Long non-coding RNA H19 regulates proliferation and doxorubicin resistance in MCF-7 cells by targeting PARP1

Critical roles of long noncoding RNA H19 in cancer

Long noncoding RNAs (lncRNAs) are a category of noncoding RNAs characterized by their length, often exceeding 200 nucleotides. There is a growing body of data that indicate the significant involvement of lncRNAs in a wide range of disorders, including cancer. lncRNA H19 was among the initial lncRNAs to be identified and is transcribed from the H19 gene. The H19 lncRNA exhibits significant upregulation in a diverse range of human malignancies, such as breast, colorectal, pancreatic, glioma, and gastric cancer. Moreover, the overexpression of H19 is frequently associated with a worse prognosis among individuals diagnosed with cancer. H19 has been shown to have a role in facilitating several cellular processes, including cell proliferation, invasion, migration, epithelial-mesenchymal transition, metastasis, and apoptosis. This article summarizes the aberrant upregulation of H19 in human malignancies, indicating promising avenues for future investigations on cancer diagnostics and therapeutic interventions.

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.

Interaction between lncRNAs and RNA-binding proteins (RBPs) influences DNA damage response in cancer chemoresistance

The DNA damage response (DDR) is a crucial cellular signaling pathway activated in response to DNA damage, including damage caused by chemotherapy. Chemoresistance, which refers to the resistance of cancer cells to the effects of chemotherapy, poses a significant challenge in cancer treatment. Understanding the relationship between DDR and chemoresistance is vital for devising strategies to overcome this resistance and improve treatment outcomes. Long non-coding RNAs (lncRNAs) are a class of RNA molecules that do not code for proteins but play important roles in various biological processes, including cancer development and chemoresistance. RNA-binding proteins (RBPs) are a group of proteins that bind to RNA molecules and regulate their functions. The interaction between lncRNAs and RBPs has been found to regulate gene expression at the post-transcriptional level, thereby influencing various cellular processes, including DDR signaling pathways. Multiple studies have demonstrated that lncRNAs can interact with RBPs to modulate the expression of genes involved in cancer chemoresistance by impacting DDR signaling pathways. Conversely, RBPs can regulate the expression and function of lncRNAs involved in DDR. Exploring these interactions can provide valuable insights for the development of innovative therapeutic approaches to overcome chemoresistance in cancer patients. This review article aims to summarize recent research on the interaction between lncRNAs and RBPs during cancer chemotherapy, with a specific focus on DDR pathways.

ncRNADrug: a database for validated and predicted ncRNAs associated with drug resistance and targeted by drugs

Drug resistance is a major barrier in cancer treatment and anticancer drug development. Growing evidence indicates that non-coding RNAs (ncRNAs), especially microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), play pivotal roles in cancer progression, therapy, and drug resistance. Furthermore, ncRNAs have been proven to be promising novel therapeutic targets for cancer treatment. Reversing dysregulated ncRNAs by drugs holds significant potential as an effective therapeutic strategy for overcoming drug resistance. Therefore, we developed ncRNADrug, an integrated and comprehensive resource that records manually curated and computationally predicted ncRNAs associated with drug resistance, ncRNAs targeted by drugs, as well as potential drug combinations for the treatment of resistant cancer. Currently, ncRNADrug collects 29 551 experimentally validated entries involving 9195 ncRNAs (2248 miRNAs, 4145 lncRNAs and 2802 circRNAs) associated with the drug resistance of 266 drugs, and 32 969 entries involving 10 480 ncRNAs (4338 miRNAs, 6087 lncRNAs and 55 circRNAs) targeted by 965 drugs. In addition, ncRNADrug also contains associations between ncRNAs and drugs predicted from ncRNA expression profiles by differential expression analysis. Altogether, ncRNADrug surpasses the existing related databases in both data volume and functionality. It will be a useful resource for drug development and cancer treatment. ncRNADrug is available at http://www.jianglab.cn/ncRNADrug.

The emerging roles of long non-coding RNA (lncRNA) H19 in gynecologic cancers

Long non-coding RNA (lncRNA) H19 has gained significant recognition as a pivotal contributor to the initiation and advancement of gynecologic cancers, encompassing ovarian, endometrial, cervical, and breast cancers. H19 exhibits a complex array of mechanisms, demonstrating dualistic effects on tumorigenesis as it can function as both an oncogene and a tumor suppressor, contingent upon the specific context and type of cancer being investigated. In ovarian cancer, H19 promotes tumor growth, metastasis, and chemoresistance through modulation of key signaling pathways and interaction with microRNAs. Conversely, in endometrial cancer, H19 acts as a tumor suppressor by inhibiting proliferation, inducing apoptosis, and regulating epithelial-mesenchymal transition. Additionally, H19 has been implicated in cervical and breast cancers, where it influences cell proliferation, invasion, and immune evasion. Moreover, H19 has potential as a diagnostic and prognostic biomarker for gynecologic cancers, with its expression levels correlating with clinical parameters and patient outcomes. Understanding the functional roles of H19 in gynecologic cancers is crucial for the development of targeted therapeutic strategies and personalized treatment approaches. Further investigation into the intricate molecular mechanisms underlying H19's involvement in gynecologic malignancies is warranted to fully unravel its therapeutic potential and clinical implications. This review aims to elucidate the functional roles of H19 in various gynecologic malignancies.

