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Purpose: P-glycoprotein (Pgp) is a major prognostic factor for chemotherapy failure in acute myeloid leukemia (AML). This study compared the influence of genetic and leukemia-specific factors on Pgp.Experimental Design: Eight hundred and seventeen samples were studied prospectively for Pgp protein expression and function and G1199A, G2677T, and C3435T polymorphisms in the encoding gene ABCB1.Results: Age, low WBC count, high bcl-2, secondary AML and myelodysplastic syndrome, and adverse cytogenetics all correlated strongly with high Pgp (MRK16) protein expression. However, ABCB1 3435TT homozygosity was negatively correlated with Pgp. Pgp protein is only expressed in 41% of samples such that the negative effect of the polymorphism was not seen at baseline Pgp levels but was marked in the upper 41% of samples (MRK16 Δmean fluorescence intensity of 75th centile sample = 9 units for TT variant samples and 26 units for CC/CT; P = 0.003). However, no association was found between genetic factors and Pgp function using rhodamine 123 accumulation.Conclusions: The genetic polymorphism 3435TT (which results in unstable mRNA) has a significant effect on Pgp expression, but this is only seen in ∼40% of cases in which mRNA and protein are detectable. Moreover, leukemia-specific factors, such as low WBC count and poor risk cytogenetics, have a much greater effect than genetic polymorphisms on Pgp expression in AML blasts.

Supplementary Data from Sequential Influences of Leukemia-Specific and Genetic Factors on P-Glycoprotein Expression in Blasts from 817 Patients Entered into the National Cancer Research Network Acute Myeloid Leukemia 14 and 15 Trials

Secondary acute myeloid leukaemia (AML) has a poor outcome following "3 + 7-like" chemotherapy. While CPX-351 has been approved for patients aged 60-75, the optimal treatment, or comparator, in younger patients is less clear. The MRC AML15 trial randomised younger patients between daunorubicin and ara-C (DA) and DA plus etoposide (ADE) and ADE and fludarabine, cytarabine, idarubicin, and granulocyte colony-stimulating factor (FLAG-Ida) induction. Overall results failed to show an overall survival benefit for FLAG-Ida despite a reduction in relapse, the outcome of patients60 years with secondary AML compared to DA/ADE was not reported. In this group (n = 115) response to induction was not different [complete remission/complete remission with incomplete haematological response 81% vs. 79%), however, 5-year overall survival and relapse free survival was superior for FLAG-Ida [37% vs. 27%, stratified hazard ratio (HR) 0·45 (0·33-0·90) P = 0·02 and 41% vs. 22%; stratified HR 0·54 (0·31-0·96) P = 0·04] respectively, suggesting that younger patients with secondary AML may benefit from treatment intensification and that "3 + 7" may not be the optimal comparator in trials for this group of patients.

Acute myeloblastic leukaemia arises in a haematopoietic stem cell as a result of mutations which promote growth or inhibit apoptosis in association with mutations that inhibit differentiation. There is usually no obvious cause, but exposure to chemical and ionizing radiation may be relevant, including previous chemotherapy for solid tumours. This leukaemia arises particularly in older patients, often in the context of antecedent haematological disorders such as myelodysplastic syndromes or myeloproliferative neoplasms. Clinical features are of marrow failure, with anaemia, bleeding (petechiae, purpura, from mucous membranes), and infection. Acute promyelocytic leukaemia should be viewed as a medical emergency characterized by disseminated intravascular coagulation which requires urgent treatment to avoid haemorrhagic death. Aside from providing appropriate supportive care, the first clinical decision to be made is whether to give conventional intensive chemotherapy aiming for disease eradication, or to adopt a more palliative approach. Intensive chemotherapy is the norm up to age 65 to 70 years. Above this age, the biology of the disease tends to be less favourable and patients may have significant comorbidities limiting treatment tolerance. In patients under 60 years, 75 to 80% will achieve initial remission and about 45 to 50% will survive. In older patients given intensive treatment, 50 to 60% will enter remission but only 15 to 20% will survive 2 years. With nonintensive treatments, remissions are seen in 15 to 25% with the median survival being 6 to 9 months. Relapsed disease—more than 50% of patients will ultimately relapse and their overall outcome is generally very poor. The best curative option is allogeneic stem cell transplantation if a second complete remission can be achieved with reinduction chemotherapy.

