Characterization of novel MSX1 variants causally associated with non-syndromic oligodontia in Chinese families.

BACKGROUND: MSX1 (OMIM #142983) is crucial to normal dental development, and variants in MSX1 are associated with dental anomalies. The objective of this study was to characterize the pathogenicity of novel MSX1 variants in Chinese families with non-syndromic oligodontia (NSO). METHODS: Genomic DNA was extracted from individuals representing 35 families with non-syndromic oligodontia and was analyzed by Sanger sequencing and whole-exome sequencing. Pathogenic variants were screened via analyses involving PolyPhen-2, Sorting-Intolerant from Tolerant, and MutationTaster, and conservative analysis of variants. Patterns of MSX1-related NSO were analyzed. MSX1 structural changes suggested functional consequences in vitro. RESULTS: Three previously unreported MSX1 heterozygous variants were identified: one insertion variant (c.576_577insTAG; p.Gln193*) and two missense variants (c. 871T>C; p.Tyr291His and c. 644A>C; p.Gln215Pro). Immunofluorescence analysis revealed abnormal subcellular localization of the p.Gln193* MSX1 variant. In addition, we found that these MSX1 variants likely lead to the loss of second premolars. CONCLUSION: Three novel MSX1 variants were identified in Chinese Han families with NSO, expanding the MSX1 variant spectrum and presenting a genetic origin for the pathogenesis detected in patients and their families.

Phenotypic characteristics of taurodontism and a novel WNT10A variant in non-syndromic oligodontia family.

OBJECTIVE: Variants in wingless-type MMTV integration site family member 10A (WNT10A) have been proposed to be the most common cause of non-syndromic oligodontia (NSO). The goal of the present study was to identify the novel WNT10A variants in Chinese families with NSO. DESIGN: Clinical data were collected from 39 families with oligodontia admitted to the Hospital of Stomatology Hebei Medical University (China) from 2016 to 2022. Whole-exome sequencing (WES) and Sanger sequencing were performed to identify WNT10A variants in three families with non-syndromic oligodontia. Amino acid conservation analysis and protein conformational analysis were conducted for the WNT10A variant. Genotype-phenotype analysis was performed on the previously reported WNT10A variants related to NSO. RESULTS: We found a novel heterozygous WNT10A variant c.1127 G>A (p.Cys376Tyr) and two reported heterozygous variants c.460 C>A (p.Leu154Met) and c.511 C>T (p.Arg171Cys). Structural modeling showed that the novel WNT10A variant was located in a highly conserved domain, which led to structural damage of WNT10A protein. In addition, we found that the phenotype of the WNT10A variants affected the maxillary second premolars, followed by the mandibular second premolars, and rarely affected the maxillary central incisor. Herein, it is the first time to report that NSO patients with WNT10A monoallele mutation carry taurodontism phenotype and 6.1% prevalence of taurodontism in WNT10A-related NSO patients. CONCLUSIONS: Our results demonstrated that the novel variant c.1127 G>A (p.Cys376Tyr) of WNT10A causes NSO. The present study expanded the known variation spectrum of WNT10A and provided valuable information for genetic counseling of families.

Bibliometric and visualized analysis of the top-100 highly cited articles on immunotherapy for endometrial cancer.

