Isoprenylated flavonoids from Morus nigra and their PPAR γ agonistic activities

Chemical Profile and Potential Application of Agri-food Waste Products for Counteracting Diabetes Induced Neuropathy in Rats

This study aimed to prepare defatted ethanol extract of Abelmoschus esculentus leaves, Morus nigra leaves and Punica granatum peel, to identify the chemical composition of these extracts and to explore their efficacy in counteracting diabetic neuropathy. LC-ESI-MS spectrometry was the hyphenated tool for component identification of these extracts. Behavioral, biochemical, and histopathological investigations were carried out after treatments of diabetic rats. The phenolic contents in the extracts are 16.38, 34.75 and 40.57 mg GAE/g extract regarding A. esculentus leaves, M. nigra leaves and P. granatum peel respectively. Chemodiversity of the phenolic contents was observed from the LC/Mass, where A. esculentus extract contained isoflavonoids and flavanones, M. nigra extract consisted of benzofurans, prenylated flavonoids, stilbenes, and xanthones, and P. granatum extract was rich in ellagitanins, condensed tannins, and anthocyanins. The extracts normalize of blood glucose levels, enhance the explorative behavior of the rats and their response time to thermal pain, restore the oxidant/antioxidant balance, attenuate inflammation, augment brain monoamines levels and modulate MAO-A and Ache enzyme activity. Furthermore, they recovered brain histopathological alterations. Conclusively, this study offers experimental evidence for the neuroprotective impact of studied defatted ethanol extracts against diabetic neuropathy via their hypoglycemic effect, antioxidant activity, and anti-inflammatory potential.

Black Mulberry (Morus nigra L.): A Review of Attributes as an Anticancer Agent to Encourage Pharmaceutical Development

Recent considerations of natural sources as potential anticancer agents have arisen due to the origins of numerous drugs commonly used in chemotherapy. Plant-based drugs, in particular, have attracted attention for offering the advantage of low adverse effects. Among these, the black mulberry plant (Morus nigra L.) stands out as a natural source of polyphenols, widely used to treat metabolic dysfunctions and confer benefits on human health. This study explores the potential of this plant as an anticancer agent, examining its effectiveness based on the type of application of the plant extracts or isolated substances, extraction methods, and its potential biological effects on cancer cells. Consequently, this study contributes to a better understanding of the distribution of phytochemicals in M. nigra and their applications in the context of cancer field. Among the compounds found in black mulberry are flavonoids, chlorogenic acid, cryptochlorogenic acid, and protocatechuic acid, along with cyanidin-3-O-glucoside as the main anthocyanin on the fruit. The phytochemicals derived from M. nigra exhibit antinociceptive and antimicrobial activities, while also showing protective effects, such as antioxidant properties that underline their potential as anticancer agents. The black mulberry's roots, stem bark, pulp, and leaves are particularly rich sources of anti-inflammatory compounds. Ethanol and methanol extraction methods appear to be the most effective in cancer management, offering compounds that facilitate the integration of apoptosis induction, cell growth inhibition, and cytotoxicity modulation. These results collectively represent the salient biological attributes that positioned black mulberry as a promising anticancer agent. Therefore, these findings highlight the multifaceted potential of M. nigra as an anticancer agent, making a compelling case for further research to advance prospects in the medical field.

Structures, activities, and putative biosynthetic pathways of characteristic polyphenolic compounds from Morus plants: A review

