miRNAs as biomarkers of therapeutic response to HER2-targeted treatment in breast cancer: A systematic review

Mechanism of miRNAs and miRNA-mRNA Regulatory Networks in Modulating Drug Resistance in HER2-Positive Breast Cancer: An Integrative Bioinformatics Approach

BACKGROUND

HER2-positive breast cancer is an aggressive subtype where innate/acquired resistance to targeted drugs remains a challenge. This study aims to uncover the underlying mechanisms of HER2 drug resistance through miRNA analysis and target identification.

METHODS

MiRNA datasets were systematically retrieved from the GEO database, and differential expression analysis was conducted for both miRNA and mRNA datasets. Functional analyses were also conducted to validate the identified miRNAs and assess their clinical relevance.

RESULTS

We identified 113 differentially expressed miRNAs (DEMs) and 923 target genes. Validation was performed using external mRNA datasets, and intersection with significant genes identified 110 overlapping genes associated with HER2 drug resistance. Further analyses included functional enrichment, construction of a protein-protein interaction (PPI) network, identification of key hub genes such as BCL2, FOS, and CXCR4, and assessment of clinical relevance through survival analysis and immunohistochemistry (IHC) assessments.

CONCLUSIONS

This integrative approach unveils a complex landscape of HER2 drug resistance in breast cancer, identifying crucial miRNAs, target genes, and significant pathways. The findings offer novel insights into the mechanisms governing drug resistance and highlight the potential for enhancing therapeutic strategies. Future studies are necessary for experimental validation to further explore the complex mechanisms involved.

Prognostic significance of malignant pleural effusions in patients with advanced luminal B breast cancer

BACKGROUND

Though the survival of breast cancer (BC) patients with malignant pleural effusion (MPE) has been studied, this has not been specifically studied in the luminal B subtype. Therefore, this study investigated the characteristics and survival of luminal B-BC patients presenting with MPE.

METHODS

We retrospectively analyzed 141 patients diagnosed with postoperative advanced Luminal B breast cancer, including 54 cases with MPE and 87 cases without MPE at the Tianjin Cancer Hospital from January 2012 to January 2015. We assessed the clinical characteristics between the groups.

RESULTS

The mean age of all patients was 47 years, with no significant difference between the two groups. Altogether, 29 (33%), 24 (28%), 28 (32%), 45 (52%), and 10 (11%) patients had lung, liver, bone, lymph node, and chest wall metastases, respectively. In addition. The difference in overall survival between the two groups was not significant (P>0.05). However, cox regression analysis showed that only the tumor clinical stage at initial diagnosis was related to short overall survival. Further, we conducted a subgroup analysis and found that the higher the clinical stage at initial diagnosis in age < 50 years patients, the shorter the overall survival, while age > 50 years patients was not. (P < 0.05).

CONCLUSIONS

There was no difference in the overall survival between luminal B-BC patients with MPE and those without. Clinical stages at initial diagnosis were an independent prognostic factor for age < 50 years luminal B BC with MPE overall survival. Our results may help clinicians make positive decisions regarding personalized treatment of luminal B-BC with MPE.

Investigation of the regulation of EGF signaling by miRNAs, delving into the underlying mechanism and signaling pathways in cancer

The EGF receptors (EGFRs) signaling pathway is essential for tumorigenesis and progression of cancer. Emerging evidence suggests that miRNAs are essential regulators of EGF signaling, influencing various pathway components and tumor behavior. This article discusses the underlying mechanisms and clinical implications of miRNA-mediated regulation of EGF signaling in cancer. miRNAs utilize multiple mechanisms to exert their regulatory effects on EGF signaling. They can target EGF ligands, including EGF and TGF-directly, inhibiting their expression and secretion. In addition, miRNAs can modulate EGF signaling indirectly by targeting EGF receptors, downstream signaling molecules, and transcription factors implicated in regulating the EGF pathway. These miRNAs can disrupt the delicate equilibrium of EGF signaling, resulting in aberrant activation and fostering tumor cell proliferation, survival, angiogenesis, and metastasis. The dysregulation of the expression of specific miRNAs has been linked to clinical outcomes in numerous types of cancer. Specific profiles of miRNA expression have been identified as prognostic markers, reflecting tumor characteristics, invasiveness, metastatic potential, and therapeutic response. These miRNAs can serve as potential therapeutic targets for interventions that modulate EGF signaling and improve patient outcomes. Understanding the intricate relationship between miRNAs and EGF signaling in cancer can transform cancer diagnosis, prognosis, and treatment. The identification of specific miRNAs involved in the regulation of the EGF pathway opens the door to the development of targeted therapies and personalized medicine approaches. In addition, miRNA-based interventions promise to overcome therapeutic resistance and improve the efficacy of existing treatments. miRNAs are crucial regulators of EGF signaling in cancer, affecting tumor behavior and clinical outcomes. Further research is required to decipher the complex network of miRNA-mediated EGF signaling regulation and translate these findings into clinically applicable strategies for enhanced cancer treatment.

Depicting Biomarkers for HER2-Inhibitor Resistance: Implication for Therapy in HER2-Positive Breast Cancer

HER2 (human epidermal growth factor receptor 2) is highly expressed in a variety of cancers, including breast, lung, gastric, and pancreatic cancers. Its amplification is linked to poor clinical outcomes. At the genetic level, HER2 is encoded by the ERBB2 gene (v-erb-b2 avian erythroblastic leukemia viral oncogene homolog 2), which is frequently mutated or amplified in cancers, thus spurring extensive research into HER2 modulation and inhibition as viable anti-cancer strategies. An impressive body of FDA-approved drugs, including anti-HER2 monoclonal antibodies (mAbs), antibody-drug conjugates (ADCs), and HER2-tyrosine kinase inhibitors (TKIs), have demonstrated success in enhancing overall survival (OS) and disease progression-free survival (PFS). Yet, drug resistance remains a persistent challenge and raises the risks of metastatic potential and tumor relapse. Research into alternative therapeutic options for HER2+ breast cancer therefore proves critical for adapting to this ever-evolving landscape. This review highlights current HER2-targeted therapies, discusses predictive biomarkers for drug resistance, and introduces promising emergent therapies-especially combination therapies-that are aimed at overcoming drug resistance in the context of HER2+ breast cancer.

HER2-targeted therapies in cancer: a systematic review

Abnormal alterations in human epidermal growth factor receptor 2 (HER2, neu, and erbB2) are associated with the development of many tumors. It is currently a crucial treatment for multiple cancers. Advanced in molecular biology and further exploration of the HER2-mediated pathway have promoted the development of medicine design and combination drug regimens. An increasing number of HER2-targeted drugs including specific monoclonal antibodies, tyrosine kinase inhibitors (TKIs), and antibody-drug conjugates (ADCs) have been approved by the U.S. Food and Drug Administration. The emergence of ADCs, has significantly transformed the treatment landscape for various tumors, such as breast, gastric, and bladder cancer. Classic monoclonal antibodies and novel TKIs have not only demonstrated remarkable efficacy, but also expanded their indications, with ADCs in particular exhibiting profound clinical applications. Moreover the concept of low HER2 expression signifies a breakthrough in HER2-targeted therapy, indicating that an increasing number of tumors and patients will benefit from this approach. This article, provides a comprehensive review of the underlying mechanism of action, representative drugs, corresponding clinical trials, recent advancements, and future research directions pertaining to HER2-targeted therapy.