EGFR/HER2 in breast cancer: a biological approach for molecular diagnosis and therapy

Dermatologic toxicities in epidermal growth factor receptor: a comprehensive pharmacovigilance study from 2013 to 2023

Epidermal growth factor receptor inhibitors (EGFRIs) induced cutaneous toxicity is a common adverse event (AE), although it is not as severe as major cancers, we still need to pay enough attention to them. Therefore, it is necessary to evaluate the diversity of EGFRI class drugs. The objective of this study was to conduct a scientific and systematic investigation into the correlation between EGFRI and cutaneous toxicities. The data accessed from the FDA adverse event reporting system database (FAERS) encompass a time frame spanning from January 2013 to March 2023. By utilizing reporting odds ratios (RORs), information components (ICs), proportional reporting ratios (PRRs), and chi-squared (χ2), the relationship between drugs and adverse reactions was evaluated through disproportionality analysis. Within the FAERS database, a total of 29,559 skin adverse events were recorded. A robust indication of the correlation between EGFRI and elderly patients (≥65 years) was identified. Among EGFRIs, erlotinib accounted for the largest proportion of skin adverse events (39.72%). Rash, dry skin, and pruritus ranked top among all preferred terms, and signals such as rash, skin lesions, and acneiform dermatitis were detected in every single drug. Clinicians should guide patients customize the treatment plan for each patient.

Understanding the promising role of antibody drug conjugates in breast and ovarian cancer

A nascent category of anticancer therapeutic drugs called antibody-drug conjugates (ADCs) relate selectivity of aimed therapy using chemotherapeutic medicines with high cytotoxic power. Progressive linker technology led to the advancement of more efficacious and safer treatments. It offers neoteric as well as encouraging therapeutic strategies for treating cancer. ADCs selectively administer a medication by targeting antigens which are abundantly articulated on the membrane surface of tumor cells. Tumor-specific antigens are differently expressed in breast and ovarian cancers and can be utilized to direct ADCs. Compared to conventional chemotherapeutic drugs, this approach enables optimal tumor targeting while minimizing systemic damage. A cleavable linker improves the ADCs because it allows the toxic payload to be distributed to nearby cells that do not express the target protein, operating on assorted tumors with dissimilar cell aggregation. Presently fifteen ADCs are being studied in breast and ovarian carcinoma preclinically, and assortment of few have already undergone promising early-phase clinical trial testing. Furthermore, Phase I and II studies are investigating a wide variety of ADCs, and preliminary findings are encouraging. An expanding sum of ADCs will probably become feasible therapeutic choices as solo agents or in conjunction with chemotherapeutic agents. This review accentuates the most recent preclinical findings, pharmacodynamics, and upcoming applications of ADCs in breast and ovarian carcinoma.

Dual Targeting of EZH2 Degradation and EGFR/HER2 Inhibition for Enhanced Efficacy against Burkitt's Lymphoma

EZH2, a histone methyltransferase, contributes significantly to cancer cell survival and proliferation. Although various EZH2 inhibitors have demonstrated promise in treating lymphoma, they have not fully managed to curb lymphoma cell proliferation despite effective reduction of the H3K27me3 mark. We used MS1943, an EZH2 selective degrader, which successfully diminishes EZH2 levels in lymphoma cells. Additionally, lapatinib, a dual inhibitor of the epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) tyrosine kinases, targets a receptor protein that regulates cell growth and division. The overexpression of this protein is often observed in lymphoma cells. Our study aims to combine these two therapeutic targets to stimulate apoptosis pathways and potentially suppress Burkitt's lymphoma cell survival and proliferation in a complementary and synergistic manner. We observed that a combination of MS1943 and lapatinib induced apoptosis in Daudi cells and caused cell cycle arrest at the S and G2/M phases in both Ramos and Daudi cells. This strategy, using a combination of MS1943 and lapatinib, presents a promising therapeutic approach for treating lymphoma and potentially Burkitt's lymphoma.

Expression-Based Diagnosis, Treatment Selection, and Drug Development for Breast Cancer

There is currently no gene expression assay that can assess if premalignant lesions will develop into invasive breast cancer. This study sought to identify biomarkers for selecting patients with a high potential for developing invasive carcinoma in the breast with normal histology, benign lesions, or premalignant lesions. A set of 26-gene mRNA expression profiles were used to identify invasive ductal carcinomas from histologically normal tissue and benign lesions and to select those with a higher potential for future cancer development (ADHC) in the breast associated with atypical ductal hyperplasia (ADH). The expression-defined model achieved an overall accuracy of 94.05% (AUC = 0.96) in classifying invasive ductal carcinomas from histologically normal tissue and benign lesions (n = 185). This gene signature classified cancer development in ADH tissues with an overall accuracy of 100% (n = 8). The mRNA expression patterns of these 26 genes were validated using RT-PCR analyses of independent tissue samples (n = 77) and blood samples (n = 48). The protein expression of PBX2 and RAD52 assessed with immunohistochemistry were prognostic of breast cancer survival outcomes. This signature provided significant prognostic stratification in The Cancer Genome Atlas breast cancer patients (n = 1100), as well as basal-like and luminal A subtypes, and was associated with distinct immune infiltration and activities. The mRNA and protein expression of the 26 genes was associated with sensitivity or resistance to 18 NCCN-recommended drugs for treating breast cancer. Eleven genes had significant proliferative potential in CRISPR-Cas9/RNAi screening. Based on this gene expression signature, the VEGFR inhibitor ZM-306416 was discovered as a new drug for treating breast cancer.

Development of Electrochemical Immunosensors for HER-1 and HER-2 Analysis in Serum for Breast Cancer Patients

In this work, two human epidermal growth factor receptors, HER-1 and HER-2, were selected as biomarkers to enable the detection of breast cancer. Therefore, two biosensors were developed using gold sensor chips coupled with amperometric detection of the enzyme label horse radish peroxidase (HRP). The biosensors/immunosensors relied on indirect sandwich enzyme-linked immunosorbent assays with monoclonal antibodies (Ab) against HER-1 and HER-2 attached to the sensors to capture the biomarkers. Detection polyclonal antibodies followed by secondary anti-rabbit (for HER-1) and anti-goat (for HER-2) IgG antibody-HRP were then applied for signal generation. In buffer, the developed sensors showed limits of detections (LOD) of 1.06 ng mL^-1 and 0.95 ng mL^-1 and limits of quantification (LOQ) of 2.1 ng mL^-1 and 1.5 ng mL^-1 for HER-1 and HER-2, respectively. In 100% (undiluted) serum, LODs of 1.2 ng mL^-1 and 1.47 ng mL^-1 and LOQs of 1.5 ng mL^-1 and 2.1 ng mL^-1 were obtained for HER-1 and HER-2, respectively. Such limits of detections are within the serum clinical range for the two biomarkers. Furthermore, gold nanoparticles (AuNP) labelled with secondary anti-rabbit and anti-goat IgG antibody-HRP were then used to enhance the assay signal and increase the sensitivity. In buffers, LODs of 30 pg mL^-1 were seen for both sensors and LOQs of 98 pg mL^-1 and 35 pg mL^-1 were recorded for HER-1 and HER-2, respectively. For HER-2 the AuNPs biosensor was also tested in 100% serum obtaining a LOD of 50 pg mL^-1 and a LOQ of 80 pg mL^-1. The HER-2 AuNP electrochemical immunosensor showed high specificity with very low cross-reactivity to HER-1. These findings demonstrate that the two developed sensors can enable early detection as well as monitoring of disease progression with a beneficial impact on patient survival and clinical outcomes.

