Extracellular Vesicles in Hepatobiliary Cancer Management

Cancer is a global health problem that will intensify in the upcoming years and decades. Hepatobiliary cancers, comprising hepatocellular carcinoma (HCC), cholangiocarcinoma (CCA) and gallbladder carcinoma (GbCA), are among the most fatal types of cancers, owing to their commonly late-stage discovery and resulting bad prognoses with 5-year survival rates of 5-20%. Patient survival could considerably be improved if hepatobiliary cancers, especially biliary cancers (CCA and GbCA), were discovered and treated at earlier stages. Hepatobiliary cancers are a very heterogeneous group of tumors with considerably diverse treatment regimen. However, especially the distinction of HCC and iCCA remains an extremely difficult challenge that requires an invasive tissue biopsy for definitive diagnosis. Nonetheless, the distinction is crucial for following treatment decisions to ensure best patient care and survival. To date, no reliable serum biomarker exists for completely accurate detection and differentiation of these cancers. Extracellular vesicles (EVs), as a type of liquid biopsy, might offer the opportunity to not only discover hepatobiliary cancers at an earlier stage but also to differentiate between these cancer entities in an uncomplicated and easily applicable manner. EVs are phospholipid bilayer-enclosed vesicles that are released by every cell type including tumor cells. According to their size and mode of biogenesis, they can be classified into endosome-derived small EVs (40-100 nm) and plasma membrane-budding large EVs (100-1000 nm). They reflect the intracellular and surface composition of their parental cells and their potential as biomarkers for diseases has been demonstrated in a wide variety of studies. Here, the capability of EVs as biomarkers for differential diagnosis of hepatobiliary cancers, especially between HCC and iCCA, is assessed, in order to optimize patient care. In contrast to most biomarker studies on EVs that either focus on only one subtype or on the entirety of all EVs without specifying their molecular characteristics, this study comprehensively evaluates both large and small EVs separately in terms of their differential diagnostic capacity for hepatobiliary cancers. In this regard, the surface markers EpCAM, CD133, gp38 and CD44v6, that are all associated with carcinogenesis or cancer progression, were observed to be differentially expressed on human HCC and CCA tumor cell lines. Likewise, possible parental cell populations for EVs with combinations of the aforementioned markers on their surface were identified and showed a distinct expression pattern in several mouse organs, including liver and gallbladder. Large EVs (lEVs) featuring the corresponding surface marker combinations were isolated from peripheral patient blood, including HCC, CCA, GbCA, colorectal carcinoma (CRC), non-small cell lung carcinoma (NSCLC) and cirrhosis patients as well as healthy individuals. Flow cytometric analysis revealed that all investigated lEV populations served as biomarkers for biliary cancer with AnnV+CD44v6+ lEVs showing the best diagnostic performance (AUC: 0.80, sensitivity: 84.0%, specificity: 63.3%, PPV: 85.1%, NPV: 61.3%) for detecting biliary cancers out of a pool of healthy individuals. Furthermore, AnnV+CD44v6+ lEVs also displayed the best diagnostic capability for distinguishing between HCC and iCCA patients (AUC: 0.83, sensitivity: 93.3%, specificity: 71.0%, PPV: 60.9%, NPV: 95.7%). Importantly, when combining AnnV+CD44v6+ lEVs with the serum tumor marker AFP, a perfect separation of HCC and CCA was achieved with sensitivity, specificity, PPV and NPV all reaching 100%. Similarly, evaluation of several small EV (sEV) subtypes, characterized by CD9, CD63 or CD81 expression on their surface, by ExoView® scanning revealed a good diagnostic separation of HCC and iCCA patients with CD63+CD133+ sEVs showing the best diagnostic capability (AUC: 0.89, sensitivity: 87.5%, specificity: 100%, PPV: 100%, NPV: 88.9%). Even though small EVs achieved a similar diagnostic power for separation of HCC and iCCA than large EVs alone, the addition of APF in a combinational approach did not result in any diagnostically relevant improvement in this case. All in all, lEV profiling, especially AnnV+CD44v6+ lEVs, was proven to represent a diagnostically powerful marker for biliary cancers as well as for the clinically challenging differential diagnosis of iCCA and HCC that could be of great aid in complementing currently performed diagnostic procedures. As a minimal-invasive liquid biopsy, lEV profiling offers an easily accessible and applicable tool that is low in cost and risk and at the same time highly sensitive and specific. These advantages highlight the enormous potential of lEV profiling to improve informed decision-making during the challenging management of hepatobiliary cancers, thus maximizing best patient care and overall patient survival

