Trichorhinophalangeal Syndrome-1 Research Articles

Expression of TRPS1 in Metastatic Tumors of the Skin: An Immunohistochemical Study of 72 Cases

TRPS1 (Tricho-rhino-phalangeal syndrome 1) is a GATA transcriptional activator gene encoding for a protein used as a sensitive immunohistochemical marker of breast carcinomas. In dermatopathology, TRPS1 is used as a marker of mammary and extramammary Paget’s disease and is also expressed by a variety of primary cutaneous tumors, mostly of adnexal origin. So far, very limited data exist on the expression of TRPS1 in metastatic skin tumors. We studied the immunohistochemical expression of TRPS1 in 72 cutaneous metastatic tumors from the breast (n: 19) and other origins (n: 53) in order to assess its diagnostic usefulness. The intensity of TRPS1 immunostaining was expressed as a histoscore: the product of the percentage of positive cells (scored semi-quantitatively 0–4) and the staining intensity (scored 0–3). In normal skin, nuclear TRPS1 expression was predominantly observed in cells of adnexal structures (pilosebaceous follicles and sweat glands). Eighteen (18/19, 94.7%) metastatic breast carcinomas showed diffuse and strong TRPS1 positivity (histoscore 12). Lower reactivity was found in some other metastases, including from the lung (11/22), the female genital tract (3/4), and the kidney (2/4), whereas most (20/22) metastases from the digestive system and peritoneum, along with a case of metastatic prostate carcinoma, were negative. These results suggest that a high histoscore for TRPS1 is in favor of the mammary origin of metastatic cutaneous carcinoma. Although TRPS1 is not absolutely specific or sensitive to a particular primary, we consider that it can be added to a panel of other markers when investigating the origin of a cutaneous metastasis, namely when this is the first manifestation of the neoplastic disease.

Trichorhinophalangeal syndrome 1 expression in breast and nonbreast metastases from Müllerian, lung, gastrointestinal tract, and pancreatic primary tumors by immunohistochemistry with cytology cell block specimens.

Trichorhinophalangeal syndrome 1 (TRPS1) expression in primary breast and other solid tumors has been investigated but its role as a marker in metastatic tumors is unclear. The objective of this study was to evaluate the sensitivity and specificity of TRPS1 as a breast cancer immunomarker in metastatic tumors that originated from breast, Müllerian, lung, gastrointestinal (GI), and pancreatic primary tumors with cell blocks from fine-needle aspiration (FNA) and effusion specimens. Cell blocks were immunostained with anti-TRPS1 monoclonal antibody (clone EPR16171). Histochemical scores (H scores) (proportion × intensity; range, 0-300) were assigned; H scores of ≥10 were considered positive. Overall, 160 specimens were examined, including 127 FNAs (35 breast, 25 Müllerian, 36 lung, and 31 GI and pancreatic carcinomas) and 33 effusion specimens (18 breast, 12 Müllerian, one lung, and two GI carcinomas). TRPS1 was positive in 51 of 53 (96%) metastatic breast carcinomas and in 28 of 107 (26.2%) nonbreast metastatic tumors. Metastatic breast carcinoma showed the highest mean H score of 247.35, compared to 45.36 in Müllerian, 8.4 in lung, and 5.88 in GI tumors. The sensitivity and specificity of TRPS1 for identifying a breast origin in metastatic tumors was 96.22% and 72.89%, respectively. Despite high overall sensitivity, TRPS1 showed lower specificity as a breast immunomarker because of its expression in nonbreast tumors. The mean H score in nonbreast tumors was significantly lower than in metastatic breast tumors. It is important to recognize the broad range of expression of TRPS1 in metastatic breast and nonbreast tumors to avoid an incorrect determination of a metastatic tumor's organ of origin.

TRPS1 is a Highly Sensitive Marker for Breast Cancer: A Tissue Microarray Study Evaluating More Than 19,000 Tumors From 152 Different Tumor Entities.

