Long noncoding RNA ZEB1-AS1 affects paclitaxel and cisplatin resistance by regulating MMP19 in epithelial ovarian cancer cells

LncRNAs in modulating cancer cell resistance to paclitaxel (PTX) therapy

Paclitaxel (PTX) is widely used for treating several cancers, including breast, ovarian, lung, esophageal, gastric, pancreatic, and neck cancers. Despite its clinical utility, cancer recurrence frequently occurs in patients due to the development of resistance to PTX. Resistance mechanisms in cancer cells treated with PTX include alterations in β-tubulin, the target molecule involved in mitosis, activation of molecular pathways enabling drug efflux, and dysregulation of apoptosis-related proteins. Long non-coding RNAs (lncRNAs), which are RNA molecules longer than 200 nucleotides without protein-coding potential, serve diverse regulatory roles in cellular processes. Increasing evidence highlights the involvement of lncRNAs in cancer progression and their contribution to PTX resistance across various cancers. Consequently, lncRNAs have emerged as potential therapeutic targets for addressing drug resistance in cancer treatment. This review focuses on the current understanding of lncRNAs and their role in drug resistance mechanisms, aiming to encourage further investigation in this area. Key lncRNAs and their associated pathways linked to PTX resistance will be summarized.

Nucleus-targeted Silencer nanoplatform regulating ZEB1-AS1 in head and neck squamous cell carcinoma therapy

Long noncoding RNAs have emerged as key players in the progression of head and neck squamous cell carcinoma (HNSC). Among them, ZEB1-AS1 was identified as an upregulated candidate in HNSC through comprehensive analysis of RNA-sequencing datasets. Here, elevated ZEB1-AS1 expression was correlated with poor prognosis in HNSC patients. Further investigations demonstrated that downregulation of ZEB1-AS1 induced epithelial-mesenchymal transition and increased sensitivity to cisplatin in Cal27 cells, while its upregulation reversed these effects, underscoring its pivotal role in tumor metastasis and cisplatin resistance in Cal27 cells. Mechanistically, ZEB1-AS1, located in cytoplasm and nucleus, directly regulated the expression of ZEB1, thereby influencing the expression of μ opioid receptor (MOR) and implicating in cancer progression. To advance clinical translation, we employed a nucleus-targeting nanoparticle platform for efficient delivery of a mixture of antisense oligonucleotides and siRNA (Silencer), effectively manipulating ZEB1-AS1 expression in vitro and in vivo. Besides, a predictive model for HNSC patients was developed by analyzing the expression levels of ZEB1-AS1, ZEB1, and MOR in the HNSC datasets. Our study underscored the critical role of ZEB1-AS1 in HNSC and its potential as a therapeutic target. By elucidating its functional mechanisms and utilizing a nucleus-targeting nanoparticle platform for efficient delivery, we proved the potential of ZEB1-AS1-targeted therapies in HNSC.

Matrix metalloproteinases as the critical regulators of cisplatin response and tumor cell invasion

Cisplatin (CDDP) as one of the most common first-line chemotherapy drugs plays a vital role in the treatment of a wide range of malignant tumors. Nevertheless, CDDP resistance is observed as a therapeutic challenge in a large number of cancer patients. Considering the CDDP side effects in normal tissues, predicting the CDDP response of cancer patients can significantly help to choose the appropriate therapeutic strategy. In this regard, investigating the molecular mechanisms involved in CDDP resistance can lead to the introduction of prognostic markers in cancer patients. Matrix metalloproteinases (MMPs) have critical roles in tissue remodeling and cell migration through extracellular matrix degradation. Therefore, defects in MMPs functions can be associated with tumor metastasis and chemo resistance. In the present review, we discussed the role of MMPs in CDDP response and tumor cell invasion. PubMed, Scopus, Google Scholar, and Web of Science were searched using "MMP", "cisplatin", and "cancer" keywords for data retrieval that was limited to Apr 20, 2024. It has been reported that MMPs can increase CDDP resistance in tumor cells as the effectors of PI3K/AKT, MAPK, and NF-κB signaling pathways or independently through the regulation of structural proteins, autophagy, and epithelial-to-mesenchymal transition (EMT) process. This review has an effective role in introducing MMPs as the prognostic markers and therapeutic targets in CDDP-resistant cancer patients.

