The molecular pathology of breast cancer progression

USP41 promotes breast cancer via regulating RACK1

Background

Breast cancer (BC) is the most common cancer diagnosed among women and is the second leading cause of cancer death. It is of great significance to explore potential candidate targets for BC.

Methods

The expression of ubiquitin-specific protease 41 (USP41) and its prognosis prediction function was firstly evaluated by TCGA database analysis. Using BC cell lines and specimens from 10 patients with primary BC, the upregulation of USP41 in BC was ensured. By USP41 overexpression or knockdown, its function was studied by cell function assays, small interfering RNA (siRNA), western blot, mass spectrometry, and flow cytometry. The potential mechanism of USP41 was explored via Co-Immunoprecipitation mass spectrometry, and western blot.

Results

TCGA database analysis revealed that in metastatic BC, USP41 expression was upregulated and negatively correlated with BC prognosis. In BC cancer cells and cancer specimens, USP41 was also upregulated. Overexpression of USP41 greatly enhanced BC colony-forming ability, proliferation, and migration. In contrast, USP41 knockdown significantly inhibited BC colony-forming ability, proliferation, and migration. Moreover, Co-Immunoprecipitation mass spectrometry results indicated that USP41 could interact with RACK1. USP41 promoted the protein expression of RACK1. The expression of RACK1 in BC tissues was upregulated. Knockdown of RACK1 inhibited cell growth and migration, and reversed the oncogenic function of USP41 in BC cells.

Conclusions

USP41 can be a potential therapeutic target against BC via RACK1.

Molecular markers of risk of subsequent invasive breast cancer in women with ductal carcinoma in situ: protocol for a population-based cohort study

INTRODUCTION

Ductal carcinoma in situ (DCIS) of the breast is a non-obligate precursor of invasive breast cancer (IBC). Many DCIS patients are either undertreated or overtreated. The overarching goal of the study described here is to facilitate detection of patients with DCIS at risk of IBC development. Here, we propose to use risk factor data and formalin-fixed paraffin-embedded (FFPE) DCIS tissue from a large, ethnically diverse, population-based cohort of 8175 women with a first diagnosis of DCIS and followed for subsequent IBC to: identify/validate miRNA expression changes in DCIS tissue associated with risk of subsequent IBC; evaluate ipsilateral IBC risk in association with two previously identified marker sets (triple immunopositivity for p16, COX-2, Ki67; Oncotype DX Breast DCIS score); examine the association of risk factor data with IBC risk.

METHODS AND ANALYSIS

We are conducting a series of case-control studies nested within the cohort. Cases are women with DCIS who developed subsequent IBC; controls (2/case) are matched to cases on calendar year of and age at DCIS diagnosis. We project 485 cases/970 controls in the aim focused on risk factors. We estimate obtaining FFPE tissue for 320 cases/640 controls for the aim focused on miRNAs; of these, 173 cases/346 controls will be included in the aim focused on p16, COX-2 and Ki67 immunopositivity, and of the latter, 156 case-control pairs will be included in the aim focused on the Oncotype DX Breast DCIS score®. Multivariate conditional logistic regression will be used for statistical analyses.

ETHICS AND DISSEMINATION

Ethics approval was obtained from the Institutional Review Boards of Albert Einstein College of Medicine (IRB 2014-3611), Kaiser Permanente Colorado, Kaiser Permanente Hawaii, Henry Ford Health System, Mayo Clinic, Marshfield Clinic Research Institute and Hackensack Meridian Health, and from Lifespan Research Protection Office. The study results will be presented at meetings and published in peer-reviewed journals.

Novel genomic alteration in superficial esophageal squamous cell neoplasms in non-smoker non-drinker females

Alcohol consumption and smoking pose a significant risk for esophageal squamous cell neoplasia (ESCN) development in males; however, ESCN is often diagnosed in non-drinking and non-smoking females. The mechanisms underlying these differences remain elusive, and understanding them can potentially identify novel pathways involved in ESCN development. We performed short-read sequencing to identify somatic variants on a cancer panel targeting 409 genes using DNA extracted from the superficial squamous cell carcinoma (ESCC) tissues and adjacent non-neoplastic epithelium (NE), and immunohistochemical staining of the protein encoded by the target gene. All male patients (n = 117) were drinkers or smokers, whereas 45% of the female patients (n = 33) were not. Somatic variants were compared among three age-matched groups: 13 female ESCC patients with smoking and drinking habits (known-risk group, F-KR), 13 female ESCC patients without these habits (unknown-risk group, F-UR), and 27 males with ESCC and smoking and drinking habits (M-KR). In the NE, the frequencies of CDKN2A variants were significantly higher in F-UR than in F-KR and M-KR. In both ESCC and NE, p14ARF was significantly overexpressed in F-UR than in the other groups. In conclusion, CDKN2A might be important in ESCC development, independent of known risk factors.

Estrogen-regulated AGR3 activates the estrogen receptor signaling pathway to promote tamoxifen resistance in breast cancer

PURPOSE

Anterior gradient 3 (AGR3) is associated with breast cancer progression, but its relationship with estrogen and tamoxifen resistance in breast cancer is still unclear. This study was designed to investigate the correlation of ARG3 and estrogen as well as the roles of ARG3 in tamoxifen resistance in breast cancer.

METHODS

Online database including GEPIA, UALCAN, and TCGA and rVista predictive tool were applied to analyze the expression patterns of AGR3 and its relationship with estrogen receptor 1. AGR3 knockdown and overexpression cell models were constructed. Luciferase reporter assay and ChIP were performed to investigate intermolecular interactions. Western blotting and qPCR were applied to assess targets at mRNA and protein levels, respectively. Cell counting and MTT assay were applied to determine the cell proliferation.

RESULTS

An elevation of AGR3 was observed in patients with breast cancer, especially in the patients with estrogen receptor (ER)-positive breast cancer. The TCGA dataset and in vitro data supported that AGR3 was positively correlated to ER. Further results demonstrated that ER protein bound to AGR3 promoter sites. AGR3 expression exhibited a positive correlation to cell viability. Besides, AGR3 promoted tamoxifen resistance in breast cancer.

CONCLUSION

AGR3 is associated with estrogen and promotes tamoxifen resistance in breast cancer.

HER2 Expression in Circulating Tumour Cells Isolated from Metastatic Breast Cancer Patients Using a Size-Based Microfluidic Device

HER2 is a prognostic and predictive biomarker in breast cancer, normally assessed in tumour biopsy and used to guide treatment choices. Circulating tumour cells (CTCs) escape the primary tumour and enter the bloodstream, exhibiting great metastatic potential and representing a real-time snapshot of the tumour burden. Liquid biopsy offers the unique opportunity for low invasive sampling in cancer patients and holds the potential to provide valuable information for the clinical management of cancer patients. This study assesses the performance of the RUBYchip™, a microfluidic system for CTC capture based on cell size and deformability, and compares it with the only FDA-approved technology for CTC enumeration, CellSearch®. After optimising device performance, 30 whole blood samples from metastatic breast cancer patients were processed with both technologies. The expression of HER2 was assessed in isolated CTCs and compared to tissue biopsy. Results show that the RUBYchipTM was able to isolate CTCs with higher efficiency than CellSearch®, up to 10 times more, averaging all samples. An accurate evaluation of different CTC subpopulations, including HER2+ CTCs, was provided. Liquid biopsy through the use of the RUBYchipTM in the clinic can overcome the limitations of histological testing and evaluate HER2 status in patients in real-time, helping to tailor treatment during disease evolution.

