Evaluation of Meibomian gland dysfunction using meibography in patients with xeroderma pigmentosum

ABSTRACT Purpose: To assess Meibomian gland dysfunction using meibography in patients with xeroderma pigmentosum and correlate with ocular surface changes. Methods: This cross-sectional study evaluated patients with xeroderma pigmentosum. All patients underwent a comprehensive and standardized interview. The best-corrected visual acuity of each eye was determined. Detailed ophthalmic examination was conducted, including biomicroscopy examination of the ocular surface, Schirmer test type I, and meibography, and fundus examination was also performed when possible. Meibomian gland dysfunction was assessed by non-contact meibography using Oculus Keratograph® 5M (OCULUS Inc., Arlington, WA, USA). Saliva samples were collected using the Oragene DNA Self-collection kit (DNA Genotek Inc., Ottawa, Canada), and DNA was extracted as recommended by the manufacturer. Factors associated with abnormal meiboscores were assessed using generalized estimating equation models. Results: A total of 42 participants were enrolled, and 27 patients underwent meibography. The meiboscore was abnormal in the upper eyelid in 8 (29.6%) patients and in the lower eyelid in 17 (62.9%). The likelihood of having abnormal meiboscores in the lower eyelid was 16.3 times greater than that in the upper eyelid. In the final multivariate model, age (p=0.001), mutation profile (p=0.006), and presence of ocular surface malignant tumor (OSMT) (p=0.014) remained significant for abnormal meiboscores. For a 1-year increase in age, the likelihood of abnormal meiboscores increased by 12%. Eyes with OSMT were 58.8 times more likely to have abnormal meiboscores than eyes without ocular surface malignant tumor. Conclusion: In the final model, age, xeroderma pigmentosum profile, previous cancer, and clinical alterations on the eyelid correlated with a meiboscore of ≥2. Meibomian gland dysfunction was common in patients with xeroderma pigmentosum, mainly in the lower eyelid. The severity of Meibomian gland dysfunction increases with age and is associated with severe eyelid changes.

Progress of PARP inhibitors in targeted therapy of small cell lung cancer / 国际肿瘤学杂志

Small cell lung cancer (SCLC) is a rapidly developing malignant tumor, which is highly heterogeneous and prone to drug resistance, and the prognosis is usually poor. Poly ADP-ribose polymerase (PARP) inhibitors target the DNA damage response pathway, preventing DNA repair, thereby exerting anti-tumor effects. Currently, PARP inhibitors are used as monotherapy or in combination with DNA-damaging agents or immune checkpoint inhibitors in the treatment of SCLC. Although the current research results are limited, it can be seen that PARP inhibitors may be a breakthrough in the targeted therapy of SCLC.

Colorectal cancer: histopathological profile and prevalence of dna repair system deficiency in patients submitted to surgical treatment in a university hospital / Câncer colorretal: perfil histopatológico e prevalência da deficiência do sistema de reparação do dna em pacientes submetidos a tratamento cirúrgico em um hospital universitário

ABSTRACT BACKGROUND: Part of colorectal cancer cases occurs due to modifications in the DNA mismatch repair system, which are responsible for microsatellite instability. This alteration results in an unconventional phenotypic pattern of colorectal cancer. AIMS: To describe the epidemiological, histopathological and molecular profiles of patients with colorectal cancer who underwent surgical treatment in a reference hospital. METHODS: This is a cross-sectional, retrospective study with a quantitative approach, that included a review of patients' medical records who underwent oncological surgery for colorectal cancer. RESULTS: A total of 122 colorectal cancer cases were identified, with microsatellite instability detected in 8.2% of the sample. The gender distribution was similar, with 52.46% males, and the weighted average age was 63 years (standard deviation±11.65). However, in the microsatellite instability group, the predominant age was below 60 years. Regarding the histological type, adenocarcinoma not otherwise specified accounted for 80.33% of the cases, being the most prevalent in both groups, with the mucinous type being more frequent among the instability cases. The pT3 pathological staging (46.72%) was the most predominant. The topography was more prevalent on the left (60.66%), but there was a significant difference when compared to the group with microsatellite instability, in which 80% of the neoplasms were located on the right (p=0.006). CONCLUSIONS: Differences in age and neoplastic topography found in microsatellite instability samples highlight the distinctive presentation pattern of the disease. Recognizing these characteristics is essential for developing prevention strategies, in addition to early and accurate diagnosis of colorectal cancer.

