Strategy For Treatment Of Breast Cancer Research Articles

In Vitro and In Vivo Comparative Analysis of Differentially Expressed Genes and Signaling Pathways in Breast Cancer Cells on Interaction with Mesenchymal Stem Cells.

The interaction of breast cancer cells (BCC) with mesenchymal stem cells (MSC) plays a vital role in influencing the gene expression in breast cancer cells and thereby its uncontrolled proliferation, metastasis, and drug resistance. The extent of MSC governing the BCC or the extent of BCC influencing the MSC is a complex process, and the interaction strongly depends upon conditions such as the presence or absence of other cell types and in vivo tumor microenvironment or simple in vitro conditions. Hence, understanding this interaction through gene expression profiling may provide key insights about potential genes which can be targeted for breast cancer treatment. In the current study, in vitro microarray dataset and in vivo RNA-seq dataset of BCC on interaction with the MSC were downloaded from NCBI GEO database and analyzed for differentially expressed genes (DEGs), gene ontology (GO) term enrichment, and Reactome pathway analysis. To target the genes which have similar effect on both in vitro and in vivo, a comparative analysis was performed, 24 genes were commonly upregulated in both in vitro and in vivo datasets, while no common downregulated genes were observed. Out of which, 16 significant genes based upon fold change (logFC > 2) are identified for manipulating the interactions between MSC and BCC. Among them, 6 of the identified genes (FSTL1, LOX, SERPINE1, INHBA, FN1, and VEGFA) have already been reported to be upregulated in BCC on interaction with MSC by various studies. Further experiments need to be conducted to understand the role of remaining 10 identified genes (EFEMP1, IGFBP3, EDIL3, IFITM1, IGFBP4, ITGA5, SLC3A2, HRH1, PPP1R15A, and NNMT) in MSC-BCC interaction. In addition to the reported significant genes and its associated pathways, the expression of long non-coding RNA identified in this study may increase our understanding about the way MSC interacts with BCC and accelerate MSC-based treatment strategies for breast cancer.

Breast cancer: an up-to-date review and future perspectives.

Breast cancer is the most common cancer worldwide. The occurrence of breast cancer is associated with many risk factors, including genetic and hereditary predisposition. Breast cancers are highly heterogeneous. Treatment strategies for breast cancer vary by molecular features, including activation of human epidermal growth factor receptor 2 (HER2), hormonal receptors (estrogen receptor [ER] and progesterone receptor [PR]), gene mutations (e.g., mutations of breast cancer 1/2 [BRCA1/2] and phosphatidylinositol‐4,5‐bisphosphate 3‐kinase catalytic subunit alpha [PIK3CA]) and markers of the immune microenvironment (e.g., tumor‐infiltrating lymphocyte [TIL] and programmed death‐ligand 1 [PD‐L1]). Early‐stage breast cancer is considered curable, for which local‐regional therapies (surgery and radiotherapy) are the cornerstone, with systemic therapy given before or after surgery when necessary. Preoperative or neoadjuvant therapy, including targeted drugs or immune checkpoint inhibitors, has become the standard of care for most early‐stage HER2‐positive and triple‐negative breast cancer, followed by risk‐adapted post‐surgical strategies. For ER‐positive early breast cancer, endocrine therapy for 5‐10 years is essential. Advanced breast cancer with distant metastases is currently considered incurable. Systemic therapies in this setting include endocrine therapy with targeted agents, such as CDK4/6 inhibitors and phosphoinositide 3‐kinase (PI3K) inhibitors for hormone receptor‐positive disease, anti‐HER2 targeted therapy for HER2‐positive disease, poly(ADP‐ribose) polymerase inhibitors for BRCA1/2 mutation carriers and immunotherapy currently for part of triple‐negative disease. Innovation technologies of precision medicine may guide individualized treatment escalation or de‐escalation in the future. In this review, we summarized the latest scientific information and discussed the future perspectives on breast cancer.

Optimization Method of an Antibreast Cancer Drug Candidate Based on Machine Learning.