Ten Hypermethylated lncRNA Genes Are Specifically Involved in the Initiation, Progression, and Lymphatic and Peritoneal Metastasis of Epithelial Ovarian Cancer

Our work aimed to evaluate and differentiate the role of ten lncRNA genes (GAS5, HAND2-AS1, KCNK15-AS1, MAGI2-AS3, MEG3, SEMA3B-AS1, SNHG6, SSTR5-AS1, ZEB1-AS1, and ZNF667-AS1) in the development and progression of epithelial ovarian cancer (EOC). A representative set of clinical samples was used: 140 primary tumors from patients without and with metastases and 59 peritoneal metastases. Using MS-qPCR, we demonstrated an increase in methylation levels of all ten lncRNA genes in tumors compared to normal tissues (p < 0.001). Using RT-qPCR, we showed downregulation and an inverse relationship between methylation and expression levels for ten lncRNAs (rs < -0.5). We further identified lncRNA genes that were specifically hypermethylated in tumors from patients with metastases to lymph nodes (HAND2-AS1), peritoneum (KCNK15-AS1, MEG3, and SEMA3B-AS1), and greater omentum (MEG3, SEMA3B-AS1, and ZNF667-AS1). The same four lncRNA genes involved in peritoneal spread were associated with clinical stage and tumor extent (p < 0.001). Interestingly, we found a reversion from increase to decrease in the hypermethylation level of five metastasis-related lncRNA genes (MEG3, SEMA3B-AS1, SSTR5-AS1, ZEB1-AS1, and ZNF667-AS1) in 59 peritoneal metastases. This reversion may be associated with partial epithelial-mesenchymal transition (EMT) in metastatic cells, as indicated by a decrease in the level of the EMT marker, CDH1 mRNA (p < 0.01). Furthermore, novel mRNA targets and regulated miRNAs were predicted for a number of the studied lncRNAs using the NCBI GEO datasets and analyzed by RT-qPCR and transfection of SKOV3 and OVCAR3 cells. In addition, hypermethylation of SEMA3B-AS1, SSTR5-AS1, and ZNF667-AS1 genes was proposed as a marker for overall survival in patients with EOC.

Prediction Model for Therapeutic Responses in Ovarian Cancer Patients using Paclitaxel-resistant Immune-related lncRNAs

BACKGROUND

Ovarian cancer (OC) is the deadliest malignant tumor in women with a poor prognosis due to drug resistance and lack of prediction tools for therapeutic responses to anti- cancer drugs.

OBJECTIVE

The objective of this study was to launch a prediction model for therapeutic responses in OC patients.

METHODS

The RNA-seq technique was used to identify differentially expressed paclitaxel (PTX)- resistant lncRNAs (DE-lncRNAs). The Cancer Genome Atlas (TCGA)-OV and ImmPort database were used to obtain immune-related lncRNAs (ir-lncRNAs). Univariate, multivariate, and LASSO Cox regression analyses were performed to construct the prediction model. Kaplan- meier plotter, Principal Component Analysis (PCA), nomogram, immune function analysis, and therapeutic response were applied with Genomics of Drug Sensitivity in Cancer (GDSC), CIBERSORT, and TCGA databases. The biological functions were evaluated in the CCLE database and OC cells.

RESULTS

The RNA-seq defined 186 DE-lncRNAs between PTX-resistant A2780-PTX and PTXsensitive A2780 cells. Through the analysis of the TCGA-OV database, 225 ir-lncRNAs were identified. Analyzing 186 DE-lncRNAs and 225 ir-lncRNAs using univariate, multivariate, and LASSO Cox regression analyses, 9 PTX-resistant immune-related lncRNAs (DEir-lncRNAs) acted as biomarkers were discovered as potential biomarkers in the prediction model. Single-cell RNA sequencing (scRNA-seq) data of OC confirmed the relevance of DEir-lncRNAs in immune responsiveness. Patients with a low prediction score had a promising prognosis, whereas patients with a high prediction score were more prone to evade immunotherapy and chemotherapy and had poor prognosis.

CONCLUSION

The novel prediction model with 9 DEir-lncRNAs is a valuable tool for predicting immunotherapeutic and chemotherapeutic responses and prognosis of patients with OC.

Advances in long non-coding RNA regulating drug resistance of cancer

Drug resistance is one of the main challenges in cancer treatment. Long non coding RNAs (lncRNAs) play a complex and precise regulatory role in regulating drug resistance of cancer. The common ways of lncRNA regulating drug resistance of cancer involve ATP binding transporter overexpression, abnormal DNA damage response, tumor cell apoptosis, accumulation of epithelial mesenchymal transformation and cancer stem cell formation. Moreover, studies on exosomal lncRNAs regulating cancer drug resistance are developed in recent years. Further study on the role and mechanism of lncRNAs drug resistance in cancer will help clinical cancer treatment program and explore new treatment methods. This paper reviews recent advances in lncRNAs regulating drug resistance of cancer, especially the role of exosomal lncRNAs.

