Bioinformatics and expression analysis of the Xeroderma Pigmentosum complementation group C (XPC) of Trypanosoma evansi in Trypanosoma cruzi cells / Análises de bioinformática e da expressão do gene Xeroderma Pigmentosum complementation group C (XPC) de Trypanosoma evansi em células de Trypanosoma cruzi

Abstract Nucleotide excision repair (NER) acts repairing damages in DNA, such as lesions caused by cisplatin. Xeroderma Pigmentosum complementation group C (XPC) protein is involved in recognition of global genome DNA damages during NER (GG-NER) and it has been studied in different organisms due to its importance in other cellular processes. In this work, we studied NER proteins in Trypanosoma cruzi and Trypanosoma evansi, parasites of humans and animals respectively. We performed three-dimensional models of XPC proteins from T. cruzi and T. evansi and observed few structural differences between these proteins. In our tests, insertion of XPC gene from T. evansi (TevXPC) in T. cruzi resulted in slower cell growth under normal conditions. After cisplatin treatment, T. cruzi overexpressing its own XPC gene (TcXPC) was able to recover cell division rates faster than T. cruzi expressing TevXPC gene. Based on these tests, it is suggested that TevXPC (being an exogenous protein in T. cruzi) interferes negatively in cellular processes where TcXPC (the endogenous protein) is involved. This probably occurred due interaction of TevXPC with some endogenous molecules or proteins from T.cruzi but incapacity of interaction with others. This reinforces the importance of correctly XPC functioning within the cell.

Resumo O reparo por excisão de nucleotídeos (NER) atua reparando danos no DNA, como lesões causadas por cisplatina. A proteína Xeroderma Pigmentosum complementation group C (XPC) está envolvida no reconhecimento de danos pela via de reparação global do genoma pelo NER (GG-NER) e tem sido estudada em diferentes organismos devido à sua importância em outros processos celulares. Neste trabalho, estudamos proteínas do NER em Trypanosoma cruzi e Trypanosoma evansi, parasitos de humanos e animais, respectivamente. Modelos tridimensionais das proteínas XPC de T. cruzi e T. evansi foram feitos e observou-se poucas diferenças estruturais entre estas proteínas. Durante testes, a inserção do gene XPC de T. evansi (TevXPC) em T. cruzi resultou em crescimento celular mais lento em condições normais. Após o tratamento com cisplatina, T. cruzi superexpressando seu próprio gene XPC (TcXPC) foi capaz de recuperar as taxas de divisão celular mais rapidamente do que T. cruzi expressando o gene TevXPC. Com base nesses testes, sugere-se que TevXPC (sendo uma proteína exógena em T. cruzi) interfere negativamente nos processos celulares em que TcXPC (a proteína endógena) está envolvida. Isso provavelmente ocorreu pois TevXPC é capaz de interagir com algumas moléculas ou proteínas endógenas de T.cruzi, mas é incapaz de interagir com outras. Isso reforça a importância do correto funcionamento de XPC dentro da célula.

Bioinformatics and expression analysis of the Xeroderma Pigmentosum complementation group C (XPC) of Trypanosoma evansi in Trypanosoma cruzi cells / Análises de bioinformática e da expressão do gene Xeroderma Pigmentosum complementation group C (XPC) de Trypanosoma evansi em células de Trypanosoma cruzi

Nucleotide excision repair (NER) acts repairing damages in DNA, such as lesions caused by cisplatin. Xeroderma Pigmentosum complementation group C (XPC) protein is involved in recognition of global genome DNA damages during NER (GG-NER) and it has been studied in different organisms due to its importance in other cellular processes. In this work, we studied NER proteins in Trypanosoma cruzi and Trypanosoma evansi, parasites of humans and animals respectively. We performed three-dimensional models of XPC proteins from T. cruzi and T. evansi and observed few structural differences between these proteins. In our tests, insertion of XPC gene from T. evansi (TevXPC) in T. cruzi resulted in slower cell growth under normal conditions. After cisplatin treatment, T. cruzi overexpressing its own XPC gene (TcXPC) was able to recover cell division rates faster than T. cruzi expressing TevXPC gene. Based on these tests, it is suggested that TevXPC (being an exogenous protein in T. cruzi) interferes negatively in cellular processes where TcXPC (the endogenous protein) is involved. This probably occurred due interaction of TevXPC with some endogenous molecules or proteins from T. cruzi but incapacity of interaction with others. This reinforces the importance of correctly XPC functioning within the cell.

