Long Non-Coding RNA PVT1 Regulates the Resistance of the Breast Cancer Cell Line MDA-MB-231 to Doxorubicin via Nrf2

Targeting epigenetic and post-translational modifications of NRF2: key regulatory factors in disease treatment

Nuclear factor erythroid 2-related factor 2 (NRF2) is a key transcription factor involved in regulating cellular antioxidant defense and detoxification mechanisms. It mitigates oxidative stress and xenobiotic-induced damage by inducing the expression of cytoprotective enzymes, including HO-1 and NQO1. NRF2 also modulates inflammatory responses by inhibiting pro-inflammatory genes and mediates cell death pathways, including apoptosis and ferroptosis. Targeting NRF2 offers potential therapeutic avenues for treating various diseases. NRF2 is regulated through two principal mechanisms: post-translational modifications (PTMs) and epigenetic alterations. PTMs, including phosphorylation, ubiquitination, and acetylation, play a pivotal role in modulating NRF2's stability, activity, and subcellular localization, thereby precisely controlling its function in the antioxidant response. For instance, ubiquitination can lead to NRF2 degradation and reduced antioxidant activity, while deubiquitination enhances its stability and function. Epigenetic modifications, such as DNA methylation, histone modifications, and interactions with non-coding RNAs (e.g., MALAT1, PVT1, MIR4435-2HG, and TUG1), are essential for regulating NRF2 expression by modulating chromatin architecture and gene accessibility. This paper systematically summarizes the molecular mechanisms by which PTMs and epigenetic alterations regulate NRF2, and elucidates its critical role in cellular defense and disease. By analyzing the impact of PTMs, such as phosphorylation, ubiquitination, and acetylation, as well as DNA methylation, histone modifications, and non-coding RNA interactions on NRF2 stability, activity, and expression, the study reveals the complex cellular protection network mediated by NRF2. Furthermore, the paper explores how these regulatory mechanisms affect NRF2's roles in oxidative stress, inflammation, and cell death, identifying novel therapeutic targets and strategies. This provides new insights into the treatment of NRF2-related diseases, such as cancer, neurodegenerative disorders, and metabolic syndrome. This research deepens our understanding of NRF2's role in cellular homeostasis and lays the foundation for the development of NRF2-targeted therapies.

Regulation of immune-mediated chemoresistance in cancer by lncRNAs: an in-depth review of signaling pathways

Resistance to cancer therapies is increasingly recognized as being influenced by long non-coding RNAs (lncRNAs), which are pivotal in regulating cellular functions and gene expression. Elucidating the intricate relationship between lncRNAs and the mechanisms underlying drug resistance is critical for advancing effective therapeutic strategies. This study offers an in-depth review of the regulatory roles lncRNAs play in various signaling and immunological pathways implicated in cancer chemoresistance. lncRNA-mediated influence on drug resistance-related signaling pathways will be presented, including immune evasion mechanisms and other essential signaling cascades. Furthermore, the interplay between lncRNAs and the immune landscape will be dissected, illustrating their substantial impact on the development of chemoresistance. Overall, the potential of lncRNA-mediated signaling networks as a therapeutic strategy to combat cancer resistance has been highlighted. This review reiterates the fundamental role of lncRNAs in chemoresistance and proposes promising avenues for future research and the development of targeted therapeutic interventions.

Development of a tertiary lymphoid structure-based prognostic model for breast cancer: integrating single-cell sequencing and machine learning to enhance patient outcomes

Background

Breast cancer, a highly prevalent global cancer, poses significant challenges, especially in advanced stages. Prognostic models are crucial to enhance patient outcomes. Tertiary lymphoid structures (TLS) within the tumor microenvironment have been associated with better prognostic outcomes.

Methods

We analyzed data from 13 independent breast cancer cohorts, totaling over 9,551 patients. Using single-cell RNA sequencing and machine learning algorithms, we identified critical TLS-associated genes and developed a TLS-based predictive model. This model stratified patients into high and low-risk groups. Genomic alterations, immune infiltration, and cellular interactions within the tumor microenvironment were assessed.

Results

The TLS-based model demonstrated superior accuracy compared to traditional models, predicting overall survival. High TLS patients had higher tumor mutation burden and more chromosomal alterations, correlating with poorer prognosis. High-risk patients exhibited a significant depletion of CD4+ T cells, CD8+ T cells, and B cells, as evidenced by single-cell and bulk transcriptomic analyses. In contrast, immune checkpoint inhibitors demonstrated greater efficacy in low-risk patients, whereas chemotherapy proved more effective for high-risk individuals.