Morus plants played a pivotal role in ancient Chinese sericulture and silk production, which served as critical components of economy and culture. Besides, many parts of mulberry trees, including roots, leaves, stems, and fruits, hold various medicinal value, and have been utilized in traditional medicine for thousands of years. The chemical composition of mulberry has been reported in many literatures, while the characteristic compounds have not been systematically summarized. In this review, we focused on the polyphenolic compounds in mulberry, including flavonoids, 2-arylbenzofurans, and Diels-Alder (D-A) adducts, and summarized their structural features, structure-activity relationships, and potential biosynthetic pathways. The results revealed a characteristic class of 2'-hydroxylated flavonoids and stilbenes which played an important role in the biosynthesis of downstream 2-arylbenzofurans and D-A adducts in mulberry but had been overlooked by most studies. The prenylated modifications of different compounds were also discussed and their function as precursors of D-A adducts was emphasized. We also describe the effects of different modifications on biological activities. Besides, the chemical composition of Morus was most similar to that of Artocarpus in the Moraceae family in that they had almost identical characteristic compounds. Finally, a putative total biosynthetic pathway of D-A adducts in mulberry was proposed based on structure derivation and combination of verified reactions. This review contributes to the understanding of the biological activity and biosynthesis of the characteristic components of Morus plants.

Chemistry, bioactivities, structure-activity relationship, biosynthesis and metabolism of prenylated flavonoids in Moraceae plants

Plants from Moraceae are globally popular as they represent a valuable resource with wide applications in food, health-care products, and other fields. Prenylated flavonoids are important active components in Moraceae. These compounds share a flavonoid skeleton with prenylated side chain, mostly in the form of single or multiple isoprenyl substituents and benzodimethylfuran structures. So far, nearly 400 prenylated flavonoids have been found in Moraceae, especially a large number of Diels-Alder adducts, which are characteristic components of this family. Due to their distinctive structures, diverse pharmacological properties and interesting synthesis processes, these compounds have attracted considerable attention from scientists. Herein, we review the advances in the structural characteristics, bioactivities, structure-activity relationships, biosynthesis strategies and in vivo metabolism of prenylated flavonoids in Moraceae plants, aiming at strengthening research efforts and utilization toward the great untapped potential of these unique constituents in human health.

Metabolites of endophytic fungi isolated from leaves of Bauhinia variegata exhibit antioxidant activity and agonist activity on peroxisome proliferator-activated receptors α, β/δ and γ

Diabetes mellitus is a metabolic disorder that affects millions of people worldwide and is linked to oxidative stress and inflammation. Thiazolidinediones (TZD) improve insulin sensitization and glucose homeostasis mediated by the activation of peroxisome proliferator-activated receptors γ (PPARγ) in patients with type 2 diabetes. However, their use is associated with severe adverse effects such as loss of bone mass, retention of body fluids, liver and heart problems, and increased risk of bladder cancer. Partial PPARγ agonists can promote the beneficial effects of thiazolidinediones with fewer adverse effects. Endophytic fungi colonize plant tissues and have a particularly active metabolism caused by the interaction with them, which leads to the production of natural products with significant biological effects that may be like that of the colonized plant. Here, we identify seven endophytic fungi isolated from Bauhinia variegata leaves that have antioxidant activities. Also, one of the extracts presented pan-agonist activity on PPAR, and another showed activity in PPARα and PPARβ/δ. A better understanding of this relationship could help to comprehend the mechanism of action of antioxidants in treating diabetes and its complications. Moreover, compounds with these capabilities to reduce oxidative stress and activate the receptor that promotes glucose homeostasis are promising candidates in treatment of diabetes.

Hydroethanolic Extract of Morus nigra L. Leaves: A Dual PPAR-α/γ Agonist with Anti-Inflammatory Properties in Lipopolysaccharide-Stimulated RAW 264.7

Inhibition of systemic inflammation has been a beneficial strategy in treating several non-communicable diseases, which represent one of the major causes of mortality in the world. The Peroxisome Proliferator-Activated Receptors (PPAR) are interesting pharmacological targets, since they can act both through the metabolic and anti-inflammatory pathways. Morus nigra L. has flavonoids in its chemical composition with recognized anti-oxidant activity and often associated with anti-inflammatory activity. Therefore, this study aimed to evaluate the hydroethanolic extract of M. nigra leaves' ability to activate PPAR and promote anti-inflammatory effects in lipopolysaccharide (LPS)-stimulated murine macrophage cells. The leaf extract was prepared by cold maceration, and the chemical profile was obtained by HPLC-DAD. Activation of PPAR α and γ was evaluated by the luciferase reporter assay. The anti-inflammatory activity was assessed by measuring the reactive oxygen species (ROS), nitric oxide (NO), and Tumor Necrosis Factor-α (TNF-α) in RAW 264.7 cells after stimulation with LPS from Escherichia coli. The HPLC-DAD analysis identified two major compounds: rutin and isoquercitrin. The extract showed agonist activity for the two types of PPAR, α and γ, although its major compounds, rutin and isoquercitrin, did not significantly activate the receptors. In addition, the extract significantly reduced the production of ROS, NO, and TNF-α. Treatment with the specific PPAR-α antagonist, GW 6471, was able to partially block the anti-inflammatory effect caused by the extract.

