Predicting portal thrombosis in cirrhosis: A prospective study of clinical, ultrasonographic and hemostatic factors

BACKGROUND & AIMS

Portal vein thrombosis (PVT) is a relatively frequent event in patients with cirrhosis. While different risk factors for PVT have been reported, such as decreased portal blood flow velocity (PBFV) and parameters related with severity of portal hypertension, these are based on retrospective studies assessing only a discrete number of parameters. The aim of the current study was to evaluate the incidence and risks factors for non-tumoral PVT development in a large prospective cohort of patients with cirrhosis.

METHODS

We performed an exhaustive evaluation of clinical, biochemical, inflammatory and acquired/hereditary hemostatic profiles in 369 patients with cirrhosis without PVT who were prospectively followed-up. Doppler ultrasound was performed at baseline and every 6 months or whenever clinically indicated. PVT development was always confirmed by computed tomography.

RESULTS

Twenty-nine patients developed non-tumoral PVT, with an incidence of 1.6%, 6% and 8.4% at 1, 3 and 5 years, respectively. Low platelet count, PBFV <15 cm/sec and history of variceal bleeding were factors independently associated with a high PVT risk. No relationship between PVT development and any other clinical biochemical, inflammatory and acquired or hereditary hemostatic parameter was found.

CONCLUSIONS

In patients with cirrhosis, the factors predictive of PVT development were mainly those related to the severity of portal hypertension. Our results do not support the role of hemostatic alterations (inherited or acquired) and inflammatory markers in the prediction of PVT in patients with cirrhosis.

LAY SUMMARY

Patients with cirrhosis and more severe portal hypertension are at higher risk of non-tumoral portal vein thrombosis development. Acquired or inherited hemostatic disorders, as well as inflammatory status, do not seem to predict the development of portal vein thrombosis in patients with cirrhosis.

Identification of an Immune-specific Class of Hepatocellular Carcinoma, Based on Molecular Features

BACKGROUND & AIMS

Agents that induce an immune response against tumors by altering T-cell regulation have increased survival times of patients with advanced-stage tumors, such as melanoma or lung cancer. We aimed to characterize molecular features of immune cells that infiltrate hepatocellular carcinomas (HCCs) to determine whether these types of agents might be effective against liver tumors.

METHODS

We analyzed HCC samples from 956 patients. We separated gene expression profiles from tumor, stromal, and immune cells using a non-negative matrix factorization algorithm. We then analyzed the gene expression pattern of inflammatory cells in HCC tumor samples. We correlated expression patterns with the presence of immune cell infiltrates and immune regulatory molecules, determined by pathology and immunohistochemical analyses, in a training set of 228 HCC samples. We validated the correlation in a validation set of 728 tumor samples. Using data from 190 tumors in the Cancer Genome Atlas, we correlated immune cell gene expression profiles with numbers of chromosomal aberrations (based on single-nucleotide polymorphism array) and mutations (exome sequence data).

RESULTS

We found approximately 25% of HCCs to have markers of an inflammatory response, with high expression levels of the CD274 molecule (programmed death-ligand 1) and programmed cell death 1, markers of cytolytic activity, and fewer chromosomal aberrations. We called this group of tumors the Immune class. It contained 2 subtypes, characterized by markers of an adaptive T-cell response or exhausted immune response. The exhausted immune response subclass expressed many genes regulated by transforming growth factor beta 1 that mediate immunosuppression. We did not observe any differences in numbers of mutations or expression of tumor antigens between the immune-specific class and other HCCs.

CONCLUSIONS

In an analysis of HCC samples from 956 patients, we found almost 25% to express markers of an inflammatory response. We identified 2 subclasses, characterized by adaptive or exhausted immune responses. These findings indicate that some HCCs might be susceptible to therapeutic agents designed to block the regulatory pathways in T cells, such as programmed death-ligand 1, programmed cell death 1, or transforming growth factor beta 1 inhibitors.

Abstract 2936: Molecular characterization of the immune subclass of hepatocellualr carcinoma

Background: Immune checkpoint inhibitors have emerged as a promising therapeutic approach in different solid tumors, including hepatocellular carcinoma (HCC). Nonetheless, little is known about the immune-component of HCC or potential biomarkers of response to these therapies.

Aims: To perform comprehensive characterization of the HCC immunological profile and to identify biomarkers to select immunotherapy candidates.

Methods: We performed gene expression array deconvolution through non-negative matrix factorization in 228 resected HCCs. Characterization of the transcriptional landscape was conducted using &gt;1,000 signatures representing distinct immune cells by gene set enrichment and nearest template prediction analyses. Presence of immune infiltration, tertiary lymphoid structure (TLS), PD-1 and PD-L1 immunostainings was investigated using immunohistochemistry. DNA methylation profile of 450K CpG sites was analyzed to identify those with significant differences for each group. Extensive validation of the immune classifier was performed in 728 independent HCC samples.

