Effect of p53 mutation mediated by APOBEC3B on NSCLC metastasis / 中国医师杂志

Objective APOBEC3B (A3B) is an important member of the apolipoprotein B mRNA editing enzyme catalytic polypeptide (APOBEC) family.This study aimed to investigate its important role in the metastasis of small cell lung cancer (NSCLC).Methods The statistical relationship between A3 B and clinicopathological data was analyzed in 249 cases of NSCLC.Sanger sequencing was used to detect mutations in exon 5,6,7 and 8 of P53 in 74 cases of lung cancer.A3B overexpression cell line was constructed in human lung adenocarcinoma cells HCC827 to observe the change of cell migration and metastasis capacity.Results A3B was highly expressed in NSCLC tissues compared with normal lung tissues.The expression of A3B was closely related to the lymph node metastasis of NSCLC and the mutation rate of p53 was positively correlated with the expression of A3B.In vitro experiment,it showed enhanced migration and increased metastatic potential in cells after overexpression of A3B.Conclusions A3B-mediated mutations in P53 may play a key role in the metastasis of NSCLC.

Expression of activation-induced cytidine deaminase in renal tissues of patients with systemic lupus erythematosus and its clinical significance / 第二军医大学学报

Objective To explore the expression of activation-induced cytidine deaminase (AICDA) in renal tissues of patients with systemic lupus erythematosus (SLE) and its clinical significance. Methods The renal biospy tissues from 73 patients with SLE and 36 patients with primary membranous nephropathy, who underwent biopsy between Mar. 2013 to Jun. 2017 in Central South University Xiangya School of Medicine Affiliated Haikou Hospital, were collected. Immunohistochemical method was used to detect the expression of AICDA in renal tissues. The correlations between the expression level of AICDA and the clinicopathological parameters, including pathological classification, system damage, SLE disease activity index (DAI) score and treatment outcome of SLE patients were analyzed. Results The expression level of AICDA in renal tissues of SLE patients was significantly higher than that of primary membrane nephropathy patients (6.12±2.47 vs 3.33±1.91, P0.05). The expression levels of AICDA were significantly higher in renal tissues of SLE patients with oral ulcer, interstitial pneumonia, nervous system damage, arthritis, blood system damage or serositis than those in the patients without above symptoms (7.02±2.14 vs 4.17±1.97, 7.86±2.39 vs 4.98±1.76, 9.83±1.34 vs 5.39±1.92, 6.88±2.04 vs 2.93±1.21, 7.51±1.81 vs 3.70±1.23, and 7.29±2.33 vs 5.34±2.29; all P0.05). Conclusion AICDA is related to the occurrence and development of SLE, and it is expected to bring new targets for the treatment of SLE.

The influence of genetic variation of cytidine deaminase on hand-foot syndrome among colorectal cancer patients treated with capecitabine-based adjuvant chemother-apy regimens / 中国肿瘤临床

Objective:To investigate the association between grade 3 hand-foot syndrome(HFS)in colorectal cancer(CRC)patients treated with capecitabine and variation of cytidine deaminase(CDA)genes.Methods:The polymorphisms of the key gene CDA in-volved in capecitabine metabolism were genotyped and 149 CRC patients were included in this study.The association between these polymorphisms and susceptibility to HFS were analyzed.Additionally,peripheral blood mononuclear cells(PBMCs)of 91 CRC patients were collected for mRNA expression analysis, and the levels of mRNA expression according to different CDA genotypes were com-pared.Results:The prevalence of the polymorphism-451G>A,which is located in the promoter region of CDA,were correlated with HFS. The results were as follows: GG genotype, 109 cases (73.15%); GA genotype, 38 cases (25.50%); and AA genotype, 2 cases (1.36%).The minor allele frequency of-451G>A was 0.14.The distribution of the three genotypes were in accordance with Hardy-Weinberg Equilibrium(P=0.516).Logistic analysis indicated that GA/AA genotypes were associated with grade 3 HFS(odds ratio=2.53, P=0.011).Additionally,another insert polymorphism-33delC located in the promoter region of CDA was in linkage disequilibrium with-451G>A (D'=0.92). Of the 91 PBMC mRNA expression analyses, the GA/AA genotype of-451G>A was associated with higher CDA mRNA expression compared with GG genotypes(4.01±0.53 vs.3.13±0.61,P<0.001).Conclusions:The polymorphism-451G>A of CDA may influence occurance of grade 3 HFS induced by capecitabine by influencing CDA mRNA expression.