Abstract 91 In normal and leukemic hemopoiesis, stem cells differentiate through intermediate progenitors into terminal cells. In human Acute Myeloid Leukemia (AML), there is uncertainty about: (i) whether there is more than one leukemic stem cell (LSC) population in any one individual patient; (ii) how homogeneous AML LSCs populations are at a molecular and cellular level and (iii) the relationship between AML LSCs and normal stem/progenitor populations. Answers to these questions will clarify the molecular pathways important in the stepwise transformation of normal HSCs/progenitors. We have studied 82 primary human CD34+ AML samples (spanning a range of FAB subtypes, cytogenetic categories and FLT3 and NPM1 mutation states) and 8 age-matched control marrow samples. In ∼80% of AML cases, two expanded populations with hemopoietic progenitor immunophenotype coexist in most patients. One population is CD34+CD38-CD90-CD45RA+ (CD38-CD45RA+) and the other CD34+CD38+CD110-CD45RA+ (GMP-like). Both populations from 7/8 patients have leukemic stem cell (LSC) activity in primary and secondary xenograft assays with no LSC activity in CD34- compartment. The two CD34+ LSC populations are hierarchically ordered, with CD38-CD45RA+ LSC giving rise to CD38+CD45RA+ LSC in vivo and in vitro. Limit dilution analysis shows that CD38-CD45RA+LSCs are more potent by 8–10 fold. From 18 patients, we isolated both CD38-CD45RA+ and GMP-like LSC populations. Global mRNA expression profiles of FACS-sorted CD38-CD45RA+ and GMP-like populations from the same patient allowed comparison of the two populations within each patient (negating the effect of genetic/epigenetic changes between patients). Using a paired t-test, 748 genes were differentially expressed between CD38-CD45RA+ and GMP-like LSCs and separated the two populations in most patients in 3D PCA. This was confirmed by independent quantitative measures of difference in gene expression using a non-parametric rank product analysis with a false discovery rate of 0.01. Thus, the two AML LSC populations are molecularly distinct. We then compared LSC profiles with those from 4 different adult marrow normal stem/progenitor cells to identify the normal stem/progenitor cell populations which the two AML LSC populations are most similar to at a molecular level. We first obtained a 2626 gene set by ANOVA, that maximally distinguished normal stem and progenitor populations. Next, the expression profiles of 22 CD38-CD45RA+ and 21 GMP-like AML LSC populations were distributed by 3D PCA using this ANOVA gene set. This showed that AML LSCs were most closely related to their normal counterpart progenitor population and not normal HSC. This data was confirmed quantitatively by a classifier analysis and hierarchical clustering. Taken together, the two LSC populations are hierarchically ordered, molecularly distinct and their gene expression profiles do not map most closely to normal HSCs but rather to their counterpart normal progenitor populations. Finally, as global expression profiles of CD38-CD45RA+ AML LSC resemble normal CD38-CD45RA+ cells, we defined the functional potential of these normal cells. This had not been previously determined. Using colony and limiting dilution liquid culture assays, we showed that single normal CD38-CD45RA+ cells have granulocyte and macrophage (GM), lymphoid (T and B cell) but not megakaryocyte-erythroid (MK-E) potential. Furthermore, gene expression studies on 10 cells showed that CD38-CD45RA+ cells express lymphoid and GM but not Mk-E genes. Taken together, normal CD38-CD45RA+ cells are most similar to mouse lymphoid primed multi-potential progenitor cells (LMPP) cells and distinct from the recently identified human Macrophage Lymphoid progenitor (MLP) population. In summary, for the first time, we show the co-existence of LMPP-like and GMP-like LSCs in CD34+ AML. Thus, CD34+ AML is a progenitor disease where LSCs have acquired abnormal self-renewal potential (Figure 1). Going forward, this work provides a platform for determining pathological LSCs self-renewal and tracking LSCs post treatment, both of which will impact on leukemia biology and therapy. Disclosures: No relevant conflicts of interest to declare.

