Cytotoxic effects of Belotecan in the cervical cancer cell lines

Jeon, Chung Ra; Lee, Keun Ho; Oh, Eun Kyeong; Kim, Chan Joo; Park, Tae Chul; Park, Jong Sup

Abstract

OBJECTIVE
In our domestic market, Belotecan (Camptobel(R), chongkeundang, Korea) is newly introduced recently. Belotecan has many advantages of improved water solubility and fewer side effects like severe diarrhea or GI bleeding compare to other camptothecin derivatives. In this study, primary focus is aiming to evaluate the effectiveness of belotecan by providing the cytotoxicity and apoptotic pathway on cervical cancer cells.
METHODS
Cervical cancer cell line, HeLa and Caski were used. Belotecan applied on both cell lines and checked whether it has anti tumor effect on cancer cell by using MTT assay. DNA fragmentation and western blot was performed to confirm cellular apoptosis pathway. Also cDNA microarray and RT-PCR were serially carried out in order to identify responsible genes for apoptosis. RESULT: Dose- and time- dependent inhibition of cell proliferation is noted on the Belotecan applied HeLa and CaSki cervical carcinoma cell line by MTT assay. DNA fragmentation assay showed the DNA ladder indicating apopoptosis. Also apoptotic pathway and genes that are related with Belotecan activities are identified. Apoptosis, cell cycle, and drug metabolism related gene, and DNA repair gene were found to be differently regulated by treatment of Belotecan in HeLa cells. Among the DNA repair gene, RT-PCR reconfirmed the increased expression of CIB1(Calcium and intergrin binding 1), APEX1 (APEX nuclease 1) and the decresed expression of EXO1 (Exonuclease 1), WDR33 (WD repeat domain 33), and GADD45A (Growth arrest and DNA-damage-inducible, alpha).
CONCLUSION
The first domestically introduced 1st line anti- tumor agent, Belotecan shows its excellent inhibiting action on cervical cancer cell proliferation by apoptotic pathway in this study. Also genetic alterations in cDNA microarray leads to the new fact that Belotecan, as a topoisomerase I inhibitor, is not only involved with apoptotic, cell cycle-related pathway but also involved in DNA repair.