Identification of lncRNAs Deregulated in Epithelial Ovarian Cancer Based on a Gene Expression Profiling Meta-Analysis

Epithelial ovarian cancer (EOC) is one of the deadliest gynecological cancers worldwide, mainly because of its initially asymptomatic nature and consequently late diagnosis. Long non-coding RNAs (lncRNA) are non-coding transcripts of more than 200 nucleotides, whose deregulation is involved in pathologies such as EOC, and are therefore envisaged as future biomarkers. We present a meta-analysis of available gene expression profiling (microarray and RNA sequencing) studies from EOC patients to identify lncRNA genes with diagnostic and prognostic value. In this meta-analysis, we include 46 independent cohorts, along with available expression profiling data from EOC cell lines. Differential expression analyses were conducted to identify those lncRNAs that are deregulated in (i) EOC versus healthy ovary tissue, (ii) unfavorable versus more favorable prognosis, (iii) metastatic versus primary tumors, (iv) chemoresistant versus chemosensitive EOC, and (v) correlation to specific histological subtypes of EOC. From the results of this meta-analysis, we established a panel of lncRNAs that are highly correlated with EOC. The panel includes several lncRNAs that are already known and even functionally characterized in EOC, but also lncRNAs that have not been previously correlated with this cancer, and which are discussed in relation to their putative role in EOC and their potential use as clinically relevant tools.

A review on the role of ZEB1-AS1 in human disorders

ZEB1 Antisense RNA 1 (ZEB1-AS1) is a type of RNA characterized as long non-coding RNA (lncRNA). This lncRNA has important regulatory roles on its related gene, Zinc Finger E-Box Binding Homeobox 1 (ZEB1). In addition, role of ZEB1-AS1 has been approved in diverse malignancies such as colorectal cancer, breast cancer, glioma, hepatocellular carcinoma and gastric cancer. ZEB1-AS1 serves as a sponge for a number of microRNAs, namely miR-577, miR-335-5p, miR-101, miR-505-3p, miR-455-3p, miR-205, miR-23a, miR-365a-3p, miR-302b, miR-299-3p, miR-133a-3p, miR-200a, miR-200c, miR-342-3p, miR-214, miR-149-3p and miR-1224-5p. In addition to malignant conditions, ZEB1-AS1 has functional role in non-malignant conditions like diabetic nephropathy, diabetic lung, arthrosclerosis, Chlamydia trachomatis infection, pulmonary fibrosis and ischemic stroke. This review outlines different molecular mechanisms of ZEB1-AS1 in a variety of disorders and highlights its importance in their pathogenesis.

Focus on the molecular mechanisms of cisplatin resistance based on multi-omics approaches

Cisplatin is commonly used in combination with other cytotoxic agents as a standard treatment regimen for a variety of solid tumors, such as lung, ovarian, testicular, and head and neck cancers. However, the effectiveness of cisplatin is accompanied by toxic side effects, for instance, nephrotoxicity and neurotoxicity. The response of tumors to cisplatin treatment involves multiple physiological processes, and the efficacy of chemotherapy is limited by the intrinsic and acquired resistance of tumor cells. Although enormous efforts have been made toward molecular mechanisms of cisplatin resistance, the development of omics provides new insights into the understanding of cisplatin resistance at genome, transcriptome, proteome, metabolome and epigenome levels. Mechanism studies using different omics approaches revealed the necessity of multi-omics applications, which provide information at different cellular function levels and expand our recognition of the peculiar genetic and phenotypic heterogeneity of cancer. The present work systematically describes the underlying mechanisms of cisplatin resistance in different tumor types using multi-omics approaches. In addition to the classical mechanisms such as enhanced drug efflux, increased DNA damage repair and changes in the cell cycle and apoptotic pathways, other changes like increased protein damage clearance, increased protein glycosylation, enhanced glycolytic process, dysregulation of the oxidative phosphorylation pathway, ferroptosis suppression and mRNA m6A methylation modification can also induce cisplatin resistance. Therefore, utilizing the integrated omics to identify key signaling pathways, target genes and biomarkers that regulate chemoresistance are essential for the development of new drugs or strategies to restore tumor sensitivity to cisplatin.

