The Essential Role of H19 Contributing to Cisplatin Resistance by Regulating Glutathione Metabolism in High-Grade Serous Ovarian Cancer

Targeting ncRNAs to overcome metabolic reprogramming‑mediated drug resistance in cancer (Review)

The emergence of resistance to antitumor drugs in cancer cells presents a notable obstacle in cancer therapy. Metabolic reprogramming is characterized by enhanced glycolysis, disrupted lipid metabolism, glutamine dependence and mitochondrial dysfunction. In addition to promoting tumor growth and metastasis, metabolic reprogramming mediates drug resistance through diverse molecular mechanisms, offering novel opportunities for therapeutic intervention. Non‑coding RNAs (ncRNAs), a diverse class of RNA molecules that lack protein‑coding function, represent a notable fraction of the human genome. Due to their distinct expression profiles and multifaceted roles in various cancers, ncRNAs have relevance in cancer pathophysiology. ncRNAs orchestrate metabolic abnormalities associated with drug resistance in cancer cells. The present review provides a comprehensive analysis of the mechanisms by which metabolic reprogramming drives drug resistance, with an emphasis on the regulatory roles of ncRNAs in glycolysis, lipid metabolism, mitochondrial dysfunction and glutamine metabolism. Furthermore, the present review aimed to discuss the potential of ncRNAs as biomarkers for predicting chemotherapy responses, as well as emerging strategies to target ncRNAs that modulate metabolism, particularly in the context of combination therapy with anti‑cancer drugs.

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

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

Long Non-Coding RNAs in Ovarian Cancer: Mechanistic Insights and Clinical Applications

Background/Objectives: Ovarian cancer is a leading cause of gynecological cancer mortality worldwide, often diagnosed at advanced stages due to vague symptoms and the lack of effective early detection methods. Long non-coding RNAs (lncRNAs) have emerged as key regulators in cancer biology, influencing cellular processes such as proliferation, apoptosis, and chemoresistance. This review explores the multifaceted roles of lncRNAs in ovarian cancer pathogenesis and their potential as biomarkers and therapeutic targets. Methods: A comprehensive literature review was conducted to analyze the structural and functional characteristics of lncRNAs and their contributions to ovarian cancer biology. This includes their regulatory mechanisms, interactions with signaling pathways, and implications for therapeutic resistance. Advanced bioinformatics and omics approaches were also evaluated for their potential in lncRNA research. Results: The review highlights the dual role of lncRNAs as oncogenes and tumor suppressors, modulating processes such as cell proliferation, invasion, and angiogenesis. Specific lncRNAs, such as HOTAIR and GAS5, demonstrate significant potential as diagnostic biomarkers and therapeutic targets. Emerging technologies, such as single-cell sequencing, provide valuable insights into the tumor microenvironment and the heterogeneity of lncRNA expression. Conclusions: LncRNAs hold transformative potential in advancing ovarian cancer diagnosis, prognosis, and treatment. Targeting lncRNAs or their associated pathways offers promising strategies to overcome therapy resistance and enhance personalized medicine. Continued research integrating omics and bioinformatics will be essential to unlock the full clinical potential of lncRNAs in ovarian cancer management.

Serum lncRNAs TUG1, H19, and NEAT1 and their target miR-29b/SLC3A1 axis as possible biomarkers of preeclampsia: Potential clinical insights

To date, the epigenetic signature of preeclampsia (PE) is not completely deciphered. Oxidative stress-responsive long non-coding RNAs (lncRNAs) are deregulated in preeclamptic placenta; however, their circulating profiles and diagnostic abilities are still unexplored. We investigated serum redox-sensitive lncRNAs TUG1, H19, and NEAT1, and their target miR-29b/cystine/neutral/dibasic amino acids transporter solute carrier family 3, member 1 (SLC3A1) as potential non-invasive biomarkers of PE risk, onset, and severity. We recruited 82 patients with PE and 78 healthy pregnant women. We classified PE patients into early-onset (EOPE) and late-onset (LOPE) subgroups at a cut-off 34 gestational weeks and into severe and mild PE subgroups by blood pressure and proteinuria criteria. Bioinformatics analysis was employed to select lncRNAs/microRNA/target gene interactions. Serum H19, NEAT1, and SLC3A1 mRNA expression were reduced, meanwhile miR-29b levels were elevated, whereas there was no significant difference in TUG1 levels between PE patients and healthy pregnancies. Serum H19 levels were lower, whereas miR-29b levels were higher in EOPE versus LOPE. Serum miR-29b and H19 levels were higher in severe versus mild PE. ROC analysis identified serum H19, NEAT1, miR-29b, and SLC3A1 as potential diagnostic markers, with H19 (AUC = 0.818, 95%CI = 0.744-0.894) and miR-29b (AUC = 0.82, 95%CI = 0.755-0.885) were superior discriminators. Only H19 and miR-29b discriminated EOPE and severe PE cases. In multivariate logistic analysis, miR-29b and H19 were associated with EOPE, using maternal age and gestational age as covariates, while miR-29b was associated with severe PE, using maternal age as covariate. Studied markers were correlated with clinical and ultrasound data in the overall PE group. Serum H19 and TUG1 were negatively correlated with albuminuria in EOPE and LOPE, respectively. NEAT1 and SLC3A1 were correlated with ultrasound data in EOPE. Likewise, TUG1, miR-29b, and SLC3A1 showed significant correlations with ultrasound data in LOPE. Conclusively, this study configures SLC3A1 expression as a novel potential serum biomarker of PE and advocates serum H19 and miR-29b as biomarkers of EOPE and miR-29b as a biomarker of PE severity.

The Role of Long Non-Coding RNAs in Ovarian Cancer Cells

Among the most deadly malignancies that strike women worldwide, ovarian cancer is still one of the most common. The primary factor affecting a patient's survival is early lesion discovery. Unfortunately, because ovarian cancer is a sneaky illness that usually manifests as nonspecific symptoms only in advanced stages, its early detection and screening are challenging. A lot of research is being conducted on effective methods of diagnosing and treating ovarian cancer. Recently, non-coding RNAs (ncRNAs) have gained great popularity, which are considered to be the main regulators of many cellular processes, especially those occurring in cancer. LncRNAs are also being studied for their therapeutic use in the treatment of ovarian cancer and their use in diagnostics and as indicators of poor prognosis. In this article, we reviewed lncRNAs described in the literature that may play an important role in ovarian cancer.

LUCAT1 Activates the Malignant Phenotypes of Lung Cancer Cells via Regulating P53 Ubiquitination

Background

Long non-coding RN (lncRNAs) have been implicated in lung cancer, but the mechanisms stay unclear. We investigated the theatrical role and mechanism of lncRNA Lung cancer associated transcript 1 LUCAT1 in the malignant progress of lung cancer.

Methods

From May 2022 to March 2023, a total of thirty normal and cancerous tissues were collected from patients diagnosed with non-small cell lung cancer at Zhongke Gengjiu Hospital in Anhui Province, China. The human SPC-A1 and A549 cell lines were chosen as the subjects for the relevant cellular experiments in this study. LncRNAs were expressed in a different manner identified by bioinformatics methods, and the expression levels in lung cancer tissues as well as cells were verified by the qRT-PCR assay. The biological role of LUCAT1 in NSCLC was determined by CCK-8, EdU, and transwell assay.

Results

The regulation of ubiquitin of P53 by LUCAT1 was studied, which showed that LUCAT1 was significantly elevated in NSCLC cell lines and patients' tissues (P<0.05). High levels of LUCAT1 promoted the proliferation, invasion, and migration of NSCLC cells. Mechanism studies showed that LUCAT1 was mainly located in the nucleus, which bound to P53 and mediated the ubiquitinated degradation of P53. Meanwhile, LUCAT1 knockdown attenuated the ubiquitination process of P53. In addition, rescue experiments illustrated that LUCAT1 induced the proliferation and invasion of NSCLC cells, and played a key role in the survival and tumorigenicity of NSCLC cells by mediating the ubiquitination of P53.

