The Long Non-Coding RNA SAMMSON Is a Regulator of Chemosensitivity and Metabolic Orientation in MCF-7 Doxorubicin-Resistant Breast Cancer Cells

Harnessing the potential of long non-coding RNAs in breast cancer: from etiology to treatment resistance and clinical applications

Breast cancer (BC) is the most common malignancy among women and a leading cause of cancer-related deaths of females worldwide. It is a complex and molecularly heterogeneous disease, with various subtypes that require different treatment strategies. Despite advances in high-resolution single-cell and multinomial technologies, distant metastasis and therapeutic resistance remain major challenges for BC treatment. Long non-coding RNAs (lncRNAs) are non-coding RNAs with more than 200 nucleotides in length. They act as competing endogenous RNAs (ceRNAs) to regulate post-transcriptional gene stability and modulate protein-protein, protein-DNA, and protein-RNA interactions to regulate various biological processes. Emerging evidence suggests that lncRNAs play essential roles in human cancers, including BC. In this review, we focus on the roles and mechanisms of lncRNAs in BC progression, metastasis, and treatment resistance, and discuss their potential value as therapeutic targets. Specifically, we summarize how lncRNAs are involved in the initiation and progression of BC, as well as their roles in metastasis and the development of therapeutic resistance. We also recapitulate the potential of lncRNAs as diagnostic biomarkers and discuss their potential use in personalized medicine. Finally, we provide lncRNA-based strategies to promote the prognosis of breast cancer patients in clinical settings, including the development of novel lncRNA-targeted therapies.

The oncogenic role of SAMMSON lncRNA in tumorigenesis: A comprehensive review with especial focus on melanoma

LncRNA Survival Associated Mitochondrial Melanoma Specific Oncogenic Non-coding RNA (SAMMSON) is located on human chromosome 3p13, and its expression is upregulated in several tumours, including melanoma, breast cancer, glioblastoma and liver cancer and has an oncogenic role in malignancy disorders. It has been reported that SAMMSON impacts metabolic regulation, cell proliferation, apoptosis, EMT, drug resistance, invasion and migration. Also, SAMMSON is involved in regulating several pathways such as Wnt, MAPK, PI3K, Akt, ERK and p53. SAMMSON is considered a potential diagnostic and prognostic biomarker in several types of cancer and a suitable therapeutic target. In addition, the highly expressed SAMMSON is closely associated with clinicopathological features of various cancers. SAMMSON has a significant role in regulating epigenetic processes by regulating histone protein or the status of DNA methylation. Herein for the first time, we comprehensively summarized the currently available SAMMSON, molecular regulatory pathways, and clinical significance. We believe that clarifying all the molecular aspects of this lncRNA can be a good guide for cancer studies in the future.

Breast Cancer Chemoresistance: Insights into the Regulatory Role of lncRNA

Long noncoding RNAs (lncRNAs) are a subclass of noncoding RNAs composed of more than 200 nucleotides without the ability to encode functional proteins. Given their involvement in critical cellular processes such as gene expression regulation, transcription, and translation, lncRNAs play a significant role in organism homeostasis. Breast cancer (BC) is the second most common cancer worldwide and evidence has shown a relationship between aberrant lncRNA expression and BC development. One of the main obstacles in BC control is multidrug chemoresistance, which is associated with the deregulation of multiple mechanisms such as efflux transporter activity, mitochondrial metabolism reprogramming, and epigenetic regulation as well as apoptosis and autophagy. Studies have shown the involvement of a large number of lncRNAs in the regulation of such pathways. However, the underlying mechanism is not clearly elucidated. In this review, we present the principal mechanisms associated with BC chemoresistance that can be directly or indirectly regulated by lncRNA, highlighting the importance of lncRNA in controlling BC chemoresistance. Understanding these mechanisms in deep detail may interest the clinical outcome of BC patients and could be used as therapeutic targets to overcome BC therapy resistance.

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.

Role of long non-coding RNAs in cancer: From subcellular localization to nanoparticle-mediated targeted regulation

Long non-coding RNAs (lncRNAs) are a class of RNA transcripts more than 200 nucleotides in length that play crucial roles in cancer development and progression. With the rapid development of high-throughput sequencing technology, a considerable number of lncRNAs have been identified as novel biomarkers for predicting the prognosis of cancer patients and/or therapeutic targets for cancer therapy. In recent years, increasing evidence has shown that the biological functions and regulatory mechanisms of lncRNAs are closely associated with their subcellular localization. More importantly, based on the important roles of lncRNAs in regulating cancer progression (e.g., growth, therapeutic resistance, and metastasis) and the specific ability of nucleic acids (e.g., siRNA, mRNA, and DNA) to regulate the expression of any target genes, much effort has been exerted recently to develop nanoparticle (NP)-based nucleic acid delivery systems for in vivo regulation of lncRNA expression and cancer therapy. In this review, we introduce the subcellular localization and regulatory mechanisms of various functional lncRNAs in cancer and systemically summarize the recent development of NP-mediated nucleic acid delivery for targeted regulation of lncRNA expression and effective cancer therapy.