Epithelial p53 Status Modifies Stromal-Epithelial Interactions During Basal-Like Breast Carcinogenesis

Basal-like breast cancers (BBC) exhibit subtype-specific phenotypic and transcriptional responses to stroma, but little research has addressed how stromal-epithelial interactions evolve during early BBC carcinogenesis. It is also unclear how common genetic defects, such as p53 mutations, modify these stromal-epithelial interactions. To address these knowledge gaps, we leveraged the MCF10 progression series of breast cell lines (MCF10A, MCF10AT1, and MCF10DCIS) to develop a longitudinal, tissue-contextualized model of p53-deficient, pre-malignant breast. Acinus asphericity, a morphogenetic correlate of cell invasive potential, was quantified with optical coherence tomography imaging, and gene expression microarrays were performed to identify transcriptional changes associated with p53 depletion and stromal context. Co-culture with stromal fibroblasts significantly increased the asphericity of acini derived from all three p53-deficient, but not p53-sufficient, cell lines, and was associated with the upregulation of 38 genes. When considered as a multigene score, these genes were upregulated in co-culture models of invasive BBC with increasing stromal content, as well as in basal-like relative to luminal breast cancers in two large human datasets. Taken together, stromal-epithelial interactions during early BBC carcinogenesis are dependent upon epithelial p53 status, and may play important roles in the acquisition of an invasive morphologic phenotype.

Sprouty4 negatively regulates ERK/MAPK signaling and the transition from in situ to invasive breast ductal carcinoma

Breast ductal carcinoma in situ (DCIS) is a non-obligate precursor of invasive ductal carcinoma (IDC). It is still unclear which DCIS will become invasive and which will remain indolent. Patients often receive surgery and radiotherapy, but this early intervention has not produced substantial decreases in late-stage disease. Sprouty proteins are important regulators of ERK/MAPK signaling and have been studied in various cancers. We hypothesized that Sprouty4 is an endogenous inhibitor of ERK/MAPK signaling and that its loss/reduced expression is a mechanism by which DCIS lesions progress toward IDC, including triple-negative disease. Using immunohistochemistry, we found reduced Sprouty4 expression in IDC patient samples compared to DCIS, and that ERK/MAPK phosphorylation had an inverse relationship to Sprouty4 expression. These observations were reproduced using a 3D culture model of disease progression. Knockdown of Sprouty4 in MCF10.DCIS cells increased ERK/MAPK phosphorylation as well as their invasive capability, while overexpression of Sprouty4 in MCF10.CA1d IDC cells reduced ERK/MAPK phosphorylation, invasion, and the aggressive phenotype exhibited by these cells. Immunofluorescence experiments revealed reorganization of the actin cytoskeleton and relocation of E-cadherin back to the cell surface, consistent with the restoration of adherens junctions. To determine whether these effects were due to changes in ERK/MAPK signaling, MEK1/2 was pharmacologically inhibited in IDC cells. Nanomolar concentrations of MEK162/binimetinib restored an epithelial-like phenotype and reduced pericellular proteolysis, similar to Sprouty4 overexpression. From these data we conclude that Sprouty4 acts to control ERK/MAPK signaling in DCIS, thus limiting the progression of these premalignant breast lesions.

High-risk lesions of the breast: concurrent diagnostic tools and management recommendations

Breast lesions with uncertain malignant behavior, also known as high-risk or B3 lesions, are composed of a variety of pathologies with differing risks of associated malignancy. While open excision was previously preferred to manage all high-risk lesions, tailored management has been increasingly favored to reduce overtreatment and spare patients from unnecessary anxiety or high healthcare costs associated with surgical excision. The purpose of this work is to provide the reader with an accurate overview focused on the main high-risk lesions of the breast: atypical intraductal epithelial proliferation (atypical ductal hyperplasia), lobular neoplasia (including the subcategories lobular carcinoma in situ and atypical lobular hyperplasia), flat epithelial atypia, radial scar and papillary lesions, and phyllodes tumor. Beyond merely presenting the radiological aspects of these lesions and the recent literature, information about their potential upgrade rates is discussed in order to provide a useful guide for appropriate clinical management while avoiding the risks of unnecessary surgical intervention (overtreatment).

Review: Multiplexed profiling of biomarkers in extracellular vesicles for cancer diagnosis and therapy monitoring

Extracellular vesicles (EVs) are nanoscale vesicles secreted by normal and pathological cells. The types and levels of surface proteins and internal nucleic acids in EVs are closely related to their original cells, tumor occurrence, and development. Thus, the sensitive and accurate detection of EV biomarkers is a reliable approach for noninvasive disease diagnosis and treatment response monitoring. However, the purification and molecular profiling of these EVs are technically challenging. Much effort has been dedicated to developing new methods for the detection of multiple EV biomarkers. In this review, we summarize the recent progress in EV protein and nucleic acid biomarker analysis. Additionally, we systematically discuss the advantages of multiplexed EV biomarker detection for accurate cancer diagnosis, therapy monitoring, and cancer screening. This article aims to present an overview of all kinds of analytical technologies for assessing EVs and their applications in clinical settings.

Molecular fingerprint of precancerous lesions in breast atypical hyperplasia

OBJECTIVE

To identify atypical hyperplasia (AH) of the breast by shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS), and to explore the molecular fingerprinting characteristics of breast AH.

METHODS

Breast hyperplasia was studied in 11 hospitals across China from January 2015 to December 2016. All patients completed questionnaires on women's health. The differences between patients with and without breast AH were compared. AH breast lesions were detected by Raman spectroscopy followed by the SHINERS technique.

RESULTS

There were no significant differences in clinical features and risk-related factors between patients with breast AH (n = 37) and the control group (n = 2576). Fifteen cases of breast AH lesions were detected by Raman spectroscopy. The main different Raman peaks in patients with AH appeared at 880, 1001, 1086, 1156, 1260, and 1610 cm^-1, attributed to the different vibrational modes of nucleic acids, β-carotene, and proteins. Shell-isolated nanoparticles had different enhancement effects on the nucleic acid, protein, and lipid components in AH.

CONCLUSION

Raman spectroscopy can detect characteristic molecular changes in breast AH lesions, and may thus be useful for the non-invasive early diagnosis and for investigating the mechanism of tumorigenesis in patients with breast AH.

Tumor-associated autoantibodies from mouse breast cancer models are found in serum of breast cancer patients

B cell responses to tumor antigens occur early in breast tumors and may identify immunogenic drivers of tumorigenesis. Sixty-two candidate antigens were identified prior to palpable tumor development in TgMMTV-neu and C3(1)Tag transgenic mouse mammary tumor models. Five antigens (VPS35, ARPC2, SERBP1, KRT8, and PDIA6) were selected because their decreased expression decreased survival in human HER2 positive and triple negative cell lines in a siRNA screen. Vaccination with antigen-specific epitopes, conserved between mouse and human, inhibited tumor growth in both transgenic mouse models. Increased IgG autoantibodies to the antigens were elevated in serum from women with ductal carcinoma in situ (DCIS) and invasive breast cancer (IBC). The autoantibodies differentiated women with DCIS from control with AUC 0.93 (95% CI 0.88-0.98, p < 0.0001). The tumor antigens identified early in the development of breast cancer in mouse mammary tumor models were conserved in human disease, and potentially identify early diagnostic markers in human breast tumors.

Machine learning-based image analysis for accelerating the diagnosis of complicated preneoplastic and neoplastic ductal lesions in breast biopsy tissues

PURPOSE

Diagnosis of breast preneoplastic and neoplastic lesions is difficult due to their similar morphology in breast biopsy specimens. To diagnose these lesions, pathologists perform immunohistochemical analysis and consult with expert breast pathologists. These additional examinations are time-consuming and expensive. Artificial intelligence (AI)-based image analysis has recently improved, and may help in ordinal pathological diagnosis. Here, we showed the significance of machine learning-based image analysis of breast preneoplastic and neoplastic lesions for facilitating high-throughput diagnosis.

METHODS

Images were obtained from normal mammary glands, hyperplastic lesions, preneoplastic lesions and neoplastic lesions, such as usual ductal hyperplasia (UDH), columnar cell lesion (CCL), ductal carcinoma in situ (DCIS), and DCIS with comedo necrosis (comedo DCIS) in breast biopsy specimens. The original enhanced convoluted neural network (CNN) system was used for analyzing the pathological images.

