CIC-rearranged sarcoma: a clinicopathological analysis of four cases / 中华病理学杂志

Objective: To investigate the clinicopathological features and differential diagnosis of CIC-rearranged sarcoma (CRS). Methods: Five CRSs of 4 patients (2 biopsies of pelvic cavity and lung metastasis from case 4) diagnosed in the First Affiliated Hospital of Nanjing Medical University were enrolled from 2019 to 2021. All cases were evaluated by clinical presentation, H&E, immunohistochemical staining and molecular analysis and the related literature was reviewed. Results: There were one male and three females, the age at diagnosis ranged from 18 to 58 (mean 42.5) years. Three cases were from the deep soft tissues of the trunk and one case from the skin of foot. Grossly, the tumor size ranged from 1 to 16 cm. Microscopically, the tumor was arranged in nodules or solid sheets. The tumor cells were typically round or ovoid, with occasional spindled or epithelioid morphology. The nuclei were round to ovoid with vesicular chromatin and prominent nucleoli. Mitotic figures were brisk (>10/10 HPF). Rhabdoid cells were seen in four of five cases. Myxoid change and hemorrhage were observed in all samples and two cases showed geographic necrosis. Immunohistochemically, CD99 was variably positive in all samples, while WT1 and TLE-1 were positive in four of five samples. Molecular analysis showed CIC-rearrangements in all cases. Two patients succumbed within 3 months. One had mediastinal metastasis 9 months after surgery. One underwent adjuvant chemotherapy and remained tumor-free 10 months after diagnosis. Conclusions: CIC-rearranged sarcoma is uncommon and shows aggressive clinical course with dismal prognosis. The morphological and immunohistochemical characteristics can largely overlap with a variety of sarcomas; hence, knowledge of this entity is vital to avoid potential diagnostic pitfalls. Definitive diagnosis requires molecular confirmation of CIC-gene rearrangement.

Oculo-facio-cardio-dental syndrome caused by BCOR gene mutations: a case report / 中国当代儿科杂志

A full-term female infant was admitted at 5 hours after birth due to heart malformations found during the fetal period and cyanosis once after birth. Mmultiple malformations of eyes, face, limbs, and heart were noted. The whole-exome sequencing revealed a pathogenic heterozygous mutation, c.2428C>T(p.Arg810*), in the BCOR gene. The infant was then diagnosed with oculo-facio-cardio-dental syndrome. He received assisted ventilation to improve oxygenation and nutritional support during hospitalization. Right ventricular double outlet correction was performed 1 month after birth. Ocular lesions were followed up and scheduled for elective surgery. The possibility of oculo-facio-cardio-dental syndrome should be considered for neonates with multiple malformations of eyes, face, and heart, and genetic testing should be performed as early as possible to confirm the diagnosis; meanwhile, active ophthalmic and cardiovascular symptomatic treatment should be given to improve the prognosis.

Genetic analysis of a family with BCL11A-related intellectual disability / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for two patients from a family with BCL11A-related intellectual disability (BCL11A-ID).@*METHODS@#Clinical data of the proband and her family members was analyzed. Chromosomal karyotyping analysis, trio-whole exome sequencing (trio-WES) and copy number variation sequencing (CNV-seq) were carried out. For the suspected genetic variants, Sanger sequencing was used to verify, and pathogenicity assessment was conducted.@*RESULTS@#The proband and her mother both had intellectual and language impairment, and their fetal hemoglobin (HbF) was significantly elevated. A heterozygous c.1327_c.1328delTC (p.Ser443Hisfs*128) variant was found in exon 4 of the BCL11A gene by WES, which has resulted in truncated expression of the encoded protein, and Sanger sequencing has verified that the variant was inherited from the mother. The variant was not found in related databases. The variant was predicted as pathogenic according to the guidelines from the American College of Medical Genetics and Genomics (ACMG) (PVS1+PM2+PP1). No karyotypic abnormality was found in the proband, her parents and brother, and no pathogenic CNVs was found in the proband and her parents.@*CONCLUSION@#The c.1327_c.1328delTC (p.Ser443Hisfs*128) variant may underlay the BCL11A-ID in the proband and her mother. This de novo variant has expanded the mutational spectrum of the BCL11A gene.

