairment in DNA synthesis efficiency. CONCLUSIONS: The presented results illustrate the complexity of the influence of genes coding for enzymes of glycolysis and the tricarboxylic acid cycle on the control of DNA replication in human fibroblasts, and indicate which of them are especially important in this process.
Subject(s)
Citric Acid Cycle/genetics , Enzymes/metabolism , Glycolysis/genetics , RNA Interference , Cell Line , DNA Replication , Enzymes/chemistry , Enzymes/genetics , Fibroblasts/cytology , Fibroblasts/metabolism , Humans , RNA, Messenger/metabolism , RNA, Small Interfering/metabolism , S PhaseABSTRACT
The potentiometric and conductometric titration methods have been used to characterize the stability of series of VO(IV)-, Co(II)- and Ni(II)-oxydiacetato complexes in DMSO-water solutions containing 0-50 % (v/v) DMSO. The influence of DMSO as a co-solvent on the stability of the complexes as well as the oxydiacetic acid was evaluated. Furthermore, the reactivity of the complexes towards superoxide free radicals was assessed by employing the nitro blue tetrazolium (NBT) assay. The biological properties of the complexes were investigated in relation to their cytoprotective activity against the oxidative damage generated exogenously by using hydrogen peroxide in the Human Dermal Fibroblasts adult (HDFa) cell line as well as to their antimicrobial activity against the bacteria (Bacillus subtilis, Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis). The relationship between physicochemical and biological properties of the complexes was discussed.
Subject(s)
Cobalt/chemistry , Coordination Complexes/chemistry , Coordination Complexes/pharmacology , Nickel/chemistry , Vanadates/chemistry , Anions/chemistry , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Bacillus subtilis/drug effects , Enterococcus faecalis/drug effects , Escherichia coli/drug effects , Microbial Sensitivity Tests , Pseudomonas aeruginosa/drug effects , Staphylococcus aureus/drug effects , Staphylococcus epidermidis/drug effectsABSTRACT
Dependence of carcinogenesis on disruption of DNA replication regulation is a well-known fact. There are also many reports demonstrating the interplay between transcription and DNA replication processes, particularly underlying the importance of promoter activities in the control of replication initiation. Recent findings have shown direct links between central carbon metabolism and DNA replication regulation. Here, we summarize previously published reports which indicated that enzymes of the central carbon metabolism, particularly those involved in glycolysis and the tricarboxylic acid cycle, may contribute to regulation of transcription and DNA transactions (replication and repair). In this light, we propose a hypothesis that some of these enzymes might be linkers between transcription, DNA replication, and carcinogenesis. If true, it may have a consequence in our understanding of causes and mechanisms of carcinogenesis. Particularly, certain metabolic perturbations might directly (through central carbon metabolism enzymes) influence regulation of DNA transactions (replication control and fidelity), and thus facilitate carcinogenesis. To test this hypothesis, further studies will be necessary, which is discussed in the final part of this article.
