Clinical and genetic evaluations of Zimmermann-Laband syndrome with gingival fibromatosis: a rare case report.

Zimmermann-Laband Syndrome (ZLS; MIM 135500) is a rare genetic disorder with the main clinical manifestations of gingival fibromatosis and finger/toe nail hypoplasia. KCNH1 (potassium channel, voltage-gated, subfamily H, member-1), KCNN3 (potassium channel, voltage-gated, subfamily H, member-3) and ATP6V1B2 (ATPase H+ transporting V1 subunit B2) genes are considered causative genes for ZLS. However, there are limited reports about the diverse clinical presentation and genetic heterogeneity. Reporting more information on phenotype-genotype correlation and the treatment of ZLS is necessary. This case reported a 2-year-old patient with gingival enlargement that failure of eruption of the deciduous teeth and severe hypoplasia of nails. Based on a systemic examination and a review of the relevant literature, we made an initial clinical diagnosis of ZLS. A novel pathogenic variant in the KCNH1 gene was identified using whole-exome sequencing to substantiate our preliminary diagnosis. The histopathological results were consistent with gingival fibromatosis. Gingivectomy and gingivoplasty were performed under general anesthesia. After surgery, the gingival appearance improved significantly, and the masticatory function of the teeth was restored. After 2-year follow-up, the gingival showed slightly hyperplasia. Systemic examination and gene sequencing firstly contribute to provide information for an early diagnosis for ZLS, then timely removal of the hyperplastic gingival facilitates the establishment of a normal occlusal relationship and improves oral aesthetics.

Effects of Marine Natural Products on Liver Diseases.

The prevention and treatment of liver disease, a class of disease that seriously threatens human health, has always been a hot topic of medical research. In recent years, with the in-depth exploration of marine resources, marine natural products have shown great potential and value in the field of liver disease treatment. Compounds extracted and isolated from marine natural products have a variety of biological activities such as significant antiviral properties, showing potential in the management of alcoholic liver disease (ALD) and non-alcoholic fatty liver disease (NAFLD), protection of the liver from fibrosis, protection from liver injury and inhibition of the growth of hepatocellular carcinoma (HCC). This paper summarizes the progress of research on marine natural products for the treatment of liver diseases in the past decade, including the structural types of active substances from different natural products and the mechanisms underlying the modulation of different liver diseases and reviews their future prospects.

Functional Food Chemical Ingredient Strategies for Non-alcoholic Fatty Liver Disease (NAFLD) and Hepatic Fibrosis: Chemical Properties, Health Benefits, Action, and Application.

PURPOSE OF REVIEW: The liver is an important digestive gland in the body. Lifestyle and dietary habits are increasingly damaging our liver, leading to various diseases and health problems. Non-alcoholic fatty liver disease (NAFLD) has become one of the most serious liver disease problems in the world. Diet is one of the important factors in maintaining liver health. Functional foods and their components have been identified as novel sources of potential preventive agents in the prevention and treatment of liver disease in daily life. However, the effects of functional components derived from small molecules in food on different types of liver diseases have not been systematically summarized. RECENT FINDINGS: The components and related mechanisms in functional foods play a significant role in the development and progression of NAFLD and liver fibrosis. A variety of structural components are found to treat and prevent NAFLD and liver fibrosis through different mechanisms, including flavonoids, alkaloids, polyphenols, polysaccharides, unsaturated fatty acids, and peptides. On the other hand, the relevant mechanisms include oxidative stress, inflammation, and immune regulation, and a large number of literature studies have confirmed a close relationship between the mechanisms. The purpose of this article is to examine the current literature related to functional foods and functional components used for the treatment and protection against NAFLD and hepatic fibrosis, focusing on chemical properties, health benefits, mechanisms of action, and application in vitro and in vivo. The roles of different components in the biological processes of NAFLD and liver fibrosis were also discussed.

Changes in nitrogen metabolism of phosphorus-starved bloom-forming cyanobacterium Microcystis aeruginosa: Implications for nutrient management.

