Downregulation of long noncoding RNA HCP5 contributes to cisplatin resistance in human triple-negative breast cancer via regulation of PTEN expression

lncRNAs: New players of cancer drug resistance via targeting ABC transporters

Cancer drug resistance poses a significant obstacle to successful chemotherapy, primarily driven by the activity of ATP-binding cassette (ABC) transporters, which actively efflux chemotherapeutic agents from cancer cells, reducing their intracellular concentrations and therapeutic efficacy. Recent studies have highlighted the pivotal role of long noncoding RNAs (lncRNAs) in regulating this resistance, positioning them as crucial modulators of ABC transporter function. lncRNAs, once considered transcriptional noise, are now recognized for their complex regulatory capabilities at various cellular levels, including chromatin modification, transcription, and post-transcriptional processing. This review synthesizes current research demonstrating how lncRNAs influence cancer drug resistance by modulating the expression and activity of ABC transporters. lncRNAs can act as molecular sponges, sequestering microRNAs that would otherwise downregulate ABC transporter genes. Additionally, they can alter the epigenetic landscape of these genes, affecting their transcriptional activity. Mechanistic insights reveal that lncRNAs contribute to the activity of ABC transporters, thereby altering the efflux of chemotherapeutic drugs and promoting drug resistance. Understanding these interactions provides a new perspective on the molecular basis of chemoresistance, emphasizing the regulatory network of lncRNAs and ABC transporters. This knowledge not only deepens our understanding of the biological mechanisms underlying drug resistance but also suggests novel therapeutic strategies. In conclusion, the intricate interplay between lncRNAs and ABC transporters is crucial for developing innovative solutions to combat cancer drug resistance, underscoring the importance of continued research in this field.

Breast cancer drug resistance: Decoding the roles of Hippo pathway crosstalk

The most significant factors that lead to cancer-related death in breast cancer (BC) patients include drug resistance, migration, invasion, and metastasis. Several signaling pathways are involved in the development of BC. The different types of BC are initially sensitive to chemotherapy, and drug resistance can occur through multiple molecular mechanisms. Regardless of developing targeted Therapy, due to the heterogenic nature and complexity of drug resistance, it is a major clinical challenge with the low survival rate in BC patients. The deregulation of several signaling pathways, particularly the Hippo pathway (HP), is one of the most recent findings about the molecular mechanisms of drug resistance in BC, which are summarized in this review. Given that HP is one of the recent cancer research hotspots, this review focuses on its implication in BC drug resistance. Unraveling the different molecular basis of HP through its crosstalk with other signaling pathways, and determining the effectiveness of HP inhibitors can provide new insights into possible therapeutic strategies for overcoming chemoresistance in BC.

Decoding cell death signalling: Impact on the response of breast cancer cells to approved therapies

Breast cancer is a principal cause of cancer-related mortality in female worldwide. While many approved therapies have shown promising outcomes in treating breast cancer, understanding the intricate signalling pathways controlling cell death is crucial for optimizing the treatment outcome. A growing body of evidence has unveiled the aberrations in multiple cell death pathways across diverse cancer types, highlighting these pathways as appealing targets for therapeutic interventions. In this review, we provide a comprehensive overview of the current state of knowledge on the cell death signalling mechanisms with a particular focus on their impact on the response of breast cancer cells to approved therapies. Additionally, we discuss the potentials of combination therapies that exploit the synergy between approved drugs and therapeutic agents targeting modulators of cell death pathways.

Genomic Alterations Affecting Competitive Endogenous RNAs (ceRNAs) and Regulatory Networks (ceRNETs) with Clinical Implications in Triple-Negative Breast Cancer (TNBC)

The concept of competitive endogenous RNA regulation has brought on a change in the way we think about transcriptional regulation by miRNA-mRNA interactions. Rather than the relatively simple idea of miRNAs negatively regulating mRNA transcripts, mRNAs and other non-coding RNAs can regulate miRNAs and, therefore, broad networks of gene products through competitive interactions. While this concept is not new, its significant roles in and implications on cancer have just recently come to light. The field is now ripe for the extrapolation of technologies with a substantial clinical impact on cancer. With the majority of the genome consisting of non-coding regions encoding regulatory RNAs, genomic alterations in cancer have considerable effects on these networks that have been previously unappreciated. Triple-negative breast cancer (TNBC) is characterized by high mutational burden, genomic instability and heterogeneity, making this aggressive breast cancer subtype particularly relevant to these changes. In the past few years, much has been learned about the roles of competitive endogenous RNA network regulation in tumorigenesis, disease progression and drug response in triple-negative breast cancer. In this review, we present a comprehensive view of the new knowledge and future perspectives on competitive endogenous RNA networks affected by genomic alterations in triple-negative breast cancer. An overview of the competitive endogenous RNA (ceRNA) hypothesis and its bearing on cellular function and disease is provided, followed by a thorough review of the literature surrounding key competitive endogenous RNAs in triple-negative breast cancer, the genomic alterations affecting them, key disease-relevant molecular and functional pathways regulated by them and the clinical implications and significance of their dysregulation. New knowledge of the roles of these regulatory mechanisms and the current acceleration of research in the field promises to generate insights into the diagnosis, classification and treatment of triple-negative breast cancer through the elucidation of new molecular mechanisms, therapeutic targets and biomarkers.

SRSF1 inhibits ferroptosis and reduces cisplatin chemosensitivity of triple-negative breast cancer cells through the circSEPT9/GCH1 axis

Cisplatin (DDP) is a commonly used chemotherapeutic agent for triple negative breast cancer (TNBC), but its efficacy can be limited by chemoresistance. This study aimed to explore the functional mechanism of SR-rich splicing factor 1 (SRSF1) in DDP chemosensitivity of TNBC cells. Levels of SRSF1, circular RNA septin 9 (circSEPT9), and GTP cyclohydrolase-1 (GCH1) in TNBC cells, DDP-resistant cells, and normal cells were determined. Cell viability, half-maximal inhibitory concentration (IC50) value, and proliferation were evaluated. Ferroptosis was determined by assay kits (ferric ion/ROS/MDA/GSH) and Western blot assay (SLC7A11/ACSL4). The genetic binding was analyzed by RNA immunoprecipitation and RNA pull-down assays. SRSF1, circSEPT9, and GCH1 were upregulated in TNBC cells. SRSF1 downregulation reduced IC50 to DDP of parent and drug-resistant TNBC cells and inhibited cell viability and proliferation, meanwhile, the downregulation reduced GSH/SLC7A11 levels while elevated ferric ion/ROS/MDA/ACSL4 levels, promoting ferroptosis. SRSF1 bound to and upregulated circSEPT9 and circSEPT9 blocked the ubiquitination of GCH1, thereby increasing GCH1 protein level. Overexpression of circSEPT9 and GCH1 attenuated the DDP chemosensitivity of TNBC cells by inhibiting ferroptosis. This study is the first to report the role of SRSF1 inhibitors combined with chemotherapy in TNBC, which provides a promising strategy for the treatment of TNBC. SIGNIFICANCE: Cisplatin (DDP) is a commonly used chemotherapeutic agent for triple negative breast cancer (TNBC), but its efficacy can be limited by chemoresistance. This study aimed to unravel the molecular mechanism of SR-rich splicing factor 1 (SRSF1) in DDP chemosensitivity of TNBC cells.

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.

Roles of long noncoding RNA in triple-negative breast cancer

INTRODUCTION

Long noncoding RNAs (lncRNAs) play crucial roles in regulating various hallmarks in cancers. Triple-negative (Estrogen receptor, ER; Human epidermal growth factor receptor 2, HER2; Progesterone receptor, PR) breast cancer (TNBC) is the most aggressive form of breast cancers with a poor prognosis and no available molecular targeted therapy.

