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TIFF file for supplementary figure S3

Purpose: Abnormal activation of the NF-κB pathway induces a more aggressive phenotype of cutaneous melanoma. Understanding the mechanisms involved in melanoma NF-κB activation may identify novel targets for this pathway. KPC1, an E3 ubiquitin ligase, is a regulator of the NF-κB pathway. The objective of this study was to investigate the mechanisms regulating KPC1 expression and its clinical impact in melanoma.Experimental Design: The clinical impact of KPC1 expression and its epigenetic regulation were assessed in large cohorts of clinically well-annotated melanoma tissues (tissue microarrays; n = 137, JWCI cohort; n = 40) and The Cancer Genome Atlas database (TCGA cohort, n = 370). Using melanoma cell lines, we investigated the functional interactions between KPC1 and NF-κB, and the epigenetic regulations of KPC1, including DNA methylation and miRNA expression.Results: We verified that KPC1 suppresses melanoma proliferation by processing NF-κB1 p105 into p50, thereby modulating NF-κB target gene expression. Concordantly, KPC1 expression was downregulated in American Joint Committee on Cancer stage IV melanoma compared with early stages (stage I/II P = 0.013, stage III P = 0.004), and low KPC1 expression was significantly associated with poor overall survival in stage IV melanoma (n = 137; HR 1.810; P = 0.006). Furthermore, our data showed that high miR-155-5p expression, which is controlled by DNA methylation at its promoter region (TCGA; Pearson's r −0.455; P < 0.001), is significantly associated with KPC1 downregulation (JWCI; P = 0.028, TCGA; P = 0.003).Conclusions: This study revealed novel epigenetic regulation of KPC1 associated with NF-κB pathway activation, promoting metastatic melanoma progression. These findings suggest the potential utility of KPC1 and its epigenetic regulation as theranostic targets. Clin Cancer Res; 23(16); 4831–42. ©2017 AACR.

The file contains Supplementary Table S1 and figure legends for Supplementary Figure S1 to S4

GH-secreting PAs starburst plot gene details. The top 50 most significantly differentially expressed genes contained within Figure 5 for GH-secreting PAs as compared to endocrine-inactive PAs. The table has five columns; 1) gene symbol, 2) Entrez ID number, 3) the log fold change value from the RNA-seq differential expression analysis comparing GH-secreting PAs to endocrine-inactive PAs, 4) the change in methylation beta values between GH-secreting PAs and endocrine-inactive PAs, and 5) the genomic feature for the methylation data.

Table of significant SCNAs among PAs. This table highlights the top 10 most significant GISTIC2 calls for all PAs in this study, each PA subtype, and invasive versus non-invasive PAs.

ACTH-secreting PAs starburst plot gene details. The top 50 most significantly differentially expressed genes contained within Figure 5 for ACTH-secreting PAs as compared to endocrine-inactive PAs. The table has five columns; 1) gene symbol, 2) Entrez ID number, 3) the log fold change value from the RNA-seq differential expression analysis comparing ACTH-secreting PAs to endocrine-inactive PAs, 4) the change in methylation beta values between ACTH-secreting PAs and endocrine-inactive PAs, and 5) the genomic feature for the methylation data.

