Ethnic differences in expression of the dysregulated proteins in uterine leiomyomata

Black ethnicity is one of the risk factors for uterine leiomyomata (ULM). Little is known about the ethnic differences in leiomyoma-associated gene products in women with uterine leiomyomata.

A total of 120 hysterectomies with ULM were collected from black, Asian, Hispanic and white women (30 cases from each group). Twenty-two gene products were selected for the study. The expressions of the selected dysregulated gene products were measured by the semiquantification and the immunoscores were normalized by matched myometrium.

The relative expressions of progesterone receptor A (PR-A) (up-regulation), retinoid acid receptor alpha (down-regulation), and retinoid X receptor alpha (RXRalpha) (no change) in leiomyomata compared to normal myometrium in black women were significantly different compared to other ethnic groups (P < 0.05). About one-third of ULM from black women subclustered together in association with a group of up-regulated gene products. Many other gene products, including local growth factors, insulin-like growth factor (IGF)-signalling proteins, and cell proliferation markers, were dysregulated in ULM but showed non-significant differences between the ethnic groups.

There are substantial differences of the sex steroid receptors and other nuclear receptors between black women and other ethnic groups. Based on tissue microarray data, there are at least two broad groups of leiomyomata presented by the dysregulation of different groups of gene products. One is dominated by up-regulation of amplified in breast cancer 1, CD24, hamartin, human mobility group gene 2, IGF2, PR-A and RXR, and the other is characterized by up-regulation of epithelial growth factor receptor, down-regulation of hamartin, PR-A and tuberin.