RESUMO RACIONAL: Parte dos casos de câncer colorretal ocorre devido a alterações nas enzimas de reparo do DNA, responsáveis pela instabilidade de microssatélites. Esta alteração resulta em um padrão fenotípico não convencional de câncer colorretal. OBJETIVOS: Descrever os aspectos epidemiológicos, histopatológicos e moleculares dos pacientes com câncer colorretal submetidos a tratamento cirúrgico em hospital de referência. MÉTODOS: Trata-se de um estudo transversal, retrospectivo com abordagem quantitativa, com revisão de prontuários médicos de pacientes submetidos a cirurgia oncológica por câncer colorretal. RESULTADOS: Foram registrados 122 casos de câncer colorretal, com instabilidade de microssatélites detectada em 8,2% da amostra. A distribuição por sexo foi semelhante, sendo 52,46% do sexo masculino, e média ponderada de idade de 63 anos (±11,65), contudo no grupo com instabilidade, a faixa etária predominante foi abaixo de 60 anos. Em relação ao tipo histológico, o adenocarcinoma sem outra especificação representou 80,33% dos casos, sendo o mais prevalente em ambos os grupos, mas com maior frequência do tipo mucinoso em caso de instabilidade. O estadiamento patológico pT3 (46,72%) foi predominante. A topografia da neoplasia foi mais prevalente à esquerda (60,66%), mas houve diferença significativa em relação ao grupo com instabilidade de microssatélites, no qual 80% das neoplasias localizavam-se à direita (p=0,006019). CONCLUSÕES: As diferenças de idade e topografia neoplásica encontradas nas amostras com instabilidade de microssatélites destacam o padrão não habitual de apresentação da doença. O conhecimento, portanto, dessas distinções é necessário para o desenvolvimento de estratégias de prevenção, além de diagnóstico precoce e preciso do câncer colorretal.

Functional polymorphisms of DNA repair genes in Latin America reinforces the heterogeneity of Myelodysplastic Syndrome

Abstract Nucleotide excision repair pathway (NER) is an essential mechanism for single-strand breaks (SSB) repair while xeroderma pigmentosum family (XPA to XPG) is the most important system to NER. Myelodysplastic syndrome (MDS) is a heterogeneous hematological cancer characterized by cytopenias and risk of acute myeloid leukemia (AML) transformation. MDS pathogenesis has been associated with problems of DNA repair system. This report aimed to evaluate NER polymorphisms (XPA rs1800975, XPC rs2228000, XPD rs1799793 and XPF rs1800067) in 269 MDS patients of different populations in Latin America (173 Brazilian and 96 Argentinean). Genotypes were identified in DNA samples by RT-qPCR using TaqMan SNP Genotyping Assay. Regarding rs1799793 polymorphism of XPD for Brazilian population, the heterozygous genotype AG presented a high odds ratio (OR) to have a normal karyotype (p= 0.012, OR=3.000) and the mutant homozygous genotype AA was associated to a high OR of AML transformation (p= 0.034, OR=7.4). In Argentine population, the homozygous mutant AA genotype of rs1800975 polymorphism of XPA was associated with an increased odd to have hemoglobin levels below 8g/dL (p= 0.013, OR=10.000) while for the rs1799793 polymorphism of XPD, the heterozygous AG genotype decreased OR to be classified as good (p< 0.001, OR=9.05 × 10−10), and intermediate (p< 0.001, OR=3.08 × 10−10), according to Revised-International Prognostic Scoring System. Regarding the rs1800067 polymorphisms of XPF, the homozygous mutant AA genotype showed a decreased OR to be classified as good (p< 0.001, OR=4.03 × 10−13) and intermediate (p< 0.001, OR=2.54 × 10−13). Our report reinforces the heterogeneity of MDS and demonstrates the importance of ethnic differences and regional influences in pathogenesis and prognosis of MDS.

Xeroderma pigmentosum: case report / Xeroderma pigmentoso: relato de caso

Abstract Objective: The aim of this study was to describe the disease and treatment and to alert health professionals for the identification of signs and symptoms and the need for an early diagnosis in patients with xeroderma pigmentosum (XP). Case description: An 8-year-old male patient was referred to the Joana de Gusmão Hospital (HIJG) in 2021 for evaluation and specialized care. Previously, the child was followed in his place of origin by oncologic and palliative care, where he was submitted to surgeries and chemotherapy. He was admitted to the HIJG using vismodegib, acitrein, tramadol, and solar protective measures. On physical examination, there were tumors and disseminated macular verrucous and ulcerated lesions. The imaging examination showed solid and expansive lesions on the face, and atelectasis and fibroscarring changes in the lung. The histopathological report proved the existence of melanocanthoma, carcinoma, and pyogenic granuloma. After the evaluation of the case, no surgery, chemotherapy, or radiotherapy was performed. It was decided to maintain the palliative treatment and to continue the use of tramadol for pain, and vismodegib and acitretin were used to control carcinomas and prophylactic measures. Comments: The XP is a rare disease of autosomal recessive inheritance whose mechanism comes from failure in the DNA repair by exposure to ultraviolet rays, resulting in lesions on the skin and mucous membranes. They start as sunburns and can progress to melanosis, areas with altered pigmentation, premature aging, poikiloderma, and areas of high risk for neoplasms.

