Chronic pulmonary bacterial infection facilitates breast cancer lung metastasis by recruiting tumor-promoting MHCIIhi neutrophils

Background: The metastasis of breast cancer is the leading cause of death, while lung metastasis is a major clinical phenomenon in patients with invasive breast cancer. The current treatment option comprising surgery, radiation, and standard chemotherapy cannot achieve a satisfactory effect on the treatment of lung metastasis of breast cancer. In this study, we report the potential of preventing lung metastasis of invasive breast cancer using the newly developed functional vincristine plus dasatinib liposomes. Methods: The investigations were performed on invasive breast cancer MDA-MB-231 cells in vitro and in lung metastatic model of invasive breast cancer MDA-MB-231 cells in nude mice. Results: The functional drug liposomes were able to induce cell cycle arrest at G2/M phase, induce apoptosis, inhibit adhesion, migration, and invasion of breast cancer cells in vitro, and prevent lung metastasis of breast cancer in nude mice. Conclusion: These findings indicate a potential clinical use of functional vincristine plus dasatinib liposomes for treating metastatic breast cancer.

We report 3 cases of surgical resection for lung metastasis more than 15 years after initial surgery for breast cancer. Case 1: A 77-year-old woman was referred to our hospital because of a lung nodule in the left lower lobe detected in a computed tomography (CT) scan. She had undergone breast preservation therapy for breast cancer 15 years before the first visit. Left lower lobectomy was performed via video-assisted thoracoscopic surgery (VATS). The pathological diagnosis was lung metastasis of breast cancer, based on positive immunohistochemical staining of estrogen receptor (ER) and gross cystic disease fluid protein 15 (GCDFP-15). Case 2: An 88-year-old woman had undergone a mastectomy for breast cancer 23 years previously. A CT scan revealed a nodule in the upper lobe of the left lung. A wedge resection of the left upper lobe was performed. Because immunostainings for progesterone receptor (PgR) and GCDFP-15 were positive, the pathological diagnosis was metastasis of breast cancer. Case 3: A 78-year-old woman had undergone right mastectomy for the breast cancer 29 years previously. The patient was referred to our hospital because of a nodule in the right lung in a CT scan. Thoracoscopic right upper lobectomy was performed. The pathological diagnosis was lung metastasis of the breast cancer, with immunohistochemical positivity to ER, PgR, and focally to GCDFP-15. A differential diagnosis between primary lung cancer and metastasis of breast cancer on the basis of the findings of a CT scan is often difficult. It is important to obtain the previous clinical information about the breast cancer before VATS, even in patients with a long disease-free interval of more than 15 years.

The role of neutrophils in tumor metastasis has recently attracted widespread interest. Neutrophils are the most abundant immune cells in human peripheral blood, and large numbers can spontaneously migrate to metastatic sites, where they form an immunosuppressive microenvironment. Polysialic acid (PSA) can target peripheral blood neutrophils (PBNs) mediated by L-selectin, and abemaciclib (ABE) and mitoxantrone (MIT) can treat immunosuppressive microenvironments. Here, we aimed to inhibit lung metastasis of breast cancer and improve chemoimmunotherapy by designing a PSA-modified ABE and MIT co-delivery system (AM-polyion complex (PIC)) to target PBNs in mice with metastatic tumors. We found that through electrostatic interactions between the strong negative charge of PSA and the positive charge of the drug can form stable nanocomplexes and that spontaneous migration of neutrophils can mediate the aggregation of these complexes in the lungs, induce antimetastatic immune responses, enhance the effectiveness of cytotoxic T lymphocytes (CTLs), and inhibit regulatory T cell (Treg) proliferation in vivo and in vitro. Pharmacodynamic results suggested that neutrophil-mediated AM-PIC chemoimmunotherapy inhibited tumor metastasis in mice with lung metastasis of 4T1 breast cancer. Overall, PSA-modified nanocomplexes offer promising neutrophil-mediated, targeted drug delivery systems to treat lung metastasis of breast cancer.

