AT-rich Interactive Domain 1A Gene Research Articles

The mutation and low expression of ARID1A are predictive of a poor prognosis and high immune infiltration in triple-negative breast cancer.

Triple-negative breast cancer (TNBC) has the poorest prognosis among all breast cancer subtypes. While several tumor types are excepted to have a curative response to immunotherapy through the AT-rich interaction domain 1A (ARID1A) gene, its role in TNBC remains unclear. The expression of the ARID1A gene and immune infiltration in TNBC were analyzed by way and function enrichment analysis. Additionally, 27 gene mutations, including ARID1A mutation, were detected in paraffin-embedded TNBC specimens and normal breast specimens using Next Generation Sequencing (NGS). Immunohistochemical staining was employed to detect the expression of AIRD1A, TP53, Ki67, CD4, CD8, and PD-L1 proteins in TNBC and the adjacent normal tissue samples. The bioinformatics analysis revealed that ARID1A was mutated in TNBC and significantly associated with tumor immune infiltration. NGS analysis showed a high mutation rate of ARID1A (35%) in TNBC, but the mutation status of ARID1A was not associated with age at onset, lymph node metastasis, pathological grade, or Ki67 index. Low expression or loss of AIRD1A was more commonly observed in TNBC tissues (36/108) as compared to normal tissues (3/25). Positive expression of CD8 and PD-L1 was observed in TNBC tissues with low ARID1A expression. ARID1A mutation was associated with low protein expression, and patients with ARID1A mutation or low protein expression had shorter progression-free survival. The ARID1A mutation and low expression are associated with poor prognosis and high immune infiltration in TNBC, and might be biomarkers for TNBC prognosis and immunotherapy efficacy.

The Role of the AT-Rich Interaction Domain 1A Gene (ARID1A) in Human Carcinogenesis.

The switch/sucrose non-fermentable (SWI/SNF) (SWI/SNF) complex uses energy from ATP hydrolysis to mobilise nucleosomes on chromatin. Components of SWI/SNF are mutated in 20% of all human cancers, of which mutations in AT-rich binding domain protein 1A (ARID1A) are the most common. ARID1A is mutated in nearly half of ovarian clear cell carcinoma and around one-third of endometrial and ovarian carcinomas of the endometrioid type. This review will examine in detail the molecular functions of ARID1A, including its role in cell cycle control, enhancer regulation, and the prevention of telomerase activity. ARID1A has key roles in the maintenance of genomic integrity, including DNA double-stranded break repair, DNA decatenation, integrity of the cohesin complex, and reduction in replication stress, and is also involved in mismatch repair. The role of ARID1A loss in the pathogenesis of some of the most common human cancers is discussed, with a particular emphasis on gynaecological cancers. Finally, several promising synthetic lethal strategies, which exploit the specific vulnerabilities of ARID1A-deficient cancer cells, are briefly mentioned.

Explore the alterations of downstream molecular pathways caused by ARID1A mutation/knockout in human endometrial cancer cells.

As one of the most common gynecologic malignancies, endometrial cancer (EC) is driven by multiple genetic alterations that may be targeted for treatments. AT-rich interaction domain 1A (ARID1A) gene mutations were reported as early events in endometrial carcinogenesis. To explore the alterations of downstream molecular pathways caused by ARID1A mutations and the associated therapeutic implications, we edited ARID1A gene in human endometrial cancer cell line Ishikawa using the Clustered Regularly Interspaced Short Palindromic Repeats and CRISPR-Associated Proteins (CRISPR/Cas9) technology. We successfully constructed a stable Ishikawa cell line with a confirmed 10bp deletion on the ARID1A gene, which resulted in a code-shift mutation and gene knockout. Compared with unedited wild-type cells, ARID1A knockout (KO) led to reduced apoptosis, accelerated transformation from G0/G1 to S phase, and enhanced cell proliferation. ARID1A deficiency would reduce the protein levels of p21, caspase 7, and caspase 9 in Ishikawa endometrial cancer cells compared with the wild-type cells. In addition, ARID1A KO resulted in high levels of microsatellite instability (MSI-H). Moreover, transcriptomic analyses showed that ARID1A KO can lead to activated phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling. Furthermore, experimental analyses demonstrated that ARID1A KO cells had reduced expression of genetic instability-associated markers mutL homologue 1 (MLH1) and progesterone receptor B (PR) and increased p-Akt expression. These findings support further exploration of ARID1A as a therapeutic target for EC and provide insight into developing more effective treatments in EC, such as the combinatory use of immune checkpoint inhibitors.

