[Differential invasion and metastasis capacities of methotrexate enantiomer-resistant A549 cell lines].

Objective: To study the differential in vitro motor and invasion capacities of methotrexate (MTX) enantiomer-resistant tumor cells.

Methods: The incremental concentrations and successive low-dose induction were employed to acquire the cell series resistant to 15 µmol/L MTX enantiomer, namely L-(+)-MTX/A549 and D-(-)-MTX/A549. Their drug-resistant indices were determined by MTT assay and their migration capacities by wound healing assay.

[Chiral selectivity in differentiation of lung cancer A549 cell to vascular endothelial cells after drug resistance induced by D-or L-methotrexate enantiomers].

Objective: To study the chiral selectivity in vascular endothelial differentiation in drug resistant lung cancer cells induced by high-dose L- or D-methotrexate (MTX) enantiomer.

Methods: Human lung cancer cells of the line A549 were co-cultured with high-dose (15 micromol/L) L- or D-MTX enantiomer so as to develop cancer cells resistant to MTX. MTT method was used to detect the drug resistant index.

High-performance capillary electrophoretic method for the quantification of global DNA methylation: application to methotrexate-resistant cells.

Global DNA hypomethylation in tumor tissue is a common characteristic in a variety of malignancies such as breast, colon, oral, lung, and blood cancers. A rapid and sensitive method has been developed for the determination of global DNA methylation in cells. Five substances--2'-deoxycytidine (dC), 5-methyl 2'-deoxycytidine (mdC), 2'-deoxyadenosine (dA), 2'-deoxythymidine (dT), and 2'-deoxyguanosine (dG)--were completely separated by high-performance capillary electrophoresis in 10 min.