Expression of ubiquitin-conjugating enzyme E2C/UbcH10 in astrocytic tumors

UbcH10 is one of the key regulators of cell cycle progression through the mitotic spindle assembly checkpoint pathway. Recently, aberrantly high UbcH10 expression has been demonstrated in a variety of malignancies. However, its role in astrocytic carcinogenesis is not well defined. This study investigated the splice pattern of the UbcH10 gene and its expression status in astrocytomas of different grades. Consequently, UbcH10 splice variant I (GenBank accession nos. NM_007019) was detected in astrocytomas and normal brain tissues by RT-PCR and sequence analysis. Expression levels of UbcH10 mRNA were elevated in high-versus low-grade astrocytomas (64.33 +/- 60.98 vs 8.36 +/- 8.15, respectively; p=0.000) or normal controls (64.33 +/- 60.98 vs 1.00 +/- 137, respectively; p=0.000), as determined by quantitative real time PCR analysis. Similarly, immunohistochemistry study showed increased UbcH10 labelling index in high-grade astrocytomas versus low-grade tumors (10.53 +/- 5.79% vs 4.23 +/- 2.85%, respectively; p = 0.000) or normal controls (10.53 +/- 5.79% vs 0.0 +/- 0.0%, respectively; p=0.000) and, a positive correlation between UbcH10 immunoreactivity and Ki-67 immunostaining was also noted (Spearman r=0.63, p<0.001). These data suggest that overexpression of UbcH10 may serve as one important molecular mechanism that underlies the astrocytic carcinogenesis. (C) 2008 Elsevier B.V. All rights reserved.