Interleukin (IL)-17A in triple-negative breast cancer: a potent prognostic factor associated with intratumoral neutrophil infiltration

BACKGROUND

Triple-negative breast cancer (TNBC) is characterized as highly immunogenic and lacks specific targeted therapies. Interleukin 17A (IL-17A) is a controversial cytokine and is known to have anti-tumor and pro-tumor roles depending on the tumor microenvironment. In addition, IL-17A has been recently implicated in the recruitments of neutrophil into tumor tissues. Although IL-17A is considered tumor-promoting in breast cancer, its significance in the possible regulation of neutrophil infiltration in TNBC is not clearly defined.

MATERIALS AND METHODS

We immunolocalized IL-17A, CD66b (neutrophil marker), and chemokine (C-X-C motif) ligand 1 (CXCL1, neutrophil chemoattractant) in 108 TNBC specimens and assessed their correlation among each other. The correlation between these markers and clinicopathological parameters was also assessed. We subsequently performed in vitro study to address the possible regulation of CXCL1 by IL-17A using TNBC cell lines, MDA-MB-231 and HCC-38.

RESULTS

It was revealed that IL-17A correlated significantly with CXCL1 and CD66b, also CD66b with CXCL1. Furthermore, IL-17A was significantly associated with shorter disease-free and overall survival, especially in a high density CD66b group of patients. In vitro results revealed that IL-17A upregulated CXCL1 mRNA expression in a dose and time dependent manner, and this induction was significantly suppressed by an Akt inhibitor.

CONCLUSION

IL-17A was considered to contribute to neutrophil infiltration by inducing CXCL1 in TNBC tissues and educating neutrophils to promote tumor progression. IL-17A might therefore serve as a potent prognostic factor in TNBC.

ODP559 The prognostic role of IL-17A-neutrophils crosstalk in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer that is characterized by extensive intratumoral heterogeneity. At this juncture, TNBCs are treated with conventional chemotherapy and have few targeted therapies. Due to the presence of increased tumor-infiltrating lymphocytes and immune-checkpoint molecules, TNBCs are considered highly immunogenic. This provides an opportunity to explore various immunotherapeutic options. The immune cells such as Th17 cells or neutrophils (tumor-associated neutrophils; TANs) can secrete a pro-inflammatory cytokine called IL-17A, which is known to be associated with poor outcomes in several cancers. TANs are related to tumor progression and are influenced by certain chemokines. Meanwhile, IL-17A can also regulate chemokine (C-X-C motif) ligand 1 (CXCL1), which is a strong chemoattractant for TANs and can lead to the growth of tumors in breast cancer. However, the significance of IL-17A and its interaction with TANs and CXCL1 has yet not been clearly understood in TNBC. For this purpose, formalin-fixed paraffin-embedded biopsy tissue specimens of 109 Japanese TNBC patients were included in this study. Immunohistochemistry was performed to assess the status of IL-17A, CXCL1, and CD66b (a neutrophil marker) and to understand their correlation among each other, with clinical parameters, and with the outcomes of patients. Also, in vitro studies were performed to evaluate the effect of recombinant IL-17A on TNBC cell lines proliferation, migration, and CXCL1 expression. Clinical results revealed that IL-17A was significantly correlated with CXCL1 and CD66b, which suggested potential crosstalk between them. On the other hand, CXCL1 significantly and CD66b tended to be correlated with tumor size. Also, CD66b was significantly correlated with the Ki-67 labeling index, showing that TANs may have a role in tumor cell proliferation. Kaplan-Meier survival curves showed that high IL-17A was significantly associated with poor disease-free and overall survival, indicating the poor outcome of the TNBC patients. To our great interest, in vitro results revealed that no difference was observed for proliferation or migration of TNBC cell lines (was only observed in the MDA-MB-231 cell line) after treatment with recombinant IL-17A. However, CXCL1 was highly up-regulated in a dose and time-dependent manner after exposure to IL-17A, indicating that IL-17A might be involved in the recruitment of neutrophils through up-regulation of CXCL1. Therefore, we concluded that IL-17A was a poor prognostic factor for TNBC patients, enhancing the chemokine-neutrophil recruitment to the tumor site, leading to tumor progression and aggression. In the future, we intend to explore different pathways for understanding the mechanism of CXCL1 up-regulation by IL-17A.

