Novel role of lncRNA CHRF in cisplatin resistance of ovarian cancer is mediated by miR-10b induced EMT and STAT3 signaling

Salidroside overcomes cisplatin resistance in ovarian cancer via the inhibition of CRNDE-mediated autophagy

Cisplatin (DDP) resistance significantly affects the survival rate of patients with ovarian cancer (OC). Autophagy is recognized as a common cause of resistance to DDP. This study aimed to investigate the impact of salidroside on OC progression and explore its potential regulatory effects on DDP resistance and autophagy. A DDP-resistant A2780 (A2780/DDP) cell line was induced by exposure to increasing DDP concentrations. The protein levels of autophagy proteins (p62, Beclin-1, ATG5, and LC3 II/LC3 I), apoptosis proteins (cleaved caspase-3 and cleaved caspase-9), and PI3K/AKT/mTOR pathway were determined by western blotting. Autophagic vacuoles in cells were observed with LC3 dyeing with confocal fluorescent microscopy. Cell viability and apoptosis were evaluated by cell counting kit-8 assays and flow cytometry. RT-qPCR was conducted to measure the relative levels of various lncRNAs in A2780 or A2780/DDP cells. A xenograft model was established by subcutaneous injection of 1 × 107 A2780 cells into the posterior flank of nude mice. Tumor size and weight were recorded. The expression of Ki67, cleaved caspase-3 and LC3 in tumor tissues was assessed by immunohistochemistry staining. The biodistribution of DDP in organs and blood of normal nude mice and tumors of tumor-bearing mice was detected using the ICP-MS. Hematoxylin-eosin staining was used to assess the histopathological changes of kidney, liver, and spleen sections. For in vitro analysis, autophagy was enhanced in DDP-resistant A2780 cells. Additionally, salidroside inhibits DDP resistance to A2780 cells via autophagy inhibition. Mechanistically, salidroside downregulated CRNDE in DDP-resistant A2780 cells. CRNDE knockdown inhibited autophagy, while CRNDE overexpression reversed the protective effects of salidroside. Additionally, salidroside activated the PI3K/AKT/mTOR pathway in DDP-resistant A2780 cells, and inhibition of PI3K reversed the effect of salidroside on inhibiting autophagy and apoptosis of A2780/DDP cells. For in vivo analysis, salidroside inhibited tumor growth, autophagy, and nephrotoxicity of DDP. Additionally, salidroside downregulated CRNDE and activated PI3K/AKT/mTOR signaling in vivo. Salidroside prevents autophagy-mediated DDP resistance in OC by downregulating lncRNA CRNDE and activating the PI3K/AKT/mTOR pathway.

Unveiling the Role of JAK2/STAT3 signaling in chemoresistance of gynecological cancers: From mechanisms to therapeutic implications

Gynecological cancers, encompassing ovarian, cervical, endometrial, vulvar, and vaginal cancers, present a significant global health burden due to high incidence rates and associated mortality. Among these, ovarian, cervical, and endometrial cancers are particularly challenging, characterized by late-stage diagnoses, distinct pathological features, and significant resistance to chemotherapy. A major contributor to treatment failure is chemoresistance, driven by multifactorial mechanisms such as dysregulation of apoptosis, DNA repair, metabolic reprogramming, and the tumor microenvironment. The Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway plays a pivotal role in promoting chemoresistance, enhancing tumor cell survival, stemness, and immune evasion through the transcriptional regulation of anti-apoptotic and multidrug resistance genes. Persistent activation of this pathway not only sustains tumor progression but also limits the efficacy of standard chemotherapeutics, such as paclitaxel, cisplatin, and platinum-based agents. This review comprehensively examines the molecular mechanisms underlying JAK2/STAT3-mediated chemoresistance in gynecological cancers, highlighting its interactions with critical regulatory networks, including non-coding RNAs, cytokine signaling, hypoxia, and extracellular vesicles. We further explore therapeutic interventions targeting the JAK2/STAT3 axis, encompassing small molecule inhibitors, monoclonal antibodies, nanoparticles, and oncolytic viruses. Natural products and synthetic compounds targeting this pathway demonstrate significant potential in overcoming resistance and improving chemotherapy response. The findings underscore the critical role of JAK2/STAT3 signaling in the persistence and progression of chemoresistant gynecological cancers and advocate for the integration of pathway-targeted therapies into current treatment paradigms. By disrupting this axis, emerging therapies offer a promising strategy to enhance drug sensitivity and improve patient outcomes, paving the way for more effective and personalized approaches in gynecological oncology.

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.

