Activation of ERα signaling differentially modulates IFN-γ induced HLA-class II expression in breast cancer cells

Advances in predicting breast cancer driver mutations: Tools for precision oncology (Review)

In the modern era of medicine, prognosis and treatment, options for a number of cancer types including breast cancer have been improved by the identification of cancer‑specific biomarkers. The availability of high‑throughput sequencing and analysis platforms, the growth of publicly available cancer databases and molecular and histological profiling facilitate the development of new drugs through a precision medicine approach. However, only a fraction of patients with breast cancer with few actionable mutations typically benefit from the precision medicine approach. In the present review, the current development in breast cancer driver gene identification, actionable breast cancer mutations, as well as the available therapeutic options, challenges and applications of breast precision oncology are systematically described. Breast cancer driver mutation‑based precision oncology helps to screen key drivers involved in disease development and progression, drug sensitivity and the genes responsible for drug resistance. Advances in precision oncology will provide more targeted therapeutic options for patients with breast cancer, improving disease‑free survival and potentially leading to significant successes in breast cancer treatment in the near future. Identification of driver mutations has allowed new targeted therapeutic approaches in combination with standard chemo‑ and immunotherapies in breast cancer. Developing new driver mutation identification strategies will help to define new therapeutic targets and improve the overall and disease‑free survival of patients with breast cancer through efficient medicine.

Coordinated inflammation and immune response transcriptional regulation in breast cancer molecular subtypes

Breast cancer, characterized by its complexity and diversity, presents significant challenges in understanding its underlying biology. In this study, we employed gene co-expression network analysis to investigate the gene composition and functional patterns in breast cancer subtypes and normal breast tissue. Our objective was to elucidate the detailed immunological features distinguishing these tumors at the transcriptional level and to explore their implications for diagnosis and treatment. The analysis identified nine distinct gene module clusters, each representing unique transcriptional signatures within breast cancer subtypes and normal tissue. Interestingly, while some clusters exhibited high similarity in gene composition between normal tissue and certain subtypes, others showed lower similarity and shared traits. These clusters provided insights into the immune responses within breast cancer subtypes, revealing diverse immunological functions, including innate and adaptive immune responses. Our findings contribute to a deeper understanding of the molecular mechanisms underlying breast cancer subtypes and highlight their unique characteristics. The immunological signatures identified in this study hold potential implications for diagnostic and therapeutic strategies. Additionally, the network-based approach introduced herein presents a valuable framework for understanding the complexities of other diseases and elucidating their underlying biology.

The breast cancer tumor microenvironment and precision medicine: immunogenicity and conditions favoring response to immunotherapy

Some main recent researches that have dissected tumor microenvironment (TME) by imaging mass cytometry (IMC) in different subtypes of primary breast cancer samples were considered. The many phenotypic variants, clusters of epithelial tumor and immune cells, their structural features as well as the main genetic aberrations, sub-clonal heterogeneity and their systematic classification also have been examined. Mutational evolution has been assessed in primary and metastatic breast cancer samples. Overall, based on these findings the current concept of precision medicine is questioned and challenged by alternative therapeutic strategies. In the last two decades, immunotherapy as a powerful and harmless tool to fight cancer has received huge attention. Thus, the tumor immune microenvironment (TIME) composition, its prognostic role for clinical course as well as a novel definition of immunogenicity in breast cancer are proposed. Investigational clinical trials carried out by us and other findings suggest that G0-G1 state induced in endocrine-dependent metastatic breast cancer is more suitable for successful immune manipulation. Residual micro-metastatic disease seems to be another specific condition that can significantly favor the immune response in breast and other solid tumors.

Experimental and clinical evidence in favour of an effective immune stimulation in ER-positive, endocrine-dependent metastatic breast cancer

In ER+ breast cancer, usually seen as the low immunogenic type, the main mechanisms favouring the immune response or tumour growth and immune evasion in the tumour microenvironment (TME) have been examined. The principal implications of targeting the oestrogen-mediated pathways were also considered. Recent experimental findings point out that anti-oestrogens contribute to the reversion of the immunosuppressive TME. Moreover, some preliminary clinical data with the hormone-immunotherapy association in a metastatic setting support the notion that the reversion of immune suppression in TME is likely favoured by the G0-G1 state induced by anti-oestrogens. Following immune stimulation, the reverted immune suppression allows the boosting of the effector cells of the innate and adaptive immune response. This suggests that ER+ breast cancer is a molecular subtype where a successful active immune manipulation can be attained. If this is confirmed by a prospective multicentre trial, which is expected in light of the provided evidence, the proposed hormone immunotherapy can also be tested in the adjuvant setting. Furthermore, the different rationale suggests a synergistic activity of our proposed immunotherapy with the currently recommended regimen consisting of antioestrogens combined with cyclin kinase inhibitors. Overall, this lays the foundation for a shift in clinical practice within this most prevalent molecular subtype of breast cancer.

Revealing Propolis Potential Activity on Inhibiting Estrogen Receptor and Heat Shock Protein 90 Overexpressed in Breast Cancer by Bioinformatics Approaches

Breast cancer is the most commonly diagnosed cancer globally, with the highest incidence of breast cancer occurring in Asian countries including Indonesia. Among the types of breast cancer, the estrogen receptor (ER)-positive subtype which is prominent with estrogen receptor alpha (ERα) and heat shock protein 90 (HSP90) overexpression genes becomes the most prevalent than the others, approximately 75% of all breast cancer cases. ERα and HSP90 play a role in breast cancer activities including breast tumor growth, invasion, and metastasis mechanism. Propolis, a natural bee product, has been explored for its anticancer activity. However, there is lack of studies that evaluated the potential inhibitor from propolis compounds to the ERα and HSP90 proteins. Therefore, this article focuses on examining the correlation between ERα and HSP90's role in breast cancer and investigating the potential of 93 unique propolis compositions in inhibiting these genes in breast cancer using in silico approaches. This study revealed the positive correlation between ERα and HSP90 genes in breast cancer disease development. Furthermore, we also found novel potential bioactive compounds of propolis against breast cancer through binding with ERα and HSP90; they were 3',4',7-trihydroxyisoflavone and baicalein-7-O-β-D glucopyranoside, respectively. Further research on these compounds is needed to elucidate deeper mechanisms and activity in the real biological system to develop new breast cancer drug treatments.

Estrogen receptor α-mediated signaling inhibits type I interferon response to promote breast carcinogenesis

Estrogen receptor α (ERα) is an important driver and therapeutic target in ∼70% of breast cancers. How ERα drives breast carcinogenesis is not fully understood. In this study, we show that ERα is a negative regulator of type I interferon (IFN) response. Activation of ERα by its natural ligand estradiol inhibits IFN-β-induced transcription of downstream IFN-stimulated genes (ISGs), whereas ERα deficiency or the stimulation with its antagonist fulvestrant has opposite effects. Mechanistically, ERα induces the expression of the histone 2A variant H2A.Z to restrict the engagement of the IFN-stimulated gene factor 3 (ISGF3) complex to the promoters of ISGs and also interacts with STAT2 to disrupt the assembly of the ISGF3 complex. These two events mutually lead to the inhibition of ISG transcription induced by type I IFNs. In a xenograft mouse model, fulvestrant enhances the ability of IFN-β to suppress ERα+ breast tumor growth. Consistently, clinical data analysis reveals that ERα+ breast cancer patients with higher levels of ISGs exhibit higher long-term survival rates. Taken together, our findings suggest that ERα inhibits type I IFN response via two distinct mechanisms to promote breast carcinogenesis.

Differential expression of the inflammatory ciita gene may be accompanied by altered bone properties in intact sex steroid-deficient female rats

OBJECTIVE

The class II transactivator (CIITA), encoded by the CIITA gene, controls expression of immune response regulators, which affect bone homeostasis. Previously, we investigated a functional CIITA polymorphism in elderly women. Women carrying the allele associated with lower CIITA levels displayed higher bone mineral density (BMD), but also higher bone loss. The present exploratory study in a rat model sought to investigate effects of differential expression of Ciita on bone structural integrity and strength. Two strains DA (normal-to-high expression) and DA.VRA4 (lower expression) underwent ovariectomy (OVX) or sham-surgery at ~ 14-weeks of age (DA OVX n = 8, sham n = 4; DA.VRA4 OVX n = 10, sham n = 2). After 16-weeks, femoral BMD and bone mineral content (BMC) were measured and morphometry and biomechanical testing performed.

