Association between miR-27a rs895819 polymorphism and breast cancer susceptibility: Evidence based on 6118 cases and 7042 controls

Background:Polymorphism in miR-27a rs895819 has been associated with breast cancer (BC) risk, but studies have reported inconsistent results. This meta-analysis investigated the possible association between miR-27a rs895819 polymorphism and BC risk.Methods:PubMed, EMBASE, Google Scholar, and the Chinese National Knowledge Infrastructure (CNKI) databases were systematically searched to identify relevant studies in English and Chinese. Meta-analyses were performed to examine the association between miR-27a rs895819 and BC susceptibility.Results:A total of 16 case–control studies involving 6118 cases and 7042 controls were included. Analysis using five genetic models suggested no significant association between miR-27a rs895819 polymorphism and BC risk in the total population, or specifically in Asian or Chinese subpopulations. In the Caucasian subpopulation, however, the G-allele and AG genotype at rs895819 were significantly associated with decreased BC risk according to the allelic model (OR 0.90, 95% CI 0.84–0.97, P = .004) and heterozygous model (OR 0.89, 95% CI 0.81–089, P = .02), while the wild-type AA genotype was significantly associated with increased BC risk according to the dominant model (OR 1.13, 95% CI 1.03–1.24, P = .007).Conclusion:These results indicate that among Caucasians, the wild-type AA genotype at rs895819 may confer increased susceptibility to BC, while the G-allele and AG genotype may be protective factors. These conclusions should be verified in large, well-designed studies.     

Extracellular vesicles from triple negative breast cancer promote pro-inflammatory macrophages associated with better clinical outcome

Tumor associated macrophages (TAMs), which differentiate from circulating monocytes, are pervasive across human cancers and comprise heterogeneous populations. The contribution of tumor-derived signals to TAM heterogeneity is not well understood. In particular, tumors release both soluble factors and extracellular vesicles (EVs), whose respective impact on TAM precursors may be different. Here, we show that triple negative breast cancer cells (TNBCs) release EVs and soluble molecules promoting monocyte differentiation toward distinct macrophage fates. EVs specifically promoted proinflammatory macrophages bearing an interferon response signature. The combination in TNBC EVs of surface CSF-1 promoting survival and cargoes promoting cGAS/STING or other activation pathways led to differentiation of this particular macrophage subset. Notably, macrophages expressing the EV-induced signature were found among patients’ TAMs. Furthermore, higher expression of this signature was associated with T cell infiltration and extended patient survival. Together, this data indicates that TNBC-released CSF-1-bearing EVs promote a tumor immune microenvironment associated with a better prognosis in TNBC patients.

Tumors are infiltrated by different populations of immune cells, macrophages, in particular, being major components of the tumor microenvironment. Tumor-associated macrophages (TAMs) favor tumor progression, promoting cancer cell invasion and metastasis in mouse models (1). Recent single-cell analyses of human cancers revealed the heterogeneity of macrophage populations, thus challenging our understanding of TAM biology (2–4). TAMs derive from circulating monocytes that are recruited into the tumor via the CCL2-CCR2 chemokine signaling pathway (5, 6). The fate of monocytes is not predetermined and largely depend on the microenvironmental cues they encounter (7). Specifically, the identity of tumor-derived factors that contribute to TAM heterogeneity and the mechanisms underlying intratumoral monocyte differentiation remain unclear.Among the signals that can impact TAM differentiation and activation, cytokines and chemokines are well-characterized factors (8); extracellular vesicles (EVs), however, represent novel candidates. EVs are complex vehicles of intercellular communication and were suggested to have an impact on macrophage activation (9–12). EVs, such as exosomes, ectosomes, microvesicles, and oncosomes, are membrane-enclosed structures that contain proteins and nucleic acids and can be released into the extracellular environment by all cell types, including cancer cells (13, 14). Once released, EVs can interact with recipient cells and modulate their function (15). Particularly, EVs released by cancer cells play an important role in shaping the tumor immune microenvironment. EVs were shown to modulate lymphocytes and myeloid cell functions in cancer by triggering either protumor or anti-tumor immune responses (16, 17), which may depend on numerous factors, such as the cancer type, stage, or EV subtype analyzed (18). Here, we address the specific contribution of tumor-derived EVs, as compared to the tumor-derived soluble factors, in driving TAM heterogeneity. For this, we focus on human breast cancer since these tumors are highly infiltrated with macrophages (1). Our results confirm a striking functional difference of EVs and soluble factors in tuning TAM profile that we attribute to the combination of survival and activation signals carried by EVs. Furthermore, we unravel an unexpected ability of TNBC-EVs to promote an inflammatory tumor microenvironment associated with a better clinical outcome.     