METHODS

We reviewed the current literature on the roles of lncRNAs in the pathogenesis, therapy resistance, and prognosis of patients with TBNC.

RESULTS

LncRNAs are associated with TNBC pathogenesis, therapy resistance, and prognosis. For example, lncRNAs such as small nucleolar RNA host gene 12 (SNHG12), highly upregulated in liver cancer (HULC) HOX transcript antisense intergenic RNA (HOTAIR), lincRNA-regulator of reprogramming (LincRNA-ROR), etc., are aberrantly expressed in TNBC and are involved in the pathogenesis of the disease. LncRNAs act as a decoy, scaffold, or sponge to regulate the expression of genes, miRNAs, and transcription factors associated with pathogenesis and progression of TNBC. Moreover, lncRNAs such as ferritin heavy chain 1 pseudogene 3 (FTH1P3), BMP/OP-responsive gene (BORG) contributes to the therapy resistance property of TNBC through activating ABCB1 (ATP-binding cassette subfamily B member 1) drug efflux pumps by increasing DNA repair capacity or by inducing signaling pathway involved in therapeutic resistance.

CONCLUSION

In this review, we outline the functions of various lncRNAs along with their molecular mechanisms involved in the pathogenesis, therapeutic resistance of TBNC. Also, the prognostic implications of lncRNAs in patients with TNBC is illustrated. Moreover, potential strategies targeting lncRNAs against highly aggressive TNBC is discussed in this review.

PD-1/PD-L1 Inhibitors Response in Triple-Negative Breast Cancer: Can Long Noncoding RNAs Be Associated?

As immune checkpoint inhibitors (ICI) emerge as a paradigm-shifting treatment option for patients with advanced or metastatic cancer, there is a growing demand for biomarkers that can distinguish which patients are likely to benefit. In the case of triple-negative breast cancer (TNBC), characterized by a lack of therapeutic targets, pembrolizumab approval for high-risk early-stage disease occurred regardless of PD-L1 status, which keeps the condition in a biomarker limbus. In this review, we highlight the participation of long non-coding RNAs (lncRNAs) in the regulation of the PD-1/PD-L1 pathway, as well as in the definition of prognostic immune-related signatures in many types of tumors, aiming to shed light on molecules that deserve further investigation for a potential role as biomarkers. We also conducted a bioinformatic analysis to investigate lncRNAs already investigated in PD-1/PDL-1 pathways in other cancer types, considering the TNBC molecular context. In this sense, from the generated data, we evidence here two lncRNAs, UCA1 and HCP5, which have not yet been identified in the context of the tumoral immune response in breast cancer. These candidates can be further explored to verify their use as biomarkers for ICI response. In this article, we present an updated review regarding the use of lncRNA as biomarkers of response to ICI, highlighting the versatility of using these molecules.

Progress in investigating the relationship between Schlafen5 genes and malignant tumors

The Schlafen5(SLFN5)gene belongs to the third group of the Schlafen protein family. As a tumor suppressor gene, SLFN5 plays a pivotal role in inhibiting tumor growth, orchestrating cell cycle regulation, and modulating the extent of cancer cell infiltration and metastasis in various malignancies. However, the high expression of SLFN 5 in some tumors was positively correlated with lymph node metastasis, tumor stage, and tumor grade. This article endeavors to elucidate the reciprocal relationship between the SLFN5 gene and malignant tumors, thereby enhancing our comprehension of the intricate mechanisms underlying the SLFN5 gene and its implications for the progression, invasive potential, and metastatic behavior of malignant tumors. At the same time, this paper summarizes the basis of SLFN 5 as a new biomarker of tumor diagnosis and prognosis, and provides new ideas for the target treatment of tumor.

Functional impact of non-coding RNAs in high-grade breast carcinoma: Moving from resistance to clinical applications: A comprehensive review

Despite the recent advances in cancer therapy, triple-negative breast cancers (TNBCs) are the most relapsing cancer sub-type. It is partly due to their propensity to develop resistance against the available therapies. An intricate network of regulatory molecules in cellular mechanisms leads to the development of resistance in tumors. Non-coding RNAs (ncRNAs) have gained widespread attention as critical regulators of cancer hallmarks. Existing research suggests that aberrant expression of ncRNAs modulates the oncogenic or tumor suppressive signaling. This can mitigate the responsiveness of efficacious anti-tumor interventions. This review presents a systematic overview of biogenesis and down streaming molecular mechanism of the subgroups of ncRNAs. Furthermore, it explains ncRNA-based strategies and challenges to target the chemo-, radio-, and immunoresistance in TNBCs from a clinical standpoint.

Downregulation of AC092894.1 promotes oxaliplatin resistance in colorectal cancer via the USP3/AR/RASGRP3 axis

BACKGROUND

Oxaliplatin resistance is a complex process and has been one of the most disadvantageous factors and indeed a confrontation in the procedure of colorectal cancer. Recently, long non-coding RNAs (lncRNAs) have emerged as novel molecules for the treatment of chemoresistance, but the specific molecular mechanisms mediated by them are poorly understood.

METHODS

The lncRNAs associated with oxaliplatin resistance were screened by microarray. lncRNA effects on oxaliplatin chemoresistance were then verified by gain- and loss-of-function experiments. Finally, the potential mechanism of AC092894.1 was explored by RNA pull-down, RIP, and Co-IP experiments.

RESULTS

AC092894.1 representation has been demonstrated to be drastically downregulated throughout oxaliplatin-induced drug-resistant CRC cells. In vivo and in vitro experiments revealed that AC092894.1 functions to reverse chemoresistance. Studies on the mechanism suggested that AC092894.1 served as a scaffold molecule that mediated the de-ubiquitination of AR through USP3, thereby increasing the transcription of RASGRP3. Finally, sustained activation of the MAPK signaling pathway induced apoptosis in CRC cells.

CONCLUSIONS

In conclusion, this study identified AC092894.1 as a suppressor of CRC chemoresistance and revealed the idea that targeting the AC092894.1/USP3/AR/RASGRP3 signaling axis is a novel option for the treatment of oxaliplatin resistance.

Metformin and long non-coding RNAs in breast cancer

Breast cancer (BC) is the second most common cancer and cause of death in women. In recent years many studies investigated the association of long non-coding RNAs (lncRNAs), as novel genetic factors, on BC risk, survival, clinical and pathological features. Recent studies also investigated the roles of metformin treatment as the firstline treatment for type 2 diabetes (T2D) played in lncRNAs expression/regulation or BC incidence, outcome, mortality and survival, separately. This comprehensive study aimed to review lncRNAs associated with BC features and identify metformin-regulated lncRNAs and their mechanisms of action on BC or other types of cancers. Finally, metformin affects BC by regulating five BC-associated lncRNAs including GAS5, HOTAIR, MALAT1, and H19, by several molecular mechanisms have been described in this review. In addition, metformin action on other types of cancers by regulating ten lncRNAs including AC006160.1, Loc100506691, lncRNA-AF085935, SNHG7, HULC, UCA1, H19, MALAT1, AFAP1-AS1, AC026904.1 is described.

