Identification of early events in serrated pathway colorectal tumorigenesis by using digital spatial profiling.

INTRODUCTION: The colorectal serrated pathway involves precursor lesions known as sessile serrated lesions (SSL) and traditional serrated adenomas (TSA). Mutations in BRAF or KRAS are crucial early events in this pathway. Additional genetic and epigenetic changes contribute to the progression of these lesions into high-grade lesions and, eventually, invasive carcinoma. METHODS: We employed digital spatial profiling to investigate the transcriptional changes associated with SSL and TSA. The genes identified are confirmed by immunohistochemical (IHC) staining. Colorectal (CRC) cell lines with CEACAM6 overexpression and knockdown were established to study the roles of CEACAM6 on tumorigenesis of CRC. RESULTS: Ten genes were upregulated in SSL and TSA, and seven were upregulated in both types of lesions. IHC staining confirmed overexpression of CEACAM6, LCN2, KRT19, and lysozyme in SSL and TSA. CEACAM6 expression is an early event in the serrated pathway but a late event in the conventional pathway. Using cell line models, we confirmed that CEACAM6 promotes CRC cells' proliferation, migration, and invasion abilities. CONCLUSION: These results highlight that the transcriptional changes in the early stages of tumorigenesis exhibit relative uniformity. Identifying these early events may hold significant promise in elucidating the mechanisms behind tumor initiation.

Regulating epithelial-mesenchymal plasticity from 3D genome organization.

Epithelial-mesenchymal transition (EMT) is a dynamic process enabling polarized epithelial cells to acquire mesenchymal features implicated in development and carcinoma progression. As our understanding evolves, it is clear the reversible execution of EMT arises from complex epigenomic regulation involving histone modifications and 3-dimensional (3D) genome structural changes, leading to a cascade of transcriptional events. This review summarizes current knowledge on chromatin organization in EMT, with a focus on hierarchical structures of the 3D genome and chromatin accessibility changes.

Clinicopathological features and cancer transcriptomic profiling of poorly cohesive gastric carcinoma subtypes.

Gastric poorly cohesive carcinoma (PCC) manifests with a diffuse pattern and diverse tumor cell morphologies, often indicating a more unfavorable prognosis. Recent consensus has reclassified PCC based on the proportion of signet-ring cells (SRCs) in tumors for research purposes. The two most distinct subtypes, poorly cohesive carcinoma not otherwise specified (PCC-NOS) and signet-ring cell carcinoma (SRCC), are characterized by less than 10% and more than 90% SRCs, respectively. However, research comparing the clinicopathological and transcriptomic differences between these subtypes remains limited. In this study, we conducted a comparative analysis of clinicopathological features in 55 advanced-stage PCCs, consisting of 43 PCC-NOS and 12 SRCC cases. Subsequently, 12 PCC-NOS and 5 SRCC cases were randomly selected for initial cancer-related gene expression profiling and pathway enrichment analysis using the GeoMx digital spatial profiler, followed by validation in a separate validation group comprising 16 PCC-NOS and 6 SRCC cases. These transcriptomic findings were then correlated with tumor morphology and clinicopathological data. PCC-NOS cases exhibited larger tumor size, a higher prevalence of pathological N3 disease, and a worse 1-year progression-free survival rate compared to SRCC cases. Clustering of PCC-NOS and SRCC was successfully achieved using the GeoMx Cancer Transcriptome Atlas. Among all studied genes, only MMP7 showed differential expression, with its overexpression significantly associated with the PCC-NOS subtype, increased perineural invasion, and earlier disease progression. Pathway analysis revealed significantly enriched pathways in PCC-NOS related to vesicle-mediated transport, adaptive immune systems, oncogenic signaling, and extracellular matrix organization, while SRCC displayed significant enrichment in pathways associated with respiratory electron transport and the cell cycle. In conclusion, this study compares and correlates clinicopathological features and transcriptomic data between PCC-NOS and SRCC at advanced stages, employing the latest consensus classification and a novel platform for analysis.