Precision and Accuracy of Receptor Quantification on Synthetic and Biological Surfaces Using DNA-PAINT

Characterization of the number and distribution of biological molecules on 2D surfaces is of foremost importance in biology and biomedicine. Synthetic surfaces bearing recognition motifs are a cornerstone of biosensors, while receptors on the cell surface are critical/vital targets for the treatment of diseases. However, the techniques used to quantify their abundance are qualitative or semi-quantitative and usually lack sensitivity, accuracy, or precision. Detailed herein a simple and versatile workflow based on super-resolution microscopy (DNA-PAINT) was standardized to improve the quantification of the density and distribution of molecules on synthetic substrates and cell membranes. A detailed analysis of accuracy and precision of receptor quantification is presented, based on simulated and experimental data. We demonstrate enhanced accuracy and sensitivity by filtering out non-specific interactions and artifacts. While optimizing the workflow to provide faithful counting over a broad range of receptor densities. We validated the workflow by specifically quantifying the density of docking strands on a synthetic sensor surface and the densities of PD1 and EGF receptors (EGFR) on two cellular models.

Small Molecule Compounds of Natural Origin Target Cellular Receptors to Inhibit Cancer Development and Progression

Receptors are macromolecules that transmit information regulating cell proliferation, differentiation, migration and apoptosis, play key roles in oncogenic processes and correlate with the prognoses of cancer patients. Thus, targeting receptors to constrain cancer development and progression has gained widespread interest. Small molecule compounds of natural origin have been widely used as drugs or adjuvant chemotherapeutic agents in cancer therapies due to their activities of selectively killing cancer cells, alleviating drug resistance and mitigating side effects. Meanwhile, many natural compounds, including those targeting receptors, are still under laboratory investigation for their anti-cancer activities and mechanisms. In this review, we classify the receptors by their structures and functions, illustrate the natural compounds targeting these receptors and discuss the mechanisms of their anti-cancer activities. We aim to provide primary knowledge of mechanistic regulation and clinical applications of cancer therapies through targeting deregulated receptors.

Differences in Extracellular Vesicle Protein Cargo Are Dependent on Head and Neck Squamous Cell Carcinoma Cell of Origin and Human Papillomavirus Status

To identify potential extracellular vesicle (EV) biomarkers in head and neck squamous cell carcinoma (HNSCC), we evaluated EV protein cargo and whole cell lysates (WCL) from HPV-positive and -negative HNSCC cell lines, as well as normal oral keratinocytes and HPV16-transformed cells. EVs were isolated from serum-depleted, conditioned cell culture media by polyethylene glycol (PEG) precipitation/ultracentrifugation. EV and WCL preparations were analyzed by LC-MS/MS. Candidate proteins detected at significantly higher levels in EV compared with WCL, or compared with EV from normal oral keratinocytes, were identified and confirmed by Wes Simple Western protein analysis. Our findings suggest that these proteins may be potential HNSCC EV markers as proteins that may be (1) selectively included in EV cargo for export from the cell as a strategy for metastasis, tumor cell survival, or modification of tumor microenvironment, or (2) representative of originating cell composition, which may be developed for diagnostic or prognostic use in clinical liquid biopsy applications. This work demonstrates that our method can be used to reliably detect EV proteins from HNSCC, normal keratinocyte, and transformed cell lines. Furthermore, this work has identified HNSCC EV protein candidates for continued evaluation, specifically tenascin-C, HLA-A, E-cadherin, EGFR, EPHA2, and cytokeratin 19.

ARA-linker-TGFαL3: a novel chimera protein to target breast cancer cells

Targeted cancer therapies based on overexpressed receptors and the fractions containing immunotoxins and bacterial metabolites are one of the well-known methods to overcome the chemotherapy resistance of cancer cells. In this paper, we designed ARA-linker-TGFαL3, using Arazyme, a Serratia proteamaculans metabolite, and a third loop segment of TGFα to target EGFR-expressing breast cancer cells. After cloning in pET28a (+), the expression of recombinant protein was optimized in Escherichia coli strain BL21 (DE3). MDA-MB-468 (EGFR positive) and MDA-MB-453 (EGFR negative) breast cancer cell lines were employed. Also, the chemotherapeutic drug, Taxotere (Docetaxel), was employed to compare cytotoxicity effects. Cell ELISA assessed the binding affinity of recombinant proteins to the receptor, and the cytotoxicity was detected by MTT and lactate dehydrogenase release assays. The interfacing with cancer cell adhesion was evaluated. Furthermore, the induction of apoptosis was examined utilizing flow cytometric analysis, and caspase-3 activity assay. Moreover, RT-PCR was conducted to study the expression of apoptosis (bax, bcl2, and casp3), angiogenesis (vegfr2), and metastasis (mmp2 and mmp9) genes. ARA-linker-TGFαL3 revealed a higher binding affinity, cytotoxicity, and early apoptosis induction in MDA-MB-468 cells compared to the effects of Arazyme while both recombinant proteins showed similar effects on MDA-MB-453. In addition, the Taxotere caused the highest cytotoxicity on cancer cells through induction of late apoptosis. Meanwhile, the expression of angiogenesis and metastasis genes was decreased in both cell lines after treatment with either ARA-linker-TGFαL3 or Arazyme. Our in vitro results indicated the therapeutic effect of ARA-linker-TGFαL3 on breast cancer cells.

Trastuzumab deruxtecan in HER2-positive metastatic breast cancer and beyond

INTRODUCTION

Despite the substantial improvements made in human epidermal growth factor receptor 2 (HER2)-targeted therapies since the approval of trastuzumab more than 20 years ago, there is still considerable unmet need in patients with HER2-expressing breast cancer (BC) and other solid tumors. Trastuzumab deruxtecan (T-DXd) is a newer antibody-drug conjugate approved for the treatment of metastatic breast cancer (BC) and gastric cancer (GC) and is under active investigation in other solid tumors, including non-small cell lung cancer, colorectal cancer, and HER2-low tumors.

AREAS COVERED

The current treatment and investigational landscape of HER2-positive and HER2-low metastatic BC (mBC) and the preclinical and clinical trials investigating T-DXd. To identify relevant literature, a search was performed on English-language publications and congress abstracts.

EXPERT OPINION

T-DXd is likely to become the standard of care for second-line treatment of HER2-positive mBC, and it may play a role in the treatment of hormone receptor-positive and triple-negative mBC with HER2-low expression. Because it was recently approved in the United States and Japan to treat HER2-positive metastatic GC, it holds promise for the treatment of other HER2-positive solid tumors, including colorectal cancer, non-small cell lung cancer, and HER2-low BC.

Developing Symptom Lists for People with Cancer Treated with Targeted Therapies

BACKGROUND

Targeted therapies (TTs) have revolutionised cancer treatment with their enhanced specificity of action. Compared with conventional therapies, TTs are delivered over a longer period and often have unusual symptom profiles. Patient-reported outcome measures such as symptom side-effect lists need to be developed in a time-efficient manner to enable a rapid and full evaluation of new treatments and effective clinical management OBJECTIVE: The aim of this study was to develop a set of TT-related symptoms and identify the optimal method for developing symptom lists.

PATIENTS AND METHODS

Symptoms from TT treatment in the context of Chronic Myeloid Leukaemia (CML), HER2-positive breast cancer, or Gastrointestinal Stromal Tumours (GIST) were identified through literature reviews, interviews with healthcare professionals (HCPs) and patients, and patient focus groups. The symptom set was then pilot tested in patients across the three cancer diagnoses: The number of items derived from each source (literature, patients, or HCPs) were compared.

RESULTS

A total of 316 patients and 86 HCPs from 16 countries participated. An initial set of 209 symptoms was reduced to 61 covering 12 symptom categories. Patient interviews made the greatest contribution to the item set.

CONCLUSIONS

Symptom lists should be created based on input from patients. The item set described will be applicable to the assessment of new TTs, and in monitoring treatment.