RESULTS

The AI-based image analysis provided the following area under the curve values (AUC): normal lesion versus DCIS, 0.9902; DCIS versus comedo DCIS, 0.9942; normal lesion versus CCL, 0.9786; and UDH versus DCIS, 1.000. Multiple comparison analysis showed precision and recall scores similar to those of single comparison analysis. Based on the gradient-weighted class activation mapping (Grad-CAM) used to visualize the important regions reflecting the result of CNN analysis, the ratio of stromal tissue in the whole weighted area was significantly higher in UDH and CCL than that in DCIS.

CONCLUSIONS

These analyses may provide a more accurate and rapid pathological diagnosis of patients. Moreover, Grad-CAM identifies uncharted important histological characteristics for newer pathological findings and targets of research for understanding diseases.

Drug Resistance in Metastatic Breast Cancer: Tumor Targeted Nanomedicine to the Rescue

Breast cancer, specifically metastatic breast, is a leading cause of morbidity and mortality in women. This is mainly due to relapse and reoccurrence of tumor. The primary reason for cancer relapse is the development of multidrug resistance (MDR) hampering the treatment and prognosis. MDR can occur due to a multitude of molecular events, including increased expression of efflux transporters such as P-gp, BCRP, or MRP1; epithelial to mesenchymal transition; and resistance development in breast cancer stem cells. Excessive dose dumping in chemotherapy can cause intrinsic anti-cancer MDR to appear prior to chemotherapy and after the treatment. Hence, novel targeted nanomedicines encapsulating chemotherapeutics and gene therapy products may assist to overcome cancer drug resistance. Targeted nanomedicines offer innovative strategies to overcome the limitations of conventional chemotherapy while permitting enhanced selectivity to cancer cells. Targeted nanotheranostics permit targeted drug release, precise breast cancer diagnosis, and importantly, the ability to overcome MDR. The article discusses various nanomedicines designed to selectively target breast cancer, triple negative breast cancer, and breast cancer stem cells. In addition, the review discusses recent approaches, including combination nanoparticles (NPs), theranostic NPs, and stimuli sensitive or “smart” NPs. Recent innovations in microRNA NPs and personalized medicine NPs are also discussed. Future perspective research for complex targeted and multi-stage responsive nanomedicines for metastatic breast cancer is discussed.

Genomic profiling reveals heterogeneous populations of ductal carcinoma in situ of the breast

In a substantial number of patients, ductal carcinoma in situ (DCIS) of the breast will never progress to invasive ductal carcinoma, and these patients are often overtreated under the current clinical criteria. Although various candidate markers are available, relevant markers for delineating risk categories have not yet been established. In this study, we analyzed the clinical characteristics of 431 patients with DCIS and performed whole-exome sequencing analysis in a 21-patient discovery cohort and targeted deep sequencing analysis in a 72-patient validation cohort. We determined that age <45 years, HER2 amplification, and GATA3 mutation are possible indicators of relapse. PIK3CA mutation negativity and PgR negativity were also suggested to be risk factors. Spatial transcriptome analysis further revealed that GATA3 dysfunction upregulates epithelial-to-mesenchymal transition and angiogenesis, followed by PgR downregulation. These results reveal the existence of heterogeneous cell populations in DCIS and provide predictive markers for classifying DCIS and optimizing treatment.

Satoi Nagasawa and Yuta Kuze et al. report a multi-omic analysis of ductal carcinoma in situ (DCIS) of the breast, including whole-exome, single-cell, and spatial transcriptome sequencing. They find that for patients under 45 years of age, HER2 amplification and GATA3 mutation are associated with higher risk of relapse, suggesting they could be used as predictive markers when deciding on a treatment course.

Comprehensive Review of Molecular Mechanisms and Clinical Features of Invasive Lobular Cancer

Invasive lobular carcinoma (ILC) accounts for 10% to 15% of breast cancers in the United States, 80% of which are estrogen receptor (ER)-positive, with an unusual metastatic pattern of spread to sites such as the serosa, meninges, and ovaries, among others. Lobular cancer presents significant challenges in detection and clinical management given its multifocality and multicentricity at presentation. Despite the unique features of ILC, it is often lumped with hormone receptor-positive invasive ductal cancers (IDC); consequently, ILC screening, treatment, and follow-up strategies are largely based on data from IDC. Despite both being treated as ER-positive breast cancer, querying the Cancer Genome Atlas database shows distinctive molecular aberrations in ILC compared with IDC, such as E-cadherin loss (66% vs. 3%), FOXA1 mutations (7% vs. 2%), and GATA3 mutations (5% vs. 20%). Moreover, compared with patients with IDC, patients with ILC are less likely to undergo breast-conserving surgery, with lower rates of complete response following therapy as these tumors are less chemosensitive. Taken together, this suggests that ILC is biologically distinct, which may influence tumorigenesis and therapeutic strategies. Long-term survival and clinical outcomes in patients with ILC are worse than in stage- and grade-matched patients with IDC; therefore, nuanced criteria are needed to better define treatment goals and protocols tailored to ILC's unique biology. This comprehensive review highlights the histologic and clinicopathologic features that distinguish ILC from IDC, with an in-depth discussion of ILC's molecular alterations and biomarkers, clinical trials and treatment strategies, and future targets for therapy. IMPLICATIONS FOR PRACTICE: The majority of invasive lobular breast cancers (ILCs) are hormone receptor (HR)-positive and low grade. Clinically, ILC is treated similar to HR-positive invasive ductal cancer (IDC). However, ILC differs distinctly from IDC in its clinicopathologic characteristics and molecular alterations. ILC also differs in response to systemic therapy, with studies showing ILC as less sensitive to chemotherapy. Patients with ILC have worse clinical outcomes with late recurrences. Despite these differences, clinical trials treat HR-positive breast cancers as a single disease, and there is an unmet need for studies addressing the unique challenges faced by patients diagnosed with ILC.

Flat epithelial atypia: What the radiologist needs to know in 2021

The World Health Organization defines flat epithelial atypia (FEA), as a "presumably neoplastic intraductal alteration characterized by the replacement of native epithelial cells by a single layer or three to five layers of mildly atypical cells.". In this article, we will review FEA and compare its characteristics and differences with other atypical high-risk breast lesions. In addition, the imaging appearance of FEA will be described. Finally, we will discuss current outcomes and provide an update on its management based on the last recommendations.

Modeling molecular development of breast cancer in canine mammary tumors

Understanding the changes in diverse molecular pathways underlying the development of breast tumors is critical for improving diagnosis, treatment, and drug development. Here, we used RNA-profiling of canine mammary tumors (CMTs) coupled with a robust analysis framework to model molecular changes in human breast cancer. Our study leveraged a key advantage of the canine model, the frequent presence of multiple naturally occurring tumors at diagnosis, thus providing samples spanning normal tissue and benign and malignant tumors from each patient. We showed human breast cancer signals, at both expression and mutation level, are evident in CMTs. Profiling multiple tumors per patient enabled by the CMT model allowed us to resolve statistically robust transcription patterns and biological pathways specific to malignant tumors versus those arising in benign tumors or shared with normal tissues. We showed that multiple histological samples per patient is necessary to effectively capture these progression-related signatures, and that carcinoma-specific signatures are predictive of survival for human breast cancer patients. To catalyze and support similar analyses and use of the CMT model by other biomedical researchers, we provide FREYA, a robust data processing pipeline and statistical analyses framework.

MicroRNA-3613-3p functions as a tumor suppressor and represents a novel therapeutic target in breast cancer

BACKGROUND

MicroRNAs have been reported to participate in tumorigenesis, treatment resistance, and tumor metastasis. Novel microRNAs need to be identified and investigated to guide the clinical prognosis or therapy for breast cancer.

