The use of allogeneic haematopoietic stem cell transplantation (Allo-HSCT) is a standard treatment option for many patients with haematological malignancies. Historically, patients requiring intensive care unit (ICU) admission for transplant-related toxicities have fared extremely poorly, with high ICU mortality rates. Little is known about the impact of reduced intensity Allo-HSCT conditioning regimens in older patients on the ICU and subsequent long-term outcomes. A retrospective analysis of data collected from 164 consecutive Allo-HSCT recipients admitted to ICU for a total of 213 admissions, at a single centre over an 11·5-year study period was performed. Follow-up was recorded until 31 March 2011. Autologous HSCT recipients were excluded. In this study we report favourable ICU survival following Allo-HSCT and, for the first time, demonstrate significantly better survival for patients who underwent Allo-HSCT with reduced intensity conditioning compared to those treated with myeloablative conditioning regimens. In addition, we identified the need for ventilation (invasive or non-invasive) as an independently significant adverse factor affecting short-term ICU outcome. For patients surviving ICU admission, subsequent long-term overall survival was excellent; 61% and 51% at 1 and 5 years, respectively. Reduced intensity Allo-HSCT patients admitted to ICU with critical illness have improved survival compared to myeloablative Allo-HSCT recipients.

Purpose To determine whether inhibition of mechanistic target of rapamycin (mTOR) kinase-mediated signaling represents a valid therapeutic approach for chronic lymphocytic leukemia (CLL). Experimental Design Stratification of mTOR activity was carried out in primary CLL patient samples and an aggressive CLL-like mouse model. The potency of dual mTOR inhibitor AZD8055 to induce apoptosis in primary CLL cells was assessed in the presence/absence of B cell receptor (BCR) ligation. Furthermore, we addressed the molecular and functional impact of dual mTOR inhibition in combination with BTK inhibitor ibrutinib. Results Differential regulation of basal mTORC1 activity was observed in poor prognostic CLL samples, with elevated p4EBP1T37/46 and decreased p70S6 kinase activity, suggesting that dual mTORC1/2 inhibitors may exhibit improved response in poor prognostic CLL compared with rapalogs. AZD8055 treatment of primary CLL cells significantly reduced CLL survival in vitro compared with rapamycin, preferentially targeting poor prognostic subsets and overcoming BCR-mediated survival advantages. Furthermore, AZD8055, and clinical analog AZD2014, significantly reduced CLL tumor load in mice. AKT substrate FOXO1, while overexpressed in CLL cells of poor prognostic patients in LN biopsies, peripheral CLL cells, and mouse-derived CLL-like cells, appeared to be inactive. AZD8055 treatment partially reversed FOXO1 inactivation downstream of BCR crosslinking, significantly inhibiting FOXO1T24 phosphorylation in an mTORC2-AKT-dependent manner, to promote FOXO1 nuclear localization, activity and FOXO1-mediated gene regulation. FOXO1 activity was further significantly enhanced on combining AZD8055 with ibrutinib. Conclusions Our studies demonstrate that dual mTOR inhibitors show promise as future CLL therapies, particularly in combination with ibrutinib.

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Mechanistic target for rapamycin (mTOR) is a serine/threonine protein kinase that forms two distinct complexes mTORC1 and mTORC2, integrating mitogen and nutrient signals to regulate cell survival and proliferation; processes which are commonly deregulated in human cancers. mTORC1 and mTORC2 have divergent molecular associations and cellular functions: mTORC1 regulates in mRNA translation and protein synthesis, while mTORC2 is involved in the regulation of cellular survival and metabolism. Through AKT phosphorylation/activation, mTORC2 has also been reported to regulate cell migration. Recent attention has focused on the aberrant activation of the PI3K/mTOR pathway in B cell malignancies and there is growing evidence for its involvement in disease pathogenesis, due to its location downstream of other established novel drug targets that intercept B cell receptor (BCR) signals. Shared pharmacological features of BCR signal inhibitors include a striking "lymphocyte redistribution" effect whereby patients experience a sharp increase in lymphocyte count on initiation of therapy followed by a steady decline. Chronic lymphocytic leukemia (CLL) serves as a paradigm for migration studies as lymphocytes are among the most widely travelled cells in the body, a product of their role in immunological surveillance. The subversion of normal lymphocyte movement in CLL is being elucidated; this review aims to describe the migration impairment which occurs as part of the wider context of cancer cell migration defects, with a focus on the role of mTOR in mediating migration effects downstream of BCR ligation and other microenvironmental signals.