Comprehensive and Integrative Genomic Characterization of Hepatocellular Carcinoma

Liver cancer has the second highest worldwide cancer mortality rate and has limited therapeutic options. We analyzed 363 hepatocellular carcinoma (HCC) cases by whole-exome sequencing and DNA copy number analyses, and we analyzed 196 HCC cases by DNA methylation, RNA, miRNA, and proteomic expression also. DNA sequencing and mutation analysis identified significantly mutated genes, including LZTR1, EEF1A1, SF3B1, and SMARCA4. Significant alterations by mutation or downregulation by hypermethylation in genes likely to result in HCC metabolic reprogramming (ALB, APOB, and CPS1) were observed. Integrative molecular HCC subtyping incorporating unsupervised clustering of five data platforms identified three subtypes, one of which was associated with poorer prognosis in three HCC cohorts. Integrated analyses enabled development of a p53 target gene expression signature correlating with poor survival. Potential therapeutic targets for which inhibitors exist include WNT signaling, MDM4, MET, VEGFA, MCL1, IDH1, TERT, and immune checkpoint proteins CTLA-4, PD-1, and PD-L1.

Environmental exposures as a risk factor for fibrolamellar carcinoma

Fibrolamellar carcinoma was first described in 1956. Subsequent large studies failed to identify cases before 1939 (the start of the World War II). This finding, combined with the presence of aryl hydrocarbon receptors on the tumor cells, have suggested that fibrolamellar carcinomas may be caused by environmental exposures that are new since World War II. To investigate this possibility, the surgical pathology files before 1939 were reviewed for hepatocellular carcinomas resected in young individuals. Two cases of fibrolamellar carcinoma were identified, from 1915 to 1924. The diagnosis of fibrolamellar carcinoma was confirmed at the histologic, ultrastructural and proteomic levels. These two fibrolamellar carcinoma cases clarify a key aspect of fibrolamellar carcinoma biology, reducing the likelihood that these tumors result exclusively from post World War II environmental exposures.

Clinical, Biochemical, and Histopathology Features of Patients With Glycogenic Hepatopathy

BACKGROUND & AIMS

Glycogenic hepatopathy, a syndrome characterized by hepatomegaly and increased liver transaminases in patients with type 1 diabetes, has not been well characterized in adults. We describe the clinical, biochemical, and histopathology profile of a cohort of patients with glycogenic hepatopathy. We also examined differences between patients with type 1 diabetes with versus without glycogenic hepatopathy.

METHODS

We performed a case-control study of patients with type 1 diabetes diagnosed with glycogenic hepatopathy and patients with type 1 diabetes without glycogenic hepatopathy (control subjects). Cases were identified in the database of electronic medical records at Mayo Clinic, Rochester from January 1, 1998, through January 1, 2014. Age- and sex-matched control subjects were identified from a Mayo Clinic registry of patients with type 1 diabetes who had normal levels of liver enzymes. Demographic, clinical, laboratory, and histopathology data were collected and compared between cases and control subjects. The primary outcome was difference in frequency of diabetic ketoacidosis episodes and hemoglobin (Hb) A_1c levels between cases and control subjects.

RESULTS

Among the 36 patients diagnosed with glycogenic hepatopathy, 20 had undergone liver biopsy analysis. Most cases were female (n = 28; 77.8%). Abdominal pain was the most common symptom (n = 23; 63.9%); 28 patients (77.8%) had hepatomegaly. All patients had poor control of diabetes (mean HbA_1c level, 11.2 ± 2.4%). A higher proportion of cases had recurrent episodes of diabetic ketoacidosis (61%) than control subjects (9%) (P = .009), and cases had a higher mean level of HbA_1c (11.2 ± 2.4% vs 9.0 ± 2.2% in control subjects; P = .0004). Adult cases had higher levels of aspartate transaminase (312.5 IU/L; range, 245.5-775 IU/L) than pediatric cases (157; range, 104-267 IU/L; P = .02) and lower serum levels of albumin (3.7 ± 0.5 g/dL vs 4.3 ± 0.4 g/dL for pediatric cases; P = .008). Only 16.7% of pediatric patients with glycogenic hepatopathy had growth retardation. Levels of liver transaminases were normalized at follow-up examinations of 18 of 21 adult or pediatric patients with glycogenic hepatopathy.

CONCLUSIONS

More than half of patients with glycogenic hepatopathy and type 1 diabetes have recurrent episodes of diabetic ketoacidosis, and these patients have higher levels of HbA_1c than patients with type 1 diabetes without glycogenic hepatopathy. We observed growth retardation in only about 17% of pediatric patients with glycogenic hepatopathy.

Morphologic Subtypes of Hepatocellular Carcinoma

Hepatocellular carcinomas can be further divided into distinct subtypes that provide important clinical information and biological insights. These subtypes are distinct from growth patterns and are on based on morphologic and molecular findings. There are 12 reasonably well-defined subtypes as well as 6 provisional subtypes, together making up 35% of all hepatocellular carcinomas. These subtypes are discussed, with an emphasis on their definitions and the key morphologic findings.

Factors associated with villus atrophy in symptomatic coeliac disease patients on a gluten-free diet

BACKGROUND

Duodenal injury persists in some coeliac disease patients despite gluten-free diet, and is associated with adverse outcomes.