BACKGROUND: Immunotherapy is a promising method for the treatment of endometrial cancer (EC). We aimed to conduct a comprehensive bibliometric study of the top 100 most-cited publications on immunotherapy for EC and provide a reference for future research. METHODS: Global publications on immunotherapy for EC published from 1985 to the present in the Web of Science core database were retrieved. We focused on the study of the top 100 most-cited articles by extracting information such as year, country, journal, author, institution, literature, and keywords. Microsoft Excel, VOSviewer, and R were used to perform descriptive statistics and visual analyses. RESULTS: The top 100 most-cited articles were published between 2002 and 2022, including 70 original papers and 30 reviews. The total frequency of citations per article ranges from 15 to 287. Developed countries dominated these publications, with the United States contributing the most (50 articles). According to Bradford Law, 6 journals, including Gynecologic Oncology and the Journal of Clinical Oncology, are highly recommended. Santin A. D. from Yale University and Makker.V. from Memorial Sloan Kettering Cancer Center have made positive contributions. Among the top ten most-cited articles, 7 focused on clinical trials exploring the efficacy of immunotherapy drugs, of which 4 were lenvatinib combined with pembrolizumab for the treatment of advanced EC. The immune-microenvironment, immune antitumor mechanisms, immunomodulatory drugs, especially anti-pd-1/pd-l1 checkpoint inhibitors, and their clinical trials are the focus of current research. CONCLUSION: The attention of researchers from different countries to EC immunotherapy, especially immunosuppressants, has brought a breakthrough in this field. A large number of clinical trials have evaluated the efficacy and safety of immune agents, and immune combination therapy (especially targeted therapy) shows positive therapeutic promise. Immunodrug sensitivity and adverse events remain urgent issues. The key to promoting the development of EC immunotherapy is to select the best patients according to the molecular classification and immunophenotype such as tumor mutation load, MMR status, pd-l1 expression, tumor infiltrating immune cells to truly achieve accurate and personalized treatment. More new and influential EC immunotherapies, such as adoptive cell immunotherapy, still need to be explored in future clinical practice.

Discovery of 3CLpro inhibitor of SARS-CoV-2 main protease.

Coronavirus main protease (3CLpro), a special cysteine protease in coronavirus family, is highly desirable in the life cycle of coronavirus. Here, molecular docking, ADMET pharmacokinetic profiles and molecular dynamics (MD) simulation were performed to develop specific 3CLpro inhibitor. The results showed that the 137 compounds originated from Chinese herbal have good binding affinity to 3CLpro. Among these, Cleomiscosin C, (+)-Norchelidonine, Protopine, Turkiyenine, Isochelidonine and Mallotucin A possessed prominent drug-likeness properties. Cleomiscosin C and Turkiyenine exhibited excellent pharmacokinetic profiles. Furthermore, the complex of Cleomiscosin C with SARS-CoV-2 main protease presented high stability. The findings in this work indicated that Cleomiscosin C is highly promising as a potential 3CLpro inhibitor, thus facilitating the development of effective drugs for COVID-19.

In this work, computer aided drug design technology was used to study the main protease 3CLpro of novel coronavirus, and functional small molecules with inhibitory effects on novel coronavirus were screened from the compound library of natural products. The results showed that Cleomiscosin C is highly promising as a potential 3CLpro inhibitor with prominent binding affinity, pharmacokinetic profiles and stability.

ARID1A mutations in cancer development: mechanism and therapy.

AT-Rich Interaction Domain 1A (ARID1A) is an important SWItch/Sucrose Non-Fermentation (SWI/SNF) chromatin remodeling complex subunit, and its coding gene has a high mutation frequency in many cancers. Current studies have reported that ARID1A mutational status is correlated to cancer development, including cell proliferation, invasiveness, metastasis, and morphological alterations. ARID1A acts as a tumor suppressor, regulating gene transcription, participating in DNA damage response, and influencing tumor immune microenvironment and signaling pathways. The absence of ARID1A in cancer can lead to widespread dysregulation of gene expression in cancer initiation, promotion, and progression. For patients with ARID1A mutations, effective individualized treatment can improve the prognosis of patients. In this review, we aim to discuss the mechanism of ARID1A mutations in cancer development and explore the significance of discoveries for treatment.

Novel PAX9 compound heterozygous variants in a Chinese family with non-syndromic oligodontia and genotype-phenotype analysis of PAX9 variants