Analysis of genotypes and phenotypes of three children with Cornelia de Lange syndrome / 中华医学遗传学杂志

OBJECTIVE@#To analyze the clinical phenotype and results of genetic testing in three children with Cornelia de Lange syndrome (CdLS).@*METHODS@#Clinical data of the children and their parents were collected. Peripheral blood samples of the pedigrees were collected for next generation sequencing analysis.@*RESULTS@#The main clinical manifestations of the three children have included growth delay, mental retardation, peculiar facies and other accompanying symptoms. Based on the criteria proposed by the International Diagnostic Consensus, all three children were suspected for CdLS. As revealed by whole exome sequencing, child 1 has harbored NIPBL gene c.5567_5569delGAA insTAT missense variant, child 2 has harbored SMC1A gene c.607A>G missense variant, and child 3 has harbored HDAC8 gene c.628+1G>A splicing variant. All of the variants were de novo in origin.@*CONCLUSION@#All of the children were diagnosed with CdLS due to pathogenic variants of the associated genes, among which the variants of NIPBL and HDAC8 genes were unreported previously. Above finding has enriched the spectrum of pathogenic variants underlying CdLS.

Clinical and genetic analysis of three children with KBG syndrome due to novel variants of ANKRD11 gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical and genetic characteristics of three children with KBG syndrome.@*METHODS@#Clinical data of the three children from two families who have presented at the First Affiliated Hospital of Zhengzhou University between October 2019 and September 2020 and their family members were collected. Trio-whole exome sequencing (trio-WES) and Sanger sequencing were carried out.@*RESULTS@#All children had feeding difficulties, congenital heart defects and facial dysmorphism. The sib- pair from family 1 was found to harbor a novel de novo heterozygous c.6270delT (p.Q2091Rfs*84) variant of the ANKRD11 gene, whilst the child from family 2 was found to harbor a novel heterozygous c.6858delC (p.D2286Efs*51) variant of the ANKRD11 gene, which was inherited from his mother who had a mild clinical phenotype.@*CONCLUSION@#The heterozygous frameshift variants of the ANKRD11 gene probably underlay the disease in the three children. Above findings have enriched the spectrum of the ANKRD11 gene variants.

The OxyR and SoxR transcriptional regulators are involved in a broad oxidative stress response in Paraburkholderia xenovorans LB400

BACKGROUND: Aerobic metabolism generates reactive oxygen species that may cause critical harm to the cell. The aim of this study is the characterization of the stress responses in the model aromatic degrading bacterium Paraburkholderia xenovorans LB400 to the oxidizing agents paraquat and H 2 O2. METHODS: Antioxidant genes were identified by bioinformatic methods in the genome of P. xenovorans LB400, and the phylogeny of its OxyR and SoxR transcriptional regulators were studied. Functionality of the transcriptional regulators from strain LB400 was assessed by complementation with LB400 SoxR of null mutant P. aeruginosa ΔsoxR, and the construction of P. xenovorans pIZ oxyR that overexpresses OxyR. The effects of oxidizing agents on P. xenovorans were studied measuring bacterial susceptibility, survival and ROS formation after exposure to paraquat and H 2 O2. The effects of these oxidants on gene expression (qRT PCR) and the proteome (LC-MS/MS) were quantified. RESULTS: P. xenovorans LB400 possesses a wide repertoire of genes for the antioxidant defense including the oxyR , ahpC , ahpF , kat , trxB , dpsA and gorA genes, whose orthologous genes are regulated by the transcriptional regulator OxyR in E. coli . The LB400 genome also harbors the soxR, fumC , acnA , sodB , fpr and fldX genes, whose orthologous genes are regulated by the transcriptional regulator SoxR in E. coli . The functionality of the LB400 soxR gene was confirmed by complementation of null mutant P. aeruginosa Δ soxR . Growth, susceptibility, and ROS formation assays revealed that LB400 cells were more susceptible to paraquat than H2O2. Transcriptional analyses indicated the upregulation of the oxyR , ahpC1 , katE and ohrB genes in LB400 cells after exposure to H2O2, whereas the oxyR , fumC , ahpC1 , sodB1 and ohrB genes were induced in presence of paraquat. Proteome analysis revealed that paraquat induced the oxidative stress response proteins AhpCF and DpsA, the universal stress protein UspA and the RNA chaperone CspA. Both oxidizing agents induced the Ohr protein, which is involved in organic peroxide resistance. Notably, the overexpression of the LB400 oxyR gene in P. xenovorans significantly decreased the ROS formation and the susceptibility to paraquat, suggesting a broad OxyR regulated antioxidant response. CONCLUSIONS: This study showed that P. xenovorans LB400 possess a broad range oxidative stress response, which explain the high resistance of this strain to the oxidizing compounds paraquat and H2O2.

