Hepatocellular carcinoma (HCC), the most common form of primary liver cancer, typically develops on the background of chronic liver disease and is an aggressive disease with dismal prognosis. Studies ...using next-generation sequencing of multiple regions of the same tumour nodule suggest different patterns of HCC evolution and confirm the high molecular heterogeneity in a subset of patients. Different hypotheses have been proposed to explain tumour evolution, including clonal selection or neutral and punctuated acquisition of genetic alterations. In parallel, data indicate a fundamental contribution of nonmalignant cells of the tumour microenvironment to cancer clonal evolution. Delineating these dynamics is crucial to improve the treatment of patients with HCC, and particularly to help understand how HCC evolution drives resistance to systemic therapies. A number of new minimally invasive techniques, such as liquid biopsies, could help track cancer evolution in HCC. These tools might improve our understanding of how systemic therapies affect tumour clonal composition and could facilitate implementation of real-time molecular monitoring of patients with HCC.
In the nematode C. elegans, RNAi silencing signals are efficiently taken up from the environment and transported between cells and tissues 1–3. Previous studies implicating endosomal proteins in ...systemic RNAi lack conclusive evidence 4, 5. Here, we report the identification and characterization of SID-5, a C. elegans endosome-associated protein that is required for efficient systemic RNAi in response to both ingested and expressed double-stranded RNA (dsRNA). SID-5 is detected in cytoplasmic foci that partially colocalize with GFP fusions of late endosomal proteins RAB-7 and LMP-1. Furthermore, knockdown of various endosomal proteins similarly relocalizes both SID-5 and LMP-1::GFP. Consistent with a non-cell-autonomous function, intestine-specific SID-5 expression restored body wall muscle (bwm) target gene silencing in response to ingested dsRNA. Finally, we show that sid-5 is required for the previously described sid-1-independent transport of ingested RNAi triggers across the intestine 6. Together, these data demonstrate that an endosome-associated protein, SID-5, promotes the transport of RNAi silencing signals between cells. Furthermore, SID-5 acts differently than the previously described SID-1, SID-2, and SID-3 proteins 3, 6–8, thus expanding the systemic RNAi pathway.
► sid-5 mutants are defective in systemic RNAi ► The SID-5 protein colocalizes with late endosomal proteins RAB-7 and LMP-1 ► Intestinal SID-5 overexpression restores silencing in muscle cells in a sid-5 mutant ► sid-5 is required for sid-1-independent intestinal transport of silencing signals
Little is known about the mutational landscape of advanced hepatocellular carcinoma (HCC), and predictive biomarkers of response to systemic therapies are lacking. We aimed to describe the mutational ...landscape of advanced HCC and to identify predictors of primary resistance to systemic therapies using circulating tumor DNA (ctDNA). We prospectively enrolled 121 patients between October 2015 and January 2019. We performed targeted ultra-deep sequencing of 25 genes and Digital Droplet PCR of TERT promoter, including sequential samples throughout treatment. Primary endpoint was progression-free survival (PFS) stratified by mutation profiles in ctDNA. Secondary endpoints were overall survival and objective response rate. The most frequent mutations in ctDNA of advanced HCC were TERT promoter (51%), TP53 (32%), CTNNB1 (17%), PTEN (8%), AXIN1, ARID2, KMT2D, and TSC2 (each 6%). TP53 and CTNNB1 mutations were mutually exclusive. Patients with mutations in the PI3K/MTOR pathway had significantly shorter PFS than those without these mutations after tyrosine kinase inhibitors (2.1 vs 3.7 months, p < 0.001), but not after immune checkpoint inhibition (CPI). WNT pathway mutations were not associated with PFS, overall survival, or objective response after CPI. Serial profiling of ctDNA in a subset correlated with treatment response. Mutation profiling of ctDNA in advanced HCC shows similar mutation frequencies for known HCC drivers compared to early stages and identifies predictive biomarkers of response to systemic therapies.
Over the last decade, precision medicine and immunotherapeutic approaches have become increasingly popular in oncology. Early clinical trials reported promising results, but response rates in phase ...III clinical trials have been suboptimal. Knowledge gained from subsequent translational studies indicates the importance of targeting the tumour microenvironment to overcome resistance to immunotherapy. In this era of precision medicine, it is crucial to consider inter- as well as intratumoural heterogeneity. Single-cell analysis is a cutting-edge technology that enables us to better define the tumour cell community and to identify potential targets for immunotherapy or combination treatments. This review focuses on single-cell analysis in the context of immunotherapy in liver cancer, including the rationale behind studying hepatocellular carcinoma biology at a single-cell level. Single-cell technologies have the potential to revolutionise our understanding of resistance mechanisms and to guide drug discovery efforts, leading to further advances in personalised medicine.