Conclusion

Collectively, LUCAT1 activated the malignant phenotypes of NSCLC cells via regulating P53 ubiquitination, which provided a new idea for the diagnosis and treatment of NSCLC.

Nuclear factor erythroid 2-related factor 2 promotes radioresistance by regulating glutamate-cysteine ligase modifier subunit and its unique immunoinvasive pattern

The enzyme glutamate-cysteine ligase modifier subunit (GCLM) serves as the initial rate-limiting factor in glutathione (GSH) synthesis. GSH is the preferred substrate for glutathione peroxidase 4 (GPX4), directly impacting its activity and stability. This study aims to elucidate the expression of GCLM and its correlation with the nuclear factor erythroid 2-related factor 2 (NFE2L2), commonly referred to as NRF2, in esophageal squamous cell carcinoma (ESCC) and further investigate the potential signaling axis of radiotherapy resistance caused by NRF2-mediated regulation of ferroptosis in ESCC. The expression of NRF2, GCLM, and GPX4 in ESCC was analyzed by bioinformatics, and their relationship with ferroptosis was verified through cell function experiments. Their role in radioresistance was then investigated through multiple validation steps. Bioinformatics analysis was employed to determine the immune infiltration pattern of NRF2 in ESCC. Furthermore, the effect of NRF2-mediated massive macrophage M2 infiltration on radiotherapy and ferroptosis was validated through in vivo experiments. In vitro assays demonstrated that overactivated NRF2 promotes radioresistance by directly binding to the promoter region of GCLM. The Tumor Immune Estimation Resource (TIMER) and quanTIseq analyses revealed NRF2 enrichment in M2 macrophages with a positive correlation. Co-culturing KYSE450 cells with M2 macrophages demonstrated that a significant infiltration of macrophages M2 can render ESCC cells resistant to radiotherapy but restore their sensitivity to ferroptosis in the process. Our study elucidates a link between the NRF2-GCLM-GSH-GPX4 signaling axis in ESCC, highlighting its potential as a therapeutic target for antagonistic biomarkers of resistance in the future. Additionally, it provides a novel treatment avenue for ESCC metastasis and radioresistance.

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.

Intratumoral microbiome is associated with gastric cancer prognosis and therapy efficacy

The role of the intratumoral microbiome in gastric cancer (GC) has not been comprehensively assessed. Here, we explored the relationship between the microbial community and GC prognosis and therapy efficacy. Several cancer-associated microbial characteristics were identified, including increased α-diversity, differential β-diversity, and decreased Helicobacter pylori abundance. After adjusting for clinical features, prognostic analysis revealed 2 phyla, 14 genera, and 5 species associated with the overall survival of patients with GC. Additionally, 2 phyla, 14 genera, and 6 species were associated with adjuvant chemotherapy (ACT) efficacy in patients with stage II - III GC. Furthermore, we classified GC microbiome structures into three microbial subtypes (MS1, MS2 and MS3) with distinguishing features. The MS1 subtype exhibited high immune activity and enrichment of microbiota related to immunotherapy and butyric acid-producing, as well as potential benefits in immunotherapy. MS2 featured the highest α-diversity and activation of the TFF pathway, MS3 was characterized by epithelial-mesenchymal transition and was associated with poor prognosis and reduced ACT efficacy. Collectively, the results of this study provide valuable insights into the microbial characteristics associated with GC prognosis and therapy efficacy.

Long noncoding RNA H19 in ovarian biology and placenta development

As the first long noncoding RNA to be discovered, H19 has gained substantial attention as a key regulator of several biological processes and its roles in female reproductive biology are gradually getting revealed. Herein, we have summarized the current evidence regarding H19 expression pattern and involvement in the developmental and pathological processes associated with the ovary and the placenta. The findings indicate that within the ovaries, H19 is expressed in the antral and cystic atretic follicles as well as in the corpora lutea but absent in the primordial, primary, and secondary follicles. Its normal expression promotes the maturation of antral follicles and prevents their premature selection for the ovulatory journey while its aberrant induction promotes polycystic ovary syndrome development and ovarian cancer metastasis. In the placenta, H19 is highly expressed in the cytotrophoblasts and extravillous trophoblasts but weakly expressed in the syncytiotrophoblast layer and potentially controls trophoblast cell fate decisions during placenta development. Abnormal expression of H19 is observed in the placental villi of pregnancies affected by pre-eclampsia and fetal growth restriction. Therefore, dysregulated H19 is a candidate biomarker and therapeutic target for the mitigation of ovarian and placenta-associated diseases.

Prediction of Chemoresistance-How Preclinical Data Could Help to Modify Therapeutic Strategy in High-Grade Serous Ovarian Cancer

High-grade serous ovarian cancer (HGSOC) is one of the most lethal tumors generally and the most fatal cancer of the female genital tract. The approved standard therapy consists of surgical cytoreduction and platinum/taxane-based chemotherapy, and of targeted therapy in selected patients. The main therapeutic problem is chemoresistance of recurrent and metastatic HGSOC tumors which results in low survival in the group of FIGO III/IV. Therefore, the prediction and monitoring of chemoresistance seems to be of utmost importance for the improvement of HGSOC management. This type of cancer has genetic heterogeneity with several subtypes being characterized by diverse gene signatures and disturbed peculiar epigenetic regulation. HGSOC develops and metastasizes preferentially in the specific intraperitoneal environment composed mainly of fibroblasts, adipocytes, and immune cells. Different HGSOC subtypes could be sensitive to distinct sets of drugs. Moreover, primary, metastatic, and recurrent tumors are characterized by an individual biology, and thus diverse drug responsibility. Without a precise identification of the tumor and its microenvironment, effective treatment seems to be elusive. This paper reviews tumor-derived genomic, mutational, cellular, and epigenetic biomarkers of HGSOC drug resistance, as well as tumor microenvironment-derived biomarkers of chemoresistance, and discusses their possible use in the novel complex approach to ovarian cancer therapy and monitoring.

Mechanisms of Regulation of the Expression of miRNAs and lncRNAs by Metformin in Ovarian Cancer

Ovarian cancer (OC) is one of the most lethal gynecological malignancies. The use of biological compounds such as non-coding RNAs (ncRNAs) is being considered as a therapeutic option to improve or complement current treatments since the deregulation of ncRNAs has been implicated in the pathogenesis and progression of OC. Old drugs with antitumoral properties have also been studied in the context of cancer, although their antitumor mechanisms are not fully clear. For instance, the antidiabetic drug metformin has shown pleiotropic effects in several in vitro models of cancer, including OC. Interestingly, metformin has been reported to regulate ncRNAs, which could explain its diverse effects on tumor cells. In this review, we discuss the mechanism of epigenetic regulation described for metformin, with a focus on the evidence of metformin-dependent microRNA (miRNAs) and long non-coding RNA (lncRNAs) regulation in OC.

Long non-coding RNA H19: a potential biomarker and therapeutic target in human malignant tumors

Long non-coding RNAs play important roles in cellular functions and disease development. H19, as a long non-coding RNA, is pervasively over-expressed in almost all kinds of human malignant tumors. Although many studies have reported that H19 is closely associated with tumor cell proliferation, apoptosis, invasion, metastasis, and chemoresistance, the role and mechanism of H19 in gene regulation and tumor development are largely unclear. In this review, we summarized the recent progress in the study of the major functions and mechanisms of H19 lncRNA in cancer development and progression. H19 possesses both oncogenic and tumor-suppressing activities, presumably through regulating target gene transcription, mRNA stability and splicing, and competitive inhibition of endogenous RNA degradation. Studies indicate that H19 may involve in cell proliferation and apoptosis, tumor initiation, migration, invasion, metastasis and chemoresistance and may serve as a potential biomarker for early diagnosis, prognosis, and novel molecular target for cancer therapy.