BackgroundThe relationship between cytokines and lung metastasis (LM) in breast cancer (BC) remains unclear and current clinical methods for identifying breast cancer lung metastasis (BCLM) lack precision, thus underscoring the need for an accurate risk prediction model. This study aimed to apply machine learning algorithms for identifying the key risk factors for BCLM before developing a reliable prediction model centered on cytokines.MethodsThis population-based retrospective study included 326 BC patients admitted to the Second Affiliated Hospital of Xuzhou Medical University between September 2018 and September 2023. After randomly assigning the patients to a training cohort (70%; n = 228) or a validation cohort (30%; n = 98) the risk factors for BCLM were identified using Least Absolute Shrinkage and Selection Operator (LASSO), Extreme Gradient Boosting (XGBoost) and Random Forest (RF) models. Significant risk factors were visualized with a Venn diagram and incorporated into a nomogram model, the performance of which was then evaluated according to three criteria, namely discrimination, calibration and clinical utility using calibration plots, receiver operating characteristic (ROC) curves and decision curve analysis (DCA).ResultsAmong the cohort, 70 patients developed LM. A nomogram was then developed to predict the 5-year and 10-year BCLM risk by incorporating five key variables, namely endocrine therapy, hsCRP, IL6, IFN-ɑ and TNF-ɑ. For the 5-year prediction model, the training and validation cohorts had AUC values of 0.786 (95% CI: 0.691–0.881) and 0.627 (95% CI: 0.441–0.813), respectively, while for the 10-year prediction model, the corresponding AUC values were 0.687 (95% CI: 0.528–0.847) and 0.797 (95% CI: 0.605–0.988), respectively. ROC analysis further confirmed the model’s strong discriminative ability, while calibration plots indicated that the predicted and observed outcomes were in good agreement in both cohorts. Finally, DCA demonstrated the model’s effectiveness in clinical practice.ConclusionUsing machine learning algorithms, this study developed aa nomogram that could effectively identify BC patients who were at a higher risk of developing LM, thus providing a valuable tool for decision-making in clinical settings.

Hydrophobic interaction mediating self-assembled nanoparticles of succinobucol suppress lung metastasis of breast cancer by inhibition of VCAM-1 expression

Breast cancer (BC) is an aggressive cancer with a high percentage recurrence and metastasis. As one of the most common distant metastasis organ in BC, lung metastasis has a worse prognosis than that of liver and bone. Therefore, it's important to explore some potential prognostic markers associated with the lung metastasis in BC for preventive treatment. In this study, transcriptomic data and clinical information of BC patients were downloaded from The Cancer Genome Atlas (TCGA) database. Co-expression modules constructed by weighted gene co-expression network analysis (WGCNA) found the royal blue module was significantly associated with lung metastasis in BC. Then, co-expression genes of this module were analyzed for functional enrichment. Furthermore, the prognostic value of these genes was assessed by GEPIA Database and Kaplan-Meier Plotter. Results showed that the hub genes, LMNB and CDC20, were up-regulated in BC and had a worse survival of the patients. Therefore, we speculate that these two genes play crucial roles in the process of lung metastasis in BC, which can be used as potential prognostic markers in lung metastasis of BC. Collectively, our study identified two potential key genes in the lung metastasis of BC, which might be applied as the prognostic markers of the precise treatment in breast cancer with lung metastasis.

