Inflammatory breast cancer cells are characterized by abrogated TGFβ1-dependent cell motility and SMAD3 activity

Deciphering the molecular biology of inflammatory breast cancer through molecular characterization of patient samples and preclinical models

Inflammatory breast cancer is an aggressive subtype of breast cancer with dismal patient prognosis and a unique clinical presentation. In the past two decades, molecular profiling technologies have been used in order to gain insight into the molecular biology of IBC and to search for possible targets for treatment. Although a gene signature that accurately discriminates between IBC and nIBC patient samples and preclinical models was identified, the overall genomic and transcriptomic differences are small and ambiguous, mainly due to the limited sample sizes of the evaluated patient series and the failure to correct for confounding effects of the molecular subtypes. Nevertheless, data collected over the past 20 years by independent research groups increasingly support the existence of several IBC-specific biological characteristics. In this review, these features are classified as established, emerging and conceptual hallmarks based on the level of evidence reported in the literature. In addition, a synoptic model is proposed that integrates all hallmarks and that can explain how cancer cell intrinsic mechanisms (i.e. NF-κB activation, genomic instability, MYC-addiction, TGF-β resistance, adaptive stress response, chromatin remodeling, epithelial-to-mesenchymal transition) can contribute to the establishment of the dynamic immune microenvironment associated with IBC. It stands to reason that future research projects are needed to further refine (parts of) this model and to investigate its clinical translatability.

MicroRNAs as the pivotal regulators of cisplatin resistance in osteosarcoma

Osteosarcoma (OS) is an aggressive bone tumor that originates from mesenchymal cells. It is considered as the eighth most frequent childhood cancer that mainly affects the tibia and femur among the teenagers and young adults. OS can be usually diagnosed by a combination of MRI and surgical biopsy. The intra-arterial cisplatin (CDDP) and Adriamycin is one of the methods of choices for the OS treatment. CDDP induces tumor cell death by disturbing the DNA replication. Although, CDDP has a critical role in improving the clinical complication in OS patients, a high ratio of CDDP resistance is observed among these patients. Prolonged CDDP administrations have also serious side effects in normal tissues and organs. Therefore, the molecular mechanisms of CDDP resistance should be clarified to define the novel therapeutic modalities in OS. Multidrug resistance (MDR) can be caused by various cellular and molecular processes such as drug efflux, detoxification, and signaling pathways. MicroRNAs (miRNAs) are the key regulators of CDDP response by the post transcriptional regulation of target genes involved in MDR. In the present review we have discussed all of the miRNAs associated with CDDP response in OS cells. It was observed that the majority of reported miRNAs increased CDDP sensitivity in OS cells through the regulation of signaling pathways, apoptosis, transporters, and autophagy. This review highlights the miRNAs as reliable non-invasive markers for the prediction of CDDP response in OS patients.

Signal Pathways and microRNAs in Osteosarcoma Growth and the Dual Role of Mesenchymal Stem Cells in Oncogenesis

The major challenges in Osteosarcoma (OS) therapy are its heterogeneity and drug resistance. The development of new therapeutic approaches to overcome the major growth mechanisms of OS is urgently needed. The search for specific molecular targets and promising innovative approaches in OS therapy, including drug delivery methods, is an urgent problem. Modern regenerative medicine focuses on harnessing the potential of mesenchymal stem cells (MSCs) because they have low immunogenicity. MSCs are important cells that have received considerable attention in cancer research. Currently, new cell-based methods for using MSCs in medicine are being actively investigated and tested, especially as carriers for chemotherapeutics, nanoparticles, and photosensitizers. However, despite the inexhaustible regenerative potential and known anticancer properties of MSCs, they may trigger the development and progression of bone tumors. A better understanding of the complex cellular and molecular mechanisms of OS pathogenesis is essential to identify novel molecular effectors involved in oncogenesis. The current review focuses on signaling pathways and miRNAs involved in the development of OS and describes the role of MSCs in oncogenesis and their potential for antitumor cell-based therapy.