Analysis of three patients with KBG syndrome and epileptic seizures due to variants of ANKRD11 gene / 中华医学遗传学杂志

OBJECTIVE@#To summarize the clinical phenotype and genotypic characteristics of 3 patients with KBG syndrome and epileptic seizure.@*METHODS@#Clinical data of the patients were collected. Family-trio whole exon sequencing (WES) was carried out. Candidate variants were verified by Sanger sequencing.@*RESULTS@#Patients 1 and 2 were boys, and patient 3 was an adult woman. All patients had epileptic seizures and mental deficiency. Their facial features included triangular face, low hair line, hypertelorism, large forward leaning auricles, broad nasal bridge, upturned nostrils, long philtrum, arched upper lip, and macrodontia. The two boys also had bilateral Simian creases. WES revealed that the three patients all harbored heterozygous de novo frameshift variants in exon 9 of the ANKRD11 gene including c.2948delG (p.Ser983Metfs*335), c.5397_c.5398insC (p.Glu1800Argfs*150) and c.1180_c.1184delAATAA (p.Asn394Hisfs*42). So far 291 patients with ANKRD11 gene variants or 16q24.3 microdeletions were reported, with over 75% being de novo mutations.@*CONCLUSION@#Above findings have enriched the spectrum of ANKRD11 gene mutations underlying KBG syndrome. WES is helpful for the early diagnosis of KBG, and provided reference for genetic counseling of this disease.

Gender difference in clinical manifestations of KBG syndrome due to variants of ANKRD11 gene / 中华医学遗传学杂志

OBJECTIVE@#To explore gender difference in the clinical manifestations of two children with Keishi-Bukuryo-Gan syndrome (KBGS).@*METHODS@#Clinical manifestations of the two children were reviewed. Genetic testing was carried out through next generation sequencing (NGS). Treatment was summarized, and the prognosis was followed up.@*RESULTS@#Both children showed particular appearance including megatooth, abnormal hair distribution, hands' abnormality and language development delay. NGS revealed that both children have carried pathogenic variants of the ANKRD11 gene (c.1903_1907del and c.4911delT), which resulted in shifting of amino acid sequences starting from the Lysine and Proline at positions 635 and 1638, respectively. The female patient exhibited central precocious puberty. Her height has increased by 13 cm, and sex characteristics has retracted after treatment with leuprorelin for 23 months and recombinant human growth hormone for 1 month.@*CONCLUSION@#Comparison of the two cases with different genders and summary of previously reported cases found that male KBGS patients have more obvious dysmorphisms such as triangular face, synophrys, ocular hypertelorism and vertebral body abnormality, with higher morbidity of epilepsy, mental retardation, autism, congenital heart disease, immune thrombocytopenia and other complications. KBGS is an autosomal dominant disease featuring more evident peculiar appearance and global development delay. Male patients often have multi-system involvement, and multidisciplinary cooperation is required for early recognition of particular features in order to improve the prognosis.