The surplus of nitrogen plays a key role in the maintenance of cyanobacterial bloom when phosphorus has already been limited. However, the interplay between high nitrogen and low phosphorus conditions is not fully understood. Nitrogen metabolism is critical for the metabolism of cyanobacteria. Transcriptomic analysis in the present study suggested that nitrogen metabolism and ribosome biogenesis were the two most significantly changed pathways in long-term phosphorus-starved bloom-forming cyanobacteria Microcystis aeruginosa FACHB-905. Notably, the primary glutamine synthetase/glutamate synthase cycle, crucial for nitrogen metabolism, was significantly downregulated. Concurrently, nitrogen uptake showed a marked decrease due to reduced expression of nitrogen source transporters. The content of intracellular nitrogen reservoir phycocyanin also showed a drastic decrease upon phosphorus starvation. Our study demonstrated that long-term phosphorus-starved cells also suffered from nitrogen deficiency because of the reduction in nitrogen assimilation, which might be limited by the reduced ribosome biogenesis and the shortage of adenosine triphosphate. External nitrogen supply will not change the transcriptions of nitrogen metabolism-related genes significantly like that under phosphorus-rich conditions, but still help to maintain the survival of phosphorus-starved cells. The study deepens our understanding about the survival strategies of Microcystis cells under phosphorus starvation and the mutual dependence between nitrogen and phosphorus, which would provide valuable information for nutrient management in the eutrophicated water body.

The Incidence and Risk Factors of Acute Myocardial Infarction Among Patients with Gastrointestinal bleeding: A Retrospective Study.

Purpose: Patients with gastrointestinal bleeding (GIB) and acute myocardial infarction (AMI) have higher mortality than that with either GIB or AMI alone. The aims of this study were to determine the incidence and risk factors of AMI in patients with GIB. Patients and Methods: From January 2015 to January 2018, we retrospectively studied 1287 patients with GIB in Renmin Hospital of Wuhan University. Various demographic, laboratory and outcome data were reviewed by charts. Results: Thirty-seven patients had AMI and were placed in AMI group and the rest 1250 patients were in non-AMI group. Patients with AMI were more likely to be older than 70 years, have hypertension, coronary heart disease, chronic kidney disease, and have the recent history of taking aspirin before admission. The ROC curve of hemoglobin (HB) on admission showed area under curve was 0.762, the optimal cut-off value is 76.5g/L. Logistic regression analysis showed that age ≥ 70 years old, coronary heart disease and HB < 76.5g/L on admission were independent risk factors of AMI in patients with GIB. The mortality of patients during hospitalization in AMI group and in non-AMI group were 45.95% and 5.48%, respectively. Patients who displayed a history of liver disease and HB < 76.5g/L on admission had a higher death rate. Conclusion: GIB increased the risk of subsequent AMI, especially in patients over 70 years old, with history of coronary heart disease and HB < 76.5g/L on admission. Patients with GIB and AMI who had history of liver disease and HB < 76.5g/L on admission had a higher mortality rate. Clinicians should identify the high-risk patients of AMI among the GIB population early and prevent AMI.

Amyloid-mediated remineralization for tooth hypoplasia of cleidocranial dysplasia.