Breast cancer is a common but serious and even lethal disease. Fortunately, compared with other cancers, breast cancer treatments currently are relatively well developed. The use of specific drugs is typically essential in the majority of breast cancer treatment strategies. Given the aforementioned factors, it is important to continue researching effective antibreast cancer drug design. Machine learning-based computer-aided drug design is currently a common practice in both drug industries and academic institutes. According to the characteristics of breast cancer, we selected multiple candidate compounds; based on the corresponding molecular descriptors, biological activities, and pharmacokinetic properties, a dataset of inhibition potency and pharmacokinetic properties paired with multiple features of compounds was constructed. On this basis, the random forest method was utilized to choose greater-influenced feature embeddings; thus, 224 main operating variables were selected for further analysis; we then employed the efficient MobileNetV3 deep neural network as the backbone to establish the prediction models for the inhibition potency and pharmacokinetic properties of the compounds. After data preprocessing, the weights are obtained by training on the refined dataset. Finally, we define an optimization problem to discover compounds with the best properties. The problem is solved using the genetic algorithm with the acquired prediction model, and the solution value for the corresponding operating variables with the best clinical properties in theory is then obtained. Analysis demonstrates that our approach could be used to aid the screening process of antibreast cancer drug candidates.

Development of triphala churna extract mediated iron oxide nanoparticles as novel treatment strategy for triple negative breast cancer

The present work demonstrates the eco-friendly green synthesis of Iron oxide nanoparticles from the aqueous extract of Triphala churna (TIONPs) using ferric chloride hexahydrate (FeCl3.6H2O) precursor in a single-step process. The formulated TIONPs were characterized by various instrumental techniques such as UV–Visible spectrophotometry (UV–Vis), Atomic absorption spectroscopy (AAS), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Scanning electron microscope (SEM), Dynamic light scattering- Zeta potential (DLS-Zeta sizer), and Superconducting quantum interference device (SQUID) to establish their physico-chemical characteristics. The average size range of obtained spherical TIONPs was found in between 29 and 74 nm. Further, the MTT assay and Nuclear staining assay were carried out on Triple negative breast cancer (TNBC) cell lines along with a breast cancer associated epidermoid skin carcinoma cell line. The MTT assay revealed prominent cytotoxic activity of TIONPs against the tested cancer cell lines. Additionally, the nuclear staining assay revealed that the cytotoxic activity of these nanoparticles occurred via apoptosis mode by exhibiting nuclear fragmentation, cytoplasmic shrinkage, and cell blebbing. These TIONPs were also found to possess superparamagnetic property which may be additionally beneficial for their rapid and organ targeted delivery. Hence, the green synthesized TIONPs can be explored in near future as a new promising option for TNBC management.

Modulating Microbiota as a New Strategy for Breast Cancer Prevention and Treatment.

Breast cancer (BC) is the most common cancer in women in the United States. There has been an increasing incidence and decreasing mortality rate of BC cases over the past several decades. Many risk factors are associated with BC, such as diet, aging, personal and family history, obesity, and some environmental factors. Recent studies have shown that healthy individuals and BC patients have different microbiota composition, indicating that microbiome is a new risk factor for BC. Gut and breast microbiota alterations are associated with BC prognosis. This review will evaluate altered microbiota populations in gut, breast tissue, and milk of BC patients, as well as mechanisms of interactions between microbiota modulation and BC. Probiotics and prebiotics are commercially available dietary supplements to alleviate side-effects of cancer therapies. They also shape the population of human gut microbiome. This review evaluates novel means of modulating microbiota by nutritional treatment with probiotics and prebiotics as emerging and promising strategies for prevention and treatment of BC. The mechanistic role of probiotic and prebiotics partially depend on alterations in estrogen metabolism, systematic immune regulation, and epigenetics regulation.

ERα-LBD, an isoform of estrogen receptor alpha, promotes breast cancer proliferation and endocrine resistance

Estrogen receptor alpha (ERα) drives mammary gland development and breast cancer (BC) growth through an evolutionarily conserved linkage of DNA binding and hormone activation functions. Therapeutic targeting of the hormone binding pocket is a widely utilized and successful strategy for breast cancer prevention and treatment. However, resistance to this endocrine therapy is frequently encountered and may occur through bypass or reactivation of ER-regulated transcriptional programs. We now identify the induction of an ERα isoform, ERα-LBD, that is encoded by an alternative ESR1 transcript and lacks the activation function and DNA binding domains. Despite lacking the transcriptional activity, ERα-LBD is found to promote breast cancer growth and resistance to the ERα antagonist fulvestrant. ERα-LBD is predominantly localized to the cytoplasm and mitochondria of BC cells and leads to enhanced glycolysis, respiration and stem-like features. Intriguingly, ERα-LBD expression and function does not appear to be restricted to cancers that express full length ERα but also promotes growth of triple-negative breast cancers and ERα-LBD transcript (ESR1-LBD) is also present in BC samples from both ERα(+) and ERα(−) human tumors. These findings point to ERα-LBD as a potential mediator of breast cancer progression and therapy resistance.