Préserver et promouvoir l’humain dans la vie socio-économique

Le fondement de cette recherche est double : il repose sur un constat et sur une volonté. Le constat, qui s’exprime avec une acceptation croissante dans le monde, est que l’évolution de l’économie globalisée, que l’on peut observer depuis la fin des années 1980, allant dans le sens d’une financiarisation en progression rapide de la vie sociale, n’est pas « soutenable » dans la durée car elle porte en elle les germes d’affaiblissement de valeurs humaines au profit de la toute-puissance de l’ar..

Developmental and tissue-specific expression of the Q5k gene

Expression of the Q5k gene was examined by northern blot analysis and polymerase chain reaction (PCR) in the AKR mouse and various cell lines, each of the H-2k haplotype. Our results show that Q5k mRNA is present during the whole postimplantational development of the AKR embryo/fetus (gestation day 6 to 15). In the juvenile mouse (week 2 to 4) transcription of the Q5k gene persisted in all organs examined. In contrast, in the adult animal expression of the Q5k gene was limited to the thymus and uterus of the pregnant mouse. Upon malignant transformation, the amount of Q5k-specific mRNA increased dramatically in thymus and could also be observed in the spleen of thymoma bearing animals. Expression of the Q5k gene was also detectable in several transformed mouse cell lines. Mitogen stimulation or treatment with cytokines induced Q5k expression in primary spleen cell cultures. A possible explanation for the tissue-restricted expression in the adult AKR mouse is discussed

Développement durable et gestion internationale : enjeux et perspectives d'avenir.

Développement durable et gestion internationale : enjeux et perspectives d'avenir. Texte d'introduction au numéro thématiqueCommerce international; Développement durable;

Different Sources of Allelic Variation Drove Repeated Color Pattern Divergence in Cichlid Fishes

The adaptive radiations of East African cichlid fish in the Great Lakes Victoria, Malawi, and Tanganyika are well known for their diversity and repeatedly evolved phenotypes. Convergent evolution of melanic horizontal stripes has been linked to a single locus harboring the gene agouti-related peptide 2 (agrp2). However, where and when the causal variants underlying this trait evolved and how they drove phenotypic divergence remained unknown. To test the alternative hypotheses of standing genetic variation versus de novo mutations (independently originating in each radiation), we searched for shared signals of genomic divergence at the agrp2 locus. Although we discovered similar signatures of differentiation at the locus level, the haplotypes associated with stripe patterns are surprisingly different. In Lake Malawi, the highest associated alleles are located within and close to the 5′ untranslated region of agrp2 and likely evolved through recent de novo mutations. In the younger Lake Victoria radiation, stripes are associated with two intronic regions overlapping with a previously reported cis-regulatory interval. The origin of these segregating haplotypes predates the Lake Victoria radiation because they are also found in more basal riverine and Lake Kivu species. This suggests that both segregating haplotypes were present as standing genetic variation at the onset of the Lake Victoria adaptive radiation with its more than 500 species and drove phenotypic divergence within the species flock. Therefore, both new (Lake Malawi) and ancient (Lake Victoria) allelic variation at the same locus fueled rapid and convergent phenotypic evolution.Peer reviewe

Of bars and stripes : A Malawi cichlid hybrid cross provides insights into genetic modularity and evolution of modifier loci underlying colour pattern diversification