RESUMO Objetivo: Descrever a patologia e o tratamento realizado e alertar profissionais de saúde sobre os sinais e sintomas e sobre a necessidade de diagnóstico precoce em pacientes com xeroderma pigmentoso (XP). Descrição do caso: Paciente do sexo masculino, oito anos, foi encaminhado ao Hospital Joana de Gusmão (HIJG) em 2021, com dianóstico de XP, para avaliação e atendimento especializado. Anteriomente, encontrava-se em serviço de oncologia e de cuidados paliativos em sua cidade de origem, mas já realizara cirurgias e quimioterapias previamente. Foi internado no HIJG em uso de vismodegibe, acitretina, tramadol e medidas de proteção solar. Ao exame físico, apresentou lesões maculares, verrucosas, ulceradas e tumores pelo corpo. Os exames de imagem revelaram lesões sólidas e expansivas na face e atelectasias e alterações fibrocicroscópicas no pulmão. O laudo histopatológico comprovou a existência de melanocantoma, carcinoma e granuloma piogênico. Após a avaliação do caso, optou-se por não realizar cirurgias, quimioterapia nem radioterapia. Decidiu-se manter o tratamento paliativo, continuando o uso de tramadol para dor, vismodegibe e acitretina para o controle de carcinomas e profilaxia à exposição ao sol. Comentários: O XP é uma doença rara de herança autossômica recessiva, cujo mecanismo provém de falha no reparo do DNA pela exposição à luz ultravioleta, resultando em lesões de pele e mucosas. Inicia-se como queimaduras solares e pode avançar para melanoses, áreas com pigmentação alterada, envelhecimento precoce, poiquilodermia e áreas de alto risco neoplásico.

Effects of low-dose radiation on oxidative stress and damage repair in HBE cells / 中国辐射卫生

@#<b>Objective</b> To investigate the effects of lowdose ionizing radiation (LDIR) on oxidative stress and damage repair in human bronchial epithelial (HBE) cells. <b>Methods</b> HBE cells were divided into 0, 50, 100, and 200 mGy groups, and cultured for 24 and 48 h after X-ray irradiation, respectively. The cell viability, levels of glutathione (GSH), malondialdehyde (MDA), and 8-hydroxy-2’-deoxyguanosine (8-OHdG), and transcriptional levels of DNA damage repair genes <i>PPP2R2D</i> and <i>TP53</i> were measured. <b>Results</b> At 24 h after irradiation, there was no significant difference in the cell viability between the dose groups and the control group (<i>P</i> > 0.05); all dose groups had significantly increased MDA level, dose-dependently decreased GSH level, dose-dependently increased 8-OHdG level, and significantly increased mRNA level of <i>PPP2R2D</i> gene (all <i>P</i> < 0.05); the mRNA expression level of <i>TP53</i> gene was significantly increased in the 50 mGy group (<i>P</i> < 0.05). At 48 h after irradiation, there were the highest cell viability, significantly decreased MDA and 8-OHdG levels, and significantly increased mRNA expression levels of <i>PPP2R2D</i> and <i>TP53</i> genes in the 50 mGy group compared with the control group (all <i>P</i> < 0.05); the GSH level in the 100 mGy group was significantly increased (<i>P</i> < 0.05). <b>Conclusion</b> LDIR, especially radiation at 50 mGy, can affect the oxidative-antioxidant level in HBE cells and the transcript-level differential expression of DNA damage repair genes.

Study of the effect of PU-H71 on increasing radiosensitivity of cervical cancer cells / 中华放射肿瘤学杂志