miR-140靶向调控SOX2在结肠癌中的作用机制研究

目的 分析miR-140在结肠癌中的作用机制.方法 qRT-PCR检测miR-140在结肠癌细胞和组织中的表达;CCK8法、细胞划痕实验检测miR-140对结肠癌HT29细胞增殖和迁移的影响.TargetScan筛选miR-140的潜在靶基因并通过双荧光素酶报告基因试验进行验证;采用qRT-PCR和Western bl...     

miR-383靶向Notch1对结肠癌HCT116细胞增殖和迁移的影响

目的 分析miR-383和Notch1在结肠癌中的作用及机制.方法 选择2017年4月至2020年3月在河北北方学院附属第一医院经病理检查确诊为结肠癌的74例患者,收集其经手术切除的肿瘤组织及癌旁正常组织(距肿瘤边缘>3 cm).采用TargetScan预测miR-383的潜在靶基因,采用双荧光素酶报告基因实验、逆转录...     

miR-132 inhibits colorectal cancer invasion and metastasis via directly targeting ZEB2

AIM:To investigate the biological role and underlying mechanism of miR-132 in colorectal cancer(CRC)progression and invasion.METHODS:Quantitative RT-PCR analysis was used to examine the expression levels of miR-132 in five CRC cell lines(SW480,SW620,HCT116,HT29 and LoVo)and a normal colonic cell line NCM460,as well as in tumor tissues with or without metastases.The KaplanMeier method was used to analyze the prognostic significance of miR-132 in CRC patients.The biological effects of miR-132 were assessed in CRC cell lines using the transwell assay.Quantitative RT-PCR and western blot analyses were employed to evaluate the expression of miR-132 targets.The regulation of ZEB2 by miR-132was confirmed using the luciferase activity assay.RESULTS:miR-132 was significantly down-regulated in the CRC cell lines compared with the normal colonic cell line(P<0.05),as well as in the CRC tissues withdistant metastases compared with the tissues without metastases(10.52±4.69 vs 23.11±7.84)(P<0.001).Down-regulation of miR-132 was associated with tumor size(P=0.016),distant metastasis(P=0.002),and TNM stage(P=0.020)in CRC patients.Kaplan-Meier survival curve analysis indicated that patients with low expression of miR-132 tended to have worse diseasefree survival than patients with high expression of miR-132(P<0.001).Moreover,ectopic expression of miR-132 markedly inhibited cell invasion(P<0.05)and the epithelial-mesenchymal transition(EMT)in CRC cell lines.Further investigation revealed ZEB2,an EMT regulator,was a downstream target of miR-132.CONCLUSION:Our study indicated that miR-132 plays an important role in the invasion and metastasis of CRC.     

MicroRNA-496 inhibits triple negative breast cancer cell proliferation by targeting Del-1

Del-1 has been linked to the pathogenesis of various cancers, including breast cancer. However, the regulation of Del-1 expression remains unclear. We previously reported the interaction between microRNA-137 (miR-137) and the Del-1 gene. In this study, we investigated miR-496 and miR-137 as regulators of Del-1 expression in triple negative breast cancer (TNBC). Del-1 mRNA and miR-496 were measured by quantitative PCR in breast cancer cells (MDA-MB-231, MCF7, SK-BR3, and T-47D) and tissues from 30 patients with TNBC. The effects of miR-496 on cell proliferation, migration, and invasion were determined with MTT, wound healing, and Matrigel transwell assays, respectively. In MDA-MB-231 cells, miR-496 levels were remarkably low and Del-1 mRNA levels were higher than in other breast cancer cell lines. Luciferase reporter assays revealed that miR-496 binds the 3′-UTR of Del-1 and Del-1 expression is downregulated by miR-496 mimics. Furthermore, miR-496 inhibited the proliferation, migration, and invasion of MDA-MB-231 cells. The effects of miR-496 on cell proliferation were additive with those of miR-137, another miRNA that regulates Del-1 expression. Moreover, in the 30 TNBC specimens, miR-496 was downregulated (P < .005) and the levels of Del-1 in the plasma were significantly elevated as compared with in normal controls (P = .0142). The Cancer Genome Atlas (TCGA) data showed the correlation of miR-496 expression with better overall survival in patients with early TNBC. In in silico and in vitro analyses, we showed that Del-1 is a target of miR-496 in TNBC and thereby affects cancer progression. Our findings suggest that miR-496 and miR-137 additively target Del-1 and act as modulating factors in TNBC. They are potentially new biomarkers for patients with TNBC.     