Novel Insights on Ferroptosis Modulation as Potential Strategy for Cancer Treatment: When Nature Kills

Significance: The multifactorial nature of the mechanisms implicated in cancer development still represents a major issue for the success of established antitumor therapies. The discovery of ferroptosis, a novel form of programmed cell death distinct from apoptosis, along with the identification of the molecular pathways activated during its execution, has led to the uncovering of novel molecules characterized by ferroptosis-inducing properties. Recent advances: As of today, the ferroptosis-inducing properties of compounds derived from natural sources have been investigated and interesting findings have been reported both in vitro and in vivo. Critical Issues: Despite the efforts made so far, only a limited number of synthetic compounds have been identified as ferroptosis inducers, and their utilization is still limited to basic research. In this review, we analyzed the most important biochemical pathways involved in ferroptosis execution, with particular attention to the newest literature findings on canonical and non-canonical hallmarks, together with mechanisms of action of natural compounds identified as novel ferroptosis inducers. Compounds have been classified based on their chemical structure, and modulation of ferroptosis-related biochemical pathways has been reported. Future Directions: The outcomes herein collected represent a fascinating starting point from which to take hints for future drug discovery studies aimed at identifying ferroptosis-inducing natural compounds for anticancer therapies. Antioxid. Redox Signal. 40, 40-85.

Association of altered metabolic profiles and long non-coding RNAs expression with disease severity in breast cancer patients: analysis by 1H NMR spectroscopy and RT-q-PCR

INTRODUCTION

Globally, one of the major causes of cancer related deaths in women is breast cancer. Although metabolic pattern is altered in cancer patients, robust metabolic biomarkers with a potential to improve the screening and disease monitoring are lacking. A complete metabolome profiling of breast cancer patients may lead to the identification of diagnostic/prognostic markers and potential targets.

OBJECTIVES

The aim of this study was to analyze the metabolic profile in the serum from 43 breast cancer patients and 13 healthy individuals.

MATERIALS & METHODS

We used ¹H NMR spectroscopy for the identification and quantification of metabolites. q-RT-PCR was used to examine the relative expression of lncRNAs.

RESULTS

Metabolites such as amino acids, lipids, membrane metabolites, lipoproteins, and energy metabolites were observed in the serum from both patients and healthy individuals. Using unsupervised PCA, supervised PLS-DA, supervised OPLS-DA, and random forest classification, we observed that more than 25 metabolites were altered in the breast cancer patients. Metabolites with AUC value > 0.9 were selected for further analysis that revealed significant elevation of lactate, LPR and glycerol, while the level of glucose, succinate, and isobutyrate was reduced in breast cancer patients in comparison to healthy control. The level of these metabolites (except LPR) was altered in advanced-stage breast cancer patients in comparison to early-stage breast cancer patients. The altered metabolites were also associated with over 25 signaling pathways related to metabolism. Further, lncRNAs such as H19, MEG3 and GAS5 were dysregulated in the breast tumor tissue in comparison to normal adjacent tissue.

CONCLUSION

The study provides insights into metabolic alteration in breast cancer patients. It also provides an avenue to examine the association of lncRNAs with metabolic patterns in patients.

The role of lncRNA H19 in tumorigenesis and drug resistance of human Cancers

Systemic therapy is one of the most significant cancer treatments. However, drug resistance often appears and has become the primary cause of cancer therapy failure. Regulation of drug target, drug metabolism and drug efflux, cell death escape (apoptosis, autophagy, et al.), epigenetic changes, and many other variables are complicatedly involved in the mechanisms of drug resistance. In various types of cancers, long non-coding RNA H19 (lncRNA H19) has been shown to play critical roles in tumor development, proliferation, metastasis, and multiple drug resistance as well. The efficacy of chemotherapy, endocrine therapy, and targeted therapy are all influenced by the expression of H19, especially in breast cancer, liver cancer, lung cancer and colorectal cancer. Here, we summarize the relationship between lncRNA H19 and tumorigenesis, and illustrate the drug resistance mechanisms caused by lncRNA H19 as well. This review may provide more therapeutic potential targets for future cancer treatments.

Chitosan-based nanoscale systems for doxorubicin delivery: Exploring biomedical application in cancer therapy

Green chemistry has been a growing multidisciplinary field in recent years showing great promise in biomedical applications, especially for cancer therapy. Chitosan (CS) is an abundant biopolymer derived from chitin and is present in insects and fungi. This polysaccharide has favorable characteristics, including biocompatibility, biodegradability, and ease of modification by enzymes and chemicals. CS-based nanoparticles (CS-NPs) have shown potential in the treatment of cancer and other diseases, affording targeted delivery and overcoming drug resistance. The current review emphasizes on the application of CS-NPs for the delivery of a chemotherapeutic agent, doxorubicin (DOX), in cancer therapy as they promote internalization of DOX in cancer cells and prevent the activity of P-glycoprotein (P-gp) to reverse drug resistance. These nanoarchitectures can provide co-delivery of DOX with antitumor agents such as curcumin and cisplatin to induce synergistic cancer therapy. Furthermore, co-loading of DOX with siRNA, shRNA, and miRNA can suppress tumor progression and provide chemosensitivity. Various nanostructures, including lipid-, carbon-, polymeric- and metal-based nanoparticles, are modifiable with CS for DOX delivery, while functionalization of CS-NPs with ligands such as hyaluronic acid promotes selectivity toward tumor cells and prevents DOX resistance. The CS-NPs demonstrate high encapsulation efficiency and due to protonation of amine groups of CS, pH-sensitive release of DOX can occur. Furthermore, redox- and light-responsive CS-NPs have been prepared for DOX delivery in cancer treatment. Leveraging these characteristics and in view of the biocompatibility of CS-NPs, we expect to soon see significant progress towards clinical translation.