RESULTS

In DA.VRA4 rats, BMD/BMC, cross-sectional area and biomechanical properties were lower. Ciita expression was accompanied by OVX-induced changes to cross-sectional area and femoral shaft strength; DA rats had lower maximum load-to-fracture. Thus, while lower Ciita expression associated with lower bone mass, OVX induced changes to structural and mechanical bone properties were less pronounced.

CONCLUSION

The data tentatively suggests association between Ciita expression and structural and mechanical bone properties, and a possible role in bone changes resulting from estrogen deficiency.

Uncovering the complex role of interferon-gamma in suppressing type 2 immunity to cancer

Cancer involves cells' abnormal growth and ability to invade or metastasize to different body parts. Cancerous cells can divide uncontrollably and spread to other areas through the lymphatic or circulatory systems. Tumors form when malignant cells clump together in an uncontrolled manner. In this context, the cytokine interferon-gamma (IFN-γ) is crucial in regulating immunological responses, particularly malignancy. While IFN-γ is well-known for its potent anti-tumor effects by activating type 1 immunity, recent research has revealed its ability to suppress type 2 immunity, associated with allergy and inflammatory responses. This review aims to elucidate the intricate function of IFN-γ in inhibiting type 2 immune responses to cancer. We explore how IFN-γ influences the development and function of immune cells involved in type 2 immunity, such as mast cells, eosinophils, and T-helper 2 (Th2) cells. Additionally, we investigate the impact of IFN-mediated reduction of type 2 immunity on tumor development, metastasis, and the response to immunotherapeutic interventions. To develop successful cancer immunotherapies, it is crucial to comprehend the complex interplay between type 2 and type 1 immune response and the regulatory role of IFN-γ. This understanding holds tremendous promise for the development of innovative treatment approaches that harness the abilities of both immune response types to combat cancer. However, unraveling the intricate interplay between IFN-γ and type 2 immunity in the tumor microenvironment will be essential for achieving this goal.

Dishevelled 2 regulates cancer cell proliferation and T cell mediated immunity in HER2-positive breast cancer

BACKGROUND

Dishevelled paralogs (DVL1, 2, 3) are key mediators of Wnt pathway playing a role in constitutive oncogenic signaling influencing the tumor microenvironment. While previous studies showed correlation of β-catenin with T cell gene expression, little is known about the role of DVL2 in modulating tumor immunity. This study aimed to uncover the novel interaction between DVL2 and HER2-positive (HER2+) breast cancer (BC) in regulating tumor immunity and disease progression.

METHODS

DVL2 loss of function studies were performed with or without a clinically approved HER2 inhibitor, Neratinib in two different HER2+ BC cell lines. We analyzed RNA (RT-qPCR) and protein (western blot) expression of classic Wnt markers and performed cell proliferation and cell cycle analyses by live cell imaging and flow cytometry, respectively. A pilot study in 24 HER2+ BC patients was performed to dissect the role of DVL2 in tumor immunity. Retrospective chart review on patient records and banked tissue histology were performed. Data were analyzed in SPSS (version 25) and GraphPad Prism (version 7) at a significance p < 0.05.

RESULTS

DVL2 regulates the transcription of immune modulatory genes involved in antigen presentation and T cell maintenance. DVL2 loss of function down regulated mRNA expression of Wnt target genes involved in cell proliferation, migration, invasion in HER2+ BC cell lines (±Neratinib). Similarly, live cell proliferation and cell cycle analyses reveal that DVL2 knockdown (±Neratinib) resulted in reduced proliferation, higher growth arrest (G1), limited mitosis (G2/M) compared to non-targeted control in one of the two cell lines used. Analyses on patient tissues who received neoadjuvant chemotherapy (n = 14) further demonstrate that higher DVL2 expression at baseline biopsy pose a significant negative correlation with % CD8α levels (r = - 0.67, p < 0.05) while have a positive correlation with NLR (r = 0.58, p < 0.05), where high NLR denotes worse cancer prognosis. These results from our pilot study reveal interesting roles of DVL2 proteins in regulating tumor immune microenvironment and clinical predictors of survival in HER2+ BC.

CONCLUSION

Our study demonstrates potential immune regulatory role of DVL2 proteins in HER2+ BC. More in-depth mechanistic studies of DVL paralogs and their influence on anti-tumor immunity may provide insight into DVLs as potential therapeutic targets benefiting BC patients.

Expression of hormone receptors is associated with specific immunological profiles of the breast cancer microenvironment

BACKGROUND

Elucidating the unique immunoregulatory mechanisms in breast cancer microenvironment may help develop new therapeutic strategies. Some studies have suggested that hormone receptors also have immune regulatory functions, but their mechanisms are not fully understood. In this study, we have comprehensively analyzed the relationship between the expressions of estrogen (ER), progesterone (PgR), and androgen receptors (AR), and the immunological profile in breast cancer.

METHODS

Using publicly available gene expression profile datasets, METABRIC and SCAN-B, the associations between the expressions of hormone receptors and the immune cell compositions in breast cancer tissue, estimated by CIBERSORTx algorithm, were analyzed. We histologically evaluated tumor-infiltrating lymphocytes (hTIL), PD-L1 (hPD-L1) expression, and the infiltration of 11 types of immune cells by flow cytometry (FCM) for 45 breast cancer tissue samples. The relationships between them and the expressions of ER, PgR, and AR of tumor tissues, evaluated immunohistochemically, were analyzed.

RESULTS

Expressions of ESR1, PGR, and AR were negatively correlated with overall immune composition. Expressions of ER and AR, but not that of PgR, were inversely associated with hTIL and hPD-L1 expression. FCM analysis showed that the expressions of ER and AR, but not that of PgR, were associated with decreased total leukocyte infiltration. Both CIBERSORTx and FCM analysis showed that ER expression was associated with reduced infiltration of macrophages and CD4+ T cells and that of AR with reduced macrophage infiltration.

CONCLUSION

Hormone receptor expression correlates with specific immunological profiles in the breast cancer microenvironment both at the gene and protein expression levels.

Multiplexed In Situ Spatial Protein Profiling in the Pursuit of Precision Immuno-Oncology for Patients with Breast Cancer

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of many solid tumors. In breast cancer (BC), immunotherapy is currently approved in combination with chemotherapy, albeit only in triple-negative breast cancer. Unfortunately, most patients only derive limited benefit from ICIs, progressing either upfront or after an initial response. Therapeutics must engage with a heterogeneous network of complex stromal-cancer interactions that can fail at imposing cancer immune control in multiple domains, such as in the genomic, epigenomic, transcriptomic, proteomic, and metabolomic domains. To overcome these types of heterogeneous resistance phenotypes, several combinatorial strategies are underway. Still, they can be predicted to be effective only in the subgroups of patients in which those specific resistance mechanisms are effectively in place. As single biomarker predictive performances are necessarily suboptimal at capturing the complexity of this articulate network, precision immune-oncology calls for multi-omics tumor microenvironment profiling in order to identify unique predictive patterns and to proactively tailor combinatorial treatments. Multiplexed single-cell spatially resolved tissue analysis, through precise epitope colocalization, allows one to infer cellular functional states in view of their spatial organization. In this review, we discuss-through the lens of the cancer-immunity cycle-selected, established, and emerging markers that may be evaluated in multiplexed spatial protein panels to help identify prognostic and predictive patterns in BC.

CD47 expression and tumor-associated immune cells in breast cancer and their correlation with molecular subtypes and prognostic factors

OBJECTIVE

Breast cancer is the most common malignancy in women and a heterogeneous disease at the molecular level. Since most breast cancer cases are not of a special type, it is suggested that tumor-associated macrophages and tumor-infiltrating lymphocytes, which are involved in tumor growth, invasion, angiogenesis, and metastasis, may be important factors that should be evaluated together with standard criteria to determine the prognosis of cancer and assist in treatment decisions and outcome stratification. In this study, CD47 expression, which is involved in macrophage-mediated immune escape, tumor-infiltrating lymphocytes, and tumor-associated macrophages were evaluated in breast cancer molecular subgroups and correlated with prognostic factors.

MATERIAL AND METHOD

The immunohistochemistry of CD47, CD163, and CD3 was analyzed on the tissue microarrays of 278 invasive breast cancer cases.

RESULTS

The CD47, CD163, and CD3 expressions were found to be correlated with various clinicopathological parameters in breast cancer. High levels of CD47, CD163, and CD3 expressions had a significant correlation with the ER status and PR status, Ki-67 proliferation index, and molecular subtype (P < 0.05). The CD47 expression had a significant correlation with the CD3 and CD163 expressions (p = 0.021 and p = 0.001, respectively).