O reparo por excisão de nucleotídeos (NER) atua reparando danos no DNA, como lesões causadas por cisplatina. A proteína Xeroderma Pigmentosum complementation group C (XPC) está envolvida no reconhecimento de danos pela via de reparação global do genoma pelo NER (GG-NER) e tem sido estudada em diferentes organismos devido à sua importância em outros processos celulares. Neste trabalho, estudamos proteínas do NER em Trypanosoma cruzi e Trypanosoma evansi, parasitos de humanos e animais, respectivamente. Modelos tridimensionais das proteínas XPC de T. cruzi e T. evansi foram feitos e observou-se poucas diferenças estruturais entre estas proteínas. Durante testes, a inserção do gene XPC de T. evansi (TevXPC) em T. cruzi resultou em crescimento celular mais lento em condições normais. Após o tratamento com cisplatina, T. cruzi superexpressando seu próprio gene XPC (TcXPC) foi capaz de recuperar as taxas de divisão celular mais rapidamente do que T. cruzi expressando o gene TevXPC. Com base nesses testes, sugere-se que TevXPC (sendo uma proteína exógena em T. cruzi) interfere negativamente nos processos celulares em que TcXPC (a proteína endógena) está envolvida. Isso provavelmente ocorreu pois TevXPC é capaz de interagir com algumas moléculas ou proteínas endógenas de T. cruzi, mas é incapaz de interagir com outras. Isso reforça a importância do correto funcionamento de XPC dentro da célula.

Bioinformatics and expression analysis of the Xeroderma Pigmentosum complementation group C (XPC) of Trypanosoma evansi in Trypanosoma cruzi cells

Abstract Nucleotide excision repair (NER) acts repairing damages in DNA, such as lesions caused by cisplatin. Xeroderma Pigmentosum complementation group C (XPC) protein is involved in recognition of global genome DNA damages during NER (GG-NER) and it has been studied in different organisms due to its importance in other cellular processes. In this work, we studied NER proteins in Trypanosoma cruzi and Trypanosoma evansi, parasites of humans and animals respectively. We performed three-dimensional models of XPC proteins from T. cruzi and T. evansi and observed few structural differences between these proteins. In our tests, insertion of XPC gene from T. evansi (TevXPC) in T. cruzi resulted in slower cell growth under normal conditions. After cisplatin treatment, T. cruzi overexpressing its own XPC gene (TcXPC) was able to recover cell division rates faster than T. cruzi expressing TevXPC gene. Based on these tests, it is suggested that TevXPC (being an exogenous protein in T. cruzi) interferes negatively in cellular processes where TcXPC (the endogenous protein) is involved. This probably occurred due interaction of TevXPC with some endogenous molecules or proteins from T.cruzi but incapacity of interaction with others. This reinforces the importance of correctly XPC functioning within the cell.

Resumo O reparo por excisão de nucleotídeos (NER) atua reparando danos no DNA, como lesões causadas por cisplatina. A proteína Xeroderma Pigmentosum complementation group C (XPC) está envolvida no reconhecimento de danos pela via de reparação global do genoma pelo NER (GG-NER) e tem sido estudada em diferentes organismos devido à sua importância em outros processos celulares. Neste trabalho, estudamos proteínas do NER em Trypanosoma cruzi e Trypanosoma evansi, parasitos de humanos e animais, respectivamente. Modelos tridimensionais das proteínas XPC de T. cruzi e T. evansi foram feitos e observou-se poucas diferenças estruturais entre estas proteínas. Durante testes, a inserção do gene XPC de T. evansi (TevXPC) em T. cruzi resultou em crescimento celular mais lento em condições normais. Após o tratamento com cisplatina, T. cruzi superexpressando seu próprio gene XPC (TcXPC) foi capaz de recuperar as taxas de divisão celular mais rapidamente do que T. cruzi expressando o gene TevXPC. Com base nesses testes, sugere-se que TevXPC (sendo uma proteína exógena em T. cruzi) interfere negativamente nos processos celulares em que TcXPC (a proteína endógena) está envolvida. Isso provavelmente ocorreu pois TevXPC é capaz de interagir com algumas moléculas ou proteínas endógenas de T.cruzi, mas é incapaz de interagir com outras. Isso reforça a importância do correto funcionamento de XPC dentro da célula.