METHOD

The copy number variations (CNVs) of MIR3613 from Cancer Genome Atlas (TCGA) or Cancer Cell Line Encyclopedia (CCLE) were analyzed, and its correlation with breast cancer subtypes or prognosis was investigated. The expression level of miR-3613-3p in tumor tissues or serum of breast cancer patients was detected using in situ hybridization and qPCR. Gain-of-function studies were performed to determine the regulatory role of miR-3613-3p on proliferation, apoptosis, and tumor sphere formation of human breast cancer cells MDA-MB-231 or MCF-7. The effects of miR-3613-3p on tumor growth or metastasis in an immunocompromised mouse model of MDA-MB-231-luciferase were explored by intratumor injection of miR-3613-3p analogue. The target genes, interactive lncRNAs, and related signaling pathways of miR-3613-3p were identified by bioinformatic prediction and 3'-UTR assays.

RESULTS

We found that MIR3613 was frequently deleted in breast cancer genome and its deletion was correlated with the molecular typing, and an unfavorable prognosis in estrogen receptor-positive patients. MiR-3613-3p level was also dramatically lower in tumor tissues or serum of breast cancer patients. Gain-of-function studies revealed that miR-3613-3p could suppress proliferation and sphere formation and promote apoptosis in vitro and impeded tumor growth and metastasis in vivo. Additionally, miR-3613-3p might regulate cell cycle by targeting SMS, PAFAH1B2, or PDK3 to restrain tumor progression.

CONCLUSION

Our findings indicate a suppressive role of miR-3613-3p in breast cancer progression, which may provide an innovative marker or treatment for breast cancer patients.

miR-301b-3p Regulates Breast Cancer Cell Proliferation, Migration, and Invasion by Targeting NR3C2

Objectives

Breast cancer is the most common malignant tumor among females, and miRNAs have been reported to play an important regulatory role in breast cancer progression. This study aimed to explore the function and underlying molecular mechanism of miR-301b-3p in breast cancer.

Methods

Differential analysis and survival analysis were performed based on the data accessed from the TCGA-BRCA dataset for identification of the target miRNA. Bioinformatics analysis was conducted to predict the downstream target gene of the miRNA. Real-time quantitative PCR was carried out to detect the expression of miR-301b-3p and nuclear receptor subfamily 3 group C member 2 (NR3C2). Western blot was used to assess the protein expression of NR3C2. Cell counting kit-8 assay was performed to evaluate the proliferation of breast cancer cells. Transwell assay was conducted to determine the migratory and invasive abilities of breast cancer cells. Dual-luciferase reporter assay was employed to verify the targeting relationship between miR-301b-3p and NR3C2.

Results

miR-301b-3p was elevated in breast cancer cell lines and promoted cell proliferation, migration, and invasion in terms of its biological function in breast cancer. NR3C2 was validated as a direct target of miR-301b-3p via bioinformatics analysis and dual-luciferase reporter assay, and NR3C2 was downregulated in breast cancer cell lines. The rescue experiment indicated that NR3C2 was involved in the mechanism by which miR-301b-3p regulated the malignant phenotype of breast cancer cells.

Conclusion

The present study revealed for the first time that miR-301b-3p could foster breast cancer cell proliferation, migration, and invasion by targeting NR3C2, unveiling that miR-301b-3p is a novel carcinogen in breast cancer.

The emerging CDK4/6 inhibitor for breast cancer treatment

The cyclin-dependent kinase (CDK) inhibitors have emerged as important cancer therapeutics. To date, three CDK4/6 inhibitors in combination with endocrine therapy have been approved by the U.S. Food and Drug Administration for the treatment of hormone receptor-positive, HER2-negative advanced breast cancer. These include, palbociclib, ribociclib and abemaciclib. More recently, a newer CDK4/6 inhibitor named dalpiciclib has been tested in the phase III DAWNA-1 study, which is a randomized, double-blind, placebo-controlled trial that investigates dalpiciclib in combination with fulvestrant in hormone receptor-positive, HER2-negative advanced breast cancer patients that have relapsed or progressed on prior endocrine therapy. Dalpiciclib is an oral agent and an emerging ATP-competitive CDK4/6 inhibitor. The interim results of DAWNA-1 study revealed that dalpiciclib in combination with fulvestrant significantly prolonged the progression-free survival. The clinical use and side effects of palbociclib, ribociclib and abemaciclib as well as dalpiciclib are reviewed here.

[Influence of the HLDF differentiation factor on the production of cytokines by bio-tissues of breast tissue in its non-malignant diseases and in invasive carcinoma of a non-specific type]

We studied the effect of the HLDF differentiation factor on production of cytokines by biopsy samples of nonmalignant breast diseases (ND) and invasive breast carcinoma of no special type (IBC-NST), in the absence and presence of lymphogenic metastasis: IBC-NST patients werw subdivided into groups on the prognostic protocol of the 8th edition of the AJCC committee. Group IA consisted of patients with T1-T2 tumor sizes, and predominantly with positive expression of estrogen and progesterone receptors (ER+/PR+/HER2-); it also included one patient with the HER2+ (ER-/PR-/HER2+) molecular subtype. The IB group was mainly composed of patients with T2 tumor size, with the presence of lymphogenic metastasis (in 8 out of 10) patients and with positive expression of estrogen and progesterone receptors (ER+/PR+/HER2-) and it also included three patients with the HER2+ (ER-/PR-/HER2+) molecular subtype. Group IIA consisted of patients with T1-T2 tumor sizes, mainly with no metastases in the lymph nodes (in 11 out of 12 patients) and with a triple negative molecular subtype. Group IIB included patients with T2 tumor size, the presence of nodal metastasis and the expression of markers of ER-/PR-/HER2 - and ER-/PR-/HER2+. Group IIIA consisted of patients with tumor size T1-T3, with the presence of nodal metastasis and the expression of markers of ER-/PR+/HER2+ and ER-/PR-/HER2+. Group IIIC consisted of patients with T3 tumor size, lymphogenic metastasis, and expression of ER-/PR-/HER2-markers (triple negative molecular subtype). Due to a limited number of patients in the groups IIB, IIIA and IIIC, as well as due to more severe clinical and pathological stages, according to the prognostic Protocol of the 8th edition of the AJCC Committee, they were pooled into group III. Concentrations of IL-2, IL-4, IL-6, IL-8, IL-10, IL-17, IL-18, IL-1β, IL-1Ra, TNF-α, IFN-γ, G-CSF, GM-CSF, VEGF and MCP-1 were assayed in supernatants of biopsy specimens of breast tissue. Results have shown that with IBC-NST, a statistically significantly higher level of spontaneous production (SP) by biopsy specimens of IL-17, IL-18, IFN-γ and VEGF, and a lower level of SP IL-6 as compared with ND. Patients of all clinical and pathological groups showed a high VEGF spontaneous production as compared with ND, while statistically significant differences from patients with ND were not found in IL-17 spontaneous production in group IB patients, and IL-18 spontaneous production were absent in group IA. Only in patients with IA and IB, the IL-6 spontaneous production was lower as compared to ND, and the IL-8 spontaneous production was lower in the IA group. IFN-γ spontaneous production was higher in patients with IBC-NST group IIA as compared with ND. Under the influence of the HLDF differentiation factor, it was found that the parameters of IBC-NST patients were statistically significantly higher in the production of IL-1Ra, IL-17, IL-18 and VEGF, and statistically significantly lower in the production of IL-6 as compared to ND. HLDF had a higher impact on the content of IL-18 in IBC-NST patients than in ND. After HDLF sublimation IL-6 values were lower in patients of groups IA and IB, and HLDF-induced IL-17 production was higher only in patients of group IA. Statistically significant differences in the index of influence of HLDF (IVHLDF), representing ratio of the cytokine concentration in the supernatants of a biopsy specimen stimulated by HLDF to spontaneous cytokine production, were found between ND and IBC-NST in the case of on IFN-γ production, and also in the case of IL-4 production (between patients in the absence and presence of lymphogenic metastasis). IVHLDF for production of IL-6, IL-8 and TNF-α was lower in group IIA patients compared to group IA, and IVHLDF for production of GM-CSF and MCP-1 was lower in group IIA as compared to group III, in addition IVHLDF for MCP-1 products was lower in group IIA as compared to ND. The HLDF effect on the cytokine production by the tumor and its microenvironment was different in ND patients and IBC-NST patients. HDLF suppressed IFN-γ production in the pooled group of IBC-NST patients; HLDF mainly had a suppressive effect on the production of IL-6, IL-8, TNF-α, GM-CSF and MCP-1 in IBC-NST patients of group IIA.

