Modelling the role of dual specificity phosphatases in herceptin resistant breast cancer cell lines

Effectiveness and Safety of Zercepac and Reference Trastuzumab in the Neoadjuvant Setting for Early-Stage Breast Cancer: A Retrospective Cohort Study

Aim

Since the high cost of reference trastuzumab limits its clinical application, this study aimed to compare the effectiveness and safety of the Zercepac and reference product trastuzumab in neoadjuvant therapy for HER2-positive breast cancer.

Methods

This study retrospectively collected clinical data of patients with early-stageHER2-positive breast cancer, who received trastuzumab, pertuzumab, docetaxel, and platinum as neoadjuvant therapy from November 2020 to July 2021. Patients were divided into the Zercepac and reference trastuzumab groups. Reduction in tumor size, clinical response based on RECIST1.1 criteria, pathological complete response (pCR), and adverse events (AEs) were evaluated. Multivariate logistic regression analyses were used to adjust confounders.

Results

A total of 105 patients were included in the study, among them, 65 were in the Zercepac group and 40 were in the reference trastuzumab group. The percentage of tumor shrinkage from baseline was comparable between the Zercepac and reference trastuzumab group (47.6 ± 18.6% vs. 43.0 ± 19.9%, p = 0.235). Clinical partial response rate was similar between the two groups (81.5% vs. 70.0%, p = 0.172). There were 28 cases of pCR (70.0%) in the reference trastuzumab group and 46 cases of pCR (70.8%) in the Zercepac group (p = 0.933). The choice of Zercepac or reference trastuzumab was not significantly associated with pCR (OR = 0.96, 95%CI: 0.41-2.28, p = 0.933). Adverse events (AEs) were observed in all patients, and the incidence of ≥3 grade AEs was comparable between the two groups (81.5% vs. 70.0%, p = 0.172).

Conclusion

Zercepac has similar effectiveness and safety profile compared with reference trastuzumab in neoadjuvant therapy, which provides treatment options for patients with HER2-positive breast cancer.

Immune Cell Infiltration-Based Characterization of Triple-Negative Breast Cancer Predicts Prognosis and Chemotherapy Response Markers

Breast cancer represents the number one cause of cancer-associated mortality globally. The most aggressive molecular subtype is triple negative breast cancer (TNBC), of which limited therapeutic options are available. It is well known that breast cancer prognosis and tumor sensitivity toward immunotherapy are dictated by the tumor microenvironment. Breast cancer gene expression profiles were extracted from the METABRIC dataset and two TNBC clusters displaying unique immune features were identified. Activated immune cells formed a large proportion of cells in the high infiltration cluster, which correlated to a good prognosis. Differentially expressed genes (DEGs) extracted between two heterogeneous subtypes were used to further explore the underlying immune mechanism and to identify prognostic biomarkers. Functional enrichment analysis revealed that the DEGs were predominately related to some processes involved in activation and regulation of innate immune signaling. Using network analysis, we identified two modules in which genes were selected for further prognostic investigation. Validation by independent datasets revealed that CXCL9 and CXCL13 were good prognostic biomarkers for TNBC. We also performed comparisons between the above two genes and immune markers (CYT, APM, TILs, and TIS), as well as cell checkpoint marker expressions, and found a statistically significant correlation between them in both METABRIC and TCGA datasets. The potential of CXCL9 and CXCL13 to predict chemotherapy sensitivity was also evaluated. We found that the CXCL9 and CXCL13 were good predictors for chemotherapy and their expressions were higher in chemotherapy-responsive patients in contrast to those who were not responsive. In brief, immune infiltrate characterization on TNBC revealed heterogeneous subtypes with unique immune features allowed for the identification of informative and reliable characteristics representative of the local immune tumor microenvironment and were potential candidates to guide the management of TNBC patients.

Kinetic Modeling of DUSP Regulation in Herceptin-Resistant HER2-Positive Breast Cancer

BACKGROUND

HER2 (human epidermal growth factor 2)-positive breast cancer is an aggressive type of breast cancer characterized by the overexpression of the receptor-type protein tyrosine kinase HER2 or amplification of the HER2 gene. It is commonly treated by the drug trastuzumab (Herceptin), but resistance to its action frequently develops and limits its therapeutic benefit. Dual-specificity phosphatases (DUSPs) were previously highlighted as central regulators of HER2 signaling; therefore, understanding their role is crucial to designing new strategies to improve the efficacy of Herceptin treatment. We investigated whether inhibiting certain DUSPs re-sensitized Herceptin-resistant breast cancer cells to the drug. We built a series of kinetic models incorporating the key players of HER2 signaling pathways and simulating a range of inhibition intensities. The simulation results were compared to live tumor cells in culture, and showed good agreement with the experimental analyses. In particular, we observed that Herceptin-resistant DUSP16-silenced breast cancer cells became more responsive to the drug when treated for 72 h with Herceptin, showing a decrease in resistance, in agreement with the model predictions. Overall, we showed that the kinetic modeling of signaling pathways is able to generate predictions that assist experimental research in the identification of potential targets for cancer treatment.