DSCR9/miR-21-5p axis inhibits pancreatic cancer proliferation and resistance to gemcitabine via BTG2 signaling

The outcome of pancreatic adenocarcinoma (PAAD) patients is poor, given resistance to gemcitabine. Long noncoding RNA (lncRNA) has been implicated in the carcinogenesis of pancreatic cancer; however, its function and mechanism in PAAD resistance to gemcitabine (GEM) are yet unknown. Herein, we demonstrate that lncRNA DSCR9 is significantly reduced in PAAD in vitro and in vivo. CCK-8, BrdU and flow cytometry assays show that overexpression of DSCR9 markedly suppresses pancreatic cancer cell proliferation and invasion, and promotes apoptosis under gemcitabine treatment. BTG2 acts as a tumor suppressor by reducing the proliferation and invasion of pancreatic cancer cells and increasing gemcitabine-induced apoptosis. Immunofluorescence (IF) staining combined with fluorescence in situ hybridization (FISH) of pancreatic cancer tissues shows that DSCR9 and BTG2 are both increased in pancreatic cancer tissues. Luciferase assay shows that miR-21-5p simultaneously binds to DSCR9 and 3'UTR of BTG2; DSCR9 relieves miR-21-5p-induced inhibition of BTG2 by competing with BTG2 for miR-21-5p binding. Overexpression of miR-21-5p enhances the invasiveness of pancreatic cancer cells by promoting cancer cell proliferation and invasion and attenuating gemcitabine-induced apoptosis. Overexpression of miR-21-5p attenuates the effect of DSCR9 overexpression on BTG2 expression and invasiveness of pancreatic cancer cells. Finally, miR-21-5p expression is increased, while BTG2 expression is decreased in pancreatic cancer tissues. miR-21-5p is negatively correlated with DSCR9 and BTG2. In conclusion, the DSCR9/miR-21-5p/BTG2 axis modulates pancreatic cancer proliferation, invasion, and gemcitabine resistance.

Roles and Mechanisms of Long Non-Coding RNAs in Breast Cancer

Breast cancer is a major health threat and the second leading cause of cancer-related deaths in women worldwide. The detailed mechanisms involved in the initiation and progression of breast cancer remain unclear. In recent years, amounting evidence indicated that long non-coding RNAs (lncRNAs) played crucial roles in regulating various biological processes and malignancy tumors, including breast cancer. In this review, we briefly introduce the functions and underlying mechanisms by which lncRNAs are involved in breast cancer. We summarize the roles of the lncRNAs in regulating malignant behaviors of breast cancer, such as cell proliferation, migration and invasion, epithelial-mesenchymal transition (EMT), apoptosis, and drug resistance. Additionally, we also briefly summarize the roles of circular RNAs (circRNAs) in breast cancer carcinogenesis.

Non-coding RNAs, another side of immune regulation during triple-negative breast cancer

Triple-negative breast cancer (TNBC) is considered about 12-24 % of all breast cancer cases. Patients experience poor overall survival, high recurrence rate, and distant metastasis compared to other breast cancer subtypes. Numerous studies have highlighted the crucial roles of non-coding RNAs (ncRNAs) in carcinogenesis and proliferation, migration, and metastasis of tumor cells in TNBC. Recent research has demonstrated that long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) play a role in the regulation of the immune system by affecting the tumor microenvironment, the epithelial-mesenchymal transition, the regulation of dendritic cells and myeloid-derived stem cells, and T and B cell activation and differentiation. Immune-related miRNAs and lncRNAs, which have been established as predictive markers for various cancers, are strongly linked to immune cell infiltration and could be a viable therapeutic target for TNBC. In the current review, we discuss the recent updates of ncRNAs, including miRNAs and lncRNAs in TNBC, including their biogenesis, target genes, and biological function of their targets, which are mostly involved in the immune response.

Emerging roles of long noncoding RNAs in chemoresistance of pancreatic cancer

Pancreatic cancer is one of the most common causes of cancer death in the world due to the lack of early symptoms, metastasis occurrence and chemoresistance. Therefore, early diagnosis by detection of biomarkers, blockade of metastasis, and overcoming chemoresistance are the effective strategies to improve the survival of pancreatic cancer patients. Accumulating evidence has revealed that long noncoding RNA (lncRNA) and circular RNAs (circRNAs) play essential roles in modulating chemosensitivity in pancreatic cancer. In this review article, we will summarize the role of lncRNAs in drug resistance of pancreatic cancer cells, including HOTTIP, HOTAIR, PVT1, linc-ROR, GAS5, UCA1, DYNC2H1-4, MEG3, TUG1, HOST2, HCP5, SLC7A11-AS1 and CASC2. We also highlight the function of circRNAs, such as circHIPK3 and circ_0000284, in regulation of drug sensitivity of pancreatic cancer cells. Moreover, we describe a number of compounds, including curcumin, genistein, resveratrol, quercetin, and salinomycin, which may modulate the expression of lncRNAs and enhance chemosensitivity in pancreatic cancers. Therefore, targeting specific lncRNAs and cicrRNAs could contribute to reverse chemoresistance of pancreatic cancer cells. We hope this review might stimulate the studies of lncRNAs and cicrRNAs, and develop the new therapeutic strategy via modulating these noncoding RNAs to promote chemosensitivity of pancreatic cancer cells.

Long Noncoding RNA HCP5 Contributes to Nasopharyngeal Carcinoma Progression by Targeting MicroRNA-128-3p

Aim

To determine the role and underlying mechanism of lncRNA HCP5 in nasopharyngeal carcinoma (NPC).

Method

The expression of HCP5 and miR-128-3p was assessed by qRT-PCR. CCK-8, EdU staining, and transwell were performed to determine cell progression. A nude mouse xenograft tumor model was carried out to detect the role of HCP5 in vivo. The luciferase assay was performed to confirm the function between lncRNA HCP5 and miR-128-3p.

Results

The increased level of HCP5 was observed in NPC tissues. Silencing of HCP5 prevented tumor progression in vitro and in vivo. The luciferase assay verified that HCP5 could bind with miR-128-3p. Furthermore, forced expression of miR-128-3p could prevent the function of HCP5 on NPC cells.

Conclusion

lncRNA HCP5 could regulate NPC cell progression via sponging miR-128-3p, which might serve as a potential therapy target of NPC.

Establishment of a Cell Necroptosis Index to Predict Prognosis and Drug Sensitivity for Patients With Triple-Negative Breast Cancer

Background: Necroptosis has been an alternatively identified mechanism of programmed cancer cell death, which plays a significant role in cancer. However, research about necroptosis-related long noncoding RNAs (lncRNAs) in cancer are still few. Moreover, the potentially prognostic value of necroptosis-related lncRNAs and their correlation with the immune microenvironment remains unclear. The present study aimed to explore the potential prognostic value of necroptosis-related lncRNAs and their relationship to immune microenvironment in triple-negative breast cancer (TNBC).

Methods: The RNA expression matrix of patients with TNBC was obtained from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) databases. Finally, 107 patients of GSE58812, 159 patients of TCGA, and 143 patients of GSE96058 were included. Necroptosis-related lncRNAs were screened by Cox regression and Pearson correlation analysis with necroptosis-related genes. By LASSO regression analysis, nine necroptosis-related lncRNAs were employed, and a cell necroptosis index (CNI) was established; then, we evaluated its prognostic value, clinical significance, pathways, immune infiltration, and chemotherapeutics efficacy.

Results: Based on the CNI value, the TNBC patients were divided into high- and low-CNI groups, and the patients with high CNI had worse prognosis, more lymph node metastasis, and larger tumor (p < 0.05). The receiver operating characteristic (ROC) analysis showed that the signature performed well. The result of the infiltration proportion of different immune cell infiltration further explained that TNBC patients with high CNI had low immunogenicity, leading to poor therapeutic outcomes. Moreover, we found significant differences of the IC50 values of various chemotherapeutic drugs in the two CNI groups, which might provide a reference to make a personalized chemotherapy for them.

