AZD8931, an equipotent, reversible inhibitor of signaling by epidermal growth factor receptor (EGFR), HER2, and HER3: preclinical activity in HER2 non-amplified inflammatory breast cancer models

HER3-targeted therapy: the mechanism of drug resistance and the development of anticancer drugs

Human epidermal growth factor receptor 3 (HER3), which is part of the HER family, is aberrantly expressed in various human cancers. Since HER3 only has weak tyrosine kinase activity, when HER3 ligand neuregulin 1 (NRG1) or neuregulin 2 (NRG2) appears, activated HER3 contributes to cancer development and drug resistance by forming heterodimers with other receptors, mainly including epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2). Inhibition of HER3 and its downstream signaling, including PI3K/AKT, MEK/MAPK, JAK/STAT, and Src kinase, is believed to be necessary to conquer drug resistance and improve treatment efficiency. Until now, despite multiple anti-HER3 antibodies undergoing preclinical and clinical studies, none of the HER3-targeted therapies are licensed for utilization in clinical cancer treatment because of their safety and efficacy. Therefore, the development of HER3-targeted drugs possessing safety, tolerability, and sensitivity is crucial for clinical cancer treatment. This review summarizes the progress of the mechanism of HER3 in drug resistance, the HER3-targeted therapies that are conducted in preclinical and clinical trials, and some emerging molecules that could be used as future designed drugs for HER3, aiming to provide insights for future research and development of anticancer drugs targeting HER3.

Utilization of Supervised Machine Learning to Understand Kinase Inhibitor Toxophore Profiles

There have been more than 70 FDA-approved drugs to target the ATP binding site of kinases, mainly in the field of oncology. These compounds are usually developed to target specific kinases, but in practice, most of these drugs are multi-kinase inhibitors that leverage the conserved nature of the ATP pocket across multiple kinases to increase their clinical efficacy. To utilize kinase inhibitors in targeted therapy and outside of oncology, a narrower kinome profile and an understanding of the toxicity profile is imperative. This is essential when considering treating chronic diseases with kinase targets, including neurodegeneration and inflammation. This will require the exploration of inhibitor chemical space and an in-depth understanding of off-target interactions. We have developed an early pipeline toxicity screening platform that uses supervised machine learning (ML) to classify test compounds’ cell stress phenotypes relative to a training set of on-market and withdrawn drugs. Here, we apply it to better understand the toxophores of some literature kinase inhibitor scaffolds, looking specifically at a series of 4-anilinoquinoline and 4-anilinoquinazoline model libraries.

Identification of Kinase Targets for Enhancing the Antitumor Activity of Eribulin in Triple-Negative Breast Cell Lines

Background: Triple-negative breast cancer (TNBC) is the most aggressive molecular subtype of breast cancer, and current treatments are only partially effective in disease control. More effective combination approaches are needed to improve the survival of TNBC patients. Eribulin mesylate, a non-taxane microtubule dynamics inhibitor, is approved by the U.S. Food and Drug Administration to treat metastatic breast cancer after at least two previous chemotherapeutic regimens. However, eribulin as a single agent has limited therapeutic efficacy against TNBC. Methods: High-throughput kinome library RNAi screening, Ingenuity Pathway Analysis, and STRING analysis were performed to identify target kinases for combination with eribulin. The identified combinations were validated using in vivo and ex vivo proliferation assays. Results: We identified 135 potential kinase targets whose inhibition enhanced the antiproliferation effect of eribulin in TNBC cells, with the PI3K/Akt/mTOR and the MAPK/JNK pathways emerging as the top candidates. Indeed, copanlisib (pan-class I PI3K inhibitor), everolimus (mTOR inhibitor), trametinib (MEK inhibitor), and JNK-IN-8 (pan-JNK inhibitor) produced strong synergistic antiproliferative effects when combined with eribulin, and the PI3K and mTOR inhibitors had the most potent effects in vitro. Conclusions: Our data suggest a new strategy of combining eribulin with PI3K or mTOR inhibitors to treat TNBC.

Genomic and microenvironmental heterogeneity shaping epithelial-to-mesenchymal trajectories in cancer

The epithelial to mesenchymal transition (EMT) is a key cellular process underlying cancer progression, with multiple intermediate states whose molecular hallmarks remain poorly characterised. To fill this gap, we present a method to robustly evaluate EMT transformation in individual tumours based on transcriptomic signals. We apply this approach to explore EMT trajectories in 7180 tumours of epithelial origin and identify three macro-states with prognostic and therapeutic value, attributable to epithelial, hybrid E/M and mesenchymal phenotypes. We show that the hybrid state is relatively stable and linked with increased aneuploidy. We further employ spatial transcriptomics and single cell datasets to explore the spatial heterogeneity of EMT transformation and distinct interaction patterns with cytotoxic, NK cells and fibroblasts in the tumour microenvironment. Additionally, we provide a catalogue of genomic events underlying distinct evolutionary constraints on EMT transformation. This study sheds light on the aetiology of distinct stages along the EMT trajectory, and highlights broader genomic and environmental hallmarks shaping the mesenchymal transformation of primary tumours.