Abstract Studies have reported that >91.9% of non-syndromic tooth agenesis cases are caused by seven pathogenic genes. Objective To report novel heterozygous PAX9 variants in a Chinese family with non-syndromic oligodontia and summarize the reported genotype-phenotype relationship of PAX9 variants. Methodology We recruited 28 patients with non-syndromic oligodontia who were admitted to the Hospital of Stomatology Hebei Medical University (China) from 2018 to 2021. Peripheral blood was collected from the probands and their core family members for whole-exome sequencing (WES) and variants were verified by Sanger sequencing. Bioinformatics tools were used to predict the pathogenicity of the variants. SWISS-MODEL homology modeling was used to analyze the three-dimensional structural changes of variant proteins. We also analyzed the genotype-phenotype relationships of PAX9 variants. Results We identified novel compound heterozygous PAX9 variants (reference sequence NM_001372076.1) in a Chinese family with non-syndromic oligodontia: a new missense variant c.1010C>A (p.T337K) in exon 4 and a new frameshift variant c.330_331insGT (p.D113Afs*9) in exon 2, which was identified as the pathogenic variant in this family. This discovery expands the known variant spectrum of PAX9; then, we summarized the phenotypes of non-syndromic oligodontia with PAX9 variants. Conclusion We found that PAX9 variants commonly lead to loss of the second molars.

Targeting oxidative phosphorylation as an approach for the treatment of ovarian cancer.

Ovarian cancer is an aggressive tumor that remains to be the most lethal gynecological malignancy in women. Metabolic adaptation is an emerging hallmark of tumors. It is important to exploit metabolic vulnerabilities of tumors as promising strategies to develop more effective anti-tumor regimens. Tumor cells reprogram the metabolic pathways to meet the bioenergetic, biosynthetic, and mitigate oxidative stress required for tumor cell proliferation and survival. Oxidative phosphorylation has been found to be altered in ovarian cancer, and oxidative phosphorylation is proposed as a therapeutic target for management of ovarian cancer. Herein, we initially introduced the overview of oxidative phosphorylation in cancer. Furthermore, we discussed the role of oxidative phosphorylation and chemotherapeutic resistance of ovarian cancer. The role of oxidative phosphorylation in other components of tumor microenvironment of ovarian cancer has also been discussed.

Femtosecond Laser Treatment for Improving the Corrosion Resistance of Selective Laser Melted 17-4PH Stainless Steel.

Currently, laser surface treatment (LST) is considered the most promising method available within the industry. It delivers precise control over surface topography, morphology, wettability, and chemistry, making the technique suitable for regulating the corrosion behavior of alloys. In this paper, femtosecond laser texturing with different parameters and atmosphere environments was adopted to clarify the effect of surface treatment on the corrosion resistance of selective laser melted (SLM-ed) 17-4PH stainless steel (SS) in a NaCl solution. The experimental results show that, after the heat treatment, the corrosion resistance of the laser-treated samples was enhanced. With the further laser treatment in an argon atmosphere, the oxidation of nanostructural surfaces was avoided. The Cr, Cu, and other alloying elements precipitated on the laser-ablated surface were beneficial to the formation of a passivation film, leading to an improved corrosion resistance performance.

Pathological pattern of endometrial abnormalities in postmenopausal women with bleeding or thickened endometrium.

BACKGROUND: Postmenopausal bleeding and an endometrial thickness ≥ 5 mm on sonograms of menopausal women can indicate the presence of endometrial lesions. Diagnostic hysteroscopy is a powerful method for endometrial diseases. AIM: To investigate the pathological pattern of endometrial abnormalities in postmenopausal women with bleeding or asymptomatic thickened endometrium diagnosed by hysteroscopy. METHODS: A total of 187 postmenopausal women with bleeding or asymptomatic thickened endometrium underwent diagnostic hysteroscopy. The women were subsequently divided into three groups: Postmenopausal bleeding (PMB) group (n = 84), asymptomatic group (n = 94), and additional group (n = 9). Women in the additional group manifested abdominal pain and leukorrhagia. RESULTS: Among the 187 patients examined, 84 (44.9%) were diagnosed with PMB and 94 (50.3%) with asymptomatic thickened endometrium. Endometrial polyp was the most common endometrial abnormality, which was detected in 51.2%, 76.6% and 77.8% of the PMB, asymptomatic, and additional groups, respectively. In the PMB group, 7 (8.3%) women had hyperplasia with atypia and 14 (16.7%) had endometrial adenocarcinoma. Fewer malignant lesions were detected in the asymptomatic group. Endometrial hyperplasia without atypia was found in 8.3% of the PMB group and 7.4% of the asymptomatic group. CONCLUSION: Endometrial polyp was the most common pathology in the PMB group. Diagnostic hysteroscopy is recommended for women with PMB and asymptomatic thickened endometrium.