Prenylated flavonoids from Morus nigra and their insulin sensitizing activity

Six undescribed prenylated flavonoids, nigragenons H-M, and four known compounds, were isolated from Morus nigra L. Their structures were elucidated through extensive analysis of spectroscopic data, and their absolute configurations were established by time-dependent density functional theory electronic circular dichroism (TDDFT ECD) calculation. The insulin sensitizing activities of all compounds were investigated using insulin-resistant 3T3-L1 adipocytes. At a high concentration (30 μM), all compounds except nigragenon I enhanced insulin-stimulated glucose uptake in insulin-resistant 3T3-L1 adipocytes. Furthermore, nigragenons J-L and the promoted adiponectin secretion in the model cells. Among them, nigragenon L showed the most potent effect at a low concentration of 10 μM, which was comparable to that of rosiglitazone at a concentration of 1 μM. Furthermore, using the Lantha Screen™ TR-FRET assay, nigragenon L was confirmed to be the ligand of PPARγ, showing potent binding affinity toward PPARγ with an IC₅₀ value of 2.8 μM.

Ameliorating Effect of the Total Flavonoids of Morus nigra L. on Prediabetic Mice Based on Regulation of Inflammation and Insulin Sensitization

Prediabetes is a critical stage characterized by insulin resistance. Morus nigra L., an edible plant, is widely used in food and nutritive supplements and exhibits various pharmacological activities; however, its therapeutic effects and mechanisms on prediabetes have rarely been reported. In this research, the major components of total flavonoids of M. nigra L. (TFM) were identified, and TFM treatment was found to reduce prediabetes progressing to type 2 diabetes mellitus (T2DM) from 93.75 to 18.75%. The microbiota and next-generation sequencing combined with western blotting in vivo and in vitro demonstrated that TFM and its components ameliorated insulin resistance mediated by the suppressor of cytokine signaling and protein tyrosine phosphatase 1B, which benefited by maintaining intestinal homeostasis and restraining plasma levels of inflammatory factors. This study confirmed the T2DM prevention effect of TFM and revealed the underlying mechanism, setting the stage for the design of functional foods for diabetes prevention.

Protective Effect of Galangin Methylation Modification Based on Cell Imaging on Inflammatory Lung Injury and Its Molecular Mechanism

Background

Recently, inflammation has become a major threat to human health. Studies have confirmed that some Chinese traditional medicine ingredients may effectively interfere with the expression of inflammatory mediators through epigenetic modification, showing a great potential of the application.

Objective

To investigate the role of the PPAR/DNMT3A pathway in the reversal of galangin-mediated inflammatory lung injury, promote the development of new anti-inflammatory drugs, reduce the side effects of chemical synthetic drugs on the body, and prove the effectiveness and safety of galangin in inhibiting inflammatory response and injury.