miR-132 inhibits lung cancer cell migration and invasion by targeting SOX4

Background

Multiple MicroRNAs (miRNAs) have been identified in the development and progression of lung cancer. However, the expression and roles of miR-132 in non-small cell lung cancer (NSCLC) remain largely undefined. The aim of this study is to investigate the biological functions and its molecular mechanisms of miR-132 in human lung cancer cells.

Methods

miR-132 expression was measured in human lung cancer cell lines by quantitative real-time PCR (qRT-PCR). The cells migration and invasion ability were measured by wound healing assay and transwell assay. The influence of miR-132 on tumor progression in vivo was monitored using NSCLC xenografts in nude mice. The target gene of miR-132 was determined by luciferase assay and western blot.

Results

The expression level of miR-132 was dramatically decreased in examined lung cancer cell lines. Then, we found that introduction of miR-132 significantly suppressed the migration and invasion of lung cancer cells in vitro. Besides, miR-132 overexpression could also inhibit tumor growth in the nude mice. Further studies indicated that the sex determining region Y-box 4 (SOX4) is a target gene of miR-132. SOX4 re-introduction could reverse the anti-invasion role of miR-132.

Conclusions

Our finding provides new insight into the mechanism of NSCLC progression. Therapeutically, miR-132 may serve as a potential target in the treatment of human lung cancer.     

肺癌细胞与组织中miR-100、miR-148a的表达变化及临床意义

目的：观察微小RNA 100（miR-100）、微小RNA 148a（miR-148a）在肺癌细胞与组织中的表达,并探讨其临床意义。方法采用RT-PCR方法检测人肺癌细胞系NCI-H1299、NCI-H358、H460、A549及人正常支气管上皮细胞系HBE,以及肺癌及其癌旁组织中miR-100、miR-148a表达;分析肺癌组织中miR-100、miR-148a表达与其临床病理参数的关系。结果与HBE细胞相比,miR-100在NCI-H1299、NCI-H358及A549细胞中表达升高,在H460细胞表达降低,P均＜0．05;miR-148a在NCI-H358、H460细胞中表达升高,在A549细胞中表达降低,P均＜0．05。与癌旁组织相比,肺癌组织中miR-100表达降低,但差异无统计学意义（P＝0．400）;miR-148a表达升高（P＝0．036）。肺癌组织中miR-100、miR-148a表达水平与患者性别、年龄、病理类型无关;有淋巴结转移者肺癌组织中miR-100表达水平较无淋巴结转移者低（P＝0．016）。结论 miR-100、miR-148a在肺癌细胞中表达异常;在肺癌组织中,miR-100表达降低,miR-148a表达增加,二者可能参与肺癌的发生、发展。     

miR-539通过靶向调控DCLK1抑制非小细胞肺癌的侵袭能力

目的 探讨非小细胞肺癌组织中miR-539的表达水平及其抑制肺癌细胞侵袭的作用机制.方法 通过基因表达数据库dbDEMC分析miR-539在非小细胞肺癌组织及正常肺组织中的表达量差异.根据235例miR-539高表达的非小细胞肺癌患者和102例miR-539低表达的非小细胞肺癌患者随访资料,分析miR-539与非小细胞...     