Coexpress of GATA-3 and ER in Anorectal and Head and Neck Squamous Cell Carcinoma Mimicking Metastatic Breast Cancer

GATA binding protein 3 (GATA-3) is a sensitive marker for breast and urothelial carcinomas. In combination with the estrogen receptor (ER), it is often used for differential diagnosis of metastatic carcinomas of breast origin. In this study, we sought to characterize GATA-3 and ER expression in squamous cell carcinoma (SqCC) of various origins to compare with breast carcinoma. Sixty-four SqCC of anorectum (35), head and neck (15), lung (11), and breast (3) as well as urothelial carcinoma (31) were included. In anorectal and head and neck SqCC, GATA-3, and ER was observed in 23/50 (46.0%) and 18/50 (36.0%) of the cases, respectively. The expression of GATA-3 and ER were present in both male and female patients without significant sex predominance. In 2 metastatic SqCC, the GATA-3 and ER expressed similar immunoreactivity compatible with their anorectal primary. Progesterone receptor was only expressed in 2 anorectal SqCC and none of head and neck SqCC or urothelial carcinomas. None of the lung SqCC expressed GATA-3 or ER (0/11). p16 was expressed in the majority of head and neck (6/12) and anorectal SqCC (26/27). Our study demonstrated that the combination of GATA-3 and ER positivity is not entirely specific for breast carcinomas, since both stains are expressed in SqCC from anorectal and head and neck origins. Clinical workup for metastatic carcinoma of suspicious breast origin should be cognizant of other tumors with a similar immunohistochemical profile (ie, SqCC).

Immune Escape during Breast Tumor Progression

Immunotherapy using checkpoint inhibitors is one of the most promising current cancer treatment strategies. However, in breast cancer, its success has been limited to a subset of patients with triple-negative disease, whose durability of observed responses remain unclear. The lack of detailed understanding of breast tumor immune evasion mechanisms and the treatment of patients with highly heterogeneous metastatic disease contribute to these disappointing results. Here we discuss the current knowledge about immune-related changes during breast tumor progression, with special emphasis on the in situ-to-invasive breast carcinoma transition that may represent a key step of immunoediting in breast cancer. Comprehensive characterization of early-stage disease and better understanding of immunologic drivers of disease progression will likely expand the tools available for immunotherapy and improve patient stratification.

Do Histopathology and Clinical Outcomes of Breast Atypia Vary by Race/Ethnicity?

BACKGROUND

The clinical behavior of breast cancer varies by racial and ethnic makeup (REM), but the impact of REM on the clinical outcomes of breast atypia remains understudied. We examined the impact of REM on risk of underlying or subsequent carcinoma following a diagnosis of breast atypia.

METHODS

In this retrospective, single-institution chart review, adult women diagnosed with breast atypia (atypical ductal hyperplasia, atypical lobular hyperplasia, or lobular carcinoma in situ) were stratified by REM. Regression modeling was used to estimate risk of underlying or subsequent carcinoma.

RESULTS

We identified 539 patients with breast atypia, including 15 Hispanic (2.8%), 127 non-Hispanic black (23.6%), and 397 non-Hispanic white women (73.7%). Diagnoses included 75.1% atypical ductal hyperplasia (n = 405), 4.6% atypical lobular hyperplasia (n = 25), and 20.2% lobular carcinoma in situ (n = 109). Rates for each type of atypia did not vary by REM (P = 0.33). Of those with atypia on needle biopsy, the rate of underlying carcinoma at excision was 17.3%. After adjustment, REM was not associated with greater risk for carcinoma at excision (P = 0.41). Of those with atypia alone on surgical excision, the rate of a subsequent carcinoma diagnosis was 15.4% (median follow-up 49 mo). REM was not associated with a long-term risk for carcinoma (P = 0.37) or differences in time to subsequent carcinoma (log-rank P = 0.52). Chemoprevention uptake rates were low (10.6%), especially among Hispanic (0%) and non-Hispanic black (3.8%) patients (P = 0.01).

CONCLUSIONS

Among patients with atypia, REM does not appear to influence type of histologic atypia, risk for carcinoma, or clinical outcome, despite differences in chemoprevention rates.

Epigenome-wide DNA methylation and risk of breast cancer: a systematic review

BACKGROUND

DNA methylation is a potential biomarker for early detection of breast cancer. However, robust evidence of a prospective relationship between DNA methylation patterns and breast cancer risk is still lacking. The objective of this study is to provide a systematic analysis of the findings of epigenome-wide DNA methylation studies on breast cancer risk, in light of their methodological strengths and weaknesses.

METHODS

We searched major databases (MEDLINE, EMBASE, Web of Science, CENTRAL) from inception up to 30th June 2019, for observational or intervention studies investigating the association between epigenome-wide DNA methylation (using the HM450k or EPIC BeadChip), measured in any type of human sample, and breast cancer risk. A pre-established protocol was drawn up following the Cochrane Reviews rigorous methodology. Study selection, data abstraction, and risk of bias assessment were performed by at least two investigators. A qualitative synthesis and systematic comparison of the strengths and weaknesses of studies was performed.

RESULTS

Overall, 20 studies using the HM450k BeadChip were included, 17 of which had measured blood-derived DNA methylation. There was a consistent trend toward an association of global blood-derived DNA hypomethylation and higher epigenetic age with higher risk of breast cancer. The strength of associations was modest for global hypomethylation and relatively weak for most of epigenetic age algorithms. Differences in length of follow-up periods may have influenced the ability to detect associations, as studies reporting follow-up periods shorter than 10 years were more likely to observe an association with global DNA methylation. Probe-wise differential methylation analyses identified between one and 806 differentially methylated CpGs positions in 10 studies. None of the identified differentially methylated sites overlapped between studies. Three studies used breast tissue DNA and suffered major methodological issues that precludes any conclusion. Overall risk of bias was critical mainly because of incomplete control of confounding. Important issues relative to data preprocessing could have limited the consistency of results.

CONCLUSIONS

Global DNA methylation may be a short-term predictor of breast cancer risk. Further studies with rigorous methodology are needed to determine spatial distribution of DNA hypomethylation and identify differentially methylated sites associated with risk of breast cancer.

PROSPERO REGISTRATION NUMBER

CRD42020147244.

TRPC6 channel and its implications in breast cancer: an overview

TRPC6 channel is widely expressed in most human tissues and participates in a number of physiological processes. TRPC6 belongs to the DAG-activated subfamily of channels, but has also been postulated as a mediator in the store-operated calcium entry pathway. The recent characterization of TRPC6 crystal structure has granted a wonderful tool to finally dissect and understand TRPC6 physiological and biophysical properties. Growing evidences have demonstrated that the pattern of expression of TRPC6 proteins is upregulated in several pathophysiological conditions, including breast cancer. However, the real role of TRPC6 in breast cancer persists still unknown. Here we present the current state of the art concerning the function and significance of TRPC6 in this disease. Future investigations should be focus in the creation and identification of compounds that specifically target the channel to ameliorate TRPC6-related diseases.

Long Non-Coding Small Nucleolar RNA Host Genes (SNHGs) in Endocrine-Related Cancers

Long non-coding RNAs (lncRNAs) are emerging regulators of a diverse range of biological processes through various mechanisms. Genome-wide association studies of tumor samples have identified several lncRNAs, which act as either oncogenes or tumor suppressors in various types of cancers. Small nucleolar RNAs (snoRNAs) are predominantly found in the nucleolus and function as guide RNAs for the processing of transcription. As the host genes of snoRNAs, lncRNA small nucleolar RNA host genes (SNHGs) have been shown to be abnormally expressed in multiple cancers and can participate in cell proliferation, tumor progression, metastasis, and chemoresistance. Here, we review the biological functions and emerging mechanisms of SNHGs involved in the development and progression of endocrine-related cancers including thyroid cancer, breast cancer, pancreatic cancer, ovarian cancer and prostate cancer.

