Breast Cancer Research最新文献

Background: Breast cancer is the leading cause of female mortality worldwide. (SET And MYND Domain Containing 4) SMYD4 has been reported to be a tumour suppressor. However, the molecular mechanism of SMYD4 remains unclear.

Methods: The expression level of SMYD4 in breast cancer cells was detected by qRT-PCR and western blot. The effect of SMYD4 was verified in vitro and in vivo. The interaction between SMYD4 and MYH9 was investigated by co‑IP assay. The regulation of SMYD4 on WNT signaling pathway was detected by luciferase reporter assay and ChIP analysis.

Results: This study found that SMYD4 downregulation was associated with poor prognosis. SMYD4 was performed as a tumor suppressor both in vitro and in vivo. SMYD4 was found to interact with the downstream protein MYH9 and impede WNT signaling pathway. Further studies revealed that SMYD4 impeded the binding of MYH9 to the CTNNB1 promoter region by promoting lysine monomethylation and ubiquitination degradation of MYH9.

Conclusions: These findings reveal the emerging character of SMYD4 in Wnt/β‑catenin signaling and bring new sights of gene interaction. The discovery of this SMYD4/MYH9/CTNNB1/WNT/β-Catenin signalling pathway axis suggests that SMYD4 is a potential therapeutic target for breast cancer.

Background: Breast Cancer (BC) is the most common type of cancer in women around the world and 70% of cases are hormone-receptor positive (HR+). In 40% of cases, a key mechanism of endocrine resistance to the standard first line is a mutation of the ligand-binding domain (LBD) of Estrogen Receptor 1 (ESR1) encoding estrogen receptor α (ER). Most common ESR1 mutations that occur at positions 537 and 538 have been associated with poor clinical outcomes. ESR1 mutations have the potential to provide neoantigens. This study aims to identify if ESR1 mutations generate specific T cell responses against ESR1 neoantigens in patients with HR⁺ HER2^- BC, and to investigate if ESR1 mutations might correlate with a gene expression profile related to immune surveillance disruption.

Methods: We identified candidate ESR1-derived peptides by predictive software (SYFPEITHI and NetMHCpan 3.0). Then the immunogenicity of ESR1-derived peptides was assessed in Peripheral-Blood-Mononuclear-Cells from 31 healthy donors (HD) and 25 patients with metastatic HR-positive BC by IFN-γ ELISpot assay. A vaccination assay on a humanized mouse model (HLA-A2/DR1) was used to validate the immunogenicity and the presentation of these peptides. Finally, we used Bulk RNA-Seq sequencing along with MCPcounter, a cellular deconvolution method, to investigate the immune contexture of ESR1-mutated BC.

Results: Preliminary results showed recognition of ESR1-derived peptides by women HD lymphocytes but not in men. Frequencies and intensities of such immune responses were increased in patients with BC. Our results showed that 40% of patients had specific immune responses. In addition, we demonstrated the HLA-A2 ESR1 peptide immunogenicity in humanized HLA-A2/DR1 mice. In a data set generated from BC patients refractory to conventional therapy we showed that ESR1 mutations are correlated in advanced diseases with downregulation of molecules involved in antigen presentation and with loss HLA Class I gene expression. ESR1-mutated BC had a decrease in immune cell infiltration.

Conclusion: These results support that common ESR1 mutations generate neoantigens in hormone-receptor positive metastatic breast cancers. If ESR1 peptides-restricted lymphocytes were detectable in BC patients, ESR1 mutations promote immune escape at advanced stages.

Trial registration: ClinicalTrials.gov, NCT02838381. Registered on June 2012.

Background: Tumour vascular density assessed from CD-31 immunohistochemistry (IHC) images has previously been shown to have prognostic value in breast cancer. Current methods to measure vascular density, however, are time-consuming, suffer from high inter-observer variability and are limited in describing the complex tumour vasculature morphometry.

Methods: We propose a method for automatically measuring a range of vascular parameters from CD-31 IHC images, which together provide a detailed description of the vasculature morphology. We first used a U-Net based convolutional neural network, trained and validated using 36 partially annotated whole slide images from 27 patients, to segment vessel structures and tumour regions from which the measurements are taken. The model also segments the vascular smooth muscle, benign epithelium, adipose tissue, stroma, lymphocyte clusters, nerves and CD-31 positive leukocytes, and we applied it to an additional 21 images from 15 patients. Using these segmentations, we investigated the relationship between the various tissue types and the vasculature and studied the relationship of various vascular parameters with clinical parameters. We also performed a 3D histology analysis on a separate tumour sample as a proof of principle, providing a more comprehensive visualization of vasculature morphology compared to the standard 2D cross-section of a tissue sample.

