Purpose: Cross-contamination of cell lines is a serious but often unrecognized problem. We describe the authentication of a panel of transitional cell carcinoma cell lines using the short tandem repeat profiling technique to detect cross-contamination.
Materials and methods: Genomic DNA was isolated from UM-UC-1, UM-UC-2, UM-UC-3 (ATCC), UM-UC-6, UM-UC-9, UM-UC-10, UM-UC-11, UM-UC-13, UM-UC-14, UM-UC-16, T24 and KU7 cell lines. Short tandem repeat loci (D3S1358, D16S539, vWA, FGA, TH01, TPOX, CSF1PO, D5S818, D13S317 and D7S820) and a segment of the X-Y homologous gene amelogenin were co-amplified by polymerase chain reaction. Profiling was done using POP-4TM performance optimized polymer 4 (Applied Biosystems) with an ABI Prism 310 genetic analyzer. DNA sequencing of TP53 and immunohistochemistry for p53 were performed in UM-UC-3 and UM-UC-3-GFP.
Results: All cell lines had a unique short tandem repeat profile except UM-UC-2 and T24, which were virtually identical. T24 short tandem repeat profiles matched those of early passage number UM-UC-2. Stable transfection of the green fluorescence protein marker gene did not alter UM-UC-6, UM-UC-14 or KU7 profiles. However, the short tandem repeat profile for UM-UC-3-GFP was different from that of UM-UC-3. DNA sequencing showed a difference in TP53 between UM-UC-3 and UM-UC-3-GFP, confirming that UM-UC-3-GFP is not derived from UM-UC-3.
Conclusions: Short tandem repeat profiling provides a unique genetic signature of human cell lines that does not significantly change with passage or green fluorescence protein transduction. Using short tandem repeat profiling we noted that the cell line UM-UC-2 is T24. DNA fingerprinting using short tandem repeat profiling is an easy and reliable tool that can be used to verify cell lines.