Disease relevance of GABRP

• Systematic characterisation of GABRP expression in sporadic breast cancer and normal breast tissue [1].
• Analysis of the cancer profiling array revealed a more than 2-fold downregulation of GABRP (p < 0.001) in 76% of primary breast carcinomas (n = 50) compared to corresponding normal tissues [1].
• Non-radioisotopic ISH showed strong GABRP expression in normal epithelial and benign papilloma breast cells, but no signal could be detected in invasive ductal carcinoma [1].

High impact information on GABRP

• The GABRA1 and GABRP findings were replicated in the second stage in an independent German family-based sample (P=0.0015-0.043) [2].
• In the first stage, associations were detected in a Portuguese patient sample with single nucleotide polymorphisms (SNPs) and haplotypes in GABRA1 (P=0.00062-0.048), GABRP (P=0.0024-0.042), and GABRA6 (P=0.0065-0.0088) [2].
• Using cDNA dot blot hybridisation (cancer profiling array), quantitative RT-PCR and non-radioisotopic in situ hybridisation (ISH), we have analysed GABRP expression in breast cancer and normal breast tissues as well as in nontumorigenic and tumorigenic breast cell lines [1].
• Furthermore, a significant downregulation of GABRP was noted in large (pT3-pT4) (p = 0.044) primary breast tumours [1].
• GABRP is located on chromosome 5q34 and it encodes the pi-subunit of the gamma-aminobutyric acid (GABA) receptor, a transmembrane protein expressed in the brain and several nonneuronal tissues [1].

Chemical compound and disease context of GABRP

• GABRP downregulation in breast cancer was confirmed by quantitative RT-PCR in cryopreserved breast tumour and normal breast tissue specimens (n = 22), in archival formalin-fixed, paraffin-embedded tissue specimens (n = 32), as well as in breast cancer cell lines (n = 8) [1].

Biological context of GABRP

• We had observed markedly elevated gene expression of gamma-aminobutyric acid type A (GABA(A)) receptor subunit pi (GABApi, GABRP) in some breast cancers with ER-/HER2- phenotype [3].
• The GABRP gene has been previously identified by in silico analysis of four million ESTs as a candidate gene differentially expressed in breast cancer [1].

Other interactions of GABRP

• METHOD: Using this assay, peripheral blood samples were analyzed for expression levels of mammaglobin and three complementary transcribed breast cancer-specific genes: B305D, gamma-aminobutyrate type A receptor pi subunit (GABA pi; GABRP), and B726P [4].

Analytical, diagnostic and therapeutic context of GABRP

• Quantitative RT-PCR in a panel of 23 normal human tissues showed that the GABRP expression level was most abundant in the normal breast tissues compared to other human tissues [1].

References