Methods

120 rats were randomly divided into 6 groups: (Group 1) LPS group; (Group 2) LPS + galangin group; (Group 3) LPS + galangin +  GW9662 group; (Group 4) LPS + galangin + DNMT3A siRNA group; (Group 5) LPS + galangin + siRNA negative group; (Group 6) control group. The model of inflammatory lung injury was established by intrathecal instillation of LPS in the first five groups and NS in the control group. SD survival rate was recorded every 24 hours after modeling, lasting for 168 hours. The lung tissues were taken 168 hours after the establishment of the model. The pathological morphology of lung tissue was observed after the staining under the light microscope, and the lung dry/wet weight ratio was calculated after drying. After NS was perfused into lung tissue, the lavage fluid was collected and the levels of IL-6 and TNF-a were measured by ELISA. The contents of PPAR, DNMT3A, phosphorylated p65, and ERK in monocytes were detected by the WB method, and the binding contents of p65 and AP-1 in the promoter regions of IL-6 and TNF-a genes were detected by the Chip-qPCR method.

Results

Intraperitoneal injection of galangin could inhibit the synthesis of alveolar inflammatory factors (TFs) in the SD model of lung injury induced by LPS, reduce the degree of pathological injury of lung tissue, and improve the survival rate of the SD model. GW9662 can completely reverse the protective effect, while DNMT3A interference can only partially block its protective effect. In addition, galangin could significantly inhibit the LPS-induced expression of p65 and AP-1 in alveolar monocytes and their binding content in the promoter region of inflammatory genes by activating PPAR/DNMT3A pathway. GW9662 could completely reverse the inhibitory effect of galangin. DNMT3A interference could restore the binding content of transcription factors at the promoter of the inflammatory gene but had no significant effect on its synthesis.

Conclusion

Galangin can interfere with the binding of transcription factors to inflammatory gene promoters through the methylation modification induced by PPAR/DNMT3A pathway, so as to inhibit the synthesis of inflammatory molecules and reverse inflammatory lung injury.

Natural Enantiomers: Occurrence, Biogenesis and Biological Properties

The knowledge that natural products (NPs) are potent and selective modulators of important biomacromolecules (e.g., DNA and proteins) has inspired some of the world's most successful pharmaceuticals and agrochemicals. Notwithstanding these successes and despite a growing number of reports on naturally occurring pairs of enantiomers, this area of NP science still remains largely unexplored, consistent with the adage "If you don't seek, you don't find". Statistically, a rapidly growing number of enantiomeric NPs have been reported in the last several years. The current review provides a comprehensive overview of recent records on natural enantiomers, with the aim of advancing awareness and providing a better understanding of the chemical diversity and biogenetic context, as well as the biological properties and therapeutic (drug discovery) potential, of enantiomeric NPs.

Clinical efficacy of capsules containing standardized extract of Bauhinia forficata Link (pata-de-vaca) as adjuvant treatment in type 2 diabetes patients: A randomized, double blind clinical trial

ETHNOPHARMACOLOGICAL RELEVANCE

Bauhinia forficata Link, is a Brazilian native plant and popularly known as pata-de-vaca ("paw-of-cow"). The tea prepared with their leaves has been extensively used in the Brazilian traditional practices for the diabetes treatment. The aim of the present study was to investigate the effect of capsules containing granules of a standardized extract of B. forficata leaves as adjuvant treatment on the glycemic control of patients with type-2 diabetes melitus.

MATERIALS AND METHODS

A double-blind, randomized clinical trial using capsules containing granules prepared by wet granulation of a standardized extract from B. forficata leaves as adjuvant treatment, was conducted. 92 patients aged 18-75 years from an outpatient clinic with type-2 diabetes were randomly assigned by a simple randomization scheme, in a 1:1 ratio to receive capsules of B. forficata or placebo for four months. The capsules used contain 300 mg of standardized extract from B. forficata leaves, yielding 2% of total flavonoid content per capsule. Primary outcome was glycated hemoglobin levels and fasting plasma glucose at 4 months. Possible harms were also determined.

RESULTS

The findings showed that at 4 months, the mean fasting plasma glucose levels and glycated hemoglobin were both significantly lower in the B. forficata group than in the placebo group.

CONCLUSION

The present study suggests that the adjunctive use of capsules containing standardized extract of B. forficata can add to regular oral anti-diabetics in the metabolic and inflammatory control of type-2 diabetes patients.