Conclusions

The TLS-based prognostic model is a robust tool for predicting breast cancer outcomes, highlighting the tumor microenvironment's role in cancer progression. It enhances our understanding of breast cancer biology and supports personalized therapeutic strategies.

Exploring extracellular RNA as drivers of chemotherapy resistance in cancer

Chemotherapy resistance (CR) represents one of the most important barriers to effective oncological therapy and often leads to ineffective intervention and unfavorable clinical prognosis. Emerging studies have emphasized the vital significance of extracellular RNA (exRNA) in influencing CR. This thorough assessment intends to explore the multifaceted contributions of exRNA, such as exosomal RNA, microRNAs, long non-coding RNAs, and circular RNAs, to CR in cancer. We discuss the mechanisms by which exRNA facilitates drug resistance, such as modulating gene expression, influencing the tumor microenvironment, and facilitating intercellular communication. Furthermore, we examine the potential of exRNA as prognostic factor for determining oncology treatment efficacy and their emerging role as therapeutic targets. Diagnostic and prognostic applications of exRNA biomarkers are considered, alongside current methodologies for their detection and quantification. Additionally, we review recent advances in exRNA-targeted therapies, highlighting ongoing clinical trials and therapeutic strategies aimed at overcoming chemoresistance. Despite the promise of exRNA research, several challenges remain, including technical limitations and the biological complexity of exRNA networks. This review underscores the importance of continued investigation into exRNA biology and its therapeutic potential, which in the future may provide new avenues for cancer treatment and tailored medical strategies. By elucidating the role of exRNA in CR, this article aims to provide a comprehensive resource for researchers and clinicians seeking to improve the effectiveness of carcinoma management approaches.

Advances in the Understanding of the Pathogenesis of Triple-Negative Breast Cancer

BACKGROUND

Triple-negative breast cancer (TNBC) is a heterogeneous disease characterized by high aggressiveness, high malignancy, and poor prognosis compared to other breast cancer subtypes.

OBJECTIVE

This review aims to explore recent advances in understanding TNBC and to provide new insights and potential references for clinical treatment.

METHODS

We examined current literature on TNBC to analyze molecular subtypes, genetic mutations, signaling pathways, mechanisms of drug resistance, and emerging therapies.

RESULTS

Findings highlight key aspects of TNBC's molecular subtypes, relevant mutations, and pathways, alongside emerging treatments that target drug resistance mechanisms.

CONCLUSION

These insights into TNBC pathogenesis may help guide future therapeutic strategies and improve clinical outcomes for patients with TNBC.

Targeted therapy approaches for epithelial-mesenchymal transition in triple negative breast cancer

Triple-negative breast cancer (TNBC) is distinguished by negative expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2), making it an aggressive subtype of breast cancer and contributes to 15-20% of the total incidence. TNBC is a diverse disease with various genetic variations and molecular subtypes. The tumor microenvironment involves multiple cells, including immune cells, fibroblast cells, extracellular matrix (ECM), and blood vessels that constantly interact with tumor cells and influence each other. The ECM undergoes significant structural changes, leading to induced cell proliferation, migration, adhesion, invasion, and epithelial-to-mesenchymal transition (EMT). The involvement of EMT in the occurrence and development of tumors through invasion and metastasis in TNBC has been a matter of concern. Therefore, EMT markers could be prognostic predictors and potential therapeutic targets in TNBC. Chemotherapy has been one of the primary options for treating patients with TNBC, but its efficacy against TNBC is still limited. Targeted therapy is a critical emerging option with enhanced efficacy and less adverse effects on patients. Various targeted therapy approaches have been developed based on the specific molecules and the signaling pathways involved in TNBC. These include inhibitors of signaling pathways such as TGF-β, Wnt/β-catenin, Notch, TNF-α/NF-κB and EGFR, as well as immune checkpoint inhibitors, such as pembrolizumab, 2laparib, and talazoparib have been widely explored. This article reviews recent developments in EMT in TNBC invasion and metastasis and potential targeted therapy strategies.

LGR4 attenuates MGP expression and suppresses EGFR activation-induced triple-negative breast cancer metastasis

Breast cancer has emerged as the most common cancer globally, with a significant reduction in overall survival rate after metastasis. Compared with other types of breast cancer, triple-negative breast cancer (TNBC) is more prone to metastasize, presenting substantial treatment challenges due to the lack of effective therapies. LGR4, which is highly expressed in breast cancer, has been shown to promote the proliferation and invasion of breast cancer cells. However, its specific role in TNBC remains unclear. In this study, we applied a multi-omics approach to explore the regulatory mechanism of LGR4 in TNBC metastasis. Our findings showed that LGR4 could regulate actin cytoskeletal through EGFR and curtail EGFR activation-induced TNBC metastasis by inhibiting MGP expression. These insights provide new perspectives on the role of LGR4 in breast cancer metastasis.