The Role of NQO1 in Ovarian Cancer

Ovarian cancer is one of the most dangerous gynecologic malignancies showing a high fatality rate because of late diagnosis and relapse occurrence due to chemoresistance onset. Several researchers reported that oxidative stress plays a key role in ovarian cancer occurrence, growth and development. The NAD(P)H:quinone oxidoreductase 1 (NQO1) is an antioxidant enzyme that, using NADH or NADPH as substrates to reduce quinones to hydroquinones, avoids the formation of the highly reactive semiquinones, then protecting cells against oxidative stress. In this review, we report evidence from the literature describing the effect of NQO1 on ovarian cancer onset and progression.

Glutamate-cysteine ligase catalytic and its modifier function as novel immunotargets in gastric adenocarcinoma

OBJECTIVES

To determine the expression and function of glutamate-cysteine ligase catalytic (GCLC) and glutamate-cysteine ligase catalytic modifier (GCLM) in gastric adenocarcinoma.

METHODS

Bioinformatics was used to analyze the expression of GCLC and GCLM. We download and analyzed the expression of gastric adenocarcinoma patients from TCGA database. Moreover, the method of immunochemistry was used to verify the expression of GCLC and GCLM in gastric adenocarcinoma.

RESULTS

At first, the expression of GCLC and GCLM in gastric adenocarcinoma tissues were both significantly higher compared with normal tissues analyzed via TCGA database. Then, gastric adenocarcinoma tissues were collected and performed with immunochemistry. The gastric adenocarcinoma with positive staining for GCLC and GCLM was 77% and 80%, respectively, which was significantly higher compared with adjacent normal tissues (9% and 11%, respectively).

CONCLUSIONS

The disordered expression of GCLC and GCLM in gastric adenocarcinoma suggested that these factors may induce tumorigenesis and may be a novel target for diagnosis and treatment of gastric adenocarcinoma.

A Platinum Resistance-Related lncRNA Signature for Risk Classification and Prognosis Prediction in Patients with Serous Ovarian Cancer

Accurate risk stratification for patients with serous ovarian cancer (SOC) is pivotal for treatment decisions. In this study, we identified a lncRNA-based signature for predicting platinum resistance and prognosis stratification for SOC patients. We analyzed the RNA-sequencing data and the relevant clinical information of 295 SOC samples obtained from The Cancer Genome Atlas (TCGA) database and 180 normal ovarian tissues from the Genotype-Tissue Expression (GTEx) database. A total of 284 differentially expressed lncRNAs were screened out between platinum-sensitive and platinum-resistant groups by univariate Cox regression analysis. Then, a signature consisting of eight prognostic lncRNAs was used to construct a lncRNA score model by least absolute shrinkage and selection operator (LASSO) regression and multivariate Cox regression analysis. The ROC analysis showed that this signature had a good predictive performance for chemotherapy response in the training set (AUC = 0.8524) and the testing and whole sets with 0.8142 and 0.8393 of AUC, respectively. Dichotomized by the risk score of lncRNAs (lncScore), the high-risk patients showed significantly shorter progression-free survival (PFS) and overall survival (OS). Based on the final Cox model, a nomogram comprising the 8-lncRNA signature and 3 clinicopathological risk factors was then established for clinical application to predict the 1, 2, and 3-year PFS of SOC patients. The gene set enrichment analysis (GSEA) revealed that genes in the high-risk group were active in ATP synthesis, coupled electron transport, and mitochondrial respiratory chain complex assembly. Overall, our findings demonstrated the potential clinical significance of the 8-lncRNA-based classifier as a novel biomarker for outcome prediction and therapy decisions in SOC patients with platinum treatment.

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.

Blockade of ALDH in Cisplatin-Resistant Ovarian Cancer Stem Cells In Vitro Synergistically Enhances Chemotherapy-Induced Cell Death

Epithelial ovarian cancer (EOC) is the leading cause of gynecological cancer-related death. The high mortality and morbidity associated with EOC are mostly due to late diagnosis and chemotherapy drug resistance. Currently, the standard first-line chemotherapy regimen is systemic administration of platinum-based chemotherapy combined with a taxane. A major problem besides cisplatin resistance (occurring in nearly one-third of patients) is the greater toxicity of the drug combinations. A synergistic treatment with drug supporting activity could maximize the cytotoxic effects of chemotherapeutic agents on tumor cells while decreasing the dosage of each drug to potentially reduce toxicity. The ALDH-blocking agent Disulfiram (DSF), a clinically approved drug used for alcoholism treatment, has displayed promising anti-cancer activity. We previously described that blocking ALDH activity enhances the induction of apoptosis, especially in ovarian cancer stem cells treated with chemotherapeutic agents. In this study, we further investigated the synergistic effect of DSF in combination with cytotoxic chemotherapeutic drugs. The concentration of each chemotherapeutic agent could be significantly reduced with sustained efficacy on tumor cell apoptosis in cell lines in vitro (Dose-Reduction Index at IC₅₀ from 1 to 50). Moreover, the potential chemo-sensitizing effects of DSF on ALDH-associated cisplatin-resistant ovarian cancer stem cells were also investigated and shown that in contrast to its high resistance to cisplatin, the cisplatin-resistant cells remain very sensitive to DSF-induced cytotoxicity (apoptosis and necrosis: cisplatin-resistant cells vs. parental cells: 60.4% vs. 20.5%). In combination with DSF and cisplatin, relatively more apoptosis and necrosis were induced in cisplatin-resistant cells than in their parental cells (apoptosis and necrosis: cisplatin-resistant cells vs. parental cells: 81.5% vs. 50.1%). A transcriptome analysis identified that ALDH was mainly enriched in the cancer-associated fibroblasts and showed that ALDH plays roles in responding to oxidative stress, metabolisms, and energy transition in the ALDH-associated cisplatin-resistant ovarian cancer stem cells. In conclusion, our data demonstrate a key role of ALDH-associated cisplatin-resistant cancer stem cells and identifies DSF as a potential adjuvant for a rational protocol design by computational quantitative assessment in vitro on ovarian cancer cell lines. Our work contributes to resolving the ALDH-associated cisplatin resistance and provides a resource for the development of novel chemotherapeutic regimens.

Role of NRF2 in Ovarian Cancer

Among gynaecologic malignancies, ovarian cancer is one of the most dangerous, with a high fatality rate and relapse due to the occurrence of chemoresistance. Many researchers demonstrated that oxidative stress is involved in tumour occurrence, growth and development. Nuclear factor erythroid 2-related factor 2 (NRF2) is an important transcription factor, playing an important role in protecting against oxidative damage. Increased levels of Reactive Oxygen Species (ROS) activate NRF2 signalling, inducing the expression of antioxidant enzymes, such as haem oxygenase (HO-1), catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD), that protect cells against oxidative stress. However, NRF2 activation in cancer cells is responsible for the development of chemoresistance, inactivating drug-mediated oxidative stress that normally leads to cancer cells’ death. In this review, we report evidence from the literature describing the effect of NRF2 on ovarian cancer, with a focus on its function in drug resistance, NRF2 natural and synthetic modulators and its protective function in normal ovarian preservation.

