High DNMT1 Expression in Stromal Fibroblasts Promotes Angiogenesis and Unfavorable Outcome in Locally Advanced Breast Cancer Patients

Bifunctional probe propelling multipath strand displacement amplification tandem CRISPR/Cas12a for ultrasensitive and robust assay of DNA methyltransferase activity

BACKGROUND

DNA methylation catalyzed by various DNA methyltransferases (DNA MTases) is one of the important epigenetic regulations in both eukaryotes and prokaryotes. Therefore, the detection of DNA MTase activity is a vital target and direction in the study of methylation-related diseases.

RESULTS

In this study, an ultrasensitive and robust strategy was developed for DNA MTase activity sensing based on bifunctional probe propelling multipath strand displacement amplification and CRISPR/Cas12a techniques. First, a bifunctional hairpin probe (bHpDNA) was designed instead of a conventional single-function probe. In the presence of DNA MTase, the bHpDNA was methylated and cleaved by a restriction endonuclease into two independent primers, both of which bind with the templates to trigger strand displacement amplification and produce the active DNA of CRISPR/Cas12a. Second, annealing-assisted binding instead of free diffusion adhesion was used to improve hybridization efficiency between the primers and templates. Finally, the CRISPR/Cas12a system was used to achieve fluorescence signal output to analyze DNA MTase activity. If targets were absent, there was no signal because no primers were released from the bHpDNA. To verify the reliability of the method, two key DNA MTases, Dam and M. SssI, were analyzed, and their limits of detection were 2.458 × 10-3 and 3.820 × 10-3 U/mL, respectively, which were lower than those of most reported fluorescence methods.

SIGNIFICANCE

This method was successfully used in the evaluation of DNA MTase inhibitors and the detection of DNA MTase activity in complex biological systems with good recoveries and relative standard deviation at low spiked concentrations (0.1-1 U/mL), which all indicate that this method is an ultrasensitive and robust strategy in DNA MTase activity assay and has great potential in biomedical and clinical detection.

DNMT1 rs2228611, rs2228612 and DNMT3A rs2276598, rs752208 Polymorphisms and Their Association with Breast Cancer Phenotype and Prognosis

Background and Objectives: Breast cancer is a leading cause of cancer-related deaths globally. This study investigates the impact of genetic polymorphisms in DNA methyltransferases (DNMT1 and DNMT3A) on breast cancer pathomorphology and patient prognosis. Specifically, we focused on DNMT1 polymorphisms rs2228611 and rs2228612 and DNMT3A polymorphisms rs2276598 and rs752208. Materials and Methods: Conducted at the Institute of Oncology of the Lithuanian University of Health Sciences, this study included 201 Lithuanian women with early-stage breast cancer. DNA was extracted from peripheral blood samples, and genotyping for the specified polymorphisms was performed using the PCR-RFLP assay. Statistical analyses were applied to evaluate associations between polymorphisms and clinicopathological characteristics. Results: The non-carriers of the DNMT1 rs2228611 G allele were less likely to be diagnosed at an older age, while the DNMT3A rs752208 T allele was linked to lower-grade tumors. Survival analysis indicated a potential relationship between DNMT3A rs752208 and overall survival, although no significant findings were observed in progression-free or metastasis-free survival. Conclusions: This study suggests that the DNMT1 and DNMT3A polymorphisms may influence breast cancer pathomorphology and prognosis. The DNMT1 rs2228611 G allele may be associated with earlier onset, and the DNMT3A rs752208 T allele might correlate with less aggressive tumors. These findings underscore the potential of DNMT gene polymorphisms as prognostic biomarkers in breast cancer, warranting further investigation with larger sample sizes.

Decoding tumor-fibrosis interplay: mechanisms, impact on progression, and innovative therapeutic strategies

Malignant tumors are a category of diseases that possess invasive and metastatic capabilities, with global incidence and mortality rates remaining high. In recent years, the pivotal role of fibrosis in tumor progression, drug resistance, and immune evasion has increasingly been acknowledged. Fibrosis enhances the proliferation, migration, and invasion of tumor cells by modifying the composition and structure of the extracellular matrix, thereby offering protection for immune evasion by tumor cells. The activation of cancer-associated fibroblasts (CAFs) plays a significant role in this process, as they further exacerbate the malignant traits of tumors by secreting a variety of cytokines and growth factors. Anti-fibrotic tumor treatment strategies, including the use of anti-fibrotic drugs and inhibition of fibrosis-related signaling pathways such as Transforming Growth Factor-β (TGF-β), have demonstrated potential in delaying tumor progression and improving the effectiveness of chemotherapy, targeted therapy, and immunotherapy. In the future, by developing novel drugs that target the fibrotic microenvironment, new therapeutic options may be available for patients with various refractory tumors.

Research progress of human key DNA and RNA methylation-related enzymes assay

Gene methylation-related enzymes (GMREs) are disfunction and aberrantly expressed in a variety of cancers, such as lung, gastric, and pancreatic cancers and have important implications for human health. Therefore，it is critical for early diagnosis and therapy of tumor to develop strategies that allow rapid and sensitive quantitative and qualitative detection of GMREs. With the development of modern analytical techniques and the application of various biosensors, there are numerous methods have been developed for analysis of GMREs. Therefore, this paper provides a systematic review of the strategies for level and activity assay of various GMREs including methyltransferases and demethylase. The detection methods mainly involve immunohistochemistry, colorimetry, fluorescence, chemiluminescence, electrochemistry, etc. Then, this review also addresses the coordinated role of various detection probes, novel nanomaterials, and signal amplification methods. The aim is to highlight potential challenges in the present field, to expand the analytical application of GMREs detection strategies, and to meet the urgent need for future disease diagnosis and intervention.

