Mechanisms Underlying Chemoresistance of Choriocarcinoma Investigated with NMR-Based Metabonomics

Abstract

Choriocarcinoma (CC) is a malignant trophoblastic tumor that occurs in women of childbearing age. Its cure rate could be over 90% following single drug or multidrug chemotherapy with methotrexate, 5-fluorouracil and etc. Chemoresistance is the main cause of treatment failure in CC, and the mechanisms have yet to be elucidated. Most of the previous works on the chemoresistance of CC focused on the transcript and protein levels, and much less attention was put on the metabolic level. In this study, the metabolomic phenotypes of two lines of CC cell, methotrexate-resistant cell (JEG3R) and methotrexate-sensitive cell (JEG3), as well as the medium extracts, were investigated using an NMR-based metabonomics method. The results showed that the chemoresistance of CC was likely related to disturbed glucose metabolism. Glucitol accumulation was observed only in the JEG3R cell line, suggesting the involvement of aldose reductase in the development of chemoresistance. In addition, methotrexate chemoresistance was also associated with lactate accumulation and stimulated alanine synthesis to fuel the Krebs cycle. The levels of amino acids, nucleotides and phosphocholine in the resistant line showed significant differences from the non-resistant line, and positive correlations with the proliferation rate of CC. This study provided insights into the chemoresistance of CC from the metabolism aspect.

Keywords

• choriocarcinoma
• chemoresistance
• glucitol
• metabonomics