Purpose: Pituitary adenomas are one of the most common benign neoplasms of the central nervous system. Although emerging evidence suggests roles for both genetic and epigenetic factors in tumorigenesis, the degree to which these factors contribute to disease remains poorly understood.Experimental Design: A multiplatform analysis was performed to identify the genomic and epigenomic underpinnings of disease among the three major subtypes of surgically resected pituitary adenomas in 48 patients: growth hormone (GH)–secreting (n = 17), adrenocorticotropic hormone (ACTH)–secreting (n = 13, including 3 silent-ACTH adenomas), and endocrine-inactive (n = 18). Whole-exome sequencing was used to profile the somatic mutational landscape, whole-transcriptome sequencing was used to identify disease-specific patterns of gene expression, and array-based DNA methylation profiling was used to examine genome-wide patterns of DNA methylation.Results: Recurrent single-nucleotide and small indel somatic mutations were infrequent among the three adenoma subtypes. However, somatic copy-number alterations (SCNA) were identified in all three pituitary adenoma subtypes. Methylation analysis revealed adenoma subtype-specific DNA methylation profiles, with GH-secreting adenomas being dominated by hypomethylated sites. Likewise, gene-expression patterns revealed adenoma subtype-specific profiles. Integrating DNA methylation and gene-expression data revealed that hypomethylation of promoter regions are related with increased expression of GH1 and SSTR5 genes in GH-secreting adenomas and POMC gene in ACTH-secreting adenomas. Finally, multispectral IHC staining of immune-related proteins showed abundant expression of PD-L1 among all three adenoma subtypes.Conclusions: Taken together, these data stress the contribution of epigenomic alterations to disease-specific etiology among adenoma subtypes and highlight potential targets for future immunotherapy-based treatments. This article reveals novel insights into the epigenomics underlying pituitary adenomas and highlights how differences in epigenomic states are related to important transcriptome alterations that define adenoma subtypes. Clin Cancer Res; 24(17); 4126–36. ©2018 AACR.

PCA analysis of genome-wide methylation profiles. PCA analysis using all probes in the methylation data set. Points are colored by the percent of the genome altered by SCNAs. The three PA subtypes are indicated by the shape of the points, with GH-secreting PAs represented by dots, ACTH-secreting PAs represented by triangles, and endocrine-inactive PAs represented by squares. Ellipses indicate 95% confidence intervals. Overall, PAs cluster by PA subtype and not by the percent of the genome disrupted by SCNAs.

PCA analysis of genome-wide gene expression profiles. PCA analysis using all genes in the gene expression data set. Points are colored by the percent of the genome altered by SCNAs. The three PA subtypes are indicated by the shape of the points, with GH-secreting PAs represented by dots, ACTH-secreting PAs represented by triangles, and endocrine-inactive PAs represented by squares. Ellipses indicate 95% confidence intervals. Overall, PAs cluster by PA subtype and not by the percent of the genome disrupted by SCNAs.

Table of clinical parameters for each patient sample.

PURPOSE Appendiceal cancer is a rare disease process with complex treatment strategies. The objective of this study was to identify mutation-based genetic subtypes that may differ from the current histological classification, compare the genetic make-up of primaries and metastases, and find novel targetable alterations. METHODS The analyses involved the curation and normalization of gene mutation panels from appendiceal adenocarcinoma and mucinous adenocarcinoma (n = 196) stored in the AACR GENIE Database v6.0. Genes mutated in less than one patient and tumors profiled with incomplete mutation panels were excluded from the study. The optimal number of AC subtypes was established using the Nonnegative Matrix Factorization algorithm. Statistical comparisons of mutation frequencies were performed using Pearson's χ2 test. RESULTS AC patients were stratified into five mutation subtypes, based on a final set of 41 cancer-related genes. AC0 had no mutations. The most frequently mutated genes varied between the subtypes were: AC1: KRAS (91.9%) and GNAS (77.4%); AC2: KRAS (52.5%), APC (32.5%), and GNAS (30%); AC3: KMT2D (38.7%), TP53 (38.7%), KRAS (35.5%), EP300 (22.6%); and AC4: TP53 (97.2%), KRAS (77.8%), and SMAD4 (36.1%). Additionally, AC3 was less likely to be mucinous (22.6% vs. 50.0-74.2%, p

Molecular testing on surgical specimens predicts disease recurrence and benefit of adjuvant chemotherapy in hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2−) early-stage breast cancer (EBC). Testing on core biopsies has become common practice despite limited evidence of concordance between core/surgical samples. In this study, we compared the gene expression of the 21 genes and the recurrence score (RS) between paired core/surgical specimens. Eighty patients with HR+/HER2− EBC were evaluated from two publicly available gene expression datasets (GSE73235, GSE76728) with paired core/surgical specimens without neoadjuvant systemic therapy. The expression of the 21 genes was compared in paired samples. A microarray-based RS was calculated and a value ≥ 26 was defined as high-RS. The concordance rate and kappa statistic were used to evaluate the agreement between the RS of paired samples. Overall, there was no significant difference and a high correlation in the gene expression levels of the 21 genes between paired samples. However, CD68 and RPLP0 in GSE73235, AURKA, BAG1, and TFRC in GSE76728, and MYLBL2 and ACTB in both datasets exhibited weak to moderate correlation (r