Systematic analysis of breast atypical hyperplasia-associated hub genes and pathways based on text mining

The purpose of this study was to describe breast atypical hyperplasia (BAH)-related gene expression and to systematically analyze the functions, pathways, and networks of BAH-related hub genes. On the basis of natural language processing, gene data for BAH were extracted from the PubMed database using text mining. The enriched Gene Ontology terms and Kyoto Encyclopedia of Genes and Genomes pathways were obtained using DAVID (http://david.abcc.ncifcrf.gov/). A protein–protein interaction network was constructed using the STRING database. Hub genes were identified as genes that interact with at least 10 other genes within the BAH-related gene network. In total, 138 BAH-associated genes were identified as significant (P < 0.05), and 133 pathways were identified as significant (P < 0.05, false discovery rate < 0.05). A BAH-related protein network that included 81 interactions was constructed. Twenty genes were determined to interact with at least 10 others (P < 0.05, false discovery rate < 0.05) and were identified as the BAH-related hub genes of this protein–protein interaction network. These 20 genes are TP53, PIK3CA, JUN, MYC, EGFR, CCND1, AKT1, ERBB2, CTNN1B, ESR1, IGF-1, VEGFA, HRAS, CDKN1B, CDKN1A, PCNA, HGF, HIF1A, RB1, and STAT5A. This study may help to disclose the molecular mechanisms of BAH development and provide implications for BAH-targeted therapy or even breast cancer prevention. Nevertheless, connections between certain genes and BAH require further exploration.

Electrochemical Nanobiosensors for Detection of Breast Cancer Biomarkers

This comprehensive review paper describes recent advances made in the field of electrochemical nanobiosensors for the detection of breast cancer (BC) biomarkers such as specific genes, microRNA, proteins, circulating tumor cells, BC cell lines, and exosomes or exosome-derived biomarkers. Besides the description of key functional characteristics of electrochemical nanobiosensors, the reader can find basic statistic information about BC incidence and mortality, breast pathology, and current clinically used BC biomarkers. The final part of the review is focused on challenges that need to be addressed in order to apply electrochemical nanobiosensors in a clinical practice.

Genomic profiling of pleomorphic and florid lobular carcinoma in situ reveals highly recurrent ERBB2 and ERRB3 alterations

Pleomorphic LCIS (P-LCIS) and florid LCIS (F-LCIS) are morphologic variants distinguished from classic LCIS by marked nuclear pleomorphism and/or an expansile growth pattern with or without necrosis. Given the rarity of these LCIS variants, little data exist regarding their molecular pathogenesis, natural history, and optimal management. The purpose of this study was to genomically profile LCIS variants to gain further insight into their biology. Nineteen cases of pure LCIS variants (17 P-LCIS, 2 F-LCIS) diagnosed on core needle biopsy at our institution from 2006 to 2017 were included, five of which were upgraded to invasive cancer at excision. Macrodissected lesions were analyzed by a hybrid-capture next generation sequencing assay that surveyed exonic sequences of 447 genes for mutations and copy number variations (CNVs) and 191 regions across 60 genes for structural rearrangements. LCIS variants were all confirmed as E-cadherin negative by immunohistochemistry. Receptor profiles among the 17 P-LCIS cases included HR+/HER2- (nine cases), HR+/HER2+ (three cases), HR-/HER2+ (two cases), and HR-/HER2- (three cases). The two F-LCIS cases were HR+/HER2- and HR+/HER2+. All LCIS variants had genetic alterations consistent with a lobular phenotype including 1q gain (16 cases), 16q loss (18 cases), and CDH1 mutations (18 cases). Highly recurrent ERBB2 alterations were noted including mutations (13 cases) and amplifications (six cases). Other significant alterations included mutations in PIK3CA (six cases), RUNX1 (four cases), ERBB3 (four cases), and CBFB (three cases), as well as amplification of CCND1 (five cases). A TP53 mutation was identified in one case of HR-/HER2+ P-LCIS with signet ring cell features that lacked 1q gain and 16q loss. P-LCIS and F-LCIS contain genetic alterations characteristic of lobular neoplasia; however, these LCIS variants are distinguished from classical LCIS reported in the literature by their highly recurrent ERBB2 alterations.

Loss of myoepithelial calponin-1 characterizes high-risk ductal carcinoma in situ cases, which are further stratified by T cell composition

A hallmark of ductal carcinoma in situ (DCIS) progression is a loss of the surrounding ductal myoepithelium. However, whether compromise in myoepithelial differentiation, rather than overt cellular loss, can be used to predict the risk of DCIS progression is unknown. Here we address this question utilizing pure and mixed DCIS cases (N = 30) as surrogates for DCIS at low and high risk for progression, respectively. We used multiplex immunohistochemical staining to evaluate the relationship between myoepithelial cell differentiation and lymphoid immune cell types associated with poor prognostic DCIS. Our results show that myoepithelial calponin-1 discriminates between pure and mixed DCIS lesions better than histological subtype, presence of necrosis, or nuclear grade. Additionally, focal loss of myoepithelial cells associated with increased PD-1+CD8+ T cells, which suggests a link between the myoepithelium and immune surveillance. To identify associations between calponin-1 expression and immune response, we performed unsupervised hierarchical clustering of myoepithelial and immune cell biomarkers on 219 DCIS lesions from 30 cases. Notably, the majority of pure (low-risk) DCIS lesions clustered in a high calponin-1, T cell low group, whereas the majority of mixed (high-risk) DCIS lesions clustered in a low calponin-1, T cell high group, specifically with CD8+ and PD-1+CD8+ T cells. However, a subset of pure DCIS lesions had a similar calponin-1 and immune signature as the majority of mixed DCIS lesions, which have low calponin-1 and T cell enrichment-raising the possibility that these pure DCIS lesions might be at a high risk for progression.

Morphologic and Genomic Heterogeneity in the Evolution and Progression of Breast Cancer

: Breast cancer is a remarkably complex and diverse disease. Subtyping based on morphology, genomics, biomarkers and/or clinical parameters seeks to stratify optimal approaches for management, but it is clear that every breast cancer is fundamentally unique. Intra-tumour heterogeneity adds further complexity and impacts a patient's response to neoadjuvant or adjuvant therapy. Here, we review some established and more recent evidence related to the complex nature of breast cancer evolution. We describe morphologic and genomic diversity as it arises spontaneously during the early stages of tumour evolution, and also in the context of treatment where the changing subclonal architecture of a tumour is driven by the inherent adaptability of tumour cells to evolve and resist the selective pressures of therapy.

Breast cancer

Breast cancer is the most frequent malignancy in women worldwide and is curable in ~70-80% of patients with early-stage, non-metastatic disease. Advanced breast cancer with distant organ metastases is considered incurable with currently available therapies. On the molecular level, breast cancer is a heterogeneous disease; molecular features include activation of human epidermal growth factor receptor 2 (HER2, encoded by ERBB2), activation of hormone receptors (oestrogen receptor and progesterone receptor) and/or BRCA mutations. Treatment strategies differ according to molecular subtype. Management of breast cancer is multidisciplinary; it includes locoregional (surgery and radiation therapy) and systemic therapy approaches. Systemic therapies include endocrine therapy for hormone receptor-positive disease, chemotherapy, anti-HER2 therapy for HER2-positive disease, bone stabilizing agents, poly(ADP-ribose) polymerase inhibitors for BRCA mutation carriers and, quite recently, immunotherapy. Future therapeutic concepts in breast cancer aim at individualization of therapy as well as at treatment de-escalation and escalation based on tumour biology and early therapy response. Next to further treatment innovations, equal worldwide access to therapeutic advances remains the global challenge in breast cancer care for the future.