Clinical characteristics of 16 patients with nucleotide excision repair disorders and literature review / 中华实用儿科临床杂志

Objective:To summarize the clinical manifestations and gene mutation features of patients with nucleotide excision repair (NER) disorders.Methods:A retrospective analysis was made on clinical data of patients with NER disorders who were admitted to the Chinese People′s Liberation Army General Hospital from October 2008 to February 2022 and diagnosed in the Outpatient Department of Beijing Children′s Hospital, Capital Medical University from October 2015 to February 2022.Literature on previously reported Chinese patients with NER disorders was reviewed.Results:(1)A total of 16 patients with NER disorders were enrolled, including 6 males and 10 females.The onset age was 7.5 (4.0, 12.0) months and the age at diagnosis was 42.0 (21.5, 77.0) months.There were 3 types of NER disorders: Cockayne syndrome (CS) in 13 cases, Xeroderma Pigmentosum (XP) in 2 cases and Cerebro-Oculo-Facio-Skeletal syndrome (COFS) in 1 case.Four disease-causing genes were detected: CSA gene in 11 cases, CSB gene in 3 cases, XPG gene in 1 case, and XPD gene in 1 case.The first symptoms of the 16 patients were photosensitivity and developmental delay, and neurological symptoms were observed in all the 3 NER disorder types.XP and CS patients had skin symptoms.CS patients presented typical facial features, visual and auditory impairment, microcephaly and changes in neuroimaging features.COFS patients showed intrauterine growth retardation.(2)Results of literature review: a total of 96 Chinese patients reported were retrieved, involving 6 disease types, including CS in 45 cases, XP in 44 cases, trichothiodystrophy in 4 cases, COFS in 1 case, XP-CS in 1 case, and ultraviolet sensitive syndrome in 1 case.Nine mutated genes were identified: CSA in 33 cases, XPA in 15 cases, CSB in 13 cases, XPV in 10 cases, XPC in 9 cases, XPG in 7 cases, XPD in 7 cases, XPF in 1 case, and MPLKIP in 1 case.The common symptoms were growth failure (62 cases), skin photosensitivity (61 cases), typical facial features (52 cases), mental retardation (49 cases) and microcephaly (48 cases). Among 36 cases had imaging data 33 cases(91.7%)had calcification of basal nucleus or globus pallidus.Three cases had intrauterine growth retardation and microcephaly during pregnancy. Conclusions:Patients with such prenatal manifestations as intrauterine growth retardation and microcephaly or with typical symptoms like skin photosensitivity, typical facial features, growth failure, mental retardation, hypertonia, and calcifications of basal ganglia should be suspected of NER disorders.Early genetic testing is recommended to confirm the diagnosis.

Levels of base excision repair proteins in CD4+ T cells in patients with systemic lupus erythematosus / 中南大学学报(医学版)

OBJECTIVES@#Systemic lupus erythematosus (SLE) is a multi-systemic disease with the unknown pathogenic mechanism. DNA demethylation is involved in SLE pathogenesis. Growth arrest and DNA damage inducible 45 alpha (Gadd45a) takes part in the process of DNA demethylation. Gadd45a is a DNA repair-related protein. This study aims to investigate the expressions of some proteins [including activation-induced cytidine deaminase (AID), thymine DNA glycosylase (TDG), and methyl-CpG-binding domain protein 4 (MBD4)] involving in base excision repair (BER) process in CD4+ T cells in patients with SLE, and to analyze the correlations between the above BER proteins and lupus disease.@*METHODS@#From January 2019 to September 2020, 12 SLE patients and 12 healthy controls were recruited from Second Xiangya Hospital of Central South University. Peripheral blood mononuclear cells (PBMCs) were separated by Ficoll-Hypaque density gradient centrifugation and then CD4+ T cells were isolated via positive selection using Miltenyi beads. We measured the messenger RNA (mRNA) and protein expressions of AID, TDG, and MBD4 by real-time reverse transcription polymerase chain reaction (RT-PCR) and Western blotting, respectively.@*RESULTS@#In contrast to controls, in SLE CD4+ T cells, the mRNA and protein expressions of AID were elevated (P=0.003, P=0.022, respectively); TDG protein expression was increased (P=0.017); and MBD4 protein level was reduced (P<0.001). No visible distinctions was found in the mRNA expressions of either TDG or MBD4 between the 2 groups (both P>0.05). The mRNA and protein expressions of AID and the protein levels of TDG were positively correlated with SLE disease activity index (SLEDAI). And the mRNA and protein expressions of MBD4 were negatively correlated with SLEDAI.@*CONCLUSIONS@#In SLE CD4+ T cells, the increased expressions of AID and TDG and the decreased MBD4 expression may participate in SLE pathogenic mechanism.