The protocadherin proteins are cell adhesion molecules at the crossroad of signaling pathways playing a major role in neuronal development. It is now understood that their role as signaling hubs is not only important for the normal physiology of cells but also for the regulation of hallmarks of cancerogenesis. Importantly, protocadherins form a cluster of genes that are regulated by DNA methylation. We have identified for the first time that PCDHB15 gene is DNA-hypermethylated on its unique exon in the metastatic melanoma-derived cell lines and patients’ metastases compared to primary tumors. This DNA hypermethylation silences the gene, and treatment with the DNA demethylating agent 5-aza-2′-deoxycytidine reinduces its expression. We explored the role of PCDHB15 in melanoma aggressiveness and showed that overexpression impairs invasiveness and aggregation of metastatic melanoma cells in vitro and formation of lung metastasis in vivo. These findings highlight important modifications of the methylation of the PCDHβ genes in melanoma and support a functional role of PCDHB15 silencing in melanoma aggressiveness.

Background Breast cancer survival is improving due to early detection and treatment advances. However, racial/ethnic differences in tumor biology, stage, and mortality remain. The objective of this study was to analyze presumed disparities at a local level. Methods Breast cancer patients at a county hospital and private hospital from 2010 to 2012 were retrospectively reviewed. Demographic, clinical, pathologic, and surgical data were collected. Comparisons were made between hospital cohorts and between racial/ethnic groups from both hospitals combined. Results 754 patients were included (322 from county hospital and 432 from private hospital). All patients were female. The median age was 54 years at county hospital and 60 years at private hospital ( P < .0001). Racial/ethnic minorities comprised 85% of county hospital patients vs. 12% of private hospital patients ( P < .0001). County hospital patients had a higher grade, clinical/pathologic stage, HER2-positive rate, and mastectomy rate. Compared to other racial/ethnic groups, non-Hispanic white women were more likely to have lower grade and ER-positive tumors. Hispanic/Latina women were younger and were more likely to have HER2-positive tumors. Both Hispanic/Latina and non-Hispanic black women presented at higher clinical stages and were more likely to undergo neoadjuvant chemotherapy and mastectomy. Discussion At county hospital compared to private hospital, the proportion of racial/ethnic minorities was higher, and patients presented at younger ages with more aggressive tumors and more advanced disease. The racial/ethnic disparities that were identified locally are largely consistent with those identified in national database studies. These marked differences at hospitals within a diverse city highlight the need for further research into the disparities.

Background: During embryogenesis, lateral symmetry is broken giving rise to Left/Right (L/R) breast tissues with distinct identity. L/R-sided breast tumors exhibit consistently-biased incidence, gene expression, and DNA methylation. We postulate that a differential L/R tumor-microenvironment crosstalk generates different tumorigenesis mechanisms. Methods: We performed in-silico analyses on breast tumors of public datasets, developed xenografted tumors, and conditioned MDA-MB-231 cells with L/R mammary extracts. Results: We found L/R differential DNA methylation involved in embryogenic and neuron-like functions. Focusing on ion-channels, we discovered significant L/R epigenetic and bioelectric differences. Specifically, L-sided cells presented increased methylation of hyperpolarizing ion channel genes and increased Ca2+ concentration and depolarized membrane potential, compared to R-ones. Functional consequences were associated with increased proliferation in left tumors, assessed by KI67 expression and mitotic count. Conclusions: Our findings reveal considerable L/R asymmetry in cancer processes, and suggest specific L/R epigenetic and bioelectric differences as future targets for cancer therapeutic approaches in the breast and many other paired organs.