A practical and adaptive approach to lung cancer screening: a review of international evidence and position on CT lung cancer screening in the Singaporean population by the College of Radiologists Singapore

Lung cancer is the leading cause of cancer-related death around the world, being the top cause of cancer-related deaths among men and the second most common cause of cancer-related deaths among women in Singapore. Currently, no screening programme for lung cancer exists in Singapore. Since there is mounting evidence indicating a different epidemiology of lung cancer in Asian countries, including Singapore, compared to the rest of the world, a unique and adaptive approach must be taken for a screening programme to be successful at reducing mortality while maintaining cost-effectiveness and a favourable risk-benefit ratio. This review article promotes the use of low-dose computed tomography of the chest and explores the radiological challenges and future directions.

Design, synthesis, chemical characterization, biological evaluation, and docking study of new 1,3,4-oxadiazole homonucleoside analogs

Herein, we report the synthetic strategies and characterization of some novel 1,3,4-oxadiazole homonucleoside analogs that are relevant to potential antitumor and cytotoxic activities. The structure of all compounds is confirmed using various spectroscopic methods such as ¹H-NMR, ¹³C-NMR, HRMS, and FTIR. These compounds were evaluated against three human cancer cell lines (MCF-7, SKBR3, and HL60 Cell Line). Preliminary investigations showed that the cytotoxic activity was markedly dependent on the nucleobase. Introduction of 5-Iodouracil 4g and theobromine 6b proved to be extremely beneficial even they were more potent than the reference drug (DOX). Also, the synthesized compounds were tested for their antiviral activities against the human varicella-zoster virus (VZV). The product 4h was (6-azauracil derivative) more potent to the reference (acyclovir) against the deficient TK - VZV strain by about 2-fold. Finally, molecular docking suggested that the anticancer activities of compounds 6b and 4g mediated by inhibiting dual proteins EGFR/HER2 with low micromolar inhibition constant Ki range. The 1,3,4-oxadiazole homonucleosides showed a strong affinity to binding sites of target proteins by forming H-bond, carbon-hydrogen bond, Pi-anion, Pi-sulfur, Pi-sigma, alkyl, and Pi-alkyl interactions.

Exploring Collagen Parameters in Pure Special Types of Invasive Breast Cancer

One of the promising tools to evaluate collagen in the extracellular matrix is the second-harmonic generation microscopy (SHG). This approach may shed light on the biological behavior of cancers and their taxonomy, but has not yet been applied to characterize collagen fibers in cases diagnosed as invasive breast carcinoma (BC) of histological special types (IBC-ST). Tissue sections from 99 patients with IBC-ST and 21 of invasive breast carcinoma of no special type (IBC-NST) were submitted to evaluation of collagen parameters by SHG. Tissue microarray was performed to evaluate immunohistochemical-based molecular subtype. In intratumoral areas, fSHG and bSHG (forward-SHG and backward-SHG) collagen parameters achieved their lowest values in mucinous, papillary and medullary carcinomas, whereas the highest values were found in classic invasive lobular and tubular carcinomas. Unsupervised hierarchical cluster analysis and minimal spanning tree using intratumoral collagen parameters allowed the identification of three main groups of breast cancer: group A (classic invasive lobular and tubular carcinomas); group B (IBC-NST, metaplastic, invasive apocrine and micropapillary carcinomas); and group C (medullary, mucinous and papillary carcinomas). Our findings provide further characterization of the tumor microenvironment of IBC-ST. This understanding may add information to build more consistent tumor categorization and to refine prognostication.

Disulfide bond disrupting agents activate the unfolded protein response in EGFR- and HER2-positive breast tumor cells

Many breast cancer deaths result from tumors acquiring resistance to available therapies. Thus, new therapeutic agents are needed for targeting drug-resistant breast cancers. Drug-refractory breast cancers include HER2+ tumors that have acquired resistance to HER2-targeted antibodies and kinase inhibitors, and “Triple-Negative” Breast Cancers (TNBCs) that lack the therapeutic targets Estrogen Receptor, Progesterone Receptor, and HER2. A significant fraction of TNBCs overexpress the HER2 family member Epidermal Growth Factor Receptor (EGFR). Thus agents that selectively kill EGFR+ and HER2+ tumors would provide new options for breast cancer therapy. We previously identified a class of compounds we termed Disulfide bond Disrupting Agents (DDAs) that selectively kill EGFR+ and HER2+ breast cancer cells in vitro and blocked the growth of HER2+ breast tumors in an animal model. DDA-dependent cytotoxicity was found to correlate with downregulation of HER1-3 and Akt dephosphorylation. Here we demonstrate that DDAs activate the Unfolded Protein Response (UPR) and that this plays a role in their ability to kill EGFR+ and HER2+ cancer cells. The use of breast cancer cell lines ectopically expressing EGFR or HER2 and pharmacological probes of UPR revealed all three DDA responses: HER1-3 downregulation, Akt dephosphorylation, and UPR activation, contribute to DDA-mediated cytotoxicity. Significantly, EGFR overexpression potentiates each of these responses. Combination studies with DDAs suggest that they may be complementary with EGFR/HER2-specific receptor tyrosine kinase inhibitors and mTORC1 inhibitors to overcome drug resistance.

FoxM1: Repurposing an oncogene as a biomarker

The past few decades have witnessed a tremendous progress in understanding the biology of cancer, which has led to more comprehensive approaches for global gene expression profiling and genome-wide analysis. This has helped to determine more sophisticated prognostic and predictive signature markers for the prompt diagnosis and precise screening of cancer patients. In the search for novel biomarkers, there has been increased interest in FoxM1, an extensively studied transcription factor that encompasses most of the hallmarks of malignancy. Considering the attractive potential of this multifarious oncogene, FoxM1 has emerged as an important molecule implicated in initiation, development and progression of cancer. Bolstered with the skill to maneuver the proliferation signals, FoxM1 bestows resistance to contemporary anti-cancer therapy as well. This review sheds light on the large body of literature that has accumulated in recent years that implies that FoxM1 neoplastic functions can be used as a novel predictive, prognostic and therapeutic marker for different cancers. This assessment also highlights the key features of FoxM1 that can be effectively harnessed to establish FoxM1 as a strong biomarker in diagnosis and treatment of cancer.

Selective uptake of epidermal growth factor-conjugated gold nanoparticle (EGF-GNP) facilitates non-thermal plasma (NTP)-mediated cell death

Non-thermal atmospheric pressure plasma (NTP) has been shown to induce cell death in various mammalian cancer cells. Accumulated evidence also shows that NTP could be clinically used in cancer therapy. However, the current NTP-based applications lack target specificity. Here, a novel method in NTP-mediated cancer therapeutics was described with enhanced target specificity by treating EGF (epidermal growth factor)-conjugated GNP (gold nanoparticle). The treatment with EGF-conjugated GNP complex, followed by NTP irradiation showed selective apoptosis of cells having receptor-mediated endocytosis. NTP triggered γ-H2AX elevation which is a typical response elicited by DNA damage. These results suggest that EGF-conjugated GNP functions as an important adjuvant which gives target specificity in applications of conventional plasma therapy.

Protein A Functionalized Polyelectrolyte Microcapsules as a Universal Platform for Enhanced Targeting of Cell Surface Receptors

Targeted delivery systems recognizing specific receptors are a key element in personalized medicine. Such systems allow the delivery of therapeutics to desired sites of the body, increasing their local concentration and thus reducing the side effects. In this study, we fabricate chemically cross-linked (PAH/PAA)₂ microcapsules coated with specific cell-targeting antibodies in random (via direct covalent coupling to the surface) or optimized (via supporting layer of protein A) orientation. We use these antibody-functionalized capsules to target major histocompatibility complex (MHC) class I receptors in living cells and quantify the efficiency of targeting by flow cytometry. We show for the first time the selective binding of polyelectrolyte microcapsules to MHC class I receptors, and confirm that targeting is allotype-specific. Remarkably, protein A assisted immobilization of antibodies enhances targeting efficiency by 40-50% over capsules with randomly attached antibodies. Moreover, biofunctionalized capsules reveal low levels of cytotoxicity and nonspecific binding, excluding the need of additional modification with poly(ethylene glycol). Thus, protein A coated (PAH/PAA)₂ microcapsules represent a unique example of universal targeting tools providing high potential for selective binding to a broad range of cell surface receptors.