Synergistic effect of Tripterygium glycosides and cisplatin on drug-resistant human epithelial ovarian cancer via ILK/GSK3β/Slug signal pathway

The side-effects of therapeutic drugs and the intrinsic or acquired cisplation resistance are considered impediments in the clinic treatment of human epithelial ovarian cancer, which contribute heavily to the startlingly high mortality. It is imperative to look for drugs to inhibit cancer and minimize the chemotherapy resistance safely and effectively from the Chinese herbal medicine. In the present study, we evaluated the anti-cancer effect of Tripterygium glycosides (GTW) and its sensitizing effect with cisplation (DDP) both in vitro and in vivo. The 5-ethynyl-2'-deoxyuridine (EdU) proliferation assay, transwell assay, and scratch wound healing assay demonstrated that GTW and DDP+GTW prominently inhibited the proliferation, migration, and invasion of SKOV3/DDP cells. In addition, treatment using GTW and DDP+GTW for 24 h significantly decreased the expression of ILK, p-AKT, p-GSK3β, N-Cadherin, and Slug, and markedly enhanced the expression of E-cadherin. Moreover, animal results confirmed that GTW and DDP+GTW significantly inhibited the tumor volume, increased the apoptosis of tumors cells and reduced the production of tumor markers CA125 and HE4 in mice serum. Similar to the results in vitro, GTW and DDP+GTW significantly inhibited the expression of proteins in epithelial-mesenchymal transition (EMT) and ILK/GSK3β/Slug signal pathway in tumors in vivo. In conclusion, our results indicated that GTW may be served as a potential therapeutic drug combination with DDP to treat drug resistant ovarian cancer via regulating ILK/GSK3β/Slug signal pathway.

Effective Inhibition of Mitochondrial Metabolism by Cryptotanshinone in MDA-MB231 cells: A Proteomic Analysis

Background :

Triple-negative breast cancer (TNBC) is a subtype of invasive cancer in breast with the symptoms of unfavourable prognosis and limited targeted treatment options. Evidence of changes in the metabolic status of TNBC, characterised by increased glycolysis, mitochondrial oxidative phosphorylation, as well as production and utilization of tricarboxylic acid cycle intermediates.

Objective:

Investigate the proteins altered in cryptotanshinone treated MDA-MB-231 cells and explore the key pathways and specific molecular markers involved in cryptotanshinone treatment.

Method:

We use unlabeled quantitative proteomics to gain insight into the anticancer mechanism of cryptotanshinone on MDA-MB231 triple negative breast cancer cells. And flow cytometry was used to detect apoptosis and changes in cell mitochondrial membrane potential.

Results:

We show that inhibiting the expression of electron transport chain complex proteins, also inhibits mitochondrial oxidative phosphorylation. Additionally, down-regulation of the ribosime biogenesis pathway was found to inhibit cell metabolism.

Conclusion:

In summary, results show that cryptotanshinone can trigger rapid and irreversible apoptosis in MDA-MB-231 cells through effectively inhibiting cell metabolism.

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.

(In)Distinctive Role of Long Non-Coding RNAs in Common and Rare Ovarian Cancers

Rare ovarian cancers (ROCs) are OCs with an annual incidence of fewer than 6 cases per 100,000 women. They affect women of all ages, but due to their low incidence and the potential clinical inexperience in management, there can be a delay in diagnosis, leading to a poor prognosis. The underlying causes for these tumors are varied, but generally, the tumors arise due to alterations in gene/protein expression in cellular processes that regulate normal proliferation and its checkpoints. Dysregulation of the cellular processes that lead to cancer includes gene mutations, epimutations, non-coding RNA (ncRNA) regulation, posttranscriptional and posttranslational modifications. Long non-coding RNA (lncRNA) are defined as transcribed RNA molecules, more than 200 nucleotides in length which are not translated into proteins. They regulate gene expression through several mechanisms and therefore add another level of complexity to the regulatory mechanisms affecting tumor development. Since few studies have been performed on ROCs, in this review we summarize the mechanisms of action of lncRNA in OC, with an emphasis on ROCs.

The Emerging Role of Non-coding RNAs in Drug Resistance of Ovarian Cancer

Ovarian cancer is one of the most common gynecological malignancies with highest mortality rate among all gynecological malignant tumors. Advanced ovarian cancer patients can obtain a survival benefit from chemotherapy, including platinum drugs and paclitaxel. In more recent years, the administration of poly-ADP ribose polymerase inhibitor to patients with BRCA mutations has significantly improved the progression-free survival of ovarian cancer patients. Nevertheless, primary drug resistance or the acquisition of drug resistance eventually leads to treatment failure and poor outcomes for ovarian cancer patients. The mechanism underlying drug resistance in ovarian cancer is complex and has not been fully elucidated. Interestingly, different non-coding RNAs (ncRNAs), such as circular RNAs, long non-coding RNAs and microRNAs, play a critical role in the development of ovarian cancer. Accumulating evidence has indicated that ncRNAs have important regulatory roles in ovarian cancer resistance to chemotherapy reagents and targeted therapy drugs. In this review, we systematically highlight the emerging roles and the regulatory mechanisms by which ncRNAs affect ovarian cancer chemoresistance. Additionally, we suggest that ncRNAs can be considered as potential diagnostic and prognostic biomarkers as well as novel therapeutic targets for ovarian cancer.

Hidden Treasures: Macrophage Long Non-Coding RNAs in Lung Cancer Progression

Ever since RNA sequencing of whole genomes and transcriptomes became available, numerous RNA transcripts without having the classic function of encoding proteins have been discovered. Long non-coding RNAs (lncRNAs) with a length greater than 200 nucleotides were considered as "junk" in the beginning, but it has increasingly become clear that lncRNAs have crucial roles in regulating a variety of cellular mechanisms and are often deregulated in several diseases, such as cancer. Lung cancer is the leading cause of cancer-related deaths and has a survival rate of less than 10%. Immune cells infiltrating the tumor microenvironment (TME) have been shown to have a great effect on tumor development with macrophages being the major cell type within the TME. Macrophages can inherit an inflammatory M1 or an anti-inflammatory M2 phenotype. Tumor-associated macrophages, which are predominantly polarized to M2, favor tumor growth, angiogenesis, and metastasis. In this review, we aimed to describe the complex roles and functions of lncRNAs in macrophages and their influence on lung cancer development and progression through the TME.

HOTTIP-miR-205-ZEB2 Axis Confers Cisplatin Resistance to Ovarian Cancer Cells

Ovarian cancer is a deadly gynecological malignancy with resistance to cisplatin a major clinical problem. We evaluated a role of long non-coding (lnc) RNA HOTTIP (HOXA transcript at the distal tip) in the cisplatin resistance of ovarian cancer cells, using paired cisplatin sensitive and resistant A2780 cells along with the SK-OV-3 cells. HOTTIP was significantly elevated in cisplatin resistant cells and its silencing reversed the cisplatin resistance of resistant cells. HOTTIP was found to sponge miR-205 and therefore HOTTIP silenced cells had higher levels of miR-205. Downregulation of miR-205 could attenuate HOTTIP-silencing effects whereas miR-205 upregulation in resistant cells was found to re-sensitize cells to cisplatin. HOTTIP silencing also led to reduced NF-κB activation, clonogenic potential and the reduced expression of stem cell markers SOX2, OCT4, and NANOG, an effect that could be attenuated by miR-205. Finally, ZEB2 was identified as the gene target of miR-205, thus completing the elucidation of HOTTIP-miR-205-ZEB2 as the novel axis which is functionally involved in the determination of cisplatin resistance in ovarian cancer cells.