CONCLUSIONS

Our results suggest that CD47, CD163, and CD3 may be among the prognostic factors of breast cancer. The combined use of CD47, CD163, and CD3 can be a new prognostic factor for patients with breast cancer, especially as a therapeutic target in hormone receptor-negative breast cancer cases and those with a high proliferation index.

The Association of Estrogen Receptor Activity, Interferon Signaling, and MHC Class I Expression in Breast Cancer

PURPOSE

The expression of major histocompatibility complex class I (MHC I) has previously been reported to be negatively associated with estrogen receptor (ER) expression. Furthermore, MHC I expression, level of tumor-infiltrating lymphocytes (TILs), and expression of interferon (IFN) mediator MxA are positively associated with one another in human breast cancers. This study aimed to investigate the mechanisms of association of MHC I with ER and IFN signaling.

MATERIALS AND METHODS

The human leukocyte antigen (HLA)-ABC protein expression was analyzed in breast cancer cell lines. The expressions of HLA-A and MxA mRNAs were analyzed in MCF-7 cells in Gene Expression Omnibus (GEO) data. ER and HLA-ABC expressions, Ki-67 labeling index and TIL levels in tumor tissue were also analyzed in ER+/ human epidermal growth factor receptor 2 (HER2)- breast cancer patients who randomly received either neoadjuvant chemotherapy or estrogen modulator treatment followed by resection.

RESULTS

HLA-ABC protein expression was decreased after β-estradiol treatment or hESR-GFP transfection and increased after fulvestrant or IFN-γ treatment in cell lines. In GEO data, HLA-A and MxA expression was increased after ESR1 shRNA transfection. In patients, ER Allred score was significantly lower and the HLA-ABC expression, TIL levels, and Ki-67 were significantly higher in the estrogen modulator treated group than the chemotherapy treated group.

CONCLUSION

MHC I expression and TIL levels might be affected by ER pathway modulation and IFN treatment. Further studies elucidating the mechanism of MHC I regulation could suggest a way to boost TIL influx in cancer in a clinical setting.

Free ISG15 and protein ISGylation emerging in SARS-CoV-2 infection

Interferon-simulated gene 15 (ISG15) belongs to the family of ubiquitin-like proteins. ISG15 acts as a cytokine and modifies proteins through ISGylation. This posttranslational modification has been associated with antiviral and immune response pathways. In addition, it is known that the genome of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) encodes proteases critical for viral replication. Consequently, these proteases are also central in the progression of coronavirus disease 2019 (COVID-19). Interestingly, the protease SARS-CoV-2-PLpro removes ISG15 from ISGylated proteins such as IRF3 and MDA5, affecting immune and antiviral defense from the host. Here, the implications of ISG15, ISGylation, and generation of SARS-CoV-2-PLpro inhibitors in SARS-CoV-2 infection are discussed.

Interferon Signaling in Estrogen Receptor-positive Breast Cancer: A Revitalized Topic

Cancer immunology is the most rapidly expanding field in cancer research, with the importance of immunity in cancer pathogenesis now well accepted including in the endocrine-related cancers. The immune system plays an essential role in the development of ductal and luminal epithelial differentiation in the mammary gland. Originally identified as evolutionarily conserved antipathogen cytokines, interferons (IFNs) have shown important immune-modulatory and antineoplastic properties when administered to patients with various types of cancer, including breast cancer. Recent studies have drawn attention to the role of tumor- and stromal-infiltrating lymphocytes in dictating therapy response and outcome of breast cancer patients, which, however, is highly dependent on the breast cancer subtype. The emerging role of tumor cell-inherent IFN signaling in the subtype-defined tumor microenvironment could influence therapy response with protumor activities in breast cancer. Here we review evidence with new insights into tumor cell-intrinsic and tumor microenvironment-derived IFN signaling, and the crosstalk of IFN signaling with key signaling pathways in estrogen receptor-positive (ER+) breast cancer. We also discuss clinical implications and opportunities exploiting IFN signaling to treat advanced ER+ breast cancer.

Flow Cytometry Analysis to Detect Lapatinib-Induced Modulation of Constitutive and IFN-γ-Induced HLA Class I Expression in HER2-Positive Breast Cancer Cells

Drug-induced modulation of HLA molecules on cancer cell lines can easily be detected using flow cytometry and HLA-specific antibodies to ascertain the number of positive cells and their expression levels. Loss or downregulation of HLA-I molecules on cancer cells, a well-documented immune escape mechanism, may occur via activation and integration of numerous signalling pathways that are operative in cancer. Whereas IFN-γ, produced during an adaptive anti-tumor immune response upregulates HLA expression, activation of the human epidermal growth factor receptor 2 (HER2) pathway and its downstream signalling pathways are reported to decrease HLA-I. Here we describe the flow cytometry procedure used to determine whether lapatinib, known to negate HER2 signalling, increased HLA-I expression on HER2+ cell lines, in the presence and absence of IFN-γ. Contrary to our prediction, the flow cytometry data clearly show lapatinib-mediated downregulation of both constitutive and IFN-γ-induced HLA class I expression. These results, for which we do not yet have an explanation, may have important implications for our understanding of lapatinib resistance in metastatic HER2+ cancer.

Western Blot Analysis of Lapatinib-Mediated Inhibition of the Epidermal Growth Factor Receptor 2 (HER2) Pathway in Breast Cancer Cells

Western blotting is an excellent technique to investigate aberrations and/or therapy-induced changes in signaling proteins in cancer. Using an in vitro system, we prepared whole cell lysates from HER2-overexpressing breast cancer cell lines, treated or not with the tyrosine kinase inhibitor, lapatinib, in the presence and absence of IFN-γ. Here we describe the protocol whereby proteins in the lysates were separated by SDS-PAGE, electrophoretically transferred to nitrocellulose membranes followed by an enzyme-linked immunoassay and chemiluminescence to reveal the relevant phosphorylated and dephosphorylated proteins. Herein, Western blot analysis confirmed lapatinib dephosphorylated HER2 and downstream signaling proteins and IFN-γ induced phosphorylation of STAT1.

Distribution Characteristics and Prognostic Value of Immune Infiltration in Oligometastatic Breast Cancer

BACKGROUND

To assess the distribution characteristics and the prognostic value of immune infiltration in female oligometastatic breast cancer patients.

METHODS

We retrospectively analyzed the clinicopathological data of oligometastatic breast cancer (OMBC) patients diagnosed between June 2000 and January 2020. Immune markers were quantified by immunohistochemistry on FFPE tissues in paired normal breast tissues, primary breast cancers and oligometastatic lesions. Survival analyses were performed using the Kaplan-Meier curves and Cox-proportional hazards model.

RESULTS

A total of 95 female OMBC patients visited Sun Yat-sen University Cancer Center between June 2000 and January 2020, and 33 of them had matched normal breast tissues, primary cancers and oligometastatic lesions and were reviewed in immune infiltration analysis. CD8 of primary tumors had a higher expression than that in matched normal tissues. The expressions of CD8 and FOXP3 were higher in the primary sites than that in the oligometastatic lesions. CD3, CD4 and CD8 were significantly lower in the intratumoral regions than that in the peritumoral regions both in primary and oligometastatic lesions. Notably, the high percentage of CD3 in the intratumoral oligometastatic lesions predicted the longer PFS and OS, and higher CD4 in the same lesions also predicted a better OS. There was obviously positive correlation between CD4/CD3 and Ki-67 in primary cancers and negative correlation between CD4/CD3 and ER in oligometastatic sites.

CONCLUSION

We explored immune distribution and evolution in time and space in OMBC to provide new understandings for biological behaviors of this disease and further divided patients in different prognosis.