Simple Summary Triple-negative breast cancer (TNBC) outcomes are improving since the implementation of immunotherapy. However, objective response rates are still limited to a select group of patients. This is partly due to TNBC intrinsic immune evasive mechanisms and the lack of proper tumor microenvironment immune system activation. Dynamic epigenetic modifications contribute to immune surveillance and immune escape in cancer and can be reverted through epigenetic drugs. This review summarizes the epigenetic changes in TNBC cells and their contribution to the cancer cell–immunity cycle. Furthermore, it also describes how epigenetic drugs may provide novel biomarkers for immunotherapy and enhance the immune response. This manuscript lists the current clinical trials using epigenetic drugs alone or combined with either immune checkpoint inhibitors or small molecules. Abstract Triple-negative breast cancer (TNBC) is defined by the absence of estrogen receptor and progesterone receptor and human epidermal growth factor receptor 2 (HER2) overexpression. This malignancy, representing 15–20% of breast cancers, is a clinical challenge due to the lack of targeted treatments, higher intrinsic aggressiveness, and worse outcomes than other breast cancer subtypes. Immune checkpoint inhibitors have shown promising efficacy for early-stage and advanced TNBC, but this seems limited to a subgroup of patients. Understanding the underlying mechanisms that determine immunotherapy efficiency is essential to identifying which TNBC patients will respond to immunotherapy-based treatments and help to develop new therapeutic strategies. Emerging evidence supports that epigenetic alterations, including aberrant chromatin architecture conformation and the modulation of gene regulatory elements, are critical mechanisms for immune escape. These alterations are particularly interesting since they can be reverted through the inhibition of epigenetic regulators. For that reason, several recent studies suggest that the combination of epigenetic drugs and immunotherapeutic agents can boost anticancer immune responses. In this review, we focused on the contribution of epigenetics to the crosstalk between immune and cancer cells, its relevance on immunotherapy response in TNBC, and the potential benefits of combined treatments.

Glioblastoma (GBM) is the most aggressive primary brain tumor, having a poor prognosis and a median overall survival of less than two years. Over the last decade, numerous findings regarding the distinct molecular and genetic profiles of GBM have led to the emergence of several therapeutic approaches. Unfortunately, none of them has proven to be effective against GBM progression and recurrence. Epigenetic mechanisms underlying GBM tumor biology, including histone modifications, DNA methylation, and chromatin architecture, have become an attractive target for novel drug discovery strategies. Alterations on chromatin insulator elements (IEs) might lead to aberrant chromatin remodeling via DNA loop formation, causing oncogene reactivation in several types of cancer, including GBM. Importantly, it is shown that mutations affecting the isocitrate dehydrogenase (IDH) 1 and 2 genes, one of the most frequent genetic alterations in gliomas, lead to genome-wide DNA hypermethylation and the consequent IE dysfunction. The relevance of IEs has also been observed in a small population of cancer stem cells known as glioma stem cells (GSCs), which are thought to participate in GBM tumor initiation and drug resistance. Recent studies revealed that epigenomic alterations, specifically chromatin insulation and DNA loop formation, play a crucial role in establishing and maintaining the GSC transcriptional program. This review focuses on the relevance of IEs in GBM biology and their implementation as a potential theranostic target to stratify GBM patients and develop novel therapeutic approaches. We will also discuss the state-of-the-art emerging technologies using big data analysis and how they will settle the bases on future diagnosis and treatment strategies in GBM patients.

Triple-negative breast cancer (TNBC) is a heterogeneous collection of breast tumors with numerous differences including morphological characteristics, genetic makeup, immune-cell infiltration, and response to systemic therapy. DNA methylation profiling is a robust tool to accurately identify disease-specific subtypes. We aimed to generate an epigenetic subclassification of TNBC tumors (epitypes) with utility for clinical decision-making. Genome-wide DNA methylation profiles from TNBC patients generated in the Cancer Genome Atlas project were used to build machine learning-based epigenetic classifiers. Clinical and demographic variables, as well as gene expression and gene mutation data from the same cohort, were integrated to further refine the TNBC epitypes. This analysis indicated the existence of four TNBC epitypes, named as Epi-CL-A, Epi-CL-B, Epi-CL-C, and Epi-CL-D. Patients with Epi-CL-B tumors showed significantly shorter disease-free survival and overall survival [log rank; P = 0.01; hazard ratio (HR) 3.89, 95% confidence interval (CI) 1.3–11.63 and P = 0.003; HR 5.29, 95% CI 1.55–18.18, respectively]. Significant gene expression and mutation differences among the TNBC epitypes suggested alternative pathway activation that could be used as ancillary therapeutic targets. These epigenetic subtypes showed complementarity with the recently described TNBC transcriptomic subtypes. TNBC epigenetic subtypes exhibit significant clinical and molecular differences. The links between genetic make-up, gene expression programs, and epigenetic subtypes open new avenues in the development of laboratory tests to more efficiently stratify TNBC patients, helping optimize tailored treatment approaches.