Construction of Mycobacterium tuberculosis cdd knockout and evaluation of invasion and growth in macrophages

Cytidine deaminase (MtCDA), encoded by cdd gene (Rv3315c), is the only enzyme identified in nucleotide biosynthesis pathway of Mycobacterium tuberculosis that is able to recycle cytidine and deoxycytidine. An M. tuberculosis knockout strain for cdd gene was obtained by allelic replacement. Evaluation of mRNA expression validated cdd deletion and showed the absence of polar effect. MudPIT LC-MS/MS data indicated thymidine phosphorylase expression was decreased in knockout and complemented strains. The cdd disruption does not affect M. tuberculosis growth both in Mid- dlebrook 7H9 and in RAW 264.7 cells, which indicates that cdd is not important for macrophage invasion and virulence.

Application of Sanger sequencing technology in detection of gemcitabine resistance sensitive gene CDA / 国际检验医学杂志

Objective To analyze the polymorphic site mutation of gemcitabine resistant sensitive gene cytidine deaminase (CDA),and to investigate the applicability of the Sanger detection technology in clinical sample detection with the real-time fluores-cence quantitative PCR as the reference.Methods The peripheral blood samples from 255 cases of stage ⅢB to Ⅳ non small-cell lung cancer(NSCLC)were randomly selected for extracting DNA.The G208A and A79C mutation situation of CDA gene was re-spectively detected by qPCR and Sanger sequencing technology.Results The success rate for detecting the CDA gene mutation in peripheral blood sample in 255 cases of stage ⅢB and Ⅳ NSCLC were 98.04%(250/255)by the Sanger sequencing method and 97.25%(248/255)by qPCR.With the qPCR as the reference,the sensitivity and specificity of Sanger sequencing method was 92.50% and 99.52% respectively.All mutation types detected by two methods were fully consistent.Conclusion Adopting the Sanger sequencing method can effectively detect drug resistance gene CDA mutation,realizes the mutation typing,can accurately, high throughput and efficiently detect CDA mutation site,which provides an effective detection method for gemcitabine sensitive medication of NSCLC.

Epstein-Barr virus infection of infants: implications of early age of infection on viral control and risk for Burkitt lymphoma / Infección en lactantes por virus de Epstein-Barr: implicaciones de la infección a temprana edad sobre el control viral y el riesgo de linfoma de Burkitt

Since its first description by Denis Burkitt, endemic Burkitt's lymphoma (BL), the most common childhood cancer in sub-Saharan Africa, has led scientists to search for clues to the origins of this malignancy. The discovery of Epstein-Barr virus (EBV) in BL cells over 50 years ago led to extensive sero-epidemiology studies and revealed that rather than being a virus restricted to areas where BL is endemic, EBV is ubiquitous in the world's population with an estimated greater than 90% of adults worldwide infected. A second pathogen, Plasmodium falciparum (P. falciparum) malaria is also linked to BL. In this review, we will discuss recent studies that indicate a role for P. falciparum malaria in dysregulating EBV infection, and increasing the risk for BL in children living where P. falciparum malaria transmission is high.

Desde la primera descripción por Denis Burkitt, el linfoma de Burkitt (LB) endémico -el tipo de cáncer pediátrico más común en el África subsahariana- ha guiado a los científicos a investigar este padecimiento en la búsqueda de claves para entender sus orígenes. El descubrimiento desde hace 50 años del virus de Epstein-Barr (VEB) en el LB ha conducido a extensos estudios sero-epidemiológicos y ha revelado que, más que ser un virus restringido a áreas donde el LB es endémico, el VEB es ubicuo en la población mundial, con un estimado mayor del 90% de adultos infectados a escala global. Un segundo agente patógeno se ha ligado al LB, el Plasmodium falciparum (P. falciparum) malaria. En esta revisión se discuten los estudios recientes que indican el papel de P. falciparum malaria en la desregulación de la infección por VEB y en el aumento del riego del LB en niños que viven en regiones con alta transmisión de P. falciparum malaria.