BRCA1 and BRCA2 mutations in males with familial breast and ovarian cancer syndrome. Results of a Spanish multicenter study

Male breast cancer (MBC) is a rare disease that represents <1% of all breast cancers (BCs). We analyze the results of a multicenter study performed in Spanish familial MBC including family history of hereditary breast and ovarian cancer syndrome (HBOCS) and clinicopathological features. We also study the relationship between BRCA1/BRCA2 mutational status in male relatives affected with cancer (MAC) and, family history and tumor types. The study included 312 men index cases with family history of HBOCS and 61 MAC BRCA1/2 mutation-carriers. Family history, histological grade (HG), clinicopathological and immunohistochemistry data were collected. BRCA1/2 mutation analyses were performed by direct sequencing or screening methods and the large rearrangements by multiplex ligation dependent probe amplification. We found 49 mutation-carriers (15.7%), 95.9% with BRCA2 mutations. BRCA2 mutation-carriers were associated with families with at least one MBC and one BC in female (type II; p = 0.05). Strong association were found between the presence of pathogenic mutations in MBCs and the advanced HG (p = 0.003). c.658_659delTG, c.2808_2811delACAA, c.6275_6276delTT and c.9026_9030delATCAT were the most prevalent mutations. In 61 MAC we found 20 mutations in BRCA1 and 41 in BRCA2. For MAC we show that mutational status was differentially associated with family history (p = 0.018) and tumor type, being BRCA2 mutations linked with BC and prostatic cancer (p = 0.018). MBC caused by BRCA1/2 mutations define two types of MBCs. The most frequent caused by BRCA2 mutation linked to type II families and the rarest one attributed to BRCA1 mutation. Tumor associated with MAC suggest that only BRCA2 mutations have to do with a specific type of cancer (BC and prostatic cancer); but the linkage to tumors is questionable for BRCA1 mutations .

Epigallocatechin Gallate Nanodelivery Systems for Cancer Therapy

Cancer is one of the leading causes of morbidity and mortality all over the world. Conventional treatments, such as chemotherapy, are generally expensive, highly toxic and lack efficiency. Cancer chemoprevention using phytochemicals is emerging as a promising approach for the treatment of early carcinogenic processes. (−)-Epigallocatechin-3-gallate (EGCG) is the major bioactive constituent in green tea with numerous health benefits including anti-cancer activity, which has been intensively studied. Besides its potential for chemoprevention, EGCG has also been shown to synergize with common anti-cancer agents, which makes it a suitable adjuvant in chemotherapy. However, limitations in terms of stability and bioavailability have hampered its application in clinical settings. Nanotechnology may have an important role in improving the pharmacokinetic and pharmacodynamics of EGCG. Indeed, several studies have already reported the use of nanoparticles as delivery vehicles of EGCG for cancer therapy. The aim of this article is to discuss the EGCG molecule and its associated health benefits, particularly its anti-cancer activity and provide an overview of the studies that have employed nanotechnology strategies to enhance EGCG’s properties and potentiate its anti-tumoral activity.

Visible to Near-Infrared Fluorescence Enhanced Cellular Imaging on Plasmonic Gold Chips

Rapid and sensitive detections of a variety of surface and intracellular proteins, nucleic acids, and other cellular biomarkers are important to elucidating biological signaling pathways and to devising disease diagnostics and therapeutics. Here, sensitive imaging and detection of cellular proteins on fluorescence-enhancing, nanostructured plasmonic gold (pGold) chips is presented. Imaging of fluorescently labeled cellular biomarkers on pGold is enhanced by 2-30-fold in the visible to near infrared (NIR) range of ≈500-900 nm. The high fluorescence enhancement of >700 nm significantly improves the dynamic range and signal/background ratios of NIR imaging, allowing high-performance multicolor imaging in the visible-NIR range using high quantum yield (QY) visible dyes and lower QY NIR fluorophores. Further, multiple cellular proteins of single cells of various cell types can be detected through microarraying of cells, useful for potentially hundreds and thousands different types of cells assayed on a single chip down to small cell numbers. This work suggests a simple, high throughput, high sensitivity, and multiplexed single-cell analysis method on fluorescence enhancing plasmonic substrates in the entire visible to NIR window.

Midline2 is overexpressed and a prognostic indicator in human breast cancer and promotes breast cancer cell proliferation in vitro and in vivo

Midline2 (MID2) is an ubiquitin-conjugating E2 enzyme linked to tumor progression and a novel interacting partner of breast cancer 1, early-onset (BRCA1). However, the role of MID2 in breast cancer remains unknown. This study investigated the expression, prognostic value, and role of MID2 in breast cancer. The expression of MID2 mRNA and protein was significantly upregulated in breast cancer tissue and established cell lines compared with that in normal breast epithelial cells and paired adjacent non-tumor tissue (P < 0.001). Immunohistochemical analysis demonstrated that MID2 was overexpressed in 272 of 284 (95.8%) paraffinembedded, archived breast cancer tissue. Moreover, MID2 expression increased with advanced clinical stage (P < 0.001). High MID2 expression was significantly associated with advanced clinical stages and T, N, and M staging (all P < 0.05). Univariate and multivariate analyses indicated that high MID2 expression was an independent prognostic factor for poor overall survival in the entire cohort (93.73 vs. 172.1 months; P < 0.001, logrank test) and in subgroups with stages Tis + I + II and III + IV. Furthermore, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide colony formation, and anchorage-independent growth ability assays were conducted. Results showed that siRNA silencing of MID2 expression significantly reduced MCF-7 and MDA-MB-231 cell proliferation in vitro and blocked the growth of MDA-MB-231 cell xenograft tumors in vivo (P < 0.05). This study indicated that MID2 may be a novel prognostic marker and interventional target in breast cancer.

Distinct effects of β1 integrin on cell proliferation and cellular signaling in MDA-MB-231 breast cancer cells

An aberrant expression of integrin β1 has been implicated in breast cancer progression. Here, we compared the cell behaviors of wild-type (WT), β1 gene deleted (KO), and β1 gene restored (Res) MDA-MB-231 cells. Surprisingly, the expression of β1 exhibited opposite effects on cell proliferation. These effects were dependent on cell densities, and they showed an up-regulation of cell proliferation when cells were cultured under sparse conditions, and a down-regulation of cell growth under dense conditions. By comparison with WT cells, the phosphorylation levels of ERK in KO cells were consistently suppressed under sparse culture conditions, but consistently up-regulated under dense culture conditions. The phosphorylation levels of EGFR were increased in the KO cells. By contrast, the phosphorylation levels of AKT were decreased in the KO cells. The abilities for both colony and tumor formation were significantly suppressed in the KO cells, suggesting that β1 plays an important role in cell survival signaling for tumorigenesis. These aberrant phenotypes in the KO cells were rescued in the Res cells. Taken together, these results clearly showed the distinct roles of β1 in cancer cells: the inhibition of cell growth and the promotion of cell survival, which may shed light on cancer therapies.

High EGFR protein expression and exon 9 PIK3CA mutations are independent prognostic factors in triple negative breast cancers

BACKGROUND

Triple negative breast cancers (TNBC) are a more aggressive subset of breast cancer. A better understanding of its biology could allow the rational development of targeted therapies.

METHODS

We extensively analyzed the EGFR/PI3K/PTEN axis in a large, homogeneous population of TNBC to help defining the putative role of anti-EGFR and -PI3K targeted therapies in this setting. EGFR gene amplification, EGFR protein expression, PIK3CA and PTEN gene alterations (two members of EGFR downstream pathways) and their clinicopathological and prognostic implications were analyzed in 204 TNBC samples from European patients.

