MiR-200c sensitizes Olaparib-resistant ovarian cancer cells by targeting Neuropilin 1

Exploring the roles and clinical potential of exosome-derived non-coding RNAs in glioma

Non-coding accounts for 98 %-99 % of the human genome and performs many essential regulatory functions in eukaryotes, involved in cancer development and development. Non-coding RNAs are abundantly enriched in exosomes, which play a biological role as vectors. Some biofunctional non-coding RNAs are specifically designed as exosomes for the treatment of cancers such as glioma. Glioma is one of the most common primary tumors within the skull and has varying degrees of malignancy and histologic subtypes of grades I-IV. Gliomas are characterized by high malignancy and an abundant blood supply due to rapid cell proliferation and vascularization, often with a poor prognosis. Exosomal non-coding RNAs can be involved in the tumorigenesis process of glioma from multiple directions, such as angiogenesis, tumor proliferation, metastatic invasion, immune evasion, apoptosis, and autophagy. Therefore, non-coding RNAs in exosomes are suitable as markers or therapeutic targets for early diagnosis of diseases and for predicting the prognosis of a variety of diseases. Regulating exosome production and the level of exosomal non-coding RNA expression may be a new approach to prevent or eliminate glioma. In this review, we review the origin and characteristics of exosomal non-coding RNAs, and introduce the functional studies of exosomal non-coding RNAs in glioma and their potential clinical applications, in order to broaden new ideas for the treatment of glioma.

Layered Double Hydroxide LDH-Loaded miR-141-3p Targets RAB10 Suppressing Cellular Autophagy to Reverse Paclitaxel Resistance in Breast Cancer

Autophagy is a cellular protective mechanism. As tumor cells are stimulated by drugs, autophagy is activated to increase their resistance to drugs. In gene regulation, microRNA (miRNA) plays a vital role. The diagnostic and prognostic potential of various miRNAs in cancer has been recognized, and for several years, miRNA-based therapeutic approaches have garnered significant interest in the oncology field. RAB10, a member of the RAB guanosine triphosphatase family, has been reported that it contributes to tumor resistance to chemotherapy. The bionanomaterial layered double hydroxide (LDH) is considered as an ideal gene delivery vehicle because of its nontoxicity, good biocompatibility, and slow drug release. According to our findings, we proved that miR-141-3p mediated breast cancer resistance to paclitaxel (PTX) by inhibiting autophagy through downregulation of RAB10, and LDH@miR-141-3p increased breast cancer cell sensitivity to PTX treatment, which provided a new idea for antitumor therapy.

Combating tumor PARP inhibitor resistance: Combination treatments, nanotechnology, and other potential strategies

PARP (poly (ADP-ribose) polymerase) inhibitors (PARPi) have demonstrated significant potential in cancer treatment, particularly in tumors with breast cancer susceptibility gene (BRCA) mutations and other DNA repair deficiencies. However, the development of resistance to PARPi has become a major challenge in their clinical application. The emergence of drug resistance leads to reduced efficacy of the PARPi over time, impacting long-term treatment outcomes and survival rates. PARPi resistance in tumors often arises as cells activate alternative DNA repair pathways or evade the effect of PARPi, diminishing therapeutic effectiveness. Consequently, overcoming resistance is crucial for maintaining treatment efficacy and improving patient prognosis. This paper reviews the strategies to overcome PARPi resistance through combination treatment and nanotechnology therapy. We first review the current combination therapies with PARPi, including anti-angiogenic therapies, radiotherapies, immunotherapies, and chemotherapies, and elucidate their mechanisms for overcoming PARPi resistance. Additionally, this paper focuses on the application of nanotechnology in improving the effectiveness of PARPi and overcoming drug resistance. Subsequently, this paper presents several promising strategies to tackle PARPi resistance, including but not limited to: structural modifications of PARPi, deployment of gene editing systems, implementation of "membrane lipid therapy," and modulation of cellular metabolism in tumors. By integrating these strategies, this research will provide comprehensive approaches to overcome the resistance of PARPi in cancer treatment and offer guidance for future research and clinical practice.

A Multifunctional miRNA Delivery System Based on Tetrahedral Framework Nucleic Acids for Regulating Inflammatory Periodontal Ligament Stem Cells and Attenuating Periodontitis Bone Loss

Periodontitis is a chronic inflammatory disease that leads to periodontal tissue damage and tooth loss. Therefore, controlling inflammatory bone loss and promoting osteogenesis is a crucial challenge clinically. MicroRNA (miRNA) based gene therapy has shown substantial prospects in recent years, but its application has been limited due to structural instability and easy degradation by enzymes. Research has shown that miRNA-200c is regarded as a key miRNA by regulating multiple signaling pathways during the process of bone resorption. Tetrahedral framework nucleic acid (tFNA) can be considered an ideal carrier of miRNA due to its good tissue permeability, cell uptake efficiency, and biocompatibility. This study developed a tFNA system carrying miR-200c, named T-200c, to exert various biological effects in human periodontal ligament stem cells (PDLSCs). The activation of the NF-κB pathway is diminished, whereas the Akt/β-catenin pathway is enhanced, resulting in a notable decrease in the release of diverse inflammatory mediators and cellular reactive oxygen species. This modulation fosters cell proliferation and osteogenic differentiation, thereby rejuvenating the functionality of PDLSCs. These changes offer a viable alternative for the treatment of periodontitis and the regeneration of periodontal tissues.

A novel DNA damage-related gene index for predicting prognosis in gastric cancer

Gastric cancer is one of the major cancers with high cancer mortality and shows significant heterogeneity. The development of precise prognostic models is crucial for advancing treatment strategies. Recognizing the pivotal role of DNA damage in tumor progression, we conducted a consensus clustering analysis of DNA damage-related genes to categorize gastric cancer patients from the TCGA clinical cohort into distinct subtypes. Prognostic models were then constructed utilizing machine learning algorithms following Cox regression with differentially expressed genes. Validation was performed using the GSE gastric cancer cohort. Additionally, we investigated other characteristic responses of patients through gene mapping and drug sensitivity analysis. This study 12 differentially prognostic signature genes between the 2 DNA damage subtypes identified were used to calculate risk scores for the patients. This score predicts the prognosis of patients with gastric cancer and their overall survival time. Higher risk scores mean less drug sensitivity, lower survival, and possibly a poorer response to immunotherapy. Our findings provide the basis for future studies targeting DNA damage and its immune microenvironment to improve prognosis and response to immunotherapy.

MicroRNA-200c promotes trophoblast cell dysfunction via inhibition of PI3K/Akt signaling in unexplained recurrent spontaneous abortion

Dysfunction in trophoblast cells is closely associated with the development of recurrent spontaneous abortion (RSA). Previous reports have indicated that microRNA (miR)-200c was upregulated in the serum of patients who have had abortions. This study aimed to investigate the regulatory effects and mechanisms of miR-200c in trophoblast cells. The human extravillous trophoblast cell line HTR-8/SVneo was either subjected to knockdown or overexpression of miR-200c, and its levels were measured using RT-qPCR. The cell behaviors of HTR-8/SVneo were assessed using CCK-8, Transwell, wound healing assays, and flow cytometry. Western blotting was used to detect the protein levels of Ki67, Bcl-2, Bax, MMP2/9, and PI3K/Akt-related markers. The findings revealed that miR-200c levels were higher in the villous tissues of URSA patients. Depletion of miR-200c impeded HTR-8/SVneo cell apoptosis and enhanced cell migration, invasiveness, and proliferation, while overexpression of miR-200c exhibited the opposite effects. The data suggested that mechanistically, miR-200c inactivated PI3K/Akt signaling in trophoblast cells. Furthermore, rescue experiments demonstrated that blocking PI3K/Akt signaling reversed the effects of miR-200c depletion on HTR-8/SVneo cell behavior. Therefore, miR-200c depletion can potentially improve trophoblast cell function by activating PI3K/Akt signaling.