Influence of single nucleotide polymorphisms of CDA in prognosis of advanced non-small cell lung cancer patients treated with gemcitabine / 吉林大学学报(医学版)

Objective:To investigate the influence of single nucleotide polymorphisms (SNP ) of cytidine deaminase (CDA)in the curative effect of gemcitabine,and to clarify the correlation of CDA SNP with the clinical prognosis of the advanced non-small cell lung cancer (NSCLC)patients.Methods:CDA 79A>C gene was detected by Sequenom Massarray Genotype System among 93 patients with advanced NSCLC who received chemotherapy of gemcitabine.The associations between CDA 79A>C polymorphisms and progression free survival (PFS)and overall survival (OS)were estimated using Kaplan-meier methods and Log-rank test for univariate analysis, and COX proportional hazards model was used for multivariate analysis.Results:There was no significant correlation between the CDA 79A>C SNPs with the clinical and pathological characteristics of NSCLC patients.The median PFS in the patients with wild genotype A/A was 9.3 months, while the median PFS in the patients with mutant genotype A/C and C/C was 11 months;there was no significant difference between them (P=0.061).The median OS in the patients with wild genotype A/A was 2 1.7 months, and the median OS of the patients with mutant genotype was 22.1 months;there was no significant difference between them (P=0.513).Conclusion:CDA 79A>C SNPs can prolong the PFS of the NSCLC patients,but it does not affect the OS of the patients.

Expression of activation-induced cytidine deaminase gene in leukemia / 白血病·淋巴瘤

Objective To investigate the characteristics of activation-induced cytidine deaminase (AID) expression level in de novo acute leukemia (AL) patients, chronic myeloid leukemia chronic phase (CML-CP), chronic myeloid leukemia blastic crisis (CML-BC) patients and leukemia cell lines. Methods The expression level of AID mRNA was measured in 89 cases of newly-diagnosed acute lymphoblastic leukemia (ALL) patients, 79 cases of de novo acute myeloid leukemia (AML) patients, 5 cases of CML-BC patients, 5 cases of CML-CP patients and leukemia cell lines NB4, THP-1, KG-1, Raji, K562 by real-time quantitative reverse transcriptase polymerase chain reaction (RT-PCR), bone marrow mononuclear cells of 16 normal healthy donors were used as the control group. Results The expression levels of AID mRNA in 89 cases of ALL and 79 cases of AML were 0.006-7 463.175 and 0.005-69.107, the median expression levels were 3.785 and 1.812, the expression level of AID mRNA in the normal control group was 0.146-4.707, and the median expression level was 1.483, respectively. The AID expression levels of ALL, B-ALL, Burkitt leukemia, M4 patients and Raji cells were significantly higher than those of the normal control group (all P <0.05). Nevertheless, the AID mRNA expression levels of M3 patients and NB4, KG-1 cells were lower than those of the normal control group (all P <0.05). Furthermore, the AID mRNA expression levels of K562 cell were strikingly higher than that of the CML-CP patients (P<0.001), so were those of CML-BC, chronic myeloid leukemia myeloid blast crisis (CML-MBC), chronic myeloid leukemia lymphoblastic blast crisis (CML-LBC) patients. Conclusion AID gene shows high expression level in B-ALL, Burkitt leukemia and M4, low expression level in M3 and KG-1 cells, and obvious high expression level in CML-BC.

Correlation analysis between activation-induced cytidine deaminase expression and melanoma invasion, metastasis and prognosis / 中华皮肤科杂志

Objective To explore the relationship between activation-induced cytidine deaminase (AID) expression and melanoma invasion, metastasis and prognosis, and to evaluate the clinical significance of AID. Methods An immunohistochemical study was conducted to detect the expression of AID in paraffin-embedded tissue sections from 80 cases of melanoma and 23 cases of pigmented nevus. The relationship between the expression of AID and clinicopathological and biological features of melanoma was analyzed. Results The expression rate of AID was significantly higher in melanoma than in pigmented nevus tissue specimens(53.75%(43/80)vs. 13.04%(3/23), P 0.05). Of 19 melanoma specimens with BRAF mutations, 17 expressed AID, including all the 15 melanoma specimens with the BRAFV600E mutation. Conclusions AID may induce BRAF mutations in melanoma, participate in melanoma invasion and metastasis, and be correlated with melanoma prognosis.