Secretome from Magnetically Stimulated Muscle Exhibits Anticancer Potency: Novel Preconditioning Methodology Highlighting HTRA1 Action.

Briefly (10 min) exposing C2C12 myotubes to low amplitude (1.5 mT) pulsed electromagnetic fields (PEMFs) generated a conditioned media (pCM) that was capable of mitigating breast cancer cell growth, migration, and invasiveness in vitro, whereas the conditioned media harvested from unexposed myotubes, representing constitutively released secretome (cCM), was less effective. Administering pCM to breast cancer microtumors engrafted onto the chorioallantoic membrane of chicken eggs reduced tumor volume and vascularity. Blood serum collected from PEMF-exposed or exercised mice allayed breast cancer cell growth, migration, and invasiveness. A secretome preconditioning methodology is presented that accentuates the graded anticancer potencies of both the cCM and pCM harvested from myotubes, demonstrating an adaptive response to pCM administered during early myogenesis that emulated secretome-based exercise adaptations observed in vivo. HTRA1 was shown to be upregulated in pCM and was demonstrated to be necessary and sufficient for the anticancer potency of the pCM; recombinant HTRA1 added to basal media recapitulated the anticancer effects of pCM and antibody-based absorption of HTRA1 from pCM precluded its anticancer effects. Brief and non-invasive PEMF stimulation may represent a method to commandeer the secretome response of muscle, both in vitro and in vivo, for clinical exploitation in breast and other cancers.

Whole transcriptome profiling of placental pathobiology in SARS-CoV-2 pregnancies identifies placental dysfunction signatures.

Objectives: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) virus infection in pregnancy is associated with higher incidence of placental dysfunction, referred to by a few studies as a 'preeclampsia-like syndrome'. However, the mechanisms underpinning SARS-CoV-2-induced placental malfunction are still unclear. Here, we investigated whether the transcriptional architecture of the placenta is altered in response to SARS-CoV-2 infection. Methods: We utilised whole-transcriptome, digital spatial profiling, to examine gene expression patterns in placental tissues from participants who contracted SARS-CoV-2 in the third trimester of their pregnancy (n = 7) and those collected prior to the start of the coronavirus disease 2019 (COVID-19) pandemic (n = 9). Results: Through comprehensive spatial transcriptomic analyses of the trophoblast and villous core stromal cell subpopulations in the placenta, we identified SARS-CoV-2 to promote signatures associated with hypoxia and placental dysfunction. Notably, genes associated with vasodilation (NOS3), oxidative stress (GDF15, CRH) and preeclampsia (FLT1, EGFR, KISS1, PAPPA2) were enriched with SARS-CoV-2. Pathways related to increased nutrient uptake, vascular tension, hypertension and inflammation were also enriched in SARS-CoV-2 samples compared to uninfected controls. Conclusions: Our findings demonstrate the utility of spatially resolved transcriptomic analysis in defining the underlying pathogenic mechanisms of SARS-CoV-2 in pregnancy, particularly its role in placental dysfunction. Furthermore, this study highlights the significance of digital spatial profiling in mapping the intricate crosstalk between trophoblasts and villous core stromal cells, thus shedding light on pathways associated with placental dysfunction in pregnancies with SARS-CoV-2 infection.

The microtubule inhibitor eribulin demonstrates efficacy in platinum-resistant and refractory high-grade serous ovarian cancer patient-derived xenograft models.