Discovery of novel PARP1/NRP1 dual-targeting inhibitors with strong antitumor potency

Given that overexpression of Poly (ADP-ribose) polymerase-1 (PARP1) and Neuropilin-1 (NRP1) is implicated in the pathogenesis of human breast cancer, the design of dual PARP1/NRP1 inhibitors has wide therapeutic prospect. However, there have been no reports of such inhibitors so far. Herein, we discovered novel small molecule inhibitors that simultaneously target PARP1 and NRP1 using structure-based virtual screening for the treatment of breast cancer. Notably, PPNR-4 was the most potent inhibitor targeting PARP1 (IC50 = 7.71 ± 0.39 nM) and NRP1 (IC50 = 24.48 ± 2.16 nM). PPNR-4 showed high affinity and binding stability to PARP1 and NRP1. The cytotoxicity assays showed that PPNR-4 demonstrated significant antiproliferative activity on MDA-MB-231 cells (IC50 = 0.21 μM) without effect on normal human cells. In vivo experiments exhibited that PPNR-4 showed more effective than the positive controls in inhibiting the growth of tumors. Overall, these data suggest that PPNR-4 is an effective antitumor candidate and deserves further research.

Evolving landscape of detection and targeting miRNA/epigenetics for therapeutic strategies in ovarian cancer

Ovarian cancer (OC) accounts for the highest mortality rates among all gynecologic malignancies. The high mortality of OC is often associated with delayed detection, prolonged latency, enhanced metastatic potential, acquired drug resistance, and frequent recurrence. This review comprehensively explores key aspects of OC, including cancer diagnosis, mechanisms of disease resistance, and the pivotal role of epigenetic regulation, particularly by microRNAs (miRs) in cancer progression. We highlight the intricate regulatory mechanisms governing miR expression within the context of OC and the current status of epigenetic advancement in the therapeutic development and clinical trial progression. Through network analysis we elucidate the regulatory interactions between dysregulated miRs in OC and their targets which are involved in different signaling pathways. By exploring these interconnected facets and critical analysis, we endeavor to provide a nuanced understanding of the molecular dynamics underlying OC, its detection and shedding light on potential avenues for miRs and epigenetics-based therapeutic intervention and management strategies.

circ_0006089 facilitates gastric cancer progression and oxaliplatin resistance via miR-217/NRP1

BACKGROUND

Oxaliplatin (OXA) is a vital tool in the chemotherapy of gastric cancer (GC) patients. Circular RNAs (circRNAs) are a group of non-coding RNAs that have been associated with tumorigenesis. Nevertheless, the function of circRNAs in OXA resistance of GC is unknown.

METHODS

Circ_0006089/miR-217/NRP1 were elucidated through qRT-PCR in GC OXA-tolerant tissues and cell lines. OXA half-inhibitory concentration (IC50) was quantified by MTT assay. RNA pull-down and luciferase reporter tests were applied to characterize the interaction between circ_0006089 and miR-217, miR-217 and NRP1 in GC cells.

RESULTS

The findings disclosed that circ_0006089 and NRP1 was heightened whereas miR-217 was dramatically declined in OXA-tolerant GC tissues and cell lines. OXA resistance was reduced and the proliferation, migration and invasion ability of OXA cells were diminished after silencing circ_0006089. In addition, circ_0006089 raised OXA resistance by sponging miR-217. Further studies revealed that miR-217 bound to NRP1 and weakened OXA resistance. In addition, it was found that circ_0006089 accelerated GC progression and OXA resistance by upregulating NRP1 expression via sponging miR-217.

CONCLUSION

Circ_0006089 regulated OXA resistance in GC cells through miR-217/NRP1 axis, implying it was a promising biomarker for GC therapy.

Construction of a novel cancer-associated fibroblast-related signature to predict clinical outcome and immune response in cervical cancer

This study developed a prognostic signature for cervical cancer using transcriptome profiling and clinical data from The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), and TISCH database, focusing on cancer-associated fibroblasts (CAFs). Through LASSO Cox regression and integrated bioinformatics analyses, we identified 144 differentially expressed genes (DEGs) related to CAFs, from which an 11-gene CAF-related signature (CAFRSig) was constructed. The CAFRSig effectively stratified patients into high- and low-risk categories, demonstrating significant prognostic capability in predicting overall survival. Gene ontology (GO) and gene set variation analysis (GSVA) linked the DEGs to crucial pathways in tumor malignancy, immune response, and fatty acid metabolism. The immune landscape analysis, utilizing the TIMER platform and CIBERSORT algorithm, revealed a positive correlation between immune cell effector functions and CAFRSig scores, highlighting the model's potential to identify patients likely to respond to immune checkpoint blockade (ICB) therapies. Furthermore, neuropilin 1 (NRP1), a key gene in the CAFRSig, was upregulated in cervical cancer tissues and associated with disease progression and differentiation. The downregulation of NRP1 curbed cell proliferation and influenced the epithelial-mesenchymal transition (EMT), implicating the PI3K/AKT pathway and modulating PD-L1 expression. This comprehensive analysis establishes a robust prognostic signature based on CAF-related genes, offering valuable insights for optimizing therapeutic strategies in cervical cancer management.

IP3R1 dysregulation via mir-200c-3p/SSFA2 axis contributes to taxol resistance in head and neck cancer

Head and neck cancer (HNC) is the sixth most common malignancy worldwide. Although current modalities offer a wide variety of therapy choices, head and neck carcinoma has poor prognosis due to its diagnosis at later stages and development of resistance to current therapeutic tools. In the current study, we aimed at exploring the roles of miR-200c-3p during head and neck carcinogenesis and acquisition of taxol resistance. We analyzed miR-200c-3p levels in HNC clinical samples and cell lines using quantitative real-time polymerase chain reaction and evaluated the effects of differential miR-200c-3p expression on cancer-related cellular phenotypes using in-vitro tools. We identified and characterized a direct target of miR-200c-3p using in-silico tools, luciferase and various in-vitro assays. We investigated potential involvement of miR-200c-3p/SSFA2 axis in taxol resistance in-vitro. We found miR-200c-3p expression as significantly downregulated in both HNC tissues and cells compared to corresponding controls. Ectopic miR-200c-3p expression in HNC cells significantly inhibited cancer-related phenotypes such as viability, clonogenicity, migration, and invasion. We, then, identified SSFA2 as a direct target of miR-200c-3p and demonstrated that overexpression of SSFA2 induced malignant phenotypes in HNC cells. Furthermore, we found reduced miR-200c-3p expression in parallel with overexpression of SSFA2 in taxol resistant HNC cells compared to parental sensitive cells. Both involved in intracellular cytoskeleton remodeling, we found that SSFA2 works collaboratively with IP3R1 to modulate resistance to taxol in HNC cells. When considered collectively, our results showed that miR-200c-3p acts as a tumor suppressor microRNA and targets SSFA2/IP3R1 axis to sensitize HNC cells to taxol.

Uncovering miRNA-mRNA Regulatory Networks Related to Olaparib Resistance and Resensitization of BRCA2MUT Ovarian Cancer PEO1-OR Cells with the ATR/CHK1 Pathway Inhibitors

Resistance to olaparib is the major obstacle in targeted therapy for ovarian cancer (OC) with poly(ADP-ribose) polymerase inhibitors (PARPis), prompting studies on novel combination therapies to enhance olaparib efficacy. Despite identifying various mechanisms, understanding how OC cells acquire PARPi resistance remains incomplete. This study investigated microRNA (miRNA) expression in olaparib-sensitive (PEO1, PEO4) and previously established olaparib-resistant OC cell lines (PEO1-OR) using high-throughput RT-qPCR and bioinformatic analyses. The role of miRNAs was explored regarding acquired resistance and resensitization with the ATR/CHK1 pathway inhibitors. Differentially expressed miRNAs were used to construct miRNA-mRNA regulatory networks and perform functional enrichment analyses for target genes with miRNet 2.0. TCGA-OV dataset was analyzed to explore the prognostic value of selected miRNAs and target genes in clinical samples. We identified potential processes associated with olaparib resistance, including cell proliferation, migration, cell cycle, and growth factor signaling. Resensitized PEO1-OR cells were enriched in growth factor signaling via PDGF, EGFR, FGFR1, VEGFR2, and TGFβR, regulation of the cell cycle via the G2/M checkpoint, and caspase-mediated apoptosis. Antibody microarray analysis confirmed dysregulated growth factor expression. The addition of the ATR/CHK1 pathway inhibitors to olaparib downregulated FGF4, FGF6, NT-4, PLGF, and TGFβ1 exclusively in PEO1-OR cells. Survival and differential expression analyses for serous OC patients revealed prognostic miRNAs likely associated with olaparib resistance (miR-99b-5p, miR-424-3p, and miR-505-5p) and resensitization to olaparib (miR-324-5p and miR-424-3p). Essential miRNA-mRNA interactions were reconstructed based on prognostic miRNAs and target genes. In conclusion, our data highlight distinct miRNA profiles in olaparib-sensitive and olaparib-resistant cells, offering molecular insights into overcoming resistance with the ATR/CHK1 inhibitors in OC. Moreover, some miRNAs might serve as potential predictive signature molecules of resistance and therapeutic response.