Pigment epithelium-derived factor (PEDF) plays an important role in the tumor growth and metastasis inhibition. It has been reported that PEDF expression is significantly reduced in breast cancer, and associated with disease progression and poor patient outcome. However, the exact mechanism of PEDF on breast cancer metastasis including liver and lung metastasis remains unclear. The present study aims to reveal the impact of PEDF on breast cancer. The orthotopic tumor mice model inoculated by MDA-MB-231 cells stably expressing PEDF or control cells was used to assess liver and lung metastasis of breast cancer. In vitro, migration and invasion experiments were used to detect the metastatic abilities of MDA-MB-231 and SKBR3 breast cancer cells with or without overexpression of PEDF. The metastatic-related molecules including EMT makers, fibronectin, and p-AKT and p-ERK were detected by qRT-PCR, Western blot, and Fluorescent immunocytochemistry. PEDF significantly inhibited breast cancer growth and metastasis in vivo and in vitro. Mechanically, PEDF inhibited breast cancer cell migration and invasion by down-regulating fibronectin and subsequent MMP2/MMP9 reduction via p-ERK and p-AKT signaling pathways. However, PEDF had no effect on EMT conversion in the breast cancer cells which was usually involved in cancer metastasis. Furthermore, the study showed that laminin receptor mediated the down-regulation of fibronectin by PEDF. These results reported for the first time that PEDF inhibited breast cancer metastasis by down-regulating fibronectin via laminin receptor/AKT/ERK pathway. Our findings demonstrated PEDF as a dual effector in limiting breast cancer growth and metastasis and highlighted a new avenue to block breast cancer progression.

High delivery efficiency, prolonged drug release, and low systemic toxicity are effective weapons for drug delivery systems to win the battle against metastatic breast cancer. Herein, it is shown that Spirulina platensis (S. platensis) can be used as natural carriers to construct a drug-loaded system for targeted delivery and fluorescence imaging-guided chemotherapy on lung metastasis of breast cancer. The chemotherapeutic doxorubicin (DOX) is loaded into S. platensis (SP) via only one facile step to fabricate the DOX-loaded SP (SP@DOX), which exhibits ultrahigh drug loading efficiency and PH-responsive drug sustained release. The rich chlorophyll endows SP@DOX excellent fluorescence imaging capability for noninvasive tracking and real-time monitoring in vivo. Moreover, the micrometer-sized and spiral-shaped SP carriers enable the as-prepared SP@DOX to passively target the lungs and result in a significantly enhanced therapeutic efficacy on lung metastasis of 4T1 breast cancer. Finally, the undelivered carriers can be biodegraded through renal clearance without notable toxicity. The SP@DOX described here presents a novel biohybrid strategy for targeted drug delivery and effective treatment on cancer metastasis.

The essential action of B7 homolog 3 (B7-H3) in different diseases and cancers has been documented. We here focused on its role in breast cancer through the Raf/MEK/ERK axis regarding lung metastasis. Expression pattern of B7-H3 was determined in breast cancer tissues and cells with its correlation with prognosis analyzed. Then, through transfection of lentivirus vector expressing B7-H3-shRNA, overexpression vector of B7-H3 (B7-H3-LV), U0126 (small molecule inhibitor of MEK), or PD98059 (small molecule inhibitor of ERK), the in vitro and in vivo effects of B7-H3 in breast cancer cell biological processes, and lung metastasis were analyzed in relation to the Raf/MEK/ERK axis. We discovered elevated B7-H3 in breast cancer and its elevation associated with poor prognosis. B7-H3 promoted the malignant properties of breast cancer cells, accompanied with increased N-cadherin and vimentin and reduced E-cadherin. Additionally, overexpression of B7-H3 accelerated the lung metastasis in breast cancer in vivo. All the above promoting action of B7-H3 was achieved through activation of the Raf/MEK/ERK signaling pathway. Taken together, B7-H3 can promote lung metastasis in breast cancer through activation of the Raf/MEK/ERK axis.

Prognostic factors analysis and nomogram construction of breast cancer patients lung metastases and bone metastases.

In Breast cancer, Lung is the second most common site of metastasis after the bone. Various factors are responsible for Lung metastasis occurring secondary to Breast cancer. Cancer cell-derived secretory factors are commonly known as ‘Cancer Secretomes’. They exhibit a prompt role in the mechanism of Breast cancer lung metastasis. They are also major constituents of host-associated tumor microenvironment. Through cross-talk between cancer cells and the extracellular matrix components, cancer cell-derived extracellular matrix components (CCECs) such as hyaluronan, collagens, laminin and fibronectin cause ECM remodeling at the primary site (breast) of cancer. However, at the secondary site (lung), tenascin C, periostin and lysyl oxidase, along with pro-metastatic molecules Coco and GALNT14, contribute to the formation of pre-metastatic niche (PMN) by promoting ECM remodeling and lung metastatic cells colonization. Cancer cell-derived secretory factors by inducing cancer cell proliferation at the primary site, their invasion through the tissues and vessels and early colonization of metastatic cells in the PMN, potentiate the mechanism of Lung metastasis in Breast cancer.On the basis of biochemical structure, these secretory factors are broadly classified into proteins and non-proteins. This is the first review that has highlighted the role of cancer cell-derived secretory factors in Breast cancer Lung metastasis (BCLM). It also enumerates various researches that have been conducted to date in breast cancer cell lines and animal models that depict the prompt role of various types of cancer cell-derived secretory factors involved in the process of Breast cancer lung metastasis. In the future, by therapeutically targeting these cancer driven molecules, this specific type of organ-tropic metastasis in breast cancer can be successfully treated.