肿瘤相关巨噬细胞在原发性肝癌发生发展中的作用

近年来,炎症反应与肿瘤的关系受到了广泛关注。肿瘤相关巨噬细胞(TAM)对肿瘤的生长增殖、代谢转移等都具有重要作用,许多研究表明TAM多为M2表型,已经证实其在原发性肝癌中具有促进肿瘤生长、代谢、转移及血管生成等作用。通过促M2型巨噬细胞向M1型转化,改变了肝癌细胞的一些生物学表现,这也许可能成为一种新的肝癌治疗策略。就近年来TAM与原发性肝癌进展的相关性研究进展及可能的治疗方案作一概述。     

MicroRNA-182 is a potential biomarker for prognosis of gastric cancer: A protocol for meta-analysis and bioinformatics analysis

Background:Being the second leading cause of cancer death in the world, gastric cancer is a common malignant tumor in digestive system. Most patients were diagnosed in advanced stage and had poor prognosis. In recent years, related studies have displayed that MicroRNA-182 (miRNA-182) can promote the proliferation, infiltration, metastasis and drug resistance of tumor cells, so it can be used as a new molecular marker for the early diagnosis, prognosis, and treatment of tumors. However, the expression and prognosis of miRNA-182 in gastric cancer are not clear. Therefore, this study conducted a meta-analysis to further clarify the relationship between the expression of miRNA-182 in gastric cancer and prognosis. In addition, a bioinformatics analysis was adopted to further analyze the possible molecular mechanism of miRNA-182, so as to provide a theoretical basis for the diagnosis, treatment, and prognosis of patients suffering from gastric cancer.Methods:The following electronic databases were searched on computer: Wanfang, Chinese Biomedical Literature Database, Chinese National Knowledge Infrastructure, the Chongqing VIP Chinese Science and Technology Periodical Database, PubMed, Embase, and Web of Science databases. The retrieval time is set to build the database until April 2021. Combined hazard ratios (HRs) and 95% confidence intervals (95% CIs) were used to evaluate the effects of miRNA-182 on the prognosis of gastric cancer. Stata 16.0 software was applied for the meta-analysis. The expression of miRNA-182 in gastric cancer was analyzed by Gene Expression Omnibus database and The Cancer Genome Atlas database. The survival curve of miRNA-182 differential expression was analyzed by OncomiR. The target genes of miRNA-182 were predicted by TargetScan, miRBase, miRTarBase, starBase V2.0, and miRWalk. The target genes were obtained by the intersection of Wayne diagram. DAVID database was used for gene ontology (GO) and Kyoto encyclopedia of genes and genomes enrichment analysis. STRING database and Cytoscape were applied to construct Protein-protein interaction network to obtain key genes (hub gene). The expression of hub gene in gastric cancer was analyzed by gene expression profiling interactive analysis. The survival curve between hub gene and prognosis of gastric cancer was drawn by Kaplan-Meier Plotter database. TIMER database was used to analyze the relationship between hub gene expression and immune cell infiltration in gastric cancer.Results:The results of this meta-analysis will be submitted to a peer-reviewed journal for publication.Conclusion:This study provides high-quality evidence support for the expression of miRNA-182 and the prognosis of gastric cancer. Through bioinformatics analysis, we further discussed the mechanism of miRNA-182 in gastric cancer and the understanding of related pathways.OSF Registration Number:DOI 10.17605/OSF.IO/EHJ6X.     

