Significantly upregulated TACSTD2 and Cyclin D1 correlate with poor prognosis of invasive ductal breast cancer

https://doi.org/10.1016/j.yexmp.2012.08.004Get rights and content

Abstract

The tumor-associated calcium signal transducer 2 (TACSTD2) gene has been reported to be highly expressed in many types of human epithelial cancers, and is associated with tumor metastasis and poor prognosis. The aims of the present investigation were to analyze the TACSTD2 and Cyclin D1 expression at the mRNA and protein levels and to assess its prognostic significance in invasive ductal breast cancer (IDC). The expressions of TACSTD2 and Cyclin D1 in IDC tissues were consistently higher than those in the tumor-adjacent non-malignant tissues by a one-step real-time polymerase chain reaction and immunohistochemistry (P < 0.001 and P = 0.023, respectively). The statistical analysis of clinicopathologic characteristics and immunohistochemistry by the χ2 test showed that the high expression of TACSTD2 in IDC was correlated to histological grade (P = 0.023), P53 status (P = 0.042), Cyclin D1 status (P < 0.001), lymph node metastasis (P < 0.001), distant metastasis (P = 0.004) and TNM staging (P < 0.001). Kaplan–Meier survival and Cox regression analyses were performed to evaluate the prognosis of IDC. These analyses also showed that a high TACSTD2 expression (P = 0.003), a high Cyclin D1 expression (P = 0.041), and lymph node metastasis (P = 0.006) were independent prognosis factors. Collectively, our studies demonstrated that the high expression of TACSTD2 correlates with a poor prognosis in IDC.

Graphical abstract

Highlights

► The prognostic potential of TACSTD2 and Cyclin D1 was evaluated in IDC. ► High expression of TACSTD2 in IDC was related to Cyclin D1 status. ► TACSTD2, Cyclin D1 and lymph node metastasis were independent prognosis factors. ► TACSTD2 and Cyclin D1 correlate with lymph node metastasis and poor overall survival.

Introduction

Breast cancer is one of the most common neoplasms, accounting for approximately one quarter of all cancers in females (Coughlin and Ekwueme, 2009, Fattaneh et al., 2003). It is estimated that more than 1 million women are newly diagnosed every year, and more than 410,000 will die from this cancer worldwide (Coughlin and Ekwueme, 2009). China's urban cancer registries have documented that the incidence of breast cancer has increased 20% to 30% in the past decade (Porter, 2008). Early diagnosis and advances in therapy have begun to reduce mortality in several countries (Coughlin and Ekwueme, 2009, Fattaneh et al., 2003). Tumor markers could significantly alter the type of adjuvant treatment a patient receives and potentially impact the clinical outcome (Khoury et al., 2009). However, such information is not usually available and prognosis factors are needed to identify which patients might benefit from surgery, adjuvant systemic therapy, and/or other treatments (Baak et al., 2009). Since most of the currently available chemotherapeutic agents lack the ability to selectively target cancer cells, it is necessary to find more biological markers for predicting prognosis and molecular-targeted therapies in breast cancer (Fernández et al., 2010, Milacic and Dou, 2009, Schlotter et al., 2008).

Tumor-associated calcium signal transducer 2 (TACSTD2), also known as epithelial glycoprotein 1 (EGP1), as well as cell-surface glycoprotein Trop2 (Trop-2), membrane component chromosome 1 surface marker 1 (M1S1), and gastrointestinal tumor-associated antigen GA733-1 all belong to the tumor-associated calcium signal transducer (TACSTD) gene family (Basu et al., 1995, Calabrese et al., 2001, Fornaro et al., 1995, Linnenbach et al., 1989, Linnenbach et al., 1993, Ripani et al., 1998). TACSTD2 is identified as a single-copy gene in human cells, mapped to chromosome 1p32 by in situ hybridization (Calabrese et al., 2001, Linnenbach et al., 1989). It hybridizes to a single 1.8-kb mRNA from expressing sources and encodes a 35,709 Da type-1 transmembrane protein with a single transmembrane domain (Linnenbach et al., 1993). As a cell-surface glycoprotein first characterized on a human trophoblast cell, TACSTD2 may play a role in regulating the growth of carcinoma cells (Fornaro et al., 1995, Lipinski et al., 1981, Miotti et al., 1987). Nevertheless, its function has not yet been determined.

Recently, TACSTD2 has been reported to be highly expressed in various types of human carcinomas but rarely expressed in normal tissues, and also to be associated with tumor metastasis and poor prognosis of the patient (Bignotti et al., 2010, Cubas et al., 2009, Fang et al., 2009, Fong et al., 2008a, Fong et al., 2008b, Guerra et al., 2008, Mühlmann et al., 2009, Nakashima et al., 2004, Ohmachi et al., 2006). As no report had shown the correlation between the expression of TACSTD2 and prognosis in breast cancer, we examined the expression levels of TACSTD2 mRNA in a number of IDC tissues, using one-step quantitative real-time PCR.

Cyclin D1, an oncogene that has been linked to a less malignant phenotype, is highly expressed in many breast cancers (Lehn et al., 2010). P53, Ki-67, HER2, estrogen receptor (ER) and progesterone receptor (PR) have been traditionally recognized as poor prognostic factors and play significant roles in the management of patients for therapy (Taneja et al., 2010). We have characterized the expressions of TACSTD2 in IDC and adjacent non-malignant tissues. Furthermore, in this investigation we have elucidated the correlation of high TACSTD2 expression with clinicopathology and prognostic significance.