Apolioprotein B mRNA-editing enzyme catalytic polypeptide family plays a central role in cancer evolution / 第二军医大学学报

The process of carcinogenesis starts in the proinflammatory microenvironment and is abided by Darwinian evolution theory: mutation-selection-adaption; and the genetic basis of this process is the generation and accumulation of somatic mutations. Currently the molecular mechanisms of massive nucleotide alterations and natural selection of mutant cells under environment pressure still remain unclear. The apolioprotein B mRNA-editing enzyme catalytic polypeptide (APOBEC) family of cytidine deaminases, which is transcriptionally induced by proinflammatory cytokine and chemokine, plays important roles in the innate and adaptive immunities of human organism. APOBECs can not only inhibit viral replication but also facilitate the generation of cancer-promoting viral mutants; they can also facilitate the generation of driver mutations in the host genes, thus contribute to the development of cancers. APOBECs, as hallmark enzymes bridging inflammation and cancer, play an important role in cancer evolution.

Research process of apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like in tumors / 肿瘤研究与临床

Apolipoprotein B mRNA editing enzyme,catalytic polypeptide-like (APOBECs) is a group of cytidine deaminases,which represents somewhat unusual protein family that can insert mutations in DNA and RNA as a result of their ability to deaminate cytidine to uridine.APOBECs seem to have diverse roles,such as lipid transport,antigen-driven antibody diversification and acting an innate defense system against retroviruses.In recent years,other functions of APOBECs were identified.Notably,APOBECs can cause host genome mutations and are upregulated in multiple cancers,such as breast,cervix,lung,liver cancers and so on.The researches on APOBEC and its relations with in tumors were reviewed.

Gene therapy of human ovarian carcinoma in vitro / 中国肿瘤临床

To construct a recombinant adenovirus containing CDglyES fusion gene, which can directly inhibit human ovarian cancer cell and indirectly inhibit vascular endothelial cell growth. Methods:We constructed prAdCDglyES using a homolo-gous recombination method in bacteria. The prAdCDglyES was transfected to 293 packaging cells using liposome, in which rAdCDgly-ES was packaged and amplified. MTT was used to observe the proliferation inhibition effect of rAdCDglyES on human ovarian cancer cells and the growth inhibition effect of expressing products of rAdCDglyES on ECV-304. Results:The titer of rAdCDglyES was 1 × 1013.3 TCID50/L, whereas the inhibition rate on human ovarian cancer cell SKOV-3 was (83.1±6.3)%. This result is significantly different from the control rAd-LacZ, which had an inhibition rate of (24.1 ± 13.2)% (P<0.01). The concentrated culture supernatant from cells transfected with rAdCDglyES can inhibit ECV-304 cell proliferation at a rate of (78.7 ± 1.6)%. This rate is significantly different com-pared with that of the control with the same concentration of culture supernatant from cells transfected with rAd-CD, with an effect on ECV-304 cell shown by an inhibition rate of (23.9 ± 9.7)%(P<0.01). Conclusion:The results showed that the recombinant adenovirus rAdCDglyES could inhibit human ovarian cancer cells directly and indirectly.

Expression of IgA class switching gene in tonsillar mononuclear cells in patients with IgA nephropathy / 中华肾脏病杂志