Conclusion: The novel prognostic marker CNI could not only precisely predict the survival probability of patients with TNBC but also demonstrate a potential role in antitumor immunity and drug sensitivity.

The Mechanisms of lncRNA-Mediated Multidrug Resistance and the Clinical Application Prospects of lncRNAs in Breast Cancer

Simple Summary

Multidrug resistance (MDR) is a major cause of breast cancer (BC) chemotherapy failure. Long noncoding RNAs (lncRNAs) have been shown closely related to the chemoresistance of BC. In this work, the mechanisms of lncRNA-mediated MDR in BC were elaborated from eight sections, including apoptosis, autophagy, DNA repair, cell cycle, drug efflux, epithelial-mesenchymal transition, epigenetic modification and the tumor microenvironment. Additionally, we also discuss the clinical significance of lncRNAs, which may be biomarkers for diagnosis, therapy and prognosis.

Abstract

Breast cancer (BC) is a highly heterogeneous disease and presents a great threat to female health worldwide. Chemotherapy is one of the predominant strategies for the treatment of BC; however, multidrug resistance (MDR) has seriously affected or hindered the effect of chemotherapy. Recently, a growing number of studies have indicated that lncRNAs play vital and varied roles in BC chemoresistance, including apoptosis, autophagy, DNA repair, cell cycle, drug efflux, epithelial-mesenchymal transition (EMT), epigenetic modification and the tumor microenvironment (TME). Although thousands of lncRNAs have been implicated in the chemoresistance of BC, a systematic review of their regulatory mechanisms remains to be performed. In this review, we systematically summarized the mechanisms of MDR and the functions of lncRNAs mediated in the chemoresistance of BC from the latest literature. These findings significantly enhance the current understanding of lncRNAs and suggest that they may be promising prognostic biomarkers for BC patients receiving chemotherapy, as well as therapeutic targets to prevent or reverse chemoresistance.

The functional significance and cross-talk of non-coding RNAs in triple negative and quadruple negative breast cancer

One of the leading causes of cancer-related deaths worldwide is breast cancer, among which triple-negative breast cancer (TNBC) is the most malignant and lethal subtype. This cancer accounts for 10-20% of all breast cancer deaths. Proliferation, tumorigenesis, and prognosis of TNBC are affected when the androgen receptor (AR) is not expressed, and it is classified as quadruple negative breast cancer (QNBC). Non-coding RNAs, such as microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), play a significant role in tumorigenesis by virtue of their oncogenic and tumor-suppressive properties. To regulate tumorigenesis, miRNAs interact with their target mRNAs and modulate their expression, whereas lncRNAs can either act alone or interact with miRNAs or other molecules through various signaling pathways. Conversely, circRNAs regulate tumorigenesis by acting as miRNA sponges predominantly. Recently, non-coding RNAs were studied comprehensively for their roles in tumor proliferation, progression, and metastasis. As a result of existing studies and research progress, non-coding RNAs have been implicated in TNBC, necessitating their use as biomarkers for future diagnostic applications. In this review, the non-coding RNAs are explicitly implicated in the regulation of breast cancer, and their cross-talk between TNBC and QNBC is also discussed.

Identification of a Novel Immune-Related lncRNA CTD-2288O8.1 Regulating Cisplatin Resistance in Ovarian Cancer Based on Integrated Analysis

Ovarian cancer (OC) is the most lethal gynecological malignancy, in which chemoresistance is a crucial factor leading to the poor prognosis. Recently, immunotherapy has brought new light for the treatment of solid tumors. Hence, as a kind of immunologically active cancer, it is reasonably necessary to explore the potential mechanism between immune characteristics and cisplatin resistance in OC. Our study focused on the important role of cisplatin resistance-related lncRNAs on mediating the OC tumor immune microenvironment (TIME) using an integrative analysis based on the Cancer Genome Atlas (TCGA) database. First, the cisplatin resistance-related differentially expressed lncRNAs (DELs) and mRNAs (DEMs) were preliminarily screened to construct a DEL–DEM co-expression network. Next, the protein–protein interaction (PPI) network and pivot analysis were performed to reveal the relevance of these lncRNAs with tumor immune response. Second, the novel lncRNA CTD-2288O8.1 was identified as a key gene for the OC cisplatin resistance formation by qRT-PCR and survival analysis. Gain- and loss-of-function assays (Cell Counting Kit-8 (CCK-8) assay, wound-healing scratch assay, transwell assay, and colony formation assay) further verified the activity of CTD-2288O8.1 in OC progression as well. Third, gene set enrichment analysis (GSEA) was applied along with the correlation analyses of CTD-2288O8.1 with ImmuneScore, tumor-infiltrating immune cells (TICs), and immune inhibitory checkpoint molecules, illustrating that CTD-2288O8.1 was strongly associated with the TIME and has the potential to predict the effect of OC immunotherapy. In addition, basic experiments demonstrated that the expression of CTD-2288O8.1 impacted the EGFR/AKT signal pathway activity of OC tumor cells. Of greater significance, it promoted the M2 polarization of macrophage, which is a type of the most important components of the TIME in solid tumor. Taking together, our study revealed cisplatin resistance-related lncRNAs closely linked with tumor immunity in OC, underscoring the potential mechanism of the TIME in conferring cisplatin resistance, which provided the research basis for further clinical treatment. CTD-2288O8.1 was identified to mediate cisplatin resistance and affect the response of immunotherapy, which could serve as a promising biomarker for guiding clinical treatment and improving prognosis in OC.

Noncoding RNAs in triple negative breast cancer: Mechanisms for chemoresistance

Triple-negative breast cancer (TNBC) is the most aggressive subtype among breast cancers with high recurrence and this condition is partly due to chemoresistance. Therefore, fully understanding the mechanism of TNBC-resistance is the key to overcoming chemoresistance, which will be an effective strategy for TNBC therapy. Various potential mechanisms involved in the chemoresistance of TNBC have been investigated and indicated that noncoding RNAs (ncRNAs) especially microRNAs (miRNAs), long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs) take part in most TNBC resistance. The ncRNA-induced chemoresistance process is involved in the alteration of many activities. here, we mainly summarize the mechanisms of ncRNAs in the chemoresistance of TNBC and discuss the potential clinical application of ncRNAs in the treatment of TNBC, indicating that targeting ncRNAs might be a promising strategy for resensitization to chemotherapies.

LncRNA HCP5 as a potential therapeutic target and prognostic biomarker for various cancers: a meta‑analysis and bioinformatics analysis

BACKGROUND

Accumulating studies indicated that dysregulated long non-coding RNA human histocompatibility leukocyte antigen (HLA) Complex P5 (HCP5) may functions as an potential prognostic predictor in multiple cancers. This meta-analysis was performed to systematically collect studies and conduct an evidence-based evaluation of the prognostic role of HCP5 in malignancies.

METHODS

Four databases (PubMed, Web of Science, Embase and Cochrane library) were comprehensively retrieved from their initiation date to November 9, 2021. Hazard ratio (HR) or odds ratio (OR) with 95% confidence interval (CI) were used to assess the associations between the expression level of HCP5 and prognosis or clinical characteristics. Moreover, results were validated by Gene Expression Profiling Interactive Analysis 2 (GEPIA2) and the National Genomics Data Center (NGDC). Subsequently, the molecular mechanism of HCP5 was predicted based on MEM and StarBase databases. The study protocol was registered at PROSPERO (ID: CRD42021274208).