Results: Using two-way cross-validation, we show that vessels were accurately segmented, with Dice scores of 0.875 and 0.856, and were accurately identified, with F1 scores of 0.777 and 0.748. All vascular parameters exhibit strong ( $r>0.7$ ) and significant (p<0.001) correlations with measurements taken from the manual ground truth vessel segmentations. A significant relationship between the major/minor axis ratio, a measure of elongation, and the tumour grade was found.

Conclusion: Our proposed method shows promise as a tool for studying the tumour vasculature and its relationship with surrounding cells and tissue types. Furthermore, the correlation with tumour grade highlights the clinical relevance of our approach. These findings suggest that our method could have substantial implications for improving prognostic assessments and personalizing therapeutic strategies in breast cancer treatment.

Background: Mammographic breast density (MBD), a strong predictor of breast cancer, is highly influenced by body mass index (BMI) in childhood and early adulthood, but the mechanisms underlying these associations are not fully understood. Our goal is to identify biomarkers that mediate the associations of BMI at ages 10 and 18 with MBD in premenopausal women.

Methods: This study consists of 705 premenopausal women who had their screening mammogram at Washington University in St. Louis, MO, and provided a fasting blood sample. Our comprehensive metabolomic and lipidomic profiling yielded complete data for 828 metabolites and 857 lipid species after imputation. We used Volpara to determine volumetric measures of MBD. We performed high dimensional mediation analysis using the HIMA R package, adjusted for confounders, to determine whether lipid species and metabolites mediate the associations of BMI at 10 and 18 with MBD. We applied a false discovery rate (FDR) p-value < 0.1.

Results: Four metabolites (glutamate, β-cryptoxanthin, cortolone glucuronide (1), phytanate) significantly mediated the association of BMI at 10 with volumetric percent density (VPD), and two (glutamate, β-cryptoxanthin) mediated the association of BMI at 18 with VPD. Glutamate was the strongest mediator across time points. Glutamate mediated 6.7% (FDR p-value = 0.06) and 9.3% (FDR p-value = 0.008) of the association between BMI at age 10 and 18, respectively. Four lipid species (CER(18:0), LCER(14:0), LPC(18:1), PC(18:1/18:1)), mediated the association of BMI at 10 with VPD, while five lipid species (CER(18:0), LCER(14:0), PC(18:1/18:1), TAG56:5-FA22:5, TAG52:2-FA16:0) mediated the association of BMI at 18 with VPD. The strongest mediator was PC(18:1/18:1), which mediated 9.7%, (FDR-p = 0.009) and 7.7%, (FDR-p = 0.04) of the association of BMI at age 10 and 18 with VPD, respectively.

Conclusions: Metabolites in amino acid, lipid, cofactor/vitamin, and xenobiotic super-pathways as well as lipid species across the phospholipid, neutral complex lipid and sphingolipid super-pathways mediated the associations of BMI in early-life and MBD in premenopausal women. This study offers insight into the biological mechanisms underlying the link between early-life adiposity and MBD, which can support future research into breast cancer prevention.

Background: Trastuzumab deruxtecan (T-DXd) is FDA-approved for treatment of patients with HER2 positive and HER2-low metastatic breast cancer. Currently, there is limited understanding of pre-treatment risk factors for pneumonitis associated with T-DXd.

Methods: Consecutive breast cancer patients who received at least one dose of T-DXd at a single academic cancer study between January 1, 2019, and February 20, 2024, were identified for analysis. Pneumonitis was documented by the treating oncologist at the time of toxicity and retrospectively independently confirmed by a member of the study team through chart and radiologic review. Pre-treatment variables of interest were collected, including patient demographics, radiation dosimetry variables, and chest imaging abnormalities.

Results: Of 179 total patients, 23 (12.8%) had pneumonitis after T-DXd exposure. Patients with pneumonitis had lower baseline oxygen saturation (98% vs. 97%, p = 0.02) and were more likely to have received abemaciclib (26.1% vs. 9.6%, p = 0.03) before T-DXd. Multiple pre-treatment variables were not found to be associated with T-DXd pneumonitis, including chest imaging abnormalities (41.9% vs. 47.8%, p = 0.59), prior immune checkpoint inhibitor treatment (16.0% vs. 8.7%, p = 0.50) and prior chest or breast radiation (61.5% vs. 47.8%, p = 0.20). On multivariate analysis, prior treatment with abemaciclib remained significantly associated with T-DXd pneumonitis (OR 3.25 [1.07-9.11], p = 0.04), while neither pre-treatment chest imaging abnormalities nor prior chest or breast radiation were associated (OR 1.60 [0.62-4.20], p = 0.33); OR 0.51 [0.20-1.33], p = 0.17).