Alterations of DNA damage response pathway: Biomarker and therapeutic strategy for cancer immunotherapy

Genomic instability remains an enabling feature of cancer and promotes malignant transformation. Alterations of DNA damage response (DDR) pathways allow genomic instability, generate neoantigens, upregulate the expression of programmed death ligand 1 (PD-L1) and interact with signaling such as cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) signaling. Here, we review the basic knowledge of DDR pathways, mechanisms of genomic instability induced by DDR alterations, impacts of DDR alterations on immune system, and the potential applications of DDR alterations as biomarkers and therapeutic targets in cancer immunotherapy.

DNA alkylation lesion repair: outcomes and implications in cancer chemotherapy / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Alkylated DNA lesions, induced by both exogenous chemical agents and endogenous metabolites, represent a major form of DNA damage in cells. The repair of alkylation damage is critical in all cells because such damage is cytotoxic and potentially mutagenic. Alkylation chemotherapy is a major therapeutic modality for many tumors, underscoring the importance of the repair pathways in cancer cells. Several different pathways exist for alkylation repair, including base excision and nucleotide excision repair, direct reversal by methyl-guanine methyltransferase (MGMT), and dealkylation by the AlkB homolog (ALKBH) protein family. However, maintaining a proper balance between these pathways is crucial for the favorable response of an organism to alkylating agents. Here, we summarize the progress in the field of DNA alkylation lesion repair and describe the implications for cancer chemotherapy.

The role of nucleotide excision repair on 2,6- and 3,5-dimethylaniline-induced genotoxicity

Aim: To examine the possible role of nucleotide excision repair (NER) in affecting the ultimate mutagenic potency of 2,6- and 3,5-dimethylaniline (DMA) and their metabolites.Methodology: Two cell lines, nucleotide excision repair (NER)-proficient AA8 and deficient UV5 cells were treated with 50, 100, 250, 500 and 1000 μM of 2,6- and 3,5-DMA for 48 hr or their N-hydroxyl and aminophenol metabolites for 1 hr. Cell survival was determined by trypan blue exclusion assay, and 8-azaadenine-resistant mutants at adenine phosphoribosyltransferase (aprt) gene locus were evaluated.Results: A dose-dependent increase in cytotoxicity and mutant fraction was observed in AA8 and UV5 cells, treated with 2,6- and 3,5-DMA and their metabolites, but showed considerable variation in potency; N-hydroxyl and aminophenol metabolites of 2,6- and 3,5-DMA in serum-free α-minimal essential medium (MEM) having the highest potency, and 2,6- and 3,5-DMA in regular MEM at least. Repair-deficient UV5 cells were more sensitive to cytotoxic and mutagenic action than repair-proficient AA8 cells. Interpretation: These findings suggest that 2,6- and 3,5-DMA-induced DNA damage response may trigger cytotoxicity and mutagenicity when not completely repaired

Is excision repair cross-complementation Group1 expression a biological marker in nasopharynx carcinoma?

Objective: To determine the prognostic value of excision repairs cross-complementation group1 (ERCC1) gene in cases with nasopharyngeal carcinoma (NPC) treated with platinum-containing chemotherapy (PCT). Subjects and Methods: The present study was included 33 cases in local advanced stage with NPC. ERCC1 expression was evaluated by using immunohistochemical staining in biopsy specimens. We evaluated the relationship between the degree of ERCC1 expression and clinicopathological features, response to therapy, survival rates in cases with NPC, retrospectively. Results: ERCC1 expression was not observed in 5 (15.15%) of all cases. Thirteen (39.9%) cases weakly positive (+1, +2) and 15 (45.5%) cases of all them were rather strongly positive (+3). There was no statistically significant difference between the degree of ERCC1 expression and clinicopathological features, response to treatment, survival rates (P > 0.05) in cases with NPC. Conclusions: ERCC1 expression has no predictive value for survival in cases locally advanced stage with NPC. Evaluation of ERCC1 expression is not appropriate with a biomarker to detect cases who can benefit from PCT in NPC

Mechanisms of miR-503 inhibiting radio-resistance of esophageal squamous cell carcinoma cells by targeting ERCC1 / 中国肿瘤生物治疗杂志