Impact of Epithelial-Mesenchymal Transition on the Immune Landscape in Breast Cancer

The impact of epithelial-mesenchymal transition (EMT) signature on the immune infiltrate present in the breast cancer tumor microenvironment (TME) is still poorly understood. Since there is mounting interest in the use of immunotherapy for the treatment of subsets of breast cancer patients, it is of major importance to understand the fundamental tumor characteristics which dictate the inter-tumor heterogeneity in immune landscapes. We aimed to assess the impact of EMT-related markers on the nature and magnitude of the inflammatory infiltrate present in breast cancer TME and their association with the clinicopathological parameters. Tissue microarrays were constructed from 144 formalin-fixed paraffin-embedded invasive breast cancer tumor samples. The protein expression patterns of Snail, Twist, ZEB1, N-cadherin, Vimentin, GRHL2, E-cadherin, and EpCAM were examined by immunohistochemistry (IHC). The inflammatory infiltrate in the TME was assessed semi-quantitatively on hematoxylin and eosin (H&E)-stained whole sections and was characterized using IHC. The inflammatory infiltrate was more intense in poorly differentiated carcinomas and triple-negative carcinomas in which the expression of E-cadherin and GRHL2 was reduced, while EpCAM was overexpressed. Most EMT-related markers correlated with plasma cell infiltration of the TME. Taken together, our findings reveal that the EMT signature might impact the immune response in the TME.

Molecular correlates of response to eribulin and pembrolizumab in hormone receptor-positive metastatic breast cancer

Immune checkpoint inhibitors (ICIs) have minimal therapeutic effect in hormone receptor-positive (HR+ ) breast cancer. We present final overall survival (OS) results (n = 88) from a randomized phase 2 trial of eribulin ± pembrolizumab for patients with metastatic HR+ breast cancer, computationally dissect genomic and/or transcriptomic data from pre-treatment tumors (n = 52) for molecular associations with efficacy, and identify cytokine changes differentiating response and ICI-related toxicity (n = 58). Despite no improvement in OS with combination therapy (hazard ratio 0.95, 95% CI 0.59-1.55, p = 0.84), immune infiltration and antigen presentation distinguished responding tumors, while tumor heterogeneity and estrogen signaling independently associated with resistance. Moreover, patients with ICI-related toxicity had lower levels of immunoregulatory cytokines. Broadly, we establish a framework for ICI response in HR+ breast cancer that warrants diagnostic and therapeutic validation. ClinicalTrials.gov Registration: NCT03051659.

Prognostic value of cytokines in breast cancer: Correlation with positive hormonal status and obesity

Background

The relation of interleukin 6 (IL6) and molecular subtypes as well as body mass index is not well settled. Little is known about interferon gamma (IFγ) and prognosis of breast cancer.

Patient and methods

Serum level of IL6 and IFγ was assessed by enzyme-linked immunosorbent assay (ELISA) and correlated with the TNM staging, molecular subtypes, and body mass index.

Results

Among 78 patients, the median age was 54 years. The majority of the cases were T2 (62.8%), N1 (38.5%), and M0 (89.74%) with stage II being the most common (47.4%). Most females were estrogen receptor (97.9%) and progesterone receptor positive (96.9%) with high Ki67 ≥ 20 (61.5%). Her2 neu positive presented 16.7%. Luminal A and luminal B presented 29.5% and 53.8%, respectively. Obese patients presented by far the majority (82.1%).

The median level of IL6 and IFγ was 56.20 ± 28.715 and 76.37 ± 41.54, respectively. IL6 was significantly correlated with tumor size (P = 0.001), nodal involvement (P = >0.0001), the presence of metastasis (P = 0.008), and the stage (P = >0.0001). High level of IL6 was associated with positive estrogen receptor, Her2 neu positive, luminal A, and being obese (P = 0.09, 0.07, 0.06, and 0.05, respectively).

High IFγ was only associated with lower nodal burden being significantly higher in N1 than in N3 (118.15 ± 31.07 vs 76.37 ± 44.46, P = 0.01) and early stage (P = 0.02).

Conclusion

IL6 level was correlated to the initial staging, hormonal status, being Her2 positive, and obesity. The IFγ level was inversely correlated IL6 regarding the nodal status (P = 0.05).

Distinct Molecular Mechanisms of Altered HLA Class II Expression in Malignant Melanoma

BACKGROUND

The human leukocyte antigen (HLA) class II molecules are constitutively expressed in some melanoma, but the underlying molecular mechanisms have not yet been characterized.

METHODS

The expression of HLA class II antigen processing machinery (APM) components was determined in melanoma samples by qPCR, Western blot, flow cytometry and immunohistochemistry. Immunohistochemical and TCGA datasets were used for correlation of HLA class II expression to tumor grading, T-cell infiltration and patients' survival.

RESULTS

The heterogeneous HLA class II expression in melanoma samples allowed us to characterize four distinct phenotypes. Phenotype I totally lacks constitutive HLA class II surface expression, which is inducible by interferon-gamma (IFN-γ); phenotype II expresses low basal surface HLA class II that is further upregulated by IFN-γ; phenotype III lacks constitutive and IFN-γ controlled HLA class II expression, but could be induced by epigenetic drugs; and in phenotype IV, lack of HLA class II expression is not recovered by any drug tested. High levels of HLA class II APM component expression were associated with an increased intra-tumoral CD4+ T-cell density and increased patients' survival.

CONCLUSIONS

The heterogeneous basal expression of HLA class II antigens and/or APM components in melanoma cells is caused by distinct molecular mechanisms and has clinical relevance.

Breast cancer and the renin-angiotensin system (RAS): Therapeutic approaches and related metabolic diseases

The Renin-Angiotensin System (RAS) is classically recognized for regulating blood pressure and fluid balance. Recently, this role has extended to other areas including inflammation, obesity, diabetes, as well as breast cancer. RAS components are expressed in normal and cancerous breast tissues, and downregulation of RAS inhibits metastasis, proliferation, angiogenesis, and desmoplasia in the tumor microenvironment. Therefore, RAS inhibitors (Angiotensin receptor blockers, ARBs, or angiotensin converting enzyme inhibitors, ACE-I) may be beneficial as preventive adjuvant therapies to thwart breast cancer development and improve outcomes, respectively. Given the beneficial effects of RAS inhibitors in metabolic diseases, which often co-exist in breast cancer patients, combining RAS inhibitors with other breast cancer therapies may enhance the effectiveness of current treatments. This review scrutinizes above associations, to advance our understanding of the role of RAS in breast cancer and its potential for repurposing of RAS inhibitors to improve the therapeutic approach for breast cancer patients.

Immunotherapy for Breast Cancer Treatment

Breast cancer, as a heterogeneous disease, includes a wide range of pathological and clinical behaviors. Current treatment protocols, including radiotherapy, chemotherapy, and hormone replacement therapy, are mainly associated with poor response and high rate of recurrence. Therefore, more efforts are needed to develop alternative therapies for this type of cancer. Immunotherapy, as a novel strategy in cancer treatment, has a potential in treating breast cancer patients. Although breast cancer has long been considered problematic to treat with immunotherapy, as it is immunologically "cold," numerous newer preclinical and clinical reports now recommend that immunotherapy has the capability to treat breast cancer patients. In this review, we highlight the different immunotherapy strategies in breast cancer treatment.

Immunotherapy for Breast Cancer Treatment

Breast cancer, as a heterogeneous disease, includes a wide range of pathological and clinical behaviors. Current treatment protocols, including radiotherapy, chemotherapy, and hormone replacement therapy, are mainly associated with poor response and high rate of recurrence. Therefore, more efforts are needed to develop alternative therapies for this type of cancer. Immunotherapy, as a novel strategy in cancer treatment, has a potential in treating breast cancer patients. Although breast cancer has long been considered problematic to treat with immunotherapy, as it is immunologically "cold," numerous newer preclinical and clinical reports now recommend that immunotherapy has the capability to treat breast cancer patients. In this review, we highlight the different immunotherapy strategies in breast cancer treatment.

Lights and Shadows in Immuno-Oncology Drug Development

The rapidly evolving landscape of immuno-oncology (IO) is redefining the treatment of a number of cancer types. IO treatments are becoming increasingly complex, with different types of drugs emerging beyond checkpoint inhibitors. However, many of the new drugs either do not progress from phase I-II clinical trials or even fail in late-phase trials. We have identified at least five areas in the development of promising IO treatments that should be redefined for more efficient designs and accelerated approvals. Here we review those critical aspects of IO drug development that could be optimized for more successful outcome rates in all cancer types. It is important to focus our efforts on the mechanisms of action, types of response and adverse events of these novel agents. The use of appropriate clinical trial designs with robust biomarkers of response and surrogate endpoints will undoubtedly facilitate the development and subsequent approval of these drugs. Further research is also needed to establish biomarker-driven strategies to select which patients may benefit from immunotherapy and identify potential mechanisms of resistance.

Inhibition of BRAF Sensitizes Thyroid Carcinoma to Immunotherapy by Enhancing tsMHCII-mediated Immune Recognition

CONTEXT

Multiple mechanisms play roles in restricting the ability of T-cells to recognize and eliminate tumor cells.