Background: Despite initial response to platinum-based chemotherapy and PARP inhibitor therapy (PARPi), nearly all recurrent high-grade serous ovarian cancer (HGSC) will acquire lethal drug resistance; indeed, ~15% of individuals have de novo platinum-refractory disease. Objectives: To determine the potential of anti-microtubule agent (AMA) therapy (paclitaxel, vinorelbine and eribulin) in platinum-resistant or refractory (PRR) HGSC by assessing response in patient-derived xenograft (PDX) models of HGSC. Design and methods: Of 13 PRR HGSC PDX, six were primary PRR, derived from chemotherapy-naïve samples (one was BRCA2 mutant) and seven were from samples obtained following chemotherapy treatment in the clinic (five were mutant for either BRCA1 or BRCA2 (BRCA1/2), four with prior PARPi exposure), recapitulating the population of individuals with aggressive treatment-resistant HGSC in the clinic. Molecular analyses and in vivo treatment studies were undertaken. Results: Seven out of thirteen PRR PDX (54%) were sensitive to treatment with the AMA, eribulin (time to progressive disease (PD) ⩾100 days from the start of treatment) and 11 out of 13 PDX (85%) derived significant benefit from eribulin [time to harvest (TTH) for each PDX with p < 0.002]. In 5 out of 10 platinum-refractory HGSC PDX (50%) and one out of three platinum-resistant PDX (33%), eribulin was more efficacious than was cisplatin, with longer time to PD and significantly extended TTH (each PDX p < 0.02). Furthermore, four of these models were extremely sensitive to all three AMA tested, maintaining response until the end of the experiment (120d post-treatment start). Despite harbouring secondary BRCA2 mutations, two BRCA2-mutant PDX models derived from heavily pre-treated individuals were sensitive to AMA. PRR HGSC PDX models showing greater sensitivity to AMA had high proliferative indices and oncogene expression. Two PDX models, both with prior chemotherapy and/or PARPi exposure, were refractory to all AMA, one of which harboured the SLC25A40-ABCB1 fusion, known to upregulate drug efflux via MDR1. Conclusion: The efficacy observed for eribulin in PRR HGSC PDX was similar to that observed for paclitaxel, which transformed ovarian cancer clinical practice. Eribulin is therefore worthy of further consideration in clinical trials, particularly in ovarian carcinoma with early failure of carboplatin/paclitaxel chemotherapy.

The effect of inhibition of receptor tyrosine kinase AXL on DNA damage response in ovarian cancer.

AXL is a receptor tyrosine kinase that is often overexpressed in cancers. It contributes to pathophysiology in cancer progression and therapeutic resistance, making it an emerging therapeutic target. The first-in-class AXL inhibitor bemcentinib (R428/BGB324) has been granted fast track designation by the U.S. Food and Drug Administration (FDA) in STK11-mutated advanced metastatic non-small cell lung cancer and was also reported to show selective sensitivity towards ovarian cancers (OC) with a Mesenchymal molecular subtype. In this study, we further explored AXL's role in mediating DNA damage responses by using OC as a disease model. AXL inhibition using R428 resulted in the increase of DNA damage with the concurrent upregulation of DNA damage response signalling molecules. Furthermore, AXL inhibition rendered cells more sensitive to the inhibition of ATR, a crucial mediator for replication stress. Combinatory use of AXL and ATR inhibitors showed additive effects in OC. Through SILAC co-immunoprecipitation mass spectrometry, we identified a novel binding partner of AXL, SAM68, whose loss in OC cells harboured phenotypes in DNA damage responses similar to AXL inhibition. In addition, AXL- and SAM68-deficiency or R428 treatment induced elevated levels of cholesterol and upregulated genes in the cholesterol biosynthesis pathway. There might be a protective role of cholesterol in shielding cancer cells against DNA damage induced by AXL inhibition or SMA68 deficiency.

Nodal reactive proliferation of monocytoid B-cells may represent atypical memory B-cells.