Trichorhinophalangeal syndrome 1 (TRPS1) is a nuclear protein highly expressed in breast epithelial cells. TRPS1 immunohistochemistry (IHC) has been suggested as a breast cancer marker. To determine the diagnostic and prognostic utility of TRPS1 IHC, tissue microarrays containing 19,201 samples from 152 different tumor types and subtypes were analyzed. GATA3 IHC was performed in a previous study. TRPS1 staining was seen in 86 of 152 tumor categories with 36 containing at least one strongly positive case. TRPS1 staining predominated in various types of breast carcinomas (51%-100%), soft tissue tumors (up to 100%), salivary gland tumors (up to 46%), squamous cell carcinomas (up to 35%), and gynecological cancers (up to 40%). TRPS1 positivity occurred in 1.8% of 1083 urothelial neoplasms. In invasive breast carcinoma of no special type, low TRPS1 expression was linked to high grade ( P = 0.0547), high pT ( P < 0.0001), nodal metastasis ( P = 0.0571), loss of estrogen receptor and progesterone receptor expression ( P < 0.0001 each), and triple-negative status ( P < 0.0001) but was unrelated to patient survival ( P = 0.8016). In squamous cell carcinomas from 11 different sites, low TRPS1 expression was unrelated to tumor phenotype. Positivity for both TRPS1 and GATA3 occurred in 47.4% to 100% of breast cancers, up to 30% of salivary gland tumors, and 29 (0.3%) of 9835 tumors from 134 other cancer entities. TRPS1 IHC has high utility for the identification of cancers of breast (or salivary gland) origin, especially in combination with GATA3. The virtual absence of TRPS1 positivity in urothelial neoplasms is useful for the distinction of GATA3-positive urothelial carcinoma from breast cancer.

TRPS1 is a promising marker for all subtypes of breast cancer.

Trichorhinophalangeal syndrome-1 (TRPS1) has been proposed as a novel breast marker with equally high expression in breast cancer (BC) subtypes, making it a useful diagnostic tool. Here, its expression was evaluated alongside other commonly used markers [GATA3, GCDFP15, mammaglobin (MGB) and SOX10] in a large cohort of BCs (n = 1852) and their corresponding nodal metastases. Its usefulness as a diagnostic tool and its correlation with clinicopathological features were assessed. TRPS1 was expressed at 75.8% overall in the BC cohort, with at least 58% expression among BC subtypes. It was less sensitive than GATA3 for luminal and HER2-overexpressing (HER2-OE) cancers (luminal A: 82 versus 97%; luminal B: 80 versus 95%; HER2-OE: 62 versus 76%), but it was the most sensitive for TNBC (60 versus ≤ 41%). It showed a stable expression in nodal metastases (primary tumour 76 versus nodal metastasis 78%), unlike a reduced nodal expression for GATA3 (86 versus 77%). TRPS1 outperformed GATA3 in detecting non-luminal cancers whenpaired with other breast markers. TRPS1 and GCDFP15 was the most sensitive combination in TNBC detection, with a 76% detection rate. For TRPS1-negative and GCDFP15-negative TNBCs, SOX10 was more sensitive than GATA3 (29 versus 24%). TRPS1 is a highly sensitive marker for all breast cancer subtypes, outperforming GATA3 in non-luminal cancers and displaying the highest sensitivity for TNBC detection when combined with GCDFP15. It is a valuable addition to the breast marker panel for accurate identification of BC.

MicroRNA-206-3p suppresses hepatic lipogenesis and cholesterol synthesis while driving cholesterol efflux.

