Effect of AT-rich interactive domain 1A gene overexpression on glioblastoma cell invasion / 中国医师杂志

Objective:To investigate the role and mechanism of AT-rich interactive domain 1A gene (ARID1A) in glioblastoma invasion.Methods:Human glioblastoma cell line U87 was cultured in vitro. U87 cells transfected with recombinant pcDNA3.1 (+ )-ARID1A by lipofectamine liposome method as ARID1A overexpression group, and U87 cells transfected with empty plasmid as vector group. Untreated U87 cells were as blank control group. The transfection efficiency was verified by real-time fluorescence quantitative polymerase chain reaction (qRT-PCR) and Western blot. Transwell invasion test was used to detect the invasion ability of cells, and Western blot was used to detect the protein expression of c-myc, matrix metalloproteinases (MMP)-2 and MMP-9. Results:48 hours after transfection with ARID1A eukaryotic expression plasmid, the cell invasion ability of ARID1A overexpression group, vector group and blank control group were (42.2±11.5)%, (98.6±4.8)%, (100.0±5.1)%. There was significant difference between ARID1A overexpression group and the other two groups ( P<0.01); The expressions of c-myc, MMP-2 and MMP-9 in ARID1A overexpression group were lower than those in vector group and blank control group ( P<0.01). Conclusions:ARID1A can inhibit the invasion of glioblastoma by inhibiting the expression of MMP-2/MMP-9, and can be used as a potential therapeutic target for glioblastoma.

Comprehensive Cancer Panel Sequencing Defines Genetic Diversity and Changes in the Mutational Characteristics of Pancreatic Cancer Patients Receiving Neoadjuvant Treatment

BACKGROUND/AIMS: Pancreatic ductal adenocarcinoma (PDA) is associated with an extremely poor prognosis. This study assessed the genetic diversity among patients with PDA and compared their mutational profiles before and after treatment. METHODS: Tumors and matched blood samples were obtained from 22 PDA patients treated with neoadjuvant chemoradiation therapy. The somatic mutations were analyzed with comprehensive cancer gene panel (CCP). In addition, the biopsy samples obtained at diagnosis and the surgically resected samples after treatment were compared for seven patients. The CCP provided formalin-fixed paraffin-embedded sample-compatible multiplexed target selection for 409 genes implicated in cancer. RESULTS: Assessments of the MLH1, MLH3, MSH2, and PMS2 genes showed that the four patients with the highest relative burdens of mutations harbored somatic mutations in at least three of these genes. Genes in the histone-lysine N-methyltransferase 2 (KMT2) family, such as KMT2D, KMT2A, and KMT2C, were frequently mutated in tumor samples. Survival was worse in patients with ARID1A gene mutations than those without ARID1A gene mutations. Mutation patterns were compared between tissue samples before and after neoadjuvant treatment in seven patients who underwent surgical resection. The allelic fraction of mutations in KRAS codon 12 was lower in the surgically resected samples than in the endoscopic ultrasonography-guided fine needle aspiration biopsy samples of six patients. The number of mutant alleles of the histone lysine methyltransferase gene WHSC1 also decreased after treatment. CONCLUSIONS: These results indicate that tumor tissue from PDA patients is genetically diverse and suggest that ARID1A mutations may be a potential prognostic marker for PDA.

FSH receptor binding inhibitor up-regulates ARID1A and PTEN genes associated with ovarian cancers in mice