OBJECTIVE

To identify immune escape mechanisms involved in papillary thyroid carcinoma (PTC) to optimize immunotherapy.

SETTING AND DESIGN

iTRAQ analysis was conducted to identify proteins differentially expressed in PTC samples with or without BRAFV600E mutation. Molecular mechanisms regulating tumor cell evasion were investigated by in vitro modulations of BRAF/MAPK and related pathways. The pathological significance of identified tumor-specific major histocompatibility complex class II (tsMHCII) molecules in mediating tumor cell immune escape and targeted immune therapy was further evaluated in a transgenic mouse model of spontaneous thyroid cancer.

RESULTS

Proteomic analysis showed that tsMHCII level was significantly lower in BRAFV600E-associated PTCs and negatively correlated with BRAF mutation status. Constitutive activation of BRAF decreased tsMHCII surface expression on tumor cells, which inhibited activation of CD4+ T-cells and led to immune escape. Pathway analysis indicated that the transforming growth factor (TGF)-β1/SMAD3-mediated repression of tsMHCII, which could be reversed by BRAF inhibition (BRAFi). Targeting this pathway with a combined therapy of BRAF inhibitor PLX4032 and anti-PD-1 antibody efficiently blocked tumor growth by increasing CD4+ T-cell infiltration in a transgenic PTC mouse model.

CONCLUSIONS

Our results suggest that BRAFV600E mutation in PTC impairs the expression of tsMHCII through the TGF-β1/SMAD3 pathway to enhance immune escape. Combined treatment with PLX4032 and anti-PD-1 antibody promotes recognition and elimination of PTC by the immune system in a pre-clinical mouse model, and therefore offers an effective therapeutic strategy for patients with advanced PTC.

Methylome Variation Predicts Exemestane Resistance in Advanced ER+ Breast Cancer

Background:

More than 30% of estrogen receptor-positive breast cancers are resistant to primary hormone therapy, and about 40% that initially respond to hormone therapy eventually acquire resistance. Although the mechanisms of hormone therapy resistance remain unclear, aberrant DNA methylation has been implicated in oncogenesis and drug resistance.

Purpose:

We investigated the relationship between methylome variations in circulating tumor DNA and exemestane resistance, to track hormone therapy efficacy.

Methods:

We prospectively recruited 16 patients who were receiving first-line therapy in our center. All patients received exemestane-based hormone therapy after enrollment. We collected blood samples at baseline, first follow-up (after 2 therapeutic cycles) and at detection of disease progression. Disease that progressed within 6 months under exemestane treatment was considered exemestane resistance but was considered relatively exemestane-sensitive otherwise. We obtained circulating tumor DNA-derived methylomes using the whole-genome bisulfide sequencing method. Methylation calling was done by BISMARK software; differentially methylated regions for exemestane resistance were calculated afterward.

Results:

Median follow-up for the 16 patients was 19.0 months. We found 7 exemestane resistance-related differentially methylated regions, located in different chromosomes, with both significantly different methylation density and methylation ratio. Baseline methylation density and methylation ratio of chromosome 6 [32400000-32599999] were both high in exemestane resistance. High baseline methylation ratios of chromosome 3 [67800000-67999999] (P = .013), chromosome 3 [140200000-140399999] (P = .037), and chromosome 12 [101200000-101399999] (P = .026) could also predict exemestane resistance. During exemestane treatment, synchronized changes in methylation density and methylation ratio in chromosome 6 [32400000-32599999] could accurately stratify patients in terms of progression-free survival (P = .000033). Cutoff values of methylation density and methylation ratio for chromosome 6 [149600000-149799999] were 0.066 and 0.076, respectively.

Conclusion:

Methylation change in chromosome 6 [149600000-149799999] is an ideal predictor of exemestane resistance with great clinical potential.

Optimizing Radiation Therapy to Boost Systemic Immune Responses in Breast Cancer: A Critical Review for Breast Radiation Oncologists

Immunotherapy using immune checkpoint blockade has revolutionized the treatment of many types of cancer. Radiation therapy (RT)-particularly when delivered at high doses using newer techniques-may be capable of generating systemic antitumor effects when combined with immunotherapy in breast cancer. These systemic effects might be due to the local immune-priming effects of RT resulting in the expansion and circulation of effector immune cells to distant sites. Although this concept merits further exploration, several challenges need to be overcome. One is an understanding of how the heterogeneity of breast cancers may relate to tumor immunogenicity. Another concerns the need to develop knowledge and expertise in delivery, sequencing, and timing of RT with immunotherapy. Clinical trials addressing these issues are under way. We here review and discuss the particular opportunities and issues regarding this topic, including the design of informative clinical and translational studies.

Therapeutic applications of the selective high affinity ligand drug SH7139 extend beyond non-Hodgkin's lymphoma to many other types of solid cancers

SH7139, the first of a series of selective high affinity ligand (SHAL) oncology drug candidates designed to target and bind to the HLA-DR proteins overexpressed by B-cell lymphomas, has demonstrated exceptional efficacy in the treatment of Burkitt lymphoma xenografts in mice and a safety profile that may prove to be unprecedented for an oncology drug. The aim of this study was to determine how frequently the HLA-DRs targeted by SH7139 are expressed by different subtypes of non-Hodgkin’s lymphoma and by other solid cancers that have been reported to express HLA-DR. Binding studies conducted with SH7129, a biotinylated analog of SH7139, reveal that more than half of the biopsy sections obtained from patients with different types of non-Hodgkin’s lymphoma express the HLA-DRs targeted by SH7139. Similar analyses of tumor biopsy tissue obtained from patients diagnosed with eighteen other solid cancers show the majority of these tumors also express the HLA-DRs targeted by SH7139. Cervical, ovarian, colorectal and prostate cancers expressed the most HLA-DR. Only a few esophageal and head and neck tumors bound the diagnostic. Within an individual’s tumor, cell to cell differences in HLA-DR target expression varied by only 2 to 3-fold while the expression levels in tumors obtained from different patients varied as much as 10 to 100-fold. The high frequency with which SH7129 was observed to bind to these cancers suggests that many patients diagnosed with B-cell lymphomas, myelomas, and other non-hematological cancers should be considered potential candidates for new therapies such as SH7139 that target HLA-DR-expressing tumors.

Trifolium pratense L. (red clover) extract and doxorubicin synergistically inhibits proliferation of 4T1 breast cancer in tumor-bearing BALB/c mice through modulation of apoptosis and increase antioxidant and anti-inflammatory related pathways

Therapeutic strategies against triple-negative breast cancer (TNBC) are associated with drug-induced toxicities. The tropical edible red clover (Trifolium pratense L.) is rich in polyphenolic compounds which confer the plant potential anticancer properties. The aim of this study was to investigate the effects of T. pratense and doxorubicin (DOX) on the apoptosis and proliferation of 4T1 tumor cells in an allograft model of tumor-bearing BALB/c mice. Fifty-six female 4T1-tumor bearing- BALB/c mice were randomly divided into 7 groups (n = 8/group) to receive different doses and combinations of DOX and T. pratense extract for 35 days. On the 36th day, serum estradiol (E2), IL-12 and IFN-γ cytokines, and glutathione peroxidase (GPx) activity were measured. Tumor's ferric reducing antioxidant power (FRAP) and the expressions of apoptosis-related genes (p53, Bax, Bcl-2, and caspase-3) were also evaluated. Immunohistochemical staining for Ki-67 and p53 were performed. Our results showed that the co-treatment of DOX and T. pratense (100-400 mg/kg) inhibited the proliferation of 4T1 tumor cells in dose- and time-dependent manners. The co-treatment of DOX and T. pratense (especially at the dose of 400 mg/kg) decreased the serum level of E2 (as a stimulant for breast tumor growth) and increased the serum levels of IL-12 and IFN-γ along with significant increments in serum GPx and tumor FRAP activities. The co-administration of DOX and T. pratense also decreased the expression of Ki-67 proliferation marker and increased the number p53 positive (i.e., apoptotic) cells within tumors. This was accompanied with the upregulation of pro-apoptotic and down-regulation of antiapoptotic genes. The key findings indicated the synergistic effects of DOX and T. pratense against TNBC xenografts.