Met stimulates ARID1A degradation and activation of the PI3K-SREBP1 signaling to promote milk fat synthesis in bovine mammary epithelial cells

Methionine (Met) can promote milk fat synthesis in bovine mammary epithelial cells (BMECs), but the potential molecular mechanism is largely unknown. In this report, we aim to explore the role and molecular mechanism of AT-rich interaction domain 1A (ARID1A) in milk fat synthesis stimulated by Met. ARID1A knockdown and activation indicated that ARID1A negatively regulated the synthesis of triglycerides, cholesterol and free fatty acids and the formation of lipid droplets in BMECs. ARID1A also negatively regulated the phosphorylation of PI3K and AKT proteins, as well as the expression and maturation of SREBP1. Met stimulated the phosphorylation of PI3K and AKT proteins, as well as the expression and maturation of SREBP1, while ARID1A gene activation blocked the stimulatory effects of Met. We further found that ARID1A was located in the nucleus of BMECs, and Met reduced the nuclear localization and expression of ARID1A. ARID1A gene activation blocked the stimulation of PI3K and SREBP1 mRNA expression by Met. In summary, our data suggests that ARID1A negatively regulates milk fat synthesis stimulated by Met in BMECs through inhibiting the PI3K-SREBP1 signaling pathway, which may provide some new perspectives for improving milk fat synthesis.

Clinical and mutational profile of AT-rich interaction domain 1A-mutated cancers.

AT-rich interaction domain 1A (ARID1A) encodes a key component of the SWItch/Sucrose Non-Fermentable (SWI/SNF) chromatin remodeling complex that participates in gene expression. ARID1A alterations are quite common among cancer patients, although their role remains debated. The aim of this article was to study ARID1A-mutated cancer patients. Molecular and clinical data of cancer patients evaluated at Phase 1 Unit of Fondazione Policlinico Universitario A. Gemelli IRCCS were collected. Molecular analyses were performed using FoundationOne® CDx (Foundation Medicine Inc., Cambridge, MA, United States). Cancer patients with at least one molecular alteration in ARID1A gene were identified as ARID1A+. Among the 270 patients undergoing molecular analysis, we found 25 (9%) with at least one pathogenic alteration in ARID1A. The vast majority of these patients were female (84%). The median age at diagnosis was 59; most of the cancers (15, 60%) were gynecological (especially endometrioid endometrial cancers and clear cell ovarian cancers), diagnosed at an early stage. Frameshift alterations in ARID1A were the most common (19/31, 61%) alterations. The median number of mutations in ARID1A+ population was higher compared to ARID1A- population (6 vs. 4), as well as tumor mutational burden (TMB) [20 mutations/megabase (mut/Mb) vs. 1.26 mut/Mb]. Phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA), phosphatase and tensin homolog (PTEN), catenin beta 1 (CTNNB1), and lysine methyltransferase 2D (MLL2) mutations were enriched in ARID1A+ population. In this cohort, ARID1A did not display any relation with response to platinum chemotherapy. Cancers with double alterations in ARID1A (ARID1A2+) were all gynecological cancers (83% endometrioid endometrial cancers). This analysis provides clinical and molecular details about the phenotypes of ARID1A+ cancers, in particular the subgroup of gynecologic cancers. The high frequency of concurrent mutations in the phosphoinositide 3-kinase (PI3K) pathway among endometrioid endometrial cancers may support the proposal of a new treatment strategy based on the combination of ataxia telangiectasia and Rad3-related (ATR) inhibitor and PIK3CA inhibitor.

ARID1A expression in hepatocellular carcinoma and relation to tumor recurrence after microwave ablation.

