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  1. Sham NFR, Hasani NAH, Hasan N, Karim MKA, Fuad SBSA, Hasbullah HH, et al.
    Sci Rep, 2023 Feb 22;13(1):3108.
    PMID: 36813833 DOI: 10.1038/s41598-023-29925-x
    Cancer recurrence is often associated with the acquisition of radioresistance by cancer tissues due to failure in radiotherapy. The underlying mechanism leading to the development of acquired radioresistance in the EMT6 mouse mammary carcinoma cell line and the potential pathway involved was investigated by comparing differential gene expressions between parental and acquired radioresistance cells. EMT6 cell line was exposed to 2 Gy/per cycle of gamma-ray and the survival fraction between EMT6-treated and parental cells was compared. EMT6RR_MJI (acquired radioresistance) cells was developed after 8 cycles of fractionated irradiation. The development of EMT6RR_MJI cells was confirmed with further irradiation at different doses of gamma-ray, and both the survival fraction and migration rates were measured. Higher survival fraction and migration rates were obtained in EMT6RR_MJI cells after exposure to 4 Gy and 8 Gy gamma-ray irradiations compared to their parental cells. Gene expression between EMT6RR_MJI and parental cells was compared, and 16 genes identified to possess more than tenfold changes were selected and validated using RT-PCR. Out of these genes, 5 were significantly up-regulated i.e., IL-6, PDL-1, AXL, GAS6 and APCDD1. Based on pathway analysis software, the development of acquired radioresistance in EMT6RR_MJI was hypothesized through JAK/STAT/PI3K pathway. Presently, CTLA-4 and PD-1 were determined to be associated with JAK/STAT/PI3K pathway, where both their expressions were significantly increased in EMT6RR_MJI compared to parental cells in the 1st, 4th and 8th cycle of radiation. As a conclusion, the current findings provided a mechanistic platform for the development of acquired radioresistance in EMT6RR_MJI through overexpression of CTLA-4 and PD-1, and novel knowledge on therapeutic targets for recurrent radioresistant cancers.
    Matched MeSH terms: CTLA-4 Antigen*
  2. Idris ZM, Yazdanbakhsh M, Adegnika AA, Lell B, Issifou S, Noordin R
    Genet Test Mol Biomarkers, 2012 Jun;16(6):488-92.
    PMID: 22288822 DOI: 10.1089/gtmb.2011.0209
    Urinary schistosomiasis is caused by the digenetic trematode Schistosoma haematobium, characterized by accumulation of eggs in the genitourinary tract. Cytotoxic T-lymphocyte antigen 4 (CTLA-4) can play an important role in parasitic infection due to its major role as a negative regulator of T-cell activation and proliferation. This study was performed in patients with schistosomiasis and healthy controls to analyze the allele and genotype frequencies of four CTLA-4 gene polymorphisms. The CTLA-4 gene was amplified using Taqman real-time polymerase chain reaction, and allele and genotypes of 49 patients with schistosomiasis were analyzed using allelic discrimination analysis followed by subsequent direct sequencing. The results were compared with healthy control subjects. The frequencies of CTLA-4 rs733618 A allele at position -1722 (p=0.001), rs11571316 C allele at position -1577 (p<0.001), and rs231775 A allele at position +49 (p=0.002) in the patient group were significantly higher than the control group. The rs733618 AA genotype (p=0.001), rs11571316 CC genotype (p<0.001), and rs231775 AA genotype (p=0.007) were also significantly overrepresented. Meanwhile, rs733618 AG genotype (p=0.001), rs11571316 CT genotype (p=0.02), and rs231775 GG genotype (p=0.029) were significantly decreased in the patients with schistosomiasis, as compared with the controls. No significant difference was observed in both allele and genotype of rs16841252. The results of this study suggest that the rs733618, rs11571316, and rs231775 polymorphisms in the CTLA-4 gene may influence susceptibility to schistosomiasis infection in the Gabonese children.
    Matched MeSH terms: CTLA-4 Antigen/genetics*
  3. Fahmy O, Khairul-Asri MG, Stenzl A, Gakis G
    Med Hypotheses, 2016 Jul;92:57-8.
    PMID: 27241256 DOI: 10.1016/j.mehy.2016.04.037