Copy Number Variation in Inflammatory Breast Cancer

Identification of a unique genomic biomarker in de novo inflammatory breast cancer (IBC) may provide an insight into the biology of this aggressive disease. The goal of our study was to elucidate biomarkers associated with IBC. We examined breast biopsies collected from Dana–Farber Cancer Institute patients with IBC prior to initiating preoperative systemic treatment (30 samples were examined, of which 14 were eligible). Patients without available biopsies (n = 1), with insufficient tumor epithelial cells (n = 10), or insufficient DNA yield (n = 5) were excluded from the analysis. Molecular subtype and tumor grade were abstracted from a medical records’ review. Ten IBC tumors were estrogen-receptor-positive (ER+) and human epidermal growth factor receptor 2 (HER2)-negative (n = 10 out of 14). Sufficient RNA and DNA were simultaneously extracted from 14 biopsy specimens using the Qiagen AllPrep Kit. RNA was amplified using the Sensation kit and profiled using the Affymetrix Human Transcriptome Array 2.0. DNA was profiled for genome-wide copy number variation (CNV) using the Affymetrix OncoScan Array and analyzed using the Nexus Chromosome Analysis Suite. Among the 14 eligible samples, we first confirmed biological concordance and quality control metrics using replicates and gene expression data. Second, we examined CNVs and gene expression change by IBC subtype. We identified significant CNVs in IBC patients after adjusting for multiple comparisons. Next, to assess whether the CNVs were unique to IBC, we compared the IBC CNV data to fresh-frozen non-IBC CNV data from The Cancer Genome Atlas (n = 388). On chromosome 7p11.2, we identified significant CN gain located at position 58,019,983-58,025,423 in 8 ER+ IBC samples compared to 338 non-IBC ER+ samples (region length: 5440 bp gain and 69,039 bp, False Discovery Rate (FDR) p-value = 3.12 × 10−10) and at position 57,950,944–58,025,423 in 3 TN-IBC samples compared to 50 non-IBC TN samples (74,479 base pair, gain, FDR p-value = 4.27 × 10−5; near the EGFR gene). We also observed significant CN loss on chromosome 21, located at position 9,648,315–9,764,385 (p-value = 4.27 × 10−5). Secondarily, differential gene expression in IBC patients with 7p11.2 CN gain compared to SUM149 were explored after FDR correction for multiple testing (p-value = 0.0016), but the results should be interpreted with caution due to the small sample size. Finally, the data presented are hypothesis-generating. Validation of CNVs that contribute to the unique presentation and biological features associated with IBC in larger datasets may lead to the optimization of treatment strategies.

Stabilization of E-cadherin adhesions by COX-2/GSK3β signaling is a targetable pathway in metastatic breast cancer

Metastatic progression of epithelial cancers can be associated with epithelial-mesenchymal transition (EMT) including transcriptional inhibition of E-cadherin (CDH1) expression. Recently, EM plasticity (EMP) and E-cadherin-mediated, cluster-based metastasis and treatment resistance have become more appreciated. However, the mechanisms that maintain E-cadherin expression in this context are less understood. Through studies of inflammatory breast cancer (IBC) and a 3D tumor cell "emboli" culture paradigm, we discovered that cyclooxygenase 2 (COX-2; PTGS2), a target gene of C/EBPδ (CEBPD), or its metabolite prostaglandin E2 (PGE2) promotes protein stability of E-cadherin, β-catenin, and p120 catenin through inhibition of GSK3β. The COX-2 inhibitor celecoxib downregulated E-cadherin complex proteins and caused cell death. Coexpression of E-cadherin and COX-2 was seen in breast cancer tissues from patients with poor outcome and, along with inhibitory GSK3β phosphorylation, in patient-derived xenografts (PDX) including triple negative breast cancer (TNBC).Celecoxib alone decreased E-cadherin protein expression within xenograft tumors, though CDH1 mRNA levels increased, and reduced circulating tumor cell (CTC) clusters. In combination with paclitaxel, celecoxib attenuated or regressed lung metastases. This study has uncovered a mechanism by which metastatic breast cancer cells can maintain E-cadherin-mediated cell-to-cell adhesions and cell survival, suggesting that some patients with COX-2+/E-cadherin+ breast cancer may benefit from targeting of the PGE2 signaling pathway.