Section snippets

Tissue samples and patients

A panel of formalin-fixed, paraffin-embedded IDC tissues (n = 82) and tumor-adjacent non-malignant tissues (n = 70) were obtained from patients undergoing surgical therapy at the Affiliated Hospital of Nantong University between 2002 and 2007. Clinical data and relevant information were obtained from patient records. None of the patients had received neoadjuvant chemotherapy, radiation therapy, or immunotherapy before surgery. The tissue microarray (TMA) chips containing 152 cores of IDC and

Measurement of TACSTD2 mRNA and Cyclin D1 mRNA expression in breast tissues by One-step qPCR

Total RNA was extracted from the 15 IDC tissues and subjected to One-step qPCR to determine the expression of TACSTD2 mRNA and Cyclin D1 mRNA. To compare the expression of the mRNA with that of non-malignant tissue, we also investigated samples from the matched tumor adjacent tissues. When normalized to GAPDH, the means of TACSTD2 mRNA in breast cancer and corresponding non-cancerous tissue were 6.42 ± 5.697 and 2.34 ± 1.42 respectively (t = 4.5055, P < 0.001). The TACSTD2 expression averaged 2.74-fold

Discussion

TACSTD2 expression has been reported in various types of malignant neoplasms, including squamous cell carcinoma of the oral cavity (Fong et al., 2008a), esophageal carcinoma (Nakashima et al., 2004), gastric carcinoma (Mühlmann et al., 2009), colorectal cancer (Fang et al., 2009, Ohmachi et al., 2006), pancreatic cancer (Fong et al., 2008b), and ovarian carcinoma (Bignotti et al., 2010). These results indicated that a high expression of TACSTD2 showed prognostic value in those solid tumors.

Conflict of interest statement

The authors declare that there are no conflicts of interest.

Acknowledgments

This investigation was supported by grants from the National Natural Science Foundation of China (81101704), Jiangsu Natural Science Foundation, Nanjing, China (BK2008442), and Nanjing Medical Science and Technique Development Foundation, Nanjing, China (ZKX09015). We wish to thank the Affiliated Hospital of Nantong University for providing samples of patients.

References (44)

  • B.O. Anderson et al.

    Guideline implementation for breast healthcare in low-income and middle-income countries: overview of the Breast Health Global Initiative Global Summit 2007

    Cancer

    (2008)
  • J.P. Baak et al.

    Proliferation is the strongest prognosticator in node-negative breast cancer: significance, error sources, alternatives and comparison with molecular prognostic markers

    Breast Cancer Research and Treatment

    (2009)
  • A. Basu et al.

    The epithelial/carcinoma antigen EGP-1, recognized by monoclonal antibody RS7-3G11, is phosphorylated on serine 303

    International Journal of Cancer

    (1995)
  • G. Calabrese et al.

    Assignment of TACSTD1 (alias TROP1, M4S1) to human chromosome 2p21 and refinement of mapping of TACSTD2 (alias TROP2, M1S1) to human chromosome 1p32 by in situ hybridization

    Cytogenetics and Cell Genetics

    (2001)
  • Y.J. Fang et al.

    Elevated expressions of MMP7, TROP2, and surviving are associated with survival, disease recurrence, and liver metastasis of colon cancer

    International Journal of Colorectal Disease

    (2009)
  • V. Fantl et al.

    Chromosome 11q13 abnormalities in human breast cancer

    Cancer Surveys

    (1993)
  • A. Fattaneh et al.

    Pathology & Genetics of Tumors of the Breast and Female, Genital Organs (WHO of Tumor)

    (2003)
  • D. Fong et al.

    High expression of TROP2 correlates with poor prognosis in pancreatic cancer

    British Journal of Cancer

    (2008)
  • M. Fornaro et al.

    Cloning of the gene encoding Trop-2, a cell-surface glycoprotein expressed by human carcinomas

    International Journal of Cancer

    (1995)
  • S.V. Govindan et al.

    Preclinical therapy of breast cancer with a radioiodinated humanized anti-EGP-1 monoclonal antibody: advantage of a residualising iodine radiolabel

    Breast Cancer Research and Treatment

    (2004)
  • E. Guerra et al.

    A bicistronic CYCLIN D1-TROP2 mRNA chimera demonstrates a novel oncogenic mechanism in human cancer

    Cancer Research

    (2008)
  • H. Huang et al.

    Aberrant expression of novel and previously described cell membrane markers in human breast cancer cell lines and tumors

    Clinical Cancer Research

    (2005)
  • Cited by (78)

    • Antibody-drug conjugates targeting Trop-2: Clinical developments in early breast cancer therapy

      2022, Breast
      Citation Excerpt :

      Trophoblast cell surface antigen 2 (Trop-2), a transmembrane glycoprotein, is expressed in all subtypes of breast cancer, especially in more than 85% of triple-negative breast cancer (TNBC) [1], where its high expression is associated with a poor prognosis [2,3].

    • The European Medicines Agency review of sacituzumab govitecan for the treatment of triple-negative breast cancer

      2022, ESMO Open
      Citation Excerpt :

      The selected method and the single cut-off to determine Trop-2 tumor expression status were not deemed sufficient to determine the benefit in patients with tumors that show only a weak or no Trop-2 expression. This was considered of concern in view of the mechanism of action of SG as targeted therapy and the proportion of ∼20% of patients with TNBC without overexpression of Trop-2 according to literature data.29-31 Further analyses including efficacy by Trop-2 expression quartiles and different low Trop-2 expression cut-offs (determined by different IHC scores) were requested.28

    View all citing articles on Scopus
    1

    These authors contributed equally to this work.

    View full text