RESULTS

EGFR amplification was detected in 18 of the 204 TNBC specimens (8.9 %) and was significantly associated with higher EGFR protein levels. Fourteen PIK3CA mutations were identified in exon 9 (6.7 %), and 17 in exon 20 (8.3 %). PIK3CA mutations, especially in exon 9, were significantly associated with grade I-II tumors. PTEN deletions were detected in 43 samples (21.50 %) and were significantly associated with grade III tumors (p < 0.001). Univariate analysis showed a significant association between relapse-free survival (RFS), T and N stage and exon 9 PIK3CA mutations. Overall survival was significantly associated with T stage, N stage and adjuvant chemotherapy, which was administered to 70.3 % of patients. In multivariate analyses, T stage, N stage, presence of exon 9 PIK3CA mutations and high EGFR protein level were independent poor prognostic factors for RFS, while adjuvant chemotherapy was associated with a better outcome.

CONCLUSIONS

High EGFR protein expression and exon 9 PIK3CA activating mutations are independent prognostic factors in TNBC. The efficacy of anti-PI3K targeted therapies needs to be evaluated in this setting.

N-Methyl-N-nitrosourea as a mammary carcinogenic agent

The administration of chemical carcinogens is one of the most commonly used methods to induce tumors in several organs in laboratory animals in order to study oncologic diseases of humans. The carcinogen agent N-methyl-N-nitrosourea (MNU) is the oldest member of the nitroso compounds that has the ability to alkylate DNA. MNU is classified as a complete, potent, and direct alkylating compound. Depending on the animals' species and strain, dose, route, and age at the administration, MNU may induce tumors' development in several organs. The aim of this manuscript was to review MNU as a carcinogenic agent, taking into account that this carcinogen agent has been frequently used in experimental protocols to study the carcinogenesis in several tissues, namely breast, ovary, uterus, prostate, liver, spleen, kidney, stomach, small intestine, colon, hematopoietic system, lung, skin, retina, and urinary bladder. In this paper, we also reviewed the experimental conditions to the chemical induction of tumors in different organs with this carcinogen agent, with a special emphasis in the mammary carcinogenesis.

From bench to bedside: What do we know about hormone receptor-positive and human epidermal growth factor receptor 2-positive breast cancer?

Breast cancer is a heterogeneous disease. Thanks to extensive efforts from research scientists and clinicians, treatment for breast cancer has advanced into the era of targeted medicine. With the use of several well-established biomarkers, such as hormone receptors (HRs) (i.e., estrogen receptor [ER] and progesterone receptor [PgR]) and human epidermal growth factor receptor-2 (HER2), breast cancer patients can be categorized into multiple subgroups with specific targeted treatment strategies. Although therapeutic strategies for HR-positive (HR+) HER2-negative (HER2-) breast cancer and HR-negative (HR-) HER2-positive (HER2+) breast cancer are well-defined, HR+ HER2+ breast cancer is still an overlooked subgroup without tailored therapeutic options. In this review, we have summarized the molecular characteristics, etiology, preclinical tools and therapeutic options for HR+ HER2+ breast cancer. We hope to raise the attention of both the research and the medical community on HR+ HER2+ breast cancer, and to advance patient care for this subtype of disease.

The role of endocytic Rab GTPases in regulation of growth factor signaling and the migration and invasion of tumor cells

Metastasis is characterized pathologically by uncontrolled cell invasion, proliferation, migration and angiogenesis. It is a multistep process that encompasses the modulation of membrane permeability and invasion, cell spreading, cell migration and proliferation of the extracellular matrix, increase in cell adhesion molecules and interaction, decrease in cell attachment and induced survival signals and propagation of nutrient supplies (blood vessels). In cancer, a solid tumor cannot expand and spread without a series of synchronized events. Changes in cell adhesion receptor molecules (e.g., integrins, cadherin-catenins) and protease expressions have been linked to tumor invasion and metastasis. It has also been determined that ligand-growth factor receptor interactions have been associated with cancer development and metastasis via the endocytic pathway. Specifically, growth factors, which include IGF-1 and IGF-2 therapy, have been associated with most if not all of the features of metastasis. In this review, we will revisit some of the key findings on perhaps one of the most important hallmarks of cancer metastasis: cell migration and cell invasion and the role of the endocytic pathway in mediating this phenomenon.

Docosahexaenoic Acid Downregulates EGF-Induced Urokinase Plasminogen Activator and Matrix Metalloproteinase 9 Expression by Inactivating EGFR/ErbB2 Signaling in SK-BR3 Breast Cancer Cells

Urokinase plasminogen activator (uPA) and matrix metalloproteinase 9 (MMP-9) play crucial roles in tumor metastasis. Despite the well-known anticancer role of docosa-hexaenoic acid (DHA), its specific effect on ErbB2-mediated breast cancer metastasis is not fully clarified. In this study, we investigated the effect of DHA on epidermal growth factor (EGF)-induced uPA and MMP-9 activity, expression and cell invasion in SK-BR3 breast cancer cells and the possible mechanisms involved. The results showed that EGF (40 ng/ml) induced uPA and MMP-9 mRNA and protein expression, enzyme activity, and 100 μM DHA significantly inhibited EGF-induced uPA and MMP-9 mRNA, protein expression, enzyme activity, cell migration, and cell invasion. EGF increased protein expression and phosphorylation of EGF receptor (EGFR) and ErbB2 as well as of JNK2, ERK1/2, and Akt, and these changes were attenuated by DHA pretreatment. AG1478, an inhibitor of EGFR, also attenuated EGF-induced activation of EGFR, JNK2, ERK1/2, and Akt. Knocked down ErbB2 expression resulted in a similar inhibition of uPA and MMP-9 expression as noted by DHA and AG1478. Taken together, these results suggest that suppression of EGF-induced metastasis by DHA is likely through an inhibition of EGFR and ErbB2 protein expression and the downstream target uPA and MMP-9 activation in SK-BR3 human breast cancer cells.

Deregulation of the EGFR/PI3K/PTEN/Akt/mTORC1 pathway in breast cancer: possibilities for therapeutic intervention

The EGFR/PI3K/PTEN/Akt/mTORC1/GSK-3 pathway plays prominent roles in malignant transformation, prevention of apoptosis, drug resistance and metastasis. The expression of this pathway is frequently altered in breast cancer due to mutations at or aberrant expression of: HER2, ERalpha, BRCA1, BRCA2, EGFR1, PIK3CA, PTEN, TP53, RB as well as other oncogenes and tumor suppressor genes. In some breast cancer cases, mutations at certain components of this pathway (e.g., PIK3CA) are associated with a better prognosis than breast cancers lacking these mutations. The expression of this pathway and upstream HER2 has been associated with breast cancer initiating cells (CICs) and in some cases resistance to treatment. The anti-diabetes drug metformin can suppress the growth of breast CICs and herceptin-resistant HER2+ cells. This review will discuss the importance of the EGFR/PI3K/PTEN/Akt/mTORC1/GSK-3 pathway primarily in breast cancer but will also include relevant examples from other cancer types. The targeting of this pathway will be discussed as well as clinical trials with novel small molecule inhibitors. The targeting of the hormone receptor, HER2 and EGFR1 in breast cancer will be reviewed in association with suppression of the EGFR/PI3K/PTEN/Akt/mTORC1/GSK-3 pathway.