Experiments were conducted to determine if the follicle-stimulating hormone (FSH) receptor binding inhibitor (FRBI) impacts the expression levels of AT-rich interactive domain-containing protein 1A (ARID1A) and phosphatase and tensin homolog (PTEN) in ovaries and blood, as well as expressions of follicle-stimulating hormone cognate receptor (FSHR) gene and proteins. Mice in FRBI-10, FRBI-20, FRBI-30, and FRBI-40 groups were intramuscularly injected with 10, 20, 30, and 40 mg FRBI/kg, respectively, for five consecutive days. Western blotting and qRT-PCR were utilized to determine expression levels of ARID1A and PTEN proteins and mRNAs. Serum ARID1A and PTEN concentrations of the FRBI-40 group were higher than the control group (CG) and FSH group (P<0.05). FSHR mRNA levels of FRBI-20, FRBI-30, and FRBI-40 groups were lower than that of CG and FSH groups on day 15 (P<0.05 or P<0.01). Expression levels of FSHR proteins of FRBI-30 and FRBI-40 groups were lower than those of CG and FSH groups (P<0.05). Levels of ARID1A and PTEN proteins of the FRBI-30 group were greater than CG on days 20 and 30 (P<0.05). FRBI doses had significant positive correlations to levels of ARID1A and PTEN proteins. Additionally, ARID1A and PTEN had negative correlations to FSHR mRNAs and proteins. A high dose of FRBI could promote the expression levels of ARID1A and PTEN proteins in ovarian tissues. FRBI increased serum concentrations of ARID1A and PTEN. However, FRBI depressed expression levels of FSHR mRNAs and proteins in mouse ovaries.

Construction of ARID1A gene mutants and identification of the overexpression in hepatocellular carcinoma cells / 中华实验和临床病毒学杂志

Objective@#To construct the mutants of ARID1A gene, which is an important component in human chromosomal remodeling complex Switch/Sucrose Non Fermentable (SWI/SNF), and identify their overexpression in liver cancer HepG2 cells.@*Methods@#Overlap PCR was used to construct domain truncated mutantss pcDNA6-ARID1A/ΔARID and pcDNA6-ARID1A/ΔD UF3518 based on wild type plasmids pcDNA6-ARID1A. Lipofectionmethod was used to transfect the wild type and mutants into HepG2. Real-time PCR and western blotting were used to confirm the overexpression of ARID1A and the mutants.@*Results@#SDS-PAGE and sequencingresult confirmed the successful construction of pcDNA6-ARID1A/ΔARID and pcDNA6-ARID1A/ΔDUF3518. Real-time PCR and western blottingresult confirmed the overexpression of both mRNA and protein of wild type ARID1A and ARID1A/ΔARID. The mRNA levels indicated that ARID1A/Δ DUF3518 were overexpressed, but the protein levels were quite low.@*Conclusions@#Functional domain truncated mutants of ARID1A were successfully constructed. Overexpression of wild type ARID1A and ARID1A/ΔARID in liver cancer HepG2 cells was successful. Loss of ARID1A/ΔDUF3518 protein suggest that DUF3518 may contribute to the protein structure stability.

Mutational Analysis of Extranodal NK/T-Cell Lymphoma Using Targeted Sequencing with a Comprehensive Cancer Panel

Extranodal natural killer (NK)/T-cell lymphoma, nasal type (NKTCL), is a malignant disorder of cytotoxic lymphocytes of NK or T cells. It is an aggressive neoplasm with a very poor prognosis. Although extranodal NKTCL reportedly has a strong association with Epstein-Barr virus, the molecular pathogenesis of NKTCL has been unexplored. The recent technological advancements in next-generation sequencing (NGS) have made DNA sequencing cost- and time-effective, with more reliable results. Using the Ion Proton Comprehensive Cancer Panel, we sequenced 409 cancer-related genes to identify somatic mutations in five NKTCL tissue samples. The sequencing analysis detected 25 mutations in 21 genes. Among them, KMT2D, a histone modification-related gene, was the most frequently mutated gene (four of the five cases). This result was consistent with recent NGS studies that have suggested KMT2D as a novel driver gene in NKTCL. Mutations were also found in ARID1A, a chromatin remodeling gene, and TP53, which also recurred in recent NGS studies. We also found mutations in 18 novel candidate genes, with molecular functions that were potentially implicated in cancer development. We suggest that these genes may result in multiple oncogenic events and may be used as potential bio-markers of NKTCL in the future.