New advances in medical imaging technology for the evaluation of anthracycline-induced cardiotoxicity.

New advances in medical imaging technology for the evaluation of anthracycline-induced cardiotoxicity.

The cross-talk of autophagy and apoptosis in breast carcinoma: implications for novel therapies?

Breast cancer is still the most common cancer in women worldwide. Resistance to drugs and recurrence of the disease are two leading causes of failure in treatment. For a more efficient treatment of patients, the development of novel therapeutic regimes is needed. Recent studies indicate that modulation of autophagy in concert with apoptosis induction may provide a promising novel strategy in breast cancer treatment. Apoptosis and autophagy are two tightly regulated distinct cellular processes. To maintain tissue homeostasis abnormal cells are disposed largely by means of apoptosis. Autophagy, however, contributes to tissue homeostasis and cell fitness by scavenging of damaged organelles, lipids, proteins, and DNA. Defects in autophagy promote tumorigenesis, whereas upon tumor formation rapidly proliferating cancer cells may rely on autophagy to survive. Given that evasion of apoptosis is one of the characteristic hallmarks of cancer cells, inhibiting autophagy and promoting apoptosis can negatively influence cancer cell survival and increase cell death. Hence, combination of antiautophagic agents with the enhancement of apoptosis may restore apoptosis and provide a therapeutic advantage against breast cancer. In this review, we discuss the cross-talk of autophagy and apoptosis and the diverse facets of autophagy in breast cancer cells leading to novel models for more effective therapeutic strategies.

Identification of UCP1 and UCP2 as Potential Prognostic Markers in Breast Cancer: A Study Based on Immunohistochemical Analysis and Bioinformatics.

Background: Uncoupling protein 1 (UCP1) and UCP2 are associated with tumor metabolism and immunity. However, the prognostic value and molecular mechanisms underlying their action in breast cancer (BC) remain unclear. Materials and methods: In TCGA-BRCA cohort, we investigated the expression characteristics of UCP mRNAs, analyzed their prognostic value by Kaplan-Meier survival analysis, their potential molecular functions by gene set enrichment analysis, and their relationship with immune infiltrating cell types using TIMER and CIBERSORT, along with the assessment of their association with mutational profiles. Kaplan-Meier survival analysis was performed for UCPs in our cohort and their association with BC thermogenesis was assessed by thermal tomography. Results: High expression of UCP1 and UCP2 were positive prognostic markers for BC. UCP1 was associated with the impaired glucose metabolism, while UCP2 with enhanced anti-tumor immunity. High expressions of UCP1 and UCP2 were associated with CDH1 mutations. High UCP1 expression was associated with a high rate of thermogenesis in BC. Conclusions: These results implied a key role of UCP1 and UCP2 in prognosis, metabolism, and immune infiltration in BC. Further investigation of the relevant molecular mechanisms may provide new strategies for BC treatment.

Green Synthesis of a Novel Silver Nanoparticle Conjugated with Thelypteris glandulosolanosa (Raqui-Raqui): Preliminary Characterization and Anticancer Activity

In the last decade, the green synthesis of nanoparticles has had a prominent role in scientific research for industrial and biomedical applications. In this current study, silver nitrate (AgNO3) was reduced and stabilized with an aqueous extract of Thelypteris glandulosolanosa (Raqui-raqui), forming silver nanoparticles (AgNPs-RR). UV-vis spectrophotometry, dynamic light scattering (DLS), and scanning transmission electron microscopy (STEM) were utilized to analyze the structures of AgNPs-RR. The results from this analysis showed a characteristic peak at 420 nm and a mean hydrodynamic size equal to 39.16 nm, while the STEM revealed a size distribution of 6.64–51.00 nm with an average diameter of 31.45 nm. Cellular cytotoxicity assays using MCF-7 (ATCC® HTB-22™, mammary gland breast), A549 (ATCC® CCL-185, lung epithelial carcinoma), and L929 (ATCC® CCL-1, subcutaneous connective tissue of Mus musculus) demonstrated over 42.70% of MCF-7, 59.24% of A549, and 8.80% of L929 cells had cell death after 48 h showing that this nanoparticle is more selective to disrupt neoplastic than non-cancerous cells and may be further developed into an effective strategy for breast and lung cancer treatment. These results demonstrate that the nanoparticle surfaces developed are complex, have lower contact angles, and have excellent scratch and wear resistance.