The emerging roles of miRNA-mediated autophagy in ovarian cancer

Ovarian cancer is one of the common tumors of the female reproductive organs. It has a high mortality rate, is highly heterogeneous, and early detection and primary prevention are very complex. Autophagy is a cellular process in which cytoplasmic substrates are targeted for degradation in lysosomes through membrane structures called autophagosomes. The periodic elimination of damaged, aged, and redundant cellular molecules or organelles through the sequential translation between amino acids and proteins by two biological processes, protein synthesis, and autophagic protein degradation, helps maintain cellular homeostasis. A growing number of studies have found that autophagy plays a key regulatory role in ovarian cancer. Interestingly, microRNAs regulate gene expression at the posttranscriptional level and thus can regulate the development and progression of ovarian cancer through the regulation of autophagy in ovarian cancer. Certain miRNAs have recently emerged as important regulators of autophagy-related gene expression in cancer cells. Moreover, miRNA analysis studies have now identified a sea of aberrantly expressed miRNAs in ovarian cancer tissues that can affect autophagy in ovarian cancer cells. In addition, miRNAs in plasma and stromal cells in tumor patients can affect the expression of autophagy-related genes and can be used as biomarkers of ovarian cancer progression. This review focuses on the potential significance of miRNA-regulated autophagy in the diagnosis and treatment of ovarian cancer.

Deciphering resistance mechanisms and novel strategies to overcome drug resistance in ovarian cancer: a comprehensive review

Ovarian cancer is among the most lethal gynecological cancers, primarily due to the lack of specific symptoms leading to an advanced-stage diagnosis and resistance to chemotherapy. Drug resistance (DR) poses the most significant challenge in treating patients with existing drugs. The Food and Drug Administration (FDA) has recently approved three new therapeutic drugs, including two poly (ADP-ribose) polymerase (PARP) inhibitors (olaparib and niraparib) and one vascular endothelial growth factor (VEGF) inhibitor (bevacizumab) for maintenance therapy. However, resistance to these new drugs has emerged. Therefore, understanding the mechanisms of DR and exploring new approaches to overcome them is crucial for effective management. In this review, we summarize the major molecular mechanisms of DR and discuss novel strategies to combat DR.

DNA G-Quadruplex in NRP1 Promoter Facilitates SARS-CoV-2 Infection

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection continues to raise concerns worldwide. Numerous host factors involved in SARS-CoV-2 infection have been identified, but the regulatory mechanisms of these host factor remain unclear. Here, we report the role of G-quadruplexes (G4s) located in the host factor promoter region in SARS-CoV-2 infection. Using bioinformatics, biochemical, and biological assays, we provide evidence for the presence of G4 structures in the promoter regions of SARS-CoV-2 host factors NRP1. Specifically, we focus on two representative G4s in the NRP1 promoter and highlight its importance in SARS-CoV-2 pathogenesis. The presence of the G4 structure greatly increases NRP1 expression, facilitating SARS-CoV-2 entry into cells. Utilizing published single-cell RNA sequencing data obtained from simulated SARS-CoV-2 infection in human bronchial epithelial cells (HBECs), we found that ciliated cells with high levels of NRP1 are prominently targeted by the virus during infection. Furthermore, our study identifies E2F1 act as a transcription factor that binds to G4s. These findings uncover a previously unknown mechanism underlying SARS-CoV-2 infection and suggest that targeting G4 structures could be a potential strategy for COVID-19 prevention and treatment.

A miRNA-7704/IL2RB/AKT feedback loop regulates tumorigenesis and chemoresistance in ovarian cancer

Ovarian cancer is one of the most common gynecological tumors worldwide. Despite the availability of multiple treatments for ovarian cancer, its resistance to chemotherapy remains a significant challenge. miRNAs play crucial roles in the initiation and progression of cancer by affecting processes such as differentiation, proliferation, and chemoresistance. According to microarray and qPCR analyses, miR-7704 is significantly downregulated in cisplatin-resistant cells compared to parental cells. In this study, we found that miR-7704 inhibited the proliferation and promoted cisplatin sensitivity of ovarian cancer cells in vitro and in vivo. Moreover, ectopic expression of miR-7704 had the same effect as IL2RB knockdown. Further mechanistic studies revealed that miR-7704 played an inhibitory role by regulating IL2RB expression to inactivate the AKT signaling pathway. Furthermore, IL2RB reversed the miR-7704 mediated resistance to cisplatin in ovarian cancer. Based on these findings, miR-7704 and IL2RB show the potential as novel therapeutic targets for ovarian cancer.

Drug resistance in ovarian cancer: from mechanism to clinical trial

Ovarian cancer is the leading cause of gynecological cancer-related death. Drug resistance is the bottleneck in ovarian cancer treatment. The increasing use of novel drugs in clinical practice poses challenges for the treatment of drug-resistant ovarian cancer. Continuing to classify drug resistance according to drug type without understanding the underlying mechanisms is unsuitable for current clinical practice. We reviewed the literature regarding various drug resistance mechanisms in ovarian cancer and found that the main resistance mechanisms are as follows: abnormalities in transmembrane transport, alterations in DNA damage repair, dysregulation of cancer-associated signaling pathways, and epigenetic modifications. DNA methylation, histone modifications and noncoding RNA activity, three key classes of epigenetic modifications, constitute pivotal mechanisms of drug resistance. One drug can have multiple resistance mechanisms. Moreover, common chemotherapies and targeted drugs may have cross (overlapping) resistance mechanisms. MicroRNAs (miRNAs) can interfere with and thus regulate the abovementioned pathways. A subclass of miRNAs, "epi-miRNAs", can modulate epigenetic regulators to impact therapeutic responses. Thus, we also reviewed the regulatory influence of miRNAs on resistance mechanisms. Moreover, we summarized recent phase I/II clinical trials of novel drugs for ovarian cancer based on the abovementioned resistance mechanisms. A multitude of new therapies are under evaluation, and the preliminary results are encouraging. This review provides new insight into the classification of drug resistance mechanisms in ovarian cancer and may facilitate in the successful treatment of resistant ovarian cancer.

Macrophage-derived exosomal miRNA-141 triggers endothelial cell pyroptosis by targeting NLRP3 to accelerate sepsis progression

Sepsis, critical condition marked by severe organ dysfunction from uncontrolled infection, involves the endothelium significantly. Macrophages, through paracrine actions, play a vital role in sepsis, but their mechanisms in sepsis pathogenesis remain elusive. Objective: We aimed to explore how macrophage-derived exosomes with low miR-141 expression promote pyroptosis in endothelial cells (ECs). Exosomes from THP-1 cell supernatant were isolated and characterized. The effects of miR-141 mimic/inhibitor on apoptosis, proliferation, and invasion of Human Umbilical Vein Endothelial Cells (HUVECs) were assessed using flow cytometry, CCK-8, and transwell assays. Key pyroptosis-related proteins, including caspase-1, IL-18, IL-1β, NLR Family Pyrin Domain Containing 3 (NLRP3), ASC, and cleaved-GSDMD, were analyzed via Western blot. The interaction between miR-141 and NLRP3 was studied using RNAhybrid v2.2 and dual-Luciferase reporter assays. The mRNA and protein level of NLRP3 after exosomal miR-141 inhibitor treatment was detected by qPCR and Western blot, respectively. Exosomes were successfully isolated. miR-141 mimic reduced cell death and pyroptosis-related protein expression in HUVECs, while the inhibitor had opposite effects, increasing cell death, and enhancing pyroptosis protein expression. Additionally, macrophage-derived exosomal miR-141 inhibitor increased cell death and pyroptosis-related proteins in HUVECs. miR-141 inhibits NLRP3 transcription. Macrophages facilitate sepsis progression by secreting miR-141 decreased exosomes to activate NLRP3-mediated pyroptosis in ECs, which could be a potentially valuable target of sepsis therapy.