RESULTS

9 studies, containing 641 patients, were included in this meta-analysis. Our results revealed that HCP5 overexpression was associated with poor overall survival (OS), tumor type, histological differentiation, and lymph node metastasis in most cancers, but was not associated with age, gender and tumor size; down-regulation of HCP5 was associated with worse OS, advanced tumor stage, positive distal metastasis and lymph node metastasis in skin cutaneous melanoma (SKCM). HCP5 was significantly up-regulated in four cancers and down-regulated in SKCM, which was validated by the GEPIA2 cohort. HCP5 expression in various types of cancer was also verified in NGDC. Further functional prediction revealed that HCP5 may participate in some cancer-related pathways.

CONCLUSION

There is a significantly association between dysregulation of HCP5 and both prognosis and clinicopathological features in various cancers. HCP5 may be functions as a novel potential prognostic biomarker and therapeutic target in multiple human cancers.

lncRNA and breast cancer: Progress from identifying mechanisms to challenges and opportunities of clinical treatment

Breast cancer is a malignant tumor that has a high mortality rate and mostly occurs in women. Although significant progress has been made in the implementation of personalized treatment strategies for molecular subtypes in breast cancer, the therapeutic response is often not satisfactory. Studies have reported that long non-coding RNAs (lncRNAs) are abnormally expressed in breast cancer and closely related to the occurrence and development of breast cancer. In addition, the high tissue and cell-type specificity makes lncRNAs particularly attractive as diagnostic biomarkers, prognostic factors, and specific therapeutic targets. Therefore, an in-depth understanding of the regulatory mechanisms of lncRNAs in breast cancer is essential for developing new treatment strategies. In this review, we systematically elucidate the general characteristics, potential mechanisms, and targeted therapy of lncRNAs and discuss the emerging functions of lncRNAs in breast cancer. Additionally, we also highlight the advantages and challenges of using lncRNAs as biomarkers for diagnosis or therapeutic targets for drug resistance in breast cancer and present future perspectives in clinical practice.

LncRNA-HAGLR motivates triple negative breast cancer progression by regulation of WNT2 via sponging miR-335-3p

Background: Triple negative breast cancer (TNBC) is a group of highly heterogeneous mixed breast cancer at the level of gene expression profile. Therefore, it is of great clinical significance to explore the molecular mechanism of TNBC and find a targeted therapeutic approach from the molecular level.

Methods: Long non-coding RNA (lncRNA) HAGLR expression level was measured by and qRT-PCR in TNBC tissues and cell lines. EdU, MTT, wound healing and Transwell assays were performed to explore the role of HAGLR on the malignancy of TNBC cells. Luciferase assay was used to clarify the binding between miR-335-3p with HAGLR and WNT2. The tumor formation experiment in nude mice was used to explore the function of HAGLR in vivo.

Results: HAGLR was increased in TNBC tissues and cell lines. Silencing of HAGLR inhibited viability, proliferation, migration, and invasion of BT549 cells. Furthermore, HAGLR acted as a sponge of miR-335-3p and inhibited its expression. And miR-335-3p directly targeted WNT2. Functionally, forced expression of miR-335-3p or knockdown of WNT2 removed the promoted effects of lncRNA HAGLR on TNBC development. In vivo tumorigenesis experiments indicated HAGLR accelerated tumor growth via miR-335-3p/WNT2 axis.

Conclusion: Our study revealed that HAGLR promoted the growth of TNBC, which was mediated by miR-335-3p/WNT2 axis.

Multifaceted roles of long non-coding RNAs in triple-negative breast cancer: biology and clinical applications

Triple-negative breast cancer (TNBC) is a heterogeneous breast cancer subtype that lacks targeted therapy due to the absence of estrogen, progesterone, and HER2 receptors. Moreover, TNBC was shown to have a poor prognosis, since it involves aggressive phenotypes that confer significant hindrance to therapeutic treatments. Recent state-of-the-art sequencing technologies have shed light on several long non-coding RNAs (lncRNAs), previously thought to have no biological function and were considered as genomic junk. LncRNAs are involved in various physiological as well as pathological conditions, and play a key role in drug resistance, gene expression, and epigenetic regulation. This review mainly focuses on exploring the multifunctional roles of candidate lncRNAs, and their strong association with TNBC development. We also summarise various emerging research findings that establish novel paradigms of lncRNAs function as oncogenes and/or tumor suppressors in TNBC development, suggesting their role as prospective therapeutic targets.

LINC00261 Suppresses Cisplatin Resistance of Esophageal Squamous Cell Carcinoma Through miR-545-3p/MT1M Axis

To improve the survival rate and cure rate of patients, it is necessary to find a new treatment scheme according to the molecular composition of (ESCC) in esophageal squamous cell carcinoma. Long non-coding RNAs (lncRNAs) regulate the progression of ESCC by various pathophysiological pathways. We explored the possible function of the lncRNA LINC00261 (LINC00261) on cisplatin (DDP) resistance of ESCC and its relative molecular mechanisms. In the study, we found that LINC00261 was downregulated in ESCC tissues, cell lines, and DDP-resistant ESCC patients. Besides, overexpression of LINC00261 not only inhibited cell proliferation, and DDP resistance but also promotes cell apoptosis. Further mechanistic research showed that LINC00261 sponged miR-545-3p which was negatively correlated with the expression of LINC00261. In addition, functional experiments revealed that upregulation of miR-766-5p promoted proliferation and enhanced DDP resistance. Subsequently, MT1M was testified to be the downstream target gene of miR-545-3p. Rescue experiments revealed that overexpression of MT1M largely restores miR-545-3p mimics-mediated function on ESCC progression. Our results demonstrate that the LINC00261 suppressed the DDP resistance of ESCC through miR-545-3p/MT1M axis.

Advances in Pathophysiology of Triple-Negative Breast Cancer: The Potential of lncRNAs for Clinical Diagnosis, Treatment, and Prognostic Monitoring

Recent studies have shown that long non-coding RNAs (lncRNAs) are involved in several gene expression regulation processes, including epigenetic regulation, transcriptional regulation, post-transcriptional regulation, and translation regulation. It also plays a crucial role in the regulation of several characteristics of cancer biology, and the dysregulation of lncRNA expression in cancer may be part of the cause of cancer progression. Meanwhile, more and more studies are trying to determine the association between lncRNA expression and TNBC, as well as the functional role and molecular mechanism of the abnormally expressed lncRNA. Therefore, this review lists some abnormal lncRNAs in TNBC, further analyzes their molecular mechanisms and biological roles in the development of TNBC, and summarizes the potential of lncRNAs as biomarkers and therapeutic targets of TNBC, so as to provide ideas for clinical diagnosis, targeted therapy, and prognosis monitoring of TNBC.

LncRNA HCP5 : A Potential Biomarker for Diagnosing Gastric Cancer

Background

It has been reported that long non-coding RNAs (lncRNAs) can be regarded as a biomarker and had particular clinical significance for early screening and gastric cancer (GC) diagnosis. Therefore, this study aimed to investigate whether serum HCP5 could be a new diagnostic biomarker.

Methods

Filtered out the HCP5 from the GEO database. The specificity of HCP5 was verified by real-time fluorescence quantitative PCR (qRT-PCR), and then the stability of HCP5 was verified by room temperature storage and repeated freeze-thaw experiments. Meanwhile, the accuracy of HCP5 was verified by agarose gel electrophoresis (AGE) and Sanger sequencing. Simultaneously, the expression level of serum HCP5 was detected by qRT-PCR in 98 patients with primary gastric cancer, 21 gastritis patients, 82 healthy donors, and multiple cancer types. Then, the methodology analysis was carried on. Moreover, receiver operating characteristic (ROC) was used to evaluate its diagnostic efficiency.

