Severe irinotecan-induced toxicity in a patient with UGT1A1*28 and UGT1A1*6 polymorphisms

Many studies have demonstrated the impact of UGT1A1 on toxicity of irinotecan. In particular, patients bear-ing UGT1A1*28 (TA 7/7) have a higher risk of severe neutropenia and diarrhea. Based on this, prescribers of irinotecan are advised that patients with UGT1A1*28 (TA 7/7) should start with a reduced dose of irinotecan, although a particular dose is not specified. Research in Asian countries has shown a lower incidence of UG-T1A1*28 (TA 7/7), while UGT1A1*6 (A/A) is more often found and is associated with severe irinotecan-related neutropenia. We report here a case of a metastatic colorectal cancer patient who is heterozygous for the UGT1A1*28 polymorphism (TA 6/7) as well as the UG-T1A1*6 polymorphism (G/A). The patient was treated with FOLFIRI for 9 cycles and underwent two irinote-can dose reductions according to pharmacokinetic data regarding exposure to the active metabolite, SN-38. Simultaneous heterozygous UGT1A1*28 and UGT1A1*6 polymorphisms may produce higher exposure to SN-38 and a higher risk of adverse effects related to irinote-can. Additional studies will be necessary to determine the optimal starting dose of irinotecan for patients with both UGT1A1*28 and UGT1A1*6 polymorphisms.     

Control of seed mass and seed yield by the floral homeotic gene APETALA2

APETALA2 (AP2) is best known for its role in the regulation of flower meristem and flower organ identity and development in Arabidopsis. We show here that AP2 also plays an important role in determining seed size, seed weight, and the accumulation of seed oil and protein. We demonstrate genetically that AP2 acts through the maternal sporophyte and endosperm genomes to control seed weight and seed yield. Thus, AP2 functions outside the boundaries of flower meristem and flower organ development to affect agronomically relevant traits in Arabidopsis.     

Association between polymorphisms of APE1 and OGG1 and risk of colorectal cancer in Taiwan

AIM: To evaluate the effects of OGG1(Ser326Cys, 11657A/G, and Arg154His) and APE1(Asp148Glu, and T-656G) polymorphisms on colorectal cancer(CRC) risk.METHODS: We enrolled 727 cases newly diagnosed with colorectal adenocarcinoma and 736 age- and sex-matched healthy controls from a medical center in Taiwan. Genomic DNA isolated from the buffy coat was used for genotyping through polymerase chain reaction. Unconditional logistic regressions were used for calculating ORs and 95%CIs to determine the association between the genetic polymorphisms and CRC risk. Haplotype frequencies were estimated using PHASE software. Moreover, stratification analyses onthe basis of sex, age at diagnosis, and tumor subsite and stage were performed.RESULTS: The CRC risk was higher in patients with the OGG1 326Ser/Cys + Cys/Cys genotype(OR = 1.38, 95%CI: 1.03-1.85, P = 0.030), particularly high in patients with stage Ⅲ + Ⅳ cancer(OR = 1.48, 95%CI: 1.03-2.13) compared with patients with the Ser/Ser genotype. In addition, OGG1 11657 G allele carriers had a 41% reduced CRC risk among stage 0-Ⅱ patients(OR = 0.59, 95%CI: 0.35-0.98). The CRC risk was significantly higher among females with the APE1 Glu allele(OR = 1.41, 95%CI: 1.02-1.96). The APE1 148Glu/-656 G haplotype was also associated with a significant CRC risk in females(OR = 1.36, 95%CI: 1.03-1.78).CONCLUSION: OGG1 and APE1 polymorphisms are associated with stage- and sex-specific risk of CRC in the Taiwanese population.     