The Influence of Age on the Histopathology and Prognosis of Atypical Breast Lesions

BACKGROUND

Although several prognostic variables and risk factors for breast cancer are age-related, the association between age and risk of cancer with breast atypia is controversial. This study aimed to compare the type of breast atypia and risk of underlying or subsequent breast cancer by age.

METHODS

Adult women with breast atypia (atypical ductal hyperplasia, atypical lobular hyperplasia, and lobular carcinoma in situ) at a single institution from 2008 to 2017 were stratified by age at initial diagnosis: <50 y, 50-70 y, and >70 y. Regression modeling was used to estimate the association of age with risk of underlying carcinoma or subsequent cancer diagnosis.

RESULTS

A total of 530 patients with atypia were identified: 31.1% < 50 y (n = 165), 58.1% 50-70 y (n = 308), and 10.8% > 70 y (n = 57). The proportion of women with atypical ductal hyperplasia steadily increased with age, compared with atypical lobular proliferations (P = 0.04). Of those with atypia on needle biopsy, the overall rate of underlying carcinoma was 17.5%. After adjustment, older age was associated with a greater risk of underlying carcinoma (odds ratio: 1.028, 95% confidence interval: 1.003-1.053; P = 0.03). Of those confirmed to have atypia on surgical excision, the overall rate of a subsequent cancer diagnosis was 15.7%. Age was not associated with a long-term risk for breast cancer (P = 0.48) or the time to a subsequent diagnosis of carcinoma (log-rank P = 0.41).

CONCLUSIONS

Although atypia diagnosed on needle biopsy may be sufficient to warrant surgical excision, older women may be at a greater risk for an underlying carcinoma, albeit the long-term risk for malignancy associated with atypia does not appear to be affected by age.

Heterogeneous risk profiles among B3 breast lesions of uncertain malignant potential

Background:

Most cases of breast lesions of uncertain malignant potential (B3) undergo surgical intervention. We aimed to analyze the outcome of B3 lesion subtypes in a large series of screen-detected cases.

Methods:

We screened 2,986 core needle biopsies to classify B3 lesions. Positive predictive values (PPVs) for malignancy were calculated for a comprehensive risk characterization according to clinicopathologic and morphologic variables.

Results:

B3 lesions comprised 35% atypical ductal hyperplasia (PPV = 20%), 16.7% flat epithelial atypia (PPV = 12%), 22.7% lobular neoplasia (PPV = 16.2%), 9% papillary lesion (PPV = 18.5%), 8.6% phyllodes tumor (PPV = 3.8%), and 8% radial scars (PPV = 4.1%) based on histopathologic diagnosis. Upgrade rates were 15.9% for calcifications, 13.7% for mass lesions, and 16.7% for architectural deformities, with 8.3% of malignant lesions classified as ductal carcinoma in situ and 6.7% as invasive cancers (PPV = 15%).

Conclusion:

B3 lesions entail a heterogeneous risk of malignancy, and careful radiologic–pathologic correlation is required for optimal treatment.

Ductal Carcinoma in Situ: Current Concepts in Biology, Imaging, and Treatment

Ductal carcinoma in situ (DCIS) of the breast is a group of heterogeneous epithelial proliferations confined to the milk ducts that nearly always present in asymptomatic women on breast cancer screening. A stage 0, preinvasive breast cancer, increased detection of DCIS was initially hailed as a means to prevent invasive breast cancer through surgical treatment with adjuvant radiation and/or endocrine therapies. However, controversy in the medical community has emerged in the past two decades that a fraction of DCIS represents overdiagnosis, leading to unnecessary treatments and resulting morbidity. The imaging hallmarks of DCIS include linearly or segmentally distributed calcifications on mammography or nonmass enhancement on breast MRI. Imaging features have been shown to reflect the biological heterogeneity of DCIS lesions, with recent studies indicating MRI may identify a greater fraction of higher-grade lesions than mammography does. There is strong interest in the surgical, imaging, and oncology communities to better align DCIS management with biology, which has resulted in trials of active surveillance and therapy that is less aggressive. However, risk stratification of DCIS remains imperfect, which has limited the development of precision therapy approaches matched to DCIS aggressiveness. Accordingly, there are opportunities for breast imaging radiologists to assist the oncology community by leveraging advanced imaging techniques to identify appropriate patients for the less aggressive DCIS treatments.

Gene expression signature of atypical breast hyperplasia and regulation by SFRP1

Background

Atypical breast hyperplasias (AH) have a 10-year risk of progression to invasive cancer estimated at 4–7%, with the overall risk of developing breast cancer increased by ~ 4-fold. AH lesions are estrogen receptor alpha positive (ERα+) and represent risk indicators and/or precursor lesions to low grade ERα+ tumors. Therefore, molecular profiles of AH lesions offer insights into the earliest changes in the breast epithelium, rendering it susceptible to oncogenic transformation.

Methods

In this study, women were selected who were diagnosed with ductal or lobular AH, but no breast cancer prior to or within the 2-year follow-up. Paired AH and histologically normal benign (HNB) tissues from patients were microdissected. RNA was isolated, amplified linearly, labeled, and hybridized to whole transcriptome microarrays to determine gene expression profiles. Genes that were differentially expressed between AH and HNB were identified using a paired analysis. Gene expression signatures distinguishing AH and HNB were defined using AGNES and PAM methods. Regulation of gene networks was investigated using breast epithelial cell lines, explant cultures of normal breast tissue and mouse tissues.

Results

A 99-gene signature discriminated the histologically normal and AH tissues in 81% of the cases. Network analysis identified coordinated alterations in signaling through ERα, epidermal growth factor receptors, and androgen receptor which were associated with the development of both lobular and ductal AH. Decreased expression of SFRP1 was also consistently lower in AH. Knockdown of SFRP1 in 76N-Tert cells resulted altered expression of 13 genes similarly to that observed in AH. An SFRP1-regulated network was also observed in tissues from mice lacking Sfrp1. Re-expression of SFRP1 in MCF7 cells provided further support for the SFRP1-regulated network. Treatment of breast explant cultures with rSFRP1 dampened estrogen-induced progesterone receptor levels.

Conclusions

The alterations in gene expression were observed in both ductal and lobular AH suggesting shared underlying mechanisms predisposing to AH. Loss of SFRP1 expression is a significant regulator of AH transcriptional profiles driving previously unidentified changes affecting responses to estrogen and possibly other pathways. The gene signature and pathways provide insights into alterations contributing to AH breast lesions.

Electronic supplementary material

The online version of this article (10.1186/s13058-019-1157-5) contains supplementary material, which is available to authorized users.

Downregulation of miR-505 promotes cell proliferation, migration and invasion, and predicts poor prognosis in breast cancer

microRNAs are involved in the tumor progression of various cancer types. The present study aimed to determine the prognostic significance of microRNA-505 (miR-505) in patients with breast cancer and investigate the functional role of miR-505 in BCa progression. The expression of miR-505 was estimated using reverse transcription-quantitative polymerase chain reaction. Kaplan-Meier survival curves and Cox regression analysis were used to evaluate the prognostic value of miR-505 in patients with BCa. Cell experiments were performed to assess the biological function of miR-505 during BCa progression. A significant downregulated expression level of miR-505 was observed in BCa tissues and cells compared with the corresponding controls (P<0.001). The expression of miR-505 was significantly associated with distant metastasis status (P=0.013) and Tumor-Node-Metastasis staging (P=0.002). Furthermore, the overall survival time was significantly shorter for patients with low miR-505 expression compared with those with high miR-505 expression (P<0.001). In addition, miR-505 was identified as an independent prognostic factor for BCa. The results of cell experiments revealed that an overexpression of miR-505 could significantly inhibit BCa cell proliferation, migration and invasion, whereas a downregulation of miR-505 significantly enhanced BCa cell proliferation, migration and invasion (P<0.05). In summary, all data indicated that a low miR-505 expression level is associated with a poor prognosis for patients with BCa and promotes tumor cell proliferation, migration and invasion. Therefore, the aberrant expression of miR-505 may serve as a therapeutic target for BCa.