The role of nuclear receptor transcription factor NR2F6 in tumor / 生物工程学报

Nuclear receptor subfamily 2, group F, member 6 (NR2F6) is a member of orphan nuclear receptors, which is expressed in major tissues and organs of the human body, and plays an important role in the regulation of various biological functions and gene expressions. Recent studies have shown that the expression of NR2F6 was up-regulated in a variety of malignant tumors and showed significant correlations with cancer progression. These findings triggered the widespread interest in understanding the relationship between NR2F6 and cancer development and progression. In addition, the latest studies have underscored that NR2F6 was involved in enhancing antitumor immune responses that could serve as a potential target for immune regulation. This review summarizes the biological functions of NR2F6 and its role in tumors, with the aim to provide new insights into effective cancer therapies.

Clinical Characteristics and Prognosis of Acute Myeloid Leukemia Patients with ASXL1 Gene Mutation / 中国实验血液学杂志

OBJECTIVE@#To investigate the clinical characteristics and prognosis of acute myeloid leukemia(AML) patients with ASXL1 mutation.@*METHODS@#The clinical data of 229 newly diagnosed AML patients treated in our hospital from April 2016 to October 2019 were analyzed retrospectively. The next-generation sequencing technology was used to detect gene mutations in all the patients, the clinical characteristics of the patients with ASXL1 mutation were analyzed.@*RESULTS@#ASXL1 gene mutation was detected out in 45 patients(19.6%). Among these patients, the frameshift mutation (n=22,48.9%) was most common, followed by missense mutation (n=15, 33.3%) and nonsense mutation (n=8,17.8%), respectively, all of them were located at exon 12. The median mutation rate was 32.47%(range, 2.74%-53.50%). The median age of the patients with ASXL1 mutation was 54(range, 14-74) years old, and most of the patients were male, and most of them with the history of MDS or MPN, and low white blood cell count at the initial diagnosed (P<0.05). Patients with ASXL1 mutation showed a lower CR rate than that of without ASXL1 mutation. Patients with or without ASXL1 mutation showed a statistically significant difference in survival at 20 months (P=0.042), while there was no significant difference between the patients in the two groups over 20 months (P=0.505). All the 6 patients with ASXL1 mutation in low-risk group were survived, while the median OS time was 16 months in the high-risk group(P=0.034). Multivariate analysis showed that the history of MDS or MPN and CR rate from induction therapy were the independent risk factors affecting survival of the patients.@*CONCLUSION@#Frameshift mutation is commonly in AML patients with ASXL1 gene mutation, and ASXL1 mutation were more often in men, the history of MDS or MPN, and low white blood cell count. The CR rate of the patients with ASXL1 mutation was lower than that of the AML patients without ASXL1 mutations, AML patients with ASXL1 mutation showed poor short-term efficacy, but there was no significant difference between the two groups in long-term survival over 20 months.

Clinical features and genetic analysis of three children with mental retardation, language impairment and autistic features due to de novo variants of FOXP1 gene / 中华医学遗传学杂志

OBJECTIVE@#To analyze the clinical features and genetic basis of three children with mental retardation, language impairment and autistic features due to de novo variants of FOXP1 gene.@*METHODS@#Clinical data of the children were collected.Trio-whole exome sequencing was carried out for the children and their parents. Pathogenicity of the variants was analyzed through bioinformatics prediction.@*RESULTS@#All of the children had various degrees of mental retardation in conjunct with language deficit, global developmental delay, abnormal behavior and peculiar facial features, among whom two also developed autism spectrum disorders. The results of genetic testing showed that all three children harbored de novo variants of the FOXP1 gene, namely c.613_c.614delCTinsTA, c.1248delC and c.1393A>G. Two of these were frameshift variants and one was missense variant, which were all rated as pathogenic based on the guidelines of the American College of Medical Genetics (ACMG). Database search suggested that c.613_c.614delCTinsTA and c.1248delC were unreported previously.@*CONCLUSION@#For the three children from unrelated families with mental retardation in conjunct with language deficit, global growth delay, abnormal behavior and peculiar facial features, the c.613_ c. 614delCTinsTA, c.1248delC and c.1393A>G variants of the FOXP1 gene may be the pathogenic factors. Above cases have further expanded the genotype-phenotype profile of FOXP1 deficiency syndrome.