An Innovative Arteriovenous (AV) Loop Breast Cancer Model Tailored for Cancer Research.

Animal models are important tools to investigate the pathogenesis and develop treatment strategies for breast cancer in humans. In this study, we developed a new three-dimensional in vivo arteriovenous loop model of human breast cancer with the aid of biodegradable materials, including fibrin, alginate, and polycaprolactone. We examined the in vivo effects of various matrices on the growth of breast cancer cells by imaging and immunohistochemistry evaluation. Our findings clearly demonstrate that vascularized breast cancer microtissues could be engineered and recapitulate the in vivo situation and tumor-stromal interaction within an isolated environment in an in vivo organism. Alginate–fibrin hybrid matrices were considered as a highly powerful material for breast tumor engineering based on its stability and biocompatibility. We propose that the novel tumor model may not only serve as an invaluable platform for analyzing and understanding the molecular mechanisms and pattern of oncologic diseases, but also be tailored for individual therapy via transplantation of breast cancer patient-derived tumors.

Post-Neoadjuvant Treatment in HER2-Positive Breast Cancer: Escalation and De-Escalation Strategies.

Simple SummaryThe response to neoadjuvant treatment is strongly associated with the clinical outcome of breast cancer patients, especially in the HER2-positive subtype of the disease. In HER2-positive patients with a residual tumor burden, an escalation of post-neoadjuvant therapy leads to the improvement of survival, while (post)-neoadjuvant treatment de-escalation is currently being discussed in low-risk settings in order to avoid unnecessary toxicities.Patients with high-risk non-metastatic breast cancer are recommended for chemotherapy, preferably in the neoadjuvant setting. Beyond advantages such as a better operability and an improved assessment of individual prognosis, the preoperative administration of systemic treatment offers the unique possibility of selecting postoperative therapies according to tumor response. In patients with HER2-positive disease, both the escalation of therapy in the case of high-risk features and the de-escalation in patients with a low tumor load are currently discussed. Patients with small node-negative tumors receive primary surgery and, upon confirmation of pathological T1 N0 status, de-escalated adjuvant therapy with paclitaxel and trastuzumab. For those with a large tumor and/or nodal involvement, neoadjuvant polychemotherapy with a dual antibody blockade is recommended. Patients with invasive residual disease benefit from switching postoperative therapy to the antibody-drug-conjugate trastuzumab emtansine (T-DM1). In this review, we discuss current evidence and controversies regarding post-neoadjuvant treatment strategies in HER2-positive breast cancer.

Abstract 3333: Pre-clinical investigation of neratinib plus dasatinib in breast cancer