Introduction: Cleidocranial dysplasia (CCD) is an autosomal-dominant, heritable skeletal and dental disease, involving hypoplastic clavicles, defective ossification of the anterior fontanelle, dentin and enamel hypoplasia, and supernumerary teeth, which can seriously affect the oral and mental health of patients. Amyloid-like protein aggregation, which is established by lysozyme conjugated with polyethylene glycol (Lyso-PEG), forms a mineralized nanofilm layer on a healthy enamel surface. However, whether it can form a remineralization layer in dental tissues from CCD remains unclear. Methods: This study evaluated deciduous teeth from healthy individuals and a patient with CCD. Because pulp and dentin are functionally closely related, stem cells from human exfoliated deciduous teeth (SHED) from CCD patients and healthy individuals were collected to compare their biological properties. Results: The results found that deciduous teeth from patients with CCD exhibited dentin hypoplasia. In addition, the proliferative ability and osteogenic potential of SHED from patients with CCD were lower than those of control individuals. Finally, Lyso-PEG was applied to dentin from the CCD and control groups, showing a similar remineralization-induced effect on the dentin surfaces of the two groups. Conclusion: These results extend our understanding of the dentin and SHED of patients with CCD, exhibiting good caries-preventive capacity and good biocompatibility of Lyso-PEG, thus providing a novel dental therapy for CCD and patients with tooth hypoplasia.

The Effects of Multi-Donor Fecal Microbiota Transplantation Capsules Combined with Thalidomide on Hormone-Dependent Ulcerative Colitis.

Objective: This study aimed to assess the effects of multi-donor fecal microbiota transplantation (FMT) capsules combined with thalidomide on hormone-dependent ulcerative colitis (UC). Methods: A total of 59 patients with steroid-dependent UC treated at the Gastroenterology Department of the First Affiliated Hospital of Xinxiang Medical University between January 2017 and January 2019 were enrolled in this study. Using a random number table, the patients were divided into two groups: a group treated with FMT capsules (the FMT group) and a group treated with FMT capsules and thalidomide (the FMT+S group). Multi-donor FMT capsules were prepared, and all subjects and stool donors followed the FMT pathway for FMT transplantation. Each patient's Mayo score, C-reactive protein (CRP) level, and level of fecal calprotectin before FMT treatment and at week 1 and week 13 after treatment were recorded. All patients were followed up for 15 weeks. Results: A total of 56.7% of the patients (34/59) achieved a therapeutic response at the end of the research period. Compared with the FMT group, the FMT+S group had better clinical benefit (P < 0.05). In the comparison of efficacy at week 1 and week 13 after treatment, the Mayo scores, calprotectin levels, and CRP indexes in the FMT+S group were better than those in the FMT group (P < 0.05). There were no serious adverse events in the treatment process or during follow-up. Conclusion: A combination of FMT capsules and thalidomide provides a treatment choice for patients with hormone-dependent UC, and it can be used as an adjuvant therapy. However, large-scale, multi-center, and prospective trials are required to further verify the reliability of this treatment.

Amyloid-Mediated Remineralization in Pit and Fissure for Caries Preventive Therapy.

The pits and fissures of teeth have high caries susceptibility, and sealing these areas is considered as an effective method to prevent caries. However, long-term caries prophylaxis cannot be maintained because of the negative effects derived from the technical sensitivity and disadvantages of sealing materials. Herein, a new strategy is proposed to occlude fossae by amyloid-mediated biomimetic remineralization. In contrast to conventional inward blocking from the outside of fossae, amyloid-mediated biomimetic mineralization delivers an amyloid-like protein nanofilm into the deepest zone of the fossae and induces the formation of remineralized enamel inside. Such assembly from lysozyme conjugated with poly (ethylene glycol) enriches the interface with strongly bonded ionsand directs in situ nucleation to achieve enamel epitaxial growth. Not only is the structure of the enamel-like crystalline hydroxyapatite layer but also its mechanical stability is similar to that of natural enamel. Furthermore, the layer shows good biocompatibility and antibacterial properties. On the basis of the findings, it is demonstrated that amyloid-like protein aggregation may provide an enamel remineralization strategy to modify the current clinically available methods of pit and fissure sealing and shows great promise in preventing caries.

Odontogenesis-related developmental microenvironment facilitates deciduous dental pulp stem cell aggregates to revitalize an avulsed tooth.