Atypical ductal hyperplasia is a multipotent precursor of breast carcinoma

The current model for breast cancer progression proposes independent 'low grade (LG)-like' and 'high grade (HG)-like' pathways but lacks a known precursor to HG cancer. We applied low-coverage whole-genome sequencing to atypical ductal hyperplasia (ADH) with and without carcinoma to shed light on breast cancer progression. Fourteen out of twenty isolated ADH cases harboured at least one copy number alteration (CNA), but had fewer aberrations than LG or HG ductal carcinoma in situ (DCIS). ADH carried more HG-like CNA than LG DCIS (e.g. 8q gain). Correspondingly, 64% (7/11) of ADH cases with synchronous HG carcinoma were clonally related, similar to LG carcinoma (67%, 6/9). This study represents a significant shift in our understanding of breast cancer progression, with ADH as a common precursor lesion to the independent 'low grade-like' and 'high grade-like' pathways. These data suggest that ADH can be a precursor of HG breast cancer and that LG and HG carcinomas can evolve from a similar ancestor lesion. We propose that although LG DCIS may be committed to a LG molecular pathway, ADH may remain multipotent, progressing to either LG or HG carcinoma. This multipotent nature suggests that some ADH cases could be more clinically significant than LG DCIS, requiring biomarkers for personalising management. Copyright © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

TBX3 promotes progression of pre-invasive breast cancer cells by inducing EMT and directly up-regulating SLUG

The acquisition of cellular invasiveness by breast epithelial cells and subsequent transition from ductal carcinoma in situ (DCIS) to invasive breast cancer is a critical step in breast cancer progression. Little is known about the molecular dynamics governing this transition. We have previously shown that overexpression of the transcriptional regulator TBX3 in DCIS‐like cells increases survival, growth, and invasiveness. To explore this mechanism further and assess direct transcriptional targets of TBX3 in a high‐resolution, isoform‐specific context, we conducted genome‐wide chromatin‐immunoprecipitation (ChIP) arrays coupled with transcriptomic analysis. We show that TBX3 regulates several epithelial–mesenchymal transition (EMT)‐related genes, including SLUG and TWIST1. Importantly, we demonstrate that TBX3 is a direct regulator of SLUG expression, and SLUG expression is required for TBX3‐induced migration and invasion. Assessing TBX3 by immunohistochemistry in early‐stage (stage 0 and stage I) breast cancers revealed high expression in low‐grade lesions. Within a second independent early‐stage non‐high‐grade cohort, we observed an association between TBX3 level in the DCIS and size of the invasive focus. Additionally, there was a positive correlation between TBX3 and SLUG, and TBX3 and TWIST1 in the invasive carcinoma. Pathway analysis revealed altered expression of several proteases and their inhibitors, consistent with the ability to degrade basement membrane in vivo. These findings strongly suggest the involvement of TBX3 in the promotion of invasiveness and progression of early‐stage pre‐invasive breast cancer to invasive carcinoma through the low‐grade molecular pathway. © 2019 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Quantitative and Specific Detection of Exosomal miRNAs for Accurate Diagnosis of Breast Cancer Using a Surface-Enhanced Raman Scattering Sensor Based on Plasmonic Head-Flocked Gold Nanopillars

MicroRNAs in exosomes (exosomal miRNAs) have attracted increased attention as cancer biomarkers for early diagnosis and prognosis owing to their stability in body fluids. Since strong association exists between exosomal miRNA expression levels and breast cancer, the development of effective methods that can monitor exosomal miRNA expression both over broad concentration ranges and in ultralow amounts is critical. Here, a surface-enhanced Raman scattering (SERS)-based sensing platform is developed for the quantitative determination of exosomal miRNAs. Ultrasensitive exosomal miRNA detection with single-nucleotide specificity is obtained from enhanced SERS signals from a uniform plasmonic head-flocked gold nanopillar substrate, which generates multiple hotspots and enables hybridization between short oligonucleotides, i.e., miRNAs and locked nucleic acid probes. The proposed SERS sensor shows an extremely low detection limit without any amplification process, a wide dynamic range (1 am to 100 nm), multiplex sensing capability and sound miRNA recovery in serum. Furthermore, this sensor allows reliable observation of exosomal miRNA expression patterns from breast cancer cell lines and can discriminate breast cancer subtype based on the difference between these patterns. The results suggest that this sensor can be used for universal cancer diagnosis and further biomedical applications through the quantitative measurement of exosomal miRNAs in bodily fluids.

The next generation personalized models to screen hidden layers of breast cancer tumorigenicity

BACKGROUND

Breast cancer (BC) is a challenging disease and major cause of death amongst women worldwide who die due to tumor relapse or sidelong diseases. BC main complexity comes from the heterogeneous nature of breast tumors that demands customized treatments in the form of personalized medicine.

REVIEW OF THE LITERATURE AND DISCUSSION

Spatiotemporally dynamic and heterogeneous nature of BC tumors is shaped by their clonal evolution and sub-clonal selections and shapes resistance to collective or group therapies that drives cancer recurrence and tumor metastasis. Personalized intervention promises to administer medications that selectively target each individual patient tumor and even further each colonized secondary tumor. Such personalized regimens will require creation of in vitro and in vivo models genuinely recapitulating characteristics of each tumor type as initiating platforms for two main purposes: to closely monitor the tumorigenic processes that shape tumor heterogeneity and evolution as the main driving forces behind tumor chemo-resistance and relapse, and subsequently to establish patient-specific preventive and therapeutic measures. While application of tumor modeling for personalized drug screening and design requires a separate review, here we discuss the personalized utilities of xenograft modeling in investigating BC tumor formation and progression toward metastasis. We will further elaborate on the impact of innovative technologies on personalized modeling of BC tumorigenicity at improved resolution.

CONCLUSION

Heterogeneous nature of each BC tumor requires personalized intervention implying that modeling breast tumors is inevitable for better disease understanding, detection and cure. Patient-derived xenografts are just the initiating piece of the puzzle for ideal management of breast cancer. Emerging technologies promise to model BC more personalized than before.

MicroRNA-449b-5p suppresses the growth and invasion of breast cancer cells via inhibiting CREPT-mediated Wnt/β-catenin signaling

Accumulating evidence has suggested that microRNA-449b-5p (miR-449b-5p) plays an important role in the development and progression of multiple cancers. However, little is known about the role of miR-449b-5p in breast cancer. In this study, we aimed to investigate the expression level, biological function and underlying mechanism of miR-449b-5p in breast cancer. Our results showed that miR-449b-5p expression was frequently down-regulated in breast cancer cell lines and tissues. The overexpression of miR-449b-5p significantly inhibited growth and invasion, and induced the cell cycle arrest of breast cancer cells. In contrast, the inhibition of miR-449b-5p showed the opposite effect. Interestingly, bioinformatic analysis predicted that cell cycle-related and expression-elevated protein in tumor (CREPT), an important oncogene in breast cancer, was a potential target gene of miR-449b-5p. The overexpression of miR-449b-5p decreased CREPT expression while miR-449b-5p inhibition promoted CREPT expression in breast cancer cells. Restoration of CREPT expression in miR-449b-5p mimics transfected cells partially reversed the suppressive effect of miR-449b-5p on breast cancer cell growth and invasion. Notably, our results showed that miR-449b-5p overexpression decreased the expression of β-catenin and suppressed the activation of Wnt/β-catenin/TCF-4 signaling via targeting CREPT. In addition, blocking Wnt/β-catenin partially reversed the promotion effect of miR-449b-5p inhibition on breast cancer cell growth and invasion. Overall, these results reveal a tumor suppressive role of miR-449b-5p that restricts the growth and invasion of breast cancer cells through targeting CREPT and inhibiting CREPT-mediated activation of Wnt/β-catenin signaling. Our study suggests that the miR-449b-5p/CREPT/Wnt/β-catenin axis may play an important role in the pathogenesis of breast cancer and miR-449-5p may serve as a potential therapeutic target for breast cancer.