BACKGROUND: Reactive lymphadenopathies such as toxoplasmosis and cytomegalovirus lymphadenitis are associated with monocytoid cell proliferation. Monocytoid cells are B-lymphocytes with an undetermined subset. METHODS: Using digital spatial profiling whole transcriptome analyses, this study compared monocytoid and control B-cells. The B-cell subset of monocytoid cells was assigned according to gene expression profiles. RESULTS: This study identified 466 differentially expressed genes between monocytoid and control B-cells. The cellular deconvolution algorithm identified monocytoid cells as memory B-cells instead of as naïve B-cells. A comparison of the upregulated genes revealed that atypical memory B-cells had the largest number of genes overlapping with monocytoid cells compared with other memory B-cell subsets. Atypical memory B-cell markers, namely TBX21 (T-bet), FCRL4 (IRTA1), and ITGAX (CD11c), were all upregulated in monocytoid cells. Similar to atypical memory B-cells, monocytoid cells exhibited (1) upregulated transcription factors (TBX21, TOX), (2) upregulated genes associated with B-cell inhibition (FCRL5, FCRL4) and downregulated genes associated with B-cell activation (PIK3CG, NFKB1A, CD40), (3) downregulated cell cycle-related genes (CDK6, MYC), and (4) downregulated cytokine receptors (IL4R). This study also analyzed the expression of monocytoid cell signature genes in various memory B-cell subsets. Atypical memory B-cells exhibited a gene expression pattern similar to that of monocytoid cells, but other memory B-cell subsets did not. Furthermore, monocytoid cells and marginal zone lymphomas differed in gene expression profiles. CONCLUSION: Spatial transcriptomic analyses indicated that monocytoid cells may be atypical memory B-cells.

Immune-Hot tumor features associated with recurrence in early-stage ovarian clear cell carcinoma.

Ovarian clear cell carcinoma (OCCC) is a distinct histotype of ovarian cancer, which usually presages a worse prognosis upon recurrence. Identifying patients at risk for relapse is an unmet need to improve outcomes. A retrospective cohort analysis of 195 early-stage OCCC patients diagnosed between January 2011 and December 2019 at National Taiwan University Hospital was conducted to identify prognostic factors for recurrence, progression-free survival (PFS) and overall survival (OS). Molecular profiling of tumors was performed in a case-controlled cohort matched for adjuvant therapy for biomarker discovery. Multivariate Cox proportional hazard model revealed that paclitaxel-based chemotherapy was associated with better PFS than nonpaclitaxel chemotherapy (HR = 0.19, P = .006). The addition of bevacizumab was associated with better PFS, compared to no bevacizumab (HR = 0.09, P = .02). Neither showed significant improvement in OS. Recurrence is associated with an Immune-Hot tumor feature (P = .03), the CTLA-4-high subtype (P = .01) and increased infiltration of immune cells in general. The Immune-Hot feature (HR = 3.39, P = .005) and the CTLA-4-high subtype (HR = 2.13, P = .059) were associated with worse PFS. Immune-Hot tumor features could prognosticate recurrence in early-stage OCCC.

3D genome organization in the epithelial-mesenchymal transition spectrum.

BACKGROUND: The plasticity along the epithelial-mesenchymal transition (EMT) spectrum has been shown to be regulated by various epigenetic repertoires. Emerging evidence of local chromatin conformation changes suggests that regulation of EMT may occur at a higher order of three-dimensional genome level. RESULTS: We perform Hi-C analysis and combine ChIP-seq data across cancer cell lines representing different EMT states. We demonstrate that the epithelial and mesenchymal genes are regulated distinctively. We find that EMT genes are regulated within their topologically associated domains (TADs), with only a subset of mesenchymal genes being influenced by A/B compartment switches, indicating topological remodeling is required in the transcriptional regulation of these genes. At the TAD level, epithelial and mesenchymal genes are associated with different regulatory trajectories. The epithelial gene-residing TADs are enriched with H3K27me3 marks in the mesenchymal-like states. The mesenchymal gene-residing TADs, which do not show enrichment of H3K27me3 in epithelial-like states, exhibit increased interaction frequencies with regulatory elements in the mesenchymal-like states. CONCLUSIONS: We propose a novel workflow coupling immunofluorescence and dielectrophoresis to unravel EMT heterogeneity at single-cell resolution. The predicted three-dimensional structures of chromosome 10, harboring Vimentin, identify cell clusters of different states. Our results pioneer a novel avenue to decipher the complexities underlying the regulation of EMT and may infer the barriers of plasticity in the 3D genome context.