MT1M and MT1G promoter methylation as biomarkers for hepatocellular carcinoma

AIM:To investigate the potential of promoter methylation of two tumor suppressor genes(TSGs)as biomarkers for hepatocellular carcinoma(HCC).METHODS:A total of 189 subjects were included in this retrospective cohort,which contained 121 HCC patients without any history of curative treatment,37 patients with chronic hepatitis B(CHB),and 31 normal controls(NCs).DNA samples were extracted from 400μL of serum of each subject and then modified using bisulfite treatment.Methylation of the promoters of the TSGs(metallothionein1M,MT1M;and metallothionein 1G,MT1G)was determined using methylation-specific polymerase chain reaction.The diagnostic value of combined MT1M and MT1G promoter methylation was evaluated using the area under the receiver operating characteristic curves.RESULTS:Our results indicated that the methylation status of serum MT1M(48.8%,59/121)and MT1G(70.2%,85/121)promoters in the HCC group was significantly higher than that in the CHB group(MT1M 5.4%,2/37,P<0.001;MT1G 16.2%,6/37,P<0.001)and NC group(MT1M 6.5%,2/31,P<0.001;MT1G 12.9%,4/27,P<0.001).Aberrant serum MT1M promoter methylation gave higher specificity to discriminate HCC from CHB(94.6%)and NCs(93.5%),whereas combined methylation of serum MT1M and MT1G promoters showed higher diagnostic sensitivity(90.9%),suggesting that they are potential markers for noninvasive detection of HCC.Furthermore,MT1M promoter methylation was positively correlated with tumor size(rs=0.321,P<0.001),and HCC patients with both MT1M and MT1G promoter methylation tended to show a higher incidence of vascular invasion or metastasis(P=0.018).CONCLUSION:MT1M and MT1G promoter methylation may be used as serum biomarkers for noninvasive detection of HCC.     

Evidence that CRABS CLAW and TOUSLED have conserved their roles in carpel development since the ancestor of the extant angiosperms

The carpel is the female reproductive organ specific to flowering plants. We aim to define the genes that controlled carpel development in the common ancestor of this group as a step toward determining the molecular events that were responsible for the evolution of the carpel. CRABS CLAW (CRC) and TOUSLED (TSL) control important aspects of carpel development in the model plant, Arabidopsis thaliana. The basal angiosperm species Amborella trichopoda and Cabomba aquatica very likely represent the two most early diverging groups of flowering plants. We have identified putative orthologues of CRC and TSL from A. trichopoda and C. aquatica, respectively. We demonstrate the expression patterns of these genes in carpels to be very highly conserved, both spatially and temporally, with those of their Arabidopsis orthologues. We argue that CRC and TSL in Arabidopsis are likely to have conserved their respective roles in carpel development since the common ancestor of the living flowering plants. We conclude that a divergent role shown for the CRC orthologue in rice, DROOPING LEAF, most probably arose specifically in the monocot lineage. We show that, in addition to its expression in carpels, the TSL orthologue of C. aquatica is expressed in tissues that contribute to buoyancy and argue that its role in these tissues may have arisen later than its role in carpel development.     

Mutations of PHF6 are associated with mutations of NOTCH1, JAK1 and rearrangement of SET-NUP214 in T-cell acute lymphoblastic leukemia

Background

Mutations in the PHF6 gene were recently described in patients with T-cell acute lymphoblastic leukemia and in those with acute myeloid leukemia. The present study was designed to determine the prevalence of PHF6 gene alterations in T-cell acute lymphoblastic leukemia.

Design and Methods

We analyzed the incidence and prognostic value of PHF6 mutations in 96 Chinese patients with T-cell acute lymphoblastic leukemia. PHF6 deletions were screened by real-time quantitative polymerase chain reaction and array-based comparative genomic hybridization. Patients were also investigated for NOTCH1, FBXW7, WT1, and JAK1 mutations together with CALM-AF10, SET-NUP214, and SIL-TAL1 gene rearrangements.