Dual Roles of miR-10a-5p and miR-10b-5p as Tumor Suppressors and Oncogenes in Diverse Cancers

Cancer is a complex genetic disorder characterized by abnormalities in both coding and regulatory non-coding RNAs. microRNAs (miRNAs) are key regulatory non-coding RNAs that modulate cancer development, functioning as both tumor suppressors and oncogenes. miRNAs play critical roles in cancer progression, influencing key processes such as initiation, promotion, and metastasis. They exert their effects by targeting tumor suppressor genes, thereby facilitating cancer progression, while also inhibiting oncogenes to prevent further disease advancement. The miR-10 family, particularly miR-10a-5p and miR-10b-5p (miR-10a/b-5p), is notably involved in cancer progression. Intriguingly, their functions can differ across different cancers, sometimes promoting and at other times suppressing tumor growth depending on the cancer type and target genes. This review explores the dual roles of miR-10a/b-5p as tumor-suppressive miRNAs (TSmiRs) or oncogenic miRNAs (oncomiRs) in various cancers by examining their molecular and cellular mechanisms and their impact on the tumor microenvironment. Furthermore, we discuss the potential of miR-10a/b-5p as therapeutic targets, emphasizing miRNA-based strategies for cancer treatment. The insights discussed in this review aim to advance our understanding of miR-10a/b-5p's roles in tumor biology and their application in developing innovative cancer therapies.

Drug resistance biomarkers in ovarian cancer: a bibliometric study from 2017 to 2022

Background

Late diagnosis and patient relapse, mainly due to chemoresistance, are the key reasons for the high mortality rate of ovarian cancer patients. Hence, the search for biomarkers of high predictive value within the phenomenon of chemoresistance is vital. This study performs a bibliometric analysis of the scientific literature concerning biomarkers of drug resistance in ovarian cancer, considering the period from 2017 to 2022.

Methods

The terms "drug resistance biomarker" and "ovarian cancer" were linked by the Boolean operator "AND". The search was done in PubMed, selecting documents published over the last 5 years (2017-2022), which were analyzed with the open-source tool Bibliometrix developed in the R package. The language of the publications was restricted to English. Several types of papers such as case reports, clinical trials, comparative studies, and original articles were considered.

Results

A total of 335 scientific articles were analyzed. The United States and China were the leading contributors and established the largest number of scientific collaborations. The Huazhong University of Science and Technology and the University of Texas MD Anderson Cancer Center were the most influential institutions. The Journal of Ovarian Research, International Journal of Molecular Science, and Scientific Reports are among the most relevant journals. The study identified high-profile, relevant thematic niches and important descriptors that indicate topics of interest, including studies on women, cell lines, solid tumors, and gene expression regulation. As well as studies involving middle-aged and adult participants, and those focusing on prognosis evaluation. Descriptors such as "drug resistance," "neoplasm," "genetics," "biomarker," "gene expression profile," and "drug therapy" would indicate new research trends. In addition, we propose that BCL-2, CHRF, SNAIL, miR-363, iASPP, ALDH1, Fzd7, and EZH2 are potential biomarkers of drug resistance.

Conclusions

This paper contributes to the global analysis of the scientific investigation related to drug resistance biomarkers in ovarian cancer to facilitate further studies and collaborative networks, which may lead to future improvements in therapy for this lethal disease.

Drug resistance in human cancers - Mechanisms and implications

Cancers have complex etiology and pose a significant impact from the health care perspective apart from the socio-economic implications. The enormity of challenge posed by cancers can be understood from the fact that clinical trials for cancer therapy has yielded minimum potential promises compared to those obtained for other diseases. Surgery, chemotherapy and radiotherapy continue to be the mainstay therapeutic options for cancers. Among the challenges posed by these options, induced resistance to chemotherapeutic drugs is probably the most significant contributor for poor prognosis and ineffectiveness of the therapy. Drug resistance is a property exhibited by almost all cancer types including carcinomas, leukemias, myelomas, sarcomas and lymphomas. The mechanisms by which drug resistance is induced include the factors within the tumor microenvironment, mutations in the genes responsible for drug metabolism, changes in the surface drug receptors and increased drug efflux. We present here comprehensively the drug resistance in cancers along with their mechanisms. Also, apart from resistance to regularly used chemotherapeutic drugs, we present resistance induction to new generation therapeutic agents such as monoclonal antibodies. Finally, we have discussed the experimental approaches to understand the mechanisms underlying induction of drug resistance and potential ways to mitigate induced drug resistance.

PRR34-AS1 promotes mitochondrial division and glycolytic reprogramming in hepatocellular carcinoma cells through upregulation of MIEF2

