Andrew J. Innes

mTOR regulates MAPKAPK2 translation to control the senescence-associated secretory phenotype

Senescent cells secrete a combination of factors collectively known as the senescence-associated secretory phenotype (SASP). The SASP reinforces senescence and activates an immune surveillance response, but it can also show pro-tumorigenic properties and contribute to age-related pathologies. In a drug screen to find new SASP regulators, we uncovered the mTOR inhibitor rapamycin as a potent SASP suppressor. Here we report a mechanism by which mTOR controls the SASP by differentially regulating the translation of the MK2 (also known as MAPKAPK2) kinase through 4EBP1. In turn, MAPKAPK2 phosphorylates the RNA-binding protein ZFP36L1 during senescence, inhibiting its ability to degrade the transcripts of numerous SASP components. Consequently, mTOR inhibition or constitutive activation of ZFP36L1 impairs the non-cell-autonomous effects of senescent cells in both tumour-suppressive and tumour-promoting contexts. Altogether, our results place regulation of the SASP as a key mechanism by which mTOR could influence cancer, age-related diseases and immune responses.

Dark chocolate inhibits platelet aggregation in healthy volunteers

Cardiovascular disease is a leading cause of death in the UK. The flavonoids found in cocoa may produce a cardio-protective role for chocolate with a high cocoa content. Thirty healthy volunteers were randomised to receive 100 g of white, milk or dark chocolate, and assessments of platelet function were undertaken on venous blood samples before and after chocolate consumption. White and milk chocolate had no significant effect on platelets. However dark chocolate inhibited collagen-induced platelet aggregation in platelet rich plasma. In the future dark chocolate may have a role in prevention of cardiovascular and thromboembolic diseases.

Allogeneic transplantation for CML in the TKI era: striking the right balance.

The management of chronic myeloid leukaemia (CML) has changed extensively over the past 15 years. Prior to the development of targeted therapies and in the absence of allogeneic haematopoetic stem-cell transplantation (HSCT), the median survival was 5–7 years. HSCT was quickly established as the standard of care for eligible patients through the 1980s and 1990s, when considerable advances were made in the optimization of conditioning regimens and supportive care. Exploiting a deeper understanding of the molecular basis of CML, the development of tyrosine kinase inhibitors (TKIs) in the late 1990s revolutionized the management of the disease. TKIs offer the prospect of long-term disease control with a simple oral therapy, and are the first-line treatment in the 21st century. The majority of patients treated with TKIs achieve excellent responses with sustained treatment, and some even continue to have undetectable or exceptionally low level disease upon TKI withdrawal; however, for an almost equal number of patients, an adequate response cannot be achieved with any of the currently available TKIs. For those patients who fail to respond adequately to TKIs, HSCT offers the best prospect of long-term survival.

Chronic myeloid leukemia-transplantation in the tyrosine kinase era.

Allogeneic hematopoietic stem cell transplantation (HSCT) revolutionized the outlook for many patients with chronic myeloid leukemia (CML) in the 1980s. The introduction of the tyrosine kinase inhibitors (TKIs) nearly 15 years ago displaced HSCT as the first-line treatment for most CML patients. However, in the twenty-first century HSCT remains a viable treatment option for many patients with CML. This review focuses on the role of HSCT for CML in the TKI era, paying particular attention to patient selection and transplant outcome.

BKV-specific T cells in the treatment of severe refractory haemorrhagic cystitis after HLA-haploidentical haematopoietic cell transplantation

Haemorrhagic cystitis caused by BK virus (BKV) is a known complication of allogeneic haematopoietic cell transplantation (HCT) and is relatively common following HLA‐haploidentical transplantation. Adoptive immunotransfer of virus‐specific T cells from the donor is a promising therapeutic approach, although production of these cells is challenging, particularly when dealing with low‐frequency T cells such as BKV‐specific T cells.

Escalating-dose HLA-mismatched DLI is safe for the treatment of leukaemia relapse following alemtuzumab-based myeloablative allo-SCT

Although the feasibility of using HLA-mismatched unrelated donors as an alternate graft source for haematopoietic SCT (HSCT) has been shown, little is known about the safety of HLA-mismatched DLI for the treatment of relapse. We examined the outcome of 58 consecutive leukaemia patients who received escalating-dose DLI for treatment of relapse after alemtuzumab-conditioned myeloablative unrelated donor HSCT at our institution. High-resolution HLA typing on stored DNA samples revealed mismatches in 28/58 patients who were considered HLA-matched at the time of transplantation. Following DLI from HLA-matched (10/10) (n=30) or -mismatched (7-9/10) (n=28) unrelated donors, we found no significant difference in the incidence of acute GVHD (17.2% versus 23.1%, P=0.59), probability of remission at 3 years (62.1% versus 63.9%, P=0.89) or 5-year OS (89.8% versus 77.7%, P=0.22). We conclude that escalating-dose DLI can be safely given to HLA-mismatched recipients following T-depleted myeloablative HSCT.

Faecal microbiota transplant: a novel biological approach to extensively drug-resistant organism-related non-relapse mortality.