@# Objective: To investigate the mechanism of miR-503 modulates radio-resistance of esophageal squamous cell carcinoma (ESCC) by targeting excision-repair cross-complementing 1 (ERCC1). Methods: The expression level of miR-503 in radio-resistant ESCC tumor tissues and KYSE140 and KYSE140R cells was detected by qPCR. The miR-503 mimic, miR-503 inhibitor or si-ERCC1 was transfected into KYSE140 and KYSE140R cells.After radiation treatment, the colony formation assay and CCK-8 assay were used to detect the proliferation of KYSE140R cells. Flow cytometry was used to detect apoptosis of KYSE140R cells. WB was used to detect changes in protein expression of ERCC1. Dual luciferase reporter gene assay was used to validate the targeting relationship between miR-503 and ERCC1. Results: The expression level of miR-503 was down-regulated in radio-resistant tissues and ESCC cell lines (all P<0.01). Over-expression of miR-503 significantly inhibited cell proliferation and promoted apoptosis of KYSE140R cells (all P<0.01). Dual-luciferase reporter assay validated that ERCC1 was a target gene of miR-503, and miR-503 negatively regulated the expression of ERCC1. Over-expression of miR-503 significantly down-regulated the expression of ERCC1 in KYSE140 and KYSE140R cells (both P<0.01), inhibited cell proliferation (both P<0.01), but significantly increased apoptosis rate (all P<0.01); knockdown of ERCC1 exhibited a similar effect, while knockdown of both ERCC1 and miR-503 reversed the above effects. Conclusion: Over-expression of miR-503 up-regulated the radio-sensitivity of KYSE140R cells by targeting ERCC1.

Radiotherapy modulates expression of EGFR, ERCC1 and p53 in cervical cancer

Cervical cancer is a public health problem and the molecular mechanisms underlying radioresistance are still poorly understood. Here, we evaluated the modulation of key molecules involved in cell proliferation, cell cycle and DNA repair in cervical cancer cell lines (CASKI and C33A) and in malignant tissues biopsied from 10 patients before and after radiotherapy. The expression patterns of epidermal growth factor receptor (EGFR), excision repair cross-complementation group 1 (ERCC1) and p53 were evaluated in cancer cell lines by quantitative PCR and western blotting, and in human malignant tissues by immunohistochemistry. The mutation status of TP53 gene was evaluated by direct sequencing. Among cell lines, absent or weak modulations of EGFR, ERCC1 and p53 were observed after exposure to 1.8 Gy. Conversely, increased expressions of p53 (5/10 patients; P=0.0239), ERCC1 (5/10 patients; P=0.0294) and EGFR (4/10 patients; P=0.1773) were observed in malignant tissues after radiotherapy with the same radiation dose. TP53 mutations were found only in one patient. Here we show that a single dose of radiotherapy induced EGFR, ERCC1 and p53 expression in malignant tissues from cervical cancer patients but not in cancer cell lines, highlighting the gap between in vitro and in vivo experimental models. Studies on larger patient cohorts are needed to allow an interpretation that an upregulation of p53, EGFR and ERCC1 may be part of a radioresistance mechanism.

Protective effect of Wuzi Yanzong Prescription on testicular DNA damage in natural ageing rats based on P53/P21 and BER signal pathway / 中草药

Objective: To study the protective effect of Wuzi Yanzong Prescription (WYP) on DNA damage in testis of natural ageing rats based on P53/P21 signaling pathway and base excision repair (BER). Methods: SPF grade 16-month-old male SD rats were randomly divided into three groups with eight rats in each group: ageing model group, low and high dose of WYP groups (1 and 4 g/kg). In addition, 2-month-old SD male rats were used as adult control group. The ageing model group and the adult control group were fed with normal diet for four months. Rats in the WYP groups were given the medicated feed for four months. After fasting for 12 h, the rats were sacrificed. Then, the testes were immediately removed from rats. The expression and localization of DNA damage-related protein γH2AX and BER-related proteins OGG1, APE1, and XRCC1 were detected by immunofluorescence, and the content of 8-OHdG in testis was detected by ELISA. Also, the protein expression levels of p-P53 and P21 were detected by Western blotting. Results: Compared with the ageing model group, immunofluorescence results showed WYP significantly decreased the expression levels of DNA damage-related protein γH2AX and BER-related proteins OGG1, APE1, and XRCC1 in testis of natural ageing rats. ELISA results showed that WYP significantly downregulated 8-OHdG levels, compared with the ageing model group. Moreover, Western blotting results showed that WYP significantly decreased the protein expression levels of p-P53 and P21 of the testis when compared with the ageing model group. Conclusion: WYP reduced the DNA damage of testes in ageing related rats via P53/P21 and BER pathways.