Allicin Overcomes Doxorubicin Resistance of Breast Cancer Cells by Targeting the Nrf2 Pathway

Breast cancer (BC) is a lethal disorder that threatens the life safety of the majority of females globally, with rising morbidity and mortality year by year. Doxorubicin is a cytotoxic anthracycline antibiotic that is widely used as one of the first-line chemotherapy agents for patients with BC. However, the efficacy of doxorubicin in the clinic is largely limited by its serious side effects and acquired drug resistance. Allicin (diallyl thiosulfinate), as the major component and key active compound present in freshly crushed garlic, has shown potential effects in suppressing chemotherapy resistance in various cancers. Our research aimed to explore the relationship between allicin and doxorubicin resistance in BC. To generate doxorubicin-resistant BC cell lines (MCF-7/DOX and MDA-MB-231/DOX), doxorubicin-sensitive parental cell lines MCF-7 and MDA-MB-231 were continuously exposed to stepwise increased concentrations of doxorubicin over a period of 6 months. CCK-8, colony formation, flow cytometry, RT-qPCR, and western blotting assays were performed to investigate the effects of allicin and/or doxorubicin treatment on the viability, proliferation and apoptosis and the expression of Nrf2, HO-1, phosphate AKT and AKT in doxorubicin-resistant BC cells. Our results showed that combined treatment of allicin with doxorubicin exhibited better effects on inhibiting the proliferation and enhancing the apoptosis of doxorubicin-resistant BC cells than treatment with allicin or doxorubicin alone. Mechanistically, allicin suppressed the levels of Nrf2, HO-1, and phosphate AKT in doxorubicin-resistant BC cells. Collectively, allicin improves the doxorubicin sensitivity of BC cells by inactivating the Nrf2/HO-1 signaling pathway.

Long non-coding RNA (lncRNA) PVT1 in drug resistance of cancers: Focus on pathological mechanisms

According to estimates, cancer will be the leading cause of death globally in 2022, accounting for 9.6 million deaths. At present, the three main therapeutic modalities utilized to treat cancer are radiation therapy, chemotherapy, and surgery. However, during treatment, tumor cells resistant to chemotherapy may arise. Drug resistance remains a major oppose since it often leads to therapeutic failure. Furthermore, the term "acquired drug resistance" describes the situation where tumor cells already display drug resistance before undergoing chemotherapy. However, little is still known about the basic mechanisms underlying chemotherapy-induced drug resistance. The development of new technologies and bioinformatics has led to the discovery of additional genes associated with drug resistance. Long noncoding RNA plasmacytoma variant translocation 1 (PVT1) has been linked to an increased risk of cancer, according to a growing body of research. Apart from biological functions associated with cell division, development, pluripotency, and cell cycle, lncRNA PVT1 contributes significantly to the regulation of various aspects of genome function, such as transcription, splicing, and epigenetics. The article will address the mechanism by which lncRNA PVT1 influences drug resistance in cancer cells.

Insights into the involvement of long non-coding RNAs in doxorubicin resistance of cancer

Doxorubicin is one of the most classical chemotherapeutic drugs for the treatment of cancer. However, resistance to the cytotoxic effects of doxorubicin in tumor cells remains a major obstacle. Aberrant expression of long non-coding RNAs (lncRNAs) has been associated with tumorigenesis and development via regulation of chromatin remodeling, transcription, and post-transcriptional processing. Emerging studies have also revealed that dysregulation of lncRNAs mediates the development of drug resistance through multiple molecules and pathways. In this review, we focus on the role and mechanism of lncRNAs in the progress of doxorubicin resistance in various cancers, which mainly include cellular drug transport, cell cycle disorder, anti-apoptosis, epithelial-mesenchymal transition, cancer stem cells, autophagy, tumor microenvironment, metabolic reprogramming and signaling pathways. This review is aimed to provide potential therapeutic targets for future cancer therapy, especially for the reversal of chemoresistance.