Whole-exome sequencing of a novel initiation codon mutation in RUNX2 in a Chinese family with cleidocranial dysplasia.

ABSTRACT: Cleidocranial dysplasia (CCD) is mainly attributable to a variant of runt-related transcription factor 2 (RUNX2) on chromosome 6p21. CCD is an autosomal dominant skeletal disorder characterized by open/delayed closure of fontanels, clavicular hypoplasia, retention of deciduous teeth, and supernumerary permanent teeth. The aim of this study was to investigate potentially pathogenic mutations in 2 Chinese families. Genomic DNA was obtained from peripheral blood lymphocytes, and whole exome sequencing and Sanger sequencing were performed to detect gene variants. Real-time quantitative PCR was performed to determine the mRNA expression level of RUNX2 in the proband of family 1. Silico algorithms and conservation analyses were used to evaluate the functional impact. We identified a novel initiation codon mutation (c.2T>C) and a previously reported mutation (c.569G>A). Familial co-segregation verified an autosomal-dominant inheritance pattern. Our findings demonstrated that the novel mutation c.2T>C causes CCD. Quantitative real-time PCR suggested that downregulated RUNX2 levels and haploinsufficiency in RUNX2 lead to CCD. These results extend the spectrum of RUNX2 mutations in CCD patients and can be used for genetic consultation and prenatal diagnosis.

Correction: PSC-derived Galectin-1 inducing epithelial-mesenchymal transition of pancreatic ductal adenocarcinoma cells by activating the NF-κB pathway.

[This corrects the article DOI: 10.18632/oncotarget.21212.].

A novel human endometrial epithelial cell line for modeling gynecological diseases and for drug screening.

Endometrium-related malignancies including uterine endometrioid carcinoma, ovarian clear cell carcinoma and ovarian endometrioid carcinoma are major types of gynecologic cancer, claiming more than 13,000 women's lives annually in the United States. In vitro cell models that recapitulate "normal" endometrial epithelial cells and their malignant counterparts are critically needed to facilitate the studies of pathogenesis in endometrium-related carcinomas. To achieve this objective, we have established a human endometrial epithelial cell line, hEM3, through immortalization and clonal selection from a primary human endometrium culture. hEM3 exhibits stable growth in vitro without senescence. hEM3 expresses protein markers characteristic of the endometrial epithelium, and they include PAX8, EpCAM, cytokeratin 7/8, and ER. hEM3 does not harbor pathogenic germline mutations in genes involving DNA mismatch repair (MMR) or homologous repair (HR) pathways. Despite its unlimited capacity of in vitro proliferation, hEM3 cells are not transformed, as they are not tumorigenic in immunocompromised mice. The cell line is amenable for gene editing, and we have established several gene-specific knockout clones targeting ARID1A, a tumor suppressor gene involved in the SWI/SNF chromatin remodeling. Drug screening demonstrates that both HDAC inhibitor and PARP inhibitor are effective in targeting cells with ARID1A deletion. Together, our data support the potential of hEM3 as a cell line model for studying the pathobiology of endometrium-related diseases and for developing effective precision therapies.

A novel EDAR missense mutation identified by whole-exome sequencing with non-syndromic tooth agenesis in a Chinese family.