Hepatosteatosis, hypertriglyceridemia, and hypertriglyceridemia are interconnected metabolic disorders. This study is designed to characterize how microRNA-206-3p (miR-206) simultaneously prevents de novo lipogenesis (DNL), cholesterol synthesis, and VLDL production in hepatocytes while promoting cholesterol efflux in macrophages. MiR-206 levels were reduced in hepatocytes and macrophages of mice subjected to a high-fat, high-cholesterol diet (HFHC). A negative feedback between LXRα (liver X receptor) and miR-206 is formed to maintain high LXRα and low miR-206 in hepatocytes. Systemic administration of miR-206 alleviated hepatosteatosis, hypertriglyceridemia and hypercholesterolemia in mice. A significant reduction in LDL-cholesterol and VLDL-cholesterol but unaltered HDL-cholesterol was observed in miR-206-treated mice. Mirroring these findings, miR-206 reprogrammed the transcriptome of hepatocytes towards inhibition of DNL, cholesterol synthesis, and assembly and secretion of VLDL. In macrophages, miR-206 activated expression of genes regulating cholesterol efflux. Hepatocyte-specific expression of miR-206 reduced hepatic and circulating triglycerides and cholesterol as well as VLDL production, while transplantation of macrophages bearing miR-206 facilitated cholesterol efflux. Mechanistically, miR-206 directly targeted Lxrα and Hmgcr in hepatocytes but facilitated expression of Lxrα in macrophages by targeting macrophage-specific TRPS1 (tricho-rhino-phalangeal syndrome 1), a transcription repressor of Lxrα. By targeting Hmgcr and Lxrα, miR-206 inhibited DNL, VLDL production and cholesterol synthesis in hepatocytes, whereas it drove cholesterol efflux by activating the TRPS1-LXRα axis. MiR-206, through differentially modulating LXRα signaling in hepatocytes and macrophages, inhibits DNL, promotes cholesterol efflux, and concurrently hinders cholesterol synthesis and VLDL production. MiR-206 simulates the functions of lipid-lowering medications, statins and LXRα agonists.

TRPS1, a New Promising Marker for Assessment of Distant Metastatic Breast Cancer.

This article reviewed the identification of breast cancer in the distant metastatic setting through traditional immunohistochemical markers, such as mammaglobin and GATA3, compared with the novel immunohistochemical stain, Trichorhinophalangeal syndrome-1 (TRPS1). We review previous studies evaluating TRPS1 staining, which were conducted using cytology specimens, as well as our recently conducted study evaluating this stain using surgical tissue samples, both from primary and distant metastatic invasive breast carcinoma. In summary, although no immunohistochemical stain is 100% specific or sensitive, in the metastatic setting where tissue available for ancillary studies is limited, TRPS1 was a reliable and even a standalone marker for breast origin, particularly in cases of triple-negative breast cancer.

Trps1 acts as a regulator of Sf-1 transcription and testosterone synthesis in mouse Leydig cells.

Infertility has attracted global concern, and disruption of testosterone is a common cause of male infertility. Exploring the critical factors in testosterone biosynthesis may provide new insights for disease research and clinical therapy. Research on trichorhinophalangeal syndrome-1 (Trps1) gene has recently been focus on cancers; it is yet unknown whether Trps1 produces a marked effect in the male reproductive system. In the current study, single-cell RNA sequencing analysis of trichorhinophalangeal syndrome-1 gene (Trps1) expression in mouse testes and cleavage under targets and tagmentation and RNA sequencing were utilized to investigate the functionality of Trps1 in mouse Leydig cells. Knockdown of Trps1 increased testosterone synthesis in vitro and vivo using adeno-associated viral delivery and conditional knockout models. The results showed that Trps1 was abundantly expressed in Leydig cells. The expression levels of both steroidogenic factor-1 (Sf-1) and steroidogenic enzymes (Cyp11a1, Hsd3b, Cyp17a1, and Hsd17b3) as well as testosterone secretion were increased after Trps1 deficiency in vivo and vitro. Furthermore, disruption of Trps1 reduced histone deacetylase 1/2 activity and increased histone H3 acetylation in the Sf-1 promoter, thereby promoting testosterone secretion. Interestingly, Sf-1 also regulated the transcription of Trps1 through activating transcription factor 2. These results indicate that Trps1 targets Sf-1 to affect steroidogenesis through histone acetylation and shed light on the critical role of Trps1 functioning in the mouse Leydig cells.

Paclitaxel Resistance Modulated by the Interaction between TRPS1 and AF178030.2 in Triple-Negative Breast Cancer.