Association of Base Excision Repair Gene Polymorphisms with the Response to Chemotherapy in Advanced Non-Small Cell Lung Cancer / 中华医学杂志(英文版)

Background@#Base excision repair (BER) plays an important role in the maintenance of genome integrity and anticancer drug resistance. This study aimed to explore the role of BER gene polymorphisms in response to chemotherapy for advanced non-small cell lung cancer (NSCLC) patients treated with platinum-based chemotherapy.@*Methods@#During the period from November 2009 to January 2016, a total of 152 patients diagnosed with NSCLC Stage IIIB and IV in the First Hospital of Jilin University were admitted into this study. The XRCC1 G28152A, MUTYH G972C, HOGG1 C1245G, and PARP1 T2444C polymorphisms of all the patients were detected by mass spectrometry. The logistic regression was used for statictical analysis. All tests were bilateral test, and a P < 0.05 was considered statistically significant.@*Results@#The logistic regression model showed that the response rate of chemotherapy of the PARP1 T2444C polymorphisms, CC genotype (odds ratio [OR]: 5.216, 95% confidence interval [CI]: 1.568-17.352, P = 0.007), TC genotype (OR: 2.692, 95% CI: 1.007-7.198, P = 0.048), as well as the genotype of TC together with CC (OR: 3.178, 95% CI: 1.229-8.219, P = 0.017) were significantly higher than those of TT wild type. There was no relationship between the MUTYH G972C, XRCC1 G28152A, and HOGG1 C1245G gene polymorphisms and chemosensitivity.@*Conclusions@#The PARP1 2444 mutation allele C might be associated with the decreased sensitivity to platinum-based chemotherapy in advanced NSCLC. These findings may be helpful in designing individualized cancer treatment.

Parallel Mining of Gene Expression Differences of Nucleotide Excision Repair Gene XPA in Human Skin Microarrays based on GEO Database / 昆明医科大学学报

Objective To make a parallel mining the data of expression differences of a crucial gene XPA involved in nucleotide excision repair pathway of human skin microarrays by bioinformatics from the system level.Methods Using the ScanGEO, the data of microarrays which included the significant differences expression level of XPA were screened and analyzed from 59 human skin samples in the GEO database. Results There were 7 samples with the down-regulated expression of XPA: cutaneous malignant melanoma, epidermal injury model, DNA damage and UV radiation, foreskin fibroblast response to Toxoplasma gondii RH type 1 (ROP5) mutant infection, interleukin-20 subfamily cytokines effect on epidermal keratinocytes, Egr-1 overexpression effect on skin fibroblasts in vitro: time course, in vitro model for inflammatory dendritic cells.Present expression down. Conclusion Based on the GEO database and ScanGEO, high-throughput shared data can be screened and analyzed efficiently.

Protective effect of Wuzi Yanzong recipe on testicular DNA oxidative damage in natural ageing rats / 中国中药杂志

To study the protective effects of Wuzi Yanzong recipe on DNA oxidative damage of testis germ cells in natural ageing rats based on Nrf2/HO-1 signaling pathway and base excision repair (BER). In the study, 16-month-old SPF grade male SD rats were randomly divided into three groups, namely ageing model group, and low and high-dose Wuzi Yanzong recipe groups (WZ, 1, 4 g·kg⁻¹). In addition, 2-month-old SD rats were used as adult control group (10 rats in each group). The ageing model group and the adult control group were fed with normal diet for 4 months. WZ groups were given medicated feed for 4 months. After fasting for 12 hours, the rats were put to death. Then, the testes were immediately removed. The vitality of superoxide dismutase (SOD) and malondialdehyde (MDA) content in testis were detected by xanthine oxidase method and thiobarbituric acid (TBA) method. The levels of Nrf2 and 8-OHdG were detected by immunofluorescence. The protein expression levels of Nrf2, HO-1, NQO1, APE1, OGG1 and XRCC1 were detected by Western blot. Compared with the ageing model group, WZ significantly increased the SOD vitality and decreased MDA content of testis. In addition, immunofluorescence results showed that WZ significantly attenuated testicular DNA oxidative damage and improved antioxidant capacity. Such changes were accompanied by the down-regulation of DNA oxidative damage response protein 8-OHdG levels and the up-regulation of Nrf2 levels. Moreover, Western blot results showed that WZ significantly increased the protein expression levels of Nrf2, HO-1 and NQO1 of the testis germ cells, when compared with ageing model group. In parallel, the protein expression levels of APE1, OGG1 and XRCC1 were significantly decreased. In conclusion, WZ improves ageing-related DNA oxidative damage via Nrf2/HO-1 and BER pathways.