Establishment of a new canine inflammatory mammary carcinoma cell line and analysis of its cystine-glutamate transporter subunit expression

Introduction

Inflammatory mammary carcinoma (IMC) is a rare disease with a poor prognosis and one affecting dogs. Inflammatory breast carcinoma (IBC) is a subtype of malignant breast cancer in humans with a high degree of malignancy and a similarly poor prognosis. Since the clinical symptoms and prognoses of both are similar, canine IMC has been considered as a model of human IBC. In this study, we newly established a stable IMC-derived cell line from a patient at the Yamaguchi University Animal Medical Center in Japan.

Material and Methods

The patient was a female toy poodle presenting with an inflamed mammary gland, which was diagnosed as IMC. The cell line was established from a tissue biopsy. Surface antigen marker (CD24 and CD44) expression was determined. Cystine/glutamate antiporter (xCT) expression was determined by Western blotting, flow cytometry and fluorescence immunostaining, and sulfasalazine was administered to ascertain if it suppressed xCT expression. Stem cell marker (Nanog, Sox2, Myc and Klf4) expression and aldehyde dehydrogenase (ALDH) activity were also investigated.

Results

The cultured cells showed xCT, and its suppression showed downregulation of stem cell markers and ALDH activity. Stable cell proliferation was verified.

Conclusion

A new canine IMC-derived cell line was established. In the future, we aim to study the effect of xCT on the maintenance of cancer stem cell properties in canine tumours, and propose a new therapeutic method for the treatment of canine IMC by targeting xCT.

Rosmarinic Acid Analogue-11 Induces Apoptosis of Human Gastric Cancer SGC-7901 Cells via the Epidermal Growth Factor Receptor (EGFR)/Akt/Nuclear Factor kappa B (NF-κB) Pathway

BACKGROUND According to the latest statistics from the American Cancer Society, there will be 1.73 million cancer cases and more than 600 000 cancer deaths in the United States in 2018, among which there will be 26 240 new cases of gastric cancer and around 10 800 deaths arising from gastric cancer. The objective of this study was to use RAA-11 to intervene in SGC-7901 cells to understand its effects on cell proliferation and apoptosis, and to explore the apoptosis mechanism. MATERIAL AND METHODS MTT assay was used to detect the survival of human gastric mucosal epithelial GES-1 cells and human gastric cancer SGC-7901 cells. Colony formation assay was used to observe the colony forming ability in SGC-7901 cells. The apoptotic rate of SGC-7901 cells was evaluated by Hoechst33258 staining and flow cytometry. qRT-PCR was used to analyze the epidermal growth factor receptor (EGFR) mRNA expression level in SGC-7901 cells. Western blot was used to examine the expression levels of caspase-3, Bcl-2, BAX, EGFR, Akt, p-Akt, and NF-κB in SGC-7901 cells. RESULTS RAA-11 is capable of inhibiting the proliferation and inducing the apoptosis of SGC-7901 cells in a time- and dose-dependent manner. Western blot showed that the expression levels of caspase-3 and BAX were upregulated, while the expression levels of Bcl-2, EGFR, Akt, p-Akt, and NF-κB in the SGC-7901 cells were downregulated. CONCLUSIONS Apoptosis can be induced in SGC-7901 cells by RAA-11, potentially via the EGFR/Akt/NF-κB pathway, indicating that RAA-11 might be a potent agent for cancer treatment.

HER2-targeted therapy: an emerging strategy in advanced colorectal cancer

INTRODUCTION

Colorectal cancer (CRC) is one of the most common malignant tumors; it is a focus of research globally, but the identification of clinically actionable oncogenic drivers remains elusive. Human epidermal growth factor receptor 2 (HER2) activation is present in approximately 5% of CRC and has acquired resistance to epidermal growth factor receptor (EGFR)-targeted therapy. Early clinical trials suggest an emerging role for personalized HER2-targeted therapy in a subset of metastatic CRC.

AREAS COVERED

This manuscript reviews the relevance of HER2 activation in CRC and its potential role as a target for therapy. A literature search was conducted in June 2018 of MEDLINE and EMBASE databases for published preclinical and clinical studies; abstracts of international cancer meetings (AACR, ASCO, and ESMO) were also reviewed.