Epigenetic deregulation in breast cancer microenvironment: Implications for tumor progression and therapeutic strategies

Breast cancer comprises a substantial proportion of cancer diagnoses in women and is a primary cause of cancer-related mortality. While hormone-responsive cases generally have a favorable prognosis, the aggressive nature of triple-negative breast cancer presents challenges, with intrinsic resistance to established treatments being a persistent issue. The complexity intensifies with the emergence of acquired resistance, further complicating the management of breast cancer. Epigenetic changes, encompassing DNA methylation, histone and RNA modifications, and non-coding RNAs, are acknowledged as crucial contributors to the heterogeneity of breast cancer. The unique epigenetic landscape harbored by each cellular component within the tumor microenvironment (TME) adds great diversity to the intricate regulations which influence therapeutic responses. The TME, a sophisticated ecosystem of cellular and non-cellular elements interacting with tumor cells, establishes an immunosuppressive microenvironment and fuels processes such as tumor growth, angiogenesis, and extracellular matrix remodeling. These factors contribute to challenging conditions in cancer treatment by fostering a hypoxic environment, inducing metabolic stress, and creating physical barriers to drug delivery. This article delves into the complex connections between breast cancer treatment response, underlying epigenetic changes, and vital interactions within the TME. To restore sensitivity to treatment, it emphasizes the need for combination therapies considering epigenetic changes specific to individual members of the TME. Recognizing the pivotal role of epigenetics in drug resistance and comprehending the specificities of breast TME is essential for devising more effective therapeutic strategies. The development of reliable biomarkers for patient stratification will facilitate tailored and precise treatment approaches.

The importance of cancer-associated fibroblasts in targeted therapies and drug resistance in breast cancer

Cancer-associated fibroblasts (CAFs) play a substantial role in the tumor microenvironment, exhibiting a strong association with the advancement of various types of cancer, including breast, pancreatic, and prostate cancer. CAFs represent the most abundant mesenchymal cell population in breast cancer. Through diverse mechanisms, including the release of cytokines and exosomes, CAFs contribute to the progression of breast cancer by influencing tumor energy metabolism, promoting angiogenesis, impairing immune cell function, and remodeling the extracellular matrix. Moreover, CAFs considerably impact the response to treatment in breast cancer. Consequently, the development of interventions targeting CAFs has emerged as a promising therapeutic approach in the management of breast cancer. This article provides an analysis of the role of CAFs in breast cancer, specifically in relation to diagnosis, treatment, drug resistance, and prognosis. The paper succinctly outlines the diverse mechanisms through which CAFs contribute to the malignant behavior of breast cancer cells, including proliferation, invasion, metastasis, and drug resistance. Furthermore, the article emphasizes the potential of CAFs as valuable tools for early diagnosis, targeted therapy, treatment resistance, and prognosis assessment in breast cancer, thereby offering novel approaches for targeted therapy and overcoming treatment resistance in this disease.

Crosstalk and plasticity driving between cancer-associated fibroblasts and tumor microenvironment: significance of breast cancer metastasis

Cancer-associated fibroblasts (CAFs) are the most abundant stromal cell population in breast tumors. A functionally diverse population of CAFs increases the dynamic complexity of the tumor microenvironment (TME). The intertwined network of the TME facilitates the interaction between activated CAFs and breast cancer cells, which can lead to the proliferation and invasion of breast cells. Considering the special transmission function of CAFs, the aim of this review is to summarize and highlight the crosstalk between CAFs and breast cancer cells in the TME as well as the relationship between CAFs and extracellular matrix (ECM), soluble cytokines, and other stromal cells in the metastatic state. The crosstalk between cancer-associated fibroblasts and tumor microenvironment also provides a plastic therapeutic target for breast cancer metastasis. In the course of the study, the inhibitory effects of different natural compounds on targeting CAFs and the advantages of different drug combinations were summarized. CAFs are also widely used in the diagnosis and treatment of breast cancer. The cumulative research on this phenomenon supports the establishment of a targeted immune microenvironment as a possible breakthrough in the prevention of invasive metastasis of breast cancer.

The role of cancer-associated fibroblasts in breast cancer metastasis

Breast cancer deaths are primarily caused by metastasis. There are several treatment options that can be used to treat breast cancer. There are, however, a limited number of treatments that can either prevent or inhibit the spread of breast tumor metastases. Thus, novel therapeutic strategies are needed. Studies have increasingly focused on the importance of the tumor microenvironment (TME) in metastasis of breast cancer. As the most abundant cells in the TME, cancer-associated fibroblasts (CAFs) play important roles in cancer pathogenesis. They can remodel the structure of the extracellular matrix (ECM) and engage in crosstalk with cancer cells or other stroma cells by secreting growth factors, cytokines, and chemokines, as well as components of the ECM, which assist the tumor cells to invade through the TME and cause distant metastasis. Clinically, CAFs not only foster the initiation, growth, angiogenesis, invasion, and metastasis of breast cancer but also serve as biomarkers for diagnosis, therapy, and prediction of prognosis. In this review, we summarize the biological characteristics and subtypes of CAFs and their functions in breast cancer metastasis, focusing on their important roles in the diagnosis, prognosis, and treatment of breast cancer. Recent studies suggest that CAFs are vital partners of breast cancer cells that assist metastasis and may represent ideal targets for prevention and treatment of breast cancer metastasis.