Tumor-infiltrating lymphocytes (TILs) in ER+/HER2- breast cancer

PURPOSE

The prognostic role of tumor-infiltrating lymphocytes (TILs) in ER+/HER2- breast cancer (BC) is debated. We evaluated the association of TILs and clinico-pathological features with distant disease-free survival (DDFS) in patients with ER+/HER2- BC treated at a single institution.

PATIENTS AND METHODS

A mono-institutional case-cohort series of 987 patients with early ER+/HER2- BC was retrospectively analyzed. TILs were considered both as continuous variable, and dichotomized in low (< 5%) vs high (≥ 5%). The main outcome was DDFS. Median follow-up was 7.5 years (0.1-10). Univariate and multivariable Cox proportional hazards regression with inverse sub-cohort sampling probability weighting were used to evaluate the risk across groups.

RESULTS

Median TIL count was 2% (Q1-Q3 1-4%). Higher TILs were positively associated with number of lymph nodes involved (p = 0.003), tumor grade (p < 0.0001), peritumoral vascular invasion (p = 0.003), higher Ki-67 (p = 0.0001), luminal B subtype (p < 0.0001), and chemotherapy use (p < 0.00019). In multivariable regression analysis, only higher Ki-67 expression retained significant association with TILs. At univariate Cox regression analysis, TIL expression (≥ 5% vs. < 5%) was not associated with DDFS (HR 1.08, 95% CI 0.80-1.46, p = 0.62). In patients treated with adjuvant chemotherapy, high TILs were associated with better DDFS (HR 0.52, 95%CI 0.33-0.83, p = 0.006), particularly in the group with Ki-67 ≥ 20% (HR 0.50, 95%CI 0.29-0.86, p = 0.01).

CONCLUSION

High TILs in ER+/HER2- BC are significantly associated with clinico-pathological features of dismal outcome. TIL prognostic value seems different in patients treated with or without chemotherapy. Our findings suggest that the high-risk subgroup might be more immunogenic, thus deserving the exploration of immunotherapy approaches.

Characterization of HLA-G Regulation and HLA Expression in Breast Cancer and Malignant Melanoma Cell Lines upon IFN-γ Stimulation and Inhibition of DNA Methylation

The potential role of human leukocyte antigen (HLA)-G as a target for new cancer immunotherapy drugs has increased the interest in the analysis of mechanisms by which HLA-G expression is regulated, and how the expression can be manipulated. We characterized HLA expression in breast cancer and malignant melanoma cell lines and investigated the induction of HLA-G expression by two distinct mechanisms: stimulation with interferon (IFN)-γ or inhibition of methylation by treatment with 5-aza-2'-deoxycytidine (5-aza-dC). The effect of IFN-γ and 5-aza-dC on HLA expression was dependent on the cancer cell lines studied. However, in general, surface expression of HLA class Ia was induced on all cell lines. Surface expression of HLA-G was inconclusive but induction of HLA-G mRNA was prevalent upon treatment with 5-aza-dC and a combination of IFN-γ and 5-aza-dC. IFN-γ alone failed to induce HLA-G expression in the HLA-G-negative cell lines. The results support that HLA-G expression is regulated partly by DNA methylation. Furthermore, IFN-γ may play a role in the maintenance of HLA-G expression rather than inducing expression. The study demonstrates the feasibility of manipulating HLA expression and contributes to the exploration of mechanisms that can be potential targets for immunotherapy in breast cancer and malignant melanoma.

A dominant RAD51C pathogenic splicing variant predisposes to breast and ovarian cancer in the Newfoundland population due to founder effect

BACKGROUND

RAD51C is important in DNA repair and individuals with pathogenic RAD51C variants have increased risk of hereditary breast and ovarian cancer syndrome (HBOC), an autosomal dominant genetic predisposition to early onset breast and/or ovarian cancer.

METHODS

Five female HBOC probands sequenced negative for moderate- and high-risk genes but shared a recurrent variant of uncertain significance in RAD51C (NM_058216.3: c.571 + 4A > G). Participant recruitment was followed by haplotype and case/control analyses, RNA splicing analysis, gene and protein expression assays, and Sanger sequencing of tumors.

RESULTS

The RAD51C c.571 + 4A > G variant segregates with HBOC, with heterozygotes sharing a 5.07 Mbp haplotype. RAD51C c.571 + 4A > G is increased ~52-fold in the Newfoundland population compared with the general Caucasian population and positive population controls share disease-associated alleles, providing evidence of a founder effect. Splicing analysis confirmed in silico predictions that RAD51C c.571 + 4A > G causes exon 3 skipping, creating an immediate premature termination codon. Gene and protein expression were significantly reduced in a RAD51C c.571 + 4G > A heterozygote compared with a wild-type relative. Sanger sequencing of tumors from two probands indicates loss-of-heterozygosity, suggesting loss of function.

CONCLUSION

The RAD51C c.571 + 4A > G variant affects mRNA splicing and should be re-classified as pathogenic according to American College of Medical Genetics and Genomics guidelines.

Immunotherapy: A Challenge of Breast Cancer Treatment

Breast cancer is the most commonly diagnosed cancer in women and is a leading cause of cancer death in women worldwide. Despite the significant benefit of the use of conventional chemotherapy and monoclonal antibodies in the prognosis of breast cancer patients and although the recent approval of the anti-PD-L1 antibody atezolizumab in combination with chemotherapy has been a milestone for the treatment of patients with metastatic triple-negative breast cancer, immunologic treatment of breast tumors remains a great challenge. In this review, we summarize current breast cancer classification and standard of care, the main obstacles that hinder the success of immunotherapies in breast cancer patients, as well as different approaches that could be useful to enhance the response of breast tumors to immunotherapies.

Signaling Complexity Measured by Shannon Entropy and Its Application in Personalized Medicine

Traditional approaches to cancer therapy seek common molecular targets in tumors from different patients. However, molecular profiles differ between patients, and most tumors exhibit inherent heterogeneity. Hence, imprecise targeting commonly results in side effects, reduced efficacy, and drug resistance. By contrast, personalized medicine aims to establish a molecular diagnosis specific to each patient, which is currently feasible due to the progress achieved with high-throughput technologies. In this report, we explored data from human RNA-seq and protein–protein interaction (PPI) networks using bioinformatics to investigate the relationship between tumor entropy and aggressiveness. To compare PPI subnetworks of different sizes, we calculated the Shannon entropy associated with vertex connections of differentially expressed genes comparing tumor samples with their paired control tissues. We found that the inhibition of up-regulated connectivity hubs led to a higher reduction of subnetwork entropy compared to that obtained with the inhibition of targets selected at random. Furthermore, these hubs were described to be participating in tumor processes. We also found a significant negative correlation between subnetwork entropies of tumors and the respective 5-year survival rates of the corresponding cancer types. This correlation was also observed considering patients with lung squamous cell carcinoma (LUSC) and lung adenocarcinoma (LUAD) based on the clinical data from The Cancer Genome Atlas database (TCGA). Thus, network entropy increases in parallel with tumor aggressiveness but does not correlate with PPI subnetwork size. This correlation is consistent with previous reports and allowed us to assess the number of hubs to be inhibited for therapy to be effective, in the context of precision medicine, by reference to the 100% patient survival rate 5 years after diagnosis. Large standard deviations of subnetwork entropies and variations in target numbers per patient among tumor types characterize tumor heterogeneity.

Mesangial Cells Exhibit Features of Antigen-Presenting Cells and Activate CD4+ T Cell Responses

Background

Mesangial cells play a prominent role in the development of inflammatory diseases and autoimmune disorders of the kidney. Mesangial cells perform the essential functions of helping to ensure that the glomerular structure is stable and regulating capillary flow, and activated mesangial cells acquire proinflammatory activities. We investigated whether activated mesangial cells display immune properties and control the development of T cell immunity.

Methods

Flow cytometry analysis was used to study the expression of antigen-presenting cell surface markers and costimulatory molecules in mesangial cells. CD4+ T cell activation induced by mesangial cells was detected in terms of T cell proliferation and cytokine production.

Results

IFN-γ-treated mesangial cells express membrane proteins involved in antigen presentation and T cell activation, including MHC-II, ICAM-1, CD40, and CD80. This finding suggests that activated mesangial cells can take up and present antigenic peptides to initiate CD4+ T cell responses and thus act as nonprofessional antigen-presenting cells. Polarization of naïve CD4+ T cells (Th0 cells) towards the Th1 phenotype was induced by coculture with activated mesangial cells, and the resulting Th1 cells showed increased mRNA and protein expression of inflammation-associated genes.