Results

PHF6 mutations were identified in 11/59 (18.6%) adult and 2/37 (5.4%) pediatric cases of T-cell acute lymphoblastic leukemia, these incidences being significantly lower than those recently reported. Although PHF6 is X-linked and mutations have been reported to occur almost exclusively in male patients, we found no sex difference in the incidences of PHF6 mutations in Chinese patients with T-cell acute lymphoblastic leukemia. PHF6 deletions were detected in 2/79 (2.5%) patients analyzed. NOTCH1 mutations, FBXW7 mutations, WT1 mutations, JAK1 mutations, SIL-TAL1 fusions, SET-NUP214 fusions and CALM-AF10 fusions were present in 44/96 (45.8%), 9/96 (9.4%), 4/96 (4.1%), 3/49 (6.1%), 9/48 (18.8%), 3/48 (6.3%) and 0/48 (0%) of patients, respectively. The molecular genetic markers most frequently associated with PHF6 mutations were NOTCH1 mutations (P=0.003), SET-NUP214 rearrangements (P=0.002), and JAK1 mutations (P=0.005). No differences in disease-free survival and overall survival between T-cell acute lymphoblastic leukemia patients with and without PHF6 mutations were observed in a short-term follow-up.

Conclusions

Overall, these results indicate that, in T-cell acute lymphoblastic leukemia, PHF6 mutations are a recurrent genetic abnormality associated with mutations of NOTCH1, JAK1 and rearrangement of SET-NUP214.     

The longevity effect of cranberry extract in Caenorhabditis elegans is modulated by daf-16 and osr-1

Nutraceuticals are known to have numerous health and disease preventing properties. Recent studies suggest that extracts containing cranberry may have anti-aging benefits. However, little is known about whether and how cranberry by itself promotes longevity and healthspan in any organism. Here we examined the effect of a cranberry only extract on lifespan and healthspan in Caenorhabditis elegans. Supplementation of the diet with cranberry extract (CBE) increased the lifespan in C. elegans in a concentration-dependent manner. Cranberry also increased tolerance of C. elegans to heat shock, but not to oxidative stress or ultraviolet irradiation. In addition, we tested the effect of cranberry on brood size and motility and found that cranberry did not influence these behaviors. Our mechanistic studies indicated that lifespan extension induced by CBE requires the insulin/IGF signaling pathway and DAF-16. We also found that cranberry promotes longevity through osmotic stress resistant-1 (OSR-1) and one of its downstream effectors, UNC-43, but not through SEK-1, a component of the p38 MAP kinase pathway. However, SIR-2.1 and JNK signaling pathways are not required for cranberry to promote longevity. Our findings suggest that cranberry supplementation confers increased longevity and stress resistance in C. elegans through pathways modulated by daf-16 and osr-1. This study reveals the anti-aging property of widely consumed cranberry and elucidates the underpinning mechanisms.     

Synergistic effect of Bcl2, Myc and Ccnd1 transforms mouse primary B cells into malignant cells

Background

A synergistic effect resulting from a combination of BCL2 and MYC or MYC and CCND1 has been implicated in human B-cell lymphomas. Although the identification of other cooperative genes involved is important, our present understanding of such genes remains scant. The objective of this study was to identify the additional cooperative gene(s) associated with BCL2 and MYC or MYC and CCND1. First, we assessed whether Bcl2, Myc and Ccnd1 could cooperate. Next, we developed a synergism-based functional screening method for the identification of other oncogene(s) that act with Bcl2 and Myc.

Design and Methods

Growth in culture, colony formation and oncogenicity in vivo were assessed in mouse primary B cells exogenously expressing various combinations of Bcl2, Myc and Ccnd1. For the functional screening, Bcl2- and Myc-expressing primary B cells were infected with a retroviral cDNA library. Inserted cDNA of transformed cells in culture were then identified.

Results

Primary B cells exogenously expressing Bcl2, Myc and Ccnd1 showed factor-independent growth ability, enhanced colony-forming capability and aggressive oncogenicity, unlike the cases observed with the expression of any combination of only two of the genes. We identified CCND3 and NRAS as cooperative genes with Bcl2 and Myc through the functional screening.

Conclusions

Bcl2, Myc and Ccnd1 or Bcl2, Myc and CCND3 synergistically transformed mouse primary B cells into aggressive malignant cells. Our new synergism-based method is useful for the identification of synergistic gene combinations in tumor development, and may expand our systemic understanding of a wide range of cancer-causing elements.     