Pathological response to neoadjuvant chemotherapy (NAC) is critical in prognosis and selection of systemic treatments for patients with triple-negative breast cancer (TNBC). The aim of this study is to identify gene expression-based markers to predict response to NAC. A survey of 43 publicly available gene expression datasets was performed. We identified a cohort of TNBC patients treated with NAC (n = 708). Gene expression data from different studies were renormalized, and the differences between pretreatment (pre-NAC), on-treatment (post-C1), and surgical (Sx) specimens were evaluated. Euclidean statistical distances were calculated to estimate changes in gene expression patterns induced by NAC. Hierarchical clustering and pathway enrichment analyses were used to characterize relationships between differentially expressed genes and affected gene pathways. Machine learning was employed to refine a gene expression signature with the potential to predict response to NAC. Forty nine genes consistently affected by NAC were involved in enhanced regulation of wound response, chemokine release, cell division, and decreased programmed cell death in residual invasive disease. The statistical distances between pre-NAC and post-C1 significantly predicted pathological complete response [area under the curve (AUC) = 0.75; p = 0.003; 95% confidence interval (CI) 0.58–0.92]. Finally, the expression of CCND1, a cyclin that forms complexes with CDK4/6 to promote the cell cycle, was the most informative feature in pre-NAC biopsies to predict response to NAC. The results of this study reveal significant transcriptomic changes induced by NAC and suggest that chemotherapy-induced gene expression changes observed early in therapy may be good predictors of response to NAC.

Purpose Hotspot blood cell-free DNA (cfDNA) biomarker assays have limited utility in profiling tumor heterogeneity and burden and in capturing regional metastasis with low disease burden in patients with melanoma. We investigated the utility of a sensitive 54–cancer gene digital next-generation sequencing approach targeting blood cfDNA single nucleotide variants (SNVs) and copy number amplification for monitoring disease in patients with melanoma with regional or distant organ metastasis (DOM). Patients and Methods A total of 142 blood samples were evaluated by digital next-generation sequencing across two patient cohorts. Cohort 1 contained 44 patients with stage II, III, or IV disease with matched tumor DNA at the time of surgery or DOM. Cohort 2 consisted of 12 overlapping patients who were longitudinally monitored after complete lymph node dissection to DOM. Results In cohort 1, cfDNA SNVs were detected in 75% of patients. Tumor-cfDNA somatic SNV concordance was 85% at a variant allele fraction of ≥ 0.5%. An SNV load (number of unique SNVs detected) of greater than two SNVs and an SNV burden (total cumulative SNV VAF) of > 0.5% were significantly associated with worse overall survival ( P < .05) in stage IV patients. In cohort 2, 98 longitudinal blood samples along with matched regional and distant metastases from 12 stage III patients were analyzed before complete lymph node dissection and throughout disease progression. cfDNA SNV levels correlated with tumor burden ( P = .019), enabled earlier detection of recurrence compared with radiologic imaging ( P < .01), captured tumor heterogeneity, and identified increasing SNVs levels before recurrence. Conclusion This study demonstrates significant utility for cfDNA profiling in patients with melanoma with regional and/or distant metastasis for earlier detection of recurrence and progression and in capturing tumor evolution and heterogeneity, thus impacting how patients with melanoma are monitored.