Harnessing developmental processes for tissue engineering represents a promising yet challenging approach to regenerative medicine. Tooth avulsion is among the most serious traumatic dental injuries, whereas functional tooth regeneration remains uncertain. Here, we established a strategy using decellularized tooth matrix (DTM) combined with human dental pulp stem cell (hDPSC) aggregates to simulate an odontogenesis-related developmental microenvironment. The bioengineered teeth reconstructed by this strategy regenerated three-dimensional pulp and periodontal tissues equipped with vasculature and innervation in a preclinical pig model after implantation into the alveolar bone. These results prompted us to enroll 15 patients with avulsed teeth after traumatic dental injuries in a pilot clinical trial. At 12 months after implantation, bioengineered teeth led to the regeneration of functional teeth, which supported continued root development, in humans. Mechanistically, exosomes derived from hDPSC aggregates mediated the tooth regeneration process by upregulating the odontogenic and angiogenic ability of hDPSCs. Our findings suggest that odontogenic microenvironment engineering by DTM and stem cell aggregates initiates functional tooth regeneration and serves as an effective treatment for tooth avulsion.

Gli1+ Cells Residing in Bone Sutures Respond to Mechanical Force via IP3R to Mediate Osteogenesis.

Early orthodontic correction of skeletal malocclusion takes advantage of mechanical force to stimulate unclosed suture remodeling and to promote bone reconstruction; however, the underlying mechanisms remain largely unclear. Gli1+ cells in maxillofacial sutures have been shown to participate in maxillofacial bone development and damage repair. Nevertheless, it remains to be investigated whether these cells participate in mechanical force-induced bone remodeling during orthodontic treatment of skeletal malocclusion. In this study, rapid maxillary expansion (RME) mouse models and mechanical stretch loading cell models were established using two types of transgenic mice which are able to label Gli1+ cells, and we found that Gli1+ cells participated in mechanical force-induced osteogenesis both in vivo and in vitro. Besides, we found mechanical force-induced osteogenesis through inositol 1,4,5-trisphosphate receptor (IP3R), and we observed for the first time that inhibition of Gli1 suppressed an increase in mechanical force-induced IP3R overexpression, suggesting that Gli1+ cells participate in mechanical force-induced osteogenesis through IP3R. Taken together, this study is the first to demonstrate that Gli1+ cells in maxillofacial sutures are involved in mechanical force-induced bone formation through IP3R during orthodontic treatment of skeletal malocclusion. Furthermore, our results provide novel insights regarding the mechanism of orthodontic treatments of skeletal malocclusion.

SHED aggregate exosomes shuttled miR-26a promote angiogenesis in pulp regeneration via TGF-ß/SMAD2/3 signalling.

OBJECTIVES: Pulp regeneration brings big challenges for clinicians, and vascularization is considered as its determining factor. We previously accomplished pulp regeneration with autologous stem cells from deciduous teeth (SHED) aggregates implantation in teenager patients, however, the underlying mechanism needs to be clarified for regenerating pulp in adults. Serving as an important effector of mesenchymal stem cells (MSCs), exosomes have been reported to promote angiogenesis and tissue regeneration effectively. Here, we aimed to investigate the role of SHED aggregate-derived exosomes (SA-Exo) in the angiogenesis of pulp regeneration. MATERIALS AND METHODS: We extracted exosomes from SHED aggregates and utilized them in the pulp regeneration animal model. The pro-angiogenetic effects of SA-Exo on SHED and human umbilical vein endothelial cells (HUVECs) were evaluated. The related mechanisms were further investigated. RESULTS: We firstly found that SA-Exo significantly improved pulp tissue regeneration and angiogenesis in vivo. Next, we found that SA-Exo promoted SHED endothelial differentiation and enhanced the angiogenic ability of HUVECs, as indicated by the in vitro tube formation assay. Mechanistically, miR-26a, which is enriched in SA-Exo, improved angiogenesis both in SHED and HUVECs via regulating TGF-ß/SMAD2/3 signalling. CONCLUSIONS: In summary, these data reveal that SA-Exo shuttled miR-26a promotes angiogenesis via TGF-ß/SMAD2/3 signalling contributing to SHED aggregate-based pulp tissue regeneration. These novel insights into SA-Exo may facilitate the development of new strategies for pulp regeneration.