Abstract Background: HER2-targeted therapies have revolutionized the prognosis of HER2-positive (HER2+) breast cancer (BC). However, the emergence of acquired resistance or de novo resistance are persistent clinical problems. The objective of this study was to examine neratinib (NER), an irreversible pan-HER inhibitor approved for early-stage and metastatic HER2+ BC, and dasatinib (DAS), a multi-kinase inhibitor used to treat certain leukemias, as a new treatment for HER2-targeted therapy resistant HER2+ BC and triple negative BC (TNBC). Methods: The anti-proliferative effect of NER plus DAS was screened in a panel of 20 breast cancer cell lines using a 5-day acid phosphatase assay. This panel included 12 HER2+ (3 trastuzumab (TRAS) sensitive (SKBR3, BT474, EFM192A), 2 acquired TRAS resistant (BT474-T, SKBR3-T), 3 innately TRAS resistant (HCC1954, HCC1569, JIMT1), and 4 acquired neratinib resistant cell lines (HCC1954-N, HCC1569-N, SKBR3-N, BT474-N), 6 triple negative (BT20, HCC1143, HCC1937, MDA-MB- 157/231/468), and 2 estrogen receptor positive (ER+) cell lines (MCF7, ZR-75-1). Drug synergy was examined using Combenefit and Calcusyn software. Combination Index (CI) values < 1 indicated synergy, > 1 antagonism. Neratinib IC50 values < 150nM were considered physiologically relevant. Prolonged exposure in vitro efficacy was tested in these cell lines by treating twice weekly with NER +/- DAS until resistance emerged. Cell confluence was then quantified using a crystal violet-based method. The safety and efficacy of NER (10 mg/kg) plus DAS (15 mg/kg) was investigated in vivo in HER2+ HCC1954 xenografts in BALB/c nude mice. Results: NER was highly effective against HER2+ BC cell lines regardless of TRAS sensitivity (IC50 values range 1-172 nM), showed moderate activity in TNBC (IC50 value range 31 nM - >1 μM), and did not achieve <1 μM activity in ER+ BC cell lines. NER resistant cell lines had IC50 values greater than 150 nM DAS alone displayed IC50 values from 8-135 nM in 4/6 TNBC cell lines, with all 6 TNBC cell lines sensitive to either the single agents or the combination at concentrations less than 100 nM. DAS enhanced the anti-proliferative activity of NER in the HCC1954, HCC1569, JIMT1 cell lines (CI values = 0.27-0.62). The NER/DAS combination overcame NER resistance in all acquired NER-resistant cell line models and no antagonism was observed in any cell line tested. Matrix assays confirmed synergy at low nanomolar concentrations of both drugs. NER plus DAS had a greater long term in vitro anti-proliferative effect over NER in HCC1954, HCC1569, and JIMT1 cells, preventing or delaying the development of NER resistance. NER plus DAS was well tolerated in mice for over 60 days. The combination was better than single agents and showed prolonged anti-tumor effect against HCC1954 xenografts in vivo (p=0.02). Conclusions: This study suggests that the addition of DAS to NER may have potential as a new treatment strategy for BC, particularly for HER2+ BC. Citation Format: Neil T. Conlon, Sandra Roche, Fiona O'Neill, Justine Meiller, John Crown, Denis M. Collins. Pre-clinical investigation of neratinib plus dasatinib in breast cancer [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 3333.

Abstract 6161: HER3 expression is associated with cold tumor immune microenvironment and the regulation of its signal in humanized breast cancer patient derived xenograft models converts to hot tumor

Abstract Background: HER3 signal pathways in cancer cells are thought to be involved in up-regulation of PD-L1 expression, resulting in “cold” tumor immune microenvironment (TIME). However, little is known on the association of HER3 expression and immune related molecular network in breast cancer and the functional role of HER3 signals in antitumor immune responses. Methods: The dataset of the TCGA study was analyzed to determine the correlation of HER3 expression and antitumor immune molecules. Two breast cancer patient-derived xenograft (PDX) models were treated with patritumab (anti-HER3 antibody), polyclonal activated autologous T cells (PATCs) or a combination of patritumab and PATCs (P-PATCs) in order to test immunological modulation by the regulation of HER3 signals. RT-PCR, immunohistochemical staining and CyTOF were performed in tumors or liver tissue for CD3, CD4, CD8a, CD137, CD134/OX40, CD80, IFN-γ and PD-L1, LAG3, TIM3, FOXP3. In addition, HER3-knockdown human breast cancer cell lines and PBMC were co-cultured and comprehensive cytokine expression in supernatant was analyzed by bioplex. Results: In TCGA dataset analysis, HER3 expression was inversely corelated with expression of CD4, CD8A, IFN-γ, granzyme A/B. In humanized PDX models, although treatment of PATCs or patritumab alone showed limited anti-tumor effects, P-PATCs treatment showed a significantly greater anti-tumor response. Interestingly, the proportion of CD137 expressing T cell infiltration and mRNA expression of CD137 was significantly higher in P-PATCs group compared to patritumab or the PATCs group, while the proportion of CD4/8 T cell infiltration was also higher in the P-PATCs group. CyTOF revealed that the proportion of CD137 and CD134/OX40 expressing cells was higher in P-PATCs group compared to the PATCs group. In co-culture of PBMC with HER3 knockdown cancer cells, the secretion level of immune stimulatory factors (IL2, IFN-g, TNF-a) increased and immune inhibitors (IL6, IL10) decreases. Conclusions: These data suggest that HER3 expression in breast cancer associated with “cold” TIME and the regulation of its signal converts “cold” TIME to “hot”. Thus, inhibition of HER3 signal might be of interesting concept for both regulation of oncologic signal and immunological modulation in HER3-expressing breast cancer. Further HER3 related immune modulation exploration in breast cancer treatment strategy needs to be clarified in the future. Citation Format: Sunao Tanaka, Eiji Suzuki, Takeshi Kotake, Shinpei Kawaoka, Kosuke Kawaguchi, Tomomi Nishimura, Fengling Pu, Masakazu Toi. HER3 expression is associated with cold tumor immune microenvironment and the regulation of its signal in humanized breast cancer patient derived xenograft models converts to hot tumor [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 6161.