Exploiting Long Non-Coding RNAs and Circular RNAs as Pharmacological Targets in Triple-Negative Breast Cancer Treatment

Breast cancer is one of the most frequent causes of cancer death among women worldwide. In particular, triple-negative breast cancer (TNBC) represents the most aggressive breast cancer subtype because it is characterized by the absence of molecular targets, thus making it an orphan type of malignancy. The discovery of new molecular druggable targets is mandatory to improve treatment success. In that context, non-coding RNAs represent an opportunity for modulation of cancer. They are RNA molecules with apparently no protein coding potential, which have been already demonstrated to play pivotal roles within cells, being involved in different processes, such as proliferation, cell cycle regulation, apoptosis, migration, and diseases, including cancer. Accordingly, they could be used as targets for future TNBC personalized therapy. Moreover, the peculiar characteristics of non-coding RNAs make them reliable biomarkers to monitor cancer treatment, thus, to monitor recurrence or chemoresistance, which are the most challenging aspects in TNBC. In the present review, we focused on the oncogenic or oncosuppressor role of long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) mostly involved in TNBC, highlighting their mode of action and depicting their potential role as a biomarker and/or as targets of new non-coding RNA-based therapeutics.

Noncoding RNAs Controlling Oxidative Stress in Cancer

Mitochondria in cancer cells tend to overproduce reactive oxygen species (ROS), inducing a vicious cycle between mitochondria, ROS, genomic instability, and cancer development. The first part of this review deals with the role of noncoding RNAs in regulating mitochondrial ROS production and the expression of antioxidants in cancer cells, preventing the increase of ROS in the tumor microenvironment. In addition, cytotoxic T and natural killer cells release high levels of ROS, inducing cell death, while anti-immune regulatory T cells, tumor-associated M2 macrophages, and myeloid-derived suppressor cells, at least at the initial stage of tumor growth, release low levels of ROS supporting tumor growth. Therefore, this review's second part deals with noncoding RNAs' role in regulating the metabolic reprogramming of immune cells about ROS release. Furthermore, the enrichment of noncoding RNAs in microvesicles allows communication between cell types in a tumor and between a tumor and tumor-adjacent tissues. Therefore, the third part illustrates how noncoding RNA-containing microvesicles secreted by mesenchymal stem cells and primary tumor cells may primarily aid the shift of immune cells to a pro-oncogenic phenotype. Conversely, microvesicles released by tumor-adjacent tissues may have the opposite effect. Our review reveals that a specific noncoding RNA may affect oxidative stress by several mechanisms, which may have opposite effects on tumor growth. Furthermore, they may be involved in mechanisms other than regulating oxidative stress, which may level out their effects on oxidative stress and tumor growth. In addition, several noncoding RNAs might share a specific function, making it very unlikely that intervening with only one of these noncoding RNAs will block this particular mechanism. Overall, further validation of the interaction between noncoding RNAs about cancer types and stages of tumor development is warranted.

Potential Medical Use of Fullerenols After Two Decades of Oncology Research

Fullerenes are carbon molecules that are found in nature in various forms. They are composed of hexagonal and pentagonal rings that create closed structures. Almost 4 decades ago, fullerenes were identified in the form of C60 and C70, and following the award of the Nobel Prize in Chemistry for this discovery in 1996, many laboratories started working on their water-soluble derivatives that could be used in different industries, including pharmaceutical industries. One of the first fullerene forms that was the focus of different research groups was fullerenol, C60(OH)n (n  =  2-44). Both in-vitro and in-vivo studies have shown that polyhydroxylate fullerene derivatives can potentially be used as either antioxidative agents or cytostatics (depending on their co-administration, forms, and concentration/dose) in biological systems. The current review aimed to present a critical view of the potential applications and limitations of fullerenols in oncology, as understood from the past 2 decades of research.

lncRNA PVT1: a novel oncogene in multiple cancers

Long noncoding RNAs are involved in epigenetic gene modification, including binding to the chromatin rearrangement complex in pre-transcriptional regulation and to gene promoters in gene expression regulation, as well as acting as microRNA sponges to control messenger RNA levels in post-transcriptional regulation. An increasing number of studies have found that long noncoding RNA plasmacytoma variant translocation 1 (PVT1) plays an important role in cancer development. In this review of a large number of studies on PVT1, we found that PVT1 is closely related to tumor onset, proliferation, invasion, epithelial–mesenchymal transformation, and apoptosis, as well as poor prognosis and radiotherapy and chemotherapy resistance in some cancers. This review comprehensively describes PVT1 expression in various cancers and presents novel approaches to the diagnosis and treatment of cancer.