Hub Long Noncoding RNAs with m6A Modification for Signatures and Prognostic Values in Kidney Renal Clear Cell Carcinoma

Background: N6-methyladenosine (m6A)–modified long noncoding RNAs (m6A-lncRNAs) have been proven to be involving in regulating tumorigenesis, invasion, and metastasis for a variety of tumors. The present study aimed to screen lncRNAs with m6A modification and investigate their biological signatures and prognostic values in kidney renal clear cell carcinoma (KIRC).

Materials and Methods: lncRNA-seq, miRNA-seq, and mRNA-seq profiles of KIRC samples and the clinical characteristics of corresponding patients were downloaded from The Cancer Genome Atlas (TCGA). The R package “edgeR” was utilized to perform differentially expressed analysis on these profiles to gain DElncRNAs, DEmiRNAs, and DEmRNAs, respectively. The results of intersection of DElncRNAs and m6A-modified genes were analyzed by the weighted gene co-expression network analysis (WGCNA) to screen hub m6A-lncRNAs. Then, WGCNA was also used to construct an lncRNA-miRNA-mRNA (ceRNA) network. The Cox regression analysis was conducted on hub m6A-lncRNAs to construct the m6A-lncRNAs prognostic index (m6AlRsPI). Receiver operating characteristic (ROC) curve was used to assess the predictive ability of m6AlRsPI. The m6AlRsPI model was tested by internal and external cohorts. The molecular signatures and prognosis for hub m6A-lncRNAs and m6AlRsPI were analyzed. The expression level of hub m6A-lncRNAs in KIRC cell lines were quantified by qRT-PCR.

Results: A total of 21 hub m6A-lncRNAs associated with tumor metastasis were identified in the light of WGCNA. The ceRNA network for 21 hub m6A-lncRNAs was developed. The Cox regression analysis was performed on the 21 hub m6A-lncRNAs, screening two m6A-lncRNAs regarded as independent prognostic risk factors. The m6AlRsPI was established based on the two m6A-lncRNAs as follows: (0.0006066 × expression level of LINC01820) + (0.0020769 × expression level of LINC02257). The cutoff of m6AlRsPI was 0.96. KM survival analysis for m6AlRsPI showed that the high m6AlRsPI group could contribute to higher mortality. The area under ROC curve for m6AlRsPI for predicting 3- and 5-year survival was 0.760 and 0.677, respectively, and the m6AlRsPI was also tested. The mutation and epithelial–mesenchymal transition (EMT) analysis for m6AlRsPI showed that the high m6AIRsPI group had more samples with gene mutation and had more likely caused EMT. Finally, gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis were performed for mRNAs interacted with the two m6A-lncRNAs, showing they were involved in the process of RNA splicing and regulation of the mRNA surveillance pathway. qRT-PCR analysis showed that the two m6A-lncRNAs were upregulated in KIRC.

Conclusion: In the present study, hub m6A-lncRNAs were determined associated with metastasis in KIRC, and the ceRNA network demonstrated the potential carcinogenic regulatory pathway. Two m6A-lncRNAs associated with the overall survival were screened and m6AlRsPI was constructed and validated. Finally, the molecular signatures for m6AlRsPI and the two m6A-lncRNAs were analyzed to investigate the potential modulated processes in KIRC.

Lipoperoxide Nanoemulsion as Adjuvant in Cisplatin Cancer Therapy: In Vitro Study on Human Colon Adenocarcinoma DLD-1 Cells

Cisplatin is a first-choice chemotherapeutic agent used to treat solid tumors even though the onset of multi-drug resistance and the time-dose side-effects impair its mono-therapeutic application. Therefore, new drug-delivery approaches, based on nanomedicine strategies, are needed to enhance its therapeutic potential in favor of a dose-reduction of cisplatin. Polyunsaturated fatty acids and their metabolism-derived intermediates, as well as lipid peroxidation end-products, are used as adjuvants to improve the effectiveness of chemotherapy. Lipid hydroperoxides, derived from the oxidation of edible oils, can contribute to cell death, generating breakdown products (e.g., reactive aldehydes). In this regard, the aim of this present study was to evaluate an invitro combinatory strategy between a lecithin-based nanoemulsion system of K600, a patented mixture of peroxidated oil and peroxidated cholesterol, and cisplatin on DLD1 human adenocarcinoma cells. Our findings showed that nanoemulsions, acting in synergy with cisplatin, improve cisplatin bioactivity, in terms of enhancing its anti-cancer activity, towards DLD1 cells. Indeed, this combination approach, whilst maintaining cisplatin at low concentrations, induces a significant reduction in DLD1 cell viability, an increase in pro-apoptotic markers, and genotoxic damage. Therefore, K600 nanoemulsions as an efficient targeted delivery system of cisplatin allow for the reduction in the chemotherapeutic agent doses.

Genome-wide DNA methylation and RNA expression differences correlate with invasiveness in melanoma cell lines

Aims & objectives: The aim of this study was to investigate the role of DNA methylation in invasiveness in melanoma cells. Materials & methods: The authors carried out genome-wide transcriptome (RNA sequencing) and reduced representation bisulfite sequencing methylome profiling between noninvasive (n = 4) and invasive melanoma cell lines (n = 5). Results: The integration of differentially expressed genes and differentially methylated fragments (DMFs) identified 12 DMFs (two in AVPI1, one in HMG20B, two in BCL3, one in NTSR1, one in SYNJ2, one in ROBO2 and four in HORMAD2) that overlapped with either differentially expressed genes (eight DMFs and six genes) or cis-targets of lncRNAs (five DMFs associated with cis-targets and four differentially expressed lncRNAs). Conclusions: DNA methylation changes are associated with a number of transcriptional differences observed in noninvasive and invasive phenotypes in melanoma.

Downregulation of lncRNA H19 sensitizes melanoma cells to cisplatin by regulating the miR-18b/IGF1 axis

Long noncoding RNAs (LncRNAs) lncRNA H19 has been shown to be involved in the chemotherapy resistance of cancer cells. However, the role of lncRNA H19 in chemotherapy resistance of melanoma cells remains unknown. Here, we determined lncRNA H19, miR-18b, and insulin-like growth factor 1 (IGF1) expression by utilizing quantitative real-time PCR. Cell proliferation ability and chemosensitivity were assessed by colony formation assay and MTT assay. Flow cytometry assay was applied to detect cell apoptosis. We discovered that lncRNA H19 was upregulated, but miR-18b was downregulated in melanoma tissues and cisplatin (DDP)-resistant melanoma cells. The overall survival for the group with lower lncRNA H19 was significantly better than the group with higher H19. IGF1 mRNA level was higher in melanoma tissues than that in normal tissues. miR-18b expression level A negative correlation was observed between the expression levels of miR-18b, lncRNA H19, and IGF1 mRNA. Functionally, knockdown of lncRNA H19 sensitized resistant A375/DDP and M8/DDP cells to DDP. Silencing lncRNA H19 inhibited colony formation ability and promoted apoptosis of DDP-resistant melanoma cells, which was abrogated by miR-18b inhibition and IGF1 upregulation. Mechanistically, lncRNA H19 directly interacted with miR-18b to regulate its expression. IGF1 was identified as a target of miR-18b. These findings highlight the fact that lncRNA H19 could influence DDP-resistance by modulating the miR-18b/IGF axis in melanoma cells, suggesting a new potential therapeutic target for melanoma patient treatment.

lncRNA LOC102724169 plus cisplatin exhibit the synergistic anti-tumor effect in ovarian cancer with chronic stress

Chronic stress has been proven to accelerate the development and progression of ovarian cancer, but the underlying molecular mechanisms have not been fully elucidated. In a combination survey of ovarian cancer with chronic stress (OCCS) mouse models and high-throughput sequencing, a key lncRNA named LOC102724169 on chromosome 6q27 has been identified, which functions as a dominant tumor suppressor in OCCS. Transcriptionally regulated by CCAAT enhancer binding protein (CEBP) beta (CEBPB), LOC102724169 shows low expression and correlates with poor progression-free survival (PFS) in OCCS patients. LOC102724169 is an instructive molecular inhibitor of malignancy of ovarian cancer cells, which is necessary to improve the curative effect of cisplatin therapy on ovarian cancer. This function stems from the inactivation of molecules in phosphatidylinositol 3-kinase (PI3K)/AKT signaling, repressing MYB expression and retaining the responsiveness of cancer cells to cisplatin. These findings provide a mechanistic understanding of the synergistic anti-tumor purpose of LOC102724169 as a bona fide tumor suppressor, enhancing the therapeutic effect of cisplatin. The new regulatory model of “lncRNA-MYB” provides new perspectives for LOC102724169 as a chronic stress-related molecule and also provides mechanistic insight into exploring the cancer-promoting mechanism of MYB in OCCS, which may be a promising therapeutic strategy for ovarian cancer.