Objective:To investigate the effect of heat shock protein 90 (Hsp90) inhibitor PU-H71 combined with X-ray on radioresistant human cervical cancer cells.Methods:The expression levels of Hsp90 gene between cervical cancer tissues and adjacent tissues were analyzed by bioinformatics. Radioresistant cervical cancer cell lines HeLa RR and SiHa RR were obtained by fractional irradiations (2 Gy per fraction, 30 fractions). The cell lines were divided into the control group (treated with dimethyl sulfoxide), irradiation alone group, PU-H71 group (treated with 0.5 μmol/L PU-H71), and PU-H71+irradiation group (irradiation at 24 h after treatment with 0.5 μmol/L PU-H71). Cell survival was detected by clonal formation assay. Immunofluorescence assay was used to detect γH2AX foci at 1, 6, and 24 h after cell treatment. The expression level of Rad51 protein at 1, 2, 6, 12, and 24 h after cell treatment was detected using Western blot. The expression level of phosphorylated DNA-dependent protein kinase catalytic subunit (p-DNA-PKcs) was measured at 2 h after cell treatment. Cell apoptosis at 48 h after cell treatment was assessed by flow cytometry. Results:PU-H71 enhanced the sensitivity of radioresistant cervical cancer cells to X-ray. Compared with the irradiation alone group, the radiation sensitization ratios (SER) of HeLa RR and SiHa RR cells at 10% survival were 1.36 and 1.27, and the apoptosis rates were increased by approximately 72.1% and 63.1% in the PU-H71+irradiation group, respectively. PU-H71 delayed the duration of γH2AX foci induced by X-ray, inhibited the phosphorylation of DNA-dependent protein kinase catalytic subunit (DNA-PKcs), thus preventing non-homologous end joining (NHEJ) repair and delaying homologous recombination repair.Conclusion:PU-H71 increases the radiosensitivity of radioresistant cervical cancer cells by inhibiting the repair pathway of DNA double-strand break, which is expected to be a radiosensitizer to enhance the efficacy of radiotherapy for cervical cancer.

A review on mechanisms of resistance to PARP inhibitors

Standard therapy for advanced ovarian cancer (OC) consists of radical debulking cytoreductive surgery followed by adjuvant chemotherapy. An important risk factor for OC is genetic predisposition, with BRCA1 or BRCA2 mutations accounting for the majority of hereditary OC. Mutation in BRCA ultimately causes accumulation of genetic alterations because of the failure of cells to arrest and repair DNA damage or to undergo apoptosis, resulting in tumorigenesis. Poly (ADP?ribose) polymerase (PARP) inhibitors have emerged as a promising approach for managing BRCA?associated cancers, especially high?grade OC and breast cancers. They lead to synthetic lethality in BRCA?mutated cells by stalling the replication forks in homologous recombination?deficient (HR) cells. Four PARP inhibitors (olaparib, niraparib, rucaparib, and talazoparib) are currently approved by the Food and Drug Administration for OC, breast, and pancreatic cancer indications and are being evaluated for other BRCA?associated cancers. Despite their clinical efficacy, cancer cells generally develop resistance to them through several mechanisms. Understanding these mechanisms is crucial for developing strategies to counter resistance and identify the basic mechanisms of DNA damage response. This review focuses on the mechanism of action of PARP inhibitors, understanding various causes of resistance, and building strategies to overcome PARP inhibitor resistance

Research progress on the relationship between DNA damage repair genes and liver cancer / 国际肿瘤学杂志

DNA damage repair (DDR) genes are overexpressed in liver cancer. Studies have found that DDR is closely related to the occurrence and development of liver cancer. There is a synergistic effect between DDR inhibitors and chemotherapy and targeted drugs for liver cancer. DDR inhibitors can enhance the sensitivity of radiotherapy. Some DDR genes can be used as biomarkers for the prognosis of liver cancer.

Predictive value of DNA repair gene expression for response to neoadjuvant chemotherapy in breast cancer

Genome-wide analysis using microarrays has revolutionized breast cancer (BC) research. A substantial body of evidence supports the clinical utility of the 21-gene assay (Oncotype DX) and 70-gene assay (MammaPrint) to predict BC recurrence and the magnitude of benefit from chemotherapy. However, there is currently no genetic tool able to predict chemosensitivity and chemoresistance to neoadjuvant chemotherapy (NACT) during BC treatment. In this study, we explored the predictive value of DNA repair gene expression in the neoadjuvant setting. We selected 98 patients with BC treated with NACT. We assessed DNA repair expression in 98 formalin-fixed, paraffin-embedded core biopsy fragments used at diagnosis and in 32 formalin-fixed, paraffin-embedded post-NACT residual tumors using quantitative reverse transcription-polymerase chain reaction. The following genes were selected: BRCA1, PALB2, RAD51C, BRCA2, ATM, FANCA, MSH2, XPA, ERCC1, PARP1, and SNM1. Of 98 patients, 33 (33.7%) achieved pathologic complete response (pCR). The DNA expression of 2 genes assessed in pre-NACT biopsies (PALB2 and ERCC1) was lower in pCR than in non-pCR patients (P=0.005 and P=0.009, respectively). There was no correlation between molecular subtype and expression of DNA repair genes. The genes BRCA2 (P=0.009), ATM (P=0.004), FANCA (P=0.001), and PARP1 (P=0.011) showed a lower expression in post-NACT residual tumor samples (n=32) than in pre-NACT biopsy samples (n=98). The expression of 2 genes (PALB2 and ERCC1) was lower in pCR patients. These alterations in DNA repair could be considered suitable targets for cancer therapy.