Aim of the studyAT-rich interactive domain 1A (ARID1A) is a subunit of the switch/sucrose non-fermentable chromatin remodeling complex, which is commonly mutated in human cancers. The clinical and pathological significance of ARID1A alteration in hepatocellular carcinoma (HCC) has not yet been clarified. The present study aimed to evaluate the clinical significance of the ARID1A gene signature in HCC and its relation to the likelihood of tumor recurrence after microwave ablation (MWA).Material and methodsThis study included 50 patients with cirrhotic HCC of Barcelona Clinic Liver Cancer stages 0/A eligible for MWA. Tumor and peri-tumor biopsies were obtained just prior to MWA and assessed for tumor pathological grade and ARID1A expression by immunohistochemistry. Patients were followed for one year after complete tumor ablation to detect any recurrence.ResultsTumor size (MCp = 0.010) and α-fetoprotein level (p = 0.013) can effectively predict the response to MWA. Nuclear expression of ARID1A was significantly lower in HCC compared to the corresponding peri-tumor cirrhotic liver tissues (p = 0.002), but no significant difference in ARID1A cytoplasmic expression was found. Nuclear ARID1A expression level in HCC showed a significantly negative relation to tumor size (MCp = 0.006), pathological grade (MCp = 0.046) and post-MWA tumor recurrence (FEp = 0.041).ConclusionsARID1A loss may enhance HCC aggressiveness and post-MWA tumor recurrence. ARID1A could be a potential target to select HCC patients for future therapies.

Methionine and leucine induce ARID1A degradation to promote mTOR expression and milk synthesis in mammary epithelial cells

Amino acids can activate mTOR to promote milk synthesis in mammary epithelial cells (MECs), but the underlying molecular mechanism is still largely unknown. The objective is to investigate the regulatory mechanism of amino acids (Met and Leu) in stimulating mRNA expression of mTOR in MECs. We found that the protein abundance of AT-rich interaction domain 1A (ARID1A) was poorly expressed in mouse mammary gland tissues of lactating period. ARID1A knockdown and gene activation experiments detected whether ARID1A negatively regulated milk protein and fat synthesis in bovine MECs, cell proliferation and the expression and activation of mTOR. ChIP-PCR detected that ARID1A, H3K27ac, H3K27me3 and H3K4me3 all bound to the mTOR promoter at -548∼-793 nt. Knockdown or gene activation of ARID1A enhanced or weakened the binding of H3K27ac on the mTOR promoter, respectively. The stimulation of Met and Leu on mTOR expression and phosphorylation were eliminated by ARID1A gene activation. Furthermore, Met and Leu decreased the protein level of ARID1A through ubiquitination and proteasomal degradation. TRIM21 bound to ARID1A, and TRIM21 knockdown blocked the stimulation of Met and Leu on ARID1A degradation. In summary, these data reveal that ARID1A blocks Met and Leu signaling to mTOR gene transcription through inhibiting H3K27ac deposition on its promoter, and Met and Leu decrease ARID1A protein level through TRIM21-mediated ubiquitination and proteasomal degradation. Our findings uncover that Met and Leu promote mTOR expression for milk synthesis through the TRIM21-ARID1A signaling pathway, providing a novel theoretical basis for the application of amino acids in milk production.

Landscape of EBV-positive gastric cancer.

Epstein-Barr virus-positive gastric cancer [EBV (+) GC] is associated with EBV infection and is one of the GC subtypes defined by the Cancer Genome Atlas. EBV (+) GC has several distinct genomic or epigenomic features and clinicopathological characteristics compared with other molecular subtypes of GC. Here, we summarize the unique features of EBV (+) GC including the clinical and histopathological features, and discuss associated genetic and epigenetic aberrations. We also discuss noncoding RNAs [EBV-encoded RNAs and EBV-encoded microRNAs (miRNAs)] derived from EBV-infected cells, which have not been described in detail previously. These noncoding RNAs are defined by their roles; for example, EBV-encoded miRNAs play pivotal roles in oncogenesis and tumor progression in EBV (+) GC. We also discuss recent advances in therapeutic modalities for EBV (+) GC, as well as the potential of EBV infection as a predictive biomarker of the response to anti-PD-1 therapy with immune checkpoint inhibitors. We introduce our recent studies focusing on AT-rich interactive domain 1A gene mutations and programmed death ligand-1 overexpression/CD274 copy-number amplification, which are recurrently identified in EBV (+) GC. Finally, based on those findings, we propose potential therapeutic options using candidate-targeted therapies against EBV (+) GC.

