Disease relevance of RPIB9

• RPIP9 was activated in a high proportion of breast carcinomas (61.6%; n = 60) and a significant correlation with metastatic lymph node invasion (N = 0-3 vs. N > 3, where N = number of lymph nodes invaded; p = 0.031) was found [1].
• We developed sensitive methods for detecting and quantifying RPIP9 mRNA and used it to identify these transcripts in normal human tissues, 60 biopsies of primary breast carcinoma, in isolated epithelial cells both from the primary tumor and from associated lymph nodes, and from bone marrow biopsies of 74 breast cancer patients [1].

High impact information on RPIB9

• Although the mechanisms that lead to the CGI methylation of these genes are unknown, bisulfite sequencing of the promoter of RPIB9 suggests that expression is inhibited by methylation within SP1 and AP2 transcription factor binding motifs [2].
• RPIP9 mRNA could be detected in malignant epithelial cells isolated from the primary tumor and from metastasized lymph nodes as well as in the bone marrow of significantly more poor-prognosis (N > 3) than better-prognosis (N = 0-3) patients (p = 0.001) [1].
• RPIP9 is expressed at high levels in normal testis, brain and adrenal gland, and at very low levels in normal breast [1].
• Therefore, activation of RPIP9 occurs during the malignant breast epithelial transformation and increases with progression toward an invasive phenotype [1].
• Tumorigenic breast carcinoma cell lines expressed RPIP9, whereas MCF-10A and HBL-100 that do not form tumors in nude mice had undetectable levels of RPIP9 mRNA [1].

References