Results: Overall, an immune-related subclass of HCC was identified in ~27% of patients. The immune subclass was characterized by gene signatures identifying immune cells (i.e. T cells, TLS, cytotox, p&lt;0.001), signatures of response to immune checkpoint therapy (p&lt;0.001), presence of high immune infiltration (p=0.01), TLS (≥5 foci, 19/51 vs 33/168, p=0.01) and PD-1 and PD-L1 protein expression (p&lt;0.05). The methylation levels of 363 CpG sites in 192 immune response gene promoters were able to capture the Immune class (ANOVA, p&lt;0.05, Δβ&gt;0.2 Tukey test). Integration with HCC molecular classifications revealed significant enrichment of the Immune subclass with IFN and S1 (p&lt;0.001) and exclusion of the CTNNB1 and S2 (p&lt;0.001) subclasses. The immune class contains two distinct microenvironment-based types: A) Exhausted immune response type (~35%) characterized by stromal activation, T cell exhaustion signatures, and presence of immunosuppressive components such as TGFB, LGALS1, M2 macrophages and pathways able to recruit myeloid-derived-suppressor cells (FDR&lt;0.01); and B) Active immune response type (~65%) characterized by overexpression of adaptive immune response genes and IFN signaling (p&lt;0.001). Tumors within the active immune response type showed a trend towards better survival vs rest (p=0.07).

Conclusions: Around 27% of HCC patients belong to the Immune class, characterized by activation of immune cells and signatures of response to immunotherapies. Within this subclass, two distinct types have been characterized by presenting active or exhausted immune responses, a feature that provides the rationale for precision medicine-based therapies.

Note: This abstract was not presented at the meeting.

Citation Format: Daniela Sia, Yang Jiao, Iris Martinez, Olga Kuchuk, Carlos Villacorta Martin, Manuel Castro de Moura, Juan Putra, Genis Camprecios, Swan Thung, Samuel Waxman, Vincenzo Mazzaferro, Manel Esteller, Augusto Villanueva, Josep Maria Llovet. Molecular characterization of the immune subclass of hepatocellualr carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2936. doi:10.1158/1538-7445.AM2017-2936

Abstract 3944: Characterization of molecular heterogeneity in hepatocellular carcinoma: Trunk and branch drivers

Introduction: Molecular heterogeneity occurs in Hepatocellular carcinoma (HCC), but its implications in clinical decision-making are unknown. The clonal evolution model explains that trunk alterations arise at early stages and are shared by all malignant cells, whereas branch alterations occur in subclonal tumoral cells. We aim to characterize the genomic landscape of HCC through the identification of trunk driver alterations and the study of its distribution in intra- and inter-tumor heterogeneity.

Methods: 153 HCC samples representing the multiple steps of hepatocarcinogenesis were analyzed by deep targeted-sequencing covering exonic and promoter regions of the most frequently mutated drivers in HCC. Genes mutated in early lesions [39 dysplastic nodules and 54 early HCCs (eHCC) defined as &lt;2cm, without satellites or vascular invasion] were classified as candidate trunk genes. Candidate trunk genes were further explored in two additional cohorts: a) intra-tumor heterogeneity cohort: 42 tumor regions of 21 tumors &gt;4cm (2-3 regions/tumor); and 2) inter-tumor heterogeneity cohort: 39 tumors from 17 patients with multinodular lesions (2-3 nodules/patient). Transcriptome and copy-number variations (CNVs) were analyzed using expression and SNP arrays, respectively.

Results: A total of 46 mutations were identified in the cohort of early lesions. Average number of mutations and CNV aberrations were higher in eHCCs than in dysplastic nodules [1.1 vs 0.5, mutations/patient (p=0.03), and 8% vs 0.6% of aberrant chromosomal arms (p&lt;0.0003), respectively]. Overall, 72% (23/32) of the sequenced eHCCs presented at least 1 trunk mutation, being TERT, TP53 and CTNNB1 the most frequent (21/23, 91%). In the intra-tumor heterogeneity cohort, 81% (17/21) tumors showed at least 1 shared mutation in TERT, TP53 and/or CTNNB1 between different tumor regions (trunk drivers). In the inter-tumor heterogeneity cohort, the similarity of the CNV-profile of multinodular tumors was used to classify them as clonal (intra-hepatic metastasis) or non-clonal (synchronic tumors). 6/17 (35%) of patients harbored clonal tumors according to their CNV profiles (Pearson p&lt;0.05). Clonality classification was further confirmed by gene expression-based hierarchical clustering. 82% (9/11) of the sequenced clonal tumors shared TERT, TP53 and/or CTNNB1 as trunk alterations. In contrast, no trunk mutations were shared across non-clonal tumors.