AT-rich interactive domain1A determines sensitivity to oxaliplatin in gastric cancer cells.

BackgroundGastric cancer is a highly heterogeneous disease and its traditional histopathological classification is difficult to meet clinical needs. Oxaliplatin is an antitumor drug with high efficiency and low toxicity. Therefore, the insensitivity or secondary drug resistance of oxaliplatin to gastric cancer is vital for tumor progression. The aim of this study was to investigate the sensitivity of gastric cancer cells to oxaliplatin after ARID1A (AT-rich interactive domain1A gene) gene silencing.MethodsMGC-803 and AGS cells were selected as gastric cancer cells for study. ARID1A protein and mRNA expression was detected by Western blot and quantitative reverse-transcription PCR (qRT-PCR). The short hairpin RNA (shRNA) fragment of ARID1A gene silencing was constructed and introduced into gastric cancer cells. The cell proliferation activity was calculated using CCK8 and the IC50 was calculated. The flow cytometry was used to detect the cell cycle and apoptosis rate. The ability of cell invasion was detected by transwell method. Cells were treated with different concentrations of oxaliplatin.ResultsThe proliferation of gastric cancer cells was promoted by ARID1A gene silencing (P<0.01), the quantity of cells in S phase increased (P<0.05), and the invasive ability increased (P<0.05). After treatment with oxaliplatin at different concentrations, ARID1A gene silencing reduced the inhibition rate of oxaliplatin on gastric cancer cells and apoptosis rate (P<0.05), and increased IC 50 (P<0.01).ConclusionsARID1A gene silencing, a factor promoting proliferation of gastric cancer cells, would reduce the sensitivity of gastric cancer cells to oxaliplatin, which can provide a basis for the exploration of targeted drugs for individualized treatment of gastric cancer.

A pan-cancer analysis of ARID1A as a potential biomarker for immune checkpoint therapy.

3540 Background: AT-rich interactive domain 1A (ARID1A), encoding a subunit of the BAF (SWI/SNF) chromatin remodeling complex, is correlated with the origination and progress of tumor. Previous research on ARID1A gene revealed that ARID1A deficiency was associated with mismatch repair (MMR) and higher tumor mutation burden (TMB) level in cancer, which might cooperate with immune checkpoint blockade therapy. Methods: Next generation sequencing (NGS) data of 10336 pan-cancer patients were obtained from the MSK-IMPACT Clinical Sequencing cohort (MSKCC). NGS data of 15849 pan-cancer patients from Chinese clinical dataset were analyzed to explore the association between ARID1A gene mutation and TMB. TMB was defined as total number of somatic non-synonymous mutations in coding region. 853 advanced NSCLC patients from two independent cohorts (OAK study cohort and POPLAR study cohort) were used to analyze the correlation between ARID1A alteration and the efficacy of immune checkpoint blockade immunotherapies (ICIs). Results: In total, 8.62% (891/10336) of pan-cancer patients in MSKCC harbored ARID1A mutation and 8.47% (3188/37628) in Chinese cohort. In MSKCC cohort, the highest ARID1A mutation frequency tumor type was endometrial cancer (31.64%, 69/218), bladder cancer (26.95%, 114/423) and hepatobiliary cancer (17.18%, 61/355) come in second and third, respectively. While in Chinese cohort, the top three ARID1A mutation frequency tumor types were endometrial cancer (39.29%, 88/224), gastric carcinoma (17.80%, 318/1787) and urothelial carcinoma (17.18%, 83/483), respectively. ARID1A gene mutation was also associated with higher TMB in the Chinese pan-cancer cohort (P &lt; 0.0001). The highest medium TMB level of ARID1A mutation tumor type was Urothelial carcinoma with 18.63 Muts/Mb (n = 65). In addition, the TMB level and prognositic analysis were performed on patients in two independent NSCLC cohorts with ICIs, TMB level of ARID1A mutant group was higher than wild-type group with significant difference (P &lt; 0.0001). The overall survival (OS) of ARID1A mutation group were significantly shorter than wild-type group (OS, median, 6.80 vs 10.28 months; HR, 1.47; P = 0.0474), and a decreasing trend on progression-free survival (PFS) without significant difference (median, 1.46 vs 2.99 months; HR, 1.27; P = 0.1584). Conclusions: The results indicated that ARID1A gene mutation was associated with a higher TMB level in Chinese pan-cancer patients, and patients harboring these genes mutations might easily benefit from ICIs.