Comparative transcriptional analyses of preclinical models and patient samples reveal MYC and RELA driven expression patterns that define the molecular landscape of IBC

Inflammatory breast cancer (IBC) is an aggressive disease for which the spectrum of preclinical models was rather limited in the past. More recently, novel cell lines and xenografts have been developed. This study evaluates the transcriptome of an extended series of IBC preclinical models and performed a comparative analysis with patient samples to determine the extent to which the current models recapitulate the molecular characteristics of IBC observed clinically. We demonstrate that the IBC preclinical models are exclusively estrogen receptor (ER)-negative and of the basal-like subtype, which reflects to some extent the predominance of these subtypes in patient samples. The IBC-specific 79-signature we previously reported was retrained and discriminated between IBC and non-IBC preclinical models, but with a relatively high rate of false positive predictions. Further analyses of gene expression profiles revealed important roles for cell proliferation, MYC transcriptional activity, and TNFɑ/NFκB in the biology of IBC. Patterns of MYC expression and transcriptional activity were further explored in patient samples, which revealed interactions with ESR1 expression that are contrasting in IBC and nIBC and notable given the comparatively poor outcomes of ER+ IBC. Our analyses also suggest important roles for NMYC, MXD3, MAX, and MLX in shaping MYC signaling in IBC. Overall, we demonstrate that the IBC preclinical models can be used to unravel cancer cell intrinsic molecular features, and thus constitute valuable research tools. Nevertheless, the current lack of ER-positive IBC models remains a major hurdle, particularly since interactions with the ER pathway appear to be relevant for IBC.

TF-Marker: a comprehensive manually curated database for transcription factors and related markers in specific cell and tissue types in human

Transcription factors (TFs) play key roles in biological processes and are usually used as cell markers. The emerging importance of TFs and related markers in identifying specific cell types in human diseases increases the need for a comprehensive collection of human TFs and related markers sets. Here, we developed the TF-Marker database (TF-Marker, http://bio.liclab.net/TF-Marker/), aiming to provide cell/tissue-specific TFs and related markers for human. By manually curating thousands of published literature, 5905 entries including information about TFs and related markers were classified into five types according to their functions: (i) TF: TFs which regulate expression of the markers; (ii) T Marker: markers which are regulated by the TF; (iii) I Marker: markers which influence the activity of TFs; (iv) TFMarker: TFs which play roles as markers and (v) TF Pmarker: TFs which play roles as potential markers. The 5905 entries of TF-Marker include 1316 TFs, 1092 T Markers, 473 I Markers, 1600 TFMarkers and 1424 TF Pmarkers, involving 383 cell types and 95 tissue types in human. TF-Marker further provides a user-friendly interface to browse, query and visualize the detailed information about TFs and related markers. We believe TF-Marker will become a valuable resource to understand the regulation patterns of different tissues and cells.

LncRNA MIR205HG regulates melanomagenesis via the miR-299-3p/VEGFA axis

In this study, we investigated the role of lncRNA MIR205HG in melanomagenesis. Quantitative real-time PCR (qRT-PCR) analysis showed that MIR205HG levels were significantly upregulated in melanoma cell lines compared to normal human melanocytes. Similarly, MIR205HG levels were significantly higher melanoma tissues than adjacent normal skin tissues (n=30). CCK-8 and flow cytometry assays showed that MIR205HG knockdown significantly decreased the viability of melanoma cells. Dual luciferase reporter and RNA pull-down assays confirmed that MIR205HG directly binds to microRNA (miR)-299-3p. Targetscan analysis and dual luciferase reporter assays showed that miR-299-3p directly binds to the 3'UTR of VEGFA mRNA. Wound healing and transwell invasion assays showed that MIR205HG knockdown decreased in vitro migration and invasiveness of melanoma cells, and these effects were reversed by treatment with miR-299-3p inhibitor. MIR205HG-silenced melanoma cells showed increased miR-299-3p expression and lower levels of both VEGFA mRNA and protein. Tumor volumes were significantly smaller in nude mice xenografted with MIR205HG knockdown melanoma cells than the controls. These results demonstrate that MIR205HG supports melanoma growth via the miR-299-3p/VEGFA axis. This makes MIR205HG a potential therapeutic target for the treatment of melanoma.