Presentation: No date and time listed

Significance of glucocorticoid signaling in triple-negative breast cancer patients: a newly revealed interaction with androgen signaling

PURPOSE

Chemotherapy is the only current effective systemic treatment for triple-negative breast cancer (TNBC) patients. Therefore, the identification of active biological pathways that could become therapeutic targets is crucial. In this study, considering the well-reported biological roles of glucocorticoid and androgen receptors (GR, AR) in TNBC, we attempted to explore the effects of glucocorticoids (GCs) on cell kinetics as well as the potential interaction between GR and AR in TNBC.

METHODS

We first explored the association between the status of GR, AR, and/or GCs-metabolizing enzymes such as 11β-hydroxysteroid dehydrogenase (11βHSD) 1 and 2 and the clinicopathological variables of the TNBC patients. Thereafter, we also studied the effects of dexamethasone (DEX) with/without dihydrotestosterone (DHT) on TNBC cell lines by assessing the cell proliferation, migration and GC response genes at the transcriptional level.

RESULTS

GR positivity in carcinoma cells was significantly associated with adverse clinical outcome of the patients and AR positivity was significantly associated with lower histological grade and Ki-67 labeling index of the cases examined. In particular, AR positivity was significantly associated with decreased risks of developing recurrence in GR-positive TNBC patients. The subsequent in vitro studies revealed that DEX-promoted cell migration was inhibited by the co-treatment with DHT in GR/AR double-positive HCC38 cells. In addition, DHT inhibited the DEX-increased serum and glucocorticoid-regulated kinase-1 (SGK1) mRNA expression.

CONCLUSION

This is the first study to reveal that the interaction of GR and AR did influence the clinical outcome of TNBC patients and GCs induced cell migration in TNBC cells.

Androgen Receptor Is a Non-canonical Inhibitor of Wild-Type and Mutant Estrogen Receptors in Hormone Receptor-Positive Breast Cancers

Sustained treatment of estrogen receptor (ER)-positive breast cancer with ER-targeting drugs results in ER mutations and refractory unresponsive cancers. Androgen receptor (AR), which is expressed in 80%–95% of ER-positive breast cancers, could serve as an alternate therapeutic target. Although AR agonists were used in the past to treat breast cancer, their use is currently infrequent due to virilizing side effects. Discovery of tissue-selective AR modulators (SARMs) has renewed interest in using AR agonists to treat breast cancer. Using translational models, we show that AR agonist and SARM, but not antagonist, inhibit the proliferation and growth of ER-positive breast cancer cells, patient-derived tissues, and patient-derived xenografts (PDX). Ligand-activated AR inhibits wild-type and mutant ER activity by reprogramming the ER and FOXA1 cistrome and rendering tumor growth inhibition. These findings suggest that ligand-activated AR may function as a non-canonical inhibitor of ER and that AR agonists may offer a safe and effective treatment for ER-positive breast cancer.

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Androgen receptor (AR) agonists inhibit estrogen receptor (ER)-positive breast cancer

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Activating AR reprograms ER and FOXA1 cistrome, resulting in ER inhibition

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AR agonist alters the phosphoproteome signature consistent with growth inhibition

Impact of Topoisomerase IIα, PTEN, ABCC1/MRP1, and KI67 on triple-negative breast cancer patients treated with neoadjuvant chemotherapy

PURPOSE

Triple-negative breast cancer (TNBC) patients with residual disease following neoadjuvant chemotherapy (NAC) harbor higher risk of relapse, and eventual demise compared to those who achieve pathologic complete response. Therefore, in this study, we assessed a panel of molecules involved in key pathways of drug resistance and tumor progression before and after NAC in TNBC patients, in order to clarify the underlying mechanisms.