The Roles of Autophagy-related miRNAs in Gynecologic Tumors: A Review of Current Knowledge for Possible Targeted Therapy

Gynecological cancers are the leading cause of malignancy-related death and disability in the world. These cancers are diagnosed at end stages, and unfortunately, the standard therapeutic strategies available for the treatment of affected women [including chemotherapy, radiotherapy and surgery] are not safe and effective enough. Moreover, the unwanted side-effects lowering the patients' life quality is another problem for these therapies. Therefore, researchers should search for better alternative/complementary treatments. The involvement of autophagy in the pathogenesis of various cancers has been demonstrated. Recently, a novel crosstalk between microRNAs, small non-coding RNAs with important regulatory functions, and autophagy machinery has been highlighted. In this review, we indicate the importance of this interaction for targeted therapy in the treatment of cancers including gynecological cancers, with a focus on underlying mechanisms.

The role and function of autophagy through signaling and pathogenetic pathways and lncRNAs in ovarian cancer

Lysosomal-driven autophagy is a tightly controlled cellular catabolic process that breaks down and recycles broken or superfluous cell parts. It is involved in several illnesses, including cancer, and is essential in preserving cellular homeostasis. Autophagy prevents DNA mutation and cancer development by actively eliminating pro-oxidative mitochondria and protein aggregates from healthy cells. Oncosuppressor and oncogene gene mutations cause dysregulation of autophagy. Increased autophagy may offer cancer cells a pro-survival advantage when oxygen and nutrients are scarce and resistance to chemotherapy and radiation. This finding justifies the use of autophagy inhibitors in addition to anti-neoplastic treatments. Excessive autophagy levels can potentially kill cells. The diagnosis and treatment of ovarian cancer present many difficulties due to its complexity and heterogeneity. Understanding the role of autophagy, a cellular process involved in the breakdown and recycling of cellular components, in ovarian cancer has garnered increasing attention in recent years. Of particular note is the increasing amount of data indicating a close relationship between autophagy and ovarian cancer. Autophagy either promotes or restricts tumor growth in ovarian cancer. Dysregulation of autophagy signaling pathways in ovarian cancers can affect the development, metastasis, and response to tumor treatment. The precise mechanism underlying autophagy concerning ovarian cancer remains unclear, as does the role autophagy plays in ovarian carcinoma. In this review, we tried to encapsulate and evaluate current findings in investigating autophagy in ovarian cancer.

Targeted inhibition of the ATR/CHK1 pathway overcomes resistance to olaparib and dysregulates DNA damage response protein expression in BRCA2MUT ovarian cancer cells

Olaparib is a PARP inhibitor (PARPi) approved for targeted treatment of ovarian cancer (OC). However, its efficacy is impeded by the inevitable occurrence of resistance. Here, we investigated whether the cytotoxic activity of olaparib could be synergistically enhanced in olaparib-resistant OC cells with BRCA2 reversion mutation by the addition of inhibitors of the ATR/CHK1 pathway. Moreover, we provide insights into alterations in the DNA damage response (DDR) pathway induced by combination treatments. Antitumor activity of olaparib alone or combined with an ATR inhibitor (ATRi, ceralasertib) or CHK1 inhibitor (CHK1i, MK-8776) was evaluated in OC cell lines sensitive (PEO1, PEO4) and resistant (PEO1-OR) to olaparib. Antibody microarrays were used to explore changes in expression of 27 DDR-related proteins. Olaparib in combination with ATR/CHK1 inhibitors synergistically induced a decrease in viability and clonogenic survival and an increase in apoptosis mediated by caspase-3/7 in all OC cells. Combination treatments induced cumulative alterations in expression of DDR-related proteins mediating distinct DNA repair pathways and cell cycle control. In the presence of ATRi and CHK1i, olaparib-induced upregulation of proteins determining cell fate after DNA damage (PARP1, CHK1, c-Abl, Ku70, Ku80, MDM2, and p21) was abrogated in PEO1-OR cells. Overall, the addition of ATRi or CHK1i to olaparib effectively overcomes resistance to PARPi exerting anti-proliferative effect in BRCA2MUT olaparib-resistant OC cells and alters expression of DDR-related proteins. These new molecular insights into cellular response to olaparib combined with ATR/CHK1 inhibitors might help improve targeted therapies for olaparib-resistant OC.

ceRNA networks in gynecological cancers progression and resistance

Gynecological cancers are the second most common types of cancer in women. Clinical diagnosis of these cancers is often delayed or misdiagnosed due to lack of insight into their tumorigenesis mechanism and specific diagnostic biomarkers. Many studies have demonstrated that competing endogenous RNAs (ceRNAs) modulate the progression and resistance of gynecological cancer through microRNA (miRNA)-mediated mechanisms, which affect gene expression in multiple cancer-related pathways. Here we review studies on the involvement of the ceRNA hypothesis in the progression and resistance of gynaecological cancers to validate some ceRNAs as therapeutic targets and predictive biomarkers.

Long noncoding RNA LOC646029 functions as a ceRNA to suppress ovarian cancer progression through the miR-627-3p/SPRED1 axis

Long noncoding RNAs (lncRNAs) play a crucial regulatory role in the development and progression of multiple cancers. However, the potential mechanism by which lncRNAs affect the recurrence and metastasis of ovarian cancer remains unclear. In the current study, the lncRNA LOC646029 was markedly downregulated in metastatic ovarian tumors compared with primary tumors. Gain- and loss-of-function assays demonstrated that LOC646029 inhibits the proliferation, invasiveness, and metastasis of ovarian cancer cells in vivo and in vitro. Moreover, the downregulation of LOC646029 in metastatic ovarian tumors was strongly correlated with poor prognosis. Mechanistically, LOC646029 served as a miR-627-3p sponge to promote the expression of Sprouty-related EVH1 domain-containing protein 1, which is necessary for suppressing tumor metastasis and inhibiting KRAS signaling. Collectively, our results demonstrated that LOC646029 is involved in the progression and metastasis of ovarian cancer, which may be a potential prognostic biomarker.

"DEPHENCE" system-a novel regimen of therapy that is urgently needed in the high-grade serous ovarian cancer-a focus on anti-cancer stem cell and anti-tumor microenvironment targeted therapies

Ovarian cancer, especially high-grade serous type, is the most lethal gynecological malignancy. The lack of screening programs and the scarcity of symptomatology result in the late diagnosis in about 75% of affected women. Despite very demanding and aggressive surgical treatment, multiple-line chemotherapy regimens and both approved and clinically tested targeted therapies, the overall survival of patients is still unsatisfactory and disappointing. Research studies have recently brought some more understanding of the molecular diversity of the ovarian cancer, its unique intraperitoneal biology, the role of cancer stem cells, and the complexity of tumor microenvironment. There is a growing body of evidence that individualization of the treatment adjusted to the molecular and biochemical signature of the tumor as well as to the medical status of the patient should replace or supplement the foregoing therapy. In this review, we have proposed the principles of the novel regimen of the therapy that we called the "DEPHENCE" system, and we have extensively discussed the results of the studies focused on the ovarian cancer stem cells, other components of cancer metastatic niche, and, finally, clinical trials targeting these two environments. Through this, we have tried to present the evolving landscape of treatment options and put flesh on the experimental approach to attack the high-grade serous ovarian cancer multidirectionally, corresponding to the "DEPHENCE" system postulates.