Effects of GNG4 on DNA damage repair and chemosensitivity of ovarian cancer cisplatin-resistant A2780/DDP cells / 肿瘤研究与临床

Objective:To investigate the correlation of GNG4 with DNA damage repair and chemosensitivity of ovarian cancer cisplatin-resistant A2780/DDP cells.Methods:A2780/DDP cells were divided into 500 ng/ml cisplatin group (cDDP group), short hairpin RNA (shRNA)-GNG4 silencing GNG4 expression group (shRNA group), 500 ng/ml cisplatin and shRNA-GNG4 intervention group (shRNA+cDDP group), and non cisplatin and shRNA-GNG4 intervention group (blank control group). Western blot was used to detect the expressions of GNG4 and γH2AX proteins in each group; DNA damage in each group was detected by single cell gel electrophoresis. The focus formation of γH2AX gene at the injury site was detected by immunofluorescence. The ability of cell clone formation was detected by plate clone formation experiment.Results:Compared with the other three groups, the expression level of GNG4 protein in shRNA+cDDP group was the lowest, the expression level of γH2AX protein was the highest, and the differences were statistically significant (all P < 0.01). Single cell gel electrophoresis assay showed that the comet tail DNA% in blank control group, cDDP group, shRNA group and shRNA+cDDP group were (7.7±2.5)%, (12.3±3.6)%, (20.1±2.1)%, (38.6±2.8)%, respectively, and Olive trailing distance were 5.12±1.89, 8.23±2.97, 14.99±3.65, 22.43±3.17, respectively, the comet tail DNA% and Olive tail distance in shRNA+cDDP group were higher than those in the other three groups, and the differences were statistically significant (all P < 0.05). Immunofluorescence assay showed that the focus numbers of γH2AX in each cell of blank control group, cDDP group, shRNA group and shRNA+cDDP group were 4.2±0.7, 5.1±0.5, 26.8±3.3, 71.3±6.2, respectively, the shRNA+cDDP group was higher than the other three groups, and the differences were statistically significant (all P < 0.05). The clone formation rates of blank control group, cDDP group, shRNA group and shRNA+cDDP group were (78.27±5.01)%, (45.67±3.29)%, (26.20±5.76)%, (1.56±0.21)%, respectively, the shRNA+cDDP group was lower than the other three groups, and the differences were statistically significant (all P < 0.001). Conclusions:Down-regulation of GNG4 expression can increase the cisplatin sensitivity of ovarian cancer A2780/DDP cells, which may be achieved by inhibiting the DNA damage repair function induced by cisplatin.

DNA Damage Repair System and Antineoplastic Agents in Lung Cancer / 中国肺癌杂志

DNA damage repair (DDR) system plays an important role in maintaining of genomic stability. Accumulation of DNA lesions or deficiency of DDR system could drive tumorigenesis as well as promote tumor progression; meanwhile, they could also provide therapeutic opportunities and targets. Of all the antineoplastic agents of lung cancers, many of them targeted or were associated with DNA damage and repair pathways, such as chemotherapies and antibody-drug conjugates which were designed directly causing DNA damages, targeted drugs inhibiting DNA repair pathways, and immune-checkpoint inhibitors. In this review, we described the role of DNA damage and repair pathways in antitumor activity of the above agents, as well as summarized the application and clinical investigations of these antineoplastic agents in lung cancers, in order to provide more information for exploring precision and effective strategies for the treatment of lung cancer based on the mechanism of DNA damage and repair.
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SET8 Inhibition Potentiates Radiotherapy by Suppressing DNA Damage Repair in Carcinomas / 生物医学与环境科学（英文）

