Identification of Human Autologous Cytotoxic T-Lymphocyte-Defined Osteosarcoma Gene That Encodes a Transcriptional Regulator, Papillomavirus Binding Factor

Abstract

The prognosis for patients with osteosarcoma who do not respond to current chemotherapy protocols still remains poor. Toward the goal of establishing efficacious peptide-based immunotherapy for those patients, we previously developed an autologous pair of CTLs and an osteosarcoma cell line. In the current study, we screened the cDNA library of this osteosarcoma cell line using an autologous CTL clone and identified cDNA encoding an antigen. The isolated cDNA was identical to papillomavirus binding factor (PBF), which was recently reported as a DNA binding transcription factor cooperating with RUNX1. Reverse transcription-PCR analysis revealed that PBF was expressed in 16 of 19 cases of bone and soft-tissue sarcoma cell lines (5 of 6 of osteosarcoma lines) and 57 of 76 sarcoma tissue samples (11 of 14 of osteosarcoma tissues). Also, PBF was expressed in 10 of 13 epithelial cancer cell lines and 20 of 34 of cancer tissues. In contrast, PBF was detected in some normal organs including ovary, pancreas, spleen, and liver by reverse transcription-PCR but was restricted in the cytoplasm by immunostaining and undetectable by Western blotting. Furthermore, a 12-mer peptide, CTACRWKKACQR, located at the COOH terminus of PBF, was found to be a minimum requirement for recognition by the CTL clone in the context of the HLA-B*5502 molecule. These findings suggest that PBF is a shared tumor-associated antigen, which may serve as a source of peptides applicable to peptide-based immunotherapy for osteosarcoma and other malignant tumors.

The Glucose Transporter (GLUT4) Enhancer Factor Is Required for Normal Wing Positioning in Drosophila

“…Glut4EF ½also called the Huntington's disease gene regulatory regionbinding protein (HDBP) 1 (Tanaka et al 2004) and SLC2A4RG was originally characterized and named for its ability to bind to the enhancer of the Glucose Transporter 4 gene (Oshel et al 2000). Glut4EF proteins are also highly similar to papillomavirus binding factor (PBF) (Boeckle et al 2002), also called HDBP2 (Tanaka et al 2004), osteosarcoma antigen (Tsukahara et al 2004), and ZNF395 (Stoeckman et al 2006) (Figure 4A), and in our search of the database we found a previously uncharacterized human EST ZNF704 ½similar to the mouse EST Zfp704 (Blackshaw et al 2004), also called mouse glucocorticoid-induced gene 1 (Gig1) that was highly related to Glut4EF proteins and represents a third mammalian family member ( Figure 4A). Therefore, the gene disrupted in stretch mutants represents the Drosophila member of a new family of transcription factors conserved from Drosophila to mammals.…”

“…Taken together, our results provide new insights into the importance of Glut4EF family transcription factors in patterning of the developing organism. In light of the possibility that Glut4EF family transcription factors may play roles in type 2 diabetes (McGee and Hargreaves 2006), in Huntington's disease (Tanaka et al 2004), and in several human cancers (Boeckle et al 2002;Tsukahara et al 2004), future work will be directed at further understanding the molecular mechanisms of Glut4EF's action.…”

VHL Deficiency Drives Enhancer Activation of Oncogenes in Clear Cell Renal Cell Carcinoma

“…Targeting ZNF395 or its downstream effectors in future studies may be therapeutically relevant to both ccRCC and other hypoxic solid malignancies. Direct targeting of ZNF395 using a peptidebased cancer vaccine is undergoing phase I trials in patients with sarcoma (107)(108)(109), opening up the possibility of using immunotherapy to target the extracellular fragments of nuclear master regulators. Our study suggests that initiating a similar trial in ccRCC may be worthwhile.…”

Side population cells have the characteristics of cancer stem-like cells/cancer-initiating cells in bone sarcomas

“…Moreover, it might become possible to identify CTL-defined CSC-specific tumour antigens for immunotherapy targeting CSCs. Thus far, we have been trying to identify CTLdefined tumour antigens by forward and reverse immunological approaches and have carried out antigenic peptide vaccination trials in bone and soft tissue sarcomas (Sato et al, 2002;Ida et al, 2004;Tsukahara et al, 2004Tsukahara et al, , 2008aTsukahara et al, , b, 2009Kawaguchi et al, 2005;Kimura et al, 2008). Currently, we are trying to establish autologous CTL clones recognising SP cells of MFH2003 from tumour-infiltrating lymphocytes.…”