The Human T-Box Mesodermal Transcription Factor Brachyury Is a Candidate Target for T-Cell–Mediated Cancer Immunotherapy

Abstract

Purpose: Identification of tumor antigens is essential in advancing immune-based therapeutic interventions in cancer. Particularly attractive targets are those molecules that are selectively expressed by malignant cells and that are also essential for tumor progression. Experimental Design and Results: We have used a computer-based differential display analysis tool for mining of expressed sequence tag clusters in the human Unigene database and identified Brachyury as a novel tumor antigen. Brachyury, a member of the T-box transcription factor family, is a key player in mesoderm specification during embryonic development. Moreover, transcription factors that control mesoderm have been implicated in the epithelial-mesenchymal transition (EMT), which has been postulated to be a key step during tumor progression to metastasis. Reverse transcription-PCR analysis validated the in silico predictions and showed Brachyury expression in tumors of the small intestine, stomach, kidney, bladder, uterus, ovary, and testis, as well as in cell lines derived from lung, colon, and prostate carcinomas, but not in the vast majority of the normal tissues tested. An HLA-A0201epitope of human Brachyury was identified that was able to expand T lymphocytes from blood of cancer patients and normal donors with the ability to lyse Brachyury-expressing tumor cells. Conclusions: To our knowledge, this is the first demonstration that (a) a T-box transcription factor and (b) a molecule implicated in mesodermal development, i.e., EMT, can be a potential target for human T-cell^mediated cancer immunotherapy.

Specificity of brachyury in the distinction of chordoma from clear cell renal cell carcinoma and germ cell tumors: a study of 305 cases

“…Although this finding contrasts with other reports of brachyury immunoreactivity in germ cell tumors (both seminoma 3 and unspecified subtypes 5 ) and non-neoplastic testis (spermatogonia), 5,7 it should be noted that both studies describe and/or depict immunoreactivity that is very focal in nature. Given the reports of high brachyury mRNA expression in testicular carcinoma (type unspecified) with low level expression in normal testis, 11 theoretically, it would not be totally unexpected to find immunoreactivity for brachyury in paraffin sections. The different results in these studies may potentially be secondary to differences in staining methodology; however, our chordoma controls showed strong and diffuse nuclear reactivity with brachyury and we utilized both the same antibody and the same dilution as reported previously.…”

ΔNp63 transcriptionally regulatesbrachyury, a gene with diverse roles in limb development, tumorigenesis and metastasis

“…19 Interestingly, brachyury plays diverse roles in biology with critical functions during embryonic development and in tumorigenesis. [20][21][22] The apical ectodermal ridge (AER) is a thickened ridge of ectoderm that is essential for limb morphogenesis. 23,24 Brachyury is expressed in the mesoderm at the onset of limb formation, and mice mutant for brachyury exhibit a disruption in AER morphogenesis.…”

“…Brachyury also regulates epithelial to mesenchymal transition (EMT) and mesenchymal to epithelial transition (MET), which in addition to being critical processes in development are also involved in tumor metastasis. [20][21][22] Recently, the phenotypes of the p63 mutant mice are complex and diverse. the p63 -/-mice develop severe defects in morphogenesis of ectodermal appendages, and p63 +/-mice are tumor prone.…”

“…6,19 To determine whether p63 binds to this site on the promoter of brachyury, we performed chromatin immunoprecipitation (ChIP) assay using nuclear extracts from wildtype and p63 -/-mouse embryonic fibroblasts (MEFs) derived from E13.5 embryos. Using two distinct antibodies for p63, brachyury has been shown to be upregulated in a variety of tumors and tumor cell lines, including those of the small intestine, stomach, kidney, bladder, uterus, ovary, testis, lung, colon and prostate, 21 and chordoma, a rare malignant bone tumor. 22,25 The p63 mutant mice display multiple defects including failure of proper limb formation and tumor formation in heterozygous mice.…”

“…1,30 Additionally, other studies indicate that brachyury is also highly expressed in several human cancers. 21,22,25 To ask whether ∆Np63 expression correlates with brachyury expression in tumors, we performed q-RT PCR using tumor cell lines from p53 +/-and p53 +/-;p63 +/-mice with varying levels of ∆Np63 (Fig. 4A).…”