A red meat-derived glycan promotes inflammation and cancer progression

A well known, epidemiologically reproducible risk factor for human carcinomas is the long-term consumption of “red meat” of mammalian origin. Although multiple theories have attempted to explain this human-specific association, none have been conclusively proven. We used an improved method to survey common foods for free and glycosidically bound forms of the nonhuman sialic acid N-glycolylneuraminic acid (Neu5Gc), showing that it is highly and selectively enriched in red meat. The bound form of Neu5Gc is bioavailable, undergoing metabolic incorporation into human tissues, despite being a foreign antigen. Interactions of this antigen with circulating anti-Neu5Gc antibodies could potentially incite inflammation. Indeed, when human-like Neu5Gc-deficient mice were fed bioavailable Neu5Gc and challenged with anti-Neu5Gc antibodies, they developed evidence of systemic inflammation. Such mice are already prone to develop occasional tumors of the liver, an organ that can incorporate dietary Neu5Gc. Neu5Gc-deficient mice immunized against Neu5Gc and fed bioavailable Neu5Gc developed a much higher incidence of hepatocellular carcinomas, with evidence of Neu5Gc accumulation. Taken together, our data provide an unusual mechanistic explanation for the epidemiological association between red meat consumption and carcinoma risk. This mechanism might also contribute to other chronic inflammatory processes epidemiologically associated with red meat consumption.There is a long-standing epidemiological link between the consumption of red meat (beef, pork, and lamb) and the incidence of carcinomas, atherosclerosis, type 2 diabetes, and all-cause mortality (1–4). Although such diseases have multifactorial origins, all are aggravated by chronic inflammation (5, 6). Red meat-rich diets also correlate with circulating markers of inflammation and endothelial dysfunction (7). Here, we focus on red meat-related risk of carcinomas (further citations regarding the association are provided in Table S1). Corroboration comes from the low rates of carcinomas in populations that consume very low levels or no red meat (8–10). Within the World Cancer Research Foundation report, red meat was among the top 10 factors associated with incidence and progression of carcinomas in all populations (11). Enhancement of carcinoma risk appears to be highest in tissues like colonic epithelium, in which adenomas can progress to carcinomas, driven by molecular changes in oncogenes and tumor suppressor genes (12). There are many proposed mechanisms for the cancer-promoting effects of red meat (13), including generation of mutagens by grilling, DNA damage due to N-nitroso compounds, or free radical generation by heme iron. However, none of these mechanisms have been proven, and confounding facts are apparent in some instances (e.g., grilling of poultry and fish generates the same mutagens, yet these foods are not associated with cancer risk) (14). Also, doses of the mutagens that induce carcinomas in animal models are many fold higher than human exposure (15). Overall, although more than one of these theories may still prove to be correct, definitive proof remains lacking.Another unexplained fact is the human specificity of this risk (i.e., other vertebrate carnivores do not suffer a high incidence of carcinomas). In this regard, we have suggested an unusual human-specific mechanism, involving inflammation associated with metabolic incorporation of a nonhuman sialic acid, N-glycolylneuraminic acid (Neu5Gc), and interaction with circulating anti-Neu5Gc antibodies (16–19). Despite the fact that humans are genetically unable to produce Neu5Gc, this molecule is detectable on surfaces of human epithelia and endothelia, and in higher amounts in malignant tissues (20). In the absence of an alternate pathway for Neu5Gc biosynthesis (21), the only possible source for incorporation is dietary intake (22). An initial food survey showed a prominent presence of Neu5Gc in red meat (23). Metabolic incorporation of dietary Neu5Gc into tissues (24) makes this glycan the first example, to our knowledge, of a xeno-autoantigen, which can react with circulating anti-Neu5Gc antibodies (i.e., xeno-autoantibodies) (25). The resulting antigen–antibody interaction is hypothesized to generate or promote chronic inflammation or “xenosialitis,” which could contribute to carcinogenesis or to other diseases exacerbated by chronic inflammation.Although attractive in principle, this hypothesis has not been proven in an in vivo system. Notably, Cmah^−/− (CMP-Neu5Ac hydroxylase knockout) mice with a human-like deficiency of Neu5Gc (24) can incorporate Neu5Gc of dietary origin, but only if provided in the bioavailable glycosidically bound form (22). However, such mice do not spontaneously generate anti-Neu5Gc antibodies. The likely reason is that humans are spontaneously immunized via an unusual postnatal process involving a human-specific commensal bacterium that presents Neu5Gc from weaning foods to the immune system (26). However, an anti-Neu5Gc response is induced in Cmah^−/− mice by active immunization, and specific antisera can be generated. Using such antisera in Cmah^−/− mice bearing syngeneic Cmah^+/+ tumors, we have shown that the anti-Neu5Gc antibodies could facilitate tumor progression by enhancing inflammation (16, 17). However, despite this suggestive evidence, we have not demonstrated that oral feeding of Neu5Gc can induce the proposed xenosialitis in vivo or that this process can increase rates of spontaneous carcinomas. Also, dietary surveys on Neu5Gc in food have been limited, the ratio of bound and free Neu5Gc has not been determined, and effects of food processing have not been considered. Given our hypothesis that tissue incorporation of Neu5Gc of dietary origin can have deleterious effects, it is important to determine the amounts present in typical components of the Western diet accurately. Although earlier studies attempted to quantify Neu5Gc distribution in food (23, 27–29), a systematic catalog of a wide variety of commonly consumed foods is lacking. Furthermore, based on recent studies (22), it appears that glycosidically bound Neu5Gc is the dietary source that is bioavailable for tissue incorporation, and not the free monosaccharide. However, available data neither differentiated between bound and free Neu5Gc nor addressed the effects of food processing.Here, we address all these issues by first developing an assay to determine amounts of free and bound Neu5Gc accurately in a wide variety of foods. We then evaluate the impact of short-term and long-term feeding of Neu5Gc in Cmah^−/− mice combined with passive or active immunization against Neu5Gc. Although the association between red meat consumption and colon cancer is most prominent in humans, we focus here on hepatocellular cancer in male C57BL/6 mice as proof of principle, because these animals have a low rate of spontaneously occurring hepatic tumors (30).     