LncRNA PRR34-AS1 overexpression promotes the proliferation and invasion of hepatocellular carcinoma (HCC) cells, but whether it affects HCC energy metabolism remains unclear. Mitochondrial division and glycolytic reprogramming play important roles in tumor development. In this study, the differential expression of PRR34-AS1 is explored via TCGA analysis, and higher levels of PRR34-AS1 are detected in patients with liver cancer than in healthy individuals. A series of experiments, such as CCK-8, PCR, and immunofluorescence staining, reveal that the proliferation, invasion, glycolysis, and mitochondrial division of PRR34-AS1-overexpressing hepatoma cells are significantly promoted. TCGA analysis and immunohistochemistry reveal high expression of the mitochondrial dynamin MIEF2 in liver cancer tissues. Dual-luciferase reporter assays confirm that miR-498 targets and binds to mitochondrial elongation factor 2 (MIEF2). In addition, we show that PRR34-AS1 can sponge miR-498. Therefore, we further investigate the effects of the lncRNA PRR34-AS1/miR-498/MIEF2 axis on the growth, glucose metabolism, and mitochondrial division in hepatocellular carcinoma cells. A series of experiments are performed on hepatocellular carcinoma cells after different treatments. The results show that the proliferative activity, invasive ability, and glycolytic level of hepatocellular carcinoma cells are decreased in HCC cells with low PRR34-AS1 expression, and the miR-498 expression level is increased in these cells. Inhibition of miR-498 or overexpression of MIEF2 restored the proliferative activity, invasive ability, glycolysis, and mitochondrial division in hepatocellular carcinoma cells. Thus, PRR34-AS1 regulates MIEF2 by sponging miR-498, thereby promoting mitochondrial division, mediating glycolytic reprogramming and ultimately driving the growth and invasion of HCC cells. Furthermore, in vivo mouse experiments yield results similar to those of the in vitro experiments, verifying the above results.

Proto-oncogene c-Myb potentiates cisplatin resistance of ovarian cancer cells by downregulating lncRNA NKILA and modulating cancer stemness and LIN28A-let7 axis

Ovarian cancer is a major gynecological cancer that has poor prognosis associated mainly to its late diagnosis. Cisplatin is an FDA approved ovarian cancer therapy and even though the therapy is initially promising, the patients mostly progress to resistance against cisplatin. The underlying mechanisms are complex and not very clearly understood. Using two different paired cell lines representing cisplatin-sensitive and the cisplatin-resistant ovarian cancer cells, the ES2 and the A2780 parental and cisplatin-resistant cells, we show an elevated proto-oncogene c-Myb in resistant cells. We further show down-regulated lncRNA NKILA in resistant cells with its de-repression in resistant cells when c-Myb is silenced. NKILA negatively correlates with cancer cell and invasion but has no effect on cellular proliferation or cell cycle. C-Myb activates NF-κB signaling which is inhibited by NKILA. The cisplatin resistant cells are also marked by upregulated stem cell markers, particularly LIN28A and OCT4, and downregulated LIN28A-targeted let-7 family miRNAs. Whereas LIN28A and downregulated let-7s individually de-repress c-Myb-mediated cisplatin resistance, the ectopic expression of let-7s attenuates LIN28A effects, thus underlying a c-Myb-NKILA-LIN28A-let-7 axis in cisplatin resistance of ovarian cancer cells that needs to be further explored for therapeutic intervention.

Role of STAT3 in cancer cell epithelial‑mesenchymal transition (Review)

Since its discovery, the role of the transcription factor, signal transducer and activator of transcription 3 (STAT3), in both normal physiology and the pathology of numerous diseases, including cancer, has been extensively studied. STAT3 is aberrantly activated in different types of cancer, fulfilling a critical role in cancer progression. The biological process, epithelial‑mesenchymal transition (EMT), is indispensable for embryonic morphogenesis. During the development of cancer, EMT is hijacked to confer motility, tumor cell stemness, drug resistance and adaptation to changes in the microenvironment. The aim of the present review was to outline recent advances in knowledge of the role of STAT3 in EMT, which may contribute to the understanding of the function of STAT3 in EMT in various types of cancer. Delineating the underlying mechanisms associated with the STAT3‑EMT signaling axis may generate novel diagnostic and therapeutic options for cancer treatment.

Novel players in the development of chemoresistance in ovarian cancer: ovarian cancer stem cells, non-coding RNA and nuclear receptors

Ovarian cancer (OC) ranks as the fifth leading factor for female mortality globally, with a substantial burden of new cases and mortality recorded annually. Survival rates vary significantly based on the stage of diagnosis, with advanced stages posing significant challenges to treatment. OC is primarily categorized as epithelial, constituting approximately 90% of cases, and correct staging is essential for tailored treatment. The debulking followed by chemotherapy is the prevailing treatment, involving platinum-based drugs in combination with taxanes. However, the efficacy of chemotherapy is hindered by the development of chemoresistance, both acquired during treatment (acquired chemoresistance) and intrinsic to the patient (intrinsic chemoresistance). The emergence of chemoresistance leads to increased mortality rates, with many advanced patients experiencing disease relapse shortly after initial treatment. This review delves into the multifactorial nature of chemoresistance in OC, addressing mechanisms involving transport systems, apoptosis, DNA repair, and ovarian cancer stem cells (OCSCs). While previous research has identified genes associated with these mechanisms, the regulatory roles of non-coding RNA (ncRNA) and nuclear receptors in modulating gene expression to confer chemoresistance have remained poorly understood and underexplored. This comprehensive review aims to shed light on the genes linked to different chemoresistance mechanisms in OC and their intricate regulation by ncRNA and nuclear receptors. Specifically, we examine how these molecular players influence the chemoresistance mechanism. By exploring the interplay between these factors and gene expression regulation, this review seeks to provide a comprehensive mechanism driving chemoresistance in OC.