METHODS

We studied 148 TNBC Japanese patients treated with anthracycline/taxane-based NAC. KI67, Topoisomerase IIα (TopoIIα), PTEN, p53, Bcl2, vimentin, ABCG2/BCRP1, ABCB1/MDR1, and ABCC1/MRP1 were immunolocalized in surgical pathology materials before and after NAC.

RESULTS

The status of vimentin and increasing labeling index (LI) of TopoIIα and KI67 in biopsy specimens were significantly associated with those who responded to NAC treatment. The abundance of p53 (p = 0.003), ABCC1/MRP1 (p = 0.033), ABCB1/MDR1 (p = 0.022), and a loss of PTEN (p < 0.0001) in surgery specimens following treatment were associated with pathologic parameters. TopoIIα, PTEN, and ABCC1/MRP1 status predicted pathologic response. In addition, the status of PTEN, ABCC1/MRP1, ABCB1/MDR1, Bcl2, and vimentin in surgical specimens was also significantly associated with adverse clinicopathological factors in surgery specimens, suggesting that these alterations could be responsible for tumor relapse in TNBC patients.

CONCLUSION

KI67, TopoIIα, PTEN, and ABCC1/MRP1 status could predict treatment response and/or eventual clinical outcomes. These results could also provide an insight into the mechanisms of drug resistance and relapse of TNBC patients receiving NAC.

In breast cancer subtypes steroid sulfatase (STS) is associated with less aggressive tumour characteristics

BACKGROUND

The majority of breast cancer cases are steroid dependent neoplasms, with hormonal manipulation of either CYP19/aromatase or oestrogen receptor alpha axis being the most common therapy. Alternate pathways of steroid actions are documented, but their interconnections and correlations to BC subtypes and clinical outcome could be further explored.

METHODS

We evaluated selected steroid receptors (Androgen Receptor, Oestrogen Receptor alpha and Beta, Glucocorticoid Receptor) and oestrogen pathways (steroid sulfatase (STS), 17β-hydroxysteroid dehydrogenase 2 (17βHSD2) and aromatase) in a cohort of 139 BC cases from Norway. Using logistic and cox regression analysis, we examined interactions between these and clinical outcomes such as distant metastasis, local relapse and survival.

RESULTS

Our principal finding is an impact of STS expression on the risk for distant metastasis (p<0.001) and local relapses (p <0.001), HER2 subtype (p<0.015), and survival (p<0.001). The suggestion of a beneficial effect of alternative oestrogen synthesis pathways was strengthened by inverted, but non-significant findings for 17βHSD2.

CONCLUSIONS

Increased intratumoural metabolism of oestrogens through STS is associated with significantly lower incidence of relapse and/or distant metastasis and correspondingly improved prognosis. The enrichment of STS in the HER2 overexpressing subtype is intriguing, especially given the possible role of HER-2 over-expression in endocrine resistance.

Correction to: IRIS study: a phase II study of the steroid sulfatase inhibitor Irosustat when added to an aromatase inhibitor in ER-positive breast cancer patients

In the original publication of the article, a part of acknowledgement section was missed out. The omitted acknowledgement is given below: 'The study was coordinated by the Imperial Clinical Trials Unit-Cancer, Imperial College London and Sponsored by Imperial College London. The Imperial Clinical Trials Unit receives funding from the National Institute for Health (NIHR) Biomedical Research Centre based at Imperial College Healthcare NHS Trust and Imperial College London. The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR or the Department of Health. This study was supported by Imperial Experimental Cancer Medicine Centre and Cancer Research UK Imperial Centre'.

IRIS study: a phase II study of the steroid sulfatase inhibitor Irosustat when added to an aromatase inhibitor in ER-positive breast cancer patients

PURPOSE

Irosustat is a first-generation, orally active, irreversible steroid sulfatase inhibitor. We performed a multicentre, open label phase II trial of the addition of Irosustat to a first-line aromatase inhibitor (AI) in patients with advanced BC to evaluate the safety of the combination and to test the hypothesis that the addition of Irosustat to AI may further suppress estradiol levels and result in clinical benefit.