Interplay between tumor microenvironment and partial EMT as the driver of tumor progression

Epithelial-to-mesenchymal transition (EMT), an evolutionary conserved phenomenon, has been extensively studied to address the unresolved variable treatment response across therapeutic regimes in cancer subtypes. EMT has long been envisaged to regulate tumor invasion, migration, and therapeutic resistance during tumorigenesis. However, recently it has been highlighted that EMT involves an intermediate partial EMT (pEMT) phenotype, defined by incomplete loss of epithelial markers and incomplete gain of mesenchymal markers. It has been further emphasized that pEMT transition involves a spectrum of intermediate hybrid states on either side of pEMT spectrum. Emerging evidence underlines bi-directional crosstalk between tumor cells and surrounding microenvironment in acquisition of pEMT phenotype. Although much work is still ongoing to gain mechanistic insights into regulation of pEMT phenotype, it is evident that pEMT plays a critical role in tumor aggressiveness, invasion, migration, and metastasis along with therapeutic resistance. In this review, we focus on important role of tumor-intrinsic factors and tumor microenvironment in driving pEMT and emphasize that engineered controlled microenvironments are instrumental to provide mechanistic insights into pEMT biology. We also discuss the significance of pEMT in regulating hallmarks of tumor progression i.e. cell cycle regulation, collective migration, and therapeutic resistance. Although constantly evolving, current progress and momentum in the pEMT field holds promise to unravel new therapeutic targets to halt tumor progression at early stages as well as tackle the complex therapeutic resistance observed across many cancer types.

•

Partial EMT phenotype drives key hallmarks of tumor progression

•

Role of tumor microenvironment in pEMT phenotype via cellular signaling pathways

•

Engineering 3D in vitro models to study pEMT phenotype

•

Opportunities and challenges in understanding pEMT phenotype

Decorin-mediated suppression of tumorigenesis, invasion, and metastasis in inflammatory breast cancer

Inflammatory breast cancer (IBC) is a clinically distinct and highly aggressive form of breast cancer with rapid onset and a strong propensity to metastasize. The molecular mechanisms underlying the aggressiveness and metastatic propensity of IBC are largely unknown. Herein, we report that decorin (DCN), a small leucine-rich extracellular matrix proteoglycan, is downregulated in tumors from patients with IBC. Overexpression of DCN in IBC cells markedly decreased migration, invasion, and cancer stem cells in vitro and inhibited tumor growth and metastasis in IBC xenograft mouse models. Mechanistically, DCN functioned as a suppressor of invasion and tumor growth in IBC by destabilizing E-cadherin and inhibiting EGFR/ERK signaling. DCN physically binds E-cadherin in IBC cells and accelerates its degradation through an autophagy-linked lysosomal pathway. We established that DCN inhibits tumorigenesis and metastasis in IBC cells by negatively regulating the E-cadherin/EGFR/ERK axis. Our findings offer a potential therapeutic strategy for IBC, and provide a novel mechanism for IBC pathobiology.

Xiaoding Hu et al. find that expression of the proteoglycan decorin is decreased in patients with inflammatory breast cancer compared to normal breast tissue and some other types of breast cancer. They demonstrate that decorin acts as a tumor suppressor in cancer cells and human xenograft mouse models by destabilizing the E-cadherin-EGFR signaling axis, and their findings suggest potential therapeutic strategies for this aggressive breast cancer.

