Long non-coding RNA XIST regulates ovarian cancer progression via modulating miR-335/BCL2L2 axis

Clinical significance of lncRNA XIST expression in cholangiocarcinoma and its effect on cell migration and invasion

BACKGROUND

Cholangiocarcinoma is a malignant tumor that occurs in the bile duct system, and the prognosis of patients is poor. Currently, research suggests that long non-coding RNAs (lncRNAs) in the treatment and prevention of cholangiocarcinoma. This study primarily focuses on the regulation and potential mechanism of the lncRNA XIST (XIST) in cholangiocarcinoma.

METHODS

The levels of XIST and miR-126-3p in cholangiocarcinoma tissues and cells were detected using real-time quantitative polymerase chain reaction (RT-qPCR). Cell transfection status, including migration and invasion, was examined via the Transwell method. The relationship between XIST and miR-126-3p was observed by dual-luciferase gene reporter assay and verified by rescue assays. Additionally, the prognostic significance of XIST in cholangiocarcinoma was determined using Kaplan-Meier and multivariate Cox regression analyses.

RESULTS

XIST expression was increased in cholangiocarcinoma, while miR-126-3p was decreased, in both tissues and cells. The successful construction of silencing XIST was found to inhibit the count of cell migration and invasion. XIST directly targeted miR-126-3p to regulate the progression of cholangiocarcinoma.

CONCLUSION

XIST sponging miR-126-3p inhibited the progression of cholangiocarcinoma and improved the prognosis for patients. This finding provides new insights and opportunities for future studies on cholangiocarcinoma prognostic biomarkers.

miRNAs: Potential as Biomarkers and Therapeutic Targets for Cancer

MicroRNAs (miRNAs) are single-stranded, non-coding RNA molecules that regulate gene expression post-transcriptionally by binding to messenger RNAs. miRNAs are important regulators of gene expression, and their dysregulation is implicated in many human and canine diseases. Most cancers tested to date have been shown to express altered miRNA levels, which indicates their potential importance in the oncogenic process. Based on this evidence, numerous miRNAs have been suggested as potential cancer biomarkers for both diagnosis and prognosis. miRNA-based therapies have also been tested in different cancers and have provided measurable clinical benefits to patients. In addition, understanding miRNA biogenesis and regulatory mechanisms in cancer can provide important knowledge about resistance to chemotherapies, leading to more personalized cancer treatment. In this review, we comprehensively summarized the importance of miRNA in human and canine cancer research. We discussed the current state of development and potential for the miRNA as both a diagnostic marker and a therapeutic target.

Therapeutic advancements in targeting BCL-2 family proteins by epigenetic regulators, natural, and synthetic agents in cancer

Cancer is amongst the deadliest and most disruptive disorders, having a much higher death rate than other diseases worldwide. Human cancer rates continue to rise, thereby posing the most significant concerns for medical health professionals. In the last two decades, researchers have gone past several milestones in tackling cancer while gaining insight into the role of apoptosis in cancer or targeting various biomarker tools for prognosis and diagnosis. Apoptosis which is still a topic full of complexities, can be controlled considerably by B-cell lymphoma 2 (BCL-2) and its family members. Therefore, targeting proteins of this family to prevent tumorigenesis, is essential to focus on the pharmacological features of the anti-apoptotic and pro-apoptotic members, which will help to develop and manage this disorder. This review deals with the advancements of various epigenetic regulators to target BCL-2 family proteins, including the mechanism of several microRNAs (miRNAs) and long non-coding RNAs (lncRNAs). Similarly, a rise in natural and synthetic molecules' research over the last two decades has allowed us to acquire insights into understanding and managing the transcriptional alterations that have led to apoptosis and treating various neoplastic diseases. Furthermore, several inhibitors targeting anti-apoptotic proteins and inducers or activators targeting pro-apoptotic proteins in preclinical and clinical stages have been summarized. Overall, agonistic and antagonistic mechanisms of BCL-2 family proteins conciliated by epigenetic regulators, natural and synthetic agents have proven to be an excellent choice in developing cancer therapeutics.

Potential roles of lncRNA-XIST/miRNAs/mRNAs in human cancer cells

Long non-coding RNAs (lncRNAs) are non-coding RNAs that contain more than 200 nucleotides but do not code for proteins. In tumorigenesis, lncRNAs can have both oncogenic and tumor-suppressive properties. X inactive-specific transcript (XIST) is a known lncRNA that has been implicated in X chromosome silencing in female cells. Dysregulation of XIST is associated with an increased risk of various cancers. Therefore, XIST can be a beneficial prognostic biomarker for human malignancies. In this review, we attempt to summarize the emerging roles of XIST in human cancers.

