Latent transforming growth factor binding protein 4 (LTBP4) is downregulated in mouse and human DCIS and mammary carcinomas

Transforming growth factor beta (TGF-) is able to inhibit the proliferation of epithelial cells and is involved in the carcinogenesis of mammary tumors. Three latent transforming growth factor- binding proteins (LTBPs) are known to modulate TGF- functions. The current study analyses the expression profiles of LTBP4, its isoforms LTBP1 and LTBP3, and TGF-1, TGF-2, TGF-3, and SMAD2, SMAD3 and SMAD4 in human and murine (WAP-TNP8) DCIS compared to invasive mammary tumors. Additionally mammary malignant (MCF7, Hs578T, MDA-MB361) and non malignant cell lines (Hs578BsT) were analysed. Microarray, q-PCR, immunoblot, immunohistochemistry and immunofluorescence were used. In comparison to non-malignant tissues (n = 5), LTBP4 was downregulated in all human and mouse DCIS (n = 9) and invasive mammary adenocarcinomas (n = 5) that were investigated. We also found decreased expression of bone morphogenic protein 4 (BMP4) and increased expression of its inhibitor gremlin (GREM1). Treatment of the mammary tumor cell line (Hs578T) with recombinant TGF-1 rescued BMP4 and GREM1 expression. We conclude that the lack of LTBP4-mediated targeting in malignant mammary tumor tissues may lead to a possible modification of TGF-1 and BMP bioavailability and function

Current evidence and future perspectives on HuR and breast cancer development, prognosis, and treatment.

This is the Accepted Manuscript version of the following article, "Ioly Kotta-Loizou, et al., “Current Evidence and Future Perspectives on HuR and Breast Cancer Development, Prognosis, and Treatment”, Neoplasia, Vol. 18(11): 674-688, October 2016." The final published version is available at:https://doi.org/10.1016/j.neo.2016.09.002 Copyright © 2016, Elsevier.Hu-antigen R (HuR) is an RNA-binding posttranscriptional regulator that belongs to the Hu/ELAV family. HuR expression levels are modulated by a variety of proteins, microRNAs, chemical compounds, or the microenvironment, and in turn, HuR affects mRNA stability and translation of various genes implicated in breast cancer formation, progression, metastasis, and treatment. The aim of the present review is to critically summarize the role of HuR in breast cancer development and its potential as a prognosticator and a therapeutic target. In this aspect, all the existing English literature concerning HuR expression and function in breast cancer cell lines, in vivo animal models, and clinical studies is critically presented and summarized. HuR modulates many genes implicated in biological processes crucial for breast cancer formation, growth, and metastasis, whereas the link between HuR and these processes has been demonstrated directly in vitro and in vivo. Additionally, clinical studies reveal that HuR is associated with more aggressive forms of breast cancer and is a putative prognosticator for patients' survival. All the above indicate HuR as a promising drug target for cancer therapy; nevertheless, additional studies are required to fully understand its potential and determine against which types of breast cancer and at which stage of the disease a therapeutic agent targeting HuR would be more effective.Peer reviewedFinal Accepted Versio

Plasma TGF-beta 1-related survival of postmenopausal metastatic breast cancer patients

A pilot study was conducted to assess whether plasma levels of transforming growth factor-beta 1 (TGF-beta 1) might facilitate biological subgrouping of postmenopausal metastatic breast cancer patients, and, accordingly, its applicability in clinical oncology. This study included 29 postmenopausal metastatic breast cancer patients. Plasma TGF-beta 1 levels were detected by enzyme-linked immunosorbent assay (ELISA). Estrogen and progesterone receptors were assayed by radioligand binding, in accordance with the recommendation of the EORTC. Concentrations of 17-beta estradiol were determined by using ELISA-microwell method (DIALAB). Overall survival was followed for 24 months for each individual patient. Stratification of the patients by ER/PR status showed that 14 patients with estrogen receptor-negative, progesterone receptor-negative carcinomas displayed a statistically significant increase in plasma TGF-beta 1 levels when compared to plasma TGF-beta 1 levels of 6 patients with ER-positive, PR-positive carcinomas (P=0.04). In this study, 7 out of 14 patients with negative receptors status had no plasma TGF-beta 1 values overlapping with patients having positive receptors status. The TGF-beta 1 cut-off value was defined as the highest plasma TGF-beta 1 level of ER-positive, PR-positive patients: 3.28 ng/ml. This plasma TGF-beta 1 cut-off value defined low-risk subgroup of 19 patients (! 3.28 ng/ml) and high-risk subgroup of 10 patients ( GT 3.28 ng/ml) (P=0.047). Plasma TGF-beta 1-related survival was independent of the classical prognostic factors of metastatic breast cancer. Accordingly, a clinical significance of elevated plasma TGF-beta 1 levels may be suggested