Do Uncommon Plant Phenolic Compounds Have Uncommon Properties? A Mini Review on Novel Flavonoids

Unique plants and their properties, once considered synonymous to medicine, remain a potent source for new compounds in modern science. Plant polyphenols and natural products continue to be investigated for effective treatments for the most persistent of human ailments. In this review, fifty novel plant phenolic compounds have been compiled and briefly described from the previous five years. Select compounds and notable plant species from genus Morinda and Sophora are further expanded on. Traditional medicine plants often contain rich and diverse mixtures of flavonoids, from which rare compounds should receive attention. The bioactivity of crude plant extracts, purified compounds and mixtures can differ greatly, requiring that these interactions and mechanisms of action be investigated in greater detail. Novel applications of uncommon natural products, namely mimosine and juglone, are explored within this review. The 2019 coronavirus pandemic has resulted in abrupt spike of related scientific publications: speculation is made regarding plant natural products and future of antiviral drug discovery.

Development of mode of action networks related to the potential role of PPARγ in respiratory diseases

The peroxisome proliferator-activated receptor γ (PPARγ) is a key transcription factor, operating at the intercept of metabolic control and immunomodulation. It is ubiquitously expressed in multiple tissues and organs, including lungs. There is a growing body of information supporting the role of PPARγ signalling in respiratory diseases. The aim of the present study was to develop mode of action (MoA) networks reflecting the relationships between PPARγ signalling and the progression/alleviation of a spectrum of lung pathologies. Data mining was performed using the resources of the NIH PubMed and PubChem information systems. By linking available data on pathological/therapeutic effects of PPARγ modulation, knowledge-based MoA networking at different levels of biological organization (molecular, cellular, tissue, organ, and system) was performed. Multiple MoA networks were developed to relate PPARγ modulation to the progress or the alleviation of pulmonary disorders, triggered by diverse pathogenic, genetic, chemical, or mechanical factors. Pharmacological targeting of PPARγ signalling was discussed with regard to ligand- and cell type-specific effects in the context of distinct disease inductor- and disease stage-dependent patterns. The proposed MoA networking analysis allows for a better understanding of the potential role of PPARγ modulation in lung pathologies. It presents a mechanistically justified basis for further computational, experimental, and clinical monitoring studies on the dynamic control of PPARγ signalling in respiratory diseases.

Flavonoids: structure-function and mechanisms of action and opportunities for drug development

Flavonoids are polyphenolic phytochemicals produced in fruits, nuts and vegetables and dietary consumption of these structurally diverse compounds is associated with multiple health benefits including increased lifespan, decreased cardiovascular problems and low rates of metabolic diseases. Preclinical studies with individual flavonoids demonstrate that these compounds exhibit anti-inflammatory and anticancer activities and they enhance the immune system. Their effectiveness in both chemoprevention and chemotherapy is associated with their targeting of multiple genes/pathways including nuclear receptors, the aryl hydrocarbon receptor (AhR), kinases, receptor tyrosine kinases and G protein-coupled receptors. However, despite the remarkable preclinical activities of flavonoids, their clinical applications have been limited and this is due, in part, to problems in drug delivery and poor bioavailability and these problems are being addressed. Further improvements that will expand clinical applications of flavonoids include mechanism-based precision medicine approaches which will identify critical mechanisms of action of individual flavonoids with optimal activities that can be used in combination therapies.

Therapeutic potential of PPARγ natural agonists in liver diseases

Peroxisome proliferator‐activated receptor gamma (PPARγ) is a vital subtype of the PPAR family. The biological functions are complex and diverse. PPARγ plays a significant role in protecting the liver from inflammation, oxidation, fibrosis, fatty liver and tumours. Natural products are a promising pool for drug discovery, and enormous research effort has been invested in exploring the PPARγ‐activating potential of natural products. In this manuscript, we will review the research progress of PPARγ agonists from natural products in recent years and probe into the application potential and prospects of PPARγ natural agonists in the therapy of various liver diseases, including inflammation, hepatic fibrosis, non‐alcoholic fatty liver and liver cancer.