EXPERT OPINION

HER2 is activated in a small but relevant proportion of CRC patients (particularly left-side, RAS wild-type, anti-EGFR resistant tumors). Dual HER2 blockade with monoclonal antibodies (mAbs) (trastuzumab and pertuzumab) or the combination of mAbs with tyrosine kinase inhibitors (trastuzumab and lapatinib) induces durable tumor responses in about one-third of HER2-positive CRC refractory to standard systemic therapy. Although immature, these results are remarkable and anticipate an expanding role for HER2 as a therapeutic target in CRC.

Human epidermal growth factor receptor targeted inhibitors for the treatment of ovarian cancer

Ovarian cancer is the second most lethal gynecological cancer worldwide and while most patients respond to initial therapy, they often relapse with resistant disease. Human epidermal growth factor receptors (especially HER1/EGFR and HER2/ERBB2) are involved in disease progression; hence, strategies to inhibit their action could prove advantageous in ovarian cancer patients, especially in patients resistant to first line therapy. Monoclonal antibodies and tyrosine kinase inhibitors are two classes of drugs that act on these receptors. They have demonstrated valuable antitumor activity in multiple cancers and their possible use in ovarian cancer continues to be studied. In this review, we discuss the human epidermal growth factor receptor family; review emerging clinical studies on monoclonal antibodies and tyrosine kinase inhibitors targeting these receptors in ovarian cancer patients; and propose future research possibilities in this area.

Inflammatory breast cancer biology: the tumour microenvironment is key

Inflammatory breast cancer (IBC) is a rare and aggressive disease that accounts for ~2-4% of all breast cancers. However, despite its low incidence rate, IBC is responsible for 7-10% of breast cancer-related mortality in Western countries. Thus, the discovery of robust biological targets and the development of more effective therapeutics in IBC are crucial. Despite major international efforts to understand IBC biology, genomic studies have not led to the discovery of distinct biological mechanisms in IBC that can be translated into novel therapeutic strategies. In this Review, we discuss these molecular profiling efforts and highlight other important aspects of IBC biology. We present the intrinsic characteristics of IBC, including stemness, metastatic potential and hormone receptor positivity; the extrinsic features of the IBC tumour microenvironment (TME), including various constituent cell types; and lastly, the communication between these intrinsic and extrinsic components. We summarize the latest perspectives on the key biological features of IBC, with particular emphasis on the TME as an important contributor to the aggressive nature of IBC. On the basis of the current understanding of IBC, we hope to develop the next generation of translational studies, which will lead to much-needed survival improvements in patients with this deadly disease.

Developmental therapeutics for inflammatory breast cancer: Biology and translational directions

Inflammatory breast cancer (IBC) is a rare and aggressive form of breast cancer, which accounts for approximately 3% of cases of breast malignancies. Diagnosis relies largely on its clinical presentation, and despite a characteristic phenotype, underlying molecular mechanisms are poorly understood. Unique clinical presentation indicates that IBC is a distinct clinical and biological entity when compared to non-IBC. Biological understanding of non-IBC has been extrapolated into IBC and targeted therapies for HER2 positive (HER2+) and hormonal receptor positive non-IBC led to improved patient outcomes in the recent years. This manuscript reviews recent discoveries related to the underlying biology of IBC, clinical progress to date and suggests rational approaches for investigational therapies.

First-line therapy in HER2 positive metastatic breast cancer: is the mosaic fully completed or are we missing additional pieces?

The discovery of human epidermal growth factor receptor 2 (HER2) and its role in the biology of breast cancer and the subsequent development of HER2-targeted therapies, have dramatically improved clinical outcomes for women with early-stage and advanced HER2-positive breast cancer (BC).

HER-2 targeted therapies represent a major step forward in achieving the goal of delivering individualized targeted therapy for BC, and trastuzumab was the first anti-HER-2 strategy to be approved for treatment of HER-2 positive BC.

This review discusses the treatment of metastatic HER2-positive BC and describes efficacy and safety of novel anti-HER2 target therapies in first-line metastatic settings and the future challenges include refining such treatments, reducing toxicity and simultaneously developing innovative therapies. Furthermore, combinations of trastuzumab and drugs targeting the downstream pathway are described.

In the next future will be possible to use an ample armamentarium of combination therapies directed against HER2 and key signaling components integrated in the HER network. This approach will allow clinicians to tailor the management of the individual patient on the basis of tumor- specific biomarker profiles.