Abstract Understanding the origins of phenotypic diversity among closely related species remains an important largely unsolved question in evolutionary biology. With over 800 species, Lake Malawi haplochromine cichlid fishes are a prominent example of extremely fast evolution of diversity including variation in coloration. Previously, a single major effect gene, agrp2 (asip2b), has been linked to evolutionary losses and gains of horizontal stripe patterns in cichlids, but it remains unknown what causes more fine-scale variation in the number and continuity of the stripes. Also, the genetic basis of the most common color pattern in African cichlids, vertical bars, and potential interactions between the two color patterns remain unknown. Based on a hybrid cross of the horizontally striped Lake Malawi cichlid Pseudotropheus cyaneorhabdos and the vertically barred species Chindongo demasoni we investigated the genetic basis of both color patterns. The distribution of phenotypes in the F2 generation of the cross indicates that horizontal stripes and vertical bars are independently inherited patterns that are caused by two sets of genetic modules. While horizontal stripes are largely controlled by few major effect loci, vertical bars are a highly polygenic trait. Horizontal stripes show substantial variation in the F2 generation that, interestingly, resemble naturally occurring phenotypes found in other Lake Malawi cichlid species. Quantitative trait loci (QTL) mapping of this cross reveals known (agrp2) and unknown loci underlying horizontal stripe patterns. These findings provide novel insights into the incremental fine-tuning of an adaptive trait that diversified through the evolution of additional modifier loci.Peer reviewe

The repeated evolution of stripe patterns is correlated with body morphology in the adaptive radiations of East African cichlid fishes

Abstract Color patterns are often linked to the behavioral and morphological characteristics of an animal, contributing to the effectiveness of such patterns as antipredatory strategies. Species-rich adaptive radiations, such as the freshwater fish family Cichlidae, provide an exciting opportunity to study trait correlations at a macroevolutionary scale. Cichlids are also well known for their diversity and repeated evolution of color patterns and body morphology. To study the evolutionary dynamics between color patterns and body morphology, we used an extensive dataset of 461 species. A phylogenetic supertree of these species shows that stripe patterns evolved ~70 times independently and were lost again ~30 times. Moreover, stripe patterns show strong signs of correlated evolution with body elongation, suggesting that the stripes? effectiveness as antipredatory strategy might differ depending on the body shape. Using pedigree-based analyses, we show that stripes and body elongation segregate independently, indicating that the two traits are not genetically linked. Their correlation in nature is therefore likely maintained by correlational selection. Lastly, by performing a mate preference assay using a striped CRISPR-Cas9 mutant of a nonstriped species, we show that females do not differentiate between striped CRISPR mutant males and nonstriped wild-type males, suggesting that these patterns might be less important for species recognition and mate choice. In summary, our study suggests that the massive rates of repeated evolution of stripe patterns are shaped by correlational selection with body elongation, but not by sexual selection.Peer reviewe

Evolutionary Dynamics of Structural Variation at a Key Locus for Color Pattern Diversification in Cichlid Fishes

Color patterns in African cichlid fishes vary spectacularly. Although phylogenetic analysis showed already 30 years ago that many color patterns evolved repeatedly in these adaptive radiations, only recently have we begun to understand the genomic basis of color variation. Horizontal stripe patterns evolved and were lost several times independently across the adaptive radiations of LakeVictoria, Malawi, and Tanganyika and regulatory evolution of agouti-related peptide 2 (agrp2/asip2b) has been linked to this phenotypically labile trait. Here, we asked whether the agrp2 locus exhibits particular characteristics that facilitate divergence in color patterns. Based on comparative genomic analyses, we discovered several recent duplications, insertions, and deletions. Interestingly, one of these events resulted in a tandem duplication of the last exon of agrp2. The duplication likely precedes the EastAfrican radiations that started 8-12 Ma, is not fixed within any of the radiations, and is found to vary even within some species. Moreover, we also observed variation in copy number (two to five copies) and secondary loss of the duplication, illustrating a surprising dynamic at this locus that possibly promoted functional divergence of agrp2. Our work suggests that such instances of exon duplications are a neglected mechanism potentially involved in the repeated evolution and diversification that deserves more attention.Peer reviewe