MicroRNAs, long non-coding RNAs, and circular RNAs and gynecological cancers: focus on metastasis

Gynecologic cancer is a significant cause of death in women worldwide, with cervical cancer, ovarian cancer, and endometrial cancer being among the most well-known types. The initiation and progression of gynecologic cancers involve a variety of biological functions, including angiogenesis and metastasis-given that death mostly occurs from metastatic tumors that have invaded the surrounding tissues. Therefore, understanding the molecular pathways underlying gynecologic cancer metastasis is critical for enhancing patient survival and outcomes. Recent research has revealed the contribution of numerous non-coding RNAs (ncRNAs) to metastasis and invasion of gynecologic cancer by affecting specific cellular pathways. This review focuses on three types of gynecologic cancer (ovarian, endometrial, and cervical) and three kinds of ncRNAs (long non-coding RNAs, microRNAs, and circular RNAs). We summarize the detailed role of non-coding RNAs in the different pathways and molecular interactions involved in the invasion and metastasis of these cancers.

Chemotherapy-induced metastasis: molecular mechanisms and clinical therapies

Chemotherapy, the most widely accepted treatment for malignant tumors, is dependent on cell death induced by various drugs including antimetabolites, alkylating agents, mitotic spindle inhibitors, antitumor antibiotics, and hormonal anticancer drugs. In addition to causing side effects due to non-selective cytotoxicity, chemotherapeutic drugs can initiate and promote metastasis, which greatly reduces their clinical efficacy. The knowledge of how they induce metastasis is essential for developing strategies that improve the outcomes of chemotherapy. Herein, we summarize the recent findings on chemotherapy-induced metastasis and discuss the underlying mechanisms including tumor-initiating cell expansion, the epithelial-mesenchymal transition, extracellular vesicle involvement, and tumor microenvironment alterations. In addition, the use of combination treatments to overcome chemotherapy-induced metastasis is also elaborated.

The Role of EMT-Related lncRNAs in Ovarian Cancer

Ovarian cancer (OC) is one of the deadliest cancers worldwide; late diagnosis and drug resistance are two major factors often responsible for high morbidity and treatment failure. Epithelial-to-mesenchymal transition (EMT) is a dynamic process that has been closely linked with cancer. Long non-coding RNAs (lncRNAs) have been also associated with several cancer-related mechanisms, including EMT. We conducted a literature search in the PubMed database in order to sum up and discuss the role of lncRNAs in regulating OC-related EMT and their underlying mechanisms. Seventy (70) original research articles were identified, as of 23 April 2023. Our review concluded that the dysregulation of lncRNAs is highly associated with EMT-mediated OC progression. A comprehensive understanding of lncRNAs' mechanisms in OC will help in identifying novel and sensitive biomarkers and therapeutic targets for this malignancy.

Overcoming Acquired Drug Resistance to Cancer Therapies through Targeted STAT3 Inhibition

Anti-neoplastic agents for cancer treatment utilize many different mechanisms of action and, when combined, can result in potent inhibition of cancer growth. Combination therapies can result in long-term, durable remission or even cure; however, too many times, these anti-neoplastic agents lose their efficacy due to the development of acquired drug resistance (ADR). In this review, we evaluate the scientific and medical literature that elucidate STAT3-mediated mechanisms of resistance to cancer therapeutics. Herein, we have found that at least 24 different anti-neoplastic agents-standard toxic chemotherapeutic agents, targeted kinase inhibitors, anti-hormonal agents, and monoclonal antibodies-that utilize the STAT3 signaling pathway as one mechanism of developing therapeutic resistance. Targeting STAT3, in combination with existing anti-neoplastic agents, may prove to be a successful therapeutic strategy to either prevent or even overcome ADR to standard and novel cancer therapies.

Advances in targeting of miR‑10‑associated lncRNAs/circRNAs for the management of cancer (Review)

With advancements in sequencing technologies, an increasing number of aberrantly expressed long-non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) have been identified in various types of cancer. lncRNAs and circRNAs are now well-established tumor-influencing factors in cancer, driving not only tumor proliferation and invasion, but also cancer progression, drug resistance and metastatic recurrence. The majority of lncRNAs and circRNAs influence cancer progression by targeting microRNAs (miRNAs/miRs). miR-10a and miR-10b, key members of the miR-10 family, have been shown to play important regulatory roles in cell proliferation, differentiation to cancer progression, and development. Manual evaluation and grouping according to different types of competing endogenous RNA and tumor was performed. The review outlined the current state of knowledge on the regulation of miR-10 family-related lncRNAs and circRNAs. The involvement of lncRNAs and circRNAs in the biogenesis, maturation and function of malignant tumors through the miR-10 family, and the key gene targets and signaling cascades that lncRNAs and circRNAs regulate through the miR-10 family were summarized. Based on the findings of this review, it can be hypothesized that lncRNAs and circRNAs targeting the miR-10 family may serve as diagnostic/prognostic markers and/or therapeutic targets for the management of cancer.