Objective@#SET8 is a member of the SET domain-containing family and the only known lysine methyltransferase (KMT) that monomethylates lysine 20 of histone H4 (H4K20me1). SET8 has been implicated in many essential cellular processes, including cell cycle regulation, DNA replication, DNA damage response, and carcinogenesis. There is no conclusive evidence, however, regarding the effect of SET8 on radiotherapy. In the current study we determined the efficacy of SET8 inhibition on radiotherapy of tumors and the underlying mechanism.@*Methods@#First, we explored the radiotherapy benefit of the SET8 expression signature by analyzing clinical data. Then, we measured a series of biological endpoints, including the xenograft tumor growth in mice and apoptosis, frequency of micronuclei, and foci of 53BP1 and γ-H2AX in cells to detect the SET8 effects on radiosensitivity. RNA sequencing and subsequent experiments were exploited to verify the mechanism underlying the SET8 effects on radiotherapy.@*Results@#Low expression of SET8 predicted a better benefit to radiotherapy in lung adenocarcinoma (LUAD) and invasive breast carcinoma (BRCA) patients. Furthermore, genetic deletion of SET8 significantly enhanced radiation treatment efficacy in a murine tumor model, and A549 and MCF7 cells; SET8 overexpression decreased the radiosensitivity. SET8 inhibition induced more apoptosis, the frequency of micronuclei, and blocked the kinetics process of DNA damage repair as 53BP1 and γ-H2AX foci remained in cells. Moreover, RNF8 was positively correlated with the SET8 impact on DNA damage repair.@*Conclusion@#Our results demonstrated that SET8 inhibition enhanced radiosensitivity by suppressing DNA damage repair, thus suggesting that SET8 potentiated radiotherapy of carcinomas. As new inhibitors of SET8 are synthesized and tested in preclinical and clinical settings, combining SET8 inhibitors with radiation warrants consideration for precise radiotherapy.

Microcephaly-seizures-development delay syndrome in a pedigree: genetic analysis and literature review / 中华围产医学杂志

Objective:To analyze the phenotypes and genetic etiology of microcephaly- seizures-development delay (MCSZ) syndrome.Methods:The patient was diagnosed with MCSZ syndrome in June 2018 at Shenzhen Maternity and Child Healthcare Hospital. She was the couple's first child, and the mother conceived a second child in 2020. The clinical data of the proband were retrospectively analyzed, and the bioinformatics analysis and whole-exome sequencing (WES) were performed on the proband and her parents to identify the pathogenic variants, which were further validated using Sanger sequencing. The prenatal genetic diagnosis of the second fetus was performed following the molecular diagnosis of the proband was confirmed. The clinical manifestations and pathogenesis of MCSZ syndrome were summarized by reviewing related literature.Results:(1) Case report: The patient, an eight-month-old girl, was admitted to our hospital due to microcephaly and repeated seizures. Another clinical characteristic was mental retardation. Auditory evoked potential detected moderate impairment of the left auditory nerve pathway. WES showed a compound heterozygous variation in the PNKP gene of the proband. Moreover, the pathogenic variation, c.199-10_203delinsTCTGAGGGGT, was inherited from the father, and the likely pathogenic variation, c.1505C>T(p.P502>L), was inherited from the mother, which was both de novo mutations. The compound heterozygous variation in the PNKP gene was considered genetic etiology based on the genetic testing and clinical features. Prenatal diagnosis showed that the second fetus did not inherit the PNKP gene variants from the parents and the couples chose to continue the pregnancy. A girl was born, and her psychomotor development and occipitofrontal size circumference were normal at 13 months old. (2) Literature review: 39 MCSZ syndrome cases were retrieved, including the present case and 38 cases from 12 relevant literature. The clinical characteristics were microcephaly (91.7%, 33/36), seizures (88.2%, 30/34), development delay (96.4%, 27/28), hyperactivity (25.6%, 9/39), gastroesophageal reflux (10.3%, 4/39), and hearing loss (7.7%, 3/39). Most patients' first onset of epilepsy was in infancy (96.3%, 26/27). Cranial MRI examination showed brain dysplasia in 31 cases (91.2%, 31/34). Conclusions:When the fetal head circumference is smaller than normal and is progressively reduced combined with postnatal microcephaly, epilepsy, developmental retardation, hyperactivity disorder, gastroesophageal reflux, and hearing loss, MCSZ syndrome should be considered. The prognosis varies widely, and genetic testing facilitates the early diagnosis and genetic counseling of MCSZ syndrome.

ROLE OF DNA REPAIR IN AGING AND MALIGNANCY

DNA repair enzymes are proteins that detect and repair physical damage to DNA induced by radiation, ultraviolet light, or reactive oxygen species. The repair of DNA damage prevents the loss of genetic information, the creation of double-strand breaks, and the formation of DNA crosslinks. The time-dependent reduction of functional properties is known as aging. Mitochondrial malfunction and the buildup of genetic damage are two common factors of aging. In fact, the poor maintenance of nuclear and mitochondrial DNA is likely a major factor in aging. When the DNA repair machinery isn't operating fine, DNA lesions and mutations can occur, which can lead to cancer development. In fact, the poor maintenance of nuclear and mitochondrial DNA is likely a major factor in aging. When the DNA repair enzymes isn't operating fine, DNA lesions and mutations can occur, which can lead to cancer development. The large number of alterations per cell, which can reach 105, has been identified as a driving mechanism in oncogenesis. These findings show that abnormalities in the DNA repair pathway contribute to the senescence as well as cancer. Nucleotide excision repair (NER), base excision repair (BER), double-strand break repair, mismatch repair (MMR), are all major DNA repair processes in mammalian cells. BER excises mostly oxidative and alkylation DNA damage, NER removes bulky, helix-distorting lesions from DNA (e.g., ultraviolet (UV) photodimers), MMR corrects replication errors