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.

On-tissue polysulfide visualization by surface-enhanced Raman spectroscopy benefits patients with ovarian cancer to predict post-operative chemosensitivity

Chemosensitivity to cisplatin derivatives varies among individual patients with intractable malignancies including ovarian cancer, while how to unlock the resistance remain unknown. Ovarian cancer tissues were collected the debulking surgery in discovery- (n = 135) and validation- (n = 47) cohorts, to be analyzed with high-throughput automated immunohistochemistry which identified cystathionine γ-lyase (CSE) as an independent marker distinguishing non-responders from responders to post-operative platinum-based chemotherapy. We aimed to identify CSE-derived metabolites responsible for chemoresistant mechanisms: gold-nanoparticle (AuN)-based surface-enhanced Raman spectroscopy (SERS) was used to enhance electromagnetic fields which enabled to visualize multiple sulfur-containing metabolites through detecting scattering light from Au-S vibration two-dimensionally. Clear cell carcinoma (CCC) who turned out less sensitive to cisplatin than serous adenocarcinoma was classified into two groups by the intensities of SERS intensities at 480 cm^-1; patients with greater intensities displayed the shorter overall survival after the debulking surgery. The SERS signals were eliminated by topically applied monobromobimane that breaks sulfane-sulfur bonds of polysulfides to result in formation of sulfodibimane which was detected at 580 cm^-1, manifesting the presence of polysulfides in cancer tissues. CCC-derived cancer cell lines in culture were resistant against cisplatin, but treatment with ambroxol, an expectorant degrading polysulfides, renders the cells CDDP-susceptible. Co-administration of ambroxol with cisplatin significantly suppressed growth of cancer xenografts in nude mice. Furthermore, polysulfides, but neither glutathione nor hypotaurine, attenuated cisplatin-induced disturbance of DNA supercoiling. Polysulfide detection by on-tissue SERS thus enables to predict prognosis of cisplatin-based chemotherapy. The current findings suggest polysulfide degradation as a stratagem unlocking cisplatin chemoresistance.

H19/miR-107/HMGB1 axis sensitizes laryngeal squamous cell carcinoma to cisplatin by suppressing autophagy in vitro and in vivo

Laryngeal squamous cell carcinoma (LSCC) is the most common malignant tumor, which occurs in the head and neck. Current treatments for LSCC are all largely weakened by increasing drug resistance. Our study aimed to investigate the effects of long noncoding RNA (lncRNA) H19 on drug resistance in LSCC. In our study, we found that the level of H19 was sharply upregulated in LSCC tissues and drug-resistant cells compared with the control. Besides, the expression of high-mobility group B1 (HMGB1) was elevated, and microRNA107 (miR-107) was suppressed in drug-resistant cells compared with the control. Further study revealed that the interference of H19 by short hairpin RNA (shRNA) effectively suppressed high autophagy level and obvious drug resistance in drug-resistant cells. Besides that, miR-107 was predicted as a target of H19 and inhibiting effects of H19 shRNA on autophagy and drug resistance were both reversed by miR-107 inhibitor. Moreover, HMGB1 was predicted as a target of miR-107 in LSCC cells and knockdown of HMGB1 was able to suppress autophagy and drug resistance in LSCC cells. In addition, our investigation demonstrated that H19 shRNA exerted an inhibiting effect on autophagy and drug resistance by downregulating HMGB1 by targeting miR-107. Finally, the in vivo experiment revealed that LV-H19 shRNA strongly suppressed drug resistance compared with the usage of cisplatin individually. Taken together, our research indicated an H19-miR-107-HMGB1 axis in regulating the autophagy-induced drug resistance in LSCC in vitro and in vivo, providing novel targets for molecular-targeted therapy and broadening the research for LSCC.

Comprehensive characterization of a drug-resistance-related ceRNA network across 15 anti-cancer drug categories

Cancer is still a major health problem around the world. The treatment failure of cancer has largely been attributed to drug resistance. Competitive endogenous RNAs (ceRNAs) are involved in various biological processes and thus influence the drug sensitivity of cancers. However, a comprehensive characterization of drug-sensitivity-related ceRNAs has not yet been performed. In the present study, we constructed 15 ceRNA networks across 15 anti-cancer drug categories, involving 217 long noncoding RNAs (lncRNAs), 158 microRNAs (miRNAs), and 1,389 protein coding genes (PCGs). We found that these ceRNAs were involved in hallmark processes such as “self-sufficiency in growth signals,” “insensitivity to antigrowth signals,” and so on. We then identified an intersection ceRNA network (ICN) across the 15 anti-cancer drug categories. We further identified interactions between genes in the ICN and clinically actionable genes (CAGs) by analyzing the co-expressions, protein-protein interactions, and transcription factor-target gene interactions. We found that certain genes in the ICN are correlated with CAGs. Finally, we found that genes in the ICN were aberrantly expressed in tumors, and some were associated with patient survival time and cancer stage.

LncRNA H19 Suppresses Osteosarcomagenesis by Regulating snoRNAs and DNA Repair Protein Complexes

Osteosarcoma is one of the most frequent common primary malignant tumors in childhood and adolescence. Long non-coding RNAs (lncRNAs) have been reported to regulate the initiation and progression of tumors. However, the exact molecular mechanisms involving lncRNA in osteosarcomagenesis remain largely unknown. Li-Fraumeni syndrome (LFS) is a familial cancer syndrome caused by germline p53 mutation. We investigated the tumor suppressor function of lncRNA H19 in LFS-associated osteosarcoma. Analyzing H19-induced transcriptome alterations in LFS induced pluripotent stem cell (iPSC)-derived osteoblasts, we unexpectedly discovered a large group of snoRNAs whose expression was significantly affected by H19. We identified SNORA7A among the H19-suppressed snoRNAs. SNORA7A restoration impairs H19-mediated osteogenesis and tumor suppression, indicating an oncogenic role of SNORA7A. TCGA analysis indicated that SNORA7A expression is associated with activation of oncogenic signaling and poor survival in cancer patients. Using an optimized streptavidin-binding RNA aptamer designed from H19 lncRNA, we revealed that H19-tethered protein complexes include proteins critical for DNA damage response and repair, confirming H19's tumor suppressor role. In summary, our findings demonstrate a critical role of H19-modulated SNORA7A expression in LFS-associated osteosarcomas.