Hepatocellular carcinoma with ARID1A mutation is associated with higher TMB and poor survival.

e16667 Background: Hepatocellular carcinoma (HCC) is a heterogeneous disease that lacks molecular predictors of response to available treatments. AT-rich interactive domain 1A (ARID1A), a SWI/SNF chromatin remodeling gene, is commonly mutated in human cancers and hypothesized to be a tumor suppressor gene. In recent years, immune checkpoint blockade immunotherapies (ICIs) are promising therapies for multiple cancers including HCC, and tumor mutation burden (TMB) was an important biomarker to predict the efficacy of ICIs. Besides, previous research reported that ARID1A deficiency was associated with mismatch repair (MMR) in cancer, and may cooperated with ICIs. Methods: Whole exome sequencing data of 10336 pan-cancer patients including 353 HCC patients was obtained from the Cancer Genome Altas (TCGA). Next generation sequencing (NGS) data of 15849 pan-cancer patients including 1926 HCC patients from Chinese clinical dataset were analyzed to explore the correlation between ARID1A gene mutation and TMB. TMB was defined as total number of somatic non-synonymous mutations in coding region. Prognostic data of 136 HCC patients were obtained from the MSK-IMPACT Clinical Sequencing Cohort (MSKCC). Results: In total, 8.62% (891/10336) of pan-cancer patients in TCGA harboring ARID1A mutation and 8.47% (3188/37628) in Chinese cohort, while mutant percentage of HCC was 9.35% (33/353) in TCGA, 9.03% (174/1926) in Chinese cohort, the alternation frequency of ARID1A in two cohorts was no significant difference (P = 0.3334). The medium TMB level of ARID1A mutant group was higher than wild-type group with significant difference both in Chinese pan-cancer and HCC (medium TMB level, P &lt; 0.0001). Results of 18 kinds of ARID1A mutated tumors patients in TCGA cohort indicated that ARID1A mutation was an independent risk factor in liver cancer affecting overall survival (OS, HR 2.43, 95% IC 1.07-5.54, P = 0.0286). Besides, Kaplan-Meier analysis was performed on HCC patients in MSKCC cohort, ARID1A statue resulted in significantly shorter OS (median, 12.2 vs 21.43 months; HR 2.5; P = 0.0092). Conclusions: The results indicated that ARID1A gene mutation was a poor prognostic factor in hepatocellular carcinoma, and these mutational states were associated with higher TMB level, which might be a potential positive biomarker of immunotherapy.

AT-rich Interaction Domain 1A Gene Variations: Genetic Associations and Susceptibility to Gastric Cancer Risk

AT-rich interaction domain containing protein 1A (ARID1A), has recently emerged as a novel class of gene which acts as a potent tumor suppressor in numerous types of cancers such as Gastric, Breast, Ovarian, Colorectal, Lung cancers. ARID1A is involved in the regulation of various cellular processes such as proliferation, differentiation and DNA repair, yet its association with the susceptibility of cancer remains unknown. Here, we aimed to analyse the association of the ARID1A variants (Pro912Thr, Gln944Lys and Gln920Ter) with the risk of Gastric cancer (GC) in Kashmiri population. The study included 103 confirmed cases of GC and 163 normal controls. The genotypes were studied using Polymerase Chain Reaction. Different bioinformatic predictive tools were also used to analyse the possible effect of these SNP's on the resultant protein. The Pro912Thr and Gln920Ter variants of ARID1A showed significant difference in genotypic and allelic frequencies between the GC cases and controls (P < 0.05), whereas, the data did not reveal any correlation between Gln944Lys variant and Gastric cancer risk. Both Pro912Thr and Gln920Ter SNP's follow "Dominant mode of inheritance". In Silico analysis predicted that amino acid substitution of Pro912Thr SNP decreases the protein stability thus changing the functional properties of resultant protein, so backing the possibility of damaging effect of this SNP. Our study suggests that Pro912Thr and Gln920Ter SNP's of ARD1A gene are associated with increased risk of GC in Kashmiri population.