Objec0tive To investigate the molecular mechanism of the mal-production of IgA and IgA1 by tonsillar mononuclear cells (TMCs) in IgA nephropathy (IgAN) patients by measuring the mRNA expression of Iα-Cα germline transcript and the mRNA and protein expression of activated induced cytidine deaminase (AID) in cultured TMCs stimulated with lipopolysaccharide (LPS) or hemolytic streptococcus (HS) in IgAN patients as well as the chronic tonsilitis patients. Methods Twent-seven IgAN patients admitted into our hospital from Jan.2009 to Feb.2010 were enrolled.Twent-seven patients with chronic tonsillitis without renal disease were selected as control.Tonsillar mononuclear cells were isolated by density gradient centrifugation in lymphocyte separation medium.The amount of IgA or IgA1 secreted in the culture supernatants was determined by specific enzyme-linked immunosorbent assay (ELISA).Expressions of Iα-Cα germline transcript and AID mRNA were examined by real-time PCR.The AID protein was determined by Western blot. Results The production of IgA and IgA1 protein,especially the ratio of IgA1/IgA and the expression of AID protein in TMCs were significantly increased in IgAN group compared with chronic tonsillitis group (all P＜0.05).The IgA and IgA1 level of stimulated TMCs were obviously increased in patients with IgAN compared with control group (P＜0.05).And the expressions of Iα-Cα mRNA,AID mRNA and AID protein were up-regulated significantly in stimulated TMCs (all P＜0.05). Conclusions Both LPS and HS can induce the production of IgA and IgA1 and up-regulate the expressions of AID and Iα-Cα in TMCs of IgAN patients.Our results indicate that the TMCs are capable of producing high level of IgA and IgA1 stimulated by LPS or HS,whuch may be due to the　 incression of AID and Iα-Cα.

Activation-induced Cytidine Deaminase in B Cell Immunity and Cancers

Activation-induced cytidine deaminase (AID) is an enzyme that is predominantly expressed in germinal center B cells and plays a pivotal role in immunoglobulin class switch recombination and somatic hypermutation for antibody (Ab) maturation. These two genetic processes endow Abs with protective functions against a multitude of antigens (pathogens) during humoral immune responses. In B cells, AID expression is regulated at the level of either transcriptional activation on AID gene loci or post-transcriptional suppression of AID mRNA. Furthermore, AID stabilization and targeting are determined by post-translational modifications and interactions with other cellular/nuclear factors. On the other hand, aberrant expression of AID causes B cell leukemias and lymphomas, including Burkitt's lymphoma caused by c-myc/IgH translocation. AID is also ectopically expressed in T cells and non-immune cells, and triggers point mutations in relevant DNA loci, resulting in tumorigenesis. Here, I review the recent literatures on the function of AID, regulation of AID expression, stability and targeting in B cells, and AID-related tumor formation.

Activation-induced Cytidine Deaminase in B Cell Immunity and Cancers

Activation-induced cytidine deaminase (AID) is an enzyme that is predominantly expressed in germinal center B cells and plays a pivotal role in immunoglobulin class switch recombination and somatic hypermutation for antibody (Ab) maturation. These two genetic processes endow Abs with protective functions against a multitude of antigens (pathogens) during humoral immune responses. In B cells, AID expression is regulated at the level of either transcriptional activation on AID gene loci or post-transcriptional suppression of AID mRNA. Furthermore, AID stabilization and targeting are determined by post-translational modifications and interactions with other cellular/nuclear factors. On the other hand, aberrant expression of AID causes B cell leukemias and lymphomas, including Burkitt's lymphoma caused by c-myc/IgH translocation. AID is also ectopically expressed in T cells and non-immune cells, and triggers point mutations in relevant DNA loci, resulting in tumorigenesis. Here, I review the recent literatures on the function of AID, regulation of AID expression, stability and targeting in B cells, and AID-related tumor formation.

Comparison of class switch recombination assays for immunoglobulin synthesis

The second step of immunoglobulin gene alteration consists of somatic hypermutation and class switch recombination. 80th are regulated by activation-induced cytidine deaminase (AID). Methods: Study on possible application of class switch recombination assays for immunoglobulin gene alteration via AID. Cell based assays using AID B lymphocyte and NIH3T3 cell carrying switch substrate; gene transfer using retrovirus system; FACS analysis; PCR and ELISA. Results: DNA sequencing for S region and gamma1CT are the most sensitive and accurate assays. However, gamma1CT assay seemed to be more reliable and applicable. Others are accurate assays but less applicable. Conclusion: gamma1CT determination is the best class switch recombination assay for immunoglobulin gene alteration via AID.