BACKGROUND: Causative variants in genes of the EDA/EDAR/NF-κB pathway, such as EDA and EDARADD, have been widely identified in patients with non-syndromic tooth agenesis (NSTA). However, few cases of NSTA are due to ectodysplasin-A receptor (EDAR) variants. In this study, we investigated NSTA-associated variants in Chinese families. METHODS: Peripheral blood samples were collected from the family members of 24 individuals with NSTA for DNA extraction. The coding region of the EDA gene of the 24 probands was amplified by PCR and sequenced to investigate new variants. Whole-exome sequencing and Sanger sequencing were then performed for probands without EDA variants detected by PCR. RESULTS: A novel missense variant EDAR c.338G>A (p.(Cys113Tyr)) was identified in one family. In addition, three known EDA variants (c.865C>T, c.866G>A, and c.1013C>T) were identified in three families. Genotype-phenotype correlation analysis of EDAR gene mutation showed that NSTA patients were most likely to lose the maxillary lateral incisors and the maxillary central incisors were the least affected. The phenotype of mutations at codon 289 of EDA in NSTA affected patients was characterized by lateral incisors loss, rarely affecting the maxillary first molars. CONCLUSION: A novel EDAR missense variant c.338G>A (p.(Cys113Tyr)) was identified in a family with NSTA, extending the mutation spectrum of the EDAR gene. Genotype-phenotype correlation analyses of EDAR and EDA mutations could help to improve disease status prediction in NSTA families.

Inactivation of Arid1a in the endometrium is associated with endometrioid tumorigenesis through transcriptional reprogramming.

Somatic inactivating mutations of ARID1A, a SWI/SNF chromatin remodeling gene, are prevalent in human endometrium-related malignancies. To elucidate the mechanisms underlying how ARID1A deleterious mutation contributes to tumorigenesis, we establish genetically engineered murine models with Arid1a and/or Pten conditional deletion in the endometrium. Transcriptomic analyses on endometrial cancers and precursors derived from these mouse models show a close resemblance to human uterine endometrioid carcinomas. We identify transcriptional networks that are controlled by Arid1a and have an impact on endometrial tumor development. To verify findings from the murine models, we analyze ARID1AWT and ARID1AKO human endometrial epithelial cells. Using a system biology approach and functional studies, we demonstrate that ARID1A-deficiency lead to loss of TGF-ß tumor suppressive function and that inactivation of ARID1A/TGF-ß axis promotes migration and invasion of PTEN-deleted endometrial tumor cells. These findings provide molecular insights into how ARID1A inactivation accelerates endometrial tumor progression and dissemination, the major causes of cancer mortality.

Extracellular vesicle encapsulated microRNA-320a inhibits endometrial cancer by suppression of the HIF1α/VEGFA axis.

Accumulating evidence indicates that cancer-associated fibroblasts (CAFs) play a crucial role in endometrial cancer (EC) pathogenesis. The present study investigated the clinical significance and biological function of extracellular vesicle (EV) encapsulated miR-320a released from CAFs in EC. EC-related microarray data was obtained from the GSE25405 database and differential analysis was performed. Expression of miR-320a in CAFs and normal endometrial fibroblasts (NFs) as well as CAF-delivered EVs was detected; also, delivery of miR-320a from CAFs to EC cells was observed. In addition we confirmed that miR-320a targets HIF1α via a dual-luciferase reporter assay. Phenotypic analysis was used to study the functional significance of EV delivered miR-320a and its downstream effects. miR-320a was found to have low expression in EC cells and tissues. CAF-secreted EVs were successfully isolated and miR-320a was found also be expressed at low levels in these EVs. Finally, we found direct transfer of CAF-secreted exosomal miR-320a to EC cells, which inhibited their proliferation. Mechanistically, we found this is due to downregulation of HIF1α by miR-320a, which led to lowered VEGFA expression in vitro. Accordingly, we overexpressed HIF1α also showed that the inhibitory effect of miR-320a overexpression in EC cells could be reversed. These results point to CAF-derived EVs carrying overexpressed miR-320a as a novel direction for therapeutic strategies for EC.

A novel EDA1 missense mutation in X-linked hypohidrotic ectodermal dysplasia.

