Emerging Therapies for Breast Cancer

UL16‑binding protein 1 is a significant prognostic and diagnostic marker for breast cancer

The aim of the present study was to investigate the association between UL16 binding protein 1 (ULBP1) and the prognosis of patients with and immune cell infiltration in breast cancer (BRCA). The mRNA data of BRCA and immune-related genes were extracted from The Cancer Genome Atlas and were analyzed using bioinformatics tools. Subsequently, the results obtained by bioinformatics were validated through the collection of clinical patient data at the Zibo Central hospital (Zibo, China). The difference in the expression of the ULBP1 gene between BRCA tissues and normal precancerous tissues was analyzed, followed by validation using immunohistochemistry. By combining clinical data from patients with BRCA, the prognostic and diagnostic significance of the ULBP1 gene in patients with BRCA was analyzed. Gene enrichment analysis was conducted to gain insight into the molecular mechanisms underlying the regulatory role of ULBP1 in BRCA by analyzing its related functions and signaling pathways. Furthermore, single sample gene set enrichment analysis (ssGSEA) and Spearman's correlation analysis were performed to explore the correlation between ULBP1 as a target gene related with tumor immune cell infiltration. The data revealed that ULBP1 is a target gene associated with immunity and the prognosis of patients with BRCA. Patients with BRCA with a high expression of ULBP1 had a poorer prognosis. ULBP1 expression correlated with progesterone receptor expression, estrogen receptor expression and histological type in patients with BRCA; thus, it may serve as an independent predictor for the overall survival rate of patients. Functional enrichment analysis revealed a significant co-expression between ULBP1 and ULBP2, ULBP3, retinoic acid early transcript 1K, as well as a significant enrichment of pathways associated with carcinogenesis and immune suppression. ssGSEA and Spearman's correlation analysis demonstrated significant correlations between ULBP1 expression and tumor immune cells, as well as immune checkpoints. Overall, the present study demonstrated that ULBP1 was associated with BRCA immunity and might serve as a prognostic and diagnostic biomarker for patients with BRCA. In addition, it might also be a potential target for the immunotherapy of BRCA.

Resistance to FOXM1 inhibitors in breast cancer is accompanied by impeding ferroptosis and apoptotic cell death

PURPOSE

Cancer treatments often become ineffective because of acquired drug resistance. To characterize changes in breast cancer cells accompanying development of resistance to inhibitors of the oncogenic transcription factor, FOXM1, we investigated the suppression of cell death pathways, especially ferroptosis, in FOXM1 inhibitor-resistant cells. We also explored whether ferroptosis activators can synergize with FOXM1 inhibitors and can overcome FOXM1 inhibitor resistance.

METHODS

In estrogen receptor-positive and triple-negative breast cancer cells treated with FOXM1 inhibitor NB73 and ferroptosis activators dihydroartemisinin and JKE1674, alone and in combination, we measured suppression of cell viability, motility, and colony formation, and monitored changes in gene and protein pathway expressions and mitochondrial integrity.

RESULTS

Growth suppression of breast cancer cells by FOXM1 inhibitors is accompanied by increased cell death and alterations in mitochondrial morphology and metabolic activity. Low doses of FOXM1 inhibitor strongly synergize with ferroptosis inducers to reduce cell viability, migration, colony formation, and expression of proliferation-related genes, and increase intracellular Fe+2 and lipid peroxidation, markers of ferroptosis. Acquired resistance to FOXM1 inhibition is associated with increased expression of cancer stem-cell markers and proteins that repress ferroptosis, enabling cell survival and drug resistance. Notably, resistant cells are still sensitive to growth suppression by low doses of ferroptosis activators, effectively overcoming the acquired resistance.

CONCLUSION

Delineating changes in viability and cell death pathways that can overcome drug resistance should be helpful in determining approaches that might best prevent or reverse resistance to therapeutic targeting of FOXM1 and ultimately improve patient clinical outcomes.

Integration of Bioinformatics and Machine Learning to Identify CD8+ T Cell-Related Prognostic Signature to Predict Clinical Outcomes and Treatment Response in Breast Cancer Patients

The incidence of breast cancer (BC) continues to rise steadily, posing a significant burden on the public health systems of various countries worldwide. As a member of the tumor microenvironment (TME), CD8+ T cells inhibit cancer progression through their protective role. This study aims to investigate the role of CD8+ T cell-related genes (CTRGs) in breast cancer patients.

