Background: The p33ING1b gene is involved in the p53-dependent response to DNA damage following exposure to ultraviolet radiation, and has recently been reported to be mutated in 20% of melanoma tumours.
Objectives: We sought to assess the p33ING1b mutation rate in our large panels of fresh melanomas and melanoma cell lines.
Methods: We screened 83 primary melanomas and 55 melanoma cell lines for mutations in p33ING1b by single-strand conformational polymorphism analysis and by direct sequencing.
Results: In contrast to previous reports, we found no somatic p33ING1b mutations in our panel of melanomas. We found that some of the discrepancy between our results and previously published studies may be due to inadvertent amplification of the ING1 pseudogene (INGX), and/or contamination of some samples with murine Ing1.
Conclusions: p33ING1b mutations in melanoma are rare. We have highlighted the importance of allele-specific primer design to avoid pseudogene amplification, and also the necessity to confirm the genetic identity and species of origin of individual cell lines. Further studies are needed to clarify the possible role of p33ING1b in melanoma tumorigenesis.