Paclitaxel is a chemotherapeutic agent that acts as an inhibitor of cellular mitosis and has been widely used in the treatment of triple-negative breast cancer (TNBC). However, paclitaxel resistance is one of the major reasons that contribute to the high failure rates of chemotherapy and the relapse of TNBC. Accumulating studies have demonstrated that long noncoding RNA (lncRNA) plays a role in the paclitaxel resistance and positively correlated with progression and metastasis of breast cancers. In the present study, microarray expression profile analysis of lncRNA was performed between paclitaxel-resistant TNBC cell line MDA-MB-231 and their parental cells. After verification with quantitative PCR, we identified that AF178030.2, an orphan lncRNA, was significantly upregulated in paclitaxel-resistant TNBC cells. Overexpression of AF178030.2 greatly attenuated the sensitivity of TNBC to paclitaxel, whereas knockdown of AF178030.2 enhanced the sensitivity of TNBC cells to paclitaxel. Furthermore, bioinformatic analysis and RNA binding protein immunoprecipitation assay reveal that AF178030.2 can directly bind with trichorhinophalangeal syndrome-1 (TRPS1), an oncogene in breast cancer, and downregulate its expression in paclitaxel-resistant TNBC cells. TRPS1 overexpression effectively increased the sensitivity of paclitaxel-resistant TNBC cells to paclitaxel. Taking together, high AF178030.2 expression contributed to paclitaxel resistance in TNBC through TRPS1 and poor clinical outcomes, which may provide a new treatment strategy for paclitaxel-resistant TNBC patients.

TRPS1 and YAP1 Regulate Cell Proliferation and Drug Resistance of Osteosarcoma via Competitively Binding to the Target of circTADA2A - miR-129-5p.

IntroductionThe yes-associated protein (YAP) and trichorhinophalangeal syndrome 1 (TRPS1) have been reported to account for the pathogenesis of cancers and may play an important role in osteosarcoma (OS). This study intended to investigate the modulatory effect and relationship of TRPS1 and YAP1 in OS cells.MethodsThe expression difference of YAP1 and TRPS1 in OS cells was measured. Then, the effect of circTADA2A silence on YAP1 and TRPS1 expression as well as OS proliferation and drug resistance was estimated.ResultsTRPS1 and YAP1 were upregulated in OS cell lines, and TRPS1 and YAP1 were highly expressed in MG63 and U2OS cells, respectively. The cell proliferation of MG63 was lower than that of U2OS, but the opposite result was observed in the presence of cisplatin (DDP). CircTADA2A was upregulated while miR-129-5p was downregulated in MG63 and U2OS cells compared. Besides, circTADA2A knockdown inhibited cell proliferation and reduced DDP resistance in both MG63 and U2OS. MiR-129-5p was increased but TRPS1 and YAP1 were decreased by circTADA2A knockdown. Meanwhile, circTADA2A knockdown reduced TRPS1 protein expression but enhanced phosphorylated (p)-YAP1. In xenograft OS tumor mice, circTADA2A knockdown inhibited tumor growth in the absence or presence of DDP. Finally, miR-129-5p could bind to circTADA2A, TRPS1 and YAPS.DiscussionCircRNA TADA2A could target miR-129-5p, which was competitively bound by TRPS1 and YAP1, thereby regulating OS cell proliferation and drug resistance.

LncRNA PVT1 Regulates TRPS1 Expression in Breast Cancer by Sponging miR-543.

BackgroundBreast cancer is the most common female malignancy with high invasion and metastasis abilities. Studies have shown that long non-coding RNA (lncRNA) plasmacytoma variant translocation 1 gene (PVT1) is an oncogene and is positively correlated with progression and metastasis of breast tumors. However, the detailed mechanism of PVT1 in breast cancer tumorigenesis is not fully understood.MethodsReal-time polymerase quantitative chain reaction (RT-qPCR) was performed to identify the expression levels of PVT1, miR-543 and trichorhinophalangeal syndrome-1 gene (TRPS1) in breast cancer tissues and cells. Cell proliferation was measured by plate clone formation and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazol-3-ium bromide (MTT) assay. Apoptosis and motility of MCF-7 and MDA-MB-436 cells were assessed with flow cytometry assay and transwell migration and invasion analyses, respectively. In addition, a model was established to probe the function of PVT1 silencing in vivo. The target relationship among PVT1, miR-543 or TRPS1 was confirmed by dual-luciferase reporter analysis, RNA immunoprecipitation (RIP) and RNA pull down assays. The protein expression level of TRPS1 was evaluated with Western blot assay.ResultsPVT1 expression was upregulated in breast cancer tissues and cell lines. In addition, PVT1 silencing inhibited breast cancer cell growth and motility, while increased apoptosis. Meanwhile, the effects of PVT1 or miR-543 could be reversed by introducing overexpressed plasmid of miR-543 or TRPS1 in breast cancer cell lines, respectively.ConclusionKnockdown of PVT1 repressed breast cancer cell growth and motility, and induced apoptosis in vitro and reduced tumor volume and weight in vivo. Mechanically, the overexpression of PVT1 enhanced TRPS1 level by negatively targeted miR-543 in breast cancer.

