The lethal response to Cdk1 inhibition depends on sister chromatid alignment errors generated by KIF4 and isoform 1 of PRC1

Cyclin-dependent kinase 1 (Cdk1) is absolutely essential for cell division. Complete ablation of Cdk1 precludes the entry of G2 phase cells into mitosis, and is early embryonic lethal in mice. Dampening Cdk1 activation, by reducing gene expression or upon treatment with cell-permeable Cdk1 inhibitors, is also detrimental for proliferating cells, but has been associated with defects in mitotic progression, and the formation of aneuploid daughter cells. Here, we used a large-scale RNAi screen to identify the human genes that critically determine the cellular toxicity of Cdk1 inhibition. We show that Cdk1 inhibition leads to fatal sister chromatid alignment errors and mitotic arrest in the spindle checkpoint. These problems start early in mitosis and are alleviated by depletion of isoform 1 of PRC1 (PRC1-1), by gene ablation of its binding partner KIF4, or by abrogation of KIF4 motor activity. Our results show that, normally, Cdk1 activity must rise above the level required for mitotic entry. This prevents KIF4-dependent PRC1-1 translocation to astral microtubule tips and safeguards proper chromosome congression. We conclude that cell death in response to Cdk1 inhibitors directly relates to chromosome alignment defects generated by insufficient repression of PRC1-1 and KIF4 during prometaphase

High speed synchrotron X-ray imaging studies of the ultrasound shockwave and enhanced flow during metal solidification processes

The highly dynamic behaviour of ultrasonic bubble implosion in liquid metal, the multiphase liquid metal flow containing bubbles and particles, and the interaction between ultrasonic waves and semisolid phases during solidification of metal were studied in situ using the complementary ultrafast and high speed synchrotron X-ray imaging facilities housed respectively at the Advanced Photon Source, Argonne National Laboratory, US, and Diamond Light Source, UK. Real-time ultrafast X-ray imaging of 135,780 frames per second (fps) revealed that ultrasonic bubble implosion in a liquid Bi-8 wt. %Zn alloy can occur in a single wave period (30 kHz), and the effective region affected by the shockwave at implosion was 3.5 times the original bubble diameter. Furthermore, ultrasound bubbles in liquid metal move faster than the primary particles, and the velocity of bubbles is 70 ~ 100% higher than that of the primary particles present in the same locations close to the sonotrode. Ultrasound waves can very effectively create a strong swirling flow in a semisolid melt in less than one second. The energetic flow can detach solid particles from the liquid-solid interface and redistribute them back into the bulk liquid very effectively

Intrinsic resistance to PIM kinase inhibition in AML through p38α-mediated feedback activation of mTOR signaling

Although conventional therapies for acute myeloid leukemia (AML) and diffuse large B-cell lymphoma (DLBCL) are effective in inducing remission, many patients relapse upon treatment. Hence, there is an urgent need for novel therapies. PIM kinases are often overexpressed in AML and DLBCL and are therefore an attractive therapeutic target. However, in vitro experiments have demonstrated that intrinsic resistance to PIM inhibition is common. It is therefore likely that only a minority of patients will benefit from single agent PIM inhibitor treatment. In this study, we performed an shRNA-based genetic screen to identify kinases whose suppression is synergistic with PIM inhibition. Here, we report that suppression of p38α (MAPK14) is synthetic lethal with the PIM kinase inhibitor AZD1208. PIM inhibition elevates reactive oxygen species (ROS) levels, which subsequently activates p38α and downstream AKT/mTOR signaling. We found that p38α inhibitors sensitize hematological tumor cell lines to AZD1208 treatment in vitro and in vivo. These results were validated in ex vivo patient-derived AML cells. Our findings provide mechanistic and translational evidence supporting the rationale to test a combination of p38α and PIM inhibitors in clinical trials for AML and DLBCL

Efficacy of the PanCareFollowUp eHealth Lifestyle Intervention for Survivors of Childhood, Adolescent and Young Adult Cancer

Purpose: A healthy lifestyle may prevent or mitigate late effects in childhood, adolescent and young adult (CAYA) cancer survivors. To support survivors in adopting healthier behaviours, the PanCareFollowUp (PCFU) Lifestyle intervention was developed, encompassing 4 months of online lifestyle coaching aimed at achieving a personal lifestyle goal. The aims of this study were to (1) determine the efficacy of this intervention on lifestyle outcomes over time and (2) identify predictors for goal achievement. Patients and Methods: Fifty-eight survivors were enrolled. Outcomes were assessed at baseline (T0), after 4 months of coaching (T1) and after 4 months of follow-up (T2). The primary outcome included the percentage of survivors successful in achieving and sustaining their goal, whereas secondary outcomes included differences in body mass index (BMI), diet and physical activity. To evaluate the adjusted, longitudinal effects on secondary outcomes, linear mixed models were estimated. Predictors for goal achievement were identified through logistic regression analysis. Results: At T1 and T2, 68% and 76% of goals were achieved or sustained, respectively. Mean differences between T2 and T0 showed significant improvements in BMI (−0.5 kg/m2), diet (−0.6 points) and physical activity (+7.7 h/week). Estimation of multivariable models also showed positive effects. Participants with a lower BMI and fewer depressive feelings at baseline were more likely to achieve and/or sustain their goals at T2. Conclusion: Findings suggest that the PCFU Lifestyle intervention supports survivors in making lifestyle changes. Results can be used to inform a subsequent randomised intervention study and integrate lifestyle coaching into care. Trial Registration: International Clinical Trial Registry Platform (ICTRP) number: NL8932 (ICTRP Search Portal [who. int]). Registered on 29 September 2020