Roles of signaling pathways in drug resistance, cancer initiating cells and cancer progression and metastasis

The EGFR/PI3K/PTEN/Akt/mTORC pathway plays prominent roles in malignant transformation, prevention of apoptosis, drug resistance, cancer initiating cells (CICs) and metastasis. The expression of this pathway is frequently altered in breast and other cancers due to mutations at or aberrant expression of: HER2, EGFR1, PIK3CA, and PTEN as well as other oncogenes and tumor suppressor genes. miRs and epigenetic mechanisms of gene regulation are also important events which regulate this pathway. In some breast cancer cases, mutations at certain components of this pathway (e.g., PIK3CA) are associated with a better prognosis than breast cancers lacking these mutations. The expression of this pathway has been associated with CICs and in some cases resistance to therapeutics. We will review the effects of activation of the EGFR/PI3K/PTEN/Akt/mTORC pathway primarily in breast cancer and development of drug resistance. The targeting of this pathway and other interacting pathways will be discussed as well as clinical trials with novel small molecule inhibitors as well as established drugs that are used to treat other diseases. In this manuscript, we will discuss an inducible EGFR model (v-ERB-B:ER) and its effects on cell growth, cell cycle progression, activation of signal transduction pathways, prevention of apoptosis in hematopoietic, breast and prostate cancer models.

Positional isomerization of a non-cleavable combi-molecule dramatically altered tumor cell response profile

To potentiate the quinazoline-based inhibitor of the epidermal growth factor receptor (EGFR), a chloroethyl alkylating moiety was appended to its 6-position. This led to molecules with extremely strong EGFR inhibitory potency and anomalously strong DNA-damaging potential. To assess the role of the chloroethyl group on potency, we designed a molecule in which it is shifted to the 7-position where it would be less reactive and away from the cys773 of the EGFR ATP site. The results showed that (i) ZR2009 was 10-fold less potent than its positional isomer ZR2003 in EGFR tyrosine kinase inhibition, (ii) it consistently exhibited significantly weaker antiproliferative potency than ZR2003, (iii) in reversibility assays, while ZR2003 induced sustained inhibition of EGFR phosphorylation, ZR2009 inhibitory activity was partially reversed, and (iv) likewise, ZR2009 significantly lost its activity in short exposure growth inhibitory assays and induced lower levels of DNA damage than ZR2003. Molecular modeling suggested that while the chloroethylamino group in ZR2003 was at 3.5 Å away from Cys773, that of ZR2009 was at 6.3 Å. The results in toto suggest that, while the chloroethyl is a strong alkylating group, its appendage to the 6-position is optimal for DNA damage, sustained EGFR, and growth inhibition.

Signaling pathways in breast cancer: therapeutic targeting of the microenvironment

Breast cancer is the most common cancer in women worldwide. Understanding the biology of this malignant disease is a prerequisite for selecting an appropriate treatment. Cell cycle alterations are seen in many cancers, including breast cancer. Newly popular targeted agents in breast cancer include cyclin dependent kinase inhibitors (CDKIs) which are agents inhibiting the function of cyclin dependent kinases (CDKs) and agents targeting proto-oncogenic signaling pathways like Notch, Wnt, and SHH (Sonic hedgehog). CDKIs are categorized as selective and non-selective inhibitors of CDK. CDKIs have been tried as monotherapy and combination therapy. The CDKI Palbocyclib is now a promising therapeutic in breast cancer. This drug recently entered phase III trial for estrogen receptor (ER) positive breast cancer after showing encouraging results in progression free survival in a phase II trials. The tumor microenvironment is now recognized as a significant factor in cancer treatment response. The tumor microenvironment is increasingly considered as a target for combination therapy of breast cancer. Recent findings in the signaling pathways in breast cancer are herein summarized and discussed. Furthermore, the therapeutic targeting of the microenvironment in breast cancer is also considered.

Phase I dosage finding and pharmacokinetic study of intravenous topotecan and oral erlotinib in adults with refractory solid tumors

PURPOSE

Topotecan is widely used for refractory solid tumors but multi-drug resistance may occur due to tumor expression of ATP-binding cassette (ABC) transporters. Since erlotinib, an inhibitor of the epidermal growth factor receptor, also inhibits several ABC transporters, we performed a phase I study to evaluate the safety, efficacy, and pharmacokinetics of intravenous topotecan given in combination with erlotinib.

METHODS

Patients received 150 mg of oral erlotinib daily and a 30 min intravenous infusion of topotecan on days 1-5 of a 21-day cycle. Dosage escalation of topotecan occurred with a starting dosage of 0.75 mg/m(2). The pharmacokinetics of topotecan was evaluated on day 1 of cycle 1 without erlotinib and on day 1 of cycle 2 or 3 with erlotinib.

RESULTS

Twenty-nine patients were enrolled. The maximum tolerated dosage was determined to be 1.0 mg/m(2). Dose-limiting toxicities included neutropenia and thrombocytopenia. The average duration of treatment was 97 days. Two partial responses were observed. Topotecan clearance and exposure were similar with and without erlotinib.

CONCLUSIONS

The combination of topotecan and erlotinib is tolerable at clinically effective doses. Erlotinib does not affect the disposition of topotecan to a clinically significant extent.

Imaging angiogenesis, inflammation, and metastasis in the tumor microenvironment with magnetic resonance imaging

With the development of new imaging techniques, the potential for probing the molecular, cellular, and structural components of the tumor microenvironment in situ has increased dramatically. A multitude of imaging modalities have been successfully employed to probe different aspects of the tumor microenvironment, including expression of molecules, cell motion, cellularity, vessel permeability, vascular perfusion, metabolic and physiological changes, apoptosis, and inflammation. This chapter focuses on the most recent advances in magnetic resonance imaging methods, which offer a number of advantages over other methodologies, including high spatial resolution and the use of nonionizing radiation, as well as the use of such methods in the context of primary and secondary brain tumors. It also highlights how they can be used to assess the molecular and cellular changes in the tumor microenvironment in response to therapy.

Molecular imaging of EGFR/HER2 cancer biomarkers by protein MRI contrast agents

Epidermal growth factor receptor (EGFR) and HER2 are major prognosis biomarkers and drug targets overexpressed in various types of cancer cells. There is a pressing need to develop MRI contrast agents capable of enhancing the contrast between normal tissues and tumors with high relaxivity, capable of targeting tumors, and with high intratumoral distribution and minimal toxicity. In this review, we first discuss EGFR signaling and its role in tumor progression as a major drug target. We then report our progress in the development of protein contrast agents with significant improvement of both r1 and r2 relaxivities, pharmacokinetics, in vivo retention time, and in vivo dose efficiency. Finally, we report our effort in the development of EGFR-targeted protein contrast agents with the capability to cross the endothelial boundary and with good tissue distribution across the entire tumor mass. The noninvasive capability of MRI to visualize spatially and temporally the intratumoral distribution as well as quantify the levels of EGFR and HER2 would greatly improve our ability to track changes of the biomarkers during tumor progression, monitor treatment efficacy, aid in patient selection, and further develop novel targeted therapies for clinical application.

MicroRNA signatures in hereditary breast cancer

This study aims to identify signatures of miR associated with hereditary, BRCA1 or BRCA2 mutation positive breast cancer (BC), and non-hereditary BC, either sporadic (SBC) or non-informative (BRCAX). Moreover, we search for signatures associated with tumor stage, immunohistochemistry and tumor molecular profile. Twenty formalin fixed paraffin embedded (FFPE) BCs, BRCA1, BRCA2, BRCAX and SBC, five per group were studied. Affymetrix platform miRNA v.3.0 was used to perform miR expression analysis. ER, PR, HER2 and Ki67 protein expression was analyzed by immunohistochemistry. BRCA1, BRCA2 and RASSF1 methylation analysis, AURKA copy number variations, and BRCA1 and BRCA2 deletions, were studied by MLPA. We validated eight of the miR selected by the arrays in 77 BCs by qRT-PCR. The miR profiles associated with tumor features were studied applying the Sparse Partial Least Squares Discriminant Analysis. MiR discrimination capability to distinguish hereditary and non-hereditary BC was analyzed by the discriminant function. With 15 out of 1,733 hsa-miRs, it was possible to differentiate the four groups. BRCA1, BRCA2 and SBC were associated with clusters of hyper-expressed miRs, and BRCAX with hypo-expressed miRs. Hsa-miR-4417 and hsa-miR-423-3p expressions (included among the eight validated miRs) differentiated 70.1 % of hereditary and non-hereditary BCs. We found miR profiles associated with tumor features like node involvement, histological grade, ER, PR and HER2 expression. Regarding molecular parameters, we only found a weak association of miRs in BC harboring losses in AURKA. We conclude that array miR expression profiles can differentiate the four study groups using FFPE BC. However, miRs expression estimated by qRT-PCR differentiates only hereditary and non-inherited BCs. The miR expression array is a simple and rapid approach that could be useful to facilitate the identification of those SBC carrying genetic or epigenetic changes in BRCA genes responsible of BRCA-like phenotype. These patients could benefit from the treatment with PARP inhibitors.

