In vitro study on the effect of doxorubicin on the proliferation markers MCM3 and Ki-67

Purpose: Aberrant proliferation is an essential feature of cancer cells, which can be caused by alterations in components of the cell cycle, such as minichromosome maintenance protein-3 (IVIC1V13) and Ki-67. Doxorubicin is a cytotoxic/cytostatic anticancer agent commonly used in chemotherapy. We investigated the effect of this drug on MCM3 and Ki-67 in the KB cell line, which is considered a subline of HeLa cell line. Methods: KB cells were treated with doxorubicin and its effect on apoptosis, mRNA levels and protein expression of MCM3 and Ki-67 was determined by flow cytometry (annexin V-FITC/PI assay), quantitative real-time RT-PCR (qRT-PCR) and immunocytochemistry, respectively. Cytotoxicity was assessed using the MTT assay. One-way analysis of variance (ANOVA) was used for comparing groups and differences were assessed by a Tukey's post hoc test. Results: Protein expression of both biomarkers and MCM3 mRNA were not affected by doxorubicin, but Ki-67 mRNA significantly increased after treatment (p=0.049). Conclusions: Considering that doxorubicin can influence certain biochemical events that lead to modifications in Ki-67, this factor might be useful in evaluating the impact of anthracycline-based chemotherapeutic agents. Changes in MCM3 following doxorubicin treatment require further investigation.