Long non-coding RNA (lncRNA) H19 in human cancer: From proliferation and metastasis to therapy

Initiation and development of cancer depend on multiple factors that mutations in genes and epigenetic level can be considered as important drivers. Epigenetic factors include a large family of members and understanding their function in cancer has been a hot topic. LncRNAs are RNA molecules with no capacity in synthesis of proteins, and they have regulatory functions in cells. LncRNAs are localized in nucleus and cytoplasm, and their abnormal expression is related to development of tumor. This manuscript emphasizes on the role of lncRNA H19 in various cancers and its association with tumor hallmarks. The function of lncRNA H19 in most tumors is oncogenic and therefore, tumor cells increase its expression for promoting their progression. LncRNA H19 contributes to enhancing growth and cell cycle of cancers and by EMT induction, it is able to elevate metastasis rate. Silencing H19 induces apoptotic cell death and disrupts progression of tumors. LncRNA H19 triggers chemo- and radio-resistance in cancer cells. miRNAs are dually upregulated/down-regulated by lncRNA H19 in increasing tumor progression. Anti-cancer agents reduce lncRNA H19 in impairing tumor progression and increasing therapy sensitivity. A number of downstream targets and molecular pathways for lncRNA H19 have been detected in cancers including miRNAs, RUNX1, STAT3, β-catenin, Akt2 and FOXM1. Clinical studies have revealed potential of lncRNA H19 as biomarker and its association with poor prognosis. LncRNA H19 can be transferred to cancer cells via exosomes in enhancing their progression.

LncRNA H19 Impairs Chemo and Radiotherapy in Tumorigenesis

Various treatments based on drug administration and radiotherapy have been devoted to preventing, palliating, and defeating cancer, showing high efficiency against the progression of this disease. Recently, in this process, malignant cells have been found which are capable of triggering specific molecular mechanisms against current treatments, with negative consequences in the prognosis of the disease. It is therefore fundamental to understand the underlying mechanisms, including the genes—and their signaling pathway regulators—involved in the process, in order to fight tumor cells. Long non-coding RNAs, H19 in particular, have been revealed as powerful protective factors in various types of cancer. However, they have also evidenced their oncogenic role in multiple carcinomas, enhancing tumor cell proliferation, migration, and invasion. In this review, we analyze the role of lncRNA H19 impairing chemo and radiotherapy in tumorigenesis, including breast cancer, lung adenocarcinoma, glioma, and colorectal carcinoma.

Targeting the SOX2/PARP1 complex to intervene in the growth of esophageal squamous cell carcinoma

Elevated SOX2 protein levels are closely correlated with the increased incidence of esophageal squamous cell carcinoma (ESCC). However, establishing effective target measures for ESCC treatments continue to be researched. It has been previously proposed that SOX2 represents a potential therapeutic target for ESCC. Here, we found that the enzyme Poly(ADP-Ribose) polymerase 1 (PARP1) enriched in ESCCs interact with SOX2. Inhibition of PARP1 with 3-aminobenzamide (3-ABA) or shRNA knockdown reduced the proliferation of ESCCs, accompanied by decreased protein levels of SOX2. RNA sequencing demonstrated that PARP1 inhibition affected multiple signaling pathways involved in cancer cell proliferation. Additionally, 3-ABA synergistically suppressed the growth of ESCC cells when combined with cisplatin, and metformin potentiated the suppressive effect of 3-ABA on ESCC cell growth. Together these findings suggest that targeting SOX2 binding partner PARP1 provides a possible avenue to treat patients with high levels of SOX2.

Diabetes regulated anti-inflammatory lncRNA is overexpressed in triple-negative breast cancer and predicts chemoresistance and tumor recurrence

Diabetes regulated anti-inflammatory lncRNA (DRAIR) has been characterized as a critical player in type 2 diabetes mellitus. However, its role in other human diseases is unclear. Our preliminary sequencing analysis revealed an altered DRAIR level in triple-negative breast cancer (TNBC). We then explored the involvement of DRAIR in TNBC. In this study, plasma was collected from healthy controls (n = 60) and TNBC patients (n = 60). Non-tumor tissues and paired TNBC were also collected from TNBC patients. All TNBC patients received surgical resection of the primary tumors and chemotherapy. The 60 TNBC patients were divided into high and low plasma DRAIR level groups with median plasma DRAIR level as the cutoff value, and the occurrence of chemoresistance after treatment and tumor recurrence during a 5-year follow-up was monitored. Cell proliferation and viability were analyzed with BrdU assay and MTT assay, respectively. We found that plasma DRAIR levels were higher in TNBC patients than in controls. In addition, DRAIR expression in TNBC tissues was also significantly increased in TNBC tissues compared to the paired non-tumor tissues. Plasma DRAIR was positively and significantly related to DRAIR levels in TNBC tissues but not in non-tumor tissues. Patients in the high plasma DRAIR level group showed a significantly higher rate of chemoresistance after treatment and tumor recurrence during the follow-up. DRAIR promoted tumor cell proliferation and increased cell viability under doxorubicin treatment. Therefore, DRAIR is overexpressed in TNBC and predicts chemoresistance and tumor recurrence.