Mental stress is widely recognized as a significant risk factor for breast cancer, exerting detrimental effects on both progression and prognosis. Herein, we investigated the role of stress in regulating breast cancer metastasis. In genetically engineered and transplantation breast cancer mouse models, chronic stress stimulation increased tumor growth and lung metastasis. Single-cell RNA-sequencing analysis of the pre-metastatic lung microenvironment revealed induction of a previously unrecognized subtype of cancer stress-primed (CSP) neutrophils, characterized by the overexpression of Ccl3, Ccl4, Cxcl2, Il1r2, and Cebpb. Pseudotime trajectory analysis demonstrated that chronic stress caused a shift of neutrophils from the cancer-primed (CP) neutrophil subtype to the CSP subtype in the lung. Activation of the glucocorticoid receptor NR3C1 by the stress hormone corticosterone induced expression of Cebpb in neutrophils, which then promoted transcription of Ccl3 and Ccl4. The differentiation of neutrophils into the CSP subtype promoted lung metastasis of CCR1+ breast cancer cells via CCL3/CCL4-mediated recruitment. Targeting this axis using an anti-Ly6G antibody to deplete neutrophils, a CRISPR/Cas9-mediated approach to conditionally knockout Ccl3/Ccl4 in neutrophils, and BX471 treatment to inhibit CCR1 in cancer cells all significantly reduced breast cancer lung metastasis. Together, this study not only demonstrates a stress-neutrophil-cancer axis that promotes lung metastasis in breast cancer but also provides potential strategies for reducing lung metastasis by targeting CSP neutrophils or CCR1+ breast cancer cells.

Dexamethasone (Dex), as a pretreatment agent, is widely used to attenuate the side effects of chemotherapy in breast cancer treatment. However, whether and how Dex affects breast cancer metastasis remain to be furtherly understood. In this study, we established several mouse breast cancer metastatic models to study the effect of Dex in vitro and in vivo. Transwell, Western Blot and RNA interference were applied to study the molecular mechanism of Dex in promoting breast cancer cell migration. Meanwhile, the effect of Dex on lung metastasis of breast cancer in Dex combined with PTX chemotherapy was discussed. Our results confirmed that Dex could promote breast cancer cell metastasis both in vitro and in vivo. Mechanistic studies revealed that this pro-metastatic effect of Dex was mediated by the GR-PI3K-SGK1-CTGF pathway in tumor cells. Ligation of Dex and glucocorticoid receptor (GR) on tumor cells activated the PI3K signaling pathway and upregulated serum glucocorticoid-inducible kinase 1 (SGK1) expression, and then increased the expression of connective tissue growth factor (CTGF) through Nedd4l-Smad2. Moreover, Dex was the leading factor for lung metastasis in a standard regimen for breast cancer treatment with paclitaxel and Dex. Importantly, targeting SGK1 with the inhibitor GSK650394 remarkably reduced lung metastasis in this regimen. Our present data provide new insights into Dex-induced breast cancer metastasis and indicate that SGK1 could be a candidate target for the treatment of breast cancer metastasis.