Results

qRT-PCR method had good repeatability and stability in detecting HCP5. The expression level of HCP5 in the serum of gastric cancer patients was remarkably higher than that of healthy controls, and it could distinguish gastritis patients from healthy donors. Besides, the expression of HCP5 was increased dramatically in MKN-45 and MGC-803. The FISH assay showed that HCP5 was mainly distributed in the cytoplasm of MKN-45 and BGC-823 cells. When HCP5 was combined with existing tumor markers, the diagnostic efficiency of HCP5 was the best, and the combined diagnosis of carcinoembryonic antigen (CEA), carbohydrate antigen199 (CA199), and HCP5 can significantly improve the diagnostic sensitivity. Besides, compared with the expression levels of thyroid cancer (THCA), colorectal cancer (CRC), and breast cancer (BRCA), serum HCP5 in gastric cancer was the most specific. Moreover, the high expression of serum HCP5 was related to differentiation, lymph node metastasis, and nerve invasion. The term of serum HCP5 after the operation was significantly lower than that of patients with primary gastric cancer.

Conclusion

Serum HCP5 can be used as a potential biomarker of non-invasive fluid biopsy, which had a unique value in the early diagnosis, development, and prognosis of gastric cancer.

Long noncoding RNAs in triple-negative breast cancer: A new frontier in the regulation of tumorigenesis

In recent years, triple-negative breast cancer (TNBC) has emerged as the most aggressive subtype of breast cancer and is usually associated with increased mortality worldwide. The severity of TNBC is primarily observed in younger women, with cases ranging from approximately 12%-24% of all breast cancer cases. The existing hormonal therapies offer limited clinical solutions in completely circumventing the TNBC, with chemoresistance and tumor recurrences being the common hurdles in the path of TNBC treatment. Accumulating evidence has correlated the dysregulation of long noncoding RNAs (lncRNAs) with increased cell proliferation, invasion, migration, tumor growth, chemoresistance, and decreased apoptosis in TNBC. Various clinical studies have revealed that aberrant expression of lncRNAs in TNBC tissues is associated with poor prognosis, lower overall survival, and disease-free survival. Due to these specific characteristics, lncRNAs have emerged as novel diagnostic and prognostic biomarkers for TNBC treatment. However, the underlying mechanism through which lncRNAs perform their actions remains unclear, and extensive research is being carried out to reveal it. Therefore, understanding of mechanisms regulating the modulation of lncRNAs will be a substantial breakthrough in effective treatment therapies for TNBC. This review highlights the association of several lncRNAs in TNBC progression and treatment, along with their possible functions and mechanisms.

HCP5 contributes to cisplatin resistance in gastric cancer through miR-128/HMGA2 axis

The long non-coding RNA HLA complex P5 (HCP5) is extensively related to cancer chemoresistance, while its function in gastric cancer (GC) has not been well elucidated yet. Here, the role and mechanism of HCP5 in regulating the chemoresistance of GC to cisplatin (DDP) was investigated. Our results revealed that HCP5 was increased in GC patients and indicated a poor prognosis. HCP5 knockdown weakens DDP resistance and reduced apoptosis of GC cells. miR-128 was decreased in GC patients and sponged by HCP5. HMGA2 was targeted by miR-128 and was increased in GC patients. HCP5 aggravated the resistance of GC cells to DDP in vitro by elevating HMGA2 expression via sponging miR-128. HCP5 silencing inhibited GC cells growth, resistance to DDP, and Ki-67 expression in vivo. In summary, HCP5 contributed to DDP resistance in GC cells through miR-128/HMGA2 axis, providing a promising therapeutic target for GC chemoresistance.

LncRNA HCP5 promotes neuroblastoma proliferation by regulating miR-186-5p/MAP3K2 signal axis

INTRODUCTION

Neuroblastoma (NB) is the most common solid tumor in children. Studies showed that long-chain noncoding RNA (lncRNA) HCP5 played an important role in tumorigenesis, but its role in NB remained unclear. This study aims to determine the role of HCP5 in NB and its possible molecular mechanism.

METHODS

We analyzed the expression levels of miRNA-186-5p and HCP5 in neuroblastoma and neuroblastoma cell lines SHSY-5Y, Kelly, NBL-S and SK-N-AS, and explored their roles.

RESULTS

We found that the HCP5 expression was up-regulated in NB tissues and cells. The higher the HCP5 expression in NB cells, the stronger the ability of clone formation. Down regulation of the HCP5 expression inhibited the proliferation of NB cells and the growth of subcutaneous transplanted tumor in nude mice. HCP5 could competitively bind miR-186-5p, while miR-186-5p could target the 3'-UTR of MAP3K2. The expression level of miR-186-5p was down regulated while the expression level of MAP3K2 was up-regulated in NB tissues. The expression level of HCP5 and miR-186-5p, the expression level of miR-186-5p and MAP3K2 were negatively correlated. The decreased proliferation of NB cells induced by down-regulation of HCP5 expression can be counteracted by miR-186-5p inhibitor or MAP3K2, and vice versa.

CONCLUSION

This study showed that lncRNA HCP5, as ceRNA, regulated MAP3K2 to promote NB progression through competitive binding of miR-186-5p. We revealed a new signaling pathway that mediates NB, which provided a new target for the diagnosis and treatment of NB.

HCP5 Promotes Proliferation and Contributes to Cisplatin Resistance in Gastric Cancer Through miR-519d/HMGA1 Axis

Introduction

The long-non-coding RNA HCP5 (HLA complex P5) has been extensively linked to the ability of cancer cells to resist chemotherapeutic interventions. Here, we investigated the role of HCP5 in gastric cancer (GC) which to-date has been poorly characterized. Our results indicated that HCP5 expression was up-regulated in GC cells.

Methods

HCP5, miR-519d, and high mobility group A1 (HMGA1) expression levels in GC cells were measured using quantitative real-time PCR (qRT-PCR) and Western blot analysis. Drug sensitivity and apoptosis of tumor cells were assessed using cell counting kit-8, flow cytometry, and caspase activity assay. Bioinformatics and luciferase reporter assays were employed for analyzing the interactions between HCP5, miR-519d, and HMGA1.

Results

HCP5 knockdown suppressed proliferation and weakened the resistance to cisplatin (DDP) of GC cells. miR-519d was down-regulated in GC cells and sponged by HCP5. HMGA1 was directly inhibited by miR-519d and its expression was up-regulated in GC cells. HCP5 exacerbated the resistance to cisplatin of GC cells in vitro by enhancing HMGA1 expression via sponging miR-519d.

Conclusion

In summary, HCP5 promoted proliferation and contributed to DDP resistance in GC cells through miR-519d/HMGA1 axis.

Down-regulation of HCP5 inhibits cell proliferation, migration, and invasion through regulating EPHA7 by competitively binding miR-101 in osteosarcoma

Patients with osteosarcoma (OS) usually have poor overall survival because of frequent metastasis. Long non-coding RNAs (lncRNAs) have been reported to be associated with tumorigenesis and metastasis. In this study, we investigated the expression and roles of lncRNA human histocompatibility leukocyte antigen (HLA) complex P5 (HCP5) in OS, aiming to provide a novel molecular mechanism for OS. HCP5 was up-regulated both in OS tissues and cell lines and high expression of HCP5 was associated to low survival in OS patients. Down-regulation of HCP5 inhibited cell proliferation, migration, and invasion, suggesting its carcinogenic role in OS. miR-101 was targeted by HCP5 and its expression was decreased in OS. The inhibitor of miR-101 reversed the impact of HCP5 down-regulation on cell proliferation, apoptosis, and metastasis in OS. Ephrin receptor 7 (EPHA7) was proved to be a target of miR-101 and had ability to recover the effects of miR-101 inhibitor in OS. In conclusion, lncRNA HCP5 knockdown suppressed cell proliferation, migration, and invasion, and induced apoptosis through depleting the expression of EPHA7 by binding to miR-101, providing a potential therapeutic strategy of HCP5 in OS.