MicroRNAs as Potential Biomarkers in Gynecological Cancers

MicroRNAs are non-coding transcripts that, thanks to the ability to regulate the mRNA of target genes, can affect the expression of genes encoding tumor suppressors and oncogenes. They can control many important cellular processes, including apoptosis, differentiation, growth, division, and metabolism. Therefore, miRNAs play an important role in the development of many cancers, including gynecological cancers. Ovarian cancer, endometrial cancer, cervical cancer, and vulvar cancer are the most common cancers in women and are a frequent cause of death. The heterogeneity of the pathogenesis of these gynecological diseases makes the diagnostic process a significant obstacle for modern medicine. To date, many studies have been carried out, in which particular attention has been paid to the molecular pathomechanism of these diseases, with particular emphasis on miRNAs. To date, the changed profile of many miRNAs, which influenced the promotion of proliferation, migration, invasion processes and the simultaneous inhibition of programmed cell death, has been proven many times. Detailed understanding of the molecular effects of miRNAs in the above-mentioned gynecological cancers will enable the development of potential predictive and prognostic biomarkers, as well as the optimization of the diagnostic process.

Non-coding RNAs: The recently accentuated molecules in the regulation of cell autophagy for ovarian cancer pathogenesis and therapeutic response

Autophagy is a self-recycling and conserved process, in which the senescent cytoplasmic components are degraded in cells and then recycled to maintain homeostatic balance. Emerging evidence has suggested the involvement of autophagy in oncogenesis and progression of various cancers, such as ovarian cancer (OC). Meanwhile, the non-coding RNAs (ncRNAs) frequently regulate the mRNA transcription and other functional signaling pathways in cell autophagy, displaying promising roles in human cancer pathogenesis and therapeutic response. This article mainly reviews the cutting-edge research advances about the interactions between ncRNAs and autophagy in OC. This review not only summarizes the underlying mechanisms of dynamic ncRNA-autophagy association in OC, but also discusses their prognostic implications and therapeutic biomarkers. The aim of this review was to provide a more in-depth knowledge framework exploring the ncRNA-autophagy crosstalk and highlight the promising treatment strategies for OC patients.

Olaparib-Resistant BRCA2MUT Ovarian Cancer Cells with Restored BRCA2 Abrogate Olaparib-Induced DNA Damage and G2/M Arrest Controlled by the ATR/CHK1 Pathway for Survival

The PARP inhibitor (PARPi) olaparib is currently the drug of choice for serous ovarian cancer (OC), especially in patients with homologous recombination (HR) repair deficiency associated with deleterious BRCA1/2 mutations. Unfortunately, OC patients who fail to respond to PARPi or relapse after treatment have limited therapeutic options. To elucidate olaparib resistance and enhance the efficacy of olaparib, intracellular factors exploited by OC cells to achieve decreased sensitivity to PARPi were examined. An olaparib-resistant OC cell line, PEO1-OR, was established from BRCA2MUT PEO1 cells. The anticancer activity and action of olaparib combined with inhibitors of the ATR/CHK1 pathway (ceralasertib as ATRi, MK-8776 as CHK1i) in olaparib-sensitive and -resistant OC cell lines were evaluated. Whole-exome sequencing revealed that PEO1-OR cells acquire resistance through subclonal enrichment of BRCA2 secondary mutations that restore functional full-length protein. Moreover, PEO1-OR cells upregulate HR repair-promoting factors (BRCA1, BRCA2, RAD51) and PARP1. Olaparib-inducible activation of the ATR/CHK1 pathway and G2/M arrest is abrogated in olaparib-resistant cells. Drug sensitivity assays revealed that PEO1-OR cells are less sensitive to ATRi and CHK1i agents. Combined treatment is less effective in olaparib-resistant cells considering inhibition of metabolic activity, colony formation, survival, accumulation of DNA double-strand breaks, and chromosomal aberrations. However, synergistic antitumor activity between compounds is achievable in PEO1-OR cells. Collectively, olaparib-resistant cells display co-existing HR repair-related mechanisms that confer resistance to olaparib, which may be effectively utilized to resensitize them to PARPi via combination therapy. Importantly, the addition of ATR/CHK1 pathway inhibitors to olaparib has the potential to overcome acquired resistance to PARPi.

m6A reader HNRNPA2B1 destabilization of ATG4B regulates autophagic activity, proliferation and olaparib sensitivity in breast cancer

N⁶-methyladenosine RNA (m⁶A) is the most extensive epigenetic modification in mRNA and influences tumor progression. However, the role of m⁶A regulators and specific mechanisms in breast cancer still need further study. Here, we investigated the significance of the m⁶A reader HNRNPA2B1 and explored its influence on autophagy and drug sensitivity in breast cancer. HNRNPA2B1 was selected by bioinformatics analysis, and its high expression level was identified in breast cancer tissues and cell lines. HNRNPA2B1 was related to poor prognosis. Downregulation of HNRNPA2B1 reduced proliferation, enhanced autophagic flux, and partially reversed de novo resistance to olaparib in breast cancer. ATG4B was determined by RIP and MeRIP assays as a downstream gene of HNRNPA2B1, by which recognized the m⁶A site in the 3'UTR. Overexpression of ATG4B rescued the malignancy driven by HNRNPA2B1 in breast cancer cells and increased the olaparib sensitivity. Our study revealed that the m⁶A reader HNRNPA2B1 mediated proliferation and autophagy in breast cancer cell lines by facilitating ATG4B mRNA decay and targeting HNRNPA2B1/m⁶A/ATG4B might enhance the olaparib sensitivity of breast cancer cells.

A Regulatory Loop Involving miR-200c and NF-κB Modulates Mortalin Expression and Increases Cisplatin Sensitivity in an Ovarian Cancer Cell Line Model

Ovarian cancer is currently the most lethal gynecological cancer. At present, primary debulking surgery combined with platinum-based chemotherapy is the standard treatment strategy for ovarian cancer. Although cisplatin-based chemotherapy has greatly improved the prognosis of patients, the subsequent primary or acquired drug resistance of cancer cells has become an obstacle to a favorable prognosis. Mortalin is a chaperone that plays an important role in multiple cellular and biological processes. Our previous studies have found that mortalin is associated with the proliferation and migration of ovarian cancer cells and their resistance to cisplatin-based chemotherapy. In this study, microRNA (miR)-200b/c downregulated mortalin expression and inhibited the proliferation and migration of the paired cisplatin-sensitive (A2780S) and cisplatin-resistant (A2780CP) epithelial ovarian cancer cell lines. Moreover, miR-200c increased the sensitivity of ovarian cancer cells to cisplatin treatment by regulating mortalin levels. Nuclear factor (NF)-κB directly regulated mortalin and miR-200b/c expression levels, while NF-κB and miR-200b/c jointly regulated the expression of mortalin. The combination of cisplatin and miR-200c significantly enhanced the therapeutic effects on ovarian cancer in vivo, suggesting that miR-200c may serve as a potential therapeutic agent for ovarian cancer.

Clinical impact of soluble Neuropilin-1 in ovarian cancer patients and its association with its circulating ligands of the HGF/c-MET axis

BACKGROUND

Neuropilin (NRP) is a transmembrane protein, which has been shown to be a pro-angiogenic mediator and implicated as a potential driver of cancer progression. NRP-1 up-regulation in ovarian cancer tissue predicts poor prognosis. However, the clinical relevance of the soluble form of NRP-1 (sNRP-1) as a circulating biomarker in ovarian cancer patients is unknown.

METHODS/PATIENTS COHORT

sNRP-1 levels were quantified in a cohort of 88 clinically documented ovarian cancer patients by a commercially available sNRP-1 enzyme-linked immunosorbent assay (ELISA) kit (Biomedica, Vienna, Austria). Patients (81.8% with FIGOIII/IV) received primary cytoreductive surgery with the aim of macroscopic complete resection (achieved in 55.7% of patients) and the recommendation of adjuvant chemotherapy in line with national guidelines.