Hypoxia, partial EMT and collective migration: Emerging culprits in metastasis

Epithelial-mesenchymal transition (EMT) is a cellular biological process involved in migration of primary cancer cells to secondary sites facilitating metastasis. Besides, EMT also confers properties such as stemness, drug resistance and immune evasion which can aid a successful colonization at the distant site. EMT is not a binary process; recent evidence suggests that cells in partial EMT or hybrid E/M phenotype(s) can have enhanced stemness and drug resistance as compared to those undergoing a complete EMT. Moreover, partial EMT enables collective migration of cells as clusters of circulating tumor cells or emboli, further endorsing that cells in hybrid E/M phenotypes may be the 'fittest' for metastasis. Here, we review mechanisms and implications of hybrid E/M phenotypes, including their reported association with hypoxia. Hypoxia-driven activation of HIF-1α can drive EMT. In addition, cyclic hypoxia, as compared to acute or chronic hypoxia, shows the highest levels of active HIF-1α and can augment cancer aggressiveness to a greater extent, including enriching for a partial EMT phenotype. We also discuss how metastasis is influenced by hypoxia, partial EMT and collective cell migration, and call for a better understanding of interconnections among these mechanisms. We discuss the known regulators of hypoxia, hybrid EMT and collective cell migration and highlight the gaps which needs to be filled for connecting these three axes which will increase our understanding of dynamics of metastasis and help control it more effectively.

Inflammatory Breast Cancer: Clinical Implications of Genomic Alterations and Mutational Profiling

Simple Summary

Inflammatory breast cancer (IBC) is an aggressive disease with high mortality rates. Nowadays, there is no targeted treatment for this tumor type. Based on this context, we investigated the molecular profile of this disease by using well-established methodologies (high-resolution microarray platform, targeted next-generation sequencing, and immunohistochemistry) that have proven potential to unveil cancer biomarkers. We found alterations related to IBC aggressiveness and metastasis (gains of MDM4, losses of CHL1, and high homologous recombination deficiency scores), and worse overall survival (variants in HR and mismatch repair genes). We also compared the mutational profiling of our cases with literature data, which includes both non-IBC and IBC cases, validating our findings. Overall, we describe genetic alterations with the potential to be used as prognostic or predictive biomarkers and ultimately improve IBC patients’ care.

Abstract

Inflammatory breast cancer (IBC) is a rare and aggressive type of breast cancer whose molecular basis is poorly understood. We performed a comprehensive molecular analysis of 24 IBC biopsies naïve of treatment, using a high-resolution microarray platform and targeted next-generation sequencing (105 cancer-related genes). The genes more frequently affected by gains were MYC (75%) and MDM4 (71%), while frequent losses encompassed TP53 (71%) and RB1 (58%). Increased MYC and MDM4 protein expression levels were detected in 18 cases. These genes have been related to IBC aggressiveness, and MDM4 is a potential therapeutic target in IBC. Functional enrichment analysis revealed genes associated with inflammatory regulation and immune response. High homologous recombination (HR) deficiency scores were detected in triple-negative and metastatic IBC cases. A high telomeric allelic imbalance score was found in patients having worse overall survival (OS). The mutational profiling was compared with non-IBC (TCGA, n = 250) and IBC (n = 118) from four datasets, validating our findings. Higher frequency of TP53 and BRCA2 variants were detected compared to non-IBC, while PIKC3A showed similar frequency. Variants in mismatch repair and HR genes were associated with worse OS. Our study provided a framework for improved diagnosis and therapeutic alternatives for this aggressive tumor type.

Age-related DNA methylation in paired normal and tumour breast tissue in Chinese breast cancer patients

Age-related DNA methylation is a potential mechanism contributing to breast cancer development. Studies of primarily Caucasian women have identified many CpG sites of age-related methylation in non-diseased breast tissue possibly driving cancer development over time. There is a paucity of studies involving Asian women whose ages at breast cancer onset are usually younger than Caucasians. We identified the 181 most consistent age-related methylation events in non-diseased breast tissue across published studies. Age-related methylation events were measured in adjacent normal and breast tumour tissue in an exclusively Asian population at the previously identified age-related methylation sites. Age-related methylation was found in 118 probes in adjacent normal breast tissue. Methylation of 99% of these sites was increased with age and predominantly located on CpG islands in promoter regions. To ascertain biological relevance to breast cancer, we focused on the 37 sites with overall higher methylation in tumour compared to adjacent normal samples. Some sites positively related to age, including AQP5 and CORO6, inversely correlated with gene expression. Several others have known involvement in suppression of carcinogenesis including GPC5 and SST, suggesting that perturbation of epigenetic regulation at these sites due to ageing may contribute to the progression of carcinogenesis. This study highlights an age-related methylation landscape in non-tumour tissue, consistent not just across studies, but also across different populations. We present candidate age-related methylation sites warranting further investigation as potential epigenetic drivers of breast cancer. They may serve as potential targets of site-specific demethylation intervention strategies for the prevention of age-related breast cancer.