LncRNAs and miRNAs participate in determination of sensitivity of cancer cells to cisplatin

Cisplatin is an extensively used chemotherapeutic substance for various types of human malignancies including sarcomas, carcinomas and lymphomas. Yet, the vast application of this drug is hampered by the emergence of chemoresistance in some treated patients. Several mechanisms such as degradation of the membrane transporters by cisplatin have been implicated in the pathogenesis of this event. Recent researches have also indicated the role of long non-coding RNAs (lncRNAs) as well as micoRNAs (miRNAs) in the emergence of resistance to cisplatin in several cancer types. For instance, up-regulation of miR-21 has been associated with resistance to this agent in ovarian cancer, oral squamous cell cancer, gastric malignancy and non-small cell lung cancer (NSCLC). On the other hand, down-regulation of miR-218 has been implicated in emergence of chemoresistance in breast cancer and esophageal squamous cell carcinoma. MALAT1 is implicated in the chemoresistance of bladder cancer cells, NSCLC, gastric cancer and cervical cancer. Most notably, the expression profile of resistance-associated miRNAs and lncRNAs can predict overall survival of cancer patients. Mechanistic assays have revealed that interference with expression of some miRNAs and lncRNAs can reverse the resistance phenotype in cancer cells. In this paper, we review the scientific writings on the role of lncRNAs and miRNAs in the evolution of chemoresistance to cisplatin in cancer cells.

Emerging role of non-coding RNAs in response of cancer cells to radiotherapy

Radiotherapy is an effective method for treatment of a large proportion of human cancers. Yet, the efficacy of this method is precluded by the induction of radioresistance in tumor cells and the radiation-associated injury of normal cells surrounding the field of radiation. These restrictions necessitate the introduction of modalities for either radiosensitization of cancer cells or protection of normal cells against adverse effects of radiation. Non-coding RNAs (ncRNAs) have essential roles in the determination of radiosensitivity. Moreover, ncRNAs can modulate radiation-induced side effects in normal cells. Several microRNAs (miRNAs) such as miR-620, miR-21 and miR-96-5p confer radioresistance, while other miRNAs including miR-340/ 429 confer radiosensitivity. The expression levels of a number of miRNAs are associated with radiation-induced complications such as lung fibrosis or oral mucositis. The expression patterns of several long non-coding RNAs (lncRNAs) such as MALAT1, LINC00630, HOTAIR, UCA1 and TINCR are associated with response to radiotherapy. Taken together, lncRNAs and miRNAs contribute both in modulation of response of cancer cells to radiotherapy and in protection of normal cells from the associated side effects. The current review provides an overview of the roles of these transcripts in these aspects.

Long non-coding RNA HCP5 in cancer

Cancer remains a major threat to human health worldwide. Long non-coding RNA (lncRNA) comprises a group of single-stranded RNA with lengths longer than 200 bp. LncRNAs are aberrantly expressed and play a variety of roles involving multiple cellular processes in cancer. Histocompatibility leukocyte antigen complex P5 (HCP5), initially reported in 1993, is an important lncRNA located between the MICA and MICB genes in MHC I region. HCP5 is involved many autoimmune diseases as well as malignancies. Abnormal HCP5 expression occurs in many types of cancer and its dysregulation appears closely associated with tumor progression. HCP5 is also involved in anti-tumor drug resistance as well. As such, HCP5 represents a promising biomarker and therapeutic target in cancer. In this review, we summarize recent researches and provide an overview of the role and mechanism of HCP5 in human cancer.

LncRNA HCP5 Promotes Cell Invasion and Migration by Sponging miR-29b-3p in Human Bladder Cancer

BACKGROUND

Bladder cancer (BC) is one of the most common malignant tumors in the urinary system. In this study, the roles of lncRNA HCP5 (human major histocompatibility complex p5) and miR-29b-3p in human BC were investigated. Their regulations involved in cell invasion and migration were also evaluated.

METHODS

Luciferase reporter assay was performed to detect the binding between miR-29b-3p and HCP5 or high-mobility group box 1 (HMGB1). Cell viability, migration, invasion and apoptosis were assessed by CCK-8, colony formation, transwell assay and flow cytometry, respectively. Expression levels of HMGB1/toll-like receptor 4 (TLR4) proteins were measured by Western blot. Xenograft model was built, and tumor volumes and weights were calculated.

RESULTS

The results revealed dysregulation of HCP5 and miR-29b-3p in BC samples and cells. HCP5 negatively regulated the expression of miR-29b-3p and enhanced cell viability, migration and invasion. MiR-29b-3p mediated the effect of HCP5 on cell viability, proliferation, migration and invasion in RT4 cells. In addition, miR-29b-3p could regulate the expression of HMGB1 through interaction with HMGB1.

CONCLUSION

The findings in this study supported that lncRNA HCP5 could promote cell invasion and migration by sponging miR-29b-3p in human BC.

Long Non-Coding RNAs in Drug Resistance of Breast Cancer

Breast cancer (BC) is the most common cancer and the leading cause of death in women. Advances in early diagnosis and therapeutic strategies have decreased the mortality of BC and improved the prognosis of patients to some extent. However, the development of drug resistance has limited the success rate of systemic therapies. Long non-coding RNAs (lncRNAs) are involved in drug resistance in BC via various mechanisms, which contribute to a complex regulatory network. In this review, we summarize the latest findings on the mechanisms underlying drug resistance modulated by lncRNAs in BC. In addition, we discuss the potential clinical applications of lncRNAs as targeted molecular therapy against drug resistance in BC.

The role of microRNA in cisplatin resistance or sensitivity

INTRODUCTION

Cisplatin is a chemotherapy drug that has been used to treat a number of cancers for decades, and is still one of the most commonly used anti-cancer agents. However, some patients do not respond to cisplatin while other patients who were originally sensitive to cisplatin eventually develop chemoresistance, leading to treatment failure or/and tumor recurrence.

AREAS COVERED

Different mechanisms contribute to cisplatin resistance or sensitivity, involving multiple pathways or/and processes such as DNA repair, DNA damage response, drug transport, and apoptosis. Among the various mechanisms, it appears that microRNAs play an important role in determining the resistance or sensitivity. In this article, we analyzed and summarized recent findings in this area, with the aim that these data can aid further research and understanding, leading to the eventual reduction of cisplatin resistance.

EXPERT COMMENTARY

microRNAs can positively or negatively regulate cisplatin resistance by acting on molecules or/and pathways related to apoptosis, autophagy, hypoxia, cancer stem cells, NF-κB, and Notch1. It appears that the modulation of relevant microRNAs can effectively re-sensitize cancer cells to cisplatin regimen in certain types of cancers including breast, colorectal, gastric, liver, lung, ovarian, prostate, testicular, and thyroid cancers.