Clear cell carcinoma of the ovary: molecular insights and future therapeutic perspectives / 부인종양

Clear cell carcinoma (CCC) of the ovary is known to show poorer sensitivity to chemotherapeutic agents and to be associated with a worse prognosis than the more common serous adenocarcinoma or endometrioid adenocarcinoma. To improve the survival of patients with ovarian CCC, the deeper understanding of the mechanism of CCC carcinogenesis as well as the efforts to develop novel treatment strategies in the setting of both front-line treatment and salvage treatment for recurrent disease are needed. In this presentation, we first summarize the mechanism responsible for carcinogenesis. Then, we highlight the promising therapeutic targets in ovarian CCC and provide information on the novel agents which inhibit these molecular targets. Moreover, we discuss on the cytotoxic anti-cancer agents that can be best combined with targeted agents in the treatment of ovarian CCC.

Advances in research on ARID1 A in Malignancies / 基础医学与临床

SWI/SNF is an ATP-dependent chromatin remodeling complex .ARID1 A gene is an important subunit of SWI/SNF complex and its dysfunction can cause abnormal chromatin remodeling , resulting in tumorigenesis .AR-ID1A occurs frequently low expression or deletion mutation in a variety of malignant tumors , such as ovarian canc-er, liver cancer, breast cancer, stomach cancer, lung cancer and so on, which indicates that ARID1A is an impor-tant tumor suppressor gene .

Loss of ARID1A Expression in Gastric Cancer: Correlation with Mismatch Repair Deficiency and Clinicopathologic Features

PURPOSE: The AT-rich interactive domain 1A (ARID1A) gene encodes BRG1-associated factor 250a, a component of the SWItch/Sucrose NonFermentable chromatin remodeling complex, which is considered a tumor suppressor in many tumors. We aimed to investigate the prognostic significance of ARID1A expression in gastric cancers and explore its relationship with clinicopathologic parameters such as mismatch repair protein expression. MATERIALS AND METHODS: Four tissue microarrays were constructed from 191 resected specimens obtained at Soonchunhyang University Cheonan Hospital from 2006 to 2008. Nuclear expression of ARID1A was semiquantitatively assessed and binarized into retained and lost expression. RESULTS: Loss of ARID1A expression was observed in 62 cases (32.5%). This was associated with more frequent vascular invasion (P=0.019) and location in the upper third of the stomach (P=0.001), and trended toward more poorly differentiated subtypes (P=0.054). ARID1A loss was significantly associated with the mismatch repair-deficient phenotype (P=0.003). ARID1A loss showed a statistically significant correlation with loss of MLH1 (P=0.001) but not MSH2 expression (P=1.000). Kaplan-Meier survival analysis showed no statistically significant difference in overall survival; however, patients with retained ARID1A expression tended to have better overall survival than those with loss of ARID1A expression (P=0.053). In both mismatch repair-deficient and mismatch repair-proficient groups, survival analysis showed no differences related to ARID1A expression status. CONCLUSIONS: Our results demonstrated that loss of ARID1A expression is closely associated with the mismatch repair-deficient phenotype, especially in sporadic microsatellite instability-high gastric cancers.

Loss of Tumor Suppressor ARID1A Protein Expression Correlates with Poor Prognosis in Patients with Primary Breast Cancer / 한국유방암학회지