RESULTS

Higher levels of sNRP-1 reflected more advanced disease (FIGO III/IV) and indicated a trend towards suboptimal surgical outcome, i.e. any residual tumor. sNRP-1 was neither related to the patients' age nor the BRCA1/2 mutational status. Patients with higher sNRP-1 levels at primary diagnosis had a significantly reduced progression-free survival (PFS) (HR = 0.541, 95%CI: 0.304 - 0.963; p = 0.037) and overall survival (OS) (HR = 0.459, 95%CI: 0.225 - 0.936; p = 0.032). Principal component analysis showed that sNRP-1 levels were unrelated to the circulating hepatocyte growth factor (HGF) and the soluble ectodomain of its receptor the tyrosine kinase mesenchymal-epithelial transition (c-MET), suggesting that there is no proportional serological concentration gradient of soluble components of the NRP-1/HGF/c-MET signaling axis.

CONCLUSIONS

In line with the previously shown tissue-based prognostic role, we demonstrated for the first time that sNRP-1 can also act as a readily accessible, prognostic biomarker in the circulation of patients with ovarian cancer at primary diagnosis. Given its known role in angiogenesis and conferring resistance to the poly ADP-ribose polymerase (PARP) inhibitor olaparib in vitro, our results encourage more detailed investigation into sNRP-1 as a potential predictive biomarker for bevacizumab and/or PARP-inhibitor treatment.

Characterization of the SARS-CoV-2 co-receptor NRP1 expression profiles in healthy people and cancer patients: Implication for susceptibility to COVID-19 disease and potential therapeutic strategy

Neuropilin-1 (NRP1) is a transmembrane protein involved in many physiological and pathological processes, and it functions as a co-receptor to facilitate the entry of SARS-CoV-2 into host cells. Therefore, it is critical to predict the susceptibility to SARS-CoV-2 and prognosis after infection among healthy people and cancer patients based on expression of NRP1. In the current study, we analyzed the conservation and isoform of NRP1 using public databases. NRP1 expression landscape in healthy people, COVID-19 patients, and cancer patients at both bulk and single-cell RNA-seq level was also depicted. We also analyzed the relationship between tissue-specific NRP1 expression and overall survival (OS), as well as tumor immune environment at a pan-cancer level, providing a comprehensive insight into the relationship between the vulnerability to SARS-CoV-2 infection and tumorigenesis. In conclusion, we identified NRP1 as a potential biomarker in predicting susceptibility to SARS-CoV-2 infection among healthy people and cancer patients.

Neuropilin-1 in the pathogenesis of preeclampsia, HIV-1, and SARS-CoV-2 infection: A review

This review explores the role of transmembrane neuropilin-1 (NRP-1) in pregnancy, preeclampsia (PE), human immunodeficiency virus type 1 (HIV-1) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections. Since these conditions are assessed independently, this review attempts to predict their comorbid clinical manifestations. Dysregulation of NRP-1 contributes to the pathogenesis of PE by (a) impairing vascular endothelial growth factor (VEGF) signaling for adequate spiral artery remodeling and placentation, (b) inducing syncytiotrophoblast (ST) cell apoptosis and increasing ST-derived microparticle circulation and (c) by decreasing regulatory T cell activity predisposing maternal immune intolerance. Although NRP-1 is upregulated in SARS-CoV-2 placentae, its exploitation for SARS-CoV-2 internalization and increased infectivity may alter angiogenesis through the competitive inhibition of VEGF. The anti-inflammatory nature of NRP-1 may aid its upregulation in HIV-1 infection; however, the HIV-accessory protein, tat, reduces NRP-1 expression. Upregulated NRP-1 in macrophages and dendritic cells also demonstrated HIV-1 resistance/reduced infectivity. Notably, HIV-1-infected pregnant women receiving antiretroviral therapy (ART) to prevent vertical transmission may experience immune reconstitution, impaired decidualization, and elevated markers of endothelial injury. Since endothelial dysfunction and altered immune responses are central to PE, HIV-1 infection, ART usage and SARS-CoV-2 infection, it is plausible that an exacerbation of both features may prevail in the synergy of these events. Additionally, this review identifies microRNAs (miRNAs) mediating NRP-1 expression. MiR-320 and miR-141 are overexpressed in PE, while miR-206 and miR-124-3p showed increased expression in PE and HIV-1 infection. Additionally, miR-214 is overexpressed in PE, HIV-1 and SARS-CoV-2 infection, implicating treatment strategies to reduce these miRNAs to upregulate and normalize NRP-1 expression. However, inconsistencies in the data of the role and regulation of miRNAs in PE, HIV-1 and SARS-CoV-2 infections require clarification. This review provides a platform for early diagnosis and potential therapeutic intervention of PE, HIV-1, and SARS-CoV-2 infections independently and as comorbidities.

Construction of PARPi Resistance-related Competing Endogenous RNA Network

Objective: Ovarian cancer is a kind of common gynecological malignancy in women. PARP inhibitors (PARPi) have been approved for ovarian cancer treatment. However, the primary and acquired resistance have limited the application of PARPi. The mechanisms remain to be elucidated. Methods: In this study, we characterized the expression profiles of mRNA and nonconding RNAs (ncRNAs) and constructed the regulatory networks based on RNA sequencing in PARPi Olaparib-induced ovarian cancer cells. Results: We found that the functions of the differentially expressed genes were enriched in "PI3K/AKT signaling pathway," "MAPK signaling pathway" and "metabolic process". The functions of DELs (cis) were enriched in "Human papillomavirus infection""tight junction" "MAPK signaling pathway". As the central regulator of ceRNAs, the differentially expressed miRNAs were enriched in "Human papillomavirus infection" "MAPK signaling pathway" "Ras signaling pathway". According to the degree of interaction, we identified 3 lncRNAs, 2 circRNAs, 7 miRNAs, and 12 mRNA as the key regulatory ceRNA axis, in which miR-320b was the important mediator. Conclusion: Here, we revealed the key regulatory lncRNA (circRNA)-miRNA-mRNA axis and their involved pathways in the PARPi resistant ovarian cancer cells. These findings provide new insights into exploring the ceRNA regulatory networks and developing new targets for PARPi resistance.

Mechanisms of chemotherapy resistance in ovarian cancer

Ovarian cancer is one of the most lethal gynecologic cancers. The standard therapy for ovarian cancer has been the same for the past two decades, a combination treatment of platinum with paclitaxel. Recently, the FDA approved three new therapeutic drugs, two poly (ADP-ribose) polymerase inhibitors (olaparib and niraparib) and one vascular endothelial growth factor inhibitor (bevacizumab) as maintenance therapies for ovarian cancer. In this review, we summarize the resistance mechanisms for conventional platinum-based chemotherapy and for the newly FDA-approved drugs.

CRISPR/Cas9 gene editing: a new approach for overcoming drug resistance in cancer

The CRISPR/Cas9 system is an RNA-based adaptive immune system in bacteria and archaea. Various studies have shown that it is possible to target a wide range of human genes and treat some human diseases, including cancers, by the CRISPR/Cas9 system. In fact, CRISPR/Cas9 gene editing is one of the most efficient genome manipulation techniques. Studies have shown that CRISPR/Cas9 technology, in addition to having the potential to be used as a new therapeutic approach in the treatment of cancers, can also be used to enhance the effectiveness of existing treatments. Undoubtedly, the issue of drug resistance is one of the main obstacles in the treatment of cancers. Cancer cells resist anticancer drugs by a variety of mechanisms, such as enhancing anticancer drugs efflux, enhancing DNA repair, enhancing stemness, and attenuating apoptosis. Mutations in some proteins of different cellular signaling pathways are associated with these events and drug resistance. Recent studies have shown that the CRISPR/Cas9 technique can be used to target important genes involved in these mechanisms, thereby increasing the effectiveness of anticancer drugs. In this review article, studies related to the applications of this technique in overcoming drug resistance in cancer cells will be reviewed. In addition, we will give a brief overview of the limitations of the CRISP/Cas9 gene-editing technique.