There is an urgent need for prospective biomarker-driven trials to identify patients for whom targeting is cost-effective.

Immunoreactivity of the fully humanized therapeutic antibody PankoMab-GEX™ is an independent prognostic marker for breast cancer patients

Background

Mucin-1 (MUC1, CD227), more widely known as CA15-3, is an abundantly expressed epithelial cell surface antigen and has evolved to be the most predictive serum tumour marker in breast cancer. PankoMab-GEX™, which is currently being evaluated for its therapeutic efficacy in a phase IIb clinical trial, is a glyco-optimized anti-MUC1 antibody specifically recognizing a tumour-associated MUC1 epitope (TA-MUC1). The current study aimed to analyse the immunoreactivity of PankoMabGEX™ and its correlation with established clinico-pathological variables including 10-year and overall survival in a large cohort of breast cancer patients.

Methods

Breast cancer tissue sections (n = 227) underwent a standardized immunohistochemical staining protocol for TA-MUC1 by using PankoMab-GEX™ as a primary antibody. The staining was evaluated by two independent observers and quantified by applying the IR-score.

Results

TA-MUC1 as detected by PankoMab-GEX™ was identified in 74.9% of breast cancer tissue sections. Patients were subdivided according to the subcellular localisation of TA-MUC1 and cases classified as mem-PankoMab-GEX™ (solely membranous) positive, cyt-PankoMab-GEX™ (solely cytoplasmic) positive, double positive or as completely negative were compared regarding their survival. Herein mem-PankoMab-GEX™-positive patients performed best, while double-negative ones presented with a significantly shortened survival. Positivity for mem-PankoMab-GEX™ as well as a double-negative immunophenotype turned out to be independent prognosticators for survival.

Conclusions

This is the first study to report on PankoMab-GEX™ in a large panel of breast cancer patients. The PankoMab-GEX™ epitope TA-MUC1 could be identified in the majority of cases and was found to be an independent prognosticator depending on its subcellular localisation. Since TA-MUC1 is known to be highly immunogenic cancers staining positive for PankoMab-GEX™ might be more compromised by host anti-tumour immune defence. Further, the observations reported here might be fundamental for selecting patients to undergo PankoMab-GEX™-containing chemotherapy protocols.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-015-0152-7) contains supplementary material, which is available to authorized users.

Quercetin inhibits proliferation and invasion acts by up-regulating miR-146a in human breast cancer cells

Breast cancer is the most common female malignancies in the world which seriously impacts the female health. In recent years, various studies have been reported to determine the relevance of miRNAs to human cancer. One of these miRNAs, miR-146a has been down-regulated in multiple human cancer types, but up-regulation showed inducing apoptosis. To determine the role of quercetin treated on breast cancer, we investigated the effect of quercetin on cell proliferation in human breast cancer cell lines MCF-7 and MDA-MB-231 with/without transfection of miR-146a mimic or anti-miR-146a. Furthermore, the expressions of bax and cleaved-caspase-3, mainly were increased in control and overexpression miR-146a groups, however, the expression of EGFR was inverse. All the results demonstrated that quercetin exhibited excellent effect on inhibiting cell proliferation in human breast cancer cells, which was performed by up-regulating miR-146a expression, then via inducing apoptosis through caspase-3 activation and mitochondrial-dependent pathways, and inhibiting invasion through down-regulating the expression of EGFR.

Small molecule tyrosine kinase inhibitors of ErbB2/HER2/Neu in the treatment of aggressive breast cancer

The human epidermal growth factor receptor 2 (HER2) is a member of the erbB class of tyrosine kinase receptors. These proteins are normally expressed at the surface of healthy cells and play critical roles in the signal transduction cascade in a myriad of biochemical pathways responsible for cell growth and differentiation. However, it is widely known that amplification and subsequent overexpression of the HER2 encoding oncogene results in unregulated cell proliferation in an aggressive form of breast cancer known as HER2-positive breast cancer. Existing therapies such as trastuzumab (Herceptin®) and lapatinib (Tyverb/Tykerb®), a monoclonal antibody inhibitor and a dual EGFR/HER2 kinase inhibitor, respectively, are currently used in the treatment of HER2-positive cancers, although issues with high recurrence and acquired resistance still remain. Small molecule tyrosine kinase inhibitors provide attractive therapeutic targets, as they are able to block cell signaling associated with many of the proposed mechanisms for HER2 resistance. In this regard we aim to present a review on the available HER2 tyrosine kinase inhibitors, as well as those currently in development. The use of tyrosine kinase inhibitors as sequential or combinatorial therapeutic strategies with other HER family inhibitors is also discussed.