Atypical GATA protein TRPS1 plays indispensable roles in mouse two-cell embryo

ABSTRACT Zygotic genome activation (ZGA) is one of the most critical events at the beginning of mammalian preimplantation embryo development (PED). The mechanisms underlying mouse ZGA remain unclear although it has been widely studied. In the present study, we identified that tricho-rhino-phalangeal syndrome 1 (TRPS1), an atypical GATA family member, is an important factor for ZGA in mouse PED. We found that the Trps1 mRNA level peaked at the one-cell stage while TRPS1 protein did so at the two/four-cell stage. Knockdown of Trps1 by the microinjection of Trps1 siRNA reduced the developmental rate of mouse preimplantation embryos by approximately 30%, and increased the expression of ZGA marker genes MuERV-L and Zscan4d via suppressing the expression of major histone markers H3K4me3 and H3K27me3. Furthermore, Trps1 knockdown decreased the expression of Sox2 but increased Oct4 expression. We conclude that TRPS1 may be indispensable for zygotic genome activation during mouse PED.

Loss of Tricho-Rhino-Phalangeal Syndrome-1 (TRPS1) expression as a Biomarker of Poor Prognosis in Patients with Gastric Cancer

Loss of Tricho-Rhino-Phalangeal Syndrome-1 (TRPS1) expression as a Biomarker of Poor Prognosis in Patients with Gastric Cancer

Nuclear cathepsin D enhances TRPS1 transcriptional repressor function to regulate cell cycle progression and transformation in human breast cancer cells.

The lysosomal protease cathepsin D (Cath-D) is overproduced in breast cancer cells (BCC) and supports tumor growth and metastasis formation. Here, we describe the mechanism whereby Cath-D is accumulated in the nucleus of ERα-positive (ER+) BCC. We identified TRPS1 (tricho-rhino-phalangeal-syndrome 1), a repressor of GATA-mediated transcription, and BAT3 (Scythe/BAG6), a nucleo-cytoplasmic shuttling chaperone protein, as new Cath-D-interacting nuclear proteins. Cath-D binds to BAT3 in ER+ BCC and they partially co-localize at the surface of lysosomes and in the nucleus. BAT3 silencing inhibits Cath-D accumulation in the nucleus, indicating that Cath-D nuclear targeting is controlled by BAT3. Fully mature Cath-D also binds to full-length TRPS1 and they co-localize in the nucleus of ER+ BCC where they are associated with chromatin. Using the LexA-VP16 fusion co-activator reporter assay, we then show that Cath-D acts as a transcriptional repressor, independently of its catalytic activity. Moreover, microarray analysis of BCC in which Cath-D and/or TRPS1 expression were silenced indicated that Cath-D enhances TRPS1-mediated repression of several TRPS1-regulated genes implicated in carcinogenesis, including PTHrP, a canonical TRPS1 gene target. In addition, co-silencing of TRPS1 and Cath-D in BCC affects the transcription of cell cycle, proliferation and transformation genes, and impairs cell cycle progression and soft agar colony formation. These findings indicate that Cath-D acts as a nuclear transcriptional cofactor of TRPS1 to regulate ER+ BCC proliferation and transformation in a non-proteolytic manner.

Prognostic value of the trichorhinophalangeal syndrome-1 (TRPS-1), a GATA family transcription factor, in early-stage breast cancer

BackgroundTRPS-1 is a new GATA transcription factor that is differentially expressed in breast cancer (BC) where it been found recently to regulate epithelial-to-mesenchymal transition (EMT). Patients and methodsWe carried out a quantitative immunohistochemistry (qIHC) analysis of TRPS-1 expression in 341 primary-stage I–III BC samples in relation to patient clinical characteristics as well as its prognostic value, especially in an estrogen receptor-positive (ER+) subgroup. ResultsHigher TRPS-1 expression was significantly associated with a number of clinical and pathological characteristics as well as with improved overall survival (OS) and disease-free survival (DFS). Among stage I/II ER+ BC patients who received endocrine therapy alone, those with high TRPS-1 expression had significantly longer OS and DFS. There was also a strong association between TRPS-1 levels and the EMT marker E-cadherin in the ER+ invasive ductal carcinoma cases. Analysis of gene expression data on a panel of BC lines found that TRPS-1 expression was low or absent in BC lines having enriched mesenchymal features. ConclusionsOur data indicated that TRPS-1 is an independent prognostic marker in early-stage BC and a new EMT marker that can distinguish patients with ER+ BC who will respond longer to adjuvant endocrine therapy.