Recent Updates on the Role of the MicroRNA-10 Family in Gynecological Malignancies

The ever-increasing morbidity associated with gynecological malignancies constantly endangers the physical and psychological health of women. Since a long time, there has been an urgent need for a deeper understanding of the tumorigenesis and the development of gynecological cancer to identify new molecular markers for early diagnosis and metastatic disease prognosis and for the development of therapeutic targets. MicroRNAs are crucial cellular regulators. The microRNA-10 (miR-10) family has been found to play an integral role in the evolution of numerous cancer types. A comprehensive understanding of current studies on miR-10 could provide better insights into future research and clinical applications in related fields. This article reviews the latest research on the role of the miR-10 family in gynecological malignancies and the relevant molecular mechanism, mainly focusing on endometrial, cervical, and ovarian cancers.

miR-125b-5p upregulation by TRIM28 induces cisplatin resistance in non-small cell lung cancer through CREB1 inhibition

OBJECTIVE

miR-125b-5p plays an important role in the development of cancer and drug resistance. However, in cisplatin resistance of non-small cell lung cancer (NSCLC), the function and potential mechanism of miR-125b-5p is still unclear. The aim of this study was to investigate the role and molecular mechanism of miR-125b-5p in cisplatin resistance of NSCLC.

METHODS

A GEO dataset (GSE168707) was analyzed to find high miR-125b-5p levels were associated with DDP resistance. miR-125b-5p expression levels were detected in A549 and A549/DDP cells via real-time quantitative RT-PCR (qRT-PCR). Luciferase reporter assays, western blots and mouse model xenografted were performed to identify CREB1 as a direct target gene of miR-125b-5p. Cell proliferation and apoptosis were also performed to identify whether miR-125b-5p upregulation by TRIM28 induces DDP resistance in NSCLC through CREB1 inhibition.

RESULTS

In A549/DDP cells, miR-125b-5p expression was upregulated compared to A549 cells. Then miR-125b-5p was found to increase DDP resistance in NSCLC in vivo and in vitro by increasing cell proliferation and suppressing cell apoptosis. Bioinformatic analyses were used to search for gene which miR-125b-5p can target. We identified miR-125b-5p can regulate CREB1 via luciferase reporter assays, qRT-PCR and western blots. Cell proliferation and apoptosis were also performed to confirm miR-125b-5p could impact on CREB1 and induce the DDP resistance in NSCLC. Additionally, we used bioinformatic analyses to find tripartite motif-containing 28 (TRIM28) as a transcriptional enhance factor of miR-125b-5p. The expression of TRIM28 was upregulated in A549/DDP cells compared with that in A549 cells by qRT-PCR. Finally, we found TRIM28 could mediate DDP resistance through miR-125b-5p/CREB1 axis via cell proliferation, western blot and apoptosis assay.

CONCLUSIONS

Overall, our findings demonstrated novel functions and mechanisms underlying DDP resistance in NSCLC through the TRIM28/miR-125b-5p/CREB1 axis. These may serve as novel therapeutic targets to improve the treatment efficacy using DDP for NSCLC in the future.

Non-coding RNA in cancer drug resistance: Underlying mechanisms and clinical applications

Cancer is one of the most frequently diagnosed malignant diseases worldwide, posing a serious, long-term threat to patients’ health and life. Systemic chemotherapy remains the first-line therapeutic approach for recurrent or metastatic cancer patients after surgery, with the potential to effectively extend patient survival. However, the development of drug resistance seriously limits the clinical efficiency of chemotherapy and ultimately results in treatment failure and patient death. A large number of studies have shown that non-coding RNAs (ncRNAs), particularly microRNAs, long non-coding RNAs, and circular RNAs, are widely involved in the regulation of cancer drug resistance. Their dysregulation contributes to the development of cancer drug resistance by modulating the expression of specific target genes involved in cellular apoptosis, autophagy, drug efflux, epithelial-to-mesenchymal transition (EMT), and cancer stem cells (CSCs). Moreover, some ncRNAs also possess great potential as efficient, specific biomarkers in diagnosis and prognosis as well as therapeutic targets in cancer patients. In this review, we summarize the recent findings on the emerging role and underlying mechanisms of ncRNAs involved in cancer drug resistance and focus on their clinical applications as biomarkers and therapeutic targets in cancer treatment. This information will be of great benefit to early diagnosis and prognostic assessments of cancer as well as the development of ncRNA-based therapeutic strategies for cancer patients.

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.