Melanoma has the highest propensity to metastasize to the brain compared to other cancers, as brain metastases are found frequently high in patients who have prolonged survival with visceral metastasis. Once disseminated in the brain, melanoma cells communicate with brain resident cells that include astrocytes and microglia. Microglia cells are the resident macrophages of the brain and are the main immunological cells in the CNS involved in neuroinflammation. Data on the interactions between brain metastatic melanoma cells and microglia and on the role of microglia-mediated neuroinflammation in facilitating melanoma brain metastasis are lacking. To elucidate the role of microglia in melanoma brain metastasis progression, we examined the bidirectional interactions between microglia and melanoma cells in the tumor microenvironment. We identified the molecular and functional modifications occurring in brain-metastasizing melanoma cells and microglia cells after the treatment of each cell type with supernatants of the counter cell type. Both cells induced alteration in gene expression programs, cell signaling, and cytokine secretion in the counter cell type. Moreover, melanoma cells exerted significant morphological changes on microglia cells, enhanced proliferation, induced matrix metalloproteinase-2 (MMP-2) activation, and cell migration. Microglia cells induced phenotypic changes in melanoma cells increasing their malignant phenotype: increased melanoma proliferation, MMP-2 activity, cell migration, brain endothelial penetration, and tumor cells ability to grow as spheroids in 3D cultures. Our work provides a novel insight into the bidirectional interactions between melanoma and micoglia cells, suggesting the contribution of microglia to melanoma brain metastasis formation.

Optimal treatment of brain metastases is often hindered by limitations in diagnostic capabilities. To meet this challenge, here we profile DNA methylomes of the three most frequent types of brain metastases: melanoma, breast, and lung cancers (n = 96). Using supervised machine learning and integration of DNA methylomes from normal, primary, and metastatic tumor specimens (n = 1860), we unravel epigenetic signatures specific to each type of metastatic brain tumor and constructed a three-step DNA methylation-based classifier (BrainMETH) that categorizes brain metastases according to the tissue of origin and therapeutically relevant subtypes. BrainMETH predictions are supported by routine histopathologic evaluation. We further characterize and validate the most predictive genomic regions in a large cohort of brain tumors (n = 165) using quantitative-methylation-specific PCR. Our study highlights the importance of brain tumor-defining epigenetic alterations, which can be utilized to further develop DNA methylation profiling as a critical tool in the histomolecular stratification of patients with brain metastases., The treatment of brain metastases is often limited by the ability to diagnose their origins. Here the authors generate DNA methylomes from the three most frequent types of brain metastases, identify epigenetic signatures specific to each type of metastasis and construct a DNA methylation-based classifier (BrainMETH) to advance brain metastasis diagnosis.

Ligand-dependent corepressor (LCOR) mediates normal and malignant breast stem cell differentiation. Cancer stem cells (CSCs) generate phenotypic heterogeneity and drive therapy resistance, yet their role in immunotherapy is poorly understood. Here we show that immune-checkpoint blockade (ICB) therapy selects for LCORlow CSCs with reduced antigen processing/presentation machinery (APM) driving immune escape and ICB resistance in triple-negative breast cancer (TNBC). We unveil an unexpected function of LCOR as a master transcriptional activator of APM genes binding to IFN-stimulated response elements (ISREs) in an IFN signaling-independent manner. Through genetic modification of LCOR expression, we demonstrate its central role in modulation of tumor immunogenicity and ICB responsiveness. In TNBC, LCOR associates with ICB clinical response. Importantly, extracellular vesicle (EV) Lcor-messenger RNA therapy in combination with anti-PD-L1 overcame resistance and eradicated breast cancer metastasis in preclinical models. Collectively, these data support LCOR as a promising target for enhancement of ICB efficacy in TNBC, by boosting of tumor APM independently of IFN. This work was supported by the Instituto de Salud Carlos III-FSE (nos. MS17/00037 and PI18/00014) and the Cancer Research Institute, Clinic and Laboratory Integration Program (grant no. CRI2477 to T.C.-T). We also thank the AECC LAB (grant no. LABAE19007CELI) and the FERO foundation (to T.C.-T). This work was also supported by ISCIII (CIBERONC nos. CB16/12/00481, CB16/12/00241, PI18/00006 and PI21/00002), Generalitat de Catalunya (no. 2017 SGR 507) and the European Community through the Regional Development Funding Program to J. Albanell. Y.K. is supported by the Brewster Foundation, the Breast Cancer Research Foundation, the Susan G. Komen Foundation and the American Cancer Society. J. Arribas is funded by the Breast Cancer Research Foundation (no. BCRF-20-08), Instituto de Salud Carlos III (no. PI19/01181), Asociación Española Contra el Cáncer (no. GCAEC19017ARRI) and Fundación BBVA (no. CAIMI VHIO-FBBVA 2018-2021). M.M.A. is funded by MICINN and the Spanish Government (no. PGC2018-094091-B-I00). D.C. was funded by Instituto de Salud Carlos III (no. JR1800003). S.M. is funded by PERIS (no. SLT006/17/00040). The wotk of R.R.G. is funded by MICINN, the Spanish Government (no. PID2019-104948RB-I00) and the BBVA Foundation. S.B and J.P. acknowledge support from the Spanish Ministry of Science, the EMBL partnership and the CESO and CERCA Program.