Abstract 5084: KMT2D and PIK3CA mutation as potential factors to predict adjuvant chemotherapy efficacy in surgical triple negative breast cancer

Abstract Background: Chemotherapy is the most common treatment strategy for triple negative breast cancer (TNBC) patients. Nevertheless, due to adverse drug reactionsthe molecular high heterogeneity of TNBC and no appropriate meaningful efficacy markers, it is still difficult to establish preferred therapeutic strategies and predict the outcomes for TNBC. This study was to investigate the potential predictors and therapeutic targets based on genetic features. Methods: A total of 386 TNBC patients were randomized 1:1 to receive either six cycles of paclitaxel + cisplatin (TP) or four cycles of epirubicin + cyclophosphamide followed by four cycles of docetaxel (EC-T) adjuvant chemotherapy after surgery (NCT01150513), which were described previously. Finally, 149 TNBC patients with clinical and tumor sequencing data availability were retrospectively analysed by NGS for 733 cancer-related genes. All tumor samples were collected during the surgical operation and subjected to NGS for evaluating genomic mutations and the potential predictors. Cox regression model and Kaplan-Meier method were applied to evaluate disease-free survival (DFS). Results: In the surgical cohort receiving adjuvant chemotherapy, 74 patients received platinum and 75 received platinum-free chemotherapy as adjuvant chemotherapy. The most frequently mutated genes in this surgical TNBC cohort were TP53 (84%), BRCA1 (18%), BRCA2 (15%), POL1 (13%), PTEN (12%), REV3L (11%), FANCC (10%), and PARP4 (10%). We analyzed the associations between 733 cancer-related gene mutations and DFS after adjuvant chemotherapy. For the TP group, PIK3CA mutation (19%, 14/74) was discovered to correlate with poor DFS for patients treated with platinum-containing adjuvant therapy (HR=3.2, P=0.037), and KMT2D mutation (15%, 11/75) display worse DFS for patients treated with EC-T platinum-free group (HR=3.0, p=0.039). However, BRCA1/2 mutation (24%, 35/149) was found to be associated with poor prognosis (HR=2.1 (95% CI: 1-4.6), p=0.047), irrespective of therapeutic regimen. Conclusions: In this population of surgical TNBC patients, NGS analysis identified potential predictive markers. PIK3CA mutation in TP platinum-containing group and KMT2D mutation in EC-T platinum-free group were significantly associated to poor prognosis for adjuvant chemotherapy in triple negative breast cancer. Citation Format: Xue Wang, Feng Du, Jian Yue, Yiran Si, Lina Cui, Bei Zhang, Xiaochen Zhao, Binghe Xu, Peng Yuan. KMT2D and PIK3CA mutation as potential factors to predict adjuvant chemotherapy efficacy in surgical triple negative breast cancer [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 5084.

Abstract 264: Neutrophil elastase (NE) inhibition enhances metastasis free survival by altering regulation of tumor intrinsic cytoskeletal and cellular adhesion pathways in murine breast cancer models