Conclusions: TERT, TP53 and CTNNB1 are trunk drivers mutated in early HCC tumors that remained as trunk aberrations across different regions of the same tumor and between primary and metastatic nodules. These mutations are early trunk drivers that can be captured with single biopsies and could represent ideal therapeutic targets in the future.

Citation Format: Sara Torrecilla, Daniela Sia, Andrew N. Harrington, Zhongyang Zhang, Genis Camprecios, Agrin Moeini, Toffanin Sara, Isabel Fiel, Ke Hao, Monica Higuera, Laia Cabellos, Helena Cornella, Milind Mahajan, Yujin Hoshida, Augusto Villanueva, Sander Florman, Myron Schwartz, Josep Llovet. Characterization of molecular heterogeneity in hepatocellular carcinoma: Trunk and branch drivers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3944. doi:10.1158/1538-7445.AM2017-3944

Mixed hepatocellular cholangiocarcinoma tumors: Cholangiolocellular carcinoma is a distinct molecular entity

BACKGROUND & AIMS

Mixed hepatocellular cholangiocarcinoma (HCC-CCA) is a rare and poorly understood type of primary liver cancer. We aimed to perform a comprehensive molecular characterization of this malignancy.

METHODS

Gene expression profiling, DNA copy number detection, and exome sequencing using formalin-fixed samples from 18 patients with mixed HCC-CCA were performed, encompassing the whole histological spectrum of the disease. Comparative genomic analysis was carried out, using independent datasets of HCC (n=164) and intrahepatic cholangiocarcinoma (iCCA) (n=149).

RESULTS

Integrative genomic analysis of HCC-CCAs revealed that cholangiolocellular carcinoma (CLC) represents a distinct biliary-derived entity compared with the stem-cell and classical types. CLC tumors were neural cell adhesion molecule (NCAM) positive (6/6 vs. 1/12, p<0.001), chromosomally stable (mean chromosomal aberrations 5.7 vs. 14.1, p=0.008), showed significant upregulation of transforming growth factor (TGF)-β signaling and enrichment of inflammation-related and immune response signatures (p<0.001). Stem-cell tumors were characterized by spalt-like transcription factor 4 (SALL4) positivity (6/8 vs. 0/10, p<0.001), enrichment of progenitor-like signatures, activation of specific oncogenic pathways (i.e., MYC and insulin-like growth factor [IGF]), and signatures related to poor clinical outcome. In the classical type, there was a significant correlation in the copy number variation of the iCCA and HCC components, suggesting a clonal origin. Exome sequencing revealed an average of 63 non-synonymous mutations per tumor (2 mean driver mutations per tumor). Among those, TP53 was the most frequently mutated gene (6/21, 29%) in HCC-CCAs.

CONCLUSIONS

Mixed HCC-CCA represents a heterogeneous group of tumors, with the stem-cell type characterized by features of poor prognosis, and the classical type with common lineage for HCC and iCCA components. CLC stands alone as a distinct biliary-derived entity associated with chromosomal stability and active TGF-β signaling.

LAY SUMMARY

Molecular analysis of mixed hepatocellular cholangiocarcinoma (HCC-CCA) showed that cholangiolocellular carcinoma (CLC) is distinct and biliary in origin. It has none of the traits of hepatocellular carcinoma (HCC). However, within mixed HCC-CCA, stem-cell type tumors shared an aggressive nature and poor outcome, whereas the classic type showed a common cell lineage for both the HCC and the intrahepatic CCA component. The pathological classification of mixed HCC-CCA should be redefined because of the new molecular data provided.

Abstract 2388: Molecular heterogeneity and trunk driver mutations in hepatocellular carcinoma

Background and aims: Molecular heterogeneity in hepatocellular carcinoma (HCC) is ill-defined since trunk drivers (early events; common to all cells), branch drivers (later events; present in a subset of cells) and passenger mutations (not relevant), have not been thoroughly described. Most FDA/EMA approved molecular drugs target trunk drivers. We explored heterogeneity by analyzing trunk vs branch mutations in different HCC regions within single and multinodular tumours.

Methods: Intra-tumoral heterogeneity was assessed in 21 patients with single HCCs (size &gt; 4cm; 2 regions/tumour: 42 samples) and inter-tumoral heterogeneity was studied in 17 patients with multinodular HCCs (2-3 nodules/patient; total: 39 samples). Gene expression profiling, SNP array and deep-sequencing (coverage ∼850x) assessing 6 oncodrivers (TERT promoter, TP53, CTNNB1, ARID1A, AXIN1-2 by TruSeqAmplicon, validated by sanger) were explored. Clonality differentiating metastatic (clonal) vs synchronic (non-clonal) tumours was defined by SNP profiles. Trunk mutations were defined as present in a) all regions of a given tumour, or b) in all nodules of metastatic-clonal tumours; all other were considered as branch.