    Although intravesical instillation of Bacille-Calmette-Guerin (BCG) immunotherapy was approved many decades ago as a first line therapy for intermediate to high-risk non-muscle invasive bladder cancer, its long-term efficacy is still arguable as a proportion of up to 30-40% of patients will develop recurrence or progression of their disease. Based on currently available data on the clinical application of checkpoint inhibitors in solid tumors, the mucosa-associated lymphoid tissue seems to be a main target for anti-CTLA-4 antibodies. In this manuscript we hypothesize that the combination of anti-CTLA-4 therapy with BCG might enhance the immune activity in the bladder submucosal tissue, and subsequently, improve oncological outcomes of NMIBC.
    Matched MeSH terms: CTLA-4 Antigen/antagonists & inhibitors*; CTLA-4 Antigen/chemistry
  4. Nor Aini Lubis, Mhd Zain, Mohd Nasharudin, Razak, Mariatulqabtiah, Abdul Razak
    MyJurnal
    Cervical cancer is one of the leading causal cancer-related fatalities in the world. Cervical cancer patients can be treated by conventional treatment such as surgery, radiotherapy, chemotherapy, medications and combination treatments. Currently, more targeted treatments are being developed to cure cervical cancer. The treatments include immunotherapy, virotherapy and gene therapy which will be discussed in this paper. In immunotherapy, the synergy of CTLA-4 suppression and PD-1/PDL-1 immune checkpoint inhibition targeting their corresponding pathways enhanced the human immune system resulting a promising treatment effects. Oncolytic viruses such as Newcastle disease virus selectively infect and kill cancerous cells/tissues without harming normal cells/tissues. This character has made them a potential modality in combating cancer which popularly known as oncolytic virotherapy. Gene therapy delivers modified genetic materials to the target cancer cells via viral and non-viral vectors. It is used to target the abnormal gene, to increase cells’ susceptibility towards drugs or conventional therapy, to induce tumour cells apoptosis, to enhance tumour cell immunogenicity recognition and to inhibit the oncogene expression. The objective of this minireview is to add to the general knowledge on aforementioned therapeutic strategies against cervical cancer.
    Matched MeSH terms: CTLA-4 Antigen
  5. Fahmy O, Khairul-Asri MG, Stenzl A, Gakis G
    Clin. Exp. Metastasis, 2016 10;33(7):629-35.
    PMID: 27380916 DOI: 10.1007/s10585-016-9807-9
    For many decades, no significant improvements could be achieved to prolong the survival in metastatic bladder cancer. Recently, systemic immunotherapy with checkpoint inhibitors (anti-PD-L1/anti-CTLA-4) has been introduced as a novel treatment modality for patients with metastatic bladder cancer. We conducted a systematic review according to the PRISMA statement for data published on the clinical efficacy of checkpoint inhibitors in metastatic bladder cancer. Clinical efficacy of anti PD-L1 therapy was investigated in prospective trials in a total of 155 patients. Patients with positive expression for PD-L1 tended towards better overall response rates (ORR) compared to those with negative expression (34/76 vs 10/73, 45 vs 14 %; p = 0.21). Among patients with PD-L1 positive tumors, those with non-visceral metastases exhibited significantly higher ORR compared to those with visceral metastases (82 vs 28 %; p = 0.001). For anti-CTLA4 therapy, there were no data retrievable on clinical efficacy. Although data on clinical efficacy of checkpoint inhibitors in metastatic bladder cancer are currently limited, the efficacy of these drugs might depend mainly on the metastatic volume and immune system integrity. Patients with PD-L1 positive tumors and non-visceral metastases seem to derive the highest benefit from therapy.
    Matched MeSH terms: CTLA-4 Antigen/antagonists & inhibitors*; CTLA-4 Antigen/genetics
  6. Ahmed RH, Huri HZ, Al-Hamodi Z, Salem SD, Al-Absi B, Muniandy S
    PLoS One, 2016;11(4):e0154369.
    PMID: 27111895 DOI: 10.1371/journal.pone.0154369
    BACKGROUND: Genetic polymorphisms of the Dipeptidyl Peptidase 4 (DPP4) gene may play a role in the etiology of type 2 diabetes mellitus (T2DM). This study aimed to investigate the possible association of single nucleotide polymorphisms (SNPs) of the DPP4 gene in Malaysian subjects with T2DM and evaluated whether they had an effect on the serum levels of soluble dipeptidyl peptidase 4 (sDPP-IV).