Abstract Background: Neutrophil elastase (NE), a serine protease exclusively secreted in neutrophils, is a crucial mediator of chronic inflammation and tumor progression. Studies from our group reveal that NE may be a prognostic marker of metastasis. In a cohort of 192 breast cancer patients (58% ER/PR+ve, 20%-HER-2 +ve and 22% TNBC), our results show that higher infiltration of NE-positive Tumor Associated Neutrophils (TANs), is associated with a decrease in recurrence free survival (hazard ratio=3.4, 95% CI, 1.1-5.5), regardless of breast cancer subtype Further, we observe that the genetic deletion of Elane (encoding NE) inhibits lung metastasis in in vivo models of breast cancer. Yet the precise mechanism(s) by which NE promotes tumorigenesis and metastasis of breast cancer remains to be elucidated. To address this gap in knowledge, we have identified the tumor-intrinsic and -extrinsic mechanisms by which NE promotes metastasis. Methods: The role of NE in breast cancer metastasis was assessed using Elane+/+ and Elane-/- mice in FVB/NJ genetic background, bearing PyMT tumors (orthotopic and spontaneous) respectively. These mice develop lung metastasis in 80-90% of the tumor-bearing mice within 1-3 months of primary tumor initiation. To assess metastasis-free survival (MFS), mice received orthotopic engraftment of PyMT tumors, followed by resection and subsequent monitoring for metastasis. The efficacy of the NE inhibitor AZD9668 was assessed in Elane+/+ mouse models by treating the mice with 100mg/kg B.I.D treatments. Preliminary results: Genetic ablation of NE (Elane-/-) in the PyMT models, reduced lung metastasis by ~90% (Lung metastatic index =21.8 vs. 2.7, respectively; p=0.0044). Survival studies in FVB Elane-/- showed a MFS benefit of 345 days compared to controls, which succumbed to metastasis-related death in 46 days post primary tumor resection. RNA-sequencing analysis of PyMT- Elane+/+ and Elane-/- tumors showed differential regulation of tumor intrinsic actin cytoskeleton and integrin signaling pathways between the two genetic backgrounds. These NE-regulated pathways are critical for cell-to-cell contact and tissue integrity, explaining the delay in metastasis in the Elane-/- mice. 100mg/kg daily treatment of AZD9668 reduced lung metastasis in PyMT mice by 94% compared to vehicle-treated mice (0.49+/- 0.21% vs. 0.03+/-0.01%; p=0.05) and significantly reduced instances of primary tumor recurrence. Conclusions: Collectively, our studies suggest that genetic and pharmacological ablation of NE reduces metastasis and extends MFS in in vivo models of breast cancer. Our preclinical studies presented here are likely to provide the much-needed rationale for the use of this class of NE inhibitors as a viable treatment strategy for the metastatic breast cancer. Citation Format: Amriti R. Lulla, Said Akli, Lucas D. Warma, Natalie W. Fowlkes, Kelly K. Hunt, Xiayu Rao, Jing Wang, Stephanie S. Watowich, Khandan Keyomarsi. Neutrophil elastase (NE) inhibition enhances metastasis free survival by altering regulation of tumor intrinsic cytoskeletal and cellular adhesion pathways in murine breast cancer models [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 264.

A PDE Model of Breast Tumor Progression in MMTV-PyMT Mice.

The evolution of breast tumors greatly depends on the interaction network among different cell types, including immune cells and cancer cells in the tumor. This study takes advantage of newly collected rich spatio-temporal mouse data to develop a data-driven mathematical model of breast tumors that considers cells’ location and key interactions in the tumor. The results show that cancer cells have a minor presence in the area with the most overall immune cells, and the number of activated immune cells in the tumor is depleted over time when there is no influx of immune cells. Interestingly, in the case of the influx of immune cells, the highest concentrations of both T cells and cancer cells are in the boundary of the tumor, as we use the Robin boundary condition to model the influx of immune cells. In other words, the influx of immune cells causes a dominant outward advection for cancer cells. We also investigate the effect of cells’ diffusion and immune cells’ influx rates in the dynamics of cells in the tumor micro-environment. Sensitivity analyses indicate that cancer cells and adipocytes’ diffusion rates are the most sensitive parameters, followed by influx and diffusion rates of cytotoxic T cells, implying that targeting them is a possible treatment strategy for breast cancer.

RUNX2 recruits the NuRD(MTA1)/CRL4B complex to promote breast cancer progression and bone metastasis

Runt-related transcription factor 2 (RUNX2) is an osteogenesis-related transcription factor that has emerged as a prominent transcription repressing factor in carcinogenesis. However, the role of RUNX2 in breast cancer metastasis remains poorly understood. Here, we show that RUNX2 recruits the metastasis-associated 1 (MTA1)/NuRD and the Cullin 4B (CUL4B)-Ring E3 ligase (CRL4B) complex to form a transcriptional-repressive complex, which catalyzes the histone deacetylation and ubiquitylation. Genome-wide analysis of the RUNX2/NuRD(MTA1)/CRL4B complex targets identified a cohort of genes including peroxisome proliferator-activated receptor alpha (PPARα) and superoxide dismutase 2 (SOD2), which are critically involved in cell growth, epithelial-to-mesenchymal transition (EMT) and invasion. We demonstrate that the RUNX2/NuRD(MTA1)/CRL4B complex promotes the proliferation, invasion, tumorigenesis, bone metastasis, cancer stemness of breast cancer in vitro and in vivo. Strikingly, RUNX2 expression is upregulated in multiple human carcinomas, including breast cancer. Our study suggests that RUNX2 is a promising potential target for the future treatment strategies of breast cancer.