EXPERIMENTAL DESIGN

Postmenopausal women with ER-positive locally advanced or metastatic breast cancer who had derived clinical benefit from a first-line AI and who subsequently progressed were enrolled. The first-line AI was continued and Irosustat (40 mg orally daily) added. The primary endpoint was clinical benefit rate (CBR). Secondary endpoints included safety, tolerability, and pharmacodynamic end points.

RESULTS

Twenty-seven women were recruited, four discontinued treatment without response assessment. Based on local reporting, the CBR was 18.5% (95% CI 6.3-38.1%) on an intent to treat basis, increasing to 21.7% (95% CI 7.4-43.7%) by per-protocol analysis. In those patients that achieved clinical benefit (n = 5), the median (interquartile range) duration was 9.4 months (8.1-11.3) months. The median progression-free survival time was 2.7 months (95% CI 2.5-4.6) in both the ITT and per-protocol analyses. The most frequently reported grade 3/4 toxicities were dry skin (28%), nausea (13%), fatigue (13%), diarrhoea (8%), headache (7%), anorexia (7%) and lethargy (7%).

CONCLUSIONS

The addition of Irosustat to aromatase inhibitor therapy resulted in clinical benefit with an acceptable safety profile. The study met its pre-defined success criterion by both local and central radiological assessments.

Aromatase expression in atypical ductal hyperplasia in women

PURPOSE

To determine the levels of aromatase in atypical ductal hyperplasia (ADH) lesions, tissue surrounding the ADH, and in dense and non-dense normal breast tissue. We postulated that excess aromatase in breast tissue might, through production of increased estrogen, drive the carcinogenic process. Estrogens and their metabolites are thought to contribute to the development of breast cancer through estrogen receptor-mediated mechanisms and genotoxic effects of estrogen metabolites. ADH is a benign lesion of the breast which is associated with substantially increased risk for subsequent development of breast cancer. After 25 years, approximately 30% of women with ADH develop breast cancer. In women with three or more separate ADH lesions at the same time, 47% will develop breast cancer over that time period. Another important risk factor for breast cancer is the presence of mammographically dense breast tissue.

METHODS

We utilized quantitative immunochemical analysis of aromatase in biopsy tissue to test this possibility. Previously published results comparing dense with non-dense breast tissue in normal women (Vachon et al. Breast Cancer Res Treat 125:243-252, 2011) were used for comparisons with ADH. A well-characterized histochemical H-score was employed for quantitative assessment of aromatase in the various tissue studied.

RESULTS

The H-score of aromatase staining was statistically significantly higher (p = 0.003) in the ADH epithelium than surrounding epithelial tissue. In order of H-score from highest to lowest were ADH, issue surrounding ADH, dense normal and non-dense normal breast tissues. The levels of aromatase in a subset of women with ADH who went on to develop breast cancer were not higher than in women who did not.

CONCLUSIONS

We suggest from these studies that overexpression of aromatase in breast tissue and its resultant increase in estradiol levels may contribute to the later development of breast cancer in women with ADH.

Abstract P3-05-08: Steroid receptors and steroidogenic enzymes in human breast cancer: Associations with breast cancer subtypes and clinical outcome

Introduction: The majority of breast cancer (BC) cases are believed to be highly steroid dependent. Therefore exploitation of currently untapped steroid pathways could potentially contribute to our search for novel targeted breast cancer therapies. Given the growing understanding of the importance of both intratumoral steroid metabolism and impact of alternate steroid receptors in BC biology, we evaluated selected steroidogenic pathways in a cohort of 140 BC cases from Akershus University Hospital, Norway. In this study we immunolocalized both the androgen receptor (AR) and glucocorticoid receptor (GR) in addition to steroid sulfatase (STS) and 17β hydroxysteroid dehydrogenase 2 (17βHSD2). We also evaluated immunoreactivity of Ki-67 and CYP19/aromatase. We correlated these factors with the occurrence of distant metastasis or local relapse, and survival adjusted by age at surgery. We also examined whether any of these pathways were enriched in the classical breast cancer subtypes (Luminal A, Luminal B, HER-2 positive, triple-negative BC). Logistic and Cox regression analysis was employed to examine interactions between the above factors.