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.

New therapy strategies in the management of breast cancer

Breast cancer (BC), the second leading cause of cancer-related deaths after lung cancer, is the most common cancer type among women worldwide. BC comprises multiple subtypes based on molecular properties. Depending on the type of BC, hormone therapy, targeted therapy, and immunotherapy are the current systemic treatment options along with conventional chemotherapy. Several new molecular targets, miRNAs, and long non-coding RNAs (lncRNAs), have been discovered over the past few decades and are powerful potential therapeutic targets. Here, we review advanced therapeutics as new players in BC management.

Doxorubicin-loaded graphene oxide nanocomposites in cancer medicine: Stimuli-responsive carriers, co-delivery and suppressing resistance

INTRODUCTION

The application of doxorubicin (DOX) in cancer therapy has been limited due to its drug resistance and poor internalization. Graphene oxide (GO) nanostructures have the capacity for DOX delivery while promoting its cytotoxicity in cancer.

AREAS COVERED

The favorable characteristics of GO nanocomposites, preparation method, and application in cancer therapy are described. Then, DOX resistance in cancer is discussed. The GO-mediated photothermal therapy and DOX delivery for cancer suppression are described. Preparation of stimuli-responsive GO nanocomposites, surface functionalization, hybrid nanoparticles, and theranostic applications are emphasized in DOX chemotherapy.

EXPERT OPINION

Graphene oxide nanoparticle-based photothermal therapy maximizes the anti-cancer activity of DOX against cancer cells. Apart from DOX delivery, GO nanomaterials are capable of loading anti-cancer agents and genetic tools to minimize drug resistance and enhance the cytolytic impact of DOX in cancer eradication. To enhance DOX accumulation in cancer cells, stimuli-responsive (redox-, light-, enzyme- and pH-sensitive) GO nanoparticles have been developed for DOX delivery. Further development of targeted delivery of DOX-loaded GO nanomaterials against cancer cells may be achieved by surface modification of polymers such as polyethylene glycol, hyaluronic acid, and chitosan. Doxorubicin-loaded GO nanoparticles have demonstrated theranostic potential for simultaneous diagnosis and therapy. Hybridization of GO with other nanocarriers such as silica and gold nanoparticles further broadens their potential anti-cancer therapy applications.

Lectin galactoside-binding soluble 3 binding protein mediates methotrexate resistance in choriocarcinoma cell lines

Choriocarcinoma is one of the most aggressive gestational trophoblastic neoplasias (GTN). Methotrexate (MTX) resistance is the main cause of treatment failure in choriocarcinoma. However, the mechanism of MTX resistance in choriocarcinoma is poorly known. This study aims to explore the function of Lectin galactoside-binding soluble 3 binding protein (LGALS3BP) in MTX-resistance in choriocarcinoma cells. Gradual dose escalation of MTX was used to establish MTX-resistant choriocarcinoma cells (JAR-MTX and JEG3-MTX cell lines). RNA-sequencing was used to explore the differentially expressed genes. Plasmids or SiRNA transfection was used to regulate the expression of LGALS3BP. ELISA was used to detect the concentrations of LGALS3BP in the serum of MTX-sensitive and MTX-resistant patients. qRT-PCR, Western blot, and CCK-8 assay were used to determine the effects of LGALS3BP on MTX-resistance in JAR and JEG3 cells. The results showed the relative resistance index (RI) of MTX is 791.50 and 1040.04 in JAR-MTX and JEG3-MTX, respectively. LGALS3BP was up-regulated in MTX-resistant cells compared to original cells in both RNA and protein level. The concentrations of LGALS3BP were higher in the sera of MTX-resistant patients than in MTX-sensitive patients. Knocking down LGALS3BP can reverse the MTX-resistance in JAR-MTX and JEG3-MTX cells. In summary, we preliminarily established two MTX-resistant cells, and performed RNA-sequencing, and found LGALS3BP may play important role in MTX-resistance. Our work not only provides a research tool (MTX-resistant cells) for other researchers, but gives some hint on how MTX resistance is regulated.

Long intergenic non-protein coding RNA 1273 confers sorafenib resistance in hepatocellular carcinoma via regulation of methyltransferase 3

Hepatocellular carcinoma (HCC) is often diagnosed in patients with advanced disease who are ineligible for curative surgical therapies. Sorafenib is a first-line agent approved for the treatment of advanced HCC. However, the frequent resistance of HCC cells to sorafenib greatly reduces its efficacy. Herein, we describe a novel long non-coding RNA (lncRNA) conferring sorafenib resistance. Long intergenic non-protein coding RNA 1273 (LINC01273) was significantly overexpressed in human HCC and sorafenib-resistant tissues, linking it to poor overall and relapse-free survival. We established sorafenib-resistant Huh7 (Huh7-SR) and SMMC-7721 (SMMC-7721-SR) cells, and found that the knockdown of LINC01273 repressed the viability, colony formation, and DNA synthesis rate of Huh7-SR and SMMC-7721-SR cells. The level of N6-methyladenosine (m⁶A) in sorafenib-resistant HCC cells was significantly decreased, which was rescued by LINC01273 silencing. Mechanistically, LINC01273 complementarity bound to miR-600, served as a ‘reservoir’ increasing miR-600 stability, and facilitating miR-600 targeting methyltransferase 3 (METTL3), a m⁶A ‘writer’, resulting in reducing METTL3 level. In addition, LINC01273 was modified with m⁶A, METTL3 increased LINC01273 m⁶A modification, followed by LINC01273 decay in the presence of YTHDF2, a m⁶A ‘reader’. Our findings reveal the key role of LINC01273 in sorafenib-resistant HCC cells, and targeting of the newly identified LINC01273/miR-600/METTL3 feedback regulatory axis may be a promising effective intervention for HCC patients with sorafenib resistance.