Randomized double-blind placebo-controlled trial of the effect of Morus nigra L. (black mulberry) leaf powder on symptoms and quality of life among climacteric women

OBJECTIVE

To test the efficacy of Morus nigra L. (MN) leaf powder for treating climacteric symptoms by comparison with hormone therapy (HT) and placebo.

METHODS

A randomized controlled trial among 62 climacteric women attending Hospital of the Federal University of Maranhão, Brazil. Women were divided into MN, HT, and placebo groups, and received 250 mg of MN leaf powder, 1 mg of estradiol, or placebo for 60 days. Primary outcomes were the Blatt-Kupperman index (BKI) for climacteric symptoms and SF-36 health questionnaire scores.

RESULTS

Baseline sociodemographic variables, BKI scores, symptoms, and SF-36 domains did not differ among the groups. There was a reduction in mean BKI in the MN (17.5 vs 9.7, P<0.001), HT (15.4 vs 8.6, P=0.001), and placebo (16.1 vs 12.4, P=0.040) groups. Analysis of quality of life (QoL) showed that functional capacity (P=0.006), vitality (P=0.031), mental health (P=0.017), and social aspect (P<0.01) improved after treatment in the MN group. The HT group showed improvement in emotional limitation (P=0.040), and the placebo group showed better functional capacity (P=0.030) after treatment.

CONCLUSIONS

Climacteric symptoms and QoL improved after administration of 250 mg of MN leaf powder for 60 days, similar to the effects of HT. The trial is registered in the Brazilian Registry of Clinical Trials (REBEC) under registration number RBR-9t4xxk.

Chiral separation, absolute configuration, and bioactivity of two pairs of flavonoid enantiomers from Morus nigra

An undescribed isoprenylated flavonol racemate, nigranol C, with an unprecedented 7/6/6 ring system, was isolated from the twigs of Morus nigra L. The structure was assigned through a comprehensive analysis of HRMS, IR, and NMR data. Chiral separation of nigranol C was successfully carried out to yield a pair of enantiomers, nigranol C-a and nigranol C-b, whose absolute configurations were determined by ECD calculation. A plausible biogenetic pathway for nigranol C was proposed. A previously isolated sanggenon-type flavonone racemate, nigragenon E, was also well resolved by chiral HPLC to offer another pair of enantiomers, nigragenon E-a and nigragenon E-b, whose stereo configurations were determined by ECD data. All of the isolated compounds showed prominent α-glucosidase inhibitory activities with IC₅₀ values ranging from 9.79 to 30.21 μM, while only the sanggenon-type flavonones exhibited tyrosinase inhibitory effects comparable to that of the positive control, kojic acid, the IC₅₀ value of which was 27.14 μM. In addition, it was found that the stereo configurations of these compounds seemed to play a negligible role in their inhibitory activities towards the two enzymes.

Pharmacological Properties of Morus nigra L. (Black Mulberry) as A Promising Nutraceutical Resource

Mulberry plants belonging to the Moraceae family have been grown for the purpose of being the nutrient source for silk worm and raw materials for the preparation of jams, marmalades, vinegars, juices, wines, and cosmetics. Morus nigra L. (black mulberry) is native to Southwestern Asia, and it has been used as a traditional herbal medicine for animals and humans. In this article, recent research progress on various biological and pharmacological properties of extracts, fractions, and isolated active constituents from different parts of M. nigra are reviewed. M. nigra exhibited a wide-spectrum of biological and pharmacological therapeutic effects including antinociceptive, anti-inflammatory, antimicrobial, anti-melanogenic, antidiabetic, anti-obesity, anti-hyperlipidemic, and anticancer activities. M. nigra also showed protective effects against various human organs and systems, mainly based on its antioxidant capacity. These findings strongly suggest that M. nigra can be used as a promising nutraceutical resource to control and prevent various chronic diseases.