Results: In an analysis looking at possible interactions between recurrence and the factors above, the status of intratumoral STS was significantly inversely associated with distant metastasis (OR=0.17, p&lt;0.001) and local relapses (OR=0.17, p&lt;0.001), while that of 17βHSD2 trended towards correlation with the presence of metastasis (OR=3.47, p=0.055) and relapse (OR=3.14, p=0.07). Interestingly, ER and PR were not correlated with metastasis or relapse, but HER2 status positively correlated with distant metastasis during follow-up (OR=2.15, p=0.02) and trended to be associated with local relapses as well (OR=1.99, p=0.054). When evaluated according to the established breast cancer subtypes the only significant changes detected between subgroups were for AR and STS. AR was positive in a lesser proportion of the cases in the TNBC subgrouping (p=0.01), while STS was depleted in the luminal B and enriched in the HER2 subtypes (p=0.027). In an analysis of survival, STS was the only factor examined that was significantly associated with survival outcomes of the patients. Positive intratumoral STS status was significantly associated with improved survival (HR=0.27, p&lt;0.001). The inverse of this was also noticed for 17βHSD2 but the correlation did not reach statistical significance (HR=2.1, p=0.16).

Discussion and Conclusions: The results of our present study suggest that the intratumoral metabolism of estrogens through STS is associated with significantly lower incidence of relapse and/or distant metastasis and correspondingly a better prognosis. The inverse is also true when evaluating the trends noted with the expression of 17βHSD2 adding consistency to our finding above. The enrichment of STS in the HER2 overexpressing subtype of breast cancer is intriguing, especially given the possible role of HER-2 positivity in endocrine resistance. All in all, our results suggest that extended endocrine information about the intratumoral steroid metabolism of a given tumour may have so far unused prognostic potential and impact on clinical decision making.

Citation Format: McNamara KM, Guestini F, Sauer T, Lindstrøm JC, Sasano H, Geisler J. Steroid receptors and steroidogenic enzymes in human breast cancer: Associations with breast cancer subtypes and clinical outcome [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-05-08.

How far have we come in terms of estrogens in breast cancer? [Review]

Major advances in breast cancer treatment have almost always been linked to the actions of estrogen. Therefore, this review focused on estrogen actions in the breast, particularly the developments of the past 20 years, the present understanding of disease biology and possible future developments. Within these areas have focused on what is known about the underlying molecular biology and in particular integration of the bioinformatics revolution of the last 15 years with other facets of research. In addition, there will be an emphasis on the understanding brought about by a greater appreciation for the intracrinology of the breast.

Triple negative breast cancer chemosensitivity and chemoresistance: current advances in biomarkers indentification

INTRODUCTION

Triple negative breast cancer (TNBC) is a heterogeneous clinicopathological entity constituting approximately 15 - 20% of all breast cancer (BC) patients. It shows high recurrence rate and poor prognosis. At this juncture, because of the lack of specific targeted therapies available and the development in patients of resistance to some therapeutic agents, clinical and translational settings have gained importance over the past decades.

AREAS COVERED

The development of novel, safe and effective alternatives for the treatment of TNBC are in high demand. Therefore, this review aims to summarize the state of the art of TNBC, its current therapies and potential therapeutic targets. In particular, focus is put on recent advances regarding the identification of emerging biomarkers as prognostic and/or predictive markers, including surrogate markers for molecular tumor subtyping and identifying potential responders to new therapies.

EXPERT OPINION

Effective development of informative markers could constitute an important armamentarium tool for identifying appropriate therapies to challenge the aggressiveness of TNBC.