浸润性乳腺癌组织中ADAMTS-4及ARGxx的表达变化

目的观察浸润性乳腺癌组织中含Ⅰ型血小板结合蛋白基序的解聚蛋白样金属蛋白酶-4（ADAMTS-4）及其裂解蛋白聚糖后产生的新抗原表位ARGxx的表达变化。方法选择浸润性乳腺癌手术切除标本20份（观察组）及乳腺纤维腺瘤手术切除标本22份（对照组）,采用免疫组化法检测其中的ADAMTS-4及ARGxx,并通过显微镜测量其表达强度（光密度值）。结果观察组和对照组ADAMTS-4表达阳性率分别为80.0%、27.3%,ARGxx表达阳性率分别为80.0%、18.2%,组间比较P均〈0.01;观察组和对照组ADAMTS-4光密度值分别为0.235 8±0.059 5、0.170 0±0.051 0,ARGxx光密度值分别为0.215 0±0.045 5、0.134 2±0.036 3,组间比较P均〈0.05。结论浸润性乳腺癌组织中ADAMTS-4表达升高且活性显著增强。     

Combining CD47 blockade with trastuzumab eliminates HER2-positive breast cancer cells and overcomes trastuzumab tolerance

Trastuzumab, a targeted anti-human epidermal-growth-factor receptor-2 (HER2) monoclonal antibody, represents a mainstay in the treatment of HER2-positive (HER2⁺) breast cancer. Although trastuzumab treatment is highly efficacious for early-stage HER2⁺ breast cancer, the majority of advanced-stage HER2⁺ breast cancer patients who initially respond to trastuzumab acquire resistance to treatment and relapse, despite persistence of HER2 gene amplification/overexpression. Here, we sought to leverage HER2 overexpression to engage antibody-dependent cellular phagocytosis (ADCP) through a combination of trastuzumab and anti-CD47 macrophage checkpoint immunotherapy. We have previously shown that blockade of CD47, a surface protein expressed by many malignancies (including HER2⁺ breast cancer), is an effective anticancer therapy. CD47 functions as a “don’t eat me” signal through its interaction with signal regulatory protein-α (SIRPα) on macrophages to inhibit phagocytosis. Hu5F9-G4 (magrolimab), a humanized monoclonal antibody against CD47, blocks CD47’s “don’t eat me” signal, thereby facilitating macrophage-mediated phagocytosis. Preclinical studies have shown that combining Hu5F9-G4 with tumor-targeting antibodies, such as rituximab, further enhances Hu5F9-G4’s anticancer effects via ADCP. Clinical trials have additionally demonstrated that Hu5F9-G4, in combination with rituximab, produced objective responses in patients whose diffuse large B cell lymphomas had developed resistance to rituximab and chemotherapy. These studies led us to hypothesize that combining Hu5F9-G4 with trastuzumab would produce an anticancer effect in antibody-dependent cellular cytotoxicity (ADCC)-tolerant HER2⁺ breast cancer. This combination significantly suppressed the growth of ADCC-tolerant HER2⁺ breast cancers via Fc-dependent ADCP. Our study demonstrates that combining trastuzumab and Hu5F9-G4 represents a potential new treatment option for HER2⁺ breast cancer patients, even for patients whose tumors have progressed after trastuzumab.