STAT3-EMT axis in tumors: Modulation of cancer metastasis, stemness and therapy response

Epithelial-to-mesenchymal transition (EMT) mechanism is responsible for metastasis of tumor cells and their spread to various organs and tissues of body, providing undesirable prognosis. In addition to migration, EMT increases stemness and mediates therapy resistance. Hence, pathways involved in EMT regulation should be highlighted. STAT3 is an oncogenic pathway that can elevate growth rate and migratory ability of cancer cells and induce drug resistance. The inhibition of STAT3 signaling impairs cancer progression and promotes chemotherapy-mediated cell death. Present review focuses on STAT3 and EMT interaction in modulating cancer migration. First of all, STAT3 is an upstream mediator of EMT and is able to induce EMT-mediated metastasis in brain tumors, thoracic cancers and gastrointestinal cancers. Therefore, STAT3 inhibition significantly suppresses cancer metastasis and improves prognosis of patients. EMT regulators such as ZEB1/2 proteins, TGF-β, Twist, Snail and Slug are affected by STAT3 signaling to stimulate cancer migration and invasion. Different molecular pathways such as miRNAs, lncRNAs and circRNAs modulate STAT3/EMT axis. Furthermore, we discuss how STAT3 and EMT interaction affects therapy response of cancer cells. Finally, we demonstrate targeting STAT3/EMT axis by anti-tumor agents and clinical application of this axis for improving patient prognosis.

Ovarian cancer in Lebanese women: a 12-year comparative epidemiological study and trend analysis

Purpose

Over the last decade, Lebanon has experienced an increase in the rate of cancer patients. The aim of this study is to investigate the incidence rates of ovarian cancer in Lebanese women over a period of 12 years and to compare them to other countries.

Methods

Data were collected from the Lebanese National Cancer Registry for the time period 2005-2016 (inclusive). Data from other countries were retrieved from an online database 'Cancer Incidence in Five Continents'. The age-specific and age-standardised incidence rates (ASIR) were calculated and analysed using Joinpoint regression.

Results

Ovarian cancer ranked seventh among the commonest cancers in Lebanese women in the studied time frame. Approximately 189 new cases were reported every year, with an average age-standardised incidence rate of 7.88 (per 100,000 women). Ovarian cancer showed a significantly decreasing trend in the 12 years of study. Lebanon had one of the highest ASIR for ovarian cancer among regional countries and randomly selected countries.

Conclusion

Lebanon presented a high ASIR for ovarian cancer compared to regional countries, and was placed among the top ASIRs compared to countries worldwide. However, with the decreasing ovarian cancer trends, it is important to implement efficacious awareness in order to detect all OC cases.

Impact of salvage cytotoxic chemotherapy on prognosis in patients with recurrence after radical cystectomy: a multi-institutional retrospective study

Background

In patients experiencing disease recurrence after radical cystectomy (RC) for bladder cancer, data about the impact of clinicopathologic factors, including salvage treatment using cytotoxic chemotherapy, on the survival are scarce. We investigated the prognostic value of clinicopathologic factors and the treatment effect of salvage cytotoxic chemotherapy (SC) in such patients.

Methods

In this retrospective study, we evaluated the clinical data for 86 patients who experienced recurrence after RC. Administration of SC or of best supportive care (BSC) was determined in consultation with the urologist in charge and in accordance with each patient’s performance status, wishes for treatment, and renal function. Statistical analyses explored for prognostic factors and evaluated the treatment effect of SC compared with BSC in terms of cancer-specific survival (CSS).

Results

Multivariate analyses showed that liver metastasis after RC (hazard ratio [HR] 2.13; 95% confidence interval [CI] 1.17 to 3.85; P = 0.01) and locally advanced disease at RC (HR 1.92; 95% CI 1.06 to 3.46; P = 0.03) are independent risk factors for worse CSS in patients experiencing recurrence after RC. In a risk stratification model, patients were assigned to one of two groups based on liver metastasis and locally advanced stage. In the high-risk group, which included 68 patients with 1–2 risk factors, CSS was significantly better for patients receiving SC than for those receiving BSC (median survival duration: 9.4 months vs. 2.4 months, P = 0.005). The therapeutic effect of SC was not related to a history of adjuvant chemotherapy.

Conclusions

The present study indicated the potential value of 1st-line SC in patients experiencing recurrence after RC even with advanced features, such as liver metastasis after RC and locally advanced disease at RC.