Faecal microbiota transplant: a novel biological approach to extensively drug-resistant organism-related non-relapse mortality

C-reactive protein prior to myeloablative allogeneic haematopoietic cell transplantation identifies patients at risk of early- and long-term mortality

Patient selection for allogeneic haematopoietic cell transplantation (HCT) is complex and outcome can be predicted by the HCT comorbidity index (HCT-CI) (Sorror et al, 2005) or the European Group for Blood and Marrow Transplantation (EBMT) score (Gratwohl et al, 1998; Gratwohl, 2012). HCTCI accounts for patient factors such as proven or suspected recipient infection, and the EBMT score includes disease and treatment factors. C-reactive protein (CRP) level, performed pre-myeloablative conditioning (MAC) and reduced intensity conditioning (RIC), is an inexpensive and internationally available biomarker that may be associated with clinical outcomes post-allogeneic HCT (Artz et al, 2008; Pavlu et al, 2010; Aki et al, 2012). This study addresses whether CRP elevation above a normal reference range (>9 mg/l) prior to MAC is additive to information provided by the HCT-CI and component factors of the EMBT score, in identifying patients with inferior early (non-relapse mortality [NRM] at 100 days) or late survival at 5 years, compared to patients with a normal CRP (0–9 mg/l). A retrospective cohort study using prospectively acquired routine clinical data was undertaken. Primary endpoints were: survival calculated from the day of HCT until death from any cause; and NRM, defined as any cause of death not related to relapse that occurred within 100 days post-HCT. The secondary outcomes were disease relapse, acute and chronic graft-versus-host disease (GvHD). Further details are presented in the online supplement. Two hundred and sixty-four adults were identified that received MAC prior to allogeneic HCT over the 18-year study period. Eleven patients with incomplete CRP data were excluded (online supplement and Figure S1). The median age of the 253 evaluable patients was 37 years (range 17–63). Indications for transplant are outlined in Table S1. The primary outcome of NRM at 100 days was 19 8% [95% confidence interval (CI) 16–25] and survival at 5 years was 41 9% (95% CI 35–47), with a median follow-up of 60 6 months (range 3–187) for patients alive at last contact. Validation of the HCT-CI and EBMT score, and univariate analyses with CRP are presented in the online supplement (Tables S2 and S3). C-reactive protein was associated with increased NRM independent of the HCT-CI and EBMT score components. In a

Unexpected pancytopenia following treatment of acute lymphoblastic leukemia.

A 55-year-old woman presented with lethargy and spontaneous bruising. A full blood count showed: white cell count (WBC) 1.6 x 10/l, hemoglobin concentration (Hb) 7.8 g/dl, platelet count 35 x 10/l and neutrophil count 0.1 x 10/l. There were blast cells in the peripheral blood. A diagnosis of B-lineage acute lymphoblastic leukemia (ALL) was made, the immunophenotype being that of common ALL. Cytogenetic analysis was normal. The patient entered complete remission with induction chemotherapy according to the UKALL XII protocol. She received consolidation chemotherapy and cranial irradiation followed by maintenance chemotherapy (mercaptopurine 50 mg daily, methotrexate 15 mg weekly and vincristine 2 mg 3-monthly) plus intrathecal cytarabine 3-monthly. Twenty six months after presentation while still on maintenance therapy the patient became pancytopenic; WBC 0.9 x 10/l, Hb 8 g/dl, platelet count 20 x 10/l and neutrophil count 0.6 x 10/l. A bone marrow aspirate showed markedly megaloblastic erythropoiesis with giant metamyelocytes and giant band forms. However there were also 8% blast cells (Image, arrows), which immunophenotypically typed as myeloid. Cytogenetic analysis showed 46,XX,t(6;9)(p23;q34)[19]/46,XX[1]. A diagnosis of therapy-related myelodysplastic syndrome (t-MDS) was made and the weekly methotrexate was stopped. Over the next two and a half months there was progression to 88% bone marrow blasts, accompanied by cytogenetic evolution to 46,XX,t(6;9)(p23;q34)[2]/48,idem,113,115[9]. At this stage there was normoblastic erythropoiesis with no giant metamyelocytes. The patient proved to be refractory to chemotherapy. Our initial suspicion on discovering markedly megaloblastic erythropoiesis was that the pancytopenia was the result of methotrexate toxicity. However the presence of increased blast cells indicated other possibilities, either t-MDS or early relapse of ALL. Acute myeloid leukemia (AML) with t(6;9)(p23;q34) resulting in the DEK-NUP214 fusion gene is a recognised form of t-AML. Megaloblastosis can be a feature of AML but in this patient, since erythropoiesis became normoblastic on methotrexate withdrawal, it was indeed a drug-induced megaloblastosis. The pancytopenia, however, was the result of an emerging t-AML, probably resulting from etoposide or daunorubicin of which she had received total doses of 340 mg/m and 2.7 g respectively. Alkylating agents have also been followed by t-AML with t(6;9) but cyclophosphamide is not a potent leukemogen.

Biomedical Research in Aging

Biomedical research has been instrumental in identifying key molecular and cellular changes that occur throughout the aging process, also known as the Hallmarks of Aging. Notably, these are shared between humans and several other species that have served as models for the study of aging in the laboratory. In this chapter, we discuss current knowledge regarding the significance of hallmarks such as: decay of stem cell function, acquisition of genomic instability, DNA damage, telomere attrition, deregulated nutrient sensing, chronic inflammation and cellular senescence. We further describe current methodological issues, experimental techniques and best practices for the study of each hallmark across different in vivo and in vitro systems, while also pointing at their limitations. Finally, we provide future perspectives for the improvement of experimental designs in biomedical research of aging.