Mutations in topoisomerase I as a self-resistance mechanism coevolved with the production of the anticancer alkaloid camptothecin in plants

Plants produce a variety of toxic compounds, which are often used as anticancer drugs. The self-resistance mechanism to these toxic metabolites in the producing plants, however, remains unclear. The plant-derived anticancer alkaloid camptothecin (CPT) induces cell death by targeting DNA topoisomerase I (Top1), the enzyme that catalyzes changes in DNA topology. We found that CPT-producing plants, including Camptotheca acuminata, Ophiorrhiza pumila, and Ophiorrhiza liukiuensis, have Top1s with point mutations that confer resistance to CPT, suggesting the effect of an endogenous toxic metabolite on the evolution of the target cellular component. Three amino acid substitutions that contribute to CPT resistance were identified: Asn421Lys, Leu530Ile, and Asn722Ser (numbered according to human Top1). The substitution at position 722 is identical to that found in CPT-resistant human cancer cells. The other mutations have not been found to date in CPT-resistant human cancer cells; this predicts the possibility of occurrence of these mutations in CPT-resistant human cancer patients in the future. Furthermore, comparative analysis of Top1s of CPT-producing and nonproducing plants suggested that the former were partially primed for CPT resistance before CPT biosynthesis evolved. Our results demonstrate the molecular mechanism of self-resistance to endogenously produced toxic compounds and the possibility of adaptive coevolution between the CPT production system and its target Top1 in the producing plants.     

The developmental selector AS1 is an evolutionarily conserved regulator of the plant immune response

The MYB-related gene ASYMMETRIC LEAVES 1 (AS1) and its orthologs have an evolutionarily conserved role in specification of leaf cell identity. AS1 is expressed in leaf founder cells, where it functions as a heterodimer with the structurally unrelated AS2 proteins to repress activity of KNOTTED 1-like homeobox (KNOX) genes. AS1 therefore confines KNOX activity to the shoot apical meristem, where it promotes stem cell function through the regulation of phytohormone activities. Here, we show that loss-of-function mutations in AS1 unexpectedly convey heightened protection against necrotrophic fungi. AS1 operates as a negative regulator of inducible resistance against these pathogens by selectively binding to the promoters of genes controlled by the immune activator, jasmonic acid (JA), damping the defense response. In contrast, AS1 is a positive regulator of salicylic acid (SA)-independent extracellular defenses against bacterial pathogens. Neither the absence of AS2 nor ERECTA function, which enhances the morphological phenotype of as1, nor the conditional or constitutive expression of KNOX genes impacted disease resistance. Thus, the function of AS1 in responses to phytopathogens is independent of its AS2-associated role in development. Loss of function in the AS1 orthologs PHAN in Antirrhinum majus and NSPHAN in Nicotiana sylvestris produced pathogen-response phenotypes similar to as1 plants, and therefore the defense function of AS1 is evolutionarily conserved in plant species with a divergence time of approximately 125 million years.     

Toxicity effect of Delonix elata (Yellow Gulmohr) and predatory efficiency of Copepod,Mesocyclops aspericornis for the control of dengue vector,Aedes aegypti

Objective

To evaluate the toxicity, predatory efficiency of Delonix elata (D. elata) and Mesocyclops aspericornis (M. aspericornis) against dengue vector, Aedes aegypti (Ae. aegypti).

Methods

A mosquitocidal bioassay was conducted at different concentration of plant extract followed by WHO standard method. The probit analysis of each tested concentration and control were observed by using software SPSS 11 version package. The each tested concentration variable was assessed by DMRT method. The predatory efficiency of copepod was followed by Deo et al., 1988. The predator, M. aspericornis was observed for mortality, abnormalities, survival and swimming activity after 24 h treatment of plant and also predation on the mosquito larvae were observed.

