Expression of UBE2Q2, a Putative Member of the Ubiquitin-conjugating Enzyme Family in Pediatric Acute Lymphoblastic Leukemia

Acute lymphoblastic leukemia (ALL) is a cancer of the white blood cells most commonly found in childhood with a peak incidence at 2–5 years of age. The ubiquitin degradation pathway facilitates degradation of damaged proteins and regulates the growth and stress response. This pathway is activated in various cancers, including ALL. It has been previously reported that the newly characterized human gene UBE2Q2, a putative member of the ubiquitin-conjugating enzyme family, is over-expressed in the tumor mass and invasive epithelium in head and neck squamous cell carcinoma and breast cancer. Here, we have used quantitative reverse transcriptase polymerase chain reaction (RT-PCR) to assess expression of the UBE2Q2 gene in bone marrow samples of 20 children with ALL. Whole blood samples of 20 normal children were used as control specimens. RT-PCR revealed the expression of UBE2Q2 mRNA in 80% of the bone marrow samples from ALL patients as well as in 85% of leukemic normal peripheral blood cells. According to the results of quantitative RT-PCR, the levels of UBE2Q2 mRNA expression in the bone marrow cells of 11 out of the 20 children with ALL (55%) were significantly higher (> 2–47 fold) than those in blood cells of normal children. Our data suggest that the newly characterized human gene, UBE2Q2, may have implications for the pathogenesis of ALL and could be used for molecular diagnosis purposes in the future.