Base excision repair and targeted therapy strategies / 国际肿瘤学杂志

Base excision repair (BER) is an important pathway for DNA oxidative damage repair,and mutations in this pathway cause gene instability and increase cancer risk.A large number of studies have shown that abnormal expression of key proteins in the BER pathway in a variety of tumors,such as DNA glycosylase,apurinic/apyrimidinic endonuclease 1,DNA polymerase and so on.Single nucleotide polymorphisms of these proteins affect the repair activity of tumor cells,and are expected to be important indicators for the diagnosis,treatment and evaluation of prognosis.

Correlation of TS, ERCC1,β-tubulin-Ⅲ and RRM1 expressions with EGFR mutations in non-small cell lung cancer / 医学研究生学报

Objective Currently , the targeted therapy is the first-choice treatment of advanced non-small cell lung cancer (NSCLC) in with epidermal growth factor receptor (EGFR) mutations, but few studies have been reported on the relationship between immunohistochemical markers and the EGFR mutation.The aim of this study is to analyze the relationship of the EGFR mutation with the ex-pressions of thymidylate synthetase (TS), excision repair cross-com-plementation group 1 ( ERCC1 ) , β-tubulin-III, and ribonucleofide reductase large subunit-l ( RRM1) in NSCLC. Methods We retro-spectively analyzed 336 cases of NSCLC treated in the Department of Medical Oncology , the Affiliated Hospital of Inner Mongolia Medical University, from June 2014 to December 2015 and examined 29 EGFR mutations.We divided the patients into a mutation and a non-mutation group, performed immunohistochemical staining of the TS, ERCC1,β-tubulin-III and RRM1 proteins and compared their expressions in the NSCLC tissue between the two groups . Results EGFR mutations were found in 138 ( 41.07%) of the 336 NSCLC patients but not in the other 198 ( 58.93%) .The expression of TS was significantly lower in the mutation than in the non-mutation group (9.42%vs 39.39%, P<0.05), and so was that of β-tubulin-III (44.2%vs 60.1%, P<0.05).EGFR mutations were correlated with decreased expressions of TS (r=-0.332, P<0.05) andβ-tubulin-III (r=-0.157, P<0.05).Multivariate regression analysis showed that the risk of EGFR mutations was 2.109 times higher in the fe-male patients than in the males (OR=2.109, 95%CI:1.268-3.509), 24.265 times higher in the adenocarcinoma than in the adeno-squamous carcinoma patients (OR=24.265, 95%CI:3.508-167.845), 15.2 times higher in the squamous carcinoma than in the ade-nocarcinoma patients (OR=15.200, 95%CI:4.480-51.569), 2.364 times higher in the lung biopsy specimens than in the surgically treated patients (OR=2.364, 95%CI:1.266-4.413), and 6.171 times higher in the patients with lowly expressed than in those with highly expressed TS (OR=6.171, 95%CI: 3.145-12.109). Conclusion The decreased expressions of TS and β-tubulin-Ⅲ in NSCLC indicate the mutation of the EGFR gene.

Clinical significance of the expression levels of ERCC1, BRCA1 and TS in advanced colorectal cancer / 中国医师进修杂志

Objective To explore the relationship between the expression levels of excision repair cross complementation group 1(ERCC1), breast cancer susceptibility gene 1(BRCA1), thymidylate synthase (TS) mRNA and clinicopathological features, prognosis in advanced colorectal cancer, and the correlation between the expression levels of ERCC1 and BRCA1. Methods The expression levels of ERCC1, BRCA1 and TS mRNA of postoperative paraffin embedded tissue were tested by real-time quantitative reverse transcription polymerase chain reaction (RT-PCR) in 49 advanced colorectal cancer cases. The results were analyzed by χ2 test of the correlation between the expression levels and clinicopathological characteristics. Patients were followed up by clinic or telephone. The prognosis was analyzed by small sample Kaplan-Meier survival analysis and Log-rank time series analysis, and P0.05). The expression level of BRCA1 mRNA had no significant correlation with the above clinical and pathological features (P>0.05) except distant metastasis (P=0.030) and differentiation degree (P=0.002). The expression level of TS mRNA had no significant correlation with the above clinical and pathological features (P>0.05) except distant metastasis (P=0.003). The expression level of ERCC1 and BRCA1 mRNA obviously correlated (P=0.002). The 1 year overall survival rate was 95.92%(47/49);the 2 year overall survival rate was 83.67%(41/49);and the 3 year overall survival rate was 73.47%(36/49). Overall survival and progression-free survival time in ERCC1 mRNA low expression group (47.8, 41.0 months) was higher than that in ERCC1 mRNA low expression group (27.3, 20.0 months) respectively (P=0.001, P=0.001). Overall survival and progression-free survival time in BRCA1 mRNA low expression group (43.7, 42.7 months) was higher than that in BRCA1 mRNA high expression group (29.3, 25.1 months) respectively (P=0.009, 0.006). Overall survival time in TS mRNA low expression group (39.8 months) was higher than that in BRCA1 mRNA high expression group (25.2 months). Conclusions The expression level of ERCC1 mRNA is not correlated with its clinical and pathological characteristics, but with its biological characteristics. BRCA1 and TS levels are correlated with invasion and metastasis. Low levels of ERCC1 and BRCA1 expression have a better prognostic effect on platinum based first-line chemotherapy for advanced colorectal cancer, and they are correlated. Low level of TS also has longer disease-free survival. Three joint detection could be used as a prognostic factor for colorectal cancer chemotherapy.