ARID1a as a marker of prognosis and increased sensitivity to CDK4/6, mTOR 1/2 and Src homology region 2 phosphatase (SHP 1/2) inhibitors in breast cancer (BC).

1082 Background: ARID1a (AT Rich Interactive Domain 1A) is part of the SWI/SNF complex, which regulates gene transcription, and is believed to be a tumor suppressor gene. Low ARID1a expression has been associated with poor prognosis in BC. The aim of this study was to explore the clinical significance of ARID1a mutation and expression loss, and its potential as a therapeutic target in BC. Methods: We analyzed publicly available genomic databases to study the clinical implication of ARID1a mutations and gene expression in BC. Results: ARID1a was mutated in ~5-7 % of BCs within TCGA/METABRIC/MSK (5511 samples), but did not show differences in frequency between histology, grade, or estrogen receptor (ER)/HER2 receptor status. MSK metastatic tissue samples had higher incidence of ARID1a mutation compared to primary tumor samples (7.6% vs 4.4%, χ2 P = 0.0073). Analysis of ARID1a in KMPLOT showed that lower gene expression was associated with worse relapse-free survival and overall survival across all BCs, but the difference was primarily in molecularly classified luminal A tumors. Mutations in ARID1a did not show an association with outcomes in TCGA/METABRIC/MSK datasets. Pathway analysis of ARID1a showed it is involved in regulating ER ligand driven signaling and interacts with targets regulated by CDK4 and mTOR activity. CancerRxgene drug sensitivity analyses on BC cell lines revealed that ARID1a mutated BC cell lines were significantly more sensitive to palbociclib, SHP1/2, and mTOR1/2 inhibitors compared to ARID1a wildtype cell lines. Conclusions: Reduced activity of ARID1a in luminal BC cells may negatively affect prognosis by altering ER signaling leading to activation of druggable resistance mechanisms, particularly in metastatic tissue. Loss of function ARID1a mutations may sensitize cancer cells to CDK4/6, mTOR1/2, and SHP1/2 inhibitors in vitro. Further research in ARID1a mutated ER+ BCs using combinations of these inhibitors is warranted.

The Role of ARID1A in Endometrial Cancer and the Molecular Pathways Associated With Pathogenesis and Cancer Progression.

AT-rich interaction domain 1A gene (ARID1A) encodes for a subunit of the switch/sucrose non-fermentable (SWI/SNF) complex, a chromatin remodeling complex, and it has been implicated in the pathogenesis of various cancer types. In this review, we discuss how ARID1A is linked to endometrial cancer and what molecular pathways are affected by mutation or inhibition of ARID1A. We also discuss the potential use of ARID1A not only as a prognostic biomarker, but also as a target for therapeutic interventions.

Prevalence of common polymorphisms of AT-rich interaction domain 1A and endothelial nitric oxide synthase in patients with endometriosis compared to control group

Introduction: Endometriosis is a common gynecologic disorder defined as ectopic presence of endometrial tissue in extrauterine sites. Endometriosis is associated with infertility and risk of malignancy. Identification of genetic factors responsible for development and malignant transformation of endometriosis can improve therapeutic approaches. In this study, we investigated the association of AT-rich interaction domain 1A ( ARID1A) and endothelial nitric oxide synthase ( eNOS) polymorphisms with endometriosis and staging of the disease. Methods: A total of 100 women with laparoscopy-confirmed diagnosis of endometriosis were included and compared with 100 women without endometriosis as the control group. Genotypes of patients regarding Gln920Ter polymorphism of ARID1A gene and Glu298Asp polymorphism of eNOS gene were determined by polymerase chain reaction techniques on blood samples from the study population. The prevalence of each genotype in endometriosis patients was compared with healthy controls using the chi-square test. Results: Significantly higher prevalence of non-CC genotype for ARID1A Gln920Ter polymorphism and non-GG genotype for G894T polymorphism of the eNOS gene was detected in the endometriosis group. There was no significant relationship between these polymorphisms and staging of endometriosis. Discussion: Significant variation of prevalence of Gln920Ter polymorphism of the ARID1A gene and Glu298Asp polymorphism of the eNOS gene among the two groups can indicate a causative effect of these genetic alterations on the development of endometriosis.

