Utility and limitations of hepascore and transient elastography to detect advanced hepatic fibrosis in HFE hemochromatosis

Aspartate aminotransferase-to-platelet ratio index (APRI) and Fibrosis-4 Index (Fib4) have been validated against liver biopsy for detecting advanced hepatic fibrosis in HFE hemochromatosis. We determined the diagnostic utility for advanced hepatic fibrosis of Hepascore and transient elastography compared with APRI and Fib4 in 134 newly diagnosed HFE hemochromatosis subjects with serum ferritin levels \u3e 300 µg/L using area under the receiver operator characteristic curve (AUROC) analysis and APRI- ( \u3e 0.44) or Fib4- ( \u3e 1.1) cut-offs for AHF, or a combination of both. Compared with APRI, Hepascore demonstrated an AUROC for advanced fibrosis of 0.69 (95% CI 0.56–0.83; sensitivity = 69%, specificity = 65%; P = 0.01) at a cut-off of 0.22. Using a combination of APRI and Fib4, the AUROC for Hepascore for advanced fibrosis was 0.70 (95% CI 0.54–0.86, P = 0.02). Hepascore was not diagnostic for detection of advanced fibrosis using the Fib4 cut-off. Elastography was not diagnostic using either APRI or Fib4 cut-offs. Hepascore and elastography detected significantly fewer true positive or true negative cases of advanced fibrosis compared with APRI and Fib4, except in subjects with serum ferritin levels \u3e 1000 µg/L. In comparison with APRI or Fib4, Hepascore or elastography may underdiagnose advanced fibrosis in HFE Hemochromatosis, except in individuals with serum ferritin levels \u3e 1000 µg/L

Copy Number Variation Affecting the Photoperiod-B1 and Vernalization-A1 Genes Is Associated with Altered Flowering Time in Wheat (Triticum aestivum)

The timing of flowering during the year is an important adaptive character affecting reproductive success in plants and is critical to crop yield. Flowering time has been extensively manipulated in crops such as wheat (Triticum aestivum L.) during domestication, and this enables them to grow productively in a wide range of environments. Several major genes controlling flowering time have been identified in wheat with mutant alleles having sequence changes such as insertions, deletions or point mutations. We investigated genetic variants in commercial varieties of wheat that regulate flowering by altering photoperiod response (Ppd-B1 alleles) or vernalization requirement (Vrn-A1 alleles) and for which no candidate mutation was found within the gene sequence. Genetic and genomic approaches showed that in both cases alleles conferring altered flowering time had an increased copy number of the gene and altered gene expression. Alleles with an increased copy number of Ppd-B1 confer an early flowering day neutral phenotype and have arisen independently at least twice. Plants with an increased copy number of Vrn-A1 have an increased requirement for vernalization so that longer periods of cold are required to potentiate flowering. The results suggest that copy number variation (CNV) plays a significant role in wheat adaptation

Genetic and environmental effects on crop development determining adaptation and yield

Slafer, Gustavo Ariel. ICREA - AGROTECNIO - Spain.Kantolic, Adriana Graciela. Universidad de Buenos Aires. Facultad de Agronomía. Buenos Aires, Argentina.Appendino, María Laura. Universidad de Buenos Aires. Facultad de Agronomía. Buenos Aires, Argentina.Tranquilli, Gabriela Edith. Instituto Nacional de Tecnología Agropecuaria (INTA). Recursos Naturales. Instituto de Recursos Biológicos. Buenos Aires, Argentina.Miralles, Daniel Julio. Universidad de Buenos Aires. Facultad de Agronomía. Buenos Aires, Argentina.Savin, Roxana. ICREA - AGROTECNIO - Spain.Crop development is a sequence of phenological events controlled by the genetic background and influenced by external factors, which determines changes in the morphology and/or function of organs (Landsberg, 1977). Although development is a continuous process, the ontogeny of a crop is frequently divided into discrete periods, for instance ‘vegetative’, ‘reproductive’ and ‘grain - filling’ phases (Slafer, 2012). Patterns of phenological development largely determine the adaptation of a crop to a certain range of environments. For example, genetic improvement in grain yield of wheat has been associated with shorter time from sowing to anthesis in Mediterranean environments of western Australia (Siddique et al., 1989), whereas no consistent trends in phenology were found where drought is present but not necessarily terminal, including environments of Argentina, Canada and the USA (Slafer and Andrade, 1989, 1993; Slafer et al., 1994a) (Fig. 12.1). Even in agricultural lands of the Mediterranean Basin where wheat has been grown for many centuries, breeding during the last century did not clearly change phenological patterns (Acreche et al., 2008). This chapter focuses on two major morphologically and hysiologically contrasting grain crops: wheat and soybean. For both species, we have an advanced understanding of development and physiology in general. Wheat is a determinate, long-day grass of temperate origin, which is responsive to vernalization. Soybean is a typically indeterminate (but with determinate intermediate variants), short-day grain legume of tropical origin, which is insensitive to vernalization. Comparisons with other species are used to highlight the similarities and differences. The aims of this chapter are to outline the developmental characteristics of grain crops and the links between phenology and yield, to revise the mechanisms of environmental and genetic control of development and to explore the possibilities of improving crop adaptation and yield potential through the fine-tuning of developmental patterns

Flavopiridol Pharmacogenetics: Clinical and Functional Evidence for the Role of SLCO1B1/OATP1B1 in Flavopiridol Disposition