Noncoding RNAs and their therapeutics in paclitaxel chemotherapy: Mechanisms of initiation, progression, and drug sensitivity

The identification of agents that can reverse drug resistance in cancer chemotherapy, and enhance the overall efficacy is of great interest. Paclitaxel (PTX) belongs to taxane family that exerts an antitumor effect by stabilizing microtubules and inhibiting cell cycle progression. However, PTX resistance often develops in tumors due to the overexpression of drug transporters and tumor-promoting pathways. Noncoding RNAs (ncRNAs) are modulators of many processes in cancer cells, such as apoptosis, migration, differentiation, and angiogenesis. In the present study, we summarize the effects of ncRNAs on PTX chemotherapy. MicroRNAs (miRNAs) can have opposite effects on PTX resistance (stimulation or inhibition) via influencing YES1, SK2, MRP1, and STAT3. Moreover, miRNAs modulate the growth and migration rates of tumor cells in regulating PTX efficacy. PIWI-interacting RNAs, small interfering RNAs, and short-hairpin RNAs are other members of ncRNAs regulating PTX sensitivity of cancer cells. Long noncoding RNAs (LncRNAs) are similar to miRNAs and can modulate PTX resistance/sensitivity by their influence on miRNAs and drug efflux transport. The cytotoxicity of PTX against tumor cells can also be affected by circular RNAs (circRNAs) and limitation is that oncogenic circRNAs have been emphasized and experiments should also focus on onco-suppressor circRNAs.

HOTTIP Mediated Therapy Resistance in Glioma Cells Involves Regulation of EMT-Related miR-10b

The advanced grade glioblastomas are characterized by dismal five-year survival rates and are associated with worse outcomes. Additionally, resistance to therapies is an additional burden responsible for glioma associated mortality. We studied the resistance against temozolomide (TMZ) as a surrogate to understand the mechanism of therapy resistance in glioma cancer cells. Screening of three glioma cells lines, A172, LN229 and SF268 revealed that SF268 glioma cells were particularly resistant to TMZ with the IC-50 of this cell line for TMZ ten times higher than for the other two cell lines. A role of lncRNAs in glioma progression has been identified in recent years and, therefore, we focused on lncRNAs for their role in regulating TMZ resistance in glioma cancer cells. lncRNA HOTTIP was found to be particularly elevated in SF268 cells and over-expression of HOTTIP in both A172 and LN229 remarkably increased their TMZ IC-50s, along with increased cell proliferation, migration, clonogenicity and markers of angiogenesis and metastasis. As a mechanism we observed increased expression of miRNA-10b and mesenchymal markers Zeb1/Zeb2 and reduced expression of E-cadherin in SF268 cells indicating a role of EMT in TMZ resistance. A172 and LN229 cells with overexpressed HOTTIP also had similarly induced EMT and the elevated miR-10b levels. Further, silencing of miR-10b in HOTTIP overexpressing cells as well as the SF268 cells reversed EMT with associated sensitization of all the tested cells to TMZ. Our results thus present a case for HOTTIP in native as well as acquired resistance of glioma cells against chemotherapy, with a key mechanistic role of EMT and the miR-10b. Thus, HOTTIP as well as miR-10b are critical targets for glioma therapy, and need to be tested further.

Non-Coding Transcriptome Provides Novel Insights into the Escherichia coli F17 Susceptibility of Sheep Lamb

It has long been recognized that enterotoxigenic Escherichia coli (ETEC) is the major pathogen responsible for vomiting and diarrhea. E. coli F17, a main subtype of ETEC, is characterized by high morbidity and mortality in young livestock. However, the transcriptomic basis underlying E. coli F17 infection has not been fully understood. In this study, RNA sequencing was performed to explore the expression profiles of circRNAs and miRNAs in the jejunum of E. coli F17-antagonism (AN) and -sensitive (SE) lambs. A total of 16,534 circRNAs and 271 miRNAs (125 novel miRNAs and 146 annotated miRNAs) were screened, and 214 differentially expressed (DE) circRNAs and 53 DE miRNAs were detected between the AN and SE lambs (i.e., novel_circ_0025840, novel_circ_0022779, novel_miR_107, miR-10b). Functional enrichment analyses showed that source genes of DE circRNAs were mainly involved in metabolic-related pathways, while target genes of DE miRNAs were mainly enriched in the immune response pathways. Then, a two-step machine learning approach combining Random Forest (RF) and XGBoost (candidates were first selected by RF and further assessed by XGBoost) was performed, which identified 44 circRNAs and 39 miRNAs as potential biomarkers (i.e., novel_circ_0000180, novel_circ_0000365, novel_miR_192, oar-miR-496-3p) for E. coli infection. Furthermore, circRNA-related and lncRNA-related ceRNA networks were constructed, containing 46 circRNA-miRNA-mRNA competing triplets and 630 lncRNA-miRNA-mRNA competing triplets, respectively. By conducting a serious of bioinformatic analyses, our results revealed important circRNAs and miRNAs that could be potentially developed as candidate biomarkers for intestinal inflammatory response against E. coli F17 infection; our study can provide novel insights into the underlying mechanisms of intestinal immunity.

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

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

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.