Loss of ARID1A Expression Correlates With Tumor Differentiation and Tumor Progression Stage in Pancreatic Ductal Adenocarcinoma.

Mutations in the AT-rich interactive domain 1A gene, which encodes a subunit of the Switch/Sucrose nonfermentable chromatin remodeling complex, can result in loss of protein expression and are associated with different cancers. Here, we used immunohistochemistry to investigate the significance of AT-rich interactive domain 1A loss in 73 pancreatic ductal adenocarcinoma cases with paired paracancerous normal pancreatic tissues. The relationship between levels of the AT-rich interactive domain 1A protein product, BAF250a, and clinicopathological parameters in the 73 pancreatic cancer specimens was also analyzed. We found that the expression of AT-rich interactive domain 1A in normal pancreatic tissue was higher than that in tumor tissue. Loss of AT-rich interactive domain 1A expression in pancreatic tumors was associated with tumor differentiation (P = .002) and tumor stage (P = .048). Meanwhile, BAF250a protein levels were not related to lymph node metastasis, distant metastasis, sex, or age and were not associated with survival. Transfection of the pancreatic cancer cell lines AsPC-1 and PANC-1 with small-interfering RNA specific for AT-rich interactive domain 1A resulted in elevated messenger RNA and protein expression levels of B-cell lymphoma-2 (Bcl-2), CyclinD1, and Kirsten rat sarcoma viral oncogene (KRAS). The AT-rich interactive domain 1A expression level in the cells was increased following microRNA-31 (miR-31) inhibitor transfection. Our data provide additional evidence that AT-rich interactive domain 1A might function as a tumor suppressor gene in pancreatic carcinogenesis.

ARID1A Expression is Down-Regulated by Oxidative Stress in Endometriosis and Endometriosis-Associated Ovarian Cancer.

Oxidative stress is considered an important factor in the development of endometriosis, including its malignant transformation. Previous studies have found that AT-rich interactive domain 1A (ARID1A), a tumor suppressor gene, is frequently mutated and inactivated in endometriosis-associated ovarian cancer (EAOC), and such a change in this gene is considered an early event in malignant transformation. We observed oxidative stress status by measuring the activity of the antioxidant enzyme manganese superoxide dismutase (MnSOD), malondialdehyde (MDA), and ARID1A gene expression in tissue samples from patients with endometriosis, EAOC, or non–endometriosis-associated ovarian cancer (non-EAOC). We also induced oxidative stress in the cultured cells from patients with primary endometriosis by adding H2O2 and tested for any alteration of ARID1A gene expression based on different H2O2 concentrations. The results showed that MnSOD activity in endometriosis and EAOC was lower than in non-EAOC, but MDA levels were higher. This study also showed that oxidative stress reduced ARID1A gene expression.

Genome-wide analysis of gynecologic cancer: The Cancer Genome Atlas in ovarian and endometrial cancer.