Introduction: Axillary lymph node dissection (ALND) has no apparent oncologic benefit for breast cancer patients with clinically negative axillae and 1-2 positive sentinel lymph nodes so omission has been considered appropriate for this patient cohort. For patients with clinically positive nodes who are not treated with neoadjuvant chemotherapy (NAC), ALND is routinely recommended. Yet, at ALND, up to 40-57% of patients are found to have ≤ 3 positive nodes (pN1). No accurate method exists for identifying patients with minimal nodal disease who can potentially be spared the morbidity of ALND. DNA methylation (DNAm) has emerged as a potential tool for creating different classifiers to stratify cancer patients using artificial intelligence methods, such as machine learning. This study employed machine learning algorithms to create DNAm-based classifiers that efficiently stratify patients with clinically positive nodes to pN1 vs >pN1 disease. Methodology: We used publically available data from The Cancer Genome Atlas (TCGA) of breast cancer patients (n=1,006). We curated the cohort to select patients with hormone receptor-positive and HER2 negative invasive ductal carcinoma who were not treated with NAC. We only included patients who had undergone an ALND and had available DNAm (HM450 BeadChip array) data (n=58). Two Random Forest methodologies were used to obtain different combinations of DNAm features with high accuracy in stratifying pN1 and >pN1 patients. The most efficient combination of CpG sites was selected according to the Area Under the Curve (AUC) of each combination. Results: First, the differentially methylated sites (DMS, n=218) between pN1 and >pN1 patients were computed. Using all DMS displayed a good predictive potential for the selection of pN1 patients (AUC=0.88). Three different panels were obtained, containing 20 (P20), 15 (P15), and 13 (P13) genomic regions per panel. All three signatures displayed an excellent performance stratifying pN1 from >pN1 patients (AUCP20=0.98, AUCP15=0.98, and AUCP13=0.97). Furthermore, these epigenetic signatures showed a higher discriminative potential than clinical and pathological variables, such as the location of the tumor, tumor size, age, and tumor grade. Discussion: Due to the lack of data, ALND is still recommended for patients with clinically node positive disease. However, over half of patients with clinically positive nodes have minimal (pN1) nodal disease at surgery and could theoretically avoid ALND. We have designed three artificial intelligence DNAm-based panels (P20, P15, and P13) which efficiently stratify pN1 from >pN1 patients. These classifiers are more accurate than clinical and pathological variables for selecting patients with a low number of positive nodes. Furthermore, our method employs a small number of genomic regions (13 to 20), facilitating the use of PCR-based assays, such as quantitative Methylation Specific PCR (qMSP), which decreases cost compared to high-throughput technology, and increases availability and accessibility of this predictive tool. Citation Format: Maggie L. DiNome, Miguel Ensenyat-Mendez, Javier I.J. Orozco, Dennis Rünger, Jennifer L. Baker, Joanne B. Weidhaas, Diego M. Marzese. Machine learning-based DNA methylation classifiers to predict pathologic nodal stage in breast cancer patients with clinically node positive disease [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P1-01-17.