Construction and phenotypic study of Pseudomonas aeruginosa inducibly expressing a ferric uptake regulator / 生物工程学报

Members of the ferric uptake regulator (Fur) protein family are bacterial transcriptional repressors that control iron uptake and storage in response to iron availability, thereby playing a crucial role in the maintenance of iron homeostasis. The fur null mutants of Pseudomonas aeruginosa could not be obtained because fur is an essential gene. In this study, We constructed a Fur inducibly expression strain Δfur/attB::PBAD-fur in order to study the effect of fur on the growth, biofilm formation, motilities and oxidative stress response of P. aeruginosa. The results showed that a low level of fur expression retarded the growth of P. aeruginosa at an iron-depleted condition, or under high concentration of iron, or in the presence of H2O2. Fur affected the biofilm formation and the motilities (swimming, twitching, and swarming) of strain PAO1. The production of pyoverdine is regulated by Fur. Interestingly, proteins from Magnetospirillum gryphiswaldense MSR-1, which shares homology with Fur, can partially recover the pyoverdine production of strain Δfur/attB::PBAD-fur. This study provides new clues for the prevention and treatment of P. aeruginosa infections.

Progress in Gene Therapy of Sickle Cell Disease Based on Hemoglobin F--Review / 中国实验血液学杂志

Sickle cell disease (SCD) is a single gene genetic disease, which seriously threatens the life span and quality of patients. On the basis of the pathogenesis of SCD and the alternative therapy based on fetal hemoglobin F (HbF), the research progress of transcription factors involved in the regulation of HbF gene expression, such as BCL11A, ZBTB7A, KLF-1, c-MYB and SOX6, as well as the application of CRISPR / Cas9, TALEN, zinc finger nuclease and other gene editing technologies in this field has been made, providing a solid theoretical basis for the exploration of new treatment schemes for β- like hemoglobin diseases, such as sickle cell disease and β- thalassemia.

The Relationship between ASXL2 and ZBTB7A Gene Mutations and Prognosis in Patients with Acute Myeloid Leukemia / 中国实验血液学杂志

OBJECTIVE@#To investigate the relationship between acute myeloid leukemia (AML) patients ASXL2, ZBTB7A gene mutations and the prognosis.@*METHODS@#42 AML Patients treated in our hospital from January 2014 to January 2016 were selected and ASXL2 and ZBTB7A genes of their bone marrow samples were sequenced, the genetic characteristics and prognosis of core-binding factor-AML(CBF-AML) patients with ASXL2 and ZBTB7A mutations were analyzed.@*RESULTS@#ASXL2 (33.3%) and ZBTB7A (9.5%) mutations were found in t (8; 21) AML patients. Compared with wild-type, patients with ASXL2 mutations showed significantly higher white blood cell count at diagnosis ［(9.49±1.85)×10@*CONCLUSION@#ASXL2 and ZBTB7A mutations are frequently found in t (8; 21) AML patients. The mutation of ASXL2 and ZBTB7A genes shows no significant effect on the prognosis of AML patients.

Improvement of polyhydroxybutyrate production by deletion of csrA in Escherichia coli

BACKGROUND: Poly-3-hydroxybutyrate (PHB) can be efficiently produced in recombinant Escherichia coli by the overexpression of an operon (NphaCAB) encoding PHB synthetase. Strain improvement is considered to be one of critical factors to lower the production cost of PHB in recombinant system. In this study, one of key regulators that affect the cell growth and PHB content was confirmed and analyzed. RESULT: S17-3, a mutant E. coli strain derived from S17-1, was found to be able to achieve high cell density when expressing NphaCAB with the plasmid pBhya-CAB. Whole genome sequencing of S17-3 revealed genetic alternations on the upstream regions of csrA, encoding a global regulator cross-talking between stress response, catabolite repression and other metabolic activities. Deletion of csrA or expression of mutant csrA resulted in improved cell density and PHB content. CONCLUSION: The impact of gene deletion of csrA was determined, dysfunction of the regulators improved the cell density of recombinant E. coli and PHB production, however, the detail mechanism needs to be further clarified.

