Differential expression of alpha 2 macroglobulin in response to dietylstilbestrol and in ovarian carcinomas in chickens

Abstract

BackgroundAlpha 2 macroglobulin (A2M; also known as ovostatin), a homotetrameric protein with four disulfide-linked subunits, has the unique feature of inactivating/inhibiting most known proteases including serine-, threonine-, cysteine-, aspartic- and metalloproteases. In chickens, A2M has been identified and characterized biochemically, but little is known of its functional role(s) in the oviduct, hormonal regulation of expression or its expression in ovarian carcinomas in chickens. Therefore, we investigated estrogen regulation of A2M gene expression during development of the chicken oviduct, and its expression in normal and cancerous ovaries from chickens.MethodsTo determine tissue-specific expression of A2M in chickens, we collected various organs from male and female chickens and performed RT-PCR analyses. To examine A2M gene expression in the oviduct of 1-week-old female chicks that received a subcutaneous implant of 15 mg DES in the abdominal region for 20 days, we performed RT-PCR, qPCR and in situ hybridization analyses using cDNAs from control- (n = 5) and DES-treated oviducts (n = 5), and then each segment of the oviduct from DES-treated chicks. To determine if A2M is a biomarker of ovarian cancer in hens, we collected cancerous (n = 10) ovaries from a total of 136 chickens which had completely stopped egg-laying and performed RT-PCR and in situ hybridization analyses.ResultsWe found that A2M is most abundant in the chicken oviduct, specifically luminal (LE) and glandular epithelia (GE), but it was not detected in any other tissues of either sex. We then determined that DES (dietylstilbestrol, a synthetic nonsteroidal estrogen) increased A2M mRNA only in LE and GE of the oviduct of chicks. Further, expression of A2M was most abundant in GE of endometrioid adenocarcinoma of cancerous, but not normal ovaries of hens.ConclusionsCollectively, results of the present study indicate that A2M is novel estrogen-stimulated gene expressed in LE and GE of the chicken oviduct and may be used for monitoring effects of therapies for ovarian cancer in laying hens.

Differential expression of vitelline membrane outer layer protein 1: Hormonal regulation of expression in the oviduct and in ovarian carcinomas from laying hens

“…Scale bar represents 200 μm (the first and third horizontal panels and sense) and 50 μm (the second horizontal panels). mostly detected at stages III and IV of cancerous ovaries whereas its expression was rarely expressed at stage I of cancerous ovaries in hens in accordance with our previous classification of cancerous ovaries from laying hens (Lim et al, 2011a). Based on our prior research and histological analyses of 10 cancerous ovaries from laying hens, we determined that VMO1 expression was predominantly expressed in endometrioid carcinoma of ovaries from laying hens.…”

Chicken Pleiotrophin: Regulation of Tissue Specific Expression by Estrogen in the Oviduct and Distinct Expression Pattern in the Ovarian Carcinomas

“…We previously reported expression of cysteine protease cathepin B (CTSB), serpin peptidase inhibitor, clade B, member 11 (SERPINB11) and alpha 2 macroglobulin (A2M) in ovarian tissue from hens with ovarian cancer [20], [21], [36]. Based on similarities among these genes in expression patterns and estrogen-mediated regulation in the oviduct, we hypothesized that expression patterns for PTN would differ between normal and cancerous ovarian tissues from hens.…”

In-depth LC-MS/MS analysis of the chicken ovarian cancer proteome reveals conserved and novel differentially regulated proteins in humans

“…The elevated levels of OVOS2 in our previous studies [16, 17] and a recent report on elevated levels of A2M in chicken OVC at the transcript level [64] led us to evaluate the expression levels of all MEROPS I39 protease inhibitors in healthy and neoplastic plasma, ovary, and oviductal tissues. The six members of the MEROPS I39 protease inhibitor family in the chicken clustered on the q-arm of chromosome 1 including A2ML1, A2ML2, A2M, LOC425756, OVOS1 (OVST), and OVOS2 (OVSTL) (Fig.…”