A mutation in the epithelial morphogen gene ectodysplasin-A1 (EDA1) is responsible for the disorder X-linked hypohidrotic ectodermal dysplasia (XLHED), the most common form of ectodermal dysplasia. XLHED is characterized by impaired development of hair, eccrine sweat glands, and teeth. This study aimed to identify potentially pathogenic mutations in four Chinese XLHED families.Genomic DNA was extracted from the peripheral blood and sequenced. Sanger sequencing was used to carry out mutational analysis of the EDA1 gene, and the three-dimensional structure of the novel mutant residues in the EDA trimer was determined. Transcriptional activity of NF-κB was tested by Dual luciferin assay.We identified a novel EDA1 mutation (c.1046C>T) and detected 3 other previously-reported mutations (c.146T>A; c.457C>T; c.467G>A). Our findings demonstrated that novel mutation c.1046C>T (p.A349 V) resulted in XLHED. The novel mutation could cause volume repulsion in the protein due to enlargement of the amino acid side chain. Dual luciferase assay revealed that transcriptional NF-κB activation induced by XLHED EDA1 protein was significantly reduced compared with wild-type EDA1.These results extend the spectrum of EDA1 mutations in XLHED patients and suggest a functional role of the novel mutation in XLHED.

Galectin-1 expression in activated pancreatic satellite cells promotes fibrosis in chronic pancreatitis/pancreatic cancer via the TGF-ß1/Smad pathway.

Chronic pancreatitis/pancreatic cancer (CP/PC) is characterized by fibrous connective tissue proliferation induced by activated pancreatic stellate cells (PSCs). Galectin-1 is upregulated in activated PSCs and is important for the continuing activation of PSCs. The aim of this study was to evaluate the effect of galectin-1 derived from activated PSCs on the progression of fibrosis in CP/PC. To this end, the expression of desmin, α-SMA, galectin-1, fibronectin and collagen type I in normal pancreatic, CP and PC tissues, as well as quiescent/activated PSCs, was investigated. The proliferation rate and migration ability of control, galectin-1-overexpressing and galectin-1-silenced PSCs were also evaluated, as well as the mRNA and protein expression of fibronectin, collagen type I, α-SMA, tissue inhibitors of metalloproteinases (TIMP)-1, MMP-2, Smad2 and TGF-ß1. Furthermore, the effect of adding a TGF-ß1 receptor inhibitor on the expression of these proteins was examined. The results revealed that the expression profile of desmin, α-SMA, galectin-1, fibronectin and collagen type I in the normal pancreas was similar to that of quiescent PSCs and the expression profile in CP/PC tissues was similar to that of activated PSCs. Furthermore, galectin-1-overexpressing PSCs exhibited a significantly higher proliferation rate and migration ability, while galectin-1-silenced PSCs exhibited a significantly lower proliferation rate and migration ability than the control PSCs. The expression of fibronectin, collagen type I, α-SMA, MMP-2 and TIMP-1 was also significantly higher in the galectin-1-overexpressing PSCs than the control PSCs and this effect was found to be mediated by the TGF-ß1/Smad pathway. The trends in the expression of these factors were reversed in the galectin-1-silenced PSCs. From these findings, it can be concluded that overexpression of galectin-1 promotes PSC activity (proliferation and migration) and stimulates fibrosis by increasing extracellular matrix synthesis and decreasing the MMP/TIMP ratio via the TGF-ß1/Smad pathway. Thus, galectin-1 may be a novel candidate for reversing or halting fibrosis progression in CP/PC.

PSC-derived Galectin-1 inducing epithelial-mesenchymal transition of pancreatic ductal adenocarcinoma cells by activating the NF-κB pathway.