Efeito Cardioprotetor da Suplementação Materna com Resveratrol sobre a Toxicidade Induzida por Doxorrubicina em Cardiomiócitos de Neonatos / Cardioprotective Effect of Maternal Supplementation with Resveratrol on Toxicity Induced by Doxorubicin in Offspring Cardiomyocytes

Resumo Fundamento A doxorrubicina (DOX) é frequentemente usada para tratar muitos tipos de cânceres, apesar da cardiotoxicidade dose-dependente. Como alternativa, o resveratrol é um polifenol que tem demonstrado efeitos cardioprotetores em vários modelos de disfunção cardíaca. Objetivo Este estudo investigou se o tratamento com resveratrol em ratas gestantes protege contra toxicidade induzida por doxorrubicina em cardiomiócitos da ninhada. Métodos Ratas Wistar (n-8) receberam sresveratrol como suplemento alimentar durante a gestação. No nascimento da ninhada, os corações (9-11) foram usados para se obter a cultura primária de cardiomiócitos. A cardiotoxicidade induzida por DOX e os efeitos da suplementação com resveratrol foram avaliados por marcadores de stress oxidativo, tais como oxidação da diclorofluoresceína diacetato, diminuição da atividade de enzimas antioxidantes, e oxidação do teor total de grupos sulfidrila, além da avaliação da viabilidade celular, geração de danos ao DNA, bem como a resposta de reparo aos danos ao DNA. Um valor de p <0,05 foi considerado estatisticamente significativo. Resultados Os cardiomiócitos de neonatos de ratas que receberam suplemento resveratrol apresentaram um aumento (p <0,01) na viabilidade das células, e diminuição (p <0,0001) de células apoptóticas/necróticas após o tratamento com DOX, o que está correlacionado às atividades de enzimas antioxidantes e produção de diclorofluoresceína. Além disso, o resveratrol protegeu os cardiomiócitos de danos ao DNA induzidos por DOX, apresentando uma diminuição (p <0,05) nas quebras de DNA induzidas por stress oxidativo, avaliadas pela atividade de enzimas reparadoras do DNA endonuclease III e formamidopirimidina glicosilase. A suplementação com resveratrol aumentou (p <0,05) a expressão da proteína reparadora Sirt6 nos cardiomiócitos dos filhotes. Conclusão Essa pesquisa indica que a suplementação com resveratrol durante o período gestacional tem um efeito cardioprotetor no coração da ninhada contra a toxicidade induzida por DOX, o que pode se dever a sua função antioxidante, e o aumento na resposta de danos ao DNA.

Abstract Background Doxorubicin (DOX) is frequently used to treat many types of cancers, despite its dose-dependent cardiotoxicity. Alternatively, resveratrol is a polyphenol that has shown useful cardioprotective effects in many heart dysfunction models. Objective This study investigated whether resveratrol treatment in pregnant rats protects against doxorubicin-induced toxicity in offspring cardiomyocytes. Methods Wistar rats (n=8) were supplemented with dietary resveratrol during pregnancy. Upon the offspring's birth, hearts (9-11) were used to obtain the primary culture of cardiomyocytes. DOX-induced cardiotoxicity and the effects of resveratrol supplementation were evaluated by oxidative stress markers, such as dichlorofluorescein diacetate oxidation, decrease in the activity of antioxidant enzymes, and oxidation of total sulfhydryl content, in addition to cell viability evaluation, DNA damage generation, and DNA damage repair response. A value of p<0.05 was considered statistically significant. Results Neonatal cardiomyocytes from resveratrol supplemented rats exhibiting an increase (p<0.01) in cell viability and lower (p<0.0001) apoptotic/necrotic cells after DOX treatment, which correlates with the activities of antioxidant enzymes and dichlorofluorescein production. Moreover, resveratrol protected cardiomyocytes from DOX-induced DNA damage, showing a decrease (p<0.05) in DNA breaks induced by oxidative stress, evaluated by the activity of DNA-repair enzymes endonuclease III and formamidopyrimidine glycosylase. Supplementation with resveratrol increased (p<0.05) the expression of the repair protein Sirt6 in the cardiomyocytes of the pups. Conclusion This research indicates that supplementation with resveratrol during the gestational period has a notable cardioprotective effect on the offspring's heart against DOX-induced toxicity, which may well be due to its antioxidant function, and the increase in the DNA damage repair response.