    METHOD: Ten DPP4 SNPs were genotyped by TaqMan genotyping assays in 314 subjects with T2DM and 235 controls. Of these, 71 metabolic syndrome (MetS) subjects were excluded from subsequent analysis. The odds ratios (ORs) and their 95% confidence interval (CIs) were calculated using multiple logistic regression for the association between the SNPs of DPP4 and T2DM. In addition, the serum levels of sDPP-IV were investigated to evaluate the association of the SNPs of DPP4 with the sDPP-IV levels.

    RESULTS: Dominant, recessive, and additive genetic models were employed to test the association of DPP4 polymorphisms with T2DM, after adjusting for age, race, gender and BMI. The rs12617656 was associated with T2DM in Malaysian subjects in the recessive genetic model (OR = 1.98, p = 0.006), dominant model (OR = 1.95, p = 0.008), and additive model (OR = 1.63, p = 0.001). This association was more pronounced among Malaysian Indians, recessive (OR = 3.21, p = 0.019), dominant OR = 3.72, p = 0.003) and additive model (OR = 2.29, p = 0.0009). The additive genetic model showed that DPP4 rs4664443 and rs7633162 polymorphisms were associated with T2DM (OR = 1.53, p = 0.039), and (OR = 1.42, p = 0.020), respectively. In addition, the rs4664443 G>A polymorphism was associated with increased sDPP-IV levels (p = 0.042) in T2DM subjects.

    CONCLUSIONS: DPP4 polymorphisms were associated with T2DM in Malaysian subjects, and linked to variations in sDPP-IV levels. In addition, these associations were more pronounced among Malaysian Indian subjects.

    Matched MeSH terms: CTLA-4 Antigen/genetics
  7. Peng S, Ying AF, Tai BC, Soo RA
    Transl Lung Cancer Res, 2020 Aug;9(4):1124-1137.
    PMID: 32953491 DOI: 10.21037/tlcr-20-246
    Background: We conducted a meta-analysis to assess the efficacy of immune checkpoint inhibitors (ICIs) (PD-1/L1 and CTLA-4 inhibitors) in first and subsequent lines in East Asians and non-East Asians.

    Methods: We searched PubMed-MEDLINE, Embase and Scopus, from inception to 20 Sep 2019, and reviewed major conferences' abstracts, for randomised controlled trials of ICI in advanced-stage NSCLC (Stage IIIB or IV) without EGFR mutation that reported hazard ratios (HRs) stratified by geographical region including the region "Asia" or "East Asia". The primary outcome measures were overall survival (OS) and progression-free survival (PFS). The pooled HR and its 95% confidence interval (CI) for OS and PFS in East Asians and non-East Asians were calculated using a random effect model and the difference compared using an interaction test.

    Results: A total of 5,465 patients from 7 randomised controlled trials involving CTLA-4 and/or PD-1/L1 inhibitors were included, with 1,740 (32%) East Asians and 3,725 (68%) non-East Asians. ICI was associated with an improvement in OS and PFS for both East Asian (OS HR, 0.74; 95% CI, 0.65-0.85; PFS HR, 0.56; 95% CI, 0.40-0.79) and non-East Asian patients (OS HR, 0.78; 95% CI, 0.72-0.85; PFS HR, 0.69; 95% CI, 0.56-0.85), with no significant difference between the two groups (Pinteraction=0.55 for OS; Pinteraction=0.33 for PFS). Subgroup analyses showed a statistically significant superior PFS (but not OS) for East Asians than non-East Asians in trials that used immune checkpoint inhibitor in the first-line treatment (Pinteraction=0.02). No significant regional difference was found in further subgroups of pure ICI and combination of ICI with chemotherapy.

    Conclusions: There is no significant difference in response to ICI between East Asians and non-East Asians with advanced stage NSCLC, and the statistically significant subgroup difference in PFS in the first line use of ICI may not be clinically significant.