Roles of Noncoding RNAs in Regulation of Mitochondrial Electron Transport Chain and Oxidative Phosphorylation

The mitochondrial electron transport chain (ETC) plays an essential role in energy production by inducing oxidative phosphorylation (OXPHOS) to drive numerous biochemical processes in eukaryotic cells. Disorders of ETC and OXPHOS systems are associated with mitochondria- and metabolism-related diseases, including cancers; thus, a comprehensive understanding of the regulatory mechanisms of ETC and OXPHOS systems is required. Recent studies have indicated that noncoding RNAs (ncRNAs) play key roles in mitochondrial functions; in particular, some ncRNAs have been shown to modulate ETC and OXPHOS systems. In this review, we introduce the emerging roles of ncRNAs, including microRNAs (miRNAs), transfer-RNA-derived fragments (tRFs), long ncRNAs (lncRNAs), and circular RNAs (circRNAs), in the mitochondrial ETC and OXPHOS regulation.

Comprehensive analysis of cuproptosis-related long non-coding RNA signature and personalized therapeutic strategy of breast cancer patients

Background

Breast cancer (BC) is considered to be one of the primary causes of cancer deaths in women. Cuproptosis was suggested to play an important role in tumor proliferation and tumor immune microenvironment. Therefore, an investigation was conducted to identify the relationship between cuproptosis-related long non-coding RNAs (lncRNAs) and BC prognosis.

Method

Based on The Cancer Genome Atlas (TCGA), nine cuproptosis-related lncRNAs were identified by Pearson's analysis and Cox regression analysis to create a cuproptosis-related lncRNA signature. Subsequently, patients with BC were divided into high-risk and low-risk groups. The Kaplan-Meier curves and a time-dependent receiver operating characteristic (ROC) analysis were employed to elucidate the predictive capability of the signature. After that, the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis was conducted by Gene Set Enrichment Analysis (GSEA), and the lncRNA-mRNA co-expression network was established by Cytoscape software. Furthermore, the ESTIMATE score was calculated, and the immune cell type component analysis was conducted. Eventually, immunotherapy response analysis was applied to identify the predictive power of cuproptosis-related lncRNAs to tumor immunotherapy response, including immune checkpoint gene expression levels, tumor mutational burden (TMB), and microsatellite instability (MSI).

Results

Patients with BC in the low-risk groups showed better clinical outcomes. The KEGG pathways in the high-risk groups were mainly enriched in immune response and immune cell activation. Furthermore, the ESTIMATE scores were higher in the low-risk groups, and their immune cell infiltrations were dramatically different from those of the high-risk groups. The low-risk groups were shown to have higher infiltration levels of CD8+ T cells and TMB-high status, resulting in better response to immunotherapies.

Conclusion

The findings of this study revealed that the nine-cuproptosis-related lncRNA risk score was an independent prognostic factor for BC. This signature was a potential predictor for BC immunotherapy response. What we found will provide novel insight into immunotherapeutic treatment strategies in BC.

The role of lncRNAs in the tumor microenvironment and immunotherapy of melanoma

Melanoma is one of the most lethal tumors with highly aggressive and metastatic properties. Although immunotherapy and targeted therapy have certain therapeutic effects in melanoma, a significant proportion of patients still have drug resistance after treatment. Recent studies have shown that long noncoding RNAs (lncRNAs) are widely recognized as regulatory factors in cancer. They can regulate numerous cellular processes, including cell proliferation, metastasis, epithelial-mesenchymal transition (EMT) progression and the immune microenvironment. The role of lncRNAs in malignant tumors has received much attention, whereas the relationship between lncRNAs and melanoma requires further investigation. Our review summarizes tumor suppressive and oncogenic lncRNAs closely related to the occurrence and development of melanoma. We summarize the role of lncRNAs in the immune microenvironment, immunotherapy and targeted therapy to provide new targets and therapeutic methods for clinical treatment.

Reactive Oxygen Species and Long Non-Coding RNAs, an Unexpected Crossroad in Cancer Cells

Long non-coding RNAs (lncRNA) have recently been identified as key regulators of oxidative stress in several malignancies. The level of reactive oxygen species (ROS) must be constantly regulated to maintain cancer cell proliferation and chemoresistance and to prevent apoptosis. This review will discuss how lncRNAs alter the ROS level in cancer cells. We will first describe the role of lncRNAs in the nuclear factor like 2 (Nrf-2) coordinated antioxidant response of cancer cells. Secondly, we show how lncRNAs can promote the Warburg effect in cancer cells, thus shifting the cancer cell’s “building blocks” towards molecules important in oxidative stress regulation. Lastly, we explain the role that lncRNAs play in ROS-induced cancer cell apoptosis and proliferation.