IC-4, a new irreversible EGFR inhibitor, exhibits prominent anti-tumor and anti-angiogenesis activities

Accumulating evidence suggested that the irreversible tyrosine kinase inhibitors (TKIs) have potential to override the acquired resistance to target-based therapies. Herein, we reported IC-4 as a novel irreversible TKI for epidermal growth factor receptor (EGFR). IC-4 potentially suppressed proliferation, induced apoptosis and a G2/M cell cycle arrest in breast cancer cells, correlating with inhibition of EGF-induced EGFR activation, but independent of DNA damage. In addition, IC-4 exhibited anti-angiogenetic activities both in vitro and in vivo. It suppressed cell viability and proliferation induced by various growth factors in human umbilical vein endothelial cells (HUVECs). IC-4 also inhibited HUVECs migration and tube formation. In transgenic zebrafish embryo model, IC-4 was shown to suppress formation of intersegmental vessel and development of subintestinal vessels. Taken together, these results demonstrated that IC-4 is a new irreversible EGFR-TKI, exhibiting potent anti-breast cancer and anti-angiogenetic effects.

c-MYC-regulated miR-23a/24-2/27a cluster promotes mammary carcinoma cell invasion and hepatic metastasis by targeting Sprouty2

Emerging evidence indicates that the miR-23a/24-2/27a cluster may possess a causal role in mammary tumorigenesis and function as a novel class of oncogenes. However, the regulatory mechanism of the miR-23a/24-2/27a cluster in mammary carcinoma cell invasion and migration is still largely unknown. We observed that the expression levels of miR-23a, miR-24-2 and miR-27a were significantly higher in breast cancer with lymph node metastasis, compared with that from patients without lymph node metastasis or normal tissue. Forced expression of the miR-23a/24-2/27a cluster promoted mammary carcinoma cell migration, invasion, and hepatic metastasis, through targeting Sprouty2 (SPRY2) and consequent activation of p44/42 MAPK. Epidermal growth factor induced the expression of the transcription factor c-MYC, which promoted the expression of mature miR-23a, miR-24-2, and miR-27a and subsequently decreased expression of SPRY2 and activated p44/42 MAPK to promote mammary carcinoma cell migration and invasion. We therefore suggest a novel link between epidermal growth factor and the miR-23a/24-2/27a cluster via the regulation of c-MYC, providing the potential for the miR-23a/24-2/27a cluster to be used as biomarker in the diagnosis and/or treatment of breast cancer.

EGFR Gene Amplification and Protein Expression in Invasive Ductal Carcinoma of the Breast

Background

The epidermal growth factor receptor (EGFR) is a surrogate marker for basal-like breast cancer. A recent study suggested that EGFR may be used as a target for breast cancer treatment.

Methods

A total of 706 invasive ductal carcinomas (IDC) of the breast were immunophenotyped, and 82 cases with EGFR protein expression were studied for EGFR gene amplification.

Results

EGFR protein was expressed in 121 of 706 IDCs (17.1%); 5.9% were of luminal type, 25.3% of epidermal growth factor receptor 2 (HER-2) type, and 79.3% of basal-like tumors. EGFR gene amplification and high polysomy (fluorescent in situ hybridization [FISH]-positive) were found in 18 of 82 cases (22.0%); 41.2% of the HER-2⁺, EGFR⁺, cytokeratin 5/6^- (CK5/6^-) group, 11.2% of the HER-2^-, EGFR⁺, CK5/6^- group, and 19.1% of the HER-2^-, EGFR⁺, CK5/6⁺ group. FISH-positive cases were detected in 8.3% of the EGFR protein 1⁺ expression cases, 15.9% of 2⁺ expression cases, and 38.5% of 3⁺ expression cases. In group 2, the tumors had a high Ki-67 labeling (>60%), but the patients showed better disease-free survival than those with tumors that co-expressed HER-2 or CK5/6.

Conclusions

EGFR-directed therapy can be considered in breast cancer patients with EGFR protein overexpression and gene amplification, and its therapeutic implication should be determined in HER-2 type breast cancer patients.

HER2/neu gene amplification and protein overexpression in gastric and gastroesophageal junction adenocarcinoma: a review of histopathology, diagnostic testing, and clinical implications

Amplification of the human epidermal growth factor receptor 2/neu (HER2/neu) gene and overexpression of the HER2 protein (HER2) have been shown to occur in gastric and gastroesophageal junction adenocarcinoma in a number of studies. With a dismal survival rate, patients with these cancers stand to benefit from the identification of possible molecular targets such as HER2 for both prognostic and therapeutic purposes. Although these and other carcinomas that overexpress HER2 may have a poorer prognosis and exhibit resistance to conventional chemotherapy, they have also recently been shown to respond to targeted therapy with the anti-HER2 antibody trastuzumab. Here, we briefly review the molecular biology, histopathology, diagnostic techniques, and interpretation, as well as the clinical implications, of HER2 amplification/overexpression in gastric and gastroesophageal adenocarcinoma.

N-Terminal labeling of filamentous phage to create cancer marker imaging agents

We report a convenient new technique for the labeling of filamentous phage capsid proteins. Previous reports have shown that phage coat protein residues can be modified, but the lack of chemically distinct amino acids in the coat protein sequences makes it difficult to attach high levels of synthetic molecules without altering the binding capabilities of the phage. To modify the phage with polymer chains, imaging groups, and other molecules, we have developed chemistry to convert the N-terminal amines of the ~4200 coat proteins into ketone groups. These sites can then serve as chemospecific handles for the attachment of alkoxyamine groups through oxime formation. Specifically, we demonstrate the attachment of fluorophores and up to 3000 molecules of 2 kDa poly(ethylene glycol) (PEG2k) to each of the phage capsids without significantly affecting the binding of phage-displayed antibody fragments to EGFR and HER2 (two important epidermal growth factor receptors). We also demonstrate the utility of the modified phage for the characterization of breast cancer cells using multicolor fluorescence microscopy. Due to the widespread use of filamentous phage as display platforms for peptide and protein evolution, we envision that the ability to attach large numbers of synthetic functional groups to their coat proteins will be of significant value to the biological and materials communities.

Downregulation of galectin-3 by EGF mediates the apoptosis of HepG2 cells

Epidermal growth factor (EGF) in high concentrations induces apoptosis of the tumor cells which express high levels of epidermal growth factor receptor. However, the precise mechanism for this induction is not clear. Galectin-3 is the most probable candidate for mediating this effect, as it is known to induce anti-apoptotic activity in a variety of tumor cells exposed to diverse apoptotic stimuli. In this study, we determined whether galectin-3 plays a role in high concentrations of EGF-induced apoptosis of HepG2 cells. We found that EGF in high concentrations led to the growth inhibition of HepG2 cells, which were associated with promotion of cell death. High concentrations of EGF suppressed cytoplasmic expression of galectin-3. Moreover, we demonstrated overexpression of galectin-3 could reduce EGF-induced apoptosis in HepG2 cells. Our study demonstrated for the first time that downregulation of cytoplasmic galectin-3 was essential for high concentrations of EGF-induced apoptosis in HepG2 cells.