Cancer typically develops due to genetic abnormalities, but a single gene abnormality cannot completely account for the onset of cancer. The Cancer Genome Atlas (CGA) project was conducted for the cross-sectional genome-wide analysis of numerous genetic abnormalities in various types of cancer. This approach has facilitated the identification of novel AT-rich interaction domain 1A gene mutations in ovarian clear cell carcinoma, frequent tumor protein 53 (TP53) gene mutations in high-grade ovarian serous carcinoma, and Kirsten rat sarcoma and B-rapidly accelerated fibrosarcoma proto-oncogene, serine/threonine kinase gene mutations in low-grade ovarian serous carcinoma. Genome-wide analysis of endometrial cancers has led to the establishment of four subgroups: Polymerase ultramutated, microsatellite instability hypermutated, genome copy-number low and genome copy-number high. These results may facilitate the improvement of the prediction of patient prognosis and therapeutic sensitivity in various types of gynecologic cancer. The enhanced use of currently available therapeutic agents and the development of novel drugs may be facilitated by the novel classification of ovarian cancer based on TP53 mutations, the efficacy of poly (ADP-ribose) polymerase inhibitors for tumors with breast cancer 1/2 mutations and the effect of phosphoinositide-3-kinase (PI3K)/mammalian target of rapamycin inhibitors for tumors with mutations in the PI3K/protein kinase B signaling pathway. Important results have been revealed by genome-wide analyses; however, the pathogenic underlying mechanisms of gynecologic cancer will require further studies and multilateral evaluation using epigenetic, transcriptomic and proteomic analyses, in addition to genomic analysis.

ARID1A gene silencing reduces the sensitivity of ovarian clear cell carcinoma to cisplatin.

In ovarian clear cell carcinoma (OCCC), the mutation rate of the AT-rich interaction domain 1A (ARID1A) gene is 46-57%. However, the effects of ARID1A gene silencing by small interfering RNA (siRNA) on the sensitivity of OCCC to cisplatin have not been investigated. Thus, this study aimed to elucidate the association between ARID1A gene silencing and drug resistance in OCCC. Three pairs of ARID1A gene siRNA fragments (siRNA-1, siRNA-2 and siRNA-3) were designed and transiently transfected into ES2 OCCC cells using RNAi Max reagent. Western blotting results demonstrated that the transfection reduced ARID1A protein expression levels, with the siRNA-3 group having the lowest levels. The IC50 value, determined using a Cell Counting kit-8 assay, was significantly increased by siRNA-3 transfection compared with that in blank control and negative control groups. The cell survival rate following treatment with 50 µM cisplatin for 48 h was significantly increased in the siRNA-3 group compared with the blank control and negative control groups. Flow cytometric analysis revealed that the apoptosis rate for cisplatin-treated cells was significantly lower in cells with siRNA-3 transfection than in those without, and the apoptosis rate in siRNA-3-transfected cells was lower than that in the negative control group. Western blot analysis showed that the expression level of AKT in cisplatin-treated cells was significantly decreased compared with that in the negative control group, and the AKT expression level in cisplatin-treated cells was significantly higher with siRNA-3 transfection than without. Therefore, the results demonstrated that ARID1A siRNA efficiently decreased ARID1A expression, which reduced cisplatin chemosensitivity and cell apoptosis in ES2 OCCC cells via the regulation of AKT expression.

Loss of ARID1A expression predicts poor survival prognosis in gastric cancer: a systematic meta-analysis from 14 studies.

The chromatin remodeling gene, AT-rich interactive domain 1A gene (ARID1A), frequently mutates inactively in gastric cancer (GC). However, its prognostic value remains controversial. To address this issue, a comprehensive meta-analysis was performed. Studies published until March 2016 were systematically searched. A total of 15 cohorts from 14 literatures involving 3183 patients were subjected to this meta-analysis. The pooled data showed that ARID1A expression loss predicted poor overall survival (OS) in GC (Hazard Ratio (HR) = 1.60; 95% Confidence Interval (CI) = 1.40–1.81; P < 0.001), with low heterogeneity among these studies (I2 = 21.5%; P = 0.214). Stratification analyses revealed that ARID1A expression loss was associated with poor OS in Asians (HR = 1.65, 95% CI = 1.44–1.89), proportion of proximal disease ≤30% subgroup (HR = 1.80, 95% CI = 1.36–2.38) and Epstein-Barr virus (EBV) (+) > 5% subgroup (HR = 1.59, 95% CI = 1.18–2.15). The robust results were suggested by sensitivity analyses and no evidence of significant publication bias was detected. This study demonstrated a significant relationship between deletion of ARID1A expression and poor OS in GC. Moreover, ethnicity, tumor location and EBV infection status might be potential key factors influencing this correlation.