Cellular components of solid tumors including DNA are released into the bloodstream, but data on circulating-free DNA (cfDNA) in hepatocellular carcinoma (HCC) are still scarce. This study aimed at ...analyzing mutations in cfDNA and their correlation with tissue mutations in patients with HCC. We included 8 HCC patients treated with surgical resection for whom we collected paired tissue and plasma/serum samples. We analyzed 45 specimens, including multiregional tumor tissue sampling (n = 24), peripheral blood mononuclear cells (PMBC, n = 8), plasma (n = 8) and serum (n = 5). Ultra-deep sequencing (5500× coverage) of all exons was performed in a targeted panel of 58 genes, including frequent HCC driver genes and druggable mutations. Mutations detected in plasma included known HCC oncogenes and tumor suppressors (e.g., TERT promoter, TP53, and NTRK3) as well as a candidate druggable mutation (JAK1). This approach increased the detection rates previously reported for mutations in plasma of HCC patients. A thorough characterization of cis mutations found in plasma confirmed their tumoral origin, which provides definitive evidence of the release of HCC-derived DNA fragments into the bloodstream. This study demonstrates that ultra-deep sequencing of cfDNA is feasible and can confidently detect somatic mutations found in tissue; these data reinforce the role of plasma DNA as a promising minimally invasive tool to interrogate HCC genetics.
Commensal bacteria are believed to have important roles in human health. The mechanisms by which they affect mammalian physiology remain poorly understood, but bacterial metabolites are likely to be ...key components of host interactions. Here we use bioinformatics and synthetic biology to mine the human microbiota for N-acyl amides that interact with G-protein-coupled receptors (GPCRs). We found that N-acyl amide synthase genes are enriched in gastrointestinal bacteria and the lipids that they encode interact with GPCRs that regulate gastrointestinal tract physiology. Mouse and cell-based models demonstrate that commensal GPR119 agonists regulate metabolic hormones and glucose homeostasis as efficiently as human ligands, although future studies are needed to define their potential physiological role in humans. Our results suggest that chemical mimicry of eukaryotic signalling molecules may be common among commensal bacteria and that manipulation of microbiota genes encoding metabolites that elicit host cellular responses represents a possible small-molecule therapeutic modality (microbiome-biosynthetic gene therapy).
Ortiz Jr, RO, Sinclair Elder, AJ, Elder, CL, and Dawes, JJ. A systematic review on the effectiveness of active recovery interventions on athletic performance of professional-, collegiate-, and ...competitive-level adult athletes. J Strength Cond Res 33(8): 2275-2287, 2019-Active recovery (AR) is a popular approach to enhancing athlete recovery from participation through physical action, and it has a perceived benefit in the recovery of athletes' enhancement of postexertional physiological status; however, it is unclear whether these recovery techniques enhance athletic performance. The purpose of this systematic review was to examine the effects of AR interventions conducted postexertion on athletic performance among professional, collegiate, and competitive adult athletes. Articles were collected via 4 online databases restricted to publication in English between 1998 and 2014. After the evaluation of overlap among the databases and abstract review, 150 potential eligible studies remained. Twenty-six articles involving 471 subjects remained after full analysis. The primary exclusion factor was absence of AR types of interest or measures of performance. The review resulted in a wide variety of findings indicating the vagueness in AR approach and outcome measures, making it difficult to draw specific conclusions. The review demonstrated that AR interventions lasting 6-10 minutes revealed consistently positive effects on performance. The appropriate intensity level of AR sessions was inconclusive in the literature; however, blood lactate clearance rate as a recovery marker appeared unreliable. The review suggests that there are positive psychological outcomes from AR sessions, a need to determine if AR should be individualized in its application, and weak evidence regarding the efficacy of postexercise AR, particularly relating to performance. Future research is needed for reliable and accurate markers for fatigue, physiological recovery, performance, and markers of intensity and duration for AR interventions.
Each additional copy of the apolipoprotein E4 (APOE4) allele is associated with a higher risk of Alzheimer's dementia, while the APOE2 allele is associated with a lower risk of Alzheimer's dementia, ...it is not yet known whether APOE2 homozygotes have a particularly low risk. We generated Alzheimer's dementia odds ratios and other findings in more than 5,000 clinically characterized and neuropathologically characterized Alzheimer's dementia cases and controls. APOE2/2 was associated with a low Alzheimer's dementia odds ratios compared to APOE2/3 and 3/3, and an exceptionally low odds ratio compared to APOE4/4, and the impact of APOE2 and APOE4 gene dose was significantly greater in the neuropathologically confirmed group than in more than 24,000 neuropathologically unconfirmed cases and controls. Finding and targeting the factors by which APOE and its variants influence Alzheimer's disease could have a major impact on the understanding, treatment and prevention of the disease.
Microglia are myeloid cells of the CNS that participate both in normal CNS function and in disease. We investigated the molecular signature of microglia and identified 239 genes and 8 microRNAs that ...were uniquely or highly expressed in microglia versus myeloid and other immune cells. Of the 239 genes, 106 were enriched in microglia as compared with astrocytes, oligodendrocytes and neurons. This microglia signature was not observed in microglial lines or in monocytes recruited to the CNS, and was also observed in human microglia. We found that TGF-β was required for the in vitro development of microglia that express the microglial molecular signature characteristic of adult microglia and that microglia were absent in the CNS of TGF-β1-deficient mice. Our results identify a unique microglial signature that is dependent on TGF-β signaling and provide insights into microglial biology and the possibility of targeting microglia for the treatment of CNS disease.
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