Results

D. elata were tested for biological activity against the larvae, and pupae of Ae. aegypti. Significant mortality effects were observed in each life stage. The percentage of mortality was 100% in first and second instars whereas 96%, 92% in third and fourth instars. Fitted probit-mortality curves for larvae indicated the median and 90% lethal concentrations of D. elata for instars 1-4 to be 4.91 (8.13), 5.16 (8.44), 5.95 (7.76) and 6.87 (11.23), respectively. The results indicate that leaf extract exhibits significant biological activity against life stages. The present study revealed that D. elata is potentially important in the control of Ae. aegypti. Similar studies were conducted for predatory efficiency of Copepod, M. aspericornis against mosquito vector Ae. Aegypti. This study reported that the predatory copepod fed on 39% and 25% in I and III instar larvae of mosquito and in combined treatment of D. elata and copepod maximum control of mosquito larval states and at 83%, 80%, 75% and 53% in I, II, III and IV instars, respectively.

Conclusions

The combined action of plant extract and predatory copepod to effectively control mosquito population and reduce the dengue transmitting diseases.     

Developmental hyperbilirubinemia and CNS toxicity in mice humanized with the UDP glucuronosyltransferase 1 (UGT1) locus

High levels of unconjugated bilirubin (UCB) in newborn children is associated with a reduction in hepatic UDP glucuronosyltransferase (UGT) 1A1 activity that can lead to CNS toxicity, brain damage, and even death. Little is known regarding those events that lead to UCB accumulation in brain tissue, and therefore, we sought to duplicate this condition in mice. The human UGT1 locus, encoding all 9-UGT1A genes including UGT1A1, was expressed in Ugt1^−/− mice. Because the most common clinical condition associated with jaundice in adults is Gilbert’s syndrome, which is characterized by an allelic polymorphism in the UGT1A1 promoter, hyperbilirubinemia was monitored in humanized UGT1 mice that expressed either the Gilbert’s UGT1A1*28 allele [Tg(UGT1^A1*28)Ugt1^−/− mice] or the normal UGT1A1*1 allele [Tg(UGT1^A1*1)Ugt1^−/− mice]. Adult Tg(UGT1^A1*28)Ugt1^−/− mice expressed elevated levels of total bilirubin (TB) compared with Tg(UGT1^A1*1)Ugt1^−/− mice, confirming that the promoter polymorphism associated with the UGT1A1*28 allele contributes to hyperbilirubinemia in mice. However, TB accumulated to near toxic levels during neonatal development, a finding that is independent of the Gilbert’s UGT1A1*28 promoter polymorphism. Whereas serum TB levels eventually returned to adult levels, TB clearance in neonatal mice was not associated with hepatic UGT1A1 expression. In ∼10% of the humanized UGT1 mice, peak TB levels culminated in seizures followed by death. UCB deposition in brain tissue and the ensuing seizures were associated with developmental milestones and can be prevented by enhancing regulation of the UGT1A1 gene in neonatal mice.     

Genomic analysis of para-Bombay individuals in south-eastern China: the possibility of linkage and disequilibrium between FUT1 and FUT2

BackgroundThe para-Bombay phenotype results from a variety of mutations in the α-(1,2)-fucosyltransferase gene (FUT1). We investigated samples from seven Chinese probands serologically typed as having the para-Bombay phenotype.ResultsThree FUT1 genotypes, h1/h1 (5 individuals), h1/h6 (1 individual) and h3/h2 (1 individual), and three FUT2 genotypes, Se³⁵⁷/Se³⁵⁷ (5 individuals), Se³⁵⁷/Se^{357, 385} (1 individual) and Se³⁵⁷/Se^{357, 716} (1 individual) were observed in seven para-Bombay probands. Among 331 donors, only one individual carried the G716A and 880delTT mutations in heterozygosity; this subjects FUT1 and FUT2 genotypes were H/h2 and Se³⁵⁷/Se^{357, 716}, respectively.ConclusionThe review of all para-Bombay probands identified in the Fujian Blood Centre showed that h1 and h2 are the predominant non-functional FUT1 alleles in Fujian para-Bombay individuals. Our data confirm the hypothesis that the h2 allele is linked to Se^{357, 716}, and the concurrence of unique FUT1 and FUT2 mutations is geographically specific.     

