Identification ofNTN4, TRA1, andSTC2as Prognostic Markers in Breast Cancer in a Screen for Signal Sequence Encoding Proteins

Abstract

Purpose: In a previous screen using a signal-trap library, we identified a number of secreted proteins up-regulated in primary tumor cells isolated from invasive breast cancers.The purpose of this study was to assess the expression of these genes in human invasive breast tumors and to determine the significance of their expression for prognosis in breast cancer. Experimental Design: A tissue microarray containing 245 invasive breast tumors from women treated with curative surgery followed by anthracycline-based chemotherapy and hormone therapy for the estrogen receptor (ER)^positive tumors was screened by in situ hybridization with probes against thrombospondin 3 (TSP3), insulin-like growth factor binding protein 7 (IGFBP7), tumor rejection antigen 1 (TRA1), stanniocalcin 2 (STC2), and netrin 4 (NTN4). Correlations between categorical variables were done using the m 2 test and Fisher's exact test. Cumulative survival probabilities were calculated using the Kaplan-Meier method and multivariate survival analysis was done with Cox hazard model. A series of breast cancers were also stained with NTN4 antibodies. Results: All five genes examined were expressed in invasive breast tumor cells. NTN4 protein expression was also confirmed by immunohistochemistry.Together, these data validate the design and screening of the signal-trap library. Univariate survival analysis revealed that expressions of TRA1, STC2, and NTN4 are correlated with longer disease-free survival and thatTRA1 and NTN4 are associated with longer overall survival. Multivariate analysis showed that NTN4 is an independent prognostic factor of overall survival. Conclusions:This article describes the identification of three secreted proteins, NTN4,TRA1, and STC2, as potential novel prognostic markers in breast cancer.Paracrine signaling from tumor cell to stromal cells plays a key role in regulating leukocyte recruitment, angiogenesis, and activation of stromal fibroblasts. This, in turn, changes the tumor environment, thus regulating tumor cell proliferation, survival, migration, and invasion (1 -4). As a consequence, identifying secreted proteins that are up-regulated in tumor cells is critical for understanding these complex signaling interactions and identifying key targets for therapeutic intervention. We have previously described the generation and screening of a library to preferentially identify genes overexpressed in invasive breast tumor cells (5). The screen was designed to (a) specifically enrich for transcripts that are expressed by primary tumor cells in vivo rather than by cancer cell lines or total tumor tissue in vivo, and (b) to select for transcripts bearing a functional signal sequence and thereby specifically identify overexpressed transmembrane and secreted proteins. The purpose of the current study was to verify that the overexpressed genes that encode for secreted proteins are specifically expressed by breast tumor cells and to determine their prognostic significance in a large cohort of breast cancer patients. The advent o...

Clinicopathological significance of stanniocalcin 2 gene expression in colorectal cancer

“…It was reported that the STC1 gene is associated with some cancers. [17][18][19][20][21][22][23][24] STC2 was reported to be associated with breast cancer, [25][26][27][28][29] ovarian cancer 30 and renal cell carcinoma. 31 However, the relationship between STC2 expression and clinicopathological factors in colorectal cancer has not yet been investigated.…”

A Comparative study of clinicopathological significance, BIRC7, and STC2 expression between squamous cell/adenosquamous carcinomas and adenocarcinoma of gallbladder

“…Some Studies on STC2 gene expression relating to cancer been reported. In breast cancer, STC2 expression was found to be associated with tumor estrogen receptor (ER) status, high STC2 expression was associated with good prognosis in ER-posive breast cancer patients [39] . But it was reported that a significant high expression levels of STC2 in metastatic cases in 5 to 10 years postoperation compared with no-metastastic ones after 10 year postoperation [40] .We examined the relationships between STC2 expression and clinicopathological factors in both SC/ASC and AC of gallbladder, the overexpression of STC2 was associated with large tumor size, high TNM stage, lymph node metastasis, invasion and poor survival.…”

Evaluation of protein expression pattern of stanniocalcin 2, insulin-like growth factor-binding protein 7, inhibin beta A and four and a half LIM domains 1 in esophageal squamous cell carcinoma

“…It is known to have important roles in many physiological processes including bone development, reproduction, wound healing, angiogenesis, and modulation of inflammatory response. Elevated expression of STC2 has been reported in various cancers including renal cell carcinoma [8], breast cancer [9], gastric cancer [10], prostate cancer [11] and neuroblastoma [12]. In addition, Kita et al, have reported STC2 as a predictive marker for lymph node metastasis in ES-CC based on mRNA measurements in 70 clinical samples [13].…”

“…STC2 is reported to be a target gene of HIF-1 transcription factor and is known to promote cell proliferation in hypoxic conditions [14]. STC2 was also found to promote epithelial-mesenchymal transition (EMT) and invasiveness in hypoxic human ovarian cancer cells [9]. STC1, a related gene had also been recently reported to be overexpressed in ESCC [5].…”