Metabolic effects of mulberry branch bark powder on diabetic mice based on GC-MS metabolomics approach

BACKGROUND

Mulberry (Morus multicaulis) branch bark powder have showed effective hypoglycemic activity in our previous research. This study aims to explore the mechanism of protect effect on diabetes mice of mulberry branch bark as food supplement based on non-targeted GC-MS metabolomics' platform.

METHODS

Animal model of double diabetes was established with high fat diet and Streptozotocin injection. Mice were fed with mulberry branch bark powder (MBBP) for five weeks to study its therapeutic effect. The metabolite feature of diabetes model and treatment group mice were characterized using a gas chromatography-mass spectrometry-based metabolomics, complemented with the biochemical evaluation, histological inspection, immunohistochemistry observations and enzyme protein detection.

RESULTS

A panel of endogenous metabolites were revealed that are relevant to disturbed metabolic processes among groups. The serum metabolic profiles were significantly different between the model group and treatment group. The manner of MBBP treatment showed to be significantly dose dependent and 20% MBBP treatment gain a relatively greater benefit than others. The metabolic disorders in model group include enhanced activation of the sorbitol pathway and galactose metabolite, increased activities of gluconeogenesis, fatty acid oxidation, proteins catabolism and attenuated activities of pentose phosphate pathway, glycolysis and aerobic oxidation pathways, internal synthesis of cholesterol, inositol production. MBBP treatment ameliorate these abnormal metabolize as revealed by differential metabolites comparing with that of model mice, such as decreasing the accumulation of ketone body, enhancing NADPH biosynthesis, partially reversing oxidative stress and energy metabolism disturbance.

CONCLUSIONS

Mulberry branch bark had a re-balancing effect on the disturbed metabolic pathways in the diabetic mice. Based on the metabolic pathways network, oral administration of MBBP could ameliorate the hyperglycemia and hyperlipidemia symptoms in a global scale and restore the abnormal metabolic state to a near normal level in a dose dependent pattern.

SLC6A1-miR133a-CDX2 loop regulates SK-OV-3 ovarian cancer cell proliferation, migration and invasion

The present study assessed the expression of solute carrier 6 member 1 (SLC6A1) in ovarian cancer (OC) tissues and evaluated the effect of silencing SLC6A1 or caudal type homeobox 2 (CDX2) on the proliferation, migration, and invasion of SK-OV-3 OC cells. The levels of caudal type homeobox 2 (CDX2) and SLC6A1 mRNA were also examined in OC SK-OV-3, OVCAR3 and A2780 cell lines. The mRNA levels of CDX2 and SLC6A1 in SK-OV-3 OC cells were assessed following transection with microRNA (miR) 133a mimics; the mRNA and protein levels of SLC6A1 were determined following the silencing of CDX2, and the mRNA expression of CDX2 was gauged following the silencing of SLC6A1. A luciferase reporter assay was performed to assess the effect of miR133a on the CDX2 and SLC6A1 3′-untranslated regions (3′UTRs). The proliferation, migration and invasion rate of SK-OV-3 cells were then examined following the silencing of CDX2 or SLC6A1. The expression of SLC6A1 was increased in OC compared with adjacent tissue. The expression of CDX2 and SLC6A1 in SK-OV-3 and OVCAR3 cells was increased compared with A2780 cells (P<0.05). The level of CDX2 and SLC6A1 mRNA in SK-OV-3 cells decreased when the cells were transected with the miR133a mimics, compared with a negative control (P<0.05). Transfection with the miR133a mimics significantly reduced the luciferase activity of reporter plasmids with the SLC6A1 or CDX2 3′UTRs (P<0.05). The mRNA level of CDX2 was decreased subsequent to the silencing of SLC6A1; the mRNA and protein level of SLC6A1 were decreased when CDX2 was silenced (P<0.05). The proliferation, migration, and invasion of SK-OV-3 cells were significantly reduced following the silencing of CDX2 or SLC6A1 (P<0.05). CDX2 may therefore be inferred to promote the proliferation, migration and invasion in SK-OV-3 OC cells, acting as a competing endogenous RNA.