Corrigendum: Modulated TRPC1 Expression Predicts Sensitivity of Breast Cancer to Doxorubicin and Magnetic Field Therapy: Segue Towards a Precision Medicine Approach.

[This corrects the article DOI: 10.3389/fonc.2021.783803.].

Genome-wide association study of primary dysmenorrhea in the Taiwan Biobank validates associations near the NGF and IL1 gene loci.

Using the Taiwan Biobank, we aimed to identify traits and genetic variations that could predispose Han Chinese women to primary dysmenorrhea. Cases of primary dysmenorrhea included those who self-reported "frequent dysmenorrhea" in a dysmenorrhea-related Taiwan Biobank questionnaire, and those who have been diagnosed with severe dysmenorrhea by a physician. Controls were those without self-reported dysmenorrhea. Customized Axiom-Taiwan Biobank Array Plates were used to perform whole-genome genotyping, PLINK was used to perform association tests, and HaploReg was used to conduct functional annotations of SNPs and bioinformatic analyses. The GWAS analysis included 1186 cases and 24,020 controls. We identified 53 SNPs that achieved genome-wide significance (P < 5 × 10-8, which clustered in 2 regions. The first SNP cluster was on chromosome 1, and included 24 high LD (R2 > 0.88) variants around the NGF gene (lowest P value of 3.83 × 10-13 for rs2982742). Most SNPs occurred within NGF introns, and were predicted to alter regulatory binding motifs. The second SNP cluster was on chromosome 2, including 7 high LD (R2 > 0.94) variants around the IL1A and IL1B loci (lowest P value of 7.43 × 10-10 for rs11676014) and 22 SNPs that did not reach significance after conditional analysis. Most of these SNPs resided within IL1A and IL1B introns, while 2 SNPs may be in the promoter histone marks or promoter flanking regions of IL1B. To conclude, data from this study suggest that NGF, IL1A, and IL1B may be involved in the pathogenesis of primary dysmenorrhea in the Han Chinese in Taiwan.

Weekly versus tri-weekly paclitaxel with carboplatin for first-line treatment in women with epithelial ovarian cancer.