METHODS

We assessed the abundance of CD8+ T cells in the TCGA and METABRIC datasets and obtained CTRGs through WGCNA. Subsequently, a prognostic signature (CTR score) was constructed from CTRGs screened by seven machine learning algorithms, and the relationship between the CTR score and TME, immunotherapy, and drug sensitivity was analyzed. Additionally, CTRGs' expression in different cells within TME was identified through single-cell analysis and spatial transcriptomics. Finally, the expression of CTRGs in clinical tissues was verified via RT-PCR.

RESULTS

The CD8+ T cell-related prognostic signature consists of two CTRGs. In the TCGA and METABRIC datasets, the CTR score appeared to be negatively linked to the abundance of CD8+ T cells, and BC patients with higher risk score show a worse prognosis. The low CTR score group exhibits higher immune infiltration levels, closely associated with inhibiting the tumor microenvironment. Compared with the high CTR score group, the low CTR score group shows better responses to chemotherapy and immune checkpoint therapy. Single-cell analysis and spatial transcriptomics reveal the heterogeneity of two CTRGs in different cells. Compared with the adjacent tissues, CD163L1 and KLRB1 mRNA are downregulated in tumor tissues.

CONCLUSIONS

This study establishes a robust CD8+ T cell-related prognostic signature, providing new insights for predicting the clinical outcomes and treatment responses of breast cancer patients.

Breast Cancer

Breast cancer kills hundreds of thousands of people every year. Rapid progress over the past two decades has increased our understanding of the genetic and environmental risk factors for disease. It has also shed light on drivers of tumor progression and the molecular landscape underpinning tumor heterogeneity, as well as the role of the microenvironment and the immune system. These strides forward should lead to more effective and tailored therapies for early- and late-stage patients.

Emerging strategy for the treatment of urothelial carcinoma: Advances in antibody-drug conjugates combination therapy

Urothelial carcinoma (UC) is a prevalent malignant tumor involving the urinary system. Although there are various treatment modalities, including surgery, chemotherapy, and immune checkpoint inhibitor (ICI) therapy, some patients experience disease recurrence and metastasis with poor prognosis and dismal long-term survival. Antibody-drug conjugates (ADCs), which combine the targeting ability of antibody drugs with the cytotoxicity of chemotherapeutic drugs, have recently emerged as a prominent research focus in the development of individualized precision cancer therapy. Although ADCs have improved the overall response rate in patients with UC, their effectiveness remains limited. Currently, ADC-based combination therapies, particularly ADC combined with ICIs, have demonstrated promising efficacy. This combination approach has advanced the treatment of UC, exhibiting the potential to become the standard first-line therapy for advanced UC in the future. This article reviewed clinical trials involving ADC-based combination therapy for UC and discussed the possible challenges and future perspectives to provide guidance for the clinical treatment of UC.

Targeting the oncogenic transcription factor FOXM1 to improve outcomes in all subtypes of breast cancer

FOXM1 (Forkhead box M1) is an oncogenic transcription factor that is greatly upregulated in breast cancer and many other cancers where it promotes tumorigenesis, and cancer growth and progression. It is expressed in all subtypes of breast cancer and is the factor most associated with risk of poor patient survival, especially so in triple negative breast cancer (TNBC). Thus, new approaches to inhibiting FOXM1 and its activities, and combination therapies utilizing FOXM1 inhibitors in conjunction with known cancer drugs that work together synergistically, could improve cancer treatment outcomes. Targeting FOXM1 might prove especially beneficial in TNBC where few targeted therapies currently exist, and also in suppressing recurrent advanced estrogen receptor (ER)-positive and HER2-positive breast cancers for which treatments with ER or HER2 targeted therapies that were effective initially are no longer beneficial. We present these perspectives and future directions in the context of what is known about FOXM1, its regulation, and its key roles in promoting cancer aggressiveness and metastasis, while being absent or very low in most normal non-regenerating adult tissues. We discuss new inhibitors of FOXM1 and highlight FOXM1 as an attractive target for controlling drug-resistant and difficult-to-suppress breast cancers, and how blocking FOXM1 might improve outcomes for patients with all subtypes of breast cancer.