Mechanistic Involvement of Long Non-Coding RNAs in Oncotherapeutics Resistance in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is one of the most lethal forms of breast cancer (BC), with a significant disease burden worldwide. Chemoresistance and lack of targeted therapeutics are major hindrances to effective treatments in the clinic and are crucial causes of a worse prognosis and high rate of relapse/recurrence in patients diagnosed with TNBC. In the last decade, long non-coding RNAs (lncRNAs) have been found to perform a pivotal role in most cellular functions. The aberrant functional expression of lncRNAs plays an ever-increasing role in the progression of diverse malignancies, including TNBC. Therefore, lncRNAs have been recently studied as predictors and modifiers of chemoresistance. Our review discusses the potential involvement of lncRNAs in drug-resistant mechanisms commonly found in TNBC and highlights various therapeutic strategies to target lncRNAs in this malignancy.

Long non-coding RNAs: Key regulators in oxaliplatin resistance of colorectal cancer

Colorectal cancer (CRC) is one of the most commonly diagnosed malignancies in the world with high relapse and mortality rates. Although oxaliplatin (OXA), a platinum-based anticancer drug, is widely used in CRC treatment, the resulting chemoresistance dramatically attenuates the drug efficacy and increases the failure rate of this therapy. Thus, the study on OXA-induced chemoresistance is extremely urgent. In recent years, emerging evidence has shown that lncRNAs play irreplaceable roles in drug resistance. However, we only have a limited knowledge of the lncRNAs that are closely related to oxaliplatin resistance in CRC. In present study, we identify and characterize these lncRNAs, including their functions, underlying mechanisms and possible applications.

Systematic characterization of non-coding RNAs in triple-negative breast cancer

Triple‐negative breast cancer (TNBC) is one of the most aggressive subtypes of breast cancer with negativity for oestrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor (HER2). Non‐coding RNAs (ncRNAs) make up most of the transcriptome and are widely present in eukaryotic cells. In recent years, emerging evidence suggests that ncRNAs, mainly microRNAs (miRNAs), long ncRNAs (lncRNAs) and circular RNAs (circRNAs), play prominent roles in the tumorigenesis and development of TNBC, but the functions of most ncRNAs have not been fully described. In this review, we systematically elucidate the general characteristics and biogenesis of miRNAs, lncRNAs and circRNAs, discuss the emerging functions of these ncRNAs in TNBC and present future perspectives in clinical practice.

DCST1-AS1 Promotes TGF-β-Induced Epithelial-Mesenchymal Transition and Enhances Chemoresistance in Triple-Negative Breast Cancer Cells via ANXA1

Triple-negative breast cancer (TNBC) is a highly metastatic breast cancer subtype, and the primary systemic treatment strategy involves conventional chemotherapy. DC-STAMP domain containing 1-antisense 1 (DCST1-AS1) is a long non-coding RNA that promotes TNBC migration and invasion. Studying the role of DCST1-AS1 in promoting epithelial–mesenchymal transition (EMT) and chemoresistance will provide a new strategy for TNBC therapy. In the present study, we found that DCST1-AS1 regulates the expression or secretion of EMT-related proteins E-cadherin, snail family zinc finger 1 (SNAI1), vimentin, matrix metallopeptidase 2 (MMP2), and matrix metallopeptidase 9 (MMP9). Interference with DCST1-AS1 impaired TGF-β-induced TNBC cell invasion and migration. DCST1-AS1 directly binds to ANXA1 in BT-549 cells and affects the expression of ANXA1. DCST1-AS1 enhances TGF-β/Smad signaling in BT-549 cells through ANXA1 to promote EMT. The combination of DCST1-AS1 and ANXA1 also contributes to enhancement of the resistance of BT-549 cells to doxorubicin and paclitaxel. In conclusion, DCST1-AS1 promotes TGF-β-induced EMT and enhances chemoresistance in TNBC cells through ANXA1, and therefore represents a potentially promising target for metastatic breast cancer therapy.

Targeted Inhibition of miR-221/222 Promotes Cell Sensitivity to Cisplatin in Triple-Negative Breast Cancer MDA-MB-231 Cells

Cisplatin has been widely used in the treatment of a various types of cancers including triple-negative breast cancer (TNBC) by damaging DNA and inducing apoptosis. However, its anti-cancer effects are often limited due to chemo-resistance, which is one of the main reasons causing cancer relapse and metastasis. To overcome resistance, cisplatin is often used in combination with other drugs or molecules. Our study found that the targeted inhibition of miR-221/222 in MDA-MB-231 cells promoted cisplatin-induced cell apoptosis, and increased the cell sensitivity to cisplatin in vitro. Much higher expression levels of miR-221/222 were detected in the cisplatin-resistant MDA-MB-231 cells and in cisplatin-resistant breast cancer patients. The combination chemotherapy of cisplatin with anti-miR-221/222 showed much higher efficiency in suppressing tumor growth in the mice transplanted with MDA-MB-231 cells. In addition, anti-miR-221 and anti-miR-222 showed synergetic effects on improving sensitivity to cisplatin in MDA-MB-231 cells. Suppression of SOCS1-STAT3-Bcl-2 pathway and activation of p53-Pten signaling both contribute to anti-miR-221/222-induced sensitivity to cisplatin in MDA-MB-231 cells. These findings suggest the potential of a novel approach for the combination chemotherapy of cisplatin with small non-coding RNA in treatment of human TNBC.

LncRNA HCP5 promotes LAML progression via PSMB8-mediated PI3K/AKT pathway activation

Acute myeloid leukemia is an aggressive myeloid malignancy, characterized by rapid cellular proliferation and generally high mortality. Due to the lack of a complete understanding of AML, its clinical outcomes are still not satisfactory. In this study, we examined the function of the long non-coding RNA-HLA complex P5 (HCP5) on AML by analyzing the clinical samples, TCGA data, and by shRNA-mediated HCP5 deficiency in vitro. Our results showed that HCP5 is highly expressed in AML and is positive associated with poor prognosis, and HCP5 knockdown was significantly suppressing AML cell line proliferation and inducing G1/S arrest in vitro. In mechanism, the proteasome subunit beta type 8 (PSMB8) expression was dramatically inhibited in HCP5 knockdown cells while increased in HCP5 overexpression cells. PSMB8 was also highly expressed in AML and with poor prognosis. Furthermore, HCP5 regulates PI3K/AKT pathway activation depending on PSMB8. Our results showed a promoting function of HCP5 on AML and may provide a compelling biomarker and therapy target for AML.

miR‑425‑5p is associated with poor prognosis in patients with breast cancer and promotes cancer cell progression by targeting PTEN

Breast cancer (BC) is the most common invasive cancer in women, and it imposes a heavy burden on patients. microRNAs (miRNAs/miRs) have been found to play an important role in the development of tumors, but their role in the malignant progression of BC is unclear. In the present study, the expression level of miR‑425‑5p was examined in patients with BC, and its association with prognosis was investigated. In vitro experiments were performed to examine role of miR‑425‑5p in the development of BC cells. A downstream target gene of miR‑425‑5p was predicted using a miRNA target prediction tool and validated with a luciferase reporter assay. It was found that miR‑425‑5p expression was increased in BC tissues and cell lines, and was associated with tumor size, clinical stage, lymph node metastasis, distant metastasis and poor overall survival in patients with BC. Knockdown of miR‑425‑5p in BC cell lines inhibited proliferation and migration. PTEN was identified as a downstream target gene of miR‑425‑5p. Overexpression of PTEN was demonstrated to partially inhibit the promotional effect of miR‑425‑5p on cell proliferation and migration. Taken together, miR‑425‑5p is associated with poor prognosis, and promotes cell proliferation and migration via PTEN. Thus, miR‑425‑5p may serve as a therapeutic and prognostic marker for BC.