The Influence of PARP, ATR, CHK1 Inhibitors on Premature Mitotic Entry and Genomic Instability in High-Grade Serous BRCAMUT and BRCAWT Ovarian Cancer Cells

Olaparib is a poly (ADP-ribose) polymerase inhibitor (PARPi) that inhibits PARP1/2, leading to replication-induced DNA damage that requires homologous recombination repair. Olaparib is often insufficient to treat BRCA-mutated (BRCA^MUT) and BRCA wild-type (BRCA^WT) high-grade serous ovarian carcinomas (HGSOCs). We examined the short-term (up to 48 h) efficacy of PARPi treatment on a DNA damage response pathway mediated by ATR and CHK1 kinases in BRCA^MUT (PEO-1) and BRCA^WT (SKOV-3 and OV-90) cells. The combination of ATRi/CHK1i with PARPi was not more cytotoxic than ATR and CHK1 monotherapy. The combination of olaparib with inhibitors of the ATR/CHK1 pathway generated chromosomal abnormalities, independent on BRCA^MUT status of cells and formed of micronuclei (MN). However, the beneficial effect of the PARPi:ATRi combination on MN was seen only in the PEO1 BRCA^MUT line. Monotherapy with ATR/CHK1 inhibitors reduced BrdU incorporation due to a slower rate of DNA synthesis, which resulted from elevated levels of replication stress, while simultaneous blockade of PARP and ATR caused beneficial effects only in OV-90 cells. Inhibition of ATR/CHK1 increased the formation of double-strand breaks as measured by increased γH2AX expression at collapsed replication forks, resulting in increased levels of apoptosis. Our findings indicate that ATR and CHK1 inhibitors provoke premature mitotic entry, leading to genomic instability and ultimately cell death.

The Emerging Roles and Therapeutic Implications of Epigenetic Modifications in Ovarian Cancer

Ovarian cancer (OC) is one of the most lethal gynecologic malignancies globally. In spite of positive responses to initial therapy, the overall survival rates of OC patients remain poor due to the development of drug resistance and consequent cancer recurrence. Indeed, intensive studies have been conducted to unravel the molecular mechanisms underlying OC therapeutic resistance. Besides, emerging evidence suggests a crucial role for epigenetic modifications, namely, DNA methylation, histone modifications, and non-coding RNA regulation, in the drug resistance of OC. These epigenetic modifications contribute to chemoresistance through various mechanisms, namely, upregulating the expression of multidrug resistance proteins (MRPs), remodeling of the tumor microenvironment, and deregulated immune response. Therefore, an in-depth understanding of the role of epigenetic mechanisms in clinical therapeutic resistance may improve the outcome of OC patients. In this review, we will discuss the epigenetic regulation of OC drug resistance and propose the potential clinical implications of epigenetic therapies to prevent or reverse OC drug resistance, which may inspire novel treatment options by targeting resistance mechanisms for drug-resistant OC patients.

LncRNA NEAT1-miR-101-3p/miR-335-5p/miR-374a-3p/miR-628-5p-TRIM6 axis identified as the prognostic biomarker for lung adenocarcinoma via bioinformatics and meta-analysis

BACKGROUND

Overexpression of the tripartite motif containing 6 (TRIM6) is associated with dismal prognosis in cancer patients, but its exact roles in lung adenocarcinoma (LUAD) have not been reported.

METHODS

The roles of TRIM6 are identified by using The Cancer Genome Atlas (TCGA), TIMER2, Gene Expression Omnibus (GEO), etc., and the regulatory networks and related-prognostic biomarkers of TRIM6 are identified via the ENCORI and LNCAR databases in the LUAD progression.

RESULTS

TRIM6 expression level in LUAD tissues was significantly increased. TRIM6 over-expression level in LUAD patients was associated with smoking, clinical stage, histological type, lymph node metastasis, TP53 mutation and dismal prognosis, and related to prognosis-related age, race, sex, clinical stage and tumor purity of LUAD patients. TRIM6 overexpression was associated with the levels of CD8+ T cells, macrophages, neutrophils and myeloid dendritic cells, and correlated with the levels of LUAD immune cell markers CD8A, IRF5, CD163, VSIG4, MS4A4A, ITGAM, HLA-DPA1, NRP1, ITGAX, etc. TRIM6 might influence the progression of LUAD by regulating homologous recombination, oocyte meiosis, and ubiquitin-mediated proteolysis. LUAD patients with overexpression of miR-101-3p, miR-335-5p, miR-374a-3p, miR-628-5p, and NEAT1 had a poor prognosis.

CONCLUSIONS

NEAT1-miR-101-3p/335-5p/374a-3p/628-5p-TRIM6 network, which we constructed from our results, might be an important factor in the dismal prognosis of LUAD patients.

DNMT3A and DNMT3B Targeting as an Effective Radiosensitizing Strategy in Embryonal Rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in childhood. Recently, we demonstrated the overexpression of both DNA methyltransferase 3A (DNMT3A) and 3B (DNMT3B) in RMS tumour biopsies and cell lines compared to normal skeletal muscle. Radiotherapy may often fail due to the abnormal expression of some molecules able to drive resistance mechanisms. The aim of this study was to analyse the involvement of DNMT3A and DNMT3B in radioresistance in RMS. RNA interference experiments against DNMT3A/3B were performed in embryonal RMS cells, upon ionizing radiation (IR) exposure and the effects of the combined treatment on RMS cells were analysed. DNMT3A and DNMT3B knocking down increased the sensitivity of RMS cells to IR, as indicated by the drastic decrease of colony formation ability. Interestingly, DNMT3A/3B act in two different ways: DNMT3A silencing triggers the cellular senescence program by up-regulating p16 and p21, whilst DNMT3B depletion induces significant DNA damage and impairs the DNA repair machinery (ATM, DNA-PKcs and Rad51 reduction). Our findings demonstrate for the first time that DNMT3A and DNMT3B overexpression may contribute to radiotherapy failure, and their inhibition might be a promising radiosensitizing strategy, mainly in the treatment of patients with metastatic or recurrent RMS tumours.

MiR-200c-3p maintains stemness and proliferative potential in adipose-derived stem cells by counteracting senescence mechanisms

Adipose-derived mesenchymal stem cells (ASCs) are promising therapeutic tools in regenerative medicine because they possess self-renewal, differentiation and immunomodulatory capacities. After isolation, ASCs are passaged multiple times in vitro passages to obtain a sufficient amount of cells for clinical applications. During this time-consuming procedure, ASCs become senescent and less proliferative, compromising their clinical efficacy. Here, we sought to investigate how in vitro passages impact ASC proliferation/senescence and expression of immune regulatory proteins. MicroRNAs are pivotal regulators of ASC physiology. Particularly, miR-200c is known to maintain pluripotency and targets the immune checkpoint Programmed death-ligand 1 (PD-L1). We therefore investigated its involvement in these critical characteristics of ASCs during in vitro passages. We found that when transiently expressed, miR-200c-3p promotes proliferation, maintains stemness, and contrasts senescence in late passaged ASCs. Additionally, this miRNA modulates PD-L1 and Indoleamine 2,3-Dioxygenase (IDO1) expression, thus most likely interfering with the immunoregulatory capacity of ASCs. Based on our results, we suggest that expression of miR-200c-3p may prime ASC towards a self-renewing phenotype by improving their in vitro expansion. Contrarily, its inhibition is associated with senescence, reduced proliferation and induction of immune regulators. Our data underline the potential use of miR-200c-3p as a switch for ASCs reprogramming and their clinical application.

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.

Calcineurin Gamma Catalytic Subunit PPP3CC Inhibition by miR-200c-3p Affects Apoptosis in Epithelial Ovarian Cancer

Epithelial ovarian cancer (EOC) outpaces all the other forms of the female reproductive system malignancies. MicroRNAs have emerged as promising predictive biomarkers to therapeutic treatments as their expression might characterize the tumor stage or grade. In EOC, miR-200c is considered a master regulator of oncogenes or tumor suppressors. To investigate novel miR-200c-3p target genes involved in EOC tumorigenesis, we evaluated the association between this miRNA and the mRNA expression of several potential target genes by RNA-seq data of both 46 EOC cell lines from Cancer Cell line Encyclopedia (CCLE) and 456 EOC patient bio-specimens from The Cancer Genome Atlas (TCGA). Both analyses showed a significant anticorrelation between miR-200c-3p and the protein phosphatase 3 catalytic subunit γ of calcineurin (PPP3CC) levels involved in the apoptosis pathway. Quantitative mRNA expression analysis in patient biopsies confirmed the inverse correlation between miR-200c-3p and PPP3CC levels. In vitro regulation of PPP3CC expression through miR-200c-3p and RNA interference technology led to a concomitant modulation of BCL2- and p-AKT-related pathways, suggesting the tumor suppressive role of PPP3CC in EOC. Our results suggest that inhibition of high expression of miR-200c-3p in EOC might lead to overexpression of the tumor suppressor PPP3CC and subsequent induction of apoptosis in EOC patients.