Roles of trichorhinophalangeal syndrome-1 gene in normal breast development and breast cancer

GATA transcription factor family members have been found to involve in the growth and differentiation of mammary gland. Among them GATA-3 is regarded as the most critical regulator involving the tumorigenesis of breast cancer (BC). Recently, trichorhinophalangeal syndrome-1 gene (TRPS-1), a new GATA family member, has been identified to be highly prevalent in breast cancer. Compared with ER-negative breast cancer, the expression of TRPS-1 is higher in ER-positive breast cancer and was significantly correlates with estrogen receptor, progesterone receptor, and GATA-3, indicating it may serve as a ductal epithelial cell-specific regulator in the differentiation of breast ductal epithelial cells. Studies have shown that miR221/222 is able to downregulate the expression of an epithelial cell marker E-cadherin by targeting TRPS-1, resulting in mammary epithelial cells transition to mesenchymal cell (EMT). In addition, it has been well accepted that, and the Science and Technology Bureau of Jiaxing (2012AY1071-2)TRPS-1 plays a role in the differentiation of several other cell types including kidney nephric mesenchymal cells, columnar chondrocytes, and osteoclasts, indicating that TRPS-1 involves in mesenchymal-to-epithelial cell transition (MET). In this article, we summarize the roles of GATA transcription factor TRPS-1 in ductal epithelial cells and the roles of its gene and protein expressions in predicting the prognosis of breast cancer.

Increased Expression of TRPS1 Affects Tumor Progression and Correlates with Patients' Prognosis of Colon Cancer

Aim. To detect the expression pattern of tricho-rhino-phalangeal syndrome-1 (TRPS1) in human colon cancer and to analyze its correlation with prognosis of patients with this disease. Methods. The expressions of TRPS1 in human colon cancer and its corresponding noncancerous colon tissues were detected at both mRNA and protein levels. Results. The mRNA and protein expression levels of TRPS1 were both significantly higher in colon cancer than in corresponding noncancerous colon tissues (both P < 0.001). The protein level of TRPS1 in colon cancer tissues was significantly correlated with the mRNA level (r = 0.9, P < 0.001). Additionally, immunohistochemistry analysis also found increased TRPS1 expression in 63.0% (63/100) of colon cancer tissues. High TRPS1 expression was significantly associated with positive lymph node metastasis (P = 0.006) and higher pathological stage (P = 0.008) of patients with colon cancer. Multivariate Cox regression analysis further suggested that the increased expression of TRPS1 was an independent poor prognostic factor for this disease. Conclusion. Our data offer the convincing evidence for the first time that the increased expression of TRPS1 may be involved in the pathogenesis and progression of colon cancer. TRPS1 might be a potential marker to predict the prognosis in colon cancer.

Expression and relevance of TRPS-1: a new GATA transcription factor in breast cancer.