Galectin-1 has previously been shown to be strongly expressed in activated pancreatic stellate cells (PSCs) and promote the development and metastasis of pancreatic ductal adenocarcinoma (PDAC). However, the molecular mechanisms by which Galectin-1 promotes the malignant behavior of pancreatic cancer cells remain unclear. In this study, we examined the effects of Galectin-1 knockdown or overexpression in PSCs co-cultured with pancreatic cancer (PANC-1) cells. Immunohistochemical analysis showed expression of epithelial-mesenchymal transition (EMT) markers and MMP9 were positively associated with the expression of Galectin-1 in 66 human PDAC tissues. In addition, our in vitro studies showed PSC-derived Galectin-1 promoted the proliferation, invasion, and survival (anti-apoptotic effects) of PANC-1 cells. We also showed PSC-derived Galectin-1 induced EMT of PANC-1 cells and activated the NF-кB pathway in vitro. Our mixed (PSCs and PANC-1 cells) mouse orthotopic xenograft model indicated that overexpression of Galectin-1 in PSCs significantly promoted the proliferation, growth, invasion, and liver metastasis of the transplanted tumor. Moreover, Galectin-1 overexpression in PSCs was strongly associated with increased expression of EMT markers in both the orthotopic xenograft tumor in the pancreas and in metastatic lesions of naked mice. We conclude that PSC-derived Galectin-1 promotes the malignant behavior of PDAC by inducing EMT via activation of the NF-κB pathway. Our results suggest that targeting Galectin-1 in PSCs could represent a promising therapeutic strategy for PDAC progression and metastasis.

Neurofibromin Regulates Seizure Attacks in the Rat Pilocarpine-Induced Model of Epilepsy.

Studies have shown that neurofibromin (NF1) restricts GABA release at inhibitory synapses and regulates dendritic spine formation, which may play an important role in temporal lobe epilepsy (TLE). NF1 expression was detected by double-label immunofluorescence, immunohistochemistry, and western blot analysis in the brains of pilocarpine-induced epilepsy model rats at 6 h, 24 h, 72 h, 7 days, 14 days, 30 days, and 60 days after kindling. NF1 was localized primarily in the nucleus and cytoplasm of neurons. NF1 protein levels significantly increased in the chronic phase (from 7 days until 60 days) in this epileptic rat model. After NF1 expression was knocked down by specific siRNA, the effects of kindling with pilocarpine were evaluated on the 7th day after kindling. The onset latencies of pilocarpine-induced seizures were elevated, and the seizure frequency and duration were reduced in these rats. Our study demonstrates that NF1 promoted seizure attacks in rats with pilocarpine-induced epilepsy.

[Effect of methylation of hMLH1 gene promotor on stage tumorigenesis and progression of human gastric cancer].

OBJECTIVE: To illustrate the role of methylation level of hMLH1 gene promoter in different stages of gastric carcinogenesis by methylation-specific PCR (MSP) detection of samples from paracancerous tissue and gastric cancer tissue. METHODS: Methylation status of hMLH1 gene promoter of 40 patients undergoing radical stomach cancer operation in the Tumor Research Institute of China Medical University between January 2006 and August 2006 was detected by MSP. For each patient, 2 samples were chosen from the cancer site, paracancerous tissues of 1 cm, 3 cm, 5 cm away from the cancer site, separately. One sample was used in pathology examination, and the other in methylation detection. RESULTS: Positive rates of hMLH1 gene promoter methylation in the paracancerous tissues of 1 cm, 3 cm, 5 cm away from the cancer site were 10%(4/40), 12.5%(5/40) and 2.5%(1/40) respectively, which were significantly lower than 32.5%(13/40) in cancer site(all P<0.05). Pathological examination showed precancerous lesions in 23 samples of paracancerous 1 cm and 3 cm tissues and normal tissues in 24 samples of paracancerous 5 cm tissues. Positive rates of hMLH1 gene promoter methylation in the cancer site, paracancerous tissue and normal gastric tissue were 32.5%(13/40), 8.7%(2/23) and 0(0/24) (P<0.01). For cancer tissue penetrated the gastric serosa, 8 out of 14 tissue samples were positive methylation (57.1%), which was significantly higher compared with 5 out of 26 tissue samples without penetration of gastric serosa(19.2%). Positive rate of hMLH1 gene promoter methylation in tissue samples with 7 or more of metastatic lymphatic node number was 61.5%(8/13), which was higher compared to that with less than 7(5/27, 18.5%) (P<0.05). No significant differences of positive rate of hMLH1 gene promoter methylation were found between different tumor gross types, tumor grow pattern, tumor differentiation degree, patient age and sex(all P>0.05). CONCLUSION: Hypermethylation of hMLH1 gene promoter may be associated with the carcinogenesis stages and progression of human gastric cancer.