Targeting Thioredoxin Reductase 1 Reduction in Cancer Cells Inhibits Self-Sufficient Growth and DNA Replication
Figure 1
Thioredoxin reductase (TR1) expression in mouse and human malignant cells.
Indicated cell lines were metabolically labeled with 75Se, the resulting protein cell extracts electrophoresed and the gels exposed to a PhosphorImager (see Methods). Selenoproteins identified previously in cell extracts [25], [26] are indicated by an arrow and name on the right of each panel. TR1 was also identified by western blotting in protein extracts of each cell line as shown in the lower panels. (A, left panel) Control (parental; NIH3T3) and DT cells. (A, right panel) NIH3T3 (control, parental cells used in generating DT cells), LLC1 (mouse Lewis lung cell carcinoma), ACHN (human kidney renal cell carcinoma), A549 (human lung non-small cell carcinoma), HCT116 (human colon cell adenocarcinoma) and SNB19 (human cell glioblastoma). NIH3T3 was used as an indicator cell line for comparison of TR1 levels in a normal cell line to the malignant cell lines. (B) DT/pU6-m3 and DT/siTR1. DT (obtained by overexpression of mutant k-ras in NIH3T3) cells were stably transfected with the pU6-m3 (control) vector or siTR1 knockdown vector, respectively (see Methods).