<i>ARID1A</i> mutations and expression in UBC.

<p><i>Panel A</i>. A G>C transversion identified through Solexa resequencing, confirmed by Sanger sequencing of independent PCR products, leading to a predicted Q2210H substitution in VMCUB-3 cells. <i>Panel B</i>. Western blotting analysis in a panel of UBC cell lines identifies a subset with undetectable expression, including VMCUB-3. mRNA expression was analyzed by RT-qPCR; results are shown as values normalized with respect to the housekeeping gene <i>HPRT</i>. <i>Panel C</i>. A C>T mutation in codon 403, leading to a premature stop codon, was identified in a primary T1G3 tumor. The mutation was absent from matched normal leukocyte DNA. Lack of protein expression in the corresponding tumor tissue was confirmed using immunohistochemistry. The red arrowhead points to a tumor cell lacking ARID1A staining, whereas the black arrowhead indicates a positive stromal cell. For comparison, a TaG1 tumor with wild type <i>ARID1A</i> sequence is shown.