Figure 1

HJURP is overexpressed in human breast cancer cell lines and primary breast tumors. (a) Protein levels of HJURP (Holliday junction recognition protein) in a large panel of human breast cancer cell lines and immortalized non-malignant mammary epithelial cells were assessed by Western blotting. Samples 30, 31 and 62 are immortalized non-malignant mammary epithelial cells 184A1N4, 184B5 and S1 respectively. (b) Normalized quantification of HJURP protein levels in the cell lines using Scion Image software are shown. The arrows indicate the immortalized non-malignant mammary epithelial cells 184A1N4, 184B5, and S1 respectively. The line shows M+1.95*SE where M is mean of 184A1N4, 184B5 and S1 protein levels and SE is standard error of 184A1N4, 184B5 and S1 protein levels. Protein level above this line was defined as overexpression. About 50% breast cancer cell lines have overexpression of HJURP. (c) Figure 1c shows the correlation between mRNA and protein levels of HJURP in human breast cancer cell lines. HJURP expression is measured as log₂ (probe intensities) by Affymetrix microarray. The detail for protein quantification refers to Materials and Methods. R was Spearman's rho correlation coefficient. The two-tailed P -value was obtained from Spearman correlation test. (d) The HJURP protein level has a negative and significant correlation with the doubling times of cell lines. (e) HJURP mRNA expression level is significantly evaluated in invasive ductal carcinomas (IDC) in comparison to normal breast ducts. HJURP mRNA expression is assessed by Affymetrix microarray. HJURP expression is measured as log₂ (probe intensities). The microarray data were found in Gene Expression Omnibus (GEO) database GEO accession numbers [GEO:GSE10780] [16].