Results: Intra-tumoral heterogeneity assessed by sequencing identified at least 1 oncodriver in 19/21 patients with single tumours. Among those, trunk mutations accounted for 17/19 (90%), and branch for 2/19 cases. Overall 63 mutations were identified, 56 (90%) were identical in different tumoral regions (i.e. truncal; TERT promoter most prevalent). Inter-tumoral heterogeneity explored by SNP profiles defined metastases in 35% (6/17 multinodular cases) and synchronous tumors in 65% (11/17 cases). Genetic proximity confirmed clonality in all metastatic nodules. Regarding molecular subclasses, half of clonal tumours retained identical molecular fingerprint, but the other half switched to more aggressive subclass. All non-clonal tumours belonged to distinct molecular subclasses. Driver oncogenes were explored in 9 patients (5 metastasis and 4 synchronic). Metastatic tumours showed 13 mutations, among which 11 (85%) were truncal. Mutations in non-clonal synchronic tumours were distinct.

Conclusions: Single large HCCs shared common trunk drivers at distinct regions (90%). Similarly, 40% of multinodular tumours were clonal (metastasis) and shared common trunk oncodrivers, while 60% were synchronic, with distinct genomic profile/oncodrivers. Further studies at single-cell sequencing level are recommended.

Citation Format: Daniela Sia, Andrew Neelis Harrington, Sara Torrecilla, Zhongyang Zhang, Genis Camprecios, Agrin Moeini, Sara Toffanin, Maria Isabel Fiel, Ke Hao, Monica Higuera, Laia Cabellos, Helena Cornella, Milind Mahajan, Yujin Hoshida, Augusto Villanueva, Sander Florman, Myron Schwartz, Josep Maria Llovet. Molecular heterogeneity and trunk driver mutations in hepatocellular carcinoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2388.

The exosome complex establishes a barricade to erythroid maturation

Complex genetic networks control hematopoietic stem cell differentiation into progenitors that give rise to billions of erythrocytes daily. Previously, we described a role for the master regulator of erythropoiesis, GATA-1, in inducing genes encoding components of the autophagy machinery. In this context, the Forkhead transcription factor, Foxo3, amplified GATA-1-mediated transcriptional activation. To determine the scope of the GATA-1/Foxo3 cooperativity, and to develop functional insights, we analyzed the GATA-1/Foxo3-dependent transcriptome in erythroid cells. GATA-1/Foxo3 repressed expression of Exosc8, a pivotal component of the exosome complex, which mediates RNA surveillance and epigenetic regulation. Strikingly, downregulating Exosc8, or additional exosome complex components, in primary erythroid precursor cells induced erythroid cell maturation. Our results demonstrate a new mode of controlling erythropoiesis in which multiple components of the exosome complex are endogenous suppressors of the erythroid developmental program.

ErbB receptors protect the perfused heart against injury induced by epinephrine combined with low-flow ischemia

ErbB receptor tyrosine kinases are important in maintaining the long-term structural integrity of the heart and in the induction of hypertrophy. In addition, in vivo activation of ErbB1 by epidermal growth factor (EGF) protects the heart against acute stress-induced damage. We examined here whether the ErbB sytem acutely protects the isolated heart in which stress was induced in vitro by ischemia combined with epinephrine infusion (EPI). In perfused mouse hearts, EGF induced Tyr-phosphorylation of ErbB1 but not ErbB2. Neuregulin-1beta (NRG-1beta) induced Tyr-phosphorylation of both ErbB4 and ErbB2. We also found differences in the signaling cascades activated by each growth factor. To stress the perfused mouse heart, we combined EPI with low-flow ischemia. This resulted in (i) loss of left ventricle contraction force ( + dP/dt(max)) and developed pressure (LVDP) after a short period of hypercontractility, (ii) enhanced anaerobic metabolism (lactate production), and (iii) myocyte injury (lactate dehydrogenase (LDH) release). EGF and NRG-1beta had different effects on stressed-heart contractility. EGF reduced to a half the loss of both + dP/dt(max) and LVDP. In contrast, NRG-1beta exacerbated the hypercontractility soon after reperfusion. This is coincident with a transient increase in coronary flow after reperfusion. In spite of these differences in contraction, both EGF and NRG-1beta induced similar early protection as shown by the reduction of LDH release. Our results show that the ErbB system protects the perfused heart against damage induced by acute stress. They reinforce the relevance of ErbB receptors and ligands in cardiac physiology.