Identification of N6-methylandenosine related lncRNA signatures for predicting the prognosis and therapy response in colorectal cancer patients

Despite recent advances in surgical and multimodal therapies, the overall survival (OS) of advanced colorectal cancer (CRC) patients remains low. Thus, discerning sensitive prognostic biomarkers to give the optimistic treatment for CRC patients is extremely critical. N6-methyladenosine (m6A) and long noncoding RNAs (lncRNAs) play an important role in CRC progression. Nonetheless, few studies have focused on the impact of m6A-related lncRNAs on the prognosis, tumor microenvironment (TME) and treatment of CRC. In this study, 1707 m6A-related lncRNAs were identified through Pearson correlation analysis and Weighted co-expression network analysis (WGCNA) using The Cancer Genome Atlas (TCGA) cohort. Then, 28 m6A-related prognostic lncRNAs were screened by univariate Cox regression analysis, followed by identifying two clusters by consensus clustering analysis. A prognostic model consisted of 8 lncRNA signatures was constructed by the least absolute shrinkage and selection operator (LASSO). Kaplan–Meier curve analysis and a nomogram were performed to investigate the prognostic ability of this model. The risk score of prognostic model act as an independent risk factor for OS rate. Functional enrichment analysis indicated that lncRNA signatures related tumor immunity. The low-risk group characterized by increased microsatellite instability-high (MSI-H), mutation burden, and immunity activation, indicated favorable odds of OS. Moreover, the lncRNA signatures were significantly associated with the cancer stem cell (CSC) index and drug sensitivity. In addition, 3 common immune genes shared by the lncRNA signatures were screened out. We found that these immune genes were widely distributed in 2 cell types of TME. Finally, a ceRNA network was constructed to identify ZEB1-AS1 regulatory axis in CRC. We found that ZEB1-AS1 was significantly overexpressed in tumor tissues, and was related to the metastasis of EMT and the chemoresistance of 5-Fu in CRC. Therefore, our study demonstrated the important role of m6A-related lncRNAs in TME remodeling. Moreover, these results illustrated the levels of ZEB1-AS1 might be valuable for predicting the progression and prognosis of CRC, and further provided a new target for the diagnosis and treatment of CRC patients.

TAZ Regulates the Cisplatin Resistance of Epithelial Ovarian Cancer Cells via the ANGPTL4/SOX2 Axis

Objective

Epithelial ovarian cancer (EOC) is a fatal gynecological malignancy. This study explored the mechanism of TAZ in regulating drug sensitivity of cisplatin (DDP-)-resistant EOC cells through the ANGPTL4/SOX2 axis.

Methods

The A2780/DDP cells were prepared by stepwise progressive concentration method. The drug resistance and TAZ expression in EOC cells were determined. Drug sensitivity was measured after TAZ overexpression in A2780 cells and TAZ downregulation in A2780/DDP cells, respectively. The effects of TAZ knockdown on apoptosis rate, stemness, and cancer stem cell (CSC) marker (CD44, OCT4, and ALDH1A) levels in A2780/DDP and DDP-treated A2780/DDP cells were assessed. The binding of TAZ and ANGPTL4 was verified using ChIP-qPCR, and ANGPTL4 and SOX2 levels were determined. The effects of different combined treatments of TAZ, ANGPTL4, and SOX2 on drug sensitivity of A2780/DDP cells and DDP-treated A2780/DDP cells were evaluated.

Results

TAZ was upregulated in drug-resistant EOC cells. TAZ knockdown significantly increased the drug sensitivity of A2780/DDP cells, while TAZ overexpression markedly decreased the drug sensitivity of A2780 cells. TAZ silencing promoted apoptosis of drug-resistant EOC cells and inhibited cell stemness. TAZ targeted ANGPTL4 and TAZ silencing enhanced drug sensitivity of A2780/DDP cells by inhibiting ANGPTL4. ANGPTL4 overexpression elevated SOX2 expression, and SOX2 downregulation reduced the drug resistance and promoted the apoptosis of A2780/DDP cells.

Conclusion

TAZ regulates DDP sensitivity of drug-resistant EOC cells via the ANGPTL4/SOX2 axis.

Long noncoding RNAs as therapeutic targets to overcome chemoresistance in ovarian cancer

Long noncoding RNAs (lncRNAs) have been characterized to play an essential role in ovarian tumorigenesis via controlling a variety of cellular processes, such as cell proliferation, invasion, apoptotic death, metastasis, cell cycle, migration, metabolism, immune evasion, and chemoresistance. The one obstacle for the therapeutic efficacy is due to the development of drug resistance in ovarian cancer patients. Therefore, in this review article, we describe the role of lncRNAs in chemoresistance in ovarian cancer. Moreover, we discuss the molecular mechanism of lncRNAs-involved drug resistance in ovarian cancer. We conclude that lncRNAs could be useful targets to overcome chemoresistance and improve therapeutic outcome in ovarian cancer patients.