Erratum to "Gli1+ Cells Residing in Bone Sutures Respond to Mechanical Force via IP3R to Mediate Osteogenesis".

[This corrects the article DOI: 10.1155/2021/8138374.].

SHED promote angiogenesis in stem cell-mediated dental pulp regeneration.

Dental pulp, plays an indispensable role in maintaining homeostasis of the tooth. Pulp necrosis always causes tooth nutrition deficiency and abnormal root development, which leads to tooth discoloration, fracture or even loss. Our previous study showed implantation of autologous SHED could regenerate functional dental pulp. However, the detailed mechanism of the implanted SHED participating in dental pulp regeneration remains unknown. In this study, we implanted SHED in a porcine dental pulp regeneration model to evaluate the regenerative effect and identify whether SHED promoted angiogenesis in regenerated dental pulp. Firstly we verified that xenogenous SHED had the ability to regenerated pulp tissue of host in vivo. Then we found the vasculature in regenerated pulp originated from implanted SHED. In addition, stem cells were isolated from regenerated dental pulp, which exhibited good multi-differentiation properties and promoted angiogenesis in pulp regeneration process and these results demonstrated that SHED promoted angiogenesis in stem cell-mediated dental pulp regeneration.

Synthesis and anti-CVB3 activity of 4-amino acid derivative substituted pyrimidine nucleoside analogues.

Seven novel 4-amino acid derivative substituted pyrimidine nucleoside analogues were designed, synthesized, and tested for their anti-CVB3 activity. Initial biological studies indicated that among these 4-amino acid derivative substituted pyrimidine nucleoside analogues, 4-N-(2'-amino-glutaric acid-1'-methylester)-1-(2'- deoxy-2'-ß-fluoro-4'-azido)-furanosyl-cytosine 2 exhibited the most potent anti-CVB activity (IC50 = 9.3 µM). The cytotoxicity of these compounds has also been assessed. The toxicity of compound 2 was similar to that of ribavirin.

Effects of valproic acid on the susceptibility of human glioma stem cells for TMZ and ACNU.

To investigate the effect of valproic acid (VPA) on the susceptibility of glioma stem cells to temozolomide (TMZ) and nimustine (ACNU), the O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation and its expression of MGMT were examined. A total of 3 glioma cell populations were isolated from human glioma tissues, and immunocytochemistry was used to detect the expression of MGMT. VPA inhibition on the growth of the 3 glioma cell populations exposed to various concentrations of TMZ and ACNU was evaluated. Flow cytometry was applied to detect the apoptosis of glioma cells, and a methylation-specific polymerase chain reaction was used to identify methylation of MGMT promoter. Immunocytochemistry results indicated that MGMT was negatively expressed in the G1 population, but positively expressed in the G2 and G3 populations. Cell growth inhibition assays demonstrated that the survival rate in the VPA + TMZ or ACNU groups was decreased compared with that of the TMZ or ACNU alone groups (P<0.05). As for the apoptotic rate, those in the VPA alone group were increased compared with the control group (P<0.05), and the rates in the VPA + TMZ or ACNU groups were increased compared with TMZ or ACNU alone groups (P<0.05). The expression of MGMT remained negative in the G1 population following treatment with VPA, but MGMT expression became negative in the 2 MGMT-positive cell populations (G2 and G3) following VPA treatment. The MGMT promoter in the G1 population was partially methylated in the control group, but was fully methylated following VPA treatment, while the promoters of G2, G3 were unmethylated in the control group and became partially methylated in the VPA treatment group. Taken together, TMZ and ACNU may suppress the growth of glioma stem cells in vitro in a dose-dependent manner. VPA may enhance the inhibitory effects of various concentrations of TMZ and ACNU on the growth of MGMT-negative/positive cells, particularly on MGMT-positive cell populations. VPA itself may induce the apoptosis of glioma cells, and VPA combined with TMZ or ACNU may enhance TMZ/ACNU-induced apoptosis of glioma stem cells. Furthermore, VPA may also promote the methylation of the MGMT promoter to silence MGMT expression in glioma cells, which may be an important mechanism through which VPA enhances the efficacy of TMZ and ACNU in targeting glioma stem cells.