Inborn errors of immunity associated with characteristic phenotypes

Abstract Objectives: The aim of the report is to describe the main immunodeficiencies with syndromic characteristics according to the new classification of Inborn Errors of Immunity. Data source: The data search was centered on the PubMed platform on review studies, meta-analyses, systematic reviews, case reports and a randomized study published in the last 10 years that allowed the characterization of the several immunological defects included in this group. Data synthesis: Immunodeficiencies with syndromic characteristics include 65 immunological defects in 9 subgroups. The diversity of clinical manifestations is observed in each described disease and may appear early or later, with variable severity. Congenital thrombocytopenia, syndromes with DNA repair defect, immuno-osseous dysplasias, thymic defects, Hyper IgE Syndrome, anhidrotic ectodermal dysplasia with immunodeficiency and purine nucleoside phosphorylase deficiency were addressed. Conclusions: Immunological defects can present with very different characteristics; however, the occurrence of infectious processes, autoimmune disorders and progression to malignancy may suggest diagnostic research. In the case of diseases with gene mutations, family history is of utmost importance.

Value of DNA Repair Gene and TP53 Co-mutation in Predicting Effect of Immunotherapy on Lung Adenocarcinoma / 肿瘤防治研究

Objective To explore the value of DNA repair genes (DRGs) in predicting the effect of immunotherapy on lung adenocarcinoma based on second-generation sequencing technology. Methods The data of lung adenocarcinoma were obtained from the Cancer Genome Atlas, including the testing cohort and the validation cohort. In the testing set, according to the cut-off value of tumor mutational burden (TMB) score 15, the patients with lung adenocarcinoma were divided into two groups: the low TMB score group and the high TMB score group. And we analyzed the relation between TMB and the overall survival of lung adenocarcinoma patients. KRAS and TP53 co-mutation was used as the standard control, the differences in the mutation count and TMB score between only DRGs mutation group and KRAS or TP53 co-mutation groups were analyzed. In the validation cohort, the differences between DRGs and KRAS or TP53 co-mutation groups in TMB, tumor neoantigen burden and PFS were analyzed. Results The patients with TP53/DRGs co-mutation had higher mutation count and TMB score than those patients with only TP53 or DRGs mutation (P < 0.05). The patients with TP53/DRGs co-mutation had higher mutation count and TMB score than those patients with KRAS/TP53 co-mutation (P=0.037, P=0.044). In validation cohort analysis, the TP53/DRGs co-mutation patients also showed higher tumor neoantigens, higher TMB and longer progression-free survival than those patients with only TP53 or DRGs or KRAS/TP53 co-mutation groups. Conclusion TP53/DRGs co-mutation may be served as a pair of potential biomarkers for predicting the efficacy of immunotherapy on lung adenocarcinoma.

DNA damage repair and cell cycle arrest / 国际生物医学工程杂志

In the face of DNA damage caused by various factors, cells have a set of response and repair mechanisms. Cell cycle arrest plays an important role in the DNA damage repair, which provides enough time for repairing damaged DNA. Research on cell cycle regulation focuses on cyclin-dependent protein kinases (CDKs) and cell cycle checkpoints. In the process of DNA damage repair, phosphatidylinositol-3-kinase like kinases (PIKKs) which are recruited to the DNA damage sites can activate cell cycle checkpoint-related proteins to halt cell cycle. In the common DNA damage repair pathways, such as base excision repair (BER), nucleotide excision repair (NER) , mismatch repair (MMR) , and DNA double-strand break repair, the recruitment of repair-related proteins also plays a role in the cell cycle regulation. In this paper, the relationship between the main forms of DNA damage repair and cell cycle arrest and relevant research progress were reviewed.

In silico cloning, expression and bioinformatics analysis of NtODB from common tobacco / 生物工程学报

It has been reported that ODB genes play an important role in homologous recombination-directed DNA repair, suggesting their potential applications in plant breeding. To analyze the expression characteristics of tobacco NtODB gene, the cDNA sequence of NtODB was obtained using in silico cloning technique. The physicochemical properties, signal peptide, and advanced structures of the predicted protein were analyzed using bioinformatics tools. The results showed that the NtODB gene has a 579-bp open reading frame which encodes a protein with 192 amino acid residues. The protein NtODB is predicted to be alkaline and hydrophilic. Real-time quantitative PCR showed that NtODB was constitutively expressed in different tissues. Subcellular localization showed that NtODB was mainly expressed in cell membrane and chloroplast. These results may help us to better understand and elucidate the roles of ODB genes in the homologous recombination-directed DNA repair.