    Matched MeSH terms: CTLA-4 Antigen
  8. AL-Battawi, S., Hameed, S., Ng, E.S.C., Amini, F.
    JUMMEC, 2018;21(2):45-52.
    MyJurnal
    Graft-versus-host Disease (GVHD) is the main cause of morbidity and mortality after allogeneic hematopoietic
    stem cell transplantation (alloHSCT). In spite of immune-suppressive prophylaxis, most survivors suffer from
    acute and chronic GVHD (aGVHD and cGVHD). The outcome of alloHSCT may be affected by the presence of
    single nucleotide polymorphism (SNP) in non-HLA genes including those involved in innate immune responses.
    This study aimed to evaluate the impact of cytotoxic T-lymphocyte antigen-4 (CTLA-4) and caspase recruitment
    domain 15 (NOD2/CARD15) gene polymorphisms on the incidence and severity of aGVHD and cGVHD following
    alloHSCT. A structured literature review was carried out using various keywords and MESH terms such as
    stem cell transplantation, allogenic haematopoietic stem cell transplantation, GVHD, and non-HLA gene
    polymorphism, in PubMed, Google Scholar and Cochrane Database. A total of 8 studies that met inclusion
    criteria (English publications from 2006 to 2017) were included. Ten SNPs in CTLA-4 gene and three SNPs in
    NOD2/CARD15 gene were tested in patients with underlying haematological malignancies. Four studies tested
    the SNPs of CTLA-4 gene and two were found to have an association with CTLA-4 SNPs (rs3087243, rs231775)
    and increased incidence of aGVHD. The other four studies tested the SNPs of NOD2/CARD15 gene and one
    found an association between SNP13 and increased incidence of aGVHD. None of these eight studies found
    any effect on severity of GVHD. In conclusion, two SNPs in CTLA-4 and one SNP in NOD2/CARD15 increased
    the incidence of aGVHD but not its severity. The higher incidence of aGVHD in studies with larger sample size
    could support the impact of SNPs in the outcome of alloHSCT. However, due to the heterogeneity of studies in
    regard to the age of patients and donor, and conditioning regimen, it is difficult to draw a definite conclusion.
    Matched MeSH terms: CTLA-4 Antigen
  9. Chua KH, Puah SM, Chew CH, Tan SY, Lian LH
    Ann Hum Biol, 2010 Apr;37(2):274-80.
    PMID: 19951233 DOI: 10.3109/03014460903325185
    In this study, we investigated the polymorphisms of the exon 1 (+49A/G), promoter sites (-1722T/C, -1661A/G, -318C/T), and 3'-untranslated region (3'-UTR) (+6230 A/G) of the CTLA-4 gene in systemic lupus erythematosus (SLE) affected patients. Polymerase chain reaction-restriction fragment length polymorphism was used to determine genotypes of these five markers in 130 SLE patients and 130 healthy controls. Of the five tested polymorphisms, there was no statistical significant difference between the genotypic and allelic frequencies of patients with SLE and controls. Hence, we propose that the CTLA-4 gene does not play a major role in the genetic susceptibility to the development of SLE in the Malaysian population.
    Matched MeSH terms: CTLA-4 Antigen
  10. Kampan NC, Madondo MT, McNally OM, Stephens AN, Quinn MA, Plebanski M
    Front Immunol, 2017;8:1482.
    PMID: 29163543 DOI: 10.3389/fimmu.2017.01482
    Background: Epithelial ovarian cancer (EOC) remains a highly lethal gynecological malignancy. Ascites, an accumulation of peritoneal fluid present in one-third of patients at presentation, is linked to poor prognosis. High levels of regulatory T cells (Tregs) in ascites are correlated with tumor progression and reduced survival. Malignant ascites harbors high levels of Tregs expressing the tumor necrosis factor receptor 2 (TNFR2), as well as pro-inflammatory factors such as interleukin 6 (IL-6) and tumor necrosis factor (TNF). IL-6 is also associated with poor prognosis. Herein, we study the effect of IL-6 and TNF present in ascites on the modulation of TNFR2 expression on T cells, and specifically Tregs.

    Methods: Ascites and respective peripheral blood sera were collected from 18 patients with advanced EOC and soluble biomarkers, including IL-6, sTNFR2, IL-10, TGF-β, and TNF, were quantified using multiplexed bead-based immunoassay. Peripheral blood mononuclear cells (PBMC) from healthy donors were incubated with cell-free ascites for 48 h (or media as a negative control). In some experiments, IL-6 or TNF within the ascites were neutralized by using monoclonal antibodies. The phenotype of TNFR2(+) Tregs and TNFR2(-) Tregs were characterized post incubation in ascites. In some experiments, cell sorted Tregs were utilized instead of PBMC.

    Results: High levels of immunosuppressive (sTNFR2, IL-10, and TGF-β) and pro-inflammatory cytokines (IL-6 and TNF) were present in malignant ascites. TNFR2 expression on all T cell subsets was higher in post culture in ascites and highest on CD4(+)CD25(hi)FoxP3(+) Tregs, resulting in an increased TNFR2(+) Treg/effector T cell ratio. Furthermore, TNFR2(+) Tregs conditioned in ascites expressed higher levels of the functional immunosuppressive molecules programmed cell death ligand-1, CTLA-4, and GARP. Functionally, TNFR2(+) Treg frequency was inversely correlated with interferon-gamma (IFN-γ) production by effector T cells, and was uniquely able to suppress TNFR2(+) T effectors. Blockade of IL-6, but not TNF, within ascites decreased TNFR2(+) Treg frequency. Results indicating malignant ascites promotes TNFR2 expression, and increased suppressive Treg activity using PBMC were confirmed using purified Treg subsets.