Long non-coding RNAs in recurrent ovarian cancer: Theranostic perspectives

Nearly 70% of ovarian cancer (OC) patients experience recurrence within the first 2 years after initial treatment. Emerging evidence indicates that long non-coding RNAs (lncRNAs) play a pivotal role in the pathogenesis of OC progression, resistance to therapy and recurrent OC (ROC). Transcriptome profiling studies have reported differential expression patterns of lncRNAs in OC which are related to increased cell invasion, metastasis and drug resistance. In this review, we highlighted the roles of lncRNAs in OC progression and outlined the potential molecular mechanisms by which lncRNAs impact on ROC. Recent advances using lncRNAs as potential biomarkers for screening, detection, prediction, response to therapy and as therapeutic targets are discussed.

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.

Oxidative Stress and Cancer Development: Are Noncoding RNAs the Missing Links?

Significance: It is now clear that genetic changes underlie the basis of cancer, and alterations in functions of multiple genes are responsible for the process of tumorigenesis. Besides the classical genes that are usually implicated in cancer, the role of noncoding RNAs (ncRNAs) and reactive oxygen species (ROS) as independent entitites has also been investigated. Recent Advances: The microRNAs and long noncoding RNAs (lncRNAs), two main classes of ncRNAs, are known to regulate many aspects of tumor development. ROS, generated during oxidative stress and pathological conditions, are known to regulate every step of tumor development. Conversely, oxidative stress and ROS producing agents can suppress tumor development. The malignant cells normally produce high levels of ROS compared with normal cells. The interaction between ROS and ncRNAs regulates the expression of multiple genes and pathways implicated in cancer, suggesting a unique mechanistic relationship among ncRNA-ROS-cancer. The mechanistic relationship has been reported in hepatocellular carcinoma, glioma, and malignancies of blood, breast, colorectum, esophagus, kidney, lung, mouth, ovary, pancreas, prostate, and stomach. The ncRNA-ROS regulate several cancer-related cell signaling pathways, namely, protein kinase B (AKT), epidermal growth factor receptor (EGFR), forkhead box O3 (FOXO3), kelch-like ECH-associated protein 1 (Keap1), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), nuclear factor erythroid 2-related factor 2 (Nrf2), p53, phosphatase and tensin homologue (PTEN), and wingless-related integration site (Wnt)/glycogen synthase kinase-3 beta (GSK3β). Critical Issues: To date, most of the reports about ncRNA-oxidative stress-carcinogenesis relationships are based on cell lines. The mechanistic basis for this relationship has not been completely elucidated. Future Directions: Attempts should be made to explore the association of lncRNAs with ROS. The significance of the ncRNA-oxidative stress-carcinogenesis interplay should also be explored through studies in animal models.

Endometriosis and ovarian cancer risk, an epigenetic connection

Endometriosis is a gynecological disorder that affects 176 million women worldwide and 1 in 10 females in the United States. Endometriosis most often affects women of child-bearing age, with most going undiagnosed. Endometriosis also shares many characteristics common to invasive cancer and has been known to be associated with epithelial ovarian cancer. Ovarian cancer is the 11^th most common cancer among women and over 22,000 new cases will be diagnosed within the next year. Women most commonly diagnosed with this cancer are between the ages of 55–64 years, outside the range of the age of women affected with endometriosis. While no known cause of either disease has been established, epigenetic regulation is thought to play a major role in both. This review focuses on epigenetic changes that occur within each individual disease as well as those that are similar in both, suggesting a possible etiological link between the two diseases.

Revisiting chemoresistance in ovarian cancer: Mechanism, biomarkers, and precision medicine

Among the gynecological cancers, ovarian cancer is the most lethal. Its therapeutic options include a combination of chemotherapy with platinum-based compounds and cytoreductive surgery. Most ovarian cancer patients exhibit an initial response to platinum-based therapy, however, platinum resistance has led to up to 80% of this responsive cohort becoming refractory. Ovarian cancer recurrence and drug resistance to current chemotherapeutic options is a global challenge. Chemo-resistance is a complex phenomenon that involves multiple genes and signal transduction pathways. Therefore, it is important to elucidate on the underlying molecular mechanisms involved in chemo-resistance. This inform decisions regarding therapeutic management and help in the identification of novel and effective drug targets. Studies have documented the individual biomarkers of platinum-resistance in ovarian cancer that are potential therapeutic targets. This review summarizes the molecular mechanisms of platinum resistance in ovarian cancer, novel drug targets, and clinical outcomes.

Long non-coding RNA SNHG9 inhibits ovarian cancer progression by sponging microRNA-214-5p

Ovarian cancer ranks 7th among the most common cancer types affecting women worldwide. A number of studies have confirmed that multiple long non-coding RNAs participate in the occurrence and progression of ovarian cancer. Small nucleolar RNA host gene 9 (SNHG9) serves a role in the progression of glioblastoma and pancreatic cancer. However, the specific biological function of SNHG9 in ovarian cancer has not yet been fully investigated. The present study aimed to determine the biological role and potential molecular mechanism underlying the influence of SNHG9 in ovarian cancer. SNHG9 expression in ovarian cancer cell lines and tissues were measured via reverse transcription-quantitative PCR analysis, and cell proliferation was detected via Cell Counting Kit-8 and colony formation assays. Flow cytometry was performed to assess cell cycle progression, and Transwell and wound healing assays were performed to assess cell invasion and migration abilities. Bioinformatics software was utilized to determine the target genes of SNHG9, which were subsequently verified via dual-luciferase reporter and RNA immunoprecipitation assays. The results demonstrated that SNHG9 expression was remarkably lower in ovarian cancer cell lines and tissues compared with the negative controls. Cell function assays demonstrated that decreased SNHG9 expression notably induced the migration, colony formation, proliferation and invasiveness of ovarian cancer cells. Furthermore, the inhibitory effect of SNHG9 on the migration, colony formation, proliferation and invasion of ovarian cancer cells was partially reversed by miR-214-5p upregulation. Thus, taken together, the current results suggest that SNHG9 may serve as a tumor suppressor gene in ovarian cancer by regulating the miR-214-5p/cryptochrome circadian regulator 2 axis.

Revisiting cancer hallmarks: insights from the interplay between oxidative stress and non-coding RNAs

Cancer is one of the most common disease worldwide, with complex changes and certain traits which have been described as “The Hallmarks of Cancer.” Despite increasing studies on in-depth investigation of these hallmarks, the molecular mechanisms associated with tumorigenesis have still not yet been fully defined. Recently, accumulating evidence supports the observation that microRNAs and long noncoding RNAs (lncRNAs), two main classes of noncoding RNAs (ncRNAs), regulate most cancer hallmarks through their binding with DNA, RNA or proteins, or encoding small peptides. Reactive oxygen species (ROS), the byproducts generated during metabolic processes, are known to regulate every step of tumorigenesis by acting as second messengers in cancer cells. The disturbance in ROS homeostasis leads to a specific pathological state termed “oxidative stress”, which plays essential roles in regulation of cancer progression. In addition, the interplay between oxidative stress and ncRNAs is found to regulate the expression of multiple genes and the activation of several signaling pathways involved in cancer hallmarks, revealing a potential mechanistic relationship involving ncRNAs, oxidative stress and cancer. In this review, we provide evidence that shows the essential role of ncRNAs and the interplay between oxidative stress and ncRNAs in regulating cancer hallmarks, which may expand our understanding of ncRNAs in the cancer development from the new perspective.