Overexpression of human epidermal-growth-factor receptor-2 (HER2) occurs in ∼16% of breast cancers in the United States (1–3) and has been associated with a number of adverse prognostic factors (summarized in ref. 4). Prior to the advent of HER2-targeted therapeutics, HER2 overexpression was associated with increased risk of recurrence and poor survival rates (1, 2). Trastuzumab is a humanized monoclonal antibody that selectively binds HER2. Clinical use of trastuzumab has dramatically improved the outcomes of patients with HER2⁺ breast cancer and remains the foundational component of modern standard of care treatment regimens for HER2⁺ breast cancer in the neoadjuvant, adjuvant, and metastatic settings (5, 6). Early studies of trastuzumab’s mechanism of action focused on trastuzumab’s inhibition of protumor growth HER2 signaling pathways (7–9). Subsequent research revealed that trastuzumab also coopts a patient’s immune system to promote an antitumor response (7–11). This later body of research initially elucidated trastuzumab’s ability to engage Fc-receptors on natural killer cells (NKs) to promote antibody-dependent cellular cytotoxicity (ADCC) (12, 13). Recent reports have further illuminated trastuzumab’s ability to engage Fc-γ receptors (FcγR) on macrophages and promote antibody-dependent cellular phagocytosis (ADCP) (14).Administering trastuzumab to early-stage HER2⁺ breast cancer patients significantly increases disease-free survival and overall survival rates (15–17). Treating advanced-stage HER2⁺ breast cancer patients with the most efficacious trastuzumab-based regimens, however, produces less hopeful outcomes. For example, the Food and Drug Administration (FDA)-approved regimen studied in the CLEOPATRA clinical trial for HER2⁺ metastatic breast cancer in the first line of treatment utilized trastuzumab in combination with docetaxel and pertuzumab; this regimen resulted in a median progression-free survival of 18.7 mo (18, 19). In the same study, 19.8% of patients did not achieve an objective clinical response to trastuzumab-based treatment (20). And, of the advanced-stage HER2⁺ breast cancer patients who initially responded to trastuzumab, pertuzumab, and docetaxel, the median duration of response was 20.2 mo; thereafter, the majority of patients experienced objective disease-progression, defining acquired clinical resistance to trastuzumab-based therapy (18).A myriad of potential mechanisms of trastuzumab resistance have been reported, such as: 1) perturbation of HER family receptors or binding of therapeutic antibodies to HER2 (e.g., shedding of the HER2 extracellular domain, expression of the Δ16HER2 splice isoform, overexpression of MUC4/MUC1 resulting in steric hindrance to trastuzumab binding to the HER2 extracellular domain, and increased phosphorylation of HER3); 2) parallel receptor pathway activation (e.g., overexpression of other HER family members, up-regulation of IGF1 receptor, erythropoietin receptor, AXL receptor, or MET receptor); and 3) activation of downstream signaling events distal to HER2 receptor (e.g., hyperactivation of the PI3 kinase/Akt pathway by loss of PTEN or PIK3CA mutational activation, cyclin E amplification/overexpression, up-regulation of miR-21, and expression of the estrogen receptor) (21). Impairments in trastuzumab-mediated ADCC may also lead to relative resistance to trastuzumab (22, 23). Interestingly, it has been shown that even after HER2⁺ breast cancers relapse or progress after trastuzumab, resistant cells most often still overexpress HER2 (24). Given the many ways in which trastuzumab resistance develops, there is an urgent clinical need for novel treatment approaches that provide HER2 specificity without eliciting the same mechanisms of trastuzumab resistance that are currently seen in the clinic (25). This led us to hypothesize that engagement of macrophages and activation of ADCP could still be effective even in the face of various resistance mechanisms—as long as the HER2 ectodomain target epitope is present.Our laboratory has previously shown that many different cancers overexpress the CD47 surface protein to convey a “don’t eat me” signal to macrophages (26–29) and to counteract “eat me” signals (30–32), thereby resulting in immune evasion through inhibition of macrophage phagocytosis. This led to the development of a new type of immunotherapy based on macrophage checkpoint inhibition through blockade of CD47. Hu5F9-G4 (magrolimab) is a humanized monoclonal antibody against CD47 that blocks CD47''s interaction with signal regulatory protein-α (SIRPα), thereby diminishing the inhibition of macrophages by cancer cells (33). As a monotherapy, Hu5F9-G4’s anticancer activity works by blocking CD47’s antiphagocytic signaling. The combination of Hu5F9-G4 and tumor-targeting antibodies, moreover, promotes ADCP by increasing the amount of “eat me” signals provided by the interaction of cancer-targeting antibody Fc domains and macrophage Fc-receptors (33–36). We have previously demonstrated this principle of ADCP enhancement in the context of rituximab-resistant CD20-expressing diffuse large B cell non-Hodgkin’s lymphoma. These studies showed that combining Hu5F9-G4 with rituximab (an anti-CD20 tumor-targeting antibody) in human xenograft models produced an anticancer ADCP response (34). In the clinical trials that followed, about half of the patients who are relapsed and refractory to rituximab plus or minus chemotherapy nevertheless responded to magrolimab plus rituximab (35). This clinical study suggested that combining Hu5F9-G4 with rituximab may resensitize refractory lymphoma cells to rituximab via an ADCP mechanism (35, 37).Based on these previous studies, we hypothesized that administering a combination of trastuzumab and Hu5F9-G4 to ADCC-tolerant HER2⁺ breast cancer cells would resensitize these cells to trastuzumab. We found that this combination was more efficacious than either treatment alone. We also found that this combinatorial treatment augments ADCP via Fc-receptor-mediated phagocytosis. Taken together, our study suggests that combining Hu5F9-G4 and trastuzumab may represent an alternative or complementary approach to the current standard of care for advanced HER2⁺ breast cancer that expands trastuzumab’s efficacy through engaging ADCP while preserving and utilizing trastuzumab’s HER2-targeting capabilities.     