MicroRNA-regulated gene networks during mammary cell differentiation are associated with breast cancer

MicroRNAs (miRNAs) play pivotal roles in stem cell biology, differentiation and oncogenesis and are of high interest as potential breast cancer therapeutics. However, their expression and function during normal mammary differentiation and in breast cancer remain to be elucidated. In order to identify which miRNAs are involved in mammary differentiation, we thoroughly investigated miRNA expression during functional differentiation of undifferentiated, stem cell-like, murine mammary cells using two different large-scale approaches followed by qPCR. Significant changes in expression of 21 miRNAs were observed in repeated rounds of mammary cell differentiation. The majority, including the miR-200 family and known tumor suppressor miRNAs, was upregulated during differentiation. Only four miRNAs, including oncomiR miR-17, were downregulated. Pathway analysis indicated complex interactions between regulated miRNA clusters and major pathways involved in differentiation, proliferation and stem cell maintenance. Comparisons with human breast cancer tumors showed the gene profile from the undifferentiated, stem-like stage clustered with that of poor-prognosis breast cancer. A common nominator in these groups was the E2F pathway, which was overrepresented among genes targeted by the differentiation-induced miRNAs. A subset of miRNAs could further discriminate between human non-cancer and breast cancer cell lines, and miR-200a/miR-200b, miR-146b and miR-148a were specifically downregulated in triple-negative breast cancer cells. We show that miR-200a/miR-200b can inhibit epithelial-mesenchymal transition (EMT)-characteristic morphological changes in undifferentiated, non-tumorigenic mammary cells. Our studies propose EphA2 as a novel and important target gene for miR-200a. In conclusion, we present evidentiary data on how miRNAs are involved in mammary cell differentiation and indicate their related roles in breast cancer.

MYC and Breast Cancer

MYC is a key regulator of cell growth, proliferation, metabolism, differentiation, and apoptosis. MYC deregulation contributes to breast cancer development and progression and is associated with poor outcomes. Multiple mechanisms are involved in MYC deregulation in breast cancer, including gene amplification, transcriptional regulation, and mRNA and protein stabilization, which correlate with loss of tumor suppressors and activation of oncogenic pathways. The heterogeneity in breast cancer is increasingly recognized. Breast cancer has been classified into 5 or more subtypes based on gene expression profiles, and each subtype has distinct biological features and clinical outcomes. Among these subtypes, basal-like tumor is associated with a poor prognosis and has a lack of therapeutic targets. MYC is overexpressed in the basal-like subtype and may serve as a target for this aggressive subtype of breast cancer. Tumor suppressor BRCA1 inhibits MYC's transcriptional and transforming activity. Loss of BRCA1 with MYC overexpression leads to the development of breast cancer-especially, basal-like breast cancer. As a downstream effector of estrogen receptor and epidermal growth factor receptor family pathways, MYC may contribute to resistance to adjuvant therapy. Targeting MYC-regulated pathways in combination with inhibitors of other oncogenic pathways may provide a promising therapeutic strategy for breast cancer, the basal-like subtype in particular.

Upregulated expression of indoleamine 2, 3-dioxygenase in primary breast cancer correlates with increase of infiltrated regulatory T cells in situ and lymph node metastasis

IDO has been reported to induce immunotolerance and promote metastasis in solid malignancy, but the mechanisms involved were not fully understood. In this study, the expression of IDO in primary breast cancer was examined and the correlation between the expression levels of IDO and the densities of Foxp3⁺ Tregs in situ was studied. The IDO stably-expressing CHO cells(IDO/CHO) were generated to evaluate the induction of Foxp3⁺ Tregs after coculturing with CD3⁺ T cells in vitro. The IDO expression in cancer was higher than that in benign diseases both at RNA and protein levels. The IDO expression was significantly upregulated in tumors of more advanced stages and with more extensive lymph node metastasis, and displayed positive linear correlation with the density of Foxp3⁺ Tregs. We further demonstrated that CD4⁺CD25⁺CD127⁻ Tregs could be amplified by coculturing CD3⁺ T cells with IDO/CHO cells in vitro which displayed increasing Foxp3 expression both at mRNA and protein levels. Our results implied that up-regulation of IDO in primary breast cancer may inhibit local immune surveillance and promote metastasis by favoring development and infiltration of Foxp3⁺ Tregs in the tumor microenvironment.

Comparison of increased aromatase versus ERα in the generation of mammary hyperplasia and cancer

Factors associated with increased estrogen synthesis increase breast cancer risk. Increased aromatase and estrogen receptor α (ERα) in both normal epithelium and ductal carcinoma in situ lesions are found in conjunction with breast cancer, leading to the idea that altered estrogen signaling pathways predispose the mammary gland to cancer development. Here, we developed a transgenic mouse that conditionally expresses aromatase in the mammary gland, and used it along with a deregulated ERα expression model to investigate the molecular pathways involved in the development of mammary gland preneoplasia and carcinoma. Both increased ERα and aromatase expression led to the development of preneoplasia, but increased preneoplasia, in addition to carcinoma, was found in aromatase overexpressing mice. Increased prevalence of mammary pathologic changes in mice expressing aromatase correlated with increased cyclin E and cyclin-dependent kinase 2 expression. Gain of both ERα and aromatase increased expression of ERα and progesterone receptor, but aromatase produced a higher increase than ERα, accompanied by higher levels of downstream target genes Ccnd1, Myc, and Tnfsf11. In summary, whereas gain of both ERα and aromatase activate abnormal growth pathways in the mammary gland, aromatase induced a wider range of abnormalities that was associated with a higher prevalence of mammary preneoplasia and cancer progression.

Up-regulation of kin17 is essential for proliferation of breast cancer

Background

Kin17 is ubiquitously expressed at low levels in human tissue and participates in DNA replication, DNA repair and cell cycle control. Breast cancer cells are characterized by enabling replicative immortality and accumulated DNA damage. However, whether kin17 contributes to breast carcinogenesis remains unknown.

Methodology/Principal Findings

In this study, we show for the first time that kin17 is an important molecule related to breast cancer. Our results show that kin17 expression was markedly increased in clinical breast tumors and was associated with tumor grade, Ki-67 expression, p53 mutation status and progesterone receptor expression, which were assessed in a clinicopathologic characteristics review. Knockdown of kin17 inhibited DNA replication and repair, blocked cell cycle progression and inhibited anchorage-independent growth, while increasing sensitivity to chemotherapy in breast cancer cells. Moreover, kin17 silencing decreased EGF-stimulated cell growth. Furthermore, overexpression of kin17 promoted DNA replication and cell proliferation in MCF-10A.

Conclusions/Significance

Our findings indicate that up-regulation of kin17 is strongly associated with cellular proliferation, DNA replication, DNA damage response and breast cancer development. The increased level of kin17 was not only a consequence of immortalization but also associated with tumorigenesis. Therefore, kin17 could be a novel therapeutic target for inhibiting cell growth in breast cancer.

Pivotal role of reduced let-7g expression in breast cancer invasion and metastasis

Screening of the entire let-7 family of microRNAs (miRNA) by in situ hybridization identified let-7g as the only member, the diminished expression of which was significantly associated with lymph node metastasis and poor survival in breast cancer patients. Abrogation of let-7g expression in otherwise nonmetastatic mammary carcinoma cells elicited rapid metastasis from the orthotopic location, through preferential targets, Grb2-associated binding protein 2 (GAB2) and fibronectin 1 (FN1), and consequent activation of p44/42 mitogen-activated protein kinase (MAPK) and specific matrix metalloproteinases. Treatment with estrogen or epidermal growth factor specifically reduced the expression of mature let-7g through activation of p44/42 MAPK and subsequently stimulated expression of GAB2 and FN1, which, in turn, promoted tumor invasion. We thus identify let-7g as a unique member of the let-7 miRNA family that can serve as a prognostic biomarker in breast cancer and also propose a paradigm used by specific signaling molecules via let-7g to cooperatively promote breast cancer invasion and metastasis. Thus, let-7 family members neither possess equivalent clinicopathologic correlation nor function in breast cancer.