Circulating CD14+CD163+CD115+ M2 monocytes are associated with the severity of new onset severe acute pancreatitis in Chinese patients.

BACKGROUND: Despite the role of monocytes in the pathogenesis of severe acute pancreatitis (SAP), it remains unclear how different subtypes of monocytes regulate and contribute to this pathogenesis. METHODS: We examined the numbers of different subsets of monocytes by flow cytometry in 21 SAP, 15 mild acute pancreatitis (MAP) and 13 healthy controls (HC). The concentrations of plasma cytokines were assessed by cytometric bead array. Disease severity was evaluated based on the acute physiology and chronic health evaluation (APACHE) II score and plasma C-reactive proteins (CRP) levels. RESULTS: Compared with the numbers in MAP patients and HC, we observed that the numbers of CD14+CD163-, CD14+CD163-MAC387+, CD14+CD163-IL-12+ M1 monocytes, and CD115+, CD204+, IL-10+ M2 monocytes were significantly increased in SAP patients. In addition, these patients showed higher plasma levels of interleukin (IL)-12 and IL-10. Furthermore, the number of CD14+CD163-, CD14+CD163-MAC387+ M1 monocytes and the plasma IL-12 concentration showed a positive association with the CRP level, while the number of CD204+, IL-10+ M2 monocytes and the plasma IL-10 concentration showed a positive correlation with the APACHE II score. Importantly, the CD115+ M2 subset displayed a positive correlation with both the CRP level and APACHE II score, and treatment of SAP significantly reduced the number of this subset. CONCLUSIONS: The CD14+CD163+CD115+ M2 monocyte count appears to be important factor in determining the severity and prognosis of SAP. Both the pro- and anti-inflammatory monocytes appear to participate in the pathogenesis of SAP.

Downregulation of miR-335-5p by Long Noncoding RNA ZEB1-AS1 in Gastric Cancer Promotes Tumor Proliferation and Invasion.

Recently, long noncoding RNAs (lncRNAs) have emerged as new gene regulators and prognostic biomarkers in several cancers, including gastric cancer (GC). In this study, we investigate the role of lncRNA ZEB1 antisense1 (ZEB1-AS1) on GC progression. In the present study, we found that ZEB1-AS1 expression was upregulated in GC tissues and cell lines. High ZEB1-AS1 expression was significantly correlated with advanced TNM stage, lymph node metastasis, and poor overall survival in GC patients. ZEB1-AS1 suppression reduced GC cell proliferation and invasion in vitro. Tumor formation assay in nude mice showed that ZEB1-AS1 inhibition suppressed GC cell growth. Quantitative real-time PCR showed that miR-335-5p expression was downregulated and negatively correlated with ZEB1-AS1 expression in GC tissues. And miR-335-5p expression was directly regulated by ZEB1-AS1. Furthermore, we found that inhibition of miR-335-5p abrogated the suppression of proliferation and invasion of GC cells induced by ZEB1-AS1 depletion. Collectively, ZEB1-AS1 is critical for the proliferation and invasion of GC cells by regulating miR-335-5p. Our findings indicated that ZEB1-AS1 might offer potential novel therapeutic targets for GC patients.

SLC34A2 regulates miR-25-Gsk3ß signaling pathway to affect tumor progression in gastric cancer stem cell-like cells.

