Mutation analysis and mRNA expression of trail-receptors in human breast cancer.
The chromosome region 8p12-p22 shows frequent allelic loss in a variety of human malignancies, including breast cancer (BC). The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-receptors TRAIL-R1, -R2, -R3 and -R4 are located on 8p21-p22 and might be candidate tumor suppressor genes in this region. To evaluate the involvement of TRAIL receptors in breast carcinogenesis, we have analyzed the entire coding region of TRAIL-R2 and the death domain (DD) regions of TRAIL-R1 and -R4 for the detection of somatic mutations in a series of breast tumors, lymph node metastases and BC cell lines. Overall, we detected 1, 11 and 3 alterations in the TRAIL-R1, -R2 and -R4 genes, respectively. Although functional studies have not yet been performed, we assume that most of these alterations do not alter the function of TRAIL-receptors. Additionally, we analyzed individuals from BC families for the detection of TRAIL-R2 germline mutations. One alteration has been found in the Kozak consensus motif at position -4 with respect to the translation initiation AUG [1-4 (C-->A)]. We further studied the mRNA expression of TRAIL and the 4 TRAIL receptors. In BC cell lines, a strongly decreased mRNA expression of TRAIL, TRAIL-R1, -R3 and -R4 was found, whereas the expression of TRAIL-R2 was only slightly reduced. In breast tumors, a 1.2-3.6-fold reduction of mRNA signals of the 5 genes was observed. No correlation was found between the expression level of TRAIL and the receptor mRNAs and clinicopathologic variables and between the expression of TRAIL-R2 and TP53 mutation status and loss of heterozygosity (LOH) at 8p21-p22. Taken together, we cannot exclude the involvement of TRAIL-receptors in BC. Our mutation studies indicate that DD receptor mutations occur at low frequency and are not the primary cause for the altered mRNA expression of TRAIL and TRAIL-receptors in BC.
Seitz
Susanne
S
Abteilung Tumorgenetik, Max-Delbrück-Centrum für Molekulare Medizin, Robert-Rössle-Strasse 10, 13092 Berlin, Germany. sseitz@mdc-berlin.de
Wassmuth
Peter
P
Fischer
Jörg
J
Nothnagel
Anita
A
Jandrig
Burkhard
B
Schlag
Peter M
PM
Scherneck
Siegfried
S
D000328:Adult; D000368:Aged; D001940:Breast / Q000378:metabolism; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology; D002898:Chromosomes, Human, Pair 8; D004252:DNA Mutational Analysis; D005260:Female; D016158:Genes, p53; D006801:Humans; D008875:Middle Aged; D009154:Mutation; D012333:RNA, Messenger / Q000032:analysis*; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D018124:Receptors, Tumor Necrosis Factor / Q000235:genetics*
D012333:RNA, Messenger; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D018124:Receptors, Tumor Necrosis Factor; C105190:TNFRSF10A protein, human; C505639:TNFRSF10B protein, human