Characterization of Weakly Hormone Receptor (HR)-Positive, HER2-Negative Breast Cancer and Current Treatment Strategies

BackgroundHormone receptor (HR) and human epidermal growth factor receptor-2 (HER2) status is critical for determining management of breast cancer. Previous reports of small cohorts with weak HR-positive (HR+)/HER2-negative (HER2-) disease showed similar rates of pathologic complete response (pCR) following neoadjuvant chemotherapy (NAC) as triple negative breast cancer (TNBC). This study aims to further characterize this group, focusing on pCR rates following NAC. Patients and MethodsPatients with stage I-III, HR+/HER2- breast cancer were identified using the University of Wisconsin Hospital Cancer Registry. Medical records were reviewed for demographics, tumor characteristics with quantification level of estrogen and progesterone receptor (≤33%), treatment, and follow-up data. ResultsData was reviewed from 2,900 patients and a total of 64 patients met inclusion criteria. Eighty percent received chemotherapy, about half with NAC (n = 30, 48%). Of 28 patients who received NAC followed by breast and axillary surgery, 12 (43%; 95% CI 25%-63%) had pCR (ypT0/Tis/ypN0). Of the 11 patients who had biopsyproven nodal disease at diagnosis and NAC followed by axillary surgery, 7 (64%, 95% CI 31%-89%) patients had pCR at the axilla. Only one patient with pCR developed recurrent disease. For those that recurred, median time to recurrence was 13.6 (5.6-48.7) months. ConclusionsBreast cancers that are HER2- and weakly HR+ treated with NAC demonstrated pCR rate more similar to TNBC than breast cancers that are strong HR+. Neoadjuvant approaches may improve pCR rates, which provides important prognostic information. Clinical trials should be developed to focus on this unique patient cohort.

Differential Response of MED12 Downregulated Breast Cancer to Targeted Therapy

MED12 is a subunit of a large multi‐subunit protein complex called Mediator. Mediator plays critical roles in gene regulation by repressing or activating transcription through modulation of RNA polymerase II. The specific role of MED12 within Mediator is to regulate the activity of CDK8 kinase. Many studies in the last several years have uncovered that mutations within MED12 or downregulation of MED12 leads to dysregulation of CDK8 kinase activity which has many physiological implications, including promotion of tumorigenesis in a variety of different cancers. Specifically, MED12 mutations have been found in up to 67% of breast cancer patients. Although many strides have been made towards finding superior treatment strategies for breast cancer, there is still a critical need for uncovering targeted therapies for specific genetic subsets of breast cancer. Therefore, we are aiming to find a superior treatment strategy for breast cancer patients who carry MED12 mutations. Natural compounds are a promising treatment option since more than 50% of drugs currently available in the pharmaceutical industry are derived from natural sources. Consequently, we have employed a screen of a natural compound library to discover novel therapeutics for MED12 mutant breast cancer. Specifically, we generated a stable MED12 knockdown MCF‐7 cell line through the use lentiviral‐mediated shRNA. Since MED12 mutations abolish MED12 functions, the MED12 knockdown cell line should mimic a MED12 mutant setting. We first confirmed that the MED12 knockdown cell line exhibits enhanced proliferation through the employment of proliferation assays. Next, we performed a natural compound screen as assayed by MTT cell viability assays and found that MED12 knockdown cells are differentially affected by the compounds. Our results indicated that MED12 knockdown cells appear to be more resistant to treatment when compared to MED12 wildtype cells, although we did also uncover compounds that differentially targeted MED12 knockdown cells. We selected out the compounds that differentially targeted MED12 knockdown cells and subjected them to quantitative PCR analysis. MED12 has previously been shown to place a constraint on GLI3‐mediated SHH signaling, a finding that is of interest since SHH signaling is often hyperactivated in breast cancer. We therefore examined the expression of GLI3 target genes in our MED12 knockdown cell line that were either treated with control vehicle or selected natural compounds. Interestingly, we found that GLI3 signaling is upregulated in MED12 knockdown cells, and more importantly, the upregulation is drastically reversed in the compound‐treated cells. Overall, our results demonstrate that natural compounds could prove to be an effective targeted therapy for MED12 mutant breast cancer by targeting the GLI3‐mediated SHH signaling pathway.