Conclusion

Mesangial cells can present antigen and modulate CD4+ T lymphocyte proliferation and differentiation. Interactions between mesangial cells and T cells are essential for sustaining the inflammatory response in a variety of glomerulonephritides. Therefore, mesangial cells might participate in immune function in the kidney.

Biological Consequences of MHC-II Expression by Tumor Cells in Cancer

Immunotherapy has emerged as a key pillar of cancer treatment. To build upon the recent successes of immunotherapy, intense research efforts are aimed at a molecular understanding of antitumor immune responses, identification of biomarkers of immunotherapy response and resistance, and novel strategies to circumvent resistance. These studies are revealing new insight into the intricacies of tumor cell recognition by the immune system, in large part through MHCs. Although tumor cells widely express MHC-I, a subset of tumors originating from a variety of tissues also express MHC-II, an antigen-presenting complex traditionally associated with professional antigen-presenting cells. MHC-II is critical for antigen presentation to CD4+ T lymphocytes, whose role in antitumor immunity is becoming increasingly appreciated. Accumulating evidence demonstrates that tumor-specific MHC-II associates with favorable outcomes in patients with cancer, including those treated with immunotherapies, and with tumor rejection in murine models. Herein, we will review current research regarding tumor-enriched MHC-II expression and regulation in a range of human tumors and murine models, and the possible therapeutic applications of tumor-specific MHC-II.

Interplay between interferon-stimulated gene 15/ISGylation and interferon gamma signaling in breast cancer cells

Interferon-stimulated gene 15 (ISG15) is a ubiquitin-like protein that conjugates to its target proteins to modify them through ISGylation, but the relevance of ISG15 expression and its effects have been not completely defined. Herein, we examined the interplay between ISG15/ISGylation and the interferon-gamma (IFN-γ) signaling pathway in mammary tumors and compared it with that in normal mammary tissues. Our results indicated that mammary tumors had higher levels of ISG15 mRNA and ISG15 protein than the adjacent normal mammary tissue. Furthermore, the expression of IFN-γ signaling components was altered in breast cancer. Interestingly, IFN-γ treatment induced morphological changes in MCF-7 and MDA-MB-231 breast cancer cell lines due to cytoskeletal reorganization. This cellular process seems to be related to the increase in ISGylation of cytoplasmic IQ Motif Containing GTPase Activating Protein 1 (IQGAP1). Interactome analysis also indicated that IFN-γ signaling and the ISGylation system are associated with several proteins implicated in cytoskeletal remodeling, including IQGAP1. Thus, ISG15 may present a potential biomarker for breast cancer, and IFN-γ signaling and protein ISGylation may participate in the regulation of the cytoskeleton in breast cancer cells.

Assessment of expression of interferon γ (IFN-G) gene and its antisense (IFNG-AS1) in breast cancer

BACKGROUND

The role of long non-coding RNAs has been extensively appreciated in the contexts of cancer. Interferon γ-antisense RNA1 (IFNG-AS1) is an lncRNA located near to IFN-γ-encoding (IFNG) gene and regulates expression of IFNG in Th1 cells.

METHODS

In the present study, we evaluated expression of IFNG and IFNG-AS1 in 108 breast samples including tumoral tissues and their adjacent non-cancerous tissues (ANCTs) using real-time PCR. IFNG-AS1 was significantly upregulated in tumoral tissues compared with ANCTs (expression ratio = 2.23, P = 0.03).

RESULTS

Although the expression of IFNG was higher in tumoral tissues compared with ANCTs (relative expression = 1.89), it did not reach the level of significance (P = 0.07). IFNG expression was significantly higher in HER2-negative tumoral tissues compared with HER2-positive ones (P = 0.01) and in grade 1 samples compared with grade 2 ones (P = 0.03). No other significant difference was found in expressions of genes between other groups.

CONCLUSION

Significant strong correlations were detected between expression of IFNG and IFNG-AS1 in both tumoral tissues and ANCTs. The present study provides evidences for participation of IFNG and IFNG-AS1 in the pathogenesis of breast cancer and warrants future studies to elaborate the underlying mechanism.

Evaluation of the prognostic value of CD3, CD8, and FOXP3 mRNA expression in early-stage breast cancer patients treated with anthracycline-based adjuvant chemotherapy

BACKGROUND

Tumor-infiltrating lymphocytes (TILs) have been shown to be of prognostic value in several cancer types. In early breast cancer, TILs have a prognostic utility, as well, especially in HER2-positive and triple-negative breast cancer. TILs presence is broadly associated with improved survival; however, there is controversy regarding TILs subpopulations.

PATIENTS AND METHODS

Early-stage breast cancer patients treated with anthracycline-based chemotherapy within two randomized trials were included in the study. We evaluated, by qRT-PCR, 826 tumor tissue samples for mRNA expression of CD3, CD8, and FOXP3 for potential prognostic significance in terms of disease-free survival (DFS) and overall survival (OS).

RESULTS

After a median follow-up of 133.0 months, 255 patients (30.9%) had died and 314 (38.0%) had disease progression. In the univariate analysis, high CD3 and CD8 mRNA expression was found to be of favorable prognostic value for DFS (P = 0.007 and P = 0.016, respectively). In multivariate analyses, the association of high CD8 mRNA expression with increased DFS was retained (HR = 0.77, 95% CI 0.60-0.998, Wald's P = 0.048), whereas that of high CD3 mRNA expression was of marginal statistical significance (HR = 0.77, 95% CI 0.59-1.01, P = 0.059). Moreover, a significant interaction was observed between HER2 status and CD3 mRNA expression with respect to DFS (interaction P = 0.032). In the HER2-positive subgroup, the hazard ratio associated with high CD3 mRNA expression was of greater magnitude (HR = 0.48, 95% CI 0.30-0.76, P = 0.002) compared with the hazard ratio presented above, for the entire cohort. No significant findings were observed for FOXP3 in terms of DFS, while none of the studied markers were of prognostic value for OS.

CONCLUSIONS

High CD3 and CD8 mRNA expression in early-stage breast cancer patients is of prognostic value for decreased risk of relapse and, in the future, could potentially be of importance in deciding the most appropriate therapeutic strategy in light of the recent immune-related treatment developments.

Oncolytic Reovirus and Immune Checkpoint Inhibition as a Novel Immunotherapeutic Strategy for Breast Cancer

As the current efficacy of oncolytic viruses (OVs) as monotherapy is limited, exploration of OVs as part of a broader immunotherapeutic treatment strategy for cancer is necessary. Here, we investigated the ability for immune checkpoint blockade to enhance the efficacy of oncolytic reovirus (RV) for the treatment of breast cancer (BrCa). In vitro, oncolysis and cytokine production were assessed in human and murine BrCa cell lines following RV exposure. Furthermore, RV-induced upregulation of tumor cell PD-L1 was evaluated. In vivo, the immunocompetent, syngeneic EMT6 murine model of BrCa was employed to determine therapeutic and tumor-specific immune responses following treatment with RV, anti-PD-1 antibodies or in combination. RV-mediated oncolysis and cytokine production were observed following BrCa cell infection and RV upregulated tumor cell expression of PD-L1. In vivo, RV monotherapy significantly reduced disease burden and enhanced survival in treated mice, and was further enhanced by PD-1 blockade. RV therapy increased the number of intratumoral regulatory T cells, which was reversed by the addition of PD-1 blockade. Finally, dual treatment led to the generation of a systemic adaptive anti-tumor immune response evidenced by an increase in tumor-specific IFN-γ producing CD8⁺ T cells, and immunity from tumor re-challenge. The combination of PD-1 blockade and RV appears to be an efficacious immunotherapeutic strategy for the treatment of BrCa, and warrants further investigation in early-phase clinical trials.

Differential expression of major histocompatibility complex class I in subtypes of breast cancer is associated with estrogen receptor and interferon signaling

Tumor-infiltrating lymphocytes (TILs) in triple-negative breast cancer (TNBC) have a strong prognostic and predictive significance. However, the mechanism of TIL influx in TNBC is unclear. Expression of major histocompatibility complex class I (MHC I) on the tumor cell is essential for the effective killing of tumor by cytotoxic TILs. In our current study, human leukocyte antigen (HLA) expression was inversely correlated with estrogen receptor (ER) expression in normal and cancerous breast tissue and positively correlated with TILs in breast cancer. The ER score was inversely correlated with TILs in breast cancer. HLA-A and CD8B gene expression was negatively correlated with ESR1 and positively correlated with interferon-associated gene expression in The Cancer Genome Atlas (TCGA) data. Negative correlation between ESR1 and HLA and positive correlation between interferon-associated and HLA gene expression were also confirmed in Cancer Cell Line Encyclopedia (CCLE) data. Taken together, our data suggest that a lower expression of HLA in luminal-type tumors might be associated with low level of TILs in those tumors. Further investigation of the mechanism of higher HLA expression and TIL influx in TNBC may help to boost the host immune response.

