Bayesian consensus clustering for multivariate longitudinal data

In clinical and epidemiological studies, there is a growing interest in studying the heterogeneity among patients based on longitudinal characteristics to identify subtypes of the study population. Compared to clustering a single longitudinal marker, simultaneously clustering multiple longitudinal markers allow additional information to be incorporated into the clustering process, which reveals co-existing longitudinal patterns and generates deeper biological insight. In the current study, we propose a Bayesian consensus clustering (BCC) model for multivariate longitudinal data. Instead of arriving at a single overall clustering, the proposed model allows each marker to follow marker-specific local clustering and these local clusterings are aggregated to find a global (consensus) clustering. To estimate the posterior distribution of model parameters, a Gibbs sampling algorithm is proposed. We apply our proposed model to the primary biliary cirrhosis study to identify patient subtypes that may be associated with their prognosis. We also perform simulation studies to compare the clustering performance between the proposed model and existing models under several scenarios. The results demonstrate that the proposed BCC model serves as a useful tool for clustering multivariate longitudinal data.     

Cryo-thermal therapy inducing MI macrophage polarization created CXCL10 and IL-6-rich pro-inflammatory environment for CD4+ T cell-mediated anti-tumor immunity

Purpose: We previously developed a novel cryo-thermal therapy to treat malignant mammary carcinoma and melanoma in a mouse model; long-term survival and CD4⁺ T cell orchestrating anti-tumor immune memory response were achieved. Moreover, cryo-thermal-induced CD4⁺ T cell differentiation into Th1 and CD4⁺CTL sub-lineages, in which M1 macrophage polarization played a direct, important role. In particular, cryo-thermal therapy triggered M1 macrophage polarization with up-regulated expression of C–X–C motif ligand 10 (CXCL10) and Interleukin 6 (IL-6). But whether CXCL10 and IL-6 contribute to CD4⁺ T cell-mediated anti-tumor immunity remains unclear. In this study, the role of cryo-thermal-induced CXCL10 and IL-6 in anti-tumor immunity was determined.

Methods: The level of CXCL10 and IL-6 in spleen and serum was determined by RT-PCR and ELISA on day 14 after cryo-thermal therapy. Splenic dendritic cells (DCs) and macrophages were isolated from cryo-thermal-treated mice on day 5 and 14, and the level of CXCL10 and IL-6 in macrophages and DCs was determined by ELISA. The transwell migration assay was performed to study immune cell migration. In vivo neutralization of CXCL10 or IL-6 was performed to investigate the phenotypic changes of immune cells.

Results: Cryo-thermal therapy induced M1 macrophage polarization with up-regulation of CXCL10 and IL-6 expression in spleen. CXCL10 and IL-6 promoted DCs migration and maturation, and subsequently promoted CD4⁺ T cell migration and differentiation into Th1 and CD4⁺ CTL, moreover, reduced myeloid-derived suppressor cells (MDSCs) accumulation.

Conclusions: Cryo-thermal-induced CXCL10 and IL-6 created acute inflammatory environment to initiate a systemically cascading innate and adaptive anti-tumor immunity, which was more permissive for tumor eradication.     

A novel prognostic scoring model for newly diagnosed FLT3-ITD-positive acute myeloid leukemia

FMS-like tyrosine kinase 3-internal tandem duplication (FLT3-ITD) is one of the most common somatic mutations in acute myeloid leukemia (AML). However, the molecular structure characteristics and widely accepted prognostic factors for FLT3-ITD are still not well described. This study aimed to retrospectively examine 81 patients with FLT3-ITD-positive AML diagnosed and treated at the First Affiliated Hospital of Zhejiang University from December 2013 to March 2018 using the next-generation sequencing 185-gene platform. High variant allele frequency (VAF) [> 0.48, P = 0.0089 for overall survival (OS), P = 0.13 for relapse-free survival (RFS)], multiple ITDs (> 1 ITDs, P = 0.011 for OS, P = 0.033 for RFS) and longer insertion length (> 69 bp, P = 0.14 for OS, P = 0.0078 for RFS) predicted poor survival. The study further proposed an easily applicable scoring model for OS using the Least Absolute Shrinkage and Selector Operation (LASSO) Cox regression model. Also, an independent cohort of 30 patients was used for external model validation. The mode was expressed as follows: 0.659 × FLT3-ITD VAF + 0.375 × FLT3-ITD number + 0.807 × Age + 0.688 × DNMT3A + 1.939 × U2AF1 (FLT3-ITD VAF > 0.48 scored 1; FLT3-ITD number scored 1 if carried 1 ITD, 2 if carried ≥ 2 ITDs; age > 44 years scored 1, the presence of DNMT3A or U2AF1 scored 1; 0 for other conditions). It categorized patients into low-risk (L-R, score < 1, n = 20) and high-risk (H-R, score ≥ 1, n = 61) groups based on the risk score with a significant difference in survival (3-year OS, P < 0.0001; 3-year RFS, P = 0.0005). A prognostic nomogram that integrated these five factors was developed with a concordance index calculation [OS: 0.68, 95% CI (0.64-0.72)].     

未来提高胰腺癌临床诊治效果的十大方向

胰腺癌是恶性程度极高的消化系统肿瘤。近10年来, 由于治疗理念的更新和有效治疗方案的普及, 其治疗效果有所提高。然而, 胰腺癌总体疗效仍不尽如人意, 患者5年生存率仍仅为10%左右。如何进一步提高胰腺癌诊治水平, 是未来肿瘤学研究和临床实践的头等大事。作者团队基于既往临床和科研经验, 针对胰腺癌早期预防、早诊早治、分子分型、精准治疗、新药开发、方案联合、手术技术和策略改变、模型建立和数据库开发、传统中医药的创新和治疗理念的突破等, 提出十大热点和未来方向供大家参考。期待未来十年中, 胰腺癌诊治研究有突破性进展, 真正做到"可防可控"。     

Why considering sexual differences is necessary when studying encephalopathy of prematurity through rodent models

Preterm birth is a high‐risk factor for the development of gray and white matter abnormalities, referred to as “encephalopathy of prematurity,” that may lead to life‐long motor, cognitive, and behavioral impairments. The prevalence and clinical outcomes of encephalopathy of prematurity differ between sexes, and elucidating the underlying biological basis has become a high‐priority challenge. Human studies are often limited to assessment of brain region volumes by MRI, which does not provide much information about the underlying mechanisms of lesions related to very preterm birth. However, models using KO mice or pharmacological manipulations in rodents allow relevant observations to help clarify the mechanisms of injury sustaining sex‐differential vulnerability. This review focuses on data obtained from mice aged P1–P5 or rats aged P3 when submitted to cerebral damage such as hypoxia‐ischemia, as their brain lesions share similarities with lesion patterns occurring in very preterm human brain, before 32 gestational weeks. We first report data on the mechanisms underlying the development of sexual brain dimorphism in rodent, focusing on the hippocampus. In the second part, we describe sex specificities of rodent models of encephalopathy of prematurity (RMEP), focusing on mechanisms underlying differences in hippocampal vulnerability. Finally, we discuss the relevance of these RMEP. Together, this review highlights the need to systematically search for potential effects of sex when studying the mechanisms underlying deficits in RMEP in order to design effective sex‐specific medical interventions in human preterms.