PURPOSE: Somatic mutations of the chromatin remodeling AT-rich interactive domain 1A (SWI-like) gene (ARID1A) have been identified in many human cancers, including breast cancer. The purpose of this study was to evaluate the nuclear expression of ARID1A in breast cancers by immunohistochemistry (IHC) and to correlate the findings to clinicopathologic variables including prognostic significance. METHODS: IHC was performed on tissue microarrays of 476 cases of breast cancer. Associations between ARID1A expression and clinicopathologic characteristics and molecular subtype were retrospectively analyzed. RESULTS: Low expression of ARID1A was found in 339 of 476 (71.2%) cases. Low expression of ARID1A significantly correlated with positive lymph node metastasis (p=0.027), advanced pathologic stage (p=0.001), low Ki-67 labeling index (p=0.003), and negative p53 expression (p=0.017). The ARID1A low expression group had significantly shorter disease-free and overall survival than the ARID1A high expression group (p<0.001 and p<0.001, respectively). Multivariate analysis demonstrated that low expression of ARID1A was a significant independent predictive factor for poor disease-free and overall survival in patients with breast cancer (disease-free survival: hazard ratio, 0.38, 95% confidence interval [CI], 0.20-0.73, p=0.004; overall survival: hazard ratio, 0.11, 95% CI, 0.03-0.46, p=0.003). In patients with luminal A type disease, patients with low ARID1A expression had significantly shorter disease-free and overall survival rates than patients with high ARID1A expression (p=0.022 and p=0.018, respectively). CONCLUSION: Low expression of ARID1A is an independent prognostic factor for disease-free and overall survival in breast cancer patients and may be associated with luminal A type disease. Although the biologic function of ARID1A in breast cancer remains unknown, low expression of ARID1A can provide valuable prognostic information.

Decreased ARID1A expression is correlated with chemoresistance in epithelial ovarian cancer / 부인종양

OBJECTIVE: Loss of ARID1A is related to oncogenic transformation of ovarian clear cell adenocarcinoma. The present study was conducted in epithelial ovarian cancer of all tissue types to investigate whether an increased or decreased expression level of ARID1A can be a prognostic factor for ovarian cancer or can influence the sensitivity to anticancer drugs. METHODS: The expression level of ARID1A was investigated in 111 patients with epithelial ovarian cancer who received initial treatment at the Hirosaki University Hospital between 2006 and 2011. The expression level of ARID1A was immunohistochemically graded using staining scores, which were calculated by multiplying the staining intensity of the nuclei by the stain-positive area. RESULTS: The level of ARID1A was significantly lower in clear cell adenocarcinoma than in other histologic types. Among the patients with stage III, IV cancer (n=46), the level of ARID1A was significantly lower (p=0.026) in patients who did not achieve complete response (CR; n=12) than in patients who achieved CR (n=34). The level of ARID1A was relatively lower (p=0.07) in patients who relapsed after achieving CR (n=21) than in patients who did not relapse (n=13). When the staining score of 0 was defined as ARID1A-negative and other staining scores were defined as ARID1A-positive, there was significant difference in progression-free survival between ARID1A-negative (n=11) and ARID1A-positive (n=35) patients in stage III, IV disease. CONCLUSION: The result suggests that decreased ARID1A expression is correlated with chemoresistance and may be a predictive factor for the risk of relapse of advanced cancer after achieving CR.

The roles of ARID1A in gynecologic cancer / 부인종양

One of the exciting findings in recent cancer genome studies is the discovery of somatic mutations in several chromatin remodeling genes. These studies not only illuminate the emerging roles of chromatin remodeling in the pathogenesis of human cancer but also provide molecular genetic basis of aberrant epigenomic regulation as one of the key mechanisms driving cancer development. This is because chromatin remodeling influences a variety of DNA activities such as replication, transcription, repair, methylation, and recombination. Among the mutated chromatin remodeling genes reported, ARID1A is frequently mutated in a variety of human cancers, especially in endometrium-related neoplasms including ovarian clear cell carcinoma, ovarian endometrioid carcinomas, and uterine endometrioid carcinomas, all of which arise from endometrial epithelium. This review will summarize the recent advances in studying the roles of ARID1A mutations in gynecologic cancers with special emphasis on how this new knowledge will further extend our understanding of the pathogenesis of endometrium-related carcinomas.