GATA transcription factor family members have been found to play a critical role in the differentiation of many tissue types. For example, GATA-3 has been found to be highly correlated with estrogen receptor α (ER) expression and is emerging as one of the "master regulators" in breast ductal epithelial cell differentiation. Recently, we discovered another GATA family member highly prevalent in breast cancer called the trichorhinophalangeal syndrome-1 gene (TRPS-1). Using a quantitative immunohistochemistry (qIHC) approach, we found that TRPS-1 was significantly correlated with ER, PR, GATA-3, as well as HER2 expression. However, TRPS-1 was also found to be expressed in a high proportion of ER(-) ductal epithelial breast cancers (BCs), indicating that it may act as a ductal epithelial cell-specific transcription factor regulating cell fate at some point in the epithelial cell differentiation pathway. In keeping with this hypothesis, we found that TRPS-1 protein expression in BC above a certain threshold using qIHC correlated with markedly improved overall survival. Cox proportional hazards analysis found that both TRPS-1 and ER expression above critical threshold equally predicted for improved survival. Thus, TRPS-1 may be a powerful new positive prognostic marker in BC, and further IHC studies, as well as examination of its molecular function in ductal epithelial cell differentiation in the breast, are warranted. In this regard, data on the role of TRPS-1 in the differentiation of cells from mesenchymal precursors in other tissues, such as kidney metanephric mesenchymal cells, columnar chondrocytes, and osteoblasts, in mouse models may be useful. Indeed, these studies have found that TRPS-1 is a critical regulator of mesenchymal-to-epithelial cell transition. In the mammary gland, the restricted expression of TRPS-1 in human, mouse, and rat ductal epithelial cells suggests that it may also play a similar role during ductal luminal progenitor/stem cell differentiation. We present a model of TRPS-1 action in which it may act upstream of GATA-3 and ER on an earlier ductal epithelial progenitor cell or mammary stem cell during mammary gland development and also helps prevent reversion of ER(+) BC cells back into mesenchymal-like cells. This model predicts that BCs with low or no TRPS-1 expression may inherently be much less differentiated and more aggressive tumors with less favorable prognosis.

Abstract P6-08-14: TRPS-1, a New GATA Family Transcription Factor, Regulates Epithelial-Mesenchymal Transition and Maintains an Estrogen Responsive, Claudin-Positive Phenotype in Breast Cancer Cells

Abstract We recently reported that TRPS-1 (Trichorhinophalangeal Syndrome-1), a new GATA family transcription factor, is a ductal epithelial cell-specific gene expressed in normal breast and over-expressed in the majority of human breast cancer (BC), especially in ER+ BC. We also found that TRPS-1 is a marker for better prognosis when expressed over a critical threshold level using a new quantitative IHC method applied to over 150 primary BC cases of all subtypes. Here, we studied the molecular function of TRPS-1 using a lentiviral shRNA knockdown approach in an ER+ ductal epithelial BC cell line (T47D; luminal B type) normally expressing high levels of TRPS-1. Strikingly, knockdown of TRPS-1 in T47D cells resulted in a complete loss of epithelial markers, including E-cadherin and CK8/18 protein together with the loss of ER and a host of ER-associated genes, such as GATA-3 and FOXA1. In contrast, N-cadherin, vimentin, slug, and other genes associated with a mesenchymal phenotype were induced. Gene expression profiling using microarray found a number of additional differentially expressed genes following TRPS-1 knockdown, including a large decrease in the Prolactin receptor (PRLR), Claudin-1 and 6, EpCAM, PGR, and CD24, while AKT3 and MET (HGF-R) were increased. The Claudin-1 and PRLR gene were down-modulated 149-fold and 167-fold, respectively. This was verified at the protein level, with a total loss of cell surface Claudin-1 and PRLR expression in the TRPS-1 knockdown cells. Overall, the gene expression profile of TRPS-1 knockdown T47D cells resembled the recently described “Claudin-low” BC subset. TRPS-1 knockdown also had dramatic functional consequences, with the cells acquiring a mesenchymal, spindle-like morphology and high resistance to growth arrest and apoptosis under conditions of serum and estrogen deprivation. Moreover, these cells formed aggressive tumors in nude mice in an estrogen-independent manner after orthotopic injection into mammary fat pads, while control cells produced only small non-palpable tumors. In addition, transient induction of TRPS-1 expression in ER/TRPS-1-negative MDA-MB-231 cells led to a significant expression of ER together with other ER-associated genes. Our data suggests that TRPS-1 is a critical new GATA family transcription factor in the mammary gland that is at the hub of a cell lineage-determination pathway regulating epithelial-mesenchymal transition. In BC it may function in maintaining a more highly differentiated and less aggressive Claudin-positive ductal epithelial phenotype. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P6-08-14.