It is believed that acute myeloblastic leukaemia arises in a haematopoietic stem cell as a result of mutations which promote growth or inhibit apoptosis arising in association with mutations that inhibit differentiation. In most cases there is no obvious cause, but exposure to chemical and ionizing radiation may be relevant, including previous chemotherapy for solid tumours....

This article, brought to you in association with Help the Aged, looks at the difficulties involved in using public transport for the older person. Help the Aged is calling for a flexible transport system which provides a free bus pass or travel tokens depending on what works for individuals.

In this article, brought to you in association with Help the Aged, Alan Burnett examines the causes of fear of crime among older people, and proposes ways to reduce it.

The emphasis of this chapter is on the local political role played in recent years by one major British urban university. The focus is also on political interaction between the University of Portsmouth and Portsmouth City Council. The electoral significance of the university, and in particular the student vote in the south of the city, is examined as are the multi-faceted relations between gown, town and city hall. During the 1990s these relations have been characterised by elements of both co-operation and conflict, the latter mainly concerned with tensions associated with the recent expansion of the university.

Abstract 3525 Leukaemic transformation is driven by aberrant transcriptional programs often in combination with abnormal proliferative signalling. These programs operate in normal hematopoiesis where they are involved in hematopoietic stem cell (HSC) proliferation and maintenance. ERG is a component of normal and leukemic stem cell signatures and high ERG expression has been proposed as a risk factor for poor prognosis in acute myeloid leukemia (AML). However, mechanisms that underlie ERG expression in AML and how its expression relates to leukemic stemness are unknown. We report that ERG expression in AML is associated with activity of the ERG+85 stem cell enhancer (SCE) and a heptad of transcription factors that combinatorially regulate genes in normal HSCs. Gene expression signatures derived from ERG+85 stem cell enhancer (Fig A) and heptad activity (Fig B) predict clinical outcome in a cytogenetically normal cohort of AML (CN-AML) patients when ERG expression alone fails. The heptad signature is an independent risk factor for poor overall and event-free survival (Fig C). There were no long-term survivors amongst patients with a heptad signature, FLT3 mutations and wild-type NPM1 (Fig D) pointing to a hitherto unappreciated link between aberrant signaling and transcriptional mediators of hematopoietic stem cell identity. In two independent cohorts, the heptad signature was as closely associated with wild-type NPM1 AML as the HOX signature was with mutant NPM1 AML (Fig E–F) suggestive of a collective role for these transcription factors in mediating the leukemic signature in the former. Taken together, these results show that key transcriptional regulators cooperate in establishing stem cell signatures in leukemic cells and that the underlying spectrum of somatic mutations contributes to the development of these signatures and modulate their influence on clinical outcome. Disclosures: No relevant conflicts of interest to declare.

(1996). Book Review: Steve Hoadley, New Zealand and Australia: Negotiating Closer Economic Relations (Wellington: New Zealand Institute of International Affairs, 1995), pp. vi, 134, $19.95. Political Science: Vol. 48, No. 1, pp. 123-124.

Based on experimentally generated data such as thermal and transformation strains, temperature-dependent elastic-plastic properties, time-dependent thermal profiles, and core and case chemistry, this paper traces the stress history and development of residual stress fields in case-hardened carburized-steel cylinders from the onset to the final stages of quenching. Results were obtained by the use of a modified thermoelastic-plastic finite-element procedure. Special emphasis was given to establishing quantitatively the degree of involvement of the temperature fields associated with the heat treatment, plastic flow, austenite-to-body-centered-tetragonal phase transformation, and case and core chemistry in the development of such residual fields in both the case and the core. To verify the results, the final fields were corroborated by the X-ray diffraction procedure.