Obesity and breast cancer screening

BACKGROUND: Compared to normal weight women, women with obesity have higher mortality from breast cancer but are less often screened. OBJECTIVES: To examine the relation between mammography use and weight category and to examine the influence of race, illness burden, and other factors on this relationship. DESIGN AND SETTING: The 1998 National Health Interview Survey, a U.S. civilian population-based survey. PARTICIPANTS: Five thousand, two hundred, and seventy-seven women ages 50 to 75 years who responded to the Sample Adult and Prevention questionnaires. MEASUREMENTS: Mammogram use in the preceding 2 years. RESULTS: Among 5277 eligible women, 72% reported mammography use. The rate was 74% among white women and 70% among black women. Among white women, mammogram use was lowest in women with a body mass index (BMI) greater than 35 kg/m(2) (64% to 67%). After adjusting for sociodemographic factors, health care access, medical conditions, hospitalizations, and mobility status, higher BMI was associated with lower screening among white women, P =.02 for trend; the relative risk (RR) for screening in moderately obese white women (BMI, 35 to 40 kg/m(2)) was 0.83 (95% confidence interval [CI], 0.68 to 0.96) compared to normal weight white women. Compared to normal weight black women, mammography use was similar or higher in overweight (BMI, 25 to 30 kg/m(2); RR, 1.19; 95% CI, 1.01 to 1.32), mildly obese (BMI, 30 to 35 kg/m(2); RR, 1.22; 95% CI, 0.98 to 1.39), and moderately obese black women (RR, 1.37; 95% CI, 1.37 to 1.50) after adjustment. The P value for the race-BMI interaction was.001. Results for white and black women were unchanged after additional adjustment for psychological functioning and health habits. CONCLUSION: Among white women, those with higher BMI were less likely to undergo breast cancer screening than normal weight women. This relationship was not seen in black women. Our findings were not explained by differences in sociodemographic factors, health care access, illness burden, or health habits. More research is needed to determine the reasons for these disparities so that appropriate efforts can be made to improve screening.     

Baicalin suppresses the migration and invasion of breast cancer cells via the TGF-β/lncRNA-MALAT1/miR-200c signaling pathway

Metastasis is the major cause of death and failure of cancer chemotherapy in patients with breast cancer (BC). Activation of TGF-β/lncRNA-MALAT1/miR-200c has been reported to play an essential role during the metastasis of BC cells. The present study aimed to validate the suppression of BC-cell migration and invasion by baicalin and explore its regulatory effects on the TGF-β/lncRNA-MALAT1/miR-200c signaling pathway. We found that baicalin treatment inhibited cell viability and migration and invasion. Mechanistically, baicalin treatment significantly downregulated the expression of TGF-β, ZEB1, and N-cadherin and upregulated E-cadherin on both mRNA and protein levels. Additionally, baicalin treatment significantly downregulated the expression of lncRNA-MALAT1 and upregulated that of miR-200c. Collectively, baicalin significantly suppresses cell viability, migration, and invasion of BC cells possibly by regulating the TGF-β/lncRNA-MALAT1/miR-200c pathway.