Conclusions: In this cohort, prior treatment with abemaciclib may be a risk factor for T-DXd pneumonitis. Conversely, pre-treatment chest imaging abnormalities, prior immune checkpoint inhibitor treatment, and prior chest or breast radiation did not increase the risk of T-DXd pneumonitis. Larger studies are warranted to validate these findings toward an improved understanding of risk factors for pneumonitis after T-DXd exposure.

Background: CDK4/6 inhibitors have significantly improved the survival of patients with HR-positive/HER2-negative breast cancer, becoming a first-line treatment option. However, the development of resistance to these inhibitors is inevitable. To address this challenge, novel strategies are required to overcome resistance, necessitating a deeper understanding of its mechanisms. Recent research has identified several dysregulated genes in CDK4/6 inhibitors-resistant breast cancer, but the underlying mechanism is complex due to tumor heterogeneity and warrants further investigation.

Methods: RNA sequencing and KEGG pathway analysis was carried out to identify the mainly dysregulated genes in CDK4/6 inhibitors-resistant breast cancer cells. The effects of CXCR4 knockdown and overexpression via siRNAs and plasmids transfection were examined by mammosphere formation, RT-qPCR, flow cytometry, MTT and colony formation assays. The regulation mechanisms were analyzed by RT-qPCR, western blotting and immunofluorescence experiments. Mouse xenografts were used to analyze the role of CXCR4 in regulation palbociclib sensitivity in vivo. Additionally, we collected the clinical samples and performed immunohistochemistry to analyze the clinical significance of CXCR4.

Results: In our study, we focused on cancer stem cells, a critical contributor to cancer metastasis and therapy resistance, and detected an upregulation of stemness in our established palbociclib-resistant ER-positive breast cancer cells. Additionally, our research pinpointed CXCR4 as a pivotal gene responsible for maintaining cancer stemness and promoting palbociclib resistance. Mechanistically, CXCR4 activates the WNT5A/β-catenin signaling pathway by enhancing the expression of WNT5A and β-catenin, facilitating the nuclear translocation of β-catenin protein. Targeting CXCR4 using siRNAs or small molecular inhibitors effectively reduces cancer stemness and reverses palbociclib resistance both in vitro and in vivo. Clinical sample analysis further underscores the overactivation of the CXCR4/WNT5A/β-catenin axis in palbociclib-resistant breast cancer, suggesting CXCR4 as a potential biomarker for predicting resistance to CDK4/6 inhibitors.

Conclusions: Collectively, our study demonstrates that CXCR4 overexpression plays a vital role in maintaining breast cancer stemness and promoting resistance to CDK4/6 inhibitors through the activation of the WNT5A/β-catenin pathway. Targeting CXCR4 may offer a promising therapeutic approach for advanced CDK4/6 inhibitor-resistant ER-positive breast cancer.

Background: Pathological complete response (pCR) is an established surrogate marker for prognosis in patients with breast cancer (BC) after neoadjuvant chemotherapy. Individualized pCR prediction based on clinical information available at biopsy, particularly immunohistochemical (IHC) markers, may help identify patients who could benefit from preoperative chemotherapy.

Methods: Data from patients with HER2-negative BC who underwent neoadjuvant chemotherapy from 2002 to 2020 (n = 1166) were used to develop multivariable prediction models to estimate the probability of pCR (pCR-prob). The most precise model identified using cross-validation was implemented in an online calculator and a nomogram. Associations among pCR-prob, prognostic IHC3 distant recurrence and disease-free survival were studied using Cox regression and Kaplan-Meier analyses. The model's utility was further evaluated in independent external validation cohorts.

Results: 273 patients (23.4%) achieved a pCR. The most precise model had across-validated area under the curve (AUC) of 0.84, sensitivity of 0.82, and specificity of 0.71. External validation yielded AUCs between 0.75 (95% CI, 0.70-0.81) and 0.83 (95% CI, 0.78-0.87). The higher the pCR-prob, the greater the prognostic impact of pCR status (presence/absence): hazard ratios decreased from 0.55 (95% central range, 0.07-1.77) at 0% to 0.20 (0.11-0.31) at 50% pCR-prob. Combining pCR-prob and IHC3 score further improved the precision of disease-free survival prognosis.

Conclusions: A pCR prediction model for neoadjuvant therapy decision-making was established. Combining pCR and recurrence prediction allows identification of not only patients who benefit most from neoadjuvant chemotherapy, but also patients with a very unfavorable prognosis for whom alternative treatment strategies should be considered.