Irisin/FNDC5 inhibits the epithelial-mesenchymal transition of epithelial ovarian cancer cells via the PI3K/Akt pathway

PURPOSE

This study explored the role of irisin/fibronectin type III domain-containing protein 5 (FNDC5) in epithelial ovarian cancer and investigated its underlying mechanisms.

METHODS

Immunohistochemistry was performed to analyze the expression of irisin/FNDC5 in epithelial ovarian cancer and normal ovarian tissues. Cell Counting Kit-8, transwell, and wound-healing assays were performed to examine the effect of irisin on the viability, migration, and invasion of ovarian cancer cells, respectively. Western blotting was used to detect the changes of epithelial-mesenchymal transition (EMT)-related proteins and phosphatidylinositol 3-kinase (PI3K)/Akt pathway proteins. Ovarian cancer cells were treated in vitro with the PI3K agonist (740Y-P) in combination with irisin to explore the mechanism of irisin in ovarian cancer.

RESULTS

The expression of irisin/FNDC5 in epithelial ovarian cancer tissue was significantly higher than that in normal ovarian tissues, and the expression in late stage patients with lymph node metastasis was lower than that in early stage patients without metastasis. Irisin inhibited the proliferation, invasion, and migration of epithelial ovarian cancer cells, down-regulated phosphorylated Akt, and inhibited EMT progression. The PI3K agonist, 740Y-P, partially reversed the effects of irisin on the invasion, migration, and EMT of ovarian cancer cells.

CONCLUSION

These findings show that irisin/FNDC5 was highly expressed in ovarian cancer tissues, which may regulate the EMT through the PI3K/Akt signaling pathway and inhibit the proliferation, invasion, and migration of epithelial ovarian cancer.

Keep your eyes peeled for long noncoding RNAs: Explaining their boundless role in cancer metastasis, drug resistance, and clinical application

Cancer metastasis and drug resistance are two major obstacles in the treatment of cancer and therefore, the leading cause of cancer-associated mortalities worldwide. Hence, an in-depth understanding of these processes and identification of the underlying key players could help design a better therapeutic regimen to treat cancer. Earlier thought to be merely transcriptional junk and having passive or secondary function, recent advances in the genomic research have unravelled that long noncoding RNAs (lncRNAs) play pivotal roles in diverse physiological as well as pathological processes including cancer metastasis and drug resistance. LncRNAs can regulate various steps of the complex metastatic cascade such as epithelial-mesenchymal transition (EMT), invasion, migration and metastatic colonization, and also affect the sensitivity of cancer cells to various chemotherapeutic drugs. A substantial body of literature for more than a decade of research evince that lncRNAs can regulate gene expression at different levels such as epigenetic, transcriptional, posttranscriptional, translational and posttranslational levels, depending on their subcellular localization and through their ability to interact with DNA, RNA and proteins. In this review, we mainly focus on how lncRNAs affect cancer metastasis by modulating expression of key metastasis-associated genes at various levels of gene regulation. We also discuss how lncRNAs confer cancer cells either sensitivity or resistance to various chemo-therapeutic drugs via different mechanisms. Finally, we highlight the immense potential of lncRNAs as prognostic and diagnostic biomarkers as well as therapeutic targets in cancer.

The role of CCR2 in prognosis of patients with endometrial cancer and tumor microenvironment remodeling

Tumor microenvironment (TME) plays a core role in the genesis and progress of endometrial carcinoma (EC). The immune system, a crucial element of TME, functions in various immune cells. In this paper, we have tried to evaluate the prognosis in EC patients by the status of TME. The ESTIMATE algorithm was implemented to computer the number of immune and stromal components in EC tissues from the Cancer Genome Atlas dataset. The CIBERSORT algorithm was employed to assess the proportion of tumor-infiltrating immune cells in EC tissues, which were quantified as Stromal score and Immune score. After the construction of protein–protein interaction network, cell–cell chemokine receptor 2 (CCR2) was identified as a potential predictive element for EC. Further analysis indicated that a higher expression of CCR2 in EC patients was correlated with a better prognosis and a prolonged disease-free survival. According to the transcript level of CCR2, samples were separated into low- and high-expression groups. Gene Set Enrichment Analysis unveiled that metabolism-related pathways were mostly abundant in groups with high-expression, the other one was primarily correlated to immune-related activities. We figured out that some immune cells were positively related to CCR2, suggesting that CCR2 might serve as the immune-dominant status of TME, which was verified by qRT-PCR and HPA analysis in transcriptome and protein level, respectively. Also, CCR2 showed high correlation with immune modulators and chemokine signaling pathway. Thus, the level of CCR2 might have a prognostic value for EC patients, which provides a novel insight for therapeutic strategies of EC.

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.