Metastasis is the main cause of patient death among many tumor types including breast cancer and breast cancer patients with obesity have higher risk of distant metastases during 10-year follow-up. Diet is one of the main and manageable factors that cause obesity and regular intake of high-fat diets can induce obesity. In addition, fibroblasts, as the most abundant stromal cell type in tumor microenvironment, are involved in cancer metastasis. However, the role of fibroblasts and the downstream mechanism in metastasis of patients with high-fat diet remains unclear. In this study, we fed MMTV-PyMT transgenic mice with high-fat diet to obtain a high-fat tumorigenesis model, and isolate primary lung fibroblasts and then coculture them with breast cancer cells to explore the interaction. We found that a high-fat diet can significantly promote progression of primary breast cancer and lung metastasis, and that before weight difference shows, there is a different chemotactic influence of lung fibroblasts on breast cancer cell between high-fat diet and normal diet group. And we observed increased chemotactic function of primary lung fibroblasts in high-fat diet group. Moreover, tumor cells treated with primary lung fibroblasts in high-fat diet group show increased ability of adhesion, suggesting that high-fat diet chemoattracts breast cancer cell colonization by activating lung fibroblasts. Collectively, we explored the functional differences of lung fibroblast and the key factors for the lung colonization of recruited breast cancer cells. Our findings suggest that dietary patterns are associated with the risk of breast cancer metastasis and targeting activated fibroblasts in pre-metastatic microenvironment may serve as potential early therapeutic strategy to reduce breast cancer lung metastasis. Citation Format: Huiping Chen, Penghan Huang, Jianing Chen, Erwei Song. High-fat diets promote lung metastasis of breast cancer by activating lung fibroblasts [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6123.

Breast cancer is the most commonly diagnosed non-cutaneous cancer in American women and is estimated to cause 40,000 deaths this year. Despite standard of care, breast cancer patients often relapse after a few years of treatment thus highlighting the need for new molecular targets for improved management of metastatic disease. Abelson interactor 1 (Abi1) is an adaptor protein associated with the WAVE (Wiscott-Aldrich syndrome protein family verprolin homologous) regulatory complex and Arp2/3 (Actin-related proteins 2 and 3)-mediated actin cytoskeleton remodeling. Our analysis of human tumor data indicates that Abi1 is frequently upregulated in invasive breast cancers, is associated with poor survival, and may promote an aggressive breast tumor phenotype. Abi1 has been shown to positively regulate breast cancer cell proliferation, motility, division, and invasion in vitro however its exact role in vivo remains unknown. We therefore hypothesize that Abi1 promotes breast tumor progression and metastasis in a mouse breast cancer model. Using the well-characterized Polyoma Middle T (PyMT) breast cancer model, we conditionally deleted Abi1 from the mammary epithelium and determined the effects on tumor growth kinetics and WAVE complex protein levels. Interestingly, our studies show delayed tumor growth only in mice with heterozygous deletion of Abi1 while homozygote KO mice show relatively unchanged tumor growth. Western blot analyses of Abi1 KO breast tumors show concomitant loss of WAVE complex proteins supporting our previous findings that WAVE complex integrity is dependent on Abi1. Our data also show significant upregulation of Abi2 only in homozygous Abi1 KO mice, suggesting a potential compensatory role for Abi2 that may support primary tumor growth in absence of Abi1. Most interestingly, Abi1 null PyMT mice show significantly reduced incidence of lung metastasis, supporting our hypothesis that Abi1 promotes metastasis of breast cancer cells. In summary, Abi1 loss abrogates lung metastasis in PyMT mice however primary tumor growth remains largely unaffected, possibly due to a compensatory mechanism by a related protein, Abi2. This work will establish the biochemical dynamics between members of the Abi protein family and WAVE complex to improve targeted treatments in aggressive human breast cancer. [Supported by NCI grant R01-CA161018 and Carol M. Baldwin Breast Cancer Research Fund of CNY] Citation Format: Angelina Regua, Isabelle Bichindaritz, Tiffany Caza, Julie R. White, Alexander Nappi, Claudia Mondragon, Mira Krendel, Gennady Bratslavsky, Abirami Sivapiragasam, Leszek Kotula. Abi1 positively regulates lung metastasis of aggressive breast cancer in PyMT mouse model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 108.