Discordance between changes in the gut microbiota and pathogenicity in a mouse model of spontaneous colitis

Under conventional conditions, mice deficient in core 1-derived O-glycans (TM-IEC C1galt1^−/−), which have a defective mucus layer, experienced spontaneous inflammation of the colon. Analysis of fecal bacterial populations by pyrosequencing of 16S rRNA gene showed that disease in conventional TM-IEC C1galt1^−/− was associated with shifts in the microbiota manifested by increases in Lactobacillus and Clostridium species, and decreases in unclassified Ruminococcaceae and Lachnospiraceae. Under germ-free (GF) conditions, TM-IEC C1galt1^−/− presented decreased goblet cells, but did not develop inflammation. Monoassociation of GF TM-IEC C1galt1^−/− revealed that bacterial species differ significantly in their ability to induce inflammatory changes. Bacteroides thetaiotaomicron caused inflammation, while Lactobacillus johnsonii (enriched during colitis) did not. These observations demonstrate that not all microbiota shifts that correlate with disease contribute to pathogenesis.     

Comparative study of mutations in SNP loci of K-RAS,hMLH1 and hMSH2 genes in neoplastic intestinal polyps and colorectal cancer

AIM: To clarify the molecular mechanism involved in pathogenesis of colorectal cancer as well as clinical significance of genetic analysis of histological samples.METHODS: A total of 480 blood and tissue specimens were collected in our hospital from January 2011 to October 2012. In the observation group, there were 120 blood specimens and 120 intestinal tract tissue specimens collected from patients with neoplastic intestinal polyps. In the control group I there were 80 blood specimens and 80 intestinal tract tissue specimens collected from patients with colorectal cancer. In the control group II there were 40 blood specimens and 40 intestinal tract tissue specimens collected from healthy individuals. The gene segments were amplified using PCR and DNA gel electrophoresis along with DNA sequence analysis were employed for the detection of the following single nucleotide polymorphisms (SNPs): K-RAS codons 12 and 13; hMLH1 (human mutS homolog 1) gene missense mutation at Va1384Asp; hMSH2 (human mutS homolog 2) gene missense mutation at 2783C/A.RESULTS: The mutation rate of the SNP at Va1384Asp locus of the hMLH1 gene from blood and tissue specimens in the observation group showed no statistical difference from those in the control group I. The mutation rates of SNPs in codons 12 and 13 of K-RAS and at 2783C/A locus of the hMSH2 gene were significantly lower in the observation group than in the control group I (χ² = 15.476, 29.670, 10.811, 16.618, 33.538, 7.898, P < 0.05). The mutation rate of SNP at Va1384Asp locus of the hMLH1 gene was significantly higher in the observation group when compared to the control group II (χ² = 10.486, 4.876, P < 0.05). The mutation rates of SNPs in codons 12 and 13 of K-RAS and at 2783C/A locus of the hMSH2 gene did not show any statistical difference from those in the control group II.CONCLUSION: There may be important clinical significance and relevance between neoplastic intestinal polyps and colorectal cancer in terms of the mechanisms involved in the pathogenesis.     

Structural insight into the reaction mechanism and evolution of cytokinin biosynthesis

The phytohormone cytokinin regulates plant growth and development. This hormone is also synthesized by some phytopathogenic bacteria, such as Agrobacterium tumefaciens, and is as a key factor in the formation of plant tumors. The rate-limiting step of cytokinin biosynthesis is catalyzed by adenosine phosphate-isopentenyltransferase (IPT). Agrobacterium IPT has a unique substrate specificity that enables it to increase trans-zeatin production by recruiting a metabolic intermediate of the host plant's biosynthetic pathway. Here, we show the crystal structures of Tzs, an IPT from A. tumefaciens, complexed with AMP and a prenyl-donor analogue, dimethylallyl S-thiodiphosphate. The structures reveal that the carbon-nitrogen-based prenylation proceeds by the SN2-reaction mechanism. Site-directed mutagenesis was used to determine the amino acid residues, Asp-173 and His-214, which are responsible for differences in prenyl-donor substrate specificity between plant and bacterial IPTs. IPT and the p loop-containing nucleoside triphosphate hydrolases likely evolved from a common ancestral protein. Despite structural similarities, IPT has evolved a distinct role in which the p loop transfers a prenyl moiety in cytokinin biosynthesis.