Knockdown of PVT1 Exerts Neuroprotective Effects against Ischemic Stroke Injury through Regulation of miR-214/Gpx1 Axis

Previous studies have reported that lncRNA PVT1 was closely related to ischemic stroke. Here, the role of PVT1 in ischemic stroke and the underlying mechanism were investigated. OGDR-stimulated PC12 cells were used to construct a cell model to mimic ischemic stroke. si-PVT1, miR-214 mimic, inhibitor, or the negative controls were transfected into PC12 cells prior to OGDR treatment. PVT1, miR-214, and Gpx1 expression was measured by qRT-PCR and western blotting assays. Cell proliferation and apoptosis were tested by CCK-8 assay and western blotting. The expression levels of inflammatory factors were determined by ELISA Kit. Results showed that PVT1 was increased significantly in OGDR PC12 cells. PVT1 knockdown significantly enhanced cell viability and attenuated cell apoptosis, ROS generation, and inflammation in OGDR PC12 cells. More importantly, PVT1 or Gpx1 was a target of miR-214. Mechanistically, PVT1 acted as a competing endogenous RNA of miR-214 to regulate the downstream gene Gpx1. In conclusion, PVT1 knockdown attenuated OGDR PC12 cell injury by modulating miR-214/Gpx1 axis. These findings offer a potential novel strategy for ischemic stroke therapy.

Long non-coding RNA PVT1: A promising chemotherapy and radiotherapy sensitizer

The long non-coding RNA (lncRNA) PVT1 was first found to activate variant translocations in the plasmacytoma of mice. Human lncPVT1 is located on chromosome 8q24.21, at the same locus as the well-known MYC oncogene. LncPVT1 has been found to promote the progression of various malignancies. Chemoresistance and radioresistance seriously affect tumor treatment efficacy and are associated with the dysregulation of physiological processes in cancer cells, including apoptosis, autophagy, stemness (for cancer stem cells, CSC), hypoxia, epithelial–mesenchymal transition (EMT), and DNA damage repair. Previous studies have also implicated lncPVT1 in the regulation of these physiological mechanisms. In recent years, lncPVT1 was found to modulate chemoresistance and radioresistance in some cancers. In this review, we discuss the mechanisms of lncPVT1-mediated regulation of cellular chemoresistance and radioresistance. Due to its high expression in malignant tumors and sensitization effect in chemotherapy and radiotherapy, lncPVT1 is expected to become an effective antitumor target and chemotherapy and radiotherapy sensitizer, which requires further study.

Molecular Mechanisms, Biomarkers and Emerging Therapies for Chemotherapy Resistant TNBC

Triple-negative breast cancer (TNBC) is associated with high recurrence rates, high incidence of distant metastases, and poor overall survival (OS). Taxane and anthracycline-containing chemotherapy (CT) is currently the main systemic treatment option for TNBC, while platinum-based chemotherapy showed promising results in the neoadjuvant and metastatic settings. An early arising of intrinsic or acquired CT resistance is common and represents the main hurdle for successful TNBC treatment. Numerous mechanisms were uncovered that can lead to the development of chemoresistance. These include cancer stem cells (CSCs) induction after neoadjuvant chemotherapy (NACT), ATP-binding cassette (ABC) transporters, hypoxia and avoidance of apoptosis, single factors such as tyrosine kinase receptors (EGFR, IGFR1), a disintegrin and metalloproteinase 10 (ADAM10), and a few pathological molecular pathways. Some biomarkers capable of predicting resistance to specific chemotherapeutic agents were identified and are expected to be validated in future studies for a more accurate selection of drugs to be employed and for a more tailored approach, both in neoadjuvant and advanced settings. Recently, based on specific biomarkers, some therapies were tailored to TNBC subsets and became available in clinical practice: olaparib and talazoparib for BRCA1/2 germline mutation carriers larotrectinib and entrectinib for neurotrophic tropomyosin receptor kinase (NTRK) gene fusion carriers, and anti-trophoblast cell surface antigen 2 (Trop2) antibody drug conjugate therapy for heavily pretreated metastatic TNBC (mTNBC). Further therapies targeting some pathologic molecular pathways, apoptosis, miRNAS, epidermal growth factor receptor (EGFR), insulin growth factor 1 receptor (IGF-1R), and androgen receptor (AR) are under investigation. Among them, phosphatidylinositol 3 kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) and EGFR inhibitors as well as antiandrogens showed promising results and are under evaluation in Phase II/III clinical trials. Emerging therapies allow to select specific antiblastics that alone or by integrating the conventional therapeutic approach may overcome/hinder chemoresistance.