Flavopiridol is a cyclin-dependent kinase inhibitor in phase II clinical development for treatment of various forms of cancer. When administered with a pharmacokinetically (PK)-directed dosing schedule, flavopiridol exhibited striking activity in patients with refractory chronic lymphocytic leukemia. This study aimed to evaluate pharmacogenetic factors associated with inter-individual variability in pharmacokinetics and outcomes associated with flavopiridol therapy.Thirty-five patients who received single-agent flavopiridol via the PK-directed schedule were genotyped for 189 polymorphisms in genes encoding 56 drug metabolizing enzymes and transporters. Genotypes were evaluated in univariate and multivariate analyses as covariates in a population PK model. Transport of flavopiridol and its glucuronide metabolite was evaluated in uptake assays in HEK-293 and MDCK-II cells transiently transfected with SLCO1B1. Polymorphisms in ABCC2, ABCG2, UGT1A1, UGT1A9, and SLCO1B1 were found to significantly correlate with flavopiridol PK in univariate analysis. Transport assay results indicated both flavopiridol and flavopiridol-glucuronide are substrates of the SLCO1B1/OATP1B1 transporter. Covariates incorporated into the final population PK model included bilirubin, SLCO1B1 rs11045819 and ABCC2 rs8187710. Associations were also observed between genotype and response. To validate these findings, a second set of data with 51 patients was evaluated, and overall trends for associations between PK and PGx were found to be consistent.Polymorphisms in transport genes were found to be associated with flavopiridol disposition and outcomes. Observed clinical associations with SLCO1B1 were functionally validated indicating for the first time its relevance as a transporter of flavopiridol and its glucuronide metabolite. A second 51-patient dataset indicated similar trends between genotype in the SLCO1B1 and other candidate genes, thus providing support for these findings. Further study in larger patient populations will be necessary to fully characterize and validate the clinical impact of polymorphisms in SLCO1B1 and other transporter and metabolizing enzyme genes on outcomes from flavopiridol therapy

A non-canonical function of topoisomerase II in disentangling dysfunctional telomeres

The decatenation activity of topoisomerase II (Top2), which is widely conserved within the eukaryotic domain, is essential for chromosomal segregation in mitosis. It is less clear, however, whether Top2 performs the same function uniformly across the whole genome, and whether all its functions rely on decatenation. In the fission yeast, Schizosaccharomyces pombe, telomeres are bound by Taz1, which promotes smooth replication fork progression through the repetitive telomeric sequences. Hence, replication forks stall at taz1Δ telomeres. This leads to telomeric entanglements at low temperatures (⩽20°C) that cause chromosomal segregation defects and loss of viability. Here, we show that the appearance of entanglements, and the resulting cold sensitivity of taz1Δ cells, is suppressed by mutated alleles of Top2 that confer slower catalytic turnover. This suppression does not rely on the decatenation activity of Top2. Rather, the enhanced presence of reaction intermediates in which Top2 is clamped around DNA, promotes the removal of telomeric entanglements in vivo, independently of catalytic cycle completion. We propose a model for how the clamped enzyme–DNA complex promotes proper chromosomal segregation

A phase II, open-label study of tomivosertib (eFT508) added on to continued checkpoint inhibitor therapy in patients (pts) with insufficient response to single-agent treatment.

Background: Despite the broad activity of checkpoint inhibitors across tumor types, primary or secondary resistance after initial response represents a major challenge. Tomivosertib (T), a potent and highly selective inhibitor of the immunosuppressive kinases MNK-1 and 2, blocks expression of checkpoint proteins PD-1, PD-L1, and LAG-3 as well as immunosuppressive cytokines IL-6 and IL-8. In preclinical models, T was shown to trigger an anti-tumor immune response and enhance the activity of checkpoint inhibitors in a T-cell dependent manner. In prior clinical studies, T had an acceptable safety profile as a single agent and in combination with anti-PD-L1 agent avelumab. Methods: Patients experiencing insufficient response (progression or stable disease for 12 weeks or more) to any FDA-approved checkpoint inhibitor in any approved indication were eligible. T at 200 mg oral (PO) BID was added to the existing checkpoint inhibitor until disease progression or unacceptable toxicity was noted. Results: 39 pts (23 male, 16 female) were enrolled across seven cancer types. Median age was 68 (range 42-85). Median prior therapies were 2 (range 1-6). The most common cancers were lung (N = 17), urothelial (N = 6), renal (N = 5) and head and neck (N = 5). 36 pts continued on anti PD-1 antibody (Pembrolizumab and Nivolumab, 18 each) and 3 on anti PD-L-1 antibody (Durvalumab 2, Atezolizumab 1) . The most common grade 3/4 treatment related adverse events occurring in more than 1 pt were alanine aminotransferase increase (2), blood creatine phosphokinase increase (2) and maculo-papular rash (2). 7 patients discontinued treatment (18%) due to adverse events attributable to either drug. Three partial responses (PR) per RECIST 1.1 were observed in pts with previous progression on checkpoint inhibitor therapy, one each in NSCLC (1/17), gastric (1/1) and renal cancer (1/5). 7 NSCLC pts (41%) were progression free for ≥ 24 weeks. All NSCLC patients entered the study with progression by RECIST 1.1 on single agent checkpoint inhibitor prior to adding T. Conclusions: The addition of T to existing checkpoint therapy was well tolerated and manifested clinical activity including objective responses in pts with progression on existing checkpoint inhibitor. A Progression Free Survival rate at 24 weeks of 41% was noted in NSCLC patients. Additional studies evaluating the addition of T to checkpoint inhibitor therapy after progression on anti PD-1 or PD-L-1 therapy are planned. Clinical trial information: NCT03616834