Long non-coding RNA nuclear-enriched abundant transcript 1 (LncRNA NEAT1) upregulates Cyclin T2 (CCNT2) in laryngeal papilloma through sponging miR-577/miR-1224-5p and blocking cell apoptosis

Long non-coding RNA nuclear-enriched abundant transcript 1 (Lnc-NEAT1) is a crucial mediator in cancer progression, which is associated with poor prognosis of patients with laryngeal papilloma (LP). Herein, we aimed to determine how Lnc-NEAT1 promotes LP development. q-PCR, MTT, EDU and Western blotting were performed to determine that Lnc-NEAT1 facilitates LP cell proliferation and hinders cell apoptosis. LncBase database, q-PCR, GEPIA online database, Dual luciferase reporter and RIP assays were utilized to confirm that Lnc-NEAT1 sponged miR-577/miR-1224-5p and negatively mediated CCNT2. Western blotting, MTT and EDU were used to confirm that Lnc-NEAT1 promoted LP cell proliferation and inhibited cell apoptosis through CCNT2. Lnc-NEAT1 was highly expressed in LP, and enhanced LP cell proliferation, and it was inhibited by Lnc-NEAT1 depleting. Concerning the underlying mechanism, it was found that Lnc-NEAT1 could functionally sponge microRNA-577 (miR-577) and microRNA-1224-5p (miR-1224-5p) and up-regulate Cyclin T2 (CCNT2) in LP cells. Notably, CCNT2 knockdown blocked Lnc-NEAT1-induced LP cell proliferation, and rescued cell apoptosis, which was specifically indicated by restoration of Bax, Cleaved caspase 3 and Cleaved caspase 9. Lnc-NEAT1 played a carcinogenic role in LP through mediating miR-577 or miR-1224-5p/CCNT2 axis, which may provide promising insights for the treatment of LP.

Sitagliptin protects renal glomerular endothelial cells against high glucose-induced dysfunction and injury

Sitagliptin is a well-established anti-diabetic drug that also exerts protective effects on diabetic complications. Previous work reveals that sitagliptin has a protective effect on diabetic nephropathy (DN). Vascular impairment frequently occurs in diabetic renal complications. Here, we evaluated the protective function of sitagliptin in human renal glomerular endothelial cells (HrGECs) under high glucose (HG) conditions. Expressions of the pro-inflammatory cytokines interleukin-1β (IL-1β) and interleukin-8 (IL-8) were assessed using real-time PCR and ELISA. Endothelial cells permeability was assayed using the fluorescein isothiocyanate dextran (FITC-dextran) and trans-endothelial electrical resistance (TEER) assay. The results show that sitagliptin mitigated HG-induced oxidative stress in HrGECs with decreased levels of mitochondrial reactive oxygen species (ROS), Malondialdehyde (MDA), and 8-hydroxydeoxyguanosine (8-OHdG). Sitagliptin inhibited HG-induced production of pro-inflammatory cytokines interleukin-1β (IL-1β) and interleukin-8 (IL-8) in HrGECs. It also ameliorated HG-induced aggravation of HrGECs permeability and reduction of the tight junction component claudin-5. Moreover, kruppel Like Factor 6 (KLF6) mediated the protective effects of sitagliptin on endothelial monolayer permeability against HG. Collectively, sitagliptin reversed the HG-induced oxidative stress, inflammation, and increased permeability in HrGECs via regulating KLF6. This study suggests that sitagliptin might be implicated as an effective strategy for preventing diabetic renal injuries in the future.

Close interactions between lncRNAs, lipid metabolism and ferroptosis in cancer

Abnormal lipid metabolism including synthesis, uptake, modification, degradation and transport has been considered a hallmark of malignant tumors and contributes to the supply of substances and energy for rapid cell growth. Meanwhile, abnormal lipid metabolism is also associated with lipid peroxidation, which plays an important role in a newly discovered type of regulated cell death termed ferroptosis. Long noncoding RNAs (lncRNAs) have been proven to be associated with the occurrence and progression of cancer. Growing evidence indicates that lncRNAs are key regulators of abnormal lipid metabolism and ferroptosis in cancer. In this review, we mainly summarized the mechanism by which lncRNAs regulate aberrant lipid metabolism in cancer, illustrated that lipid metabolism can also influence the expression of lncRNAs, and discussed the mechanism by which lncRNAs affect ferroptosis. A comprehensive understanding of the interactions between lncRNAs, lipid metabolism and ferroptosis could help us to develop novel strategies for precise cancer treatment in the future.