AIM

To determine the prevalence and clinical risk factors for persistent villus atrophy among symptomatic coeliac disease patients.

METHODS

A nested cross-sectional analysis was performed on coeliac disease patients with self-reported moderate or severe symptoms while following a gluten-free diet, who underwent protocol-mandated duodenal biopsy upon enrolment in the CeliAction clinical trial. Demographic factors, symptom type, medication use, and serology were examined to determine predictors of persistent villus atrophy.

RESULTS

Of 1345 symptomatic patients, 511 (38%, 95% CI, 35-41%) were found to have active coeliac disease with persistent villus atrophy, defined as average villus height to crypt depth ratio ≤2.0. On multivariable analysis, older age (OR, 5.1 for ≥70 vs. 18-29 years, 95% CI, 2.5-10.4) was a risk factor while longer duration on gluten-free diet was protective (OR, 0.37, 95% CI, 0.24-0.55 for 4-5.9 vs. 1-1.9 years). Villus atrophy was associated with use of proton-pump inhibitors (PPIs; OR, 1.6, 95% CI, 1.1-2.3), non-steroidal anti-inflammatory drugs (NSAIDs; OR, 1.64, 95% CI, 1.2-2.2), and selective serotonin reuptake inhibitors (SSRIs; OR, 1.74, 95% CI, 1.2-2.5). Symptoms were not associated with villus atrophy after adjusting for covariates. Conclusions A majority of symptomatic coeliac disease patients did not have active disease on follow-up histology. Symptoms were poorly predictive of persistent mucosal injury. The impact of NSAIDs, PPIs, and SSRIs on mucosal healing in coeliac disease warrants further study.

Integrative Genomic Analysis of Cholangiocarcinoma Identifies Distinct IDH-Mutant Molecular Profiles

Cholangiocarcinoma (CCA) is an aggressive malignancy of the bile ducts, with poor prognosis and limited treatment options. Here, we describe the integrated analysis of somatic mutations, RNA expression, copy number, and DNA methylation by The Cancer Genome Atlas of a set of predominantly intrahepatic CCA cases and propose a molecular classification scheme. We identified an IDH mutant-enriched subtype with distinct molecular features including low expression of chromatin modifiers, elevated expression of mitochondrial genes, and increased mitochondrial DNA copy number. Leveraging the multi-platform data, we observed that ARID1A exhibited DNA hypermethylation and decreased expression in the IDH mutant subtype. More broadly, we found that IDH mutations are associated with an expanded histological spectrum of liver tumors with molecular features that stratify with CCA. Our studies reveal insights into the molecular pathogenesis and heterogeneity of cholangiocarcinoma and provide classification information of potential therapeutic significance.

Aberrant CDX2 expression in hepatocellular carcinomas: an important diagnostic pitfall

CDX2 is a sensitive and specific marker of intestinal differentiation. It is routinely used in surgical pathology, as its expression within a tumor favors an origin within the gastrointestinal tract. We had anecdotally encountered occasional hepatocellular carcinomas (HCCs) that were CDX2 positive. CDX2 expression in HCC has not yet been reported, but it has also not been examined in detail. Therefore, we evaluated CDX2 expression in a large number of resected HCCs. Full tumor sections from 172 resected HCCs and 6 resected fibrolamellar carcinomas (FLCs) were stained for CDX2. Nine (5.2%) of 172 HCCs were positive for CDX2, whereas all 6 FLCs were negative. CDX2 expression in HCCs was more commonly seen in poorly differentiated tumors (5 of 16 cases, 31%) than well and moderately differentiated tumors (4 of 156 cases, 2.5%), P = .0004. No other statistically significant correlations were observed (P>.05). Results of our study show that a small subset (5%) of HCCs can be CDX2 positive. Awareness of this phenomenon is important because CDX2 expression in a liver tumor does not completely exclude a diagnosis of HCC.

Fibrolamellar carcinoma: A histologically unique tumor with unique molecular findings

Fibrolamellar carcinoma is a unique type of hepatocellular carcinoma with a distinctive predilection for young patients without underlying liver disease, characteristic large neoplastic cells with intervening, dense fibrosis, co-expression of keratin 7 and CD68 and activation of protein kinase A (most often by formation of DNAJB1-PRKACA). Fibrolamellar carcinoma has a similar prognosis to conventional hepatocellular carcinomas arising in non-cirrhotic livers. The current American Joint Cancer Committee staging system does not provide optimal stratification of patients with fibrolamellar carcinoma and an alternate systems should be considered in the future. The only effective treatment for fibrolamellar carcinoma is complete resection. Novel therapies may be on the horizon as investigation into the molecular biology of fibrolamellar carcinoma continues.

Antitumor effect of FGFR inhibitors on a novel cholangiocarcinoma patient derived xenograft mouse model endogenously expressing an FGFR2-CCDC6 fusion protein

Cholangiocarcinoma is a highly lethal cancer with limited therapeutic options. Recent genomic analysis of cholangiocarcinoma has revealed the presence of fibroblast growth factor receptor 2 (FGFR2) fusion proteins in up to 13% of intrahepatic cholangiocarcinoma (iCCA). FGFR fusions have been identified as