Tumor-infiltrating lymphocytes are considered clinically beneficial in breast cancer, but the significance of natural killer (NK) cells is less well characterized. As increasing evidence has demonstrated that the spatial organization of immune cells in tumor microenvironments is a significant parameter for impacting disease progression as well as therapeutic responses, an improved understanding of tumor-infiltrating NK cells and their location within tumor contextures is needed to improve the design of effective NK cell-based therapies. In this study, we developed a multiplex immunohistochemistry (mIHC) antibody panel designed to quantitatively interrogate leukocyte lineages, focusing on NK cells and their phenotypes, in two independent breast cancer patient cohorts (n = 26 and n = 30). Owing to the clinical evidence supporting a significant role for NK cells in HER2⁺ breast cancer in mediating responses to Trastuzumab, we further evaluated HER2^- and HER2⁺ specimens separately. Consistent with literature, we found that CD3⁺ T cells were the dominant leukocyte subset across breast cancer specimens. In comparison, NK cells, identified by CD56 or NKp46 expression, were scarce in all specimens with low granzyme B expression indicating reduced cytotoxic functionality. Whereas NK cell density and phenotype did not appear to be influenced by HER2 status, spatial analysis revealed distinct NK cells phenotypes regarding their proximity to neoplastic tumor cells that associated with HER2 status. Spatial cellular neighborhood analysis revealed multiple unique neighborhood compositions surrounding NK cells, where NK cells from HER2^- tumors were more frequently found proximal to neoplastic tumor cells, whereas NK cells from HER2⁺ tumors were instead more frequently found proximal to CD3⁺ T cells. This study establishes the utility of quantitative mIHC to evaluate NK cells at the single-cell spatial proteomics level and illustrates how spatial characteristics of NK cell neighborhoods vary within the context of HER2^- and HER2⁺ breast cancers.

Background: The PALLAS trial investigated the addition of palbociclib to standard adjuvant endocrine therapy to reduce breast cancer recurrence. This pre-specified analysis was conducted to determine whether adjuvant palbociclib benefited patients diagnosed with lower risk stage IIA disease compared to those with higher stage disease.

Methods: PALLAS was an international, multicenter, randomized, open-label, phase III trial, representing a public-private partnership between Pfizer, the Austrian Breast Cancer Study Group, and the U.S. ALLIANCE Foundation. Patients diagnosed with stage II-III, hormone-receptor-positive, HER2/neu negative breast cancer within 12 months of diagnosis had completed all definitive therapy aside from endocrine therapy (started within 6 months prior to study entry) were eligible. All patients were required to submit a formalin-fixed paraffin-embedded (FFPE) tumor block. Patients were randomly assigned 1:1 to receive standard adjuvant endocrine therapy (of physicians' choice) for at least 5 years with or without 2 years of palbociclib, administered orally at a starting dose of 125 mg daily, given for 21 days followed by a 7-day break.

Results: A total of 5,796 patients with HR + /HER2- early breast cancer (including 1,010 with stage IIA) were enrolled. Median follow-up was 50 months for stage IIA patients and 43.1 months overall. In the stage IIA cohort, 4-year iDFS in the palbociclib arm was 92.9% versus 92.1% for ET alone (HR 0.75, 95%CI 0.48-1.19, p = 0.23). There was no differential benefit by histologic grade, chemotherapy receipt, age, or anatomic/clinical risk. Additionally, no benefit to palbociclib was seen in this cohort in invasive breast cancer-free survival (iBCFS), locoregional relapse-free survival (LRFS), distant relapse-free survival (DRFS), or overall survival (OS). For the stage IIB/III patients, 4-year iDFS was 85.3% for palbociclib + ET versus 83.6% for ET alone (HR 0.91, 95% CI 0.77-1.07, p = 0.24).

Conclusions and relevance: While there were substantial differences in outcome for stage IIA versus IIB/III patients at 4 years of follow-up, the addition of 2 years of palbociclib did not improve outcomes for patients, regardless of stage.

Trial registration: ClinicalTrials.gov number NCT02513394 Registered 30 Jul 2015.

Obesity is a modifiable risk factor for breast cancer. Yet, how obesity contributes to cancer initiation is not fully understood. The goal of this study was to determine if the body mass index (BMI) and metabolic hallmarks of obesity are related to DNA damage in normal breast tissue. In a mouse model of diet-induced obesity, weight gain was associated with elevated levels of DNA double-strand breaks in the mammary gland. We also found a positive correlation between BMI and DNA breaks in the breast epithelium of premenopausal women (but not postmenopausal women). High BMI was associated with elevated systemic and tissue-level oxidative DNA damage across the lifespan, and we propose that the breast epithelium undergoing menstruous proliferation waves is particularly prone to the generation of DNA breaks from oxidative lesions. Ancestry was an important modulator of the obesity-DNA break connection. Compared to non-Hispanic Whites, women identifying as African Americans had higher levels of DNA breaks, as well as elevated leptin and IGF-1. In 3D cultures of breast acini, both leptin and IGF-1 caused an accumulation of DNA damage. The results highlight a connection between premalignant genomic alterations in the breast epithelium and metabolic health modulated by obesity and ancestry. They call for attention on biological determinants of breast cancer risk disparities.