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

Simple Summary

Breast cancer is the most common cancer in women, representing about one third of cancers in developed countries. Despite recent advances in diagnostic methods and increasingly early detection, breast cancer recurrence occurs in more than 20% of patients. Chemoresistance represents an important cause of this recurrence, but the mechanisms involved in this phenomenon, are still largely unknown. One feature of chemoresistant cancer cells is the reorientation of the energetic metabolism to sustain cell proliferation. Recently, long non-coding RNAs (lncRNAs) have emerged as important regulators of cellular metabolic orientation. In the present work, we gave special attention to the long non-coding RNA SAMMSON and addressed the role of this lncRNA in metabolic orientation and chemoresistance of doxorubicin-resistant breast cancer cells. The results shed light on the possible modulation of the SAMMSON expression as an innovative therapeutic approach to target chemoresistant cancer cells specifically.

Abstract

Despite improvements in therapeutic strategies for treating breast cancers, tumor relapse and chemoresistance remain major issues in patient outcomes. Indeed, cancer cells display a metabolic plasticity allowing a quick adaptation to the tumoral microenvironment and to cellular stresses induced by chemotherapy. Recently, long non-coding RNA molecules (lncRNAs) have emerged as important regulators of cellular metabolic orientation. In the present study, we addressed the role of the long non-coding RNA molecule (lncRNA) SAMMSON on the metabolic reprogramming and chemoresistance of MCF-7 breast cancer cells resistant to doxorubicin (MCF-7dox). Our results showed an overexpression of SAMMSON in MCF-7dox compared to doxorubicin-sensitive cells (MCF-7). Silencing of SAMMSON expression by siRNA in MCF-7dox cells resulted in a metabolic rewiring with improvement of oxidative metabolism, decreased mitochondrial ROS production, increased mitochondrial replication, transcription and translation and an attenuation of chemoresistance. These results highlight the role of SAMMSON in the metabolic adaptations leading to the development of chemoresistance in breast cancer cells. Thus, targeting SAMMSON expression levels represents a promising therapeutic route to circumvent doxorubicin resistance in breast cancers.

Long non-coding RNA (LncRNA) CASC9/microRNA(miR)-590-3p/sine oculis homeobox 1 (SIX1)/NF-κB axis promotes proliferation and migration in breast cancer

Long non-coding RNA (lncRNA)–microRNA–mRNA signaling axes have recently been shown to have a key role in the development of breast cancer (BC). In this study, we investigated how the cancer susceptibility candidate 9 (CASC9) gene affects the cell growth, invasion, migration, and apoptosis of BC cells. The levels of microRNA-590-3p (miR-590-3p), CASC9, and the sine oculis homeobox 1 (SIX1) gene were determined through qRT-PCR. We conducted cell counting kit-8 (CCK-8) assays to assess cell proliferation, transwell assays to detect cell migration/invasion, and flow cytometry to evaluate cell apoptosis. StarBase v2.0 was used to predict interactions between miR-590-3p and SIX1 or CASC9, and dual-luciferase reporter assays were used to verify these predictions. CASC9 protein was overexpressed in BC cells and tissues, while CASC9 knockdown inhibited BC cell growth, invasion, and migration and promoted apoptosis. Additionally, we verified that CASC9 competes for binding with miR-590-3p. Moreover, SIX1 was determined to be a target of miR-590–3p, and SIX1 expression was inhibited by miR-590-3p overexpression. CASC9 enhanced BC development by downregulating miR-590-3p and upregulating SIX1 during the activation of the NF-κB pathway. These data suggest that the CASC9/miR-590-3p/SIX1/NF-κB axis is involved in breast cancer progression, providing insight into the function of CASC9 in breast cancer development.

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.

Long non-coding RNA FOXD3 antisense RNA 1 augments anti-estrogen resistance in breast cancer cells through the microRNA-363/ trefoil factor 1/ phosphatidylinositol 3-kinase/protein kinase B axis

Long non-coding RNA (lncRNA) FOXD3 antisense RNA 1 (FOXD3-AS1) has been reported to participate in multiple processes that contribute toward the development of cancer. The present study aimed to explore the effect of lncRNA FOXD3-AS1 on anti-estrogen resistance in breast cancer (BC) cells. FOXD3-AS1 was found to be highly expressed in BC cell lines. Moreover, FOXD3-AS1 was highly expressed in estrogen receptor-negative (ER^-) cells compared to the ER-positive (ER⁺) cells. FOXD3-AS1 overexpression in T47D and MCF-7 (ER⁺) cells enhanced the resistance of cells to tamoxifen (TMX), whereas FOX3-AS1 downregulation reduced the TMX resistance in MDA-MB-231 (ER^-) cells. Similar results were reproduced in vivo that FOXD3-AS1 inhibition reduced the growth of xenograft tumors formed by MDA-MB-231 cells following TMX treatment whereas FOXD3-AS1 overexpression in T47D cells facilitated tumor growth. The bioinformatic analysis and luciferase assays indicated that FOXD3-AS1 sponged microRNA-363 (miR-363) to restore expression of trefoil factor 1 (TFF1) mRNA. Overexpression of miR-363 reduced T47D cell proliferation induced by FOXD3-AS1, whereas overexpression of TFF1 restored growth of MDA-MB-231 cells reduced after FOXD3-AS1 silencing. The phosphorylation of phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) was increased by FOXD3-AS1 but attenuated by miR-363. Inhibition of PI3K/Akt blocked the role of FOXD3-AS1 and reduced the TMX resistance in T47D and MCF-7 cells. Taken together, the present study suggested that FOXD3-AS1 sponges miR-363 to upregulate TFF1 expression, leading to PI3K/Akt signaling activation and anti-estrogen resistance in BC cells.

