Misidentification of Putative Medullary Thyroid Cancer Cell Lines RO-H85-1 and RO-D81-1

Abstract

In 2008, the JCEM published a landmark paper showing redundancy or misidentification of almost 50% of a panel of 40 commonly used differentiated and anaplastic thyroid cancer cell lines (1); this finding had significant implications for the thyroid cancer research field (2). We have just found, by DNA fingerprinting (3), that two putative medullary thyroid cancer (MTC) cell lines appear to be misidentified. The cell lines are RO-H85-1 and RO-D81-1 (4). DNA fingerprinting was performed using the StemElite kit (Promega Corp, Madison, Wisconsin). A search of the ATCC (www.atcc.org) and DSMZ (www.dsmz.de) short tandem repeat (STR) databases revealed that RO-H85-1 appears to be closely related (82%) to the bladder cancer cell line 647-V, and RO-D81-1 appears to be highly related (100%) to the colon cancer cell line HT-29 (Table 1). For convenience, the STR genotypes of two commonly used MTC cell lines, TT and MZ-CRC-1, are included in Table 2. These cell lines have nonredundant genotypes, supporting their integrity as distinct cell lines. The genotype of the TT cell line is also available in the ATCC STR database. The initial report of the RO-H85-1 and RO-D81-1 cell lines (4) indicated that RO-H85-1 produced calcitonin, but RO-D81-1 did not. We received the RO-H85-1 and RO-D81-1 cell lines in 1990, and these stocks were frozen after 1 passage. Both 647-V (5) and HT-29 (6) were established prior to establishment of the RO-H85-1 (1985) and RO-D81-1 (1981) cell lines. We did not have either HT-29 or 647-V in our laboratory. Therefore, it appears likely that cross-contamination occurred before we received these cell lines. We share this information with the thyroid cancer research community to prevent potential futile research on MTC.