BACKGROUND: Epithelial ovarian cancer is the sixth most common cancer worldwide: 295,414 new cases were diagnosed in 2018, with 184,799 deaths. The lack of an effective screening strategy has led to the majority of women being diagnosed at an advanced stage. For these women, intravenous carboplatin combined with paclitaxel for six cycles is widely accepted as the standard first-line treatment for epithelial ovarian cancer, in combination with debulking surgery. However, there is conflicting evidence regarding the optimal dosing schedule of paclitaxel when combined with carboplatin in this setting. OBJECTIVES: To compare the efficacy and tolerability of intravenous weekly paclitaxel with that of tri-weekly paclitaxel, in combination with intravenous carboplatin, as first-line treatment for epithelial ovarian cancer (defined as epithelial ovarian, primary peritoneal and fallopian tube cancer). SEARCH METHODS: We searched CENTRAL, MEDLINE, and Embase databases for relevant studies up to 15 November 2021, using keywords and MeSH terms. We additionally handsearched conference libraries, online clinical trial databases and screened through lists of retrieved references. SELECTION CRITERIA: We Included randomised controlled trials (RCTs) comparing weekly paclitaxel in combination with carboplatin versus tri-weekly paclitaxel in combination with carboplatin, for treatment of newly-diagnosed epithelial ovarian cancer. DATA COLLECTION AND ANALYSIS: We used the hazard ratio (HR) to estimate the primary efficacy outcomes progression-free (PFS) and overall survival (OS). We used the risk ratio (RR) to estimate the primary toxicity outcome of severe neutropenia and secondary outcomes of quality of life (QoL) and treatment-related adverse events. Two review authors independently selected studies, extracted data, and assessed risk of bias, using standard Cochrane methodological procedures. We included individual participant data (IPD) from one of the included studies, ICON-8, provided by the study team. We analysed data using a random-effects model in Review Manager 5.4 software. Additionally, we reconstructed IPD for PFS and OS data from published Kaplan-Meier curves from all studies and subsequently pooled these to analyse the two primary efficacy outcomes. MAIN RESULTS: From 2469 records, we identified four eligible RCTs with data for 3699 participants. All eligible studies were included in the main meta-analysis and reported on PFS and OS. There was likely a slight improvement in PFS when paclitaxel was dosed weekly compared to tri-weekly (HR 0.89, 95% confidence interval (CI) 0.81 to 0.98; 4 studies, 3699 participants; moderate-certainty evidence). We found little to no improvement in OS when paclitaxel was dosed weekly compared to tri-weekly (HR 0.92, 95% CI 0.79 to 1.06; 4 studies, 3699 participants; high-certainty evidence). There was likely little to no difference in high-grade (grade 3 or 4) neutropenia when paclitaxel was dosed weekly compared to tri-weekly (RR 1.11, 95% CI 0.86 to 1.43; 4 studies, 3639 participants; moderate-certainty evidence). However, weekly paclitaxel increased high-grade (grade 3 or 4) anaemia when compared to tri-weekly dosing (RR 1.57, 95% CI 1.12 to 2.20; 4 studies, 3639 participants; high-certainty evidence). There may be little to no difference in high-grade neuropathy when paclitaxel was dosed weekly compared to tri-weekly (RR 1.12, 95% CI 0.64 to 1.94; 4 studies, 3639 participants; low-certainty evidence). The overall risk of detection bias and performance bias was low for OS, but was unclear for other outcomes, as treatments were not blinded. The risk of bias in other domains was low or unclear. We note that OS data were immature for three of the included studies (GOG-0262, ICON-8 and MITO-7). AUTHORS' CONCLUSIONS: Weekly paclitaxel combined with carboplatin for first-line treatment of epithelial ovarian cancer likely improves PFS slightly (moderate-certainty evidence) but not OS (high-certainty evidence), compared to tri-weekly paclitaxel combined with carboplatin. However, this was associated with increased risk for high-grade anaemia, treatment discontinuation, dose delays and dose omissions (high- to low-certainty evidence). Our findings may not apply to women receiving bevacizumab in first-line therapy, those receiving treatment in the neo-adjuvant setting, or those with rare subtypes of clear cell or mucinous ovarian cancer.

Applications of the Chick Chorioallantoic Membrane as an Alternative Model for Cancer Studies.

A variety of in vivo experimental models have been established for the studies of human cancer using both cancer cell lines and patient-derived xenografts (PDXs). In order to meet the aspiration of precision medicine, the in vivomurine models have been widely adopted. However, common constraints such as high cost, long duration of experiments, and low engraftment efficiency remained to be resolved. The chick embryo chorioallantoic membrane (CAM) is an alternative model to overcome some of these limitations. Here, we provide an overview of the applications of the chick CAM model in the study of oncology. The CAM model has shown significant retention of tumor heterogeneity alongside increased xenograft take rates in several PDX studies. Various imaging techniques and data analysis have been applied to study tumor metastasis, angiogenesis, and therapeutic response to novel agents. Lastly, to practically illustrate the feasibility of utilizing the CAM model, we summarize the general protocol used in a case study utilizing an ovarian cancer PDX.

The CAM Model-Q&A with Experts.