Long non-coding RNAs as the critical regulators of doxorubicin resistance in tumor cells

Resistance against conventional chemotherapeutic agents is one of the main reasons for tumor relapse and poor clinical outcomes in cancer patients. Various mechanisms are associated with drug resistance, including drug efflux, cell cycle, DNA repair and apoptosis. Doxorubicin (DOX) is a widely used first-line anti-cancer drug that functions as a DNA topoisomerase II inhibitor. However, DOX resistance has emerged as a large hurdle in efficient tumor therapy. Furthermore, despite its wide clinical application, DOX is a double-edged sword: it can damage normal tissues and affect the quality of patients’ lives during and after treatment. It is essential to clarify the molecular basis of DOX resistance to support the development of novel therapeutic modalities with fewer and/or lower-impact side effects in cancer patients. Long non-coding RNAs (lncRNAs) have critical roles in the drug resistance of various tumors. In this review, we summarize the state of knowledge on all the lncRNAs associated with DOX resistance. The majority are involved in promoting DOX resistance. This review paves the way to introducing an lncRNA panel marker for the prediction of the DOX response and clinical outcomes for cancer patients.

Oncogenic role of early growth response-1 in liver cancer through the regulation of the microRNA-675/sestrin 3 and the Wnt/β-catenin signaling pathway

Early growth response-1 (EGR1) is a multi-domain protein and an immediate early transcription factor that is induced during liver injury and controls the expression of a variety of genes implicated in metabolism, cell proliferation, and tumorigenesis. Liver cancer (LC) is a highly malignant disease with high mortality worldwide. This study focused on the function of EGR1 in LC development and the mechanism of action. Two LC-related datasets GSE101728 and GSE138178 downloaded from the Gene Expression Omnibus (GEO) database were used for identification of key genes involved in cancer progression. A microarray analysis was conducted to identify differentially expressed microRNAs (miRNAs) after EGR1 knockdown. The target gene of miR-675 was identified by integrated analysis. EGR1 and miR-675 were highly expressed, whereas sestrin 3 (SESN3) was poorly expressed in LC tissues and cells. High EGR1 expression was associated with poor liver function and disease severity in patients with LC. Knockdown of EGR1 weakened proliferation and invasiveness of LC cells. EGR1 bound to the miR-675 promoter and increased its transcription, and miR-675 bound to SESN3 mRNA to induce its downregulation. miR-675 upregulation promoted the malignance of LC cells, but further upregulation of SESN3 reduced invasiveness of cells. SESN3 was enriched in the Wnt/β-catenin signaling. EGR1 and miR-675 activated the Wnt/β-catenin through downregulating SESN3. This study demonstrated that EGR1 promotes the malignant behaviors of LC cells through mediating the miRNA-675/SESN3/Wnt/β-catenin axis.

Long Non-Coding RNA LINC00152 Regulates Self-Renewal of Leukemia Stem Cells and Induces Chemo-Resistance in Acute Myeloid Leukemia

Relapse of acute myeloid leukemia (AML) has a very poor prognosis and remains a common cause of treatment failure in patients with this disease. AML relapse is partially driven by the chemoresistant nature of leukemia stem cells (LSCs), which remains poorly understood, and our study aimed at elucidating the underlying mechanism. Accumulating evidences show that long noncoding RNAs (lncRNAs) play a crucial role in AML development. Herein, the lncRNA, LINC00152, was identified to be highly expressed in CD34+ LSCs and found to regulate the self-renewal of LSCs derived from AML patients. Importantly, LINC00152 upregulation was correlated with the expression of 16 genes within a 17-gene LSC biomarker panel, which contributed to the accurate prediction of initial therapy resistance in AML. Knockdown of LINC00152 markedly increased the drug sensitivity of leukemia cells. Furthermore, LINC00152 expression was found to be correlated with poly (ADP-ribose) polymerase 1 (PARP1) expression in AML, whereas LINC00152 knockdown significantly decreased the expression of PARP1. Upregulation of LINC00152 or PARP1 was associated with poor prognosis in AML patients. Collectively, these data highlight the importance and contribution of LINC00152 in the regulation of self-renewal and chemoresistance of LSCs in AML.

The role of miRNAs and lncRNAs in conferring resistance to doxorubicin

Doxorubicin is a chemotherapeutic agent that inhibits topoisomerase II, intercalates within DNA base pairs and results in oxidative DNA damage, thus inducing cell apoptosis. Although it is effective in the treatment of a wide range of human cancers, the emergence of resistance to this drug can increase tumour growth and impact patients' survival. Numerous molecular mechanisms and signalling pathways have been identified that induce resistance to doxorubicin via stimulation of cell proliferation, cell cycle switch and preclusion of apoptosis. A number of microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) have also been identified that alter sensitivity to doxorubicin. Understanding the particular impact of these non-coding RNAs in conferring resistance to doxorubicin has considerable potential to improve selection of chemotherapeutic regimens for cancer patients. Moreover, modulation of expression of these transcripts is a putative strategy for combating resistance. In the current paper, the influence of miRNAs and lncRNAs in the modification of resistance to doxorubicin is discussed.

LncRNA LHFPL3-AS1 Promotes Oral Squamous Cell Carcinoma Growth and Cisplatin Resistance Through Targeting miR-362-5p/CHSY1 Pathway

Background

Oral squamous cell carcinoma (OSCC) is a common oral cancer. The current study aims to elucidate the potential roles of long noncoding RNA (lncRNA) LHFPL3-AS1 in OSCC development.