Serum LUCAT1 implicates the pathogenesis of muscle-invasive bladder cancer via targeting miR-199a-5p and miR-199b-5p

Muscle-invasive bladder cancer (MIBC) is a common malignancy of urinary system cancers, accounting for about 1/3 of all newly diagnosed bladder cancer cases. Due to its strong metastasis, the 5-year survival of MIBC is less than 50%, and in serious cases, the overall survival of metastatic bladder cancer patients is about 1.3 years. LncRNAs, a type of non-coding RNAs defined as the transcripts exceeding 200 nucleotides in length, are frequently aberrant in multiple cancers including cervical, ovarian, breast and bladder cancers. Recently, LUCAT1 (short for lung cancer-associated transcript 1), a lncRNA first reported to be involved in smoking-related lung cancer, has been observed to exhibit crucial roles in the epithelial-to-mesenchymal transition (EMT), migration and invasion processes of clear cell renal cell carcinoma (ccRCC) and colorectal cancer. However, whether it involves in the pathogenesis of MIBC remains underexplored. In the present study, LUCAT1 was up-regulated in the serum samples of MIBC patients and bladder cancer cell lines, as assessed using real-time PCR. Our in vitro data (including wound healing and trans-well assays) showed that LUCAT1 was required for the proliferation, EMT, migration and invasion processes of T24 cells. Moreover, LUCAT1 directly targeted miR-199a-5p and miR-199b-5p, as affirmed using the luciferase reporter assay, and manipulation of LUCAT1 significantly suppressed miR-199a-5p and miR-199b-5p. Collectively, our findings highlight an axis of LUCAT1/miR-199a/b-5p in MIBC pathogenesis. Therefore, LUCAT1 may possibly be a promising candidate for diagnostic biomarker and therapeutic target of MIBC.

Back to the Future: Rethinking the Great Potential of lncRNAS for Optimizing Chemotherapeutic Response in Ovarian Cancer

Ovarian cancer (OC) is one of the most fatal cancers in women worldwide. Currently, platinum- and taxane-based chemotherapy is the mainstay for the treatment of OC. Yet, the emergence of chemoresistance results in therapeutic failure and significant relapse despite a consistent rate of primary response. Emerging evidence substantiates the potential role of lncRNAs in determining the response to standard chemotherapy in OC. The objective of this narrative review is to provide an integrated, synthesized overview of the current state of knowledge regarding the role of lncRNAs in the emergence of resistance to platinum- and taxane-based chemotherapy in OC. In addition, we sought to develop conceptual frameworks for harnessing the therapeutic potential of lncRNAs in strategies aimed at enhancing the chemotherapy response of OC. Furthermore, we offered significant new perspectives and insights on the interplay between lncRNAs and the molecular circuitries implicated in chemoresistance to determine their impacts on therapeutic response. Although this review summarizes robust data concerning the involvement of lncRNAs in the emergence of acquired resistance to platinum- and taxane-based chemotherapy in OC, effective approaches for translating these lncRNAs into clinical practice warrant further investigation.

Long non‑coding RNA LUCAT1 contributes to cisplatin resistance by regulating the miR‑514a‑3p/ULK1 axis in human non‑small cell lung cancer

Drug resistance is a major obstacle in the therapy of malignant tumors, including non-small cell lung cancer (NSCLC). Long non-coding RNAs (lncRNAs) have been demonstrated to be involved in chemoresistance. The present study aimed to investigate the role of lung cancer-associated transcript 1 (LUCAT1) in cisplatin (DDP) resistance in NSCLC. By using reverse transcription-quantitative polymerase chain reaction (RT-qPCR), it was found that the expression of LUCAT1 was elevated and that of microRNA-514a-3p (miR-514a-3p) was decreased in DDP-resistant NSCLC tissues and cells. Functionally, LUCAT1 upregulation enhanced cisplatin resistance by promoting the viability, autophagy and metastasis, and inhibiting the apoptosis of NSCLC cells, as demonstrated by Cell Counting kit-8 (CCK-8) assay, western blot analysis, Transwell assay and flow cytometric analysis. LUCAT1 was identified as a sponge of miR-514a-3p and uncoordinated-51-like kinase 1 (ULK1) was proven to be a target gene of miR-514a-3p by bioinformatics analysis, dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. The enhancing effect of miR-514a-3p on cisplatin sensitivity was reversed by the elevation of LUCAT1. ULK1 knockdown suppressed cisplatin resistance, while this effect was attenuated by miR-514a-3p inhibition. Moreover, LUCAT1 positively regulated ULK1 expression by targeting miR-514a-3p. In addition, LUCAT1 knockdown suppressed tumor growth in vivo. On the whole, the findings of the present study demonstrate that LUCAT1 contributes to the resistance of NSCLC cells to cisplatin by regulating the miR-514a-3p/ULK1 axis, elucidating a novel regulatory network in cisplatin resistance in NSCLC.

The role of long non-coding RNAs in drug resistance of cancer

Long non-coding RNAs (lncRNAs), a class of long RNAs, are longer than 200 nucleotides in length but lack protein-coding capacity. LncRNAs, as critical genomic regulators, are involved in genomic imprinting regulation, histone modification and gene expression regulation as well as tumor initiation and progression. However, it is also found that lncRNAs are associated with drug resistance in several types of cancer. Drug resistance is an important reason for clinical chemotherapy failure, and the molecular mechanism of tumor resistance is complex, which is a process of multi-cause, multi-gene and multi-signal transduction pathway interaction. Then comprehending the mechanisms of chemoresistance will help find ways to control the tumor progression effectively. Therefore, in this review, we will construct lncRNAs /drug resistance interaction network and shed light on the role of lncRNAs in drug resistance.

lncRNA and Mechanisms of Drug Resistance in Cancers of the Genitourinary System

Available systemic treatment options for cancers of the genitourinary system have experienced great progress in the last decade. However, a large proportion of patients eventually develop resistance to treatment, resulting in disease progression and shorter overall survival. Biomarkers indicating the increasing resistance to cancer therapies are yet to enter clinical routine. Long non-coding RNAs (lncRNA) are non-protein coding RNA transcripts longer than 200 nucleotides that exert multiple types of regulatory functions of all known cellular processes. Increasing evidence supports the role of lncRNAs in cancer development and progression. Additionally, their involvement in the development of drug resistance across various cancer entities, including genitourinary malignancies, are starting to be discovered. Consequently, lncRNAs have been suggested as factors in novel therapeutic strategies to overcome drug resistance in cancer. In this review, the existing evidences on lncRNAs and their involvement in mechanisms of drug resistance in cancers of the genitourinary system, including renal cell carcinoma, bladder cancer, prostate cancer, and testicular cancer, will be highlighted and discussed to facilitate and encourage further research in this field. We summarize a significant number of lncRNAs with proposed pathways in drug resistance and available reported studies.

Crosstalk between noncoding RNAs and ferroptosis: new dawn for overcoming cancer progression

Cancer progression including proliferation, metastasis, and chemoresistance has become a serious hindrance to cancer therapy. This phenomenon mainly derives from the innate insensitive or acquired resistance of cancer cells to apoptosis. Ferroptosis is a newly discovered mechanism of programmed cell death characterized by peroxidation of the lipid membrane induced by reactive oxygen species. Ferroptosis has been confirmed to eliminate cancer cells in an apoptosis-independent manner, however, the specific regulatory mechanism of ferroptosis is still unknown. The use of ferroptosis for overcoming cancer progression is limited. Noncoding RNAs have been found to play an important roles in cancer. They regulate gene expression to affect biological processes of cancer cells such as proliferation, cell cycle, and cell death. Thus far, the functions of ncRNAs in ferroptosis of cancer cells have been examined, and the specific mechanisms by which noncoding RNAs regulate ferroptosis have been partially discovered. However, there is no summary of ferroptosis associated noncoding RNAs and their functions in different cancer types. In this review, we discuss the roles of ferroptosis-associated noncoding RNAs in detail. Moreover, future work regarding the interaction between noncoding RNAs and ferroptosis is proposed, the possible obstacles are predicted and associated solutions are put forward. This review will deepen our understanding of the relationship between noncoding RNAs and ferroptosis, and provide new insights in targeting noncoding RNAs in ferroptosis associated therapeutic strategies.