Diagnostic and prognostic values of MMP-9 expression in ovarian cancer: A study based on bioinformatics analysis and meta-analysis

Background

This study aims to explore the expression of matrix metalloproteinase-9 (MMP-9) associated with both diagnostic and prognostic value in ovarian cancer by meta-analysis and bioinformatics analyses.

Methods

We investigated the prognostic value of MMP-9 expression in ovarian cancer based on The Cancer Genome Atlas. Five databases were used to collect records about MMP-9 expression related to diagnostic and prognostic values in ovarian cancer from inception to June 2022. Using Stata 15.0 software, hazard ratio (HR) and odds ratio (OR) were calculated as the effect index of prognosis. We chose the pooled sensitivity, specificity, and area under the curve (AUC) to judge the diagnostic utility of MMP-9 for ovarian cancer.

Results

A total of 23 studies on prognosis, and five studies on diagnosis were entered into the meta-analysis. These suggest that high MMP-9 expression was detrimental to the overall survival of patients with ovarian cancer (HR = 1.34; 95% confidence interval (CI) 1.08∼1.66; P<0.01). High MMP-9 expression increased the risk of tumor stage (OR = 3.66; 95% CI 1.89∼7.07), but was not related to the tumor grade of ovarian cancer ( P>0.05). The pooled analysis of serum MMP-9 diagnosing for ovarian cancer gave the pooled sensitivity, specificity, and AUC the values of 0.72 (95% CI 0.61∼0.81), 0.81 (95% CI 0.77∼0.85), and 0.84 (95% CI 0.81∼0.87), respectively.

Conclusion

High MMP-9 expression can increase the tumor stage, and a correlation exists between high MMP-9 expression and poor prognosis in patients with ovarian cancer. Also, serum MMP-9 has a good diagnostic value for ovarian cancer.

Systematic Pan-Cancer Analysis and Experimental Verification Identify FOXA1 as an Immunological and Prognostic Biomarker in Epithelial Ovarian Cancer

Background. Epithelial ovarian cancer (EOC) has the lowest survival rate among female reproductive cancers present with symptoms of aggressive malignancies, poor prognosis, drug resistance and postoperative recurrence. The majority of patients with EOC are diagnosed at an advanced stage due to the therapeutic challenges including lack of early diagnosis and effective therapeutic targets for EOC. Methods. Pan-cancer analyses were performed to explore the features of forkhead-box (FOX) A1 (FOXA1) using data from TCGA and GTEx databases. R package “clusterprofiler” was used to perform the enrichment analysis of FOXA1 in EOC. Data downloaded from Drug Sensitivity in Cancer (GDSC) database were used to evaluate the association between FOXA1 and antitumor drug sensitivity. In experimental verification, FOXA1 expression was detected using qRT-PCR and western blot assays. Western blot, immunofluorescence staining, and Transwell assays were used to assess the influence of FOXA1 silencing on epithelial-mesenchymal transition (EMT) of EOC cells. Results. We found that FOXA1 was highly expressed in EOC and predicted poorer survival of EOC patients. We observed that FOXA1 expression was positively correlated EMT-related pathways. Through experimental verification, we found the underlying function of FOXA1 to promote EMT in ovarian cancers. The results from western blot, immunofluorescence staining, and Transwell assays showed that FOXA1 silencing impeded the progression of EMT and invasiveness of the cancer cells. Furthermore, CCK-8 and invasion assays suggested that siRNA-FOXA1 attenuated the ability of cancer cells to metastasize and proliferate. Dual-luciferase reporter assays confirmed the binding activity of FOXA1 to the promoter of connective tissue growth factor (CTGF). In addition, we found that FOXA1 was closely correlated immunosuppressive microenvironment of EOC. High FOXA1 expression may contribute to the resistance of many anticancer drugs. Conclusions. Our results predict and validate the function of FOXA1 in promoting EMT and the progression of disease in EOC. Targeting FOXA1 may improve the sensitivity of EOC treatment.