Methods

Gene expression was measured by qRT-PCR in tumor tissues and cell lines. Loss-of-function assays were performed to analyze the effects of LHFPL3-AS1 on malignant behaviors. Bioinformatics analysis was conducted to explore the downstream signaling pathway of LHFPL3-AS1 in OSCC.

Results

LHFPL3-AS1 was highly expressed in OSCC tissues and cell lines. LHFPL3-AS1 was upregulated in cisplatin-resistant tumor cell lines. LHFPL3-AS1 level was correlated with survival rate. LHFPL3-AS1 knockdown suppressed OSCC proliferation, migration and invasion. LHFPL3-AS1 downregulation reduced cisplatin resistance of OSCC cells. LHFPL3-AS1 was the competing endogenous RNA (ceRNA) for miR-194-5p to enhance CHSY1 expression.

Conclusion

LHFPL3-AS1/miR-362-5p/CHSY1 signaling pathway plays essential roles in regulating OSCC development and cisplatin resistance.

The role of H19 lncRNA in conferring chemoresistance in cancer cells

H19 is an oncofetal transcript with crucial roles in the development and progression of several neoplastic cells. With anti-apoptotic, pro-proliferative, and pro-migratory functions, H19 affects the carcinogenic process from different functional points. In addition, H19 has central roles in the induction of chemoresistance in breast cancer, lung cancer, glioma, liver cancer, and other types of cancers. Induction of EMT, activation of oncogenic signaling pathways, and changes in the tumor microenvironment are among mechanisms of participation of H19 in chemoresistance. Paclitaxel, doxorubicin, tamoxifen, erlotinib, gefitinib, temozolomide, and methotrexate are among therapeutic agents whose efficacy is influenced by the expression of H19. In the present paper, we discuss the impact of H19 in conferring resistance to chemotherapeutic agents in different cancers.

The double-edged sword of H19 lncRNA: Insights into cancer therapy

H19 long non-coding RNA (lncRNA) has many functions in cancer. Some studies have reported that H19 acts as an oncogene and is involved in cancer progression by activating epithelial-mesenchymal transition (EMT), the cell cycle and angiogenesis via mechanisms like microRNA (miRNA) sponging - the binding to and inhibition of miRNA activity. This makes H19 lncRNA a potential target for cancer therapeutics. However, several conflicting studies have also found that H19 suppresses tumour development. In this review, we shed light on the possible reasons for these conflicting findings. We also summarise the current literature on the applications of H19 lncRNA in cancer therapy in many cancers and explore new avenues for future research. This includes the use of H19 in recombinant vectors, chemoresistance, epigenetic regulation, tumour microenvironment alteration and cancer immunotherapy. The relationship between H19 and the master tumour suppressor gene p53 is also explored. In most studies, H19 knockdown via RNA interference (RNAi) or epigenetic silencing inhibits cancer development. Thus, H19 lncRNA could be a promising target for the development of cancer therapeutics. This warrants further investigations into its translational research to improve cancer therapy outcomes.

Managing therapeutic resistance in breast cancer: from the lncRNAs perspective

Breast cancer (BC) is the most common female malignancy and the second leading cause of cancer-related death worldwide. In spite of significant advances in clinical management, the mortality of BC continues to increase due to the frequent occurrence of treatment resistance. Intensive studies have been conducted to elucidate the molecular mechanisms underlying BC therapeutic resistance, including increased drug efflux, altered drug targets, activated bypass signaling pathways, maintenance of cancer stemness, and deregulated immune response. Emerging evidence suggests that long noncoding RNAs (lncRNAs) are intimately involved in BC therapy resistance through multiple modes of action. Therefore, an in-depth understanding of the implication of lncRNAs in resistance to clinical therapies may improve the clinical outcome of BC patients. Here, we highlight the role and underlying mechanisms of lncRNAs in regulating BC treatment resistance with an emphasis on lncRNAs-mediated resistance in different clinical scenarios, and discuss the potential of lncRNAs as novel biomarkers or therapeutic targets to improve BC therapy response.

Curcumin in cancer therapy: A novel adjunct for combination chemotherapy with paclitaxel and alleviation of its adverse effects

Dealing with cancer is of importance due to enhanced incidence rate of this life-threatening disorder. Chemotherapy is an ideal candidate in overcoming and eradication of cancer. To date, various chemotherapeutic agents have been applied in cancer therapy and paclitaxel (PTX) is one of them. PTX is a key member of taxane family with potential anti-tumor activity against different cancers. Notably, PTX has demonstrated excellent proficiency in elimination of cancer in clinical trials. This chemotherapeutic agent is isolated from Taxus brevifolia, and is a tricyclic diterpenoid. However, resistance of cancer cells into PTX chemotherapy has endangered its efficacy. Besides, administration of PTX is associated with a number of side effects such as neurotoxicity, hepatotoxicity, cardiotoxicity and so on, demanding novel strategies in obviating PTX issues. Curcumin is a pharmacological compound with diverse therapeutic effects including anti-tumor, anti-oxidant, anti-inflammatory, anti-diabetic and so on. In the current review, we demonstrate that curcumin, a naturally occurring nutraceutical compound is able to enhance anti-tumor activity of PTX against different cancers. Besides, curcumin administration reduces adverse effects of PTX due to its excellent pharmacological activities. These topics are discussed with an emphasis on molecular pathways to provide direction for further studies in revealing other signaling networks.