Detection of transforming growth factor-beta 1 in human plasma - A pilot study on breast cancer patients

There has been much controversy concerning the detection of plasma TGF-beta (1) levels in breast cancer patients. The present study provides preliminary evidence on underestimated plasma TGF-beta (1) levels due to ex vivo proteolysis and previous therapeutic treatment of breast cancer patients, as detected by a commercial ELISA immunoassay. Our results revealed that the addition of protease inhibitors: phenylmethylsulfonyl fluoride and aprotinin, to the plasma preparation of healthy volunteers, has increased TGF-beta (1) median Value from 3.1 ng/mL to 33.9 ng/mL. Relative to that, in protease-inhibited plasma of locally advanced/metastatic breast cancer patients, significantly elevated TGF-beta (1) was observed (median value: 65.5 ng/mL), which included untreated and previously treated patients with median values of: 74.2 ng/mL and 58.1 ng/mL, respectively. These findings indicate to the potential usefulness of this plasma marker in breast cancer prognosis, thus deserving future clinical attention

Elevated plasma levels of transforming growth factor-beta(1) (TGF-beta(1)) in patients with advanced breast cancer: association with disease progression

We examined the association between an elevated plasma TGF-beta(1) level and the disease progression of advanced breast cancer (BC) patients (n = 44). TGF-beta(1) levels were detected by an enzyme-linked immunosorbent assay (ELISA). Platelet carryover and in vitro platelet activation in our plasma samples was assessed and found to be insignificant. Plasma TGF-beta(1) values were significantly elevated (P LT 0.05) in stage IIIB/IV patients (median value: 2.40 ng/ml, range: 0.13-8.48 ng/ml, n=44) compared with healthy donors (median value: 1.30 ng/ml, range: 0.41-4.93 ng/ml, n=36). Although pronounced in metastatic patients, especially those who had been newly diagnosed, TGF- and beta;(1) elevation was independent of tumour mass, site of distant metastases, histopathological type, steroid receptor (SR) content and age of the BC patients. Follow-up of 6 patients indicated a relationship between the plasma TGF- and beta;(1) and the patients response. This suggests that TGF- and beta;(1), may be a promising prognostic marker for breast cancer patients with advanced disease. Confirmatory large-scale studies are needed, particularly given the overlap of values between our different subgroups analysed. (C) 2003 Elsevier Science Ltd. All rights reserved

Localization of recognition site between transforming growth factor-beta(1) (TGF-beta(1)) and TGF beta receptor type II: possible implications in breast cancer

Although overexpression of TGF-beta(1) protein has been demonstrated in advanced breast cancer(BC) patients, as well as in other solid tumours, the molecular mechanism of this process remains obscure. This paper proposes that a genetic/epigenetic alteration might occur in the TGF-beta(1) gene, within the region coding for the recognition site with TGF(beta) receptor type II, leading to a disruption of the ligand-receptor interaction and triggering the TGF-beta(1) cascade-related BC progression. To establish the operational framework for this hypothesis, in the present study, this recognition site was identified by the Informational Spectrum Method (ISM) to comprise two TGF-beta(1) peptides (positions 47-66 as and 83-112 aa) and one receptor peptide at positions 112-151 as of the extracellular domain of the receptor (TbetaRII(M)). The TbetaRII(M) locus was further evaluated by ISM-derived deletion analysis of the TbetaRII sequences. To provide experimental support for the proposed model, a pilot study of plasma TGF-beta(1) analysis was performed in advanced BC patients (n = 8). Two commercial ELISA assays, one with specific alphaTGF-beta(1) MAb (MAb) and other with TbetaRII(M) as the immobilized phase, revealed pronounced differences in the pattern of plasma TGF-beta(1) elevation. In MAb-profile, the TGF-beta(1) increase was detected in 7 of 8 patients, whereas analogous TbetaRII(M)-profile revealed the elevation in 3 of 8 patients, taking a 50% of maximal elevation as the cut-off value. These findings are consistent with the proposed aberration of TGF-beta(1) ligand within the TbetaRII recognition site. Summarizing, this model system is a good starting point for further genetic studies, particularly on genetic/epigenetic alterations of sequences involved in TGF-beta(1) and TbetaRII(M) interaction, with putative prognostic value for breast cancer. (C) 2004 Elsevier Ltd. All rights reserved