Purpose: Pituitary adenomas are one of the most common benign neoplasms of the central nervous system. Although emerging evidence suggests roles for both genetic and epigenetic factors in tumorigenesis, the degree to which these factors contribute to disease remains poorly understood. Experimental Design: A multiplatform analysis was performed to identify the genomic and epigenomic underpinnings of disease among the three major subtypes of surgically resected pituitary adenomas in 48 patients: growth hormone (GH)–secreting (n = 17), adrenocorticotropic hormone (ACTH)–secreting (n = 13, including 3 silent-ACTH adenomas), and endocrine-inactive (n = 18). Whole-exome sequencing was used to profile the somatic mutational landscape, whole-transcriptome sequencing was used to identify disease-specific patterns of gene expression, and array-based DNA methylation profiling was used to examine genome-wide patterns of DNA methylation. Results: Recurrent single-nucleotide and small indel somatic mutations were infrequent among the three adenoma subtypes. However, somatic copy-number alterations (SCNA) were identified in all three pituitary adenoma subtypes. Methylation analysis revealed adenoma subtype-specific DNA methylation profiles, with GH-secreting adenomas being dominated by hypomethylated sites. Likewise, gene-expression patterns revealed adenoma subtype-specific profiles. Integrating DNA methylation and gene-expression data revealed that hypomethylation of promoter regions are related with increased expression of GH1 and SSTR5 genes in GH-secreting adenomas and POMC gene in ACTH-secreting adenomas. Finally, multispectral IHC staining of immune-related proteins showed abundant expression of PD-L1 among all three adenoma subtypes. Conclusions: Taken together, these data stress the contribution of epigenomic alterations to disease-specific etiology among adenoma subtypes and highlight potential targets for future immunotherapy-based treatments. This article reveals novel insights into the epigenomics underlying pituitary adenomas and highlights how differences in epigenomic states are related to important transcriptome alterations that define adenoma subtypes. Clin Cancer Res; 24(17); 4126–36. ©2018 AACR.

Despite showing promise against PIK3CA-mutant breast cancers in preclinical studies, PI3K/AKT pathway inhibitors demonstrate limited clinical efficacy as monotherapy. Here, we found that histone H3K27me3 demethylase KDM6B-targeted IGFBP5 expression provides a protective mechanism for PI3K/AKT inhibitor-induced apoptosis in breast cancer cells. We found that overexpression of KDM6B and IGFBP5 in luminal breast cancer are positively associated with poorer disease outcomes. Mechanistically, KDM6B promotes IGFBP5 expression by antagonizing EZH2-mediated repression, and pharmacologic inhibition of KDM6B augments apoptotic response to PI3K/AKT inhibitor treatment. Moreover, the IGFBP5 expression is upregulated upon acquired resistance to the PI3K inhibitor GDC-0941, which is associated with an epigenetic switch from H3K27me3 to H3K27Ac at the IGFBP5 gene promoter. Intriguingly, GDC-0941–resistant breast cancer cells remained sensitive to KDM6B or IGFBP5 inhibition, indicating the dependency on the KDM6B–IGFBP5 axis to confer the survival advantage in GDC-0941–resistant cells. Our study reveals an epigenetic mechanism associated with resistance to targeted therapy and demonstrates that therapeutic targeting of KDM6B-mediated IGFBP5 expression may provide a useful approach to mitigate both intrinsic and acquired resistance to the PI3K inhibitor in breast cancer. Mol Cancer Ther; 17(9); 1973–83. ©2018 AACR.

Background Efficient treatments against metastatic melanoma dissemination are still lacking. Here, we report that low-cytotoxic concentrations of 5-aza-2′-deoxycytidine, a DNA demethylating agent, prevent in vitro 3D invasiveness of metastatic melanoma cells and reduce lung metastasis formation in vivo. Results We unravelled that this beneficial effect is in part due to MIR-199A2 re-expression by promoter demethylation. Alone, this miR showed an anti-invasive and anti-metastatic effect. Throughout integration of micro-RNA target prediction databases with transcriptomic analysis after 5-aza-2′-deoxycytidine treatments, we found that miR-199a-3p downregulates set of genes significantly involved in invasion/migration processes. In addition, analysis of data from melanoma patients showed a stage- and tissue type-dependent modulation of MIR-199A2 expression by DNA methylation. Conclusions Thus, our data suggest that epigenetic- and/or miR-based therapeutic strategies can be relevant to limit metastatic dissemination of melanoma. Electronic supplementary material The online version of this article (10.1186/s13148-018-0600-2) contains supplementary material, which is available to authorized users.