    Conclusion: IL-6 present in malignant ovarian cancer ascites promotes increased TNFR2 expression and frequency of highly suppressive Tregs.

    Matched MeSH terms: CTLA-4 Antigen
  11. Yong YK, Saeidi A, Tan HY, Rosmawati M, Enström PF, Batran RA, et al.
    Front Immunol, 2018;9:472.
    PMID: 29616020 DOI: 10.3389/fimmu.2018.00472
    Mucosal-associated invariant T (MAIT) cells, defined as CD161++TCR iVα7.2+ T cells, play an important role in the innate defense against bacterial infections, and their functionality is impaired in chronic viral infections. Here, we investigated the frequency and functional role of MAIT cells in chronic hepatitis B virus (HBV) infection. The peripheral CD3+CD161++TCR iVα7.2+ MAIT cells in chronic HBV-infected patients and healthy controls were phenotypically characterized based on CD57, PD-1, TIM-3, and CTLA-4, as well as HLA-DR and CD38 expression. The frequency of MAIT cells was significantly decreased among chronic HBV-infected individuals as compared to controls. Expression of CD57, PD-1, CTLA-4, as well as HLA-DR and CD38 on MAIT cells was significantly elevated in chronic HBV-infected individuals relative to controls. The percentage of T cell receptor (TCR) iVα7.2+ CD161+ MAIT cells did not correlate with HBV viral load but inversely with HLA-DR on CD4+ T cells and MAIT cells and with CD57 on CD8+ T cells suggesting that decrease of MAIT cells may not be attributed to direct infection by HBV but driven by HBV-induced chronic immune activation. The percentage and expression levels of PD-1 as well as CTLA-4 on MAIT cells inversely correlated with plasma HBV-DNA levels, which may suggest either a role for MAIT cells in the control of HBV infection or the effect of HBV replication in the liver on MAIT cell phenotype. We report that decrease of TCR iVα7.2+ MAIT cells in the peripheral blood and their functions were seemingly impaired in chronic HBV-infected patients likely because of the increased expression of PD-1.
    Matched MeSH terms: CTLA-4 Antigen
  12. Idris ZM, Miswan N, Muhi J, Mohd TA, Kun JF, Noordin R
    Hum Immunol, 2011 Jul;72(7):607-12.
    PMID: 21513760 DOI: 10.1016/j.humimm.2011.03.017
    Lymphatic filariasis (LF) is a parasitic disease caused by threadlike worms of the Brugia and Wuchereria species that live in the human lymphatic system. Regulatory T cells (Tregs) may play a key role in the pathogenesis of LF, and cytotoxic T-lymphocyte antigen-4 (CTLA4) expressed by Tregs is a potential candidate gene because it modulates T-cell activation. A case-control study was performed to establish a potential association of 5 CTLA4 gene promoter single nucleotide polymorphisms (SNPs; rs733618, rs11571316, rs5742909, rs231775, and rs16840252) with the occurrence of LF in an East Malaysian population (320 LF-infected individuals and 150 healthy controls). Polymorphisms were evaluated using TaqMan real-time polymerase chain reaction followed by direct sequencing. LF carriers of the rs733618 AG genotypes (p = 0.02) and those with combined minor allele G carriers (AG + GG; p = 0.01) exhibited a significantly decreased risk for LF. Among the asymptomatic amicrofilaremic cases, positive associations were reported for all genotypes and variants of rs733618 with odds ratios (ORs) ranging from 0.27 to 0.45. In the asymptomatic microfilaremic cases, marker rs231775 exhibited a significant decreased risk, with ORs ranging from 0.50 to 0.57. The study has identified SNPs in the CTLA4 promoter gene that may be functionally linked with susceptibility to LF.
    Matched MeSH terms: CTLA-4 Antigen
  13. Lim A, Tan D, Price P, Kamarulzaman A, Tan HY, James I, et al.
    AIDS, 2007 Jul 31;21(12):1525-34.
    PMID: 17630546
    To examine the relationships between blood CD4 natural regulatory T (Treg) cells, plasma HIV RNA level, CD4 T-cell count and immune activation in untreated HIV-infected patients and immunodeficient patients beginning antiretroviral therapy (ART), using a novel phenotype to define Treg cells (CD25CD127CD4). Data were compared with established Treg cell markers (FoxP3, CTLA-4 and GITR).
    Matched MeSH terms: CTLA-4 Antigen
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