LncRNA-miRNA axis in tumor progression and therapy response: An emphasis on molecular interactions and therapeutic interventions

Epigenetic factors are critical regulators of biological and pathological mechanisms and they could interact with different molecular pathways. Targeting epigenetic factors has been an idea approach in disease therapy, especially cancer. Accumulating evidence has highlighted function of long non-coding RNAs (lncRNAs) as epigenetic factors in cancer initiation and development and has focused on their association with downstream targets. microRNAs (miRNAs) are the most well-known targets of lncRNAs and present review focuses on lncRNA-miRNA axis in malignancy and therapy resistance of tumors. LncRNA-miRNA regulates cell death mechanisms such as apoptosis and autophagy in cancers. This axis affects tumor metastasis via regulating EMT and MMPs. Besides, lncRNA-miRNA axis determines sensitivity of tumor cells to chemotherapy, radiotherapy and immunotherapy. Based on the studies, lncRNAs can be affected by drugs and genetic tools in cancer therapy and this may affect expression level of miRNAs as their downstream targets, leading to cancer suppression/progression. LncRNAs have both tumor-promoting and tumor-suppressor functions in cancer and this unique function of lncRNAs has complicated their implication in tumor therapy. LncRNA-miRNA axis can also affect other signaling networks in cancer such as PI3K/Akt, STAT3, Wnt/β-catenin and EZH2 among others. Notably, lncRNA/miRNA axis can be considered as a signature for diagnosis and prognosis in cancers.

miR-335-5p regulates the proliferation, migration and phenotypic switching of vascular smooth muscle cells in aortic dissection by directly regulating SP1

Uncontrolled proliferation, migration and phenotypic switching of vascular smooth muscle cells (VSMCs) are important steps in the development and progression of aortic dissection (AD). The function and potential mechanism of miR-335-5p in the pathogenesis of AD are explored in this study. Specifically, the biological function of miR-335-5p is explored in vitro through CCK-8, Transwell, immunofluorescence, EdU, wound-healing, RT-qPCR and western blotting assays. In addition, an AD model induced by angiotensin II is used to investigate the function of miR-335-5p in vivo. A dual-luciferase assay is performed to verify the targeting relationship between miR-335-5p and specificity protein 1 (SP1). Experiments involving the loss of SP1 function are performed to demonstrate the function of SP1 in the miR-335-5p-mediated regulation of human aortic-VSMCs (HA-VSMCs). AD tissues and platelet-derived growth factor BB (PDGF-BB)-stimulated HA-VSMCs show significant downregulation of miR-335-5p expression and upregulated SP1 expression. Overexpression of miR-335-5p effectively suppresses cell proliferation, migration and synthetic phenotype markers and enhances contractile phenotype markers induced by PDGF-BB treatment. Additionally, SP1 is identified as a target gene downstream of miR-335-5p, and its expression is negatively correlated with miR-335-5p in AD. Upregulation of SP1 partially reverses the inhibitory effect of miR-335-5p on HA-VSMCs, whereas the downregulation of SP1 has the opposite effect. Furthermore, Ad-miR-335-5p clearly suppresses aorta dilatation and vascular media degeneration in the AD model. Our results suggest that miR-335-5p inhibits HA-VSMC proliferation, migration and phenotypic switching by negatively regulating SP1, and indicate that miR-335-5p may be a potential therapeutic target in AD.

lncRNA XIST is associated with preeclampsia and mediates trophoblast cell invasion via miR-340-5p/KCNJ16 signaling pathway

BACKGROUND

Preeclampsia (PE) is a syndrome commonly occurring among the pregnant. Shallow trophoblast invasion is considered to be closely related to PE. Therefore, in trophoblast cells, we explored the potential mechanisms of lncRNA XIST in the modulation of trophoblast invasion and proliferation.

METHODS

GEO online analyzer was used to screen the abnormally expressed RNAs in placenta tissues from patients with severe PE and healthy controls. The prediction of target bindings was performed on TargetScan and starBase. Transfection was conducted to regulate the RNA expression levels in trophoblast cells, HTR-8/SVneo. RT-qPCR measured expression of lncRNA XIST, miR-340-5p and KCNJ16. The CCK-8 assay examined cell viability. Flow cytometer analyzed apoptosis and luciferase assay determined the luciferase activity. Transwell assays detected the invasion and western blot verified the changes in protein expression of MMP2, MMP9 and KCNJ16 in trophoblast cells.

RESULTS

lncRNA XIST expression was enhanced in PE patients. Upregulation of lncRNA XIST in HTR-8/SVneo cells inhibited the cell proliferation and invasion, and induced apoptosis. XIST upregulation inhibited MMP2 and MMP9 protein expression. lncRNA XIST/ KCNJ16 interplayed as ceRNAs of miR-340-5p. Specifically,miR-340-5p overexpression reversed the effect of XIST upregulation on the cell apoptosis, proliferation and invasive ability and the knockdown of KCNJ16 could add to the effect of miR-340-5p overexpression in HTR-8/SVneo.

CONCLUSION

lncRNA XIST was upregulated in PE. Upregulation of lncRNA XIST exerted the inhibitory effects on the proliferation and invasion of trophoblast cells through the interactions with miR-340-5p/KCNJ16, which suggests that the lncRNA XIST/miR-340-5p/KCNJ16 axis might play a role in PE.