miR-16-5p Suppresses Progression and Invasion of Osteosarcoma via Targeting at Smad3

Background

MicroRNAs are known to regulate carcinogenesis of osteosarcoma. Although, miR-16-5p is known to exert inhibitory effects on several forms of cancers, its effects on the growth and invasion of osteosarcoma have not been studied.

Methods

We collected human osteosarcoma specimens and adjacent tissues to detect the expression of miR-16-5p by real-time polymerase chain reaction, immunoblotting, and immunohistochemistry. The proliferation, migration, and invasion of MG63 and HOS cells following miR-16-5p overexpression and inhibition were detected with cell counting kit-8, wound healing assay, and Transwell assay, respectively. An expression vector carrying a mutated 3'-untranslated region of mothers against decapentaplegic homolog 3 (Smad3) was constructed.

Results

The results showed that miR-16-5p expression was downregulated in osteosarcoma tissues and cells as compared with adjacent counterparts, while Smad3 was overexpressed in osteosarcoma cells. The overexpression of miR-16-5p resulted in the inhibition of the proliferation, migration, and invasion of osteosarcoma cells and enhanced the therapeutic effect of cisplatin. These effects were attenuated with miR-16-5p expression inhibition. In cells transfected with miR-16-5p mimic, Smad3 expression decreased, while this effect was absent in the cells carrying mutated Smad3.

Conclusions

Therefore, miR-16-5p inhibits the growth and invasion of osteosarcoma by targeting Smad3.

A high neutrophil-lymphocyte ratio and platelet-lymphocyte ratio are associated with a worse outcome in inflammatory breast cancer

Introduction

Inflammatory breast cancer (IBC) is an uncommon, but aggressive form of breast cancer that accounts for a disproportionally high fraction of breast cancer related mortality. The aim of this study was to explore the peripheral immune response and the prognostic value of blood-based biomarkers, such as the neutrophil-to-lymphocyte ratio (NLR), in a large IBC cohort.

Patients & methods

We retrospectively identified 127 IBC patients and collected lab results from in-hospital medical records. The differential count of leukocytes was determined at the moment of diagnosis, before any therapeutic intervention. A cohort of early stage (n = 108), locally advanced (n = 74) and metastatic breast cancer patients (n = 41) served as a control population.

Results

The NLR was significantly higher in IBC compared to an early stage breast cancer cohort, but no difference between IBC patients and locally advanced breast cancer patients was noted. In the metastatic setting, there was also no significant difference between IBC and nIBC. However, a high NLR (>4.0) remained a significant predictor of worse outcome in IBC patients (HR: 0.49; 95% CI: 0.24–1.00; P = .05) and a lower platelet-lymphocyte ratio (PLR) (≤210) correlated with a better disease-free survival (DFS) (HR: 0.51; 95% CI: 0.28–0.93; P = .03).

Conclusion

Patients with a high NLR (>4.0) have a worse overall prognosis in IBC, while the PLR correlated with relapse free survival (RFS). Since NLR and PLR were not specifically associated with IBC disease, they can be seen as markers of more extensive disease.

•

There is no association between NLR or PLR and inflammatory breast cancer (IBC).

•

IBC and non-inflammatory breast cancer elicit a similar peripheral immune response.

•

A high neutrophil-to-lymphocyte ratio (NLR) is associated with a worse overall survival in IBC.

•

A high platelet-lymphocyte ratio (PLR) correlates with a worse disease-free survival in IBC.

•

An elevated PLR or NLR should be seen as a marker of more extensive disease in IBC.