Abstract P3-10-41: Quantitative Immunohistochemical Analysis and Prognostic Significance of TRPS-1, a New GATA Transcription Factor Family Member, in Breast Cancer

Abstract The Trichorhinophalangeal Syndrome-1 gene (TRPS-1) is a novel GATA transcription factor family member expressed in &amp;gt;90% of human breast cancers. In this study, we developed a new quantitative IHC (qIHC) method to study TRPS-1 as a possible indicator ofprognosis in BC. Using this method, a quantitative parameter for TRPS-1 expression called a Quick Score (QS) was derived from the measured Labeling Index (LI) and Mean Optical Density (MOD) after IHC and applied to a set of 152 Stage II/III BC patients from 1993-2006 who did not receive preoperative chemotherapy. Although highly prevalent in BC, a wide range of TRPS-1 QS was found among the sample set with higher TRPS-1 QS significantly associated with tumor ER-alpha (p= 0.023 for QS, and p= 0.028 for Allred score), PR (p= 0.009), GATA-3 (P&amp;lt;0.0001), and E-cadherin (p&amp;lt; 0.001). TRPS-1 QS was also positively associated with HER2 status (p=0.026). Analysis of different ductal structures revealed that TRPS-1 was expressed at low levels in normal ducts and in usual ductal hyperplasia, but showed a marked increase in DCIS and invasive carcinoma lesions. An analysis of TRPS-1 expression in association with overall survival revealed that TRPS-1 QS (≥4.0) was significantly associated with improved survival (p=0.0165). Patients with TRPS-1 QS &amp;lt;4 had a hazard ratio of 2 (p=0.019) after univariate Cox proportional hazards analysis. Further analysis of the patient samples revealed an ER-/lo, HER2+ (amplified) BC subset in which TRPS-1 expression above a critical quantitative threshold was predictive of greatly improved survival (median survival not reached after 10 years), while patients in this subset with TRPS-1 expression below this threshold having a median survival of less than 5 years. In summary, this new qIHC approach revealed critical differences in TRPS-1 expression in primary BC samples and found that this new GATA family member may be a promising positive prognostic marker that may regulate BC progression. In addition, TRPS-1 may also be a relevant new marker in a luminal ER-/low, HER2+ BC subset. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-10-41.

Quantitative immunohistochemical analysis and prognostic significance of TRPS-1, a new GATA transcription factor family member, in breast cancer.

The trichorhinophalangeal syndrome 1 (TRPS-1) gene is a novel GATA transcription factor family member. Previously, using a gene expression profiling and immunohistochemistry (IHC) screen, we identified TRPS-1 as a highly prevalent gene in breast cancer (BC), expressed in >90% of estrogen receptor alpha (ERα)(+) and ERα(-) BC subtypes. TRPS-1 was also shown to be expressed in prostate cancer where it was shown to play a proapoptotic function during androgen withdrawal possibly through regulating antioxidant metabolism. The role of TRPS-1 and its prognostic significance in hormone-dependent and hormone-independent BC however is not known. In this study, we developed a new quantitative IHC (qIHC) method to further study TRPS-1 as a marker and possible prognostic indicator in BC. By using this method, a quantitative parameter for TRPS-1 expression called a quick score (QS) was derived from the measured labeling index and mean optical density after IHC and applied to a set of 152 stage II/III BC patients from 1993 to 2006 who did not receive preoperative chemotherapy. Associations between QS and tumor characteristics were evaluated using the Kruskal-Wallis test. A wide range of TRPS-1 QS was found among the sample set with higher TRPS-1 QS significantly associated with tumor ERα (p = 0.023 for QS and p = 0.028 for Allred score), progesterone receptor (p = 0.009), and GATA-3 (p < 0.0001). TRPS-1 QS was also positively associated with HER2 status (p = 0.026). Further analysis of different ductal structures in ten BC cases revealed that TRPS-1 expression was expressed at low levels in the remaining normal ducts and in areas of usual ductal hyperplasia but showed marked increase in expression in ductal carcinoma in situ and invasive carcinoma lesions in the tissue. An analysis of TRPS-1 expression in association with overall survival in the 152 stage II/III sample set also revealed that TRPS-1 QS (≥4.0) was significantly associated with improved survival (p = 0.0165). Patients with TRPS-1 QS <4 had a hazard ratio of 2 (p = 0.019) after univariate Cox proportional hazards analysis. In summary, this new qIHC approach was found to reveal critical differences in TRPS-1 expression in primary BC samples and found that it is a promising prognostic marker that should be further evaluated as a possible tumor suppressor gene facilitating improved survival in different subtypes of BC.