Differential expression and prognostic value of excision repair cross-complementing gene-1 in resected gastric adenocarcinoma / 中国综合临床

Objective Excision repair cross-complementing gene-1(ERCC1) are key regulatory enzymes whose expression patterns are associated with overall survival(OS) in several malignancies.Their expression patterns and prognostic value in resected gastric adenocarcinoma(GAC) are not known and need to investigate.Methods A total of 109 patients who underwent resection for GAC in Liu′an People′s Hospital from January 2010 to June 2013 had tissue available for analysis.The primary objective was to assess for the differential expression of ERCC1 using by immunohistochemistry.The secondary objective was to assess for the association between OS and the expression of ERCC1.Results The median follow-up was 21.2 months,and the median OS was 28.8 months.Resected GAC exhibited differential expression of ERCC1(high expression,n=25(23%)).ERCC1 expression was not associated with OS(18.9 months vs.27.7 months,P=0.72).In a subset analysis of patients who received chemotherapy(n=73),high ERCC1 expression was associated with decreased OS(16.7 months vs.53.8 months,P=0.03).After controlling for known adverse pathologic features,high ERCC1 expression persisted as a negative prognostic factor in multivariate Cox regression analysis(HR=2.22,95% CI1.05-4.98,P<0.05).Conversely,in patients who underwent resection only(n=35),high ERCC1 expression demonstrated a trend toward improved OS(40.4 months vs.12.7 months,P=0.10).A positive prognostic influence also was present on multivariate analysis(HR=0.20,95% CI0.05-0.84,P=0.03).Conclusion Resected GAC exhibited differential expression of ERCC1.Among all patients,ERCC1 expression levels were not associated with OS.High ERCC1 tumor expression is associated with decreased OS in the patients who received chemotherapy but is associated with increased OS in those who underwent surgery alone.ERCC1 expression have prognostic value in resected gastric cancer,and further investigation is needed.

Expression of ERCC-1 protein and its clinical implication in locally advanced cervical cancer / 中华放射肿瘤学杂志

Objective To examine the protein expression of the nucleotide excision repair gene (ERCC-1) in patients with locally advanced cervical cancer and its relationship with the efficacy of radiotherapy and chemotherapy.Methods The expression of ERCC-1 protein in 88 patients with locally advanced cervical cancer treated in our hospital between 2007-2011 was measured using immunohistochemistry (IHC).The patients were divided into high-expression group (n=48) and low-expression group (n=40) based on the fluorescence intensity on the IHC staining.All patients received cisplatin (40 mg/m2 per week) during radiotherapy.The relationship between ERCC-1 protein expression and the clinicopathological factors of cervical cancer was analyzed using the chi-square test.Survival was calculated using the Kaplan-Meier method and compared by the log-rank test.Multivariate prognostic analysis was performed using the Cox model.Results The overall response rate (CR+PR) was 81%(39/48) in the high-ERCC-1 expression group and 85%(34/40) in the low-ERCC-1 expression group (P=0.641).ERCC-1 protein expression was associated with recurrence and metastasis (P=0.043,0.043).The 5-year survival rate was significantly higher in the low-ERCC-1 expression group than in the high-ERCC-1 expression group (65% vs.42%, P=0.029).Conclusions Patients with high ERCC-1 protein expression are more likely to have local recurrence and distant metastasis than those with low ERCC-1 protein expression.ERCC-1 protein expression may be a clinically significant biomarker for predicting the prognosis of cervical cancer patients.