Cyclin I mRNA Expression Correlates with Kinase Insert Domain Receptor Expression in Human Epithelial Ovarian Cancer
ANTICANCER RESEARCH
Authors: Cybulski, Marek; Jeleniewicz, Witold; Nowakowski, Andrzej; Stenzel-Bembenek, Agnieszka; Tarkowski, Rafal; Kotarski, Jan; Stepulak, Andrzej
Abstract
Background/Aim: Ovarian cancer is the second most common gynecological malignancy after cancer of the uterine corpus, and the fifth leading cause of cancer-related death among women. It has been discovered that cyclin I (CCNI) protein expression correlates with the proliferation of cancer cells and expression of angiogenesis-related proteins, such as vascular endothelial growth factor (VEGF) and VEGF receptor 2/kinase insert domain receptor (VEGFR2/KDR). We examined whether any association exists between mRNA expression of CCNI and KDR genes in epithelial ovarian cancer (EOC) tissues, clinicopathological parameters and patients' response to chemotherapy. Materials and Methods: Expression of CCNI and KDR genes was analyzed by quantitative real-time reverse transcription PCR in 40 human primary EOC tissues and four human ovarian cancer cell lines (TOV-112D, OV-90, OVCAR-3 and Caov-3). Results: CCNI and KDR mRNA expression was detected in all EOC tissues and ovarian cancer cell lines. The mRNA levels of both genes were significantly higher in EOC than in ovarian cancer cell lines (p<0.001). Neither CCNI nor KDR mRNA expression in EOC tissues was significantly associated with variables such as age, menopausal status, International Federation of Gynecology and Obstetrics (FIGO) stage, residual disease, patients' response to chemotherapy, tumor histology, grade or sensitivity to chemotherapy. However, we demonstrated a significant positive correlation between the mRNA expression of KDR and CCNI in EOC tissues (R=0.530, p<0.001). Conclusion: Neither CCNI nor KDR mRNA expression predicts response of patients with EOC to platinum-based first-line chemotherapy. Cyclin I may be involved in angiogenesis in EOC, which needs further investigation.
MOLECULAR-CLONING AND ANALYSIS OF CDC28 AND CYCLIN HOMOLOGS FROM THE HUMAN FUNGAL PATHOGEN CANDIDA-ALBICANS
MOLECULAR AND GENERAL GENETICS
Authors: SHERLOCK, G; BAHMAN, AM; MAHAL, A; SHIEH, JC; FERREIRA, M; ROSAMOND, J
Abstract
In the budding yeast Saccharomyces cerevisiae, progress of the cell cycle beyond the major control point in G1 phase, termed START, requires activation of the evolutionarily conserved Cdc28 protein kinase by direct association with G1 cyclins. We have used a conditional lethal mutation in CDC28 of S. cerevisiae to clone a functional homologue from the human fungal pathogen Candida albicans. The protein sequence, deduced from the nucleotide sequence, is 79% identical to that of S. cerevisiae Cdc28 and as such is the most closely related protein yet identified. We have also isolated from C. albicans two genes encoding putative G1 cyclins, by their ability to rescue a conditional G1 cyclin defect in S. cerevisiae; one of these genes encodes a protein of 697 amino acids and is identical to the product of the previously described CCNI gene. The second gene codes for a protein of 465 residues, which has significant homology to S. cerevisiae Cln3. These data suggest that the events and regulatory mechanisms operating at START are highly conserved between these two organisms.