Long noncoding RNA XIST: Mechanisms for X chromosome inactivation, roles in sex-biased diseases, and therapeutic opportunities

Sexual dimorphism has been reported in various human diseases including autoimmune diseases, neurological diseases, pulmonary arterial hypertension, and some types of cancers, although the underlying mechanisms remain poorly understood. The long noncoding RNA (lncRNA) X-inactive specific transcript (XIST) is involved in X chromosome inactivation (XCI) in female placental mammals, a process that ensures the balanced expression dosage of X-linked genes between sexes. XIST is abnormally expressed in many sex-biased diseases. In addition, escape from XIST-mediated XCI and skewed XCI also contribute to sex-biased diseases. Therefore, its expression or modification can be regarded as a biomarker for the diagnosis and prognosis of many sex-biased diseases. Genetic manipulation of XIST expression can inhibit the progression of some of these diseases in animal models, and therefore XIST has been proposed as a potential therapeutic target. In this manuscript, we summarize the current knowledge about the mechanisms for XIST-mediated XCI and the roles of XIST in sex-biased diseases, and discuss potential therapeutic strategies targeting XIST.

The lncRNAs at X Chromosome Inactivation Center: Not Just a Matter of Sex Dosage Compensation

Non-coding RNAs (ncRNAs) constitute the majority of the transcriptome, as the result of pervasive transcription of the mammalian genome. Different RNA species, such as lncRNAs, miRNAs, circRNA, mRNAs, engage in regulatory networks based on their reciprocal interactions, often in a competitive manner, in a way denominated “competing endogenous RNA (ceRNA) networks” (“ceRNET”): miRNAs and other ncRNAs modulate each other, since miRNAs can regulate the expression of lncRNAs, which in turn regulate miRNAs, titrating their availability and thus competing with the binding to other RNA targets. The unbalancing of any network component can derail the entire regulatory circuit acting as a driving force for human diseases, thus assigning “new” functions to “old” molecules. This is the case of XIST, the lncRNA characterized in the early 1990s and well known as the essential molecule for X chromosome inactivation in mammalian females, thus preventing an imbalance of X-linked gene expression between females and males. Currently, literature concerning XIST biology is becoming dominated by miRNA associations and they are also gaining prominence for other lncRNAs produced by the X-inactivation center. This review discusses the available literature to explore possible novel functions related to ceRNA activity of lncRNAs produced by the X-inactivation center, beyond their role in dosage compensation, with prospective implications for emerging gender-biased functions and pathological mechanisms.

Decreased exosome-delivered miR-486-5p is responsible for the peritoneal metastasis of gastric cancer cells by promoting EMT progress

Background

The present study aims to investigate the preliminary mechanism underlying the peritoneal metastasis of gastric cancer cells.

Methods

Exosomes from GC9811 cells (Con-Exo) and from GC9811-P cells (PM-Exo) were extracted by ultracentrifugation, which were identified with transmission electron microscopy (TEM) and nanoparticle trafficking analysis, as well as the expression of CD9, CD63, and CD81 detected by Western blot assay. α-SMA expression was determined by immunofluorescence assay and Western blot assay. The levels of Snail1, E-cadherin, and Actin-related protein 3 (ACTR3) were evaluated by Western blot assay. MiRNA array was performed on exosomes to screen the differentially expressed miRNAs. The expressions of miRNAs, SMAD2, CDK4, and ACTR3 were determined by QRT-PCR. The delivery of miR-486-5p was confirmed by laser confocal detection.

Results

Firstly, TEM, nanoparticle trafficking analysis, and Western blot assays were used to confirm the successful extraction of Con-Exo and PM-Exo. The incubation of Con-Exo and PM-Exo could decrease E-cadherin expression and increase of α-SMA respectively in HMrSV5 cells, with the increased proportion of fusiform cells. More significant changes were observed in PM-Exo-treated HMrSV5 cells. Secondary, compared to Con-Exo, miR-486-5p and miR-132-3p were found downregulated, and miR-132-5p was found upregulated in PM-Exo. The transfection of miR-486-5p and miR-132-3p was observed to suppress EMT, and the transfection of miR-132-3p was observed to induce EMT. Laser confocal detection confirmed the delivery of miR-486-5p from gastric cancer cells to HMrSV5 cells through exosomes. Lastly, the expression of Mothers against decapentaplegic homolog 2 (SMAD2), cyclin-dependent kinase 4 (CDK4), and ACTR3 was found to be downregulated via miR-486-5p.

Conclusion

Decreased delivery of miR-486-5p via exosomes might be responsible for the peritoneal metastasis of gastric cancer cells by promoting epithelial-mesenchymal transition progress.