Clinical Characteristics and Prognostic Significance of BCOR/BCORL1 Gene Mutation in Patients with Myelodysplastic Syndromes / 中国实验血液学杂志

OBJECTIVE@#To investigate the clinical characteristics and prognostic significance of myelodysplastic syndrome (MDS) patients with BCOR/BCORL1 mutation.@*METHODS@#The clinical characteristics of 135 patients diagnosed as de novo MDS in People's Hospital of Xinjiang Uygur Autonomous Region from September 2015 to September 2019 were analyzed retrospectively. Next-generation sequencing was used to detect 34 kinds of myeloid-tumor-related gene in MDS patients. The clinical characteristics of BCOR/BCORL1 mutation and its effect to progression-free survival(PSF) and overall survival (OS) in MDS patients were analyzed.@*RESULTS@#Among MDS patients, BCOR/BCORL1 mutation was found in 34(25.2%) patients, including 16(11.9%) BCOR mutation and 18(13.3%) BCORL1 mutation. Patients with BCOR/BCORL1 mutation were more common in women and showed lower neutrophil count ［0.75(0.08-22.20) vs 1.27(0.06-35.71)×10@*CONCLUSION@#BCOR/BCORL1 mutation is more common in MDS patients and often company with other genes co-mutations. BCOR/BCORL1 mutation is not associated with disease progression and AML transformation in MDS patients, but it predicts poor overall survival.

Detection and analysis of dynamic variant in a pedigree affected with spinocerebellar ataxia type 3 / 中华医学遗传学杂志

OBJECTIVE@#To analyze the dynamic variant and clinical subtype of a pedigree affected with spinocerebellar ataxia (SCA) by using fluorescent-labeled primer combined with capillary electrophoresis.@*METHODS@#Genomic DNA was extracted from 8 members including 6 patients and 2 healthy individuals from the pedigree. Six pairs of fluorescent-labeled primers were designed to screen pathological variants in association with common subtypes of SCA including SCA1, SCA2, SCA3, SCA6, SCA12 and SCA17.The PCR products were detected by capillary electrophoresis.@*RESULTS@#The number of CAG repeats in the SCA3 gene of the proband were determined as 8 and 70, exceeded the normal range(12 to 40), which suggested a diagnosis of SCA3. The other five patients were all detected with abnormal CAG repeats in the SCA3 gene, while the two healthy individuals were determined to be within the normal range.@*CONCLUSION@#The abnormal expansion of CAG repeats in the SCA3 gene probably underlay the pathogenesis of the disease in this pedigree. Combined fluorescent-labeled primers PCR and capillary electrophoresis can detect dynamic variants among SCA patients with efficiency and accuracy.

Methylation status of the PPP1R13L promoter region among lung cancer patients and healthy controls. Analytical cross-sectional study

ABSTRACT BACKGROUND: There is evidence that genetic predisposition and epigenetic alteration (e.g. DNA methylation) play major roles in lung cancer. In our genetic epidemiological studies, rs1970764 in oncogene PPP1R13L was most consistently associated with lung cancer risk. Here, we explored the role of PPP1R13L methylation in lung cancer development. DESIGN AND SETTING: Analytical cross-sectional study (45 lung cancer cases and 45 controls), conducted in China. METHODS: We investigated the DNA methylation status of 2,160 cytosine-phosphate-guanine (CpG) sites in the PPP1R13L promoter region using the EpiTYPER assay of the Sequenom MassARRAY platform. RESULTS: In the whole study group, the methylation levels of CpG-6, CpG-9, CpG-20 and CpG-21 were significantly lower and those of CpG-16 were significantly higher in cases than in controls. Among smokers, the methylation levels at five CpG sites (CpG-6, CpG-11, CpG-15, CpG-20 and CpG-21) were statistically significantly lower among cases. Among men, the methylation levels at four CpG sites (CpG-11, CpG-15, CpG-20 and CpG-21) were significantly lower among cases. Regarding smokers, the methylation levels at CpG-7.8 and CpG-21 among cases and at CpG-22 among controls were significantly lower, compared with nonsmokers. The frequency of positivity for methylation was not significantly different between lung cancer cases and controls (68.22% for cases and 71.87% for controls; P = 0.119). CONCLUSION: Our study on a Chinese population suggests that lung cancer patients have aberrant methylation status (hypomethylation tended to be more frequent) in peripheral blood leukocytes at several CpG sites in the PPP1R13L promoter region and that exposure to smoking may influence methylation status.

