EXPRESSION OF HMGI-C, A MEMBER OF THE HIGH-MOBILITY GROUP PROTEIN FAMILY, IN A SUBSET OF BREAST CANCERS - RELATIONSHIP TO HISTOLOGIC GRADE

The high-mobility-group (HMC) protein gene HMGI-C is apparently involv ed in the genesis of a variety of benign human solid tumors with rearr angements of chromosomal region 12q14-15 affecting the HMGI-C gene. So far, no expression of HMGI-C has been found in adult tissues, and no data are available on the expression of HMGI-C in primary human malign ant tumors of epithelial origin. Therefore, we analysed the HMGI-C exp ression patterns in 44 breast cancer samples and 13 samples of nonmali gnant adjacent tissue by hemi-nested reverse transcriptase-polymerase chain reaction for HMGI-C expression. There was no detectable expressi on of HMGI-C in any nonmalignant adjacent breast tissues analyzed. In contrast, we found expression in 20 of 44 breast cancer samples invest igated. In invasive ductal tumors, expression was noted predominantly in tumors with high histologic grade: 17 of 21 breast cancer samples w ith histologic grade 3 but only three of 16 samples with histologic gr ades 1 or 2 showed expression of HMGI-C. In addition, all seven lobula r breast cancer samples tested did not express HMGI-C. From these resu lts, we concluded that HMGI-C expression may be of pathogenetic or pro gnostic importance in breast cancer. (C) 1997 Wiley-Liss, Inc.