The chick chorioallantoic membrane (CAM), as an extraembryonic tissue layer generated by the fusion of the chorion with the vascularized allantoic membrane, is easily accessible for manipulation. Indeed, grafting tumor cells on the CAM lets xenografts/ovografts develop in a few days for further investigations. Thus, the CAM model represents an alternative test system that is a simple, fast, and low-cost tool to study tumor growth, drug response, or angiogenesis in vivo. Recently, a new era for the CAM model in immune-oncology-based drug discovery has been opened up. Although there are many advantages offering extraordinary and unique applications in cancer research, it has also disadvantages and limitations. This review will discuss the pros and cons with experts in the field.

Evolution of CP2 transcription factors in Hexapoda.

The CP2 transcription factors are highly conserved in metazoans, where they are divided into two groups: grainyhead and late SV40 factor (LSF). We traced their evolutionary history in the Hexapoda using over 500 insect transcriptomes, to test the hypothesis that the evolution of holometaboly involved novel isoforms of these genes. All insects appear to express at least one grainyhead and one LSFlike gene, regardless of life cycle, as in most known metazoa. No major evolutionary events in these gene families occurred during the evolution of insects.

Epigenetic derepression converts PPARγ into a druggable target in triple-negative and endocrine-resistant breast cancers.

Clinical trials repurposing peroxisome proliferator-activated receptor-gamma (PPARγ) agonists as anticancer agents have exhibited lackluster efficacy across a variety of tumor types. Here, we report that increased PPARG expression is associated with a better prognosis but is anticorrelated with histone deacetylase (HDAC) 1 and 2 expressions. We show that HDAC overexpression blunts anti-proliferative and anti-angiogenic responses to PPARγ agonists via transcriptional and post-translational mechanisms, however, these can be neutralized with clinically approved and experimental HDAC inhibitors. Supporting this notion, concomitant treatment with HDAC inhibitors was required to license the tumor-suppressive effects of PPARγ agonists in triple-negative and endocrine-refractory breast cancer cells, and combination therapy also restrained angiogenesis in a tube formation assay. This combination was also synergistic in estrogen receptor-alpha (ERα)-positive cells because HDAC blockade abrogated ERα interference with PPARγ-regulated transcription. Following a pharmacokinetics optimization study, the combination of rosiglitazone and a potent pan-HDAC inhibitor, LBH589, stalled disease progression in a mouse model of triple-negative breast cancer greater than either of the monotherapies, while exhibiting a favorable safety profile. Our findings account for historical observations of de-novo resistance to PPARγ agonist monotherapy and propound a therapeutically cogent intervention against two aggressive breast cancer subtypes.

High prevalence of APOA1/C3/A4/A5 alterations in luminal breast cancers among young women in East Asia.

In East Asia, the breast cancer incidence rate among women aged <50 years has rapidly increased. Emerging tumors are distinctly characterized by a high prevalence of estrogen receptor (ER)-positive/human epidermal growth factor receptor (HER2)-negative cancer. In the present study, we identified unique genetic alterations in these emerging tumors. We analyzed gene copy number variations (CNVs) in breast tumors from 120 Taiwanese patients, and obtained public datasets of CNV and gene expression (GE). The data regarding CNV and GE were separately compared between East Asian and Western patients, and the overlapping genes identified in the comparisons were explored to identify the gene-gene interaction networks. In the age <50 years/ER + /HER2- subgroup, tumors of East Asian patients exhibited a higher frequency of copy number loss in APOA1/C3/A4/A5, a lipid-metabolizing gene cluster (33 vs. 10%, P < .001) and lower APOA1/C3/A4/A5 expressions than tumors of Western patients. These copy number loss related- and GE-related results were validated in another Taiwanese cohort and in two GE datasets, respectively. The copy number loss was significantly associated with poor survival among Western patients, but not among East Asian patients. Lower APOA1, APOC3, and APOA5 expressions were associated with higher ESTIMATE immune scores, indicating an abundance of tumor-infiltrating immune cells. In conclusion, APOA1/C3/A4/A5 copy number loss was more prevalent in luminal breast tumors among East Asian women aged <50 years, and its immunomodulatory effect on the tumor microenvironment possibly plays various roles in the tumor biology of East Asian patients.