Ascites in ovarian cancer: MicroRNA deregulations and their potential roles in ovarian carcinogenesis

Ovarian cancer comprises the most lethal gynecologic malignancy and is accompanied by the high potential for the incidence of metastasis, recurrence and chemotherapy resistance, often associated with a formation of ascitic fluid. The differentially expressed ascites-derived microRNAs may be linked to ovarian carcinogenesis. The article focuses on a number of miRNAs that share a common expression pattern as determined by independent studies using ascites samples and with regard to their functions and outcomes in experimental and clinical investigations.Let-7b and miR-143 have featured as tumor suppressors in ovarian cancer, which is in line with data on other types of cancer. Although two miRNAs, i.e. miR-26a-5p and miR-145-5p, act principally as tumor suppressor miRNAs, they occasionally exhibit oncogenic roles. The performance of miR-95-3p, upregulated in ascites, is open to debate given the current lack of supportive data on ovarian cancer; however, data on other cancers indicates its probable oncogenic role. Different findings have been reported for miR-182-5p and miR-200c-3p; in addition to their presumed oncogenic roles, contrasting findings have indicated their ambivalent functions. Further research is required for the identification and evaluation of the potential of specific miRNAs in the diagnosis, prediction, treatment and outcomes of ovarian cancer patients.

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.

Current Implications of microRNAs in Genome Stability and Stress Responses of Ovarian Cancer

Genomic alterations and aberrant DNA damage signaling are hallmarks of ovarian cancer (OC), the leading cause of mortality among gynecological cancers worldwide. Owing to the lack of specific symptoms and late-stage diagnosis, survival chances of patients are significantly reduced. Poly (ADP-ribose) polymerase (PARP) inhibitors and replication stress response inhibitors present attractive therapeutic strategies for OC. Recent research has focused on ovarian cancer-associated microRNAs (miRNAs) that play significant regulatory roles in various cellular processes. While miRNAs have been shown to participate in regulation of tumorigenesis and drug responses through modulating the DNA damage response (DDR), little is known about their potential influence on sensitivity to chemotherapy. The main objective of this review is to summarize recent findings on the utility of miRNAs as cancer biomarkers, in particular, ovarian cancer, and their regulation of DDR or modified replication stress response proteins. We further discuss the suppressive and promotional effects of various miRNAs on ovarian cancer and their participation in cell cycle disturbance, response to DNA damage, and therapeutic functions in multiple cancer types, with particular focus on ovarian cancer. Improved understanding of the mechanisms by which miRNAs regulate drug resistance should facilitate the development of effective combination therapies for ovarian cancer.

Altered Expression of Candidate Genes in Mayer-Rokitansky-Küster-Hauser Syndrome May Influence Vaginal Keratinocytes Biology: A Focus on Protein Kinase X

Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome is a rare and complex disease defined by congenital aplasia of the vagina and uterus in 46,XX women, often associated with kidney and urinary tract anomalies. The aetiopathogenesis of MRKH syndrome is still largely unknown. Herein, we investigated the role of selected candidate genes in the aetiopathogenesis of MRKH syndrome, with a focus on PRKX, which encodes for protein kinase X. Through RT-qPCR analyses performed on vaginal dimple samples from patients, and principal component analysis (PCA), we highlighted a phenotype-related expression pattern of PRKX, MUC1, HOXC8 and GREB1L in MRKH patients. By using an in vitro approach, we proved that PRKX ectopic overexpression in a cell model of vaginal keratinocytes promotes cell motility through epithelial-to-mesenchymal transition (EMT) activation, a fundamental process in urogenital tract morphogenesis. Moreover, our findings showed that PRKX upregulation in vaginal keratinocytes is able to affect transcriptional levels of HOX genes, implicated in urinary and genital tract development. Our study identified the dysregulation of PRKX expression as a possible molecular cause for MRKH syndrome. Moreover, we propose the specific role of PRKX in vaginal keratinocyte biology as one of the possible mechanisms underlying this complex disease.

OTX015 Epi-Drug Exerts Antitumor Effects in Ovarian Cancer Cells by Blocking GNL3-Mediated Radioresistance Mechanisms: Cellular, Molecular and Computational Evidence

Simple Summary

The outcome for women diagnosed with ovarian cancer (OC), the most aggressive gynecological tumor worldwide, remains very poor. Encouraging therapeutic impact of epigenetic drugs has been suggested in a wide range of human solid tumors, including OC. The present study assessed the in vitro cytostatic and cytotoxic effects of OTX015, a pan Bromodomain and Extra-Terminal motif inhibitor, in human OC cells, both as single treatment and in combination with radiotherapy. Cellular, molecular and computational network analyses indicated the centrality of GNL3 downregulation in mediating the OTX015-related antitumor efficacy that blocks disease progression/maintenance and radioresistance acquisition. Our preclinical results confirm that targeted and combinatorial treatments represent effective anticancer strategies to be translated in the clinical research for improving OC patient care.

Abstract

Ovarian cancer (OC) is the most aggressive gynecological tumor worldwide and, notwithstanding the increment in conventional treatments, many resistance mechanisms arise, this leading to cure failure and patient death. So, the use of novel adjuvant drugs able to counteract these pathways is urgently needed to improve patient overall survival. A growing interest is focused on epigenetic drugs for cancer therapy, such as Bromodomain and Extra-Terminal motif inhibitors (BETi). Here, we investigate the antitumor effects of OTX015, a novel BETi, as a single agent or in combination with ionizing radiation (IR) in OC cellular models. OTX015 treatment significantly reduced tumor cell proliferation by triggering cell cycle arrest and apoptosis that were linked to nucleolar stress and DNA damage. OTX015 impaired migration capacity and potentiated IR effects by reducing the expression of different drivers of cancer resistance mechanisms, including GNL3 gene, whose expression was found to be significantly higher in OC biopsies than in normal ovarian tissues. Gene specific knocking down and computational network analysis confirmed the centrality of GNL3 in OTX015-mediated OC antitumor effects. Altogether, our findings suggest OTX015 as an effective option to improve therapeutic strategies and overcome the development of resistant cancer cells in patients with OC.

MiR-200c-3p Contrasts PD-L1 Induction by Combinatorial Therapies and Slows Proliferation of Epithelial Ovarian Cancer through Downregulation of β-Catenin and c-Myc

Conventional/targeted chemotherapies and ionizing radiation (IR) are being used both as monotherapies and in combination for the treatment of epithelial ovarian cancer (EOC). Several studies show that these therapies might favor oncogenic signaling and impede anti-tumor responses. MiR-200c is considered a master regulator of EOC-related oncogenes. In this study, we sought to investigate if chemotherapy and IR could influence the expression of miR-200c-3p and its target genes, like the immune checkpoint PD-L1 and other oncogenes in a cohort of EOC patients’ biopsies. Indeed, PD-L1 expression was induced, while miR-200c-3p was significantly reduced in these biopsies post-therapy. The effect of miR-200c-3p target genes was assessed in miR-200c transfected SKOV3 cells untreated and treated with olaparib and IR alone. Under all experimental conditions, miR-200c-3p concomitantly reduced PD-L1, c-Myc and β-catenin expression and sensitized ovarian cancer cells to olaparib and irradiation. In silico analyses further confirmed the anti-correlation between miR-200c-3p with c-Myc and β-catenin in 46 OC cell lines and showed that a higher miR-200c-3p expression associates with a less tumorigenic microenvironment. These findings provide new insights into how miR-200c-3p could be used to hold in check the adverse effects of conventional chemotherapy, targeted therapy and radiation therapy, and offer a novel therapeutic strategy for EOC.