The emerging role of miR-10 family in gastric cancer

Evidence has demonstrated that miRNAs play an irreplaceable role in tumorigenesis and progression of a broad range of cancers, including gastric cancer. Among these miRNAs, miR-10a and miR-10b have been identified to critically participate in gastric carcinogenesis and malignant progression. In this review, we briefly describe the role of miR-10a and miR-10b in gastric cancer, especially in the regulation of cell proliferation, apoptosis, cell cycle, migration, invasion and metastasis, drug resistance, and cancer stem cells. Furthermore, we highlight several compounds that target the miR-10 family and exhibit antitumor activity in cancer cells. Moreover, we conclude that targeting the miR-10 family might be a promising approach for the treatment of gastric cancer.

miR-526b-3p inhibits lung cancer cisplatin-resistance and metastasis by inhibiting STAT3-promoted PD-L1

Chemotherapy remains the primary treatment of advanced solid cancer, including lung cancer. However, as first-line treatment, cisplatin-based therapy is restricted by the frequent development of drug resistance. Increasing data showed that the programmed cell death protein ligand 1 (PD-L1) plays a vital role in regulating cisplatin resistance. However, the underlying mechanisms are not fully understood. We found that miR-526b-3p expression declined while PD-L1 was elevated in cisplatin-resistant lung cancer compared to that in cisplatin-sensitive lung cancer by analyzing clinical samples. Significantly, miR-526b-3p was associated with response to cisplatin negatively. We further demonstrated that miR-526b-3p reversed cisplatin resistance, suppressed metastasis, and activated CD8+ T cells in a STAT3/PD-L1-dependent manner. Thus, our findings extended the knowledge of PD-L1-mediated cisplatin resistance of lung cancer. In addition, the introduction of miR-526b-3p provided a new clue to improve the anti-tumor effects of the combination of immunotherapy and chemotherapy.

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.

Long noncoding RNA HULC contributes to paclitaxel resistance in ovarian cancer via miR-137/ITGB8 axis

Long noncoding RNA (lncRNA) highly upregulated in liver cancer (HULC) has been reported to be implicated in chemoresistance. However, the potential mechanism of HULC in paclitaxel (PTX)-resistant ovarian cancer (OC) remains undefined. The expression of RNAs and proteins was measured by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) and Western blot assay. The PTX resistance and apoptotic rate were assessed via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry, respectively. Furthermore, the interaction between miR-137 and HULC or integrin beta-8 (ITGB8) was predicted by miRcode and starBase v2.0 and then verified by dual luciferase reporter and RNA pull-down assays. In addition, the xenograft mice model was established to explore the effects of HULC in vivo. HULC was significantly upregulated and miR-137 was downregulated in PTX-resistant OC tissues and cells. Also, the HULC depletion suppressed tumor growth and PTX resistance in PTX-treated mice. miR-137 was verified as a target of HULC and directly targeted ITGB8. And HULC knockdown downregulated ITGB8 expression by targeting miR-137. miR-137 inhibitor or ITGB8 overexpression mitigated the suppressive impacts of HULC knockdown on PTX resistance. Collectively, HULC modulated ITGB8 expression to promote PTX resistance of OC by sponging miR-137.

miR-4461 Regulates the Proliferation and Metastasis of Ovarian Cancer Cells and Cisplatin Resistance

microRNAs (miRNAs) are of great significance in cancer treatment, which may have a desirable result on the regulation of tumorigenesis, progression, recurrence, and chemo-resistance of ovarian cancer. However, the research on the further potential application of miR-4461 in ovarian cancer is little and limited. Therefore, the study in this paper focus on the investigation of the of miR-4461 in ovarian cancer progression and chemo-resistance. The phenomenon that the proliferation and metastasis of ovarian cancer cells can be promoted by miR4461 is revealed in functional assays. Through the bioinformatics and luciferase reporter analysis, the PTEN is validated to be the direct target of miR-4461 in ovarian. The association between the expression of miR-4461 and PTEN is negative in in human ovarian cancer tissues. The distinction of growth and metastasis capacity between miR-4461 knockdown ovarian cancer cells and control cells is partially abolished by si-PTEN. Moreover, it was found that cisplatin treatment has obvious effect on the miR-4461 knockdown ovarian cancer cells. In summary, the data given in this paper indicate that the miR-4461 can be regarded as a potential onco-miRNA in ovarian cancer by targeting PTEN.

Cancer Stem Cells-Key Players in Tumor Relapse

Tumor relapse and treatment failure are unfortunately common events for cancer patients, thus often rendering cancer an uncurable disease. Cancer stem cells (CSCs) are a subset of cancer cells endowed with tumor-initiating and self-renewal capacity, as well as with high adaptive abilities. Altogether, these features contribute to CSC survival after one or multiple therapeutic approaches, thus leading to treatment failure and tumor progression/relapse. Thus, elucidating the molecular mechanisms associated with stemness-driven resistance is crucial for the development of more effective drugs and durable responses. This review will highlight the mechanisms exploited by CSCs to overcome different therapeutic strategies, from chemo- and radiotherapies to targeted therapies and immunotherapies, shedding light on their plasticity as an insidious trait responsible for their adaptation/escape. Finally, novel CSC-specific approaches will be described, providing evidence of their preclinical and clinical applications.