Inactivation of MarR gene homologs increases susceptibility to antimicrobials in Bacteroides fragilis

ABSTRACT Bacteroides fragilis is the strict anaerobic bacteria most commonly found in human infections, and has a high mortality rate. Among other virulence factors, the remarkable ability to acquire resistance to a variety of antimicrobial agents and to tolerate nanomolar concentrations of oxygen explains in part their success in causing infection and colonizing the mucosa. Much attention has been given to genes related to multiple drug resistance derived from plasmids, integrons or transposon, but such genes are also detected in chromosomal systems, like the mar (multiple antibiotic resistance) locus, that confer resistance to a range of drugs. Regulators like MarR, that control expression of the locus mar, also regulate resistance to organic solvents, disinfectants and oxygen reactive species are important players in these events. Strains derived from the parental strain 638R, with mutations in the genes hereby known as marRI (BF638R_3159) and marRII (BF638R_3706) were constructed by gene disruption using a suicide plasmid. Phenotypic response of the mutant strains to hydrogen peroxide, cell survival assay against exposure to oxygen, biofilm formation, resistance to bile salts and resistance to antibiotics was evaluated. The results showed that the mutant strains exhibit statistically significant differences in their response to oxygen stress, but no changes were observed in survival when exposed to bile salts. Biofilm formation was not affected by either gene disruption. Both mutant strains however, became more sensitive to multiple antimicrobial drugs tested. This indicates that as observed in other bacterial species, MarR are an important resistance mechanism in B. fragilis.

Diagnostic utility of DREAM gene mRNA levels in thyroid tumours

ABSTRACT Objective The transcriptional repressor DREAM is involved in thyroid-specific gene expression, thyroid enlargement and nodular development, but its clinical utility is still uncertain. In this study we aimed to investigate whether DREAM mRNA levels differ in different thyroid tumors and how this possible difference would allow the use of DREAM gene expression as molecular marker for diagnostic and/or prognosis purpose. Materials and methods We quantified DREAM gene mRNA levels and investigated its mutational status, relating its expression and genetic changes to diagnostic and prognostic features of 200 thyroid tumors, being 101 malignant [99 papillary thyroid carcinomas (PTC) and 2 anaplastic thyroid carcinomas] and 99 benign thyroid lesions [49 goiter and 50 follicular adenomas (FA)]. Results Levels of mRNA of DREAM gene were higher in benign (0.7909 ± 0.6274 AU) than in malignant (0.3373 ± 0.6274 AU) thyroid lesions (p < 0.0001). DREAM gene expression was able to identify malignancy with 66.7% sensitivity, 85.4% specificity, 84.2% positive predictive value (PPV), 68.7% negative predictive value (NPV), and 75.3% accuracy. DREAM mRNA levels were also useful distinguishing the follicular lesions FA and FVPTC with 70.2% sensitivity, 73.5% specificity, 78.5% PPV, 64.1% NPV, and 71.6% accuracy. However, DREAM gene expression was neither associated with clinical features of tumor aggressiveness, nor with recurrence or survival. Six different genetic changes in non-coding regions of DREAM gene were also found, not related to DREAM gene expression or tumor features. Conclusion We suggest that DREAM gene expression may help diagnose thyroid nodules, identifying malignancy and characterizing follicular-patterned thyroid lesions; however, it is not useful as a prognostic marker.