A novel paradigm in tumor biology suggests that gastric cancer progression is driven by gastric cancer stem cell-like cells (GCSCs), but molecular mechanisms regulating tumorigenic and self-renewal potential of GCSCs are still unclear. Here, we aim to investigate biological function of SLC34A2 in regulating sphere formation and tumorigenicity (both are the hallmark of CSCs) of GCSCs and its underlying mechanisms. Our findings testified that CD44+ cells which were derived from fresh primary gastric cancer samples and cell lines displayed stem cell-like features. Significantly, SLC34A2 is increased in CD44+ GCSCs compared with those in adherent counterpart from CD44+ GCSCs. On clinic, SLC34A2 is overexpressed in primary tumor tissues compared with adjacent counterparts. We showed that SLC34A2 regulated sphere formation and self-renewal properties of CD44+ GCSCs in vitro and in vivo. Mechanistic investigations revealed that Gsk3ß was the most strikingly up-regulated gene in response to SLC34A2 knockdown in GCSCs and Wnt/ß-cantenin signaling was required for SLC34A2-mediated sphere formation. Furthermore, SLC34A2 directly binds specific sites in the miR-25 promoter region and that the promoter activity is decreased after the mutation of putative SLC34A2-binding sites, indicating that SLC34A2 is required for the transcriptional induction of miR-25. Meanwhile, luciferase assays showed that miR-25 directly targeted Gsk3ß in CD44+ GCSCs. Overall, our findings define a SLC34A2-miR-25-Gsk3ß pathway in the regulation of GCSCs features and gastric cancer progression, with potential therapeutic applications in blocking their progression.

Synthesis and Anti-HCV Activity of a Novel 2',3'-Dideoxy-2'-α-fluoro-2'-ß-C-methyl Guanosine Phosphoramidate Prodrug.

A novel 2',3'-dideoxy-2'-α-fluoro-2'-ß-C-methyl-6-methoxy guanosine (8) and its phosphoramidate prodrug (1) have been designed and synthesized. Their biological activity was evaluated in both cytotoxicity and cell-based HCV replicon assays. Neither compounds exhibited cytotoxicity up to the highest concentration tested (100 µM) in the Huh-7 cell line. The prodrug (1) displayed nanomolar level antiviral activity (EC50 = 0.39-1.1 µM) against the HCV genotype (GT) 1a, 1b, 2a, and 1b S282T replicons.

Upregulated miR-132 in Lgr5+ gastric cancer stem cell-like cells contributes to cisplatin-resistance via SIRT1/CREB/ABCG2 signaling pathway.

Cisplatin resistance has long been a major problem that restricts its use. A novel paradigm in tumor biology suggests that gastric tumor chemo-resistance is driven by gastric cancer stem cell-like (GCSCs). Growing evidence has indicated that microRNAs (miRNAs) contributes to chemo-resistance in gastric cancer (GC). Here, Lgr5+ cells derived from gastric cancer cell lines displayed stem cell-like features. Flow cytometry demonstrated the presence of a variable fraction of Lgr5 in 19 out of 20 GC specimens. By comparing the miRNA expression profiles of Lgr5+ GCSCs and Lrg5- cells, we established the upregulation of miR-132 in Lgr5+ GCSCs. The enhanced miR-132 expression correlated chemo-resistance in GC patients. Kaplan-Meier survival curve showed that patients with low miR-132 expression survived obviously longer. Functional assays results indicated that miR-132 promoted cisplatin resistance in Lgr5+ GCSCs in vitro and in vivo. Further dual-luciferase reporter gene assays revealed that SIRT1 was the direct target of miR-132. The expression of miR-132 was inversely correlated with SIRT1 in gastric cancer specimens. Furthermore, through PCR array we discovered ABCG2 was one of the downstream targets of SIRT1. Overexpression of SIRT1 down-regulated ABCG2 expression by promoting the de-acetylation of the transcription factor CREB. CREB was further activated ABCG2 via binding to the promoter of ABCG2 to induce transcription. Thus, we concluded that miR-132 regulated SIRT1/CREB/ABCG2 signaling pathway contributing to the cisplatin resistance and might serve as a novel therapeutic target against gastric cancer.