Promoter Methylation Modulates Indoleamine 2,3-Dioxygenase 1 Induction by Activated T Cells in Human Breast Cancers

Triple-negative breast cancer (TNBC) cells are modulated in reaction to tumor-infiltrating lymphocytes. However, their specific responses to this immune pressure are unknown. In order to address this question, we first used mRNA sequencing to compare the immunophenotype of the TNBC cell line MDA-MB-231 and the luminal breast cancer cell line MCF7 after both were cocultured with activated human T cells. Despite similarities in the cytokine-induced immune signatures of the two cell lines, MDA-MD-231 cells were able to transcribe more IDO1 than MCF7 cells. The two cell lines had similar upstream JAK/STAT1 signaling and IDO1 mRNA stability. However, using a series of breast cancer cell lines, IFNγ stimulated IDO1 protein expression and enzymatic activity only in ER^-, not ER⁺, cell lines. Treatment with 5-aza-deoxycytidine reversed the suppression of IDO1 expression in MCF7 cells, suggesting that DNA methylation was potentially involved in IDO1 induction. By analyzing several breast cancer datasets, we discovered subtype-specific mRNA and promoter methylation differences in IDO1, with TNBC/basal subtypes exhibiting lower methylation/higher expression and ER⁺/luminal subtypes exhibiting higher methylation/lower expression. We confirmed this trend of IDO1 methylation by bisulfite pyrosequencing breast cancer cell lines and an independent cohort of primary breast tumors. Taken together, these findings suggest that IDO1 promoter methylation regulates anti-immune responses in breast cancer subtypes and could be used as a predictive biomarker for IDO1 inhibitor-based immunotherapy. Cancer Immunol Res; 5(4); 330-44. ©2017 AACR.

Clinical significance of tumor-infiltrating lymphocytes in breast cancer

Tumor infiltrating lymphocytes (TIL) play an essential role in mediating response to chemotherapy and improving clinical outcomes in all subtypes of breast cancer. Triple negative breast cancers (TN) are most likely to have tumors with >50 % lymphocytic infiltrate, termed lymphocyte predominant breast cancer, and derive the greatest survival benefit from each 10 % increase in TIL. The majority of HER2+ breast cancers have similar level of immune infiltrate as TN breast cancer yet the presence of TILs has not shown the same survival benefit. For HER2+ breast cancers, type 1 T-cells, either increased TBET+ tumor infiltration or increased type 1 HER2-specific CD4+ T-cells in the peripheral blood, are associated with better outcomes. Hormone receptor positive HER2 negative tumors tend to have the least immune infiltrate yet are the only breast cancer subtype to show worse prognosis with increased FOXP3 regulatory T-cell infiltrate. Notably, all breast cancer subtypes have tumors with low, intermediate, or high TIL infiltrate. Tumors with high TILs may also have increased PD-L1 expression which might be the reason that TN breast cancer seems to demonstrate the most robust clinical response to immune checkpoint inhibitor therapy but further investigation is needed. Tumors with intermediate or low levels of pre-treatment immune infiltrate, on the other hand, may benefit from an intervention that may increase TIL, particularly type 1 T-cells. Examples of these interventions include specific types of cytotoxic chemotherapy, radiation, or vaccine therapy. Therefore, the systematic evaluation of TIL and specific populations of TIL may be able to both guide prognosis and the appropriate sequencing of therapies in breast cancer.

Portraying breast cancers with long noncoding RNAs

Evidence is emerging that long noncoding RNAs (lncRNAs) may play a role in cancer development, but this role is not yet clear. We performed a genome-wide transcriptional survey to explore the lncRNA landscape across 995 breast tissue samples. We identified 215 lncRNAs whose genes are aberrantly expressed in breast tumors, as compared to normal samples. Unsupervised hierarchical clustering of breast tumors on the basis of their lncRNAs revealed four breast cancer subgroups that correlate tightly with PAM50-defined mRNA-based subtypes. Using multivariate analysis, we identified no less than 210 lncRNAs prognostic of clinical outcome. By analyzing the coexpression of lncRNA genes and protein-coding genes, we inferred potential functions of the 215 dysregulated lncRNAs. We then associated subtype-specific lncRNAs with key molecular processes involved in cancer. A correlation was observed, on the one hand, between luminal A-specific lncRNAs and the activation of phosphatidylinositol 3-kinase, fibroblast growth factor, and transforming growth factor-β pathways and, on the other hand, between basal-like-specific lncRNAs and the activation of epidermal growth factor receptor (EGFR)-dependent pathways and of the epithelial-to-mesenchymal transition. Finally, we showed that a specific lncRNA, which we called CYTOR, plays a role in breast cancer. We confirmed its predicted functions, showing that it regulates genes involved in the EGFR/mammalian target of rapamycin pathway and is required for cell proliferation, cell migration, and cytoskeleton organization. Overall, our work provides the most comprehensive analyses for lncRNA in breast cancers. Our findings suggest a wide range of biological functions associated with lncRNAs in breast cancer and provide a foundation for functional investigations that could lead to new therapeutic approaches.

Repurposing Sunitinib with Oncolytic Reovirus as a Novel Immunotherapeutic Strategy for Renal Cell Carcinoma

PURPOSE

In addition to their direct cytopathic effects, oncolytic viruses are capable of priming antitumor immune responses. However, strategies to enhance the immunotherapeutic potential of these agents are lacking. Here, we investigated the ability of the multi-tyrosine kinase inhibitor and first-line metastatic renal cell carcinoma (RCC) agent, sunitinib, to augment the antitumor immune response generated by oncolytic reovirus.

EXPERIMENTAL DESIGN

In vitro, oncolysis and chemokine production were assessed in a panel of human and murine RCC cell lines after exposure to reovirus, sunitinib, or their combination. In vivo, the RENCA syngeneic murine model of RCC was employed to determine therapeutic and tumor-specific immune responses after treatment with reovirus (intratumoral), sunitinib, or their combination. Parallel investigations employing the KLN205 syngeneic murine model of lung squamous cell carcinoma (NSCLC) were conducted for further validation.

RESULTS

Reovirus-mediated oncolysis and chemokine production was observed following RCC infection. Reovirus monotherapy reduced tumor burden and was capable of generating a systemic adaptive antitumor immune response evidenced by increased numbers of tumor-specific CD8⁺ IFNγ-producing cells. Coadministration of sunitinib with reovirus further reduced tumor burden resulting in improved survival, decreased accumulation of immune suppressor cells, and the establishment of protective immunity upon tumor rechallenge. Similar results were observed for KLN205 tumor-bearing mice, highlighting the potential broad applicability of this approach.

CONCLUSIONS

The ability to repurpose sunitinib for augmentation of reovirus' immunotherapeutic efficacy positions this novel combination therapy as an attractive strategy ready for clinical testing against a range of histologies, including RCC and NSCLC. Clin Cancer Res; 22(23); 5839-50. ©2016 AACR.

The immune system and hormone-receptor positive breast cancer: Is it really a dead end?

Even if breast cancer has not been traditionally considered an immunogenic tumor, recent data suggest that immunity, and its interaction with tumor cells and tumor microenvironment, might play an important role in this malignancy, in particular in triple negative and HER2+ subtypes. As no consistent data on the potential clinical relevance of tumor infiltrating lymphocytes have been produced in hormone receptor positive (HR+) HER2- breast cancer, the interest in studying immune aspects in this subtype has become less appealing. Nevertheless, some scattered evidence indicates that immunity and inflammation may be implicated in the biology of this subtype as well. In HR+ breast cancer, the interaction between tumor cells and the immune milieu might rely on different mechanisms than in other BC subtypes, involving the modulation of the tumor microenvironment by mutual interplays of endocrine factors, pro-inflammatory status and immune cells. These subtle mechanisms may require more refined methods of evaluation, such as the assessment of tumor infiltrating lymphocytes subpopulations or gene signatures. In this paper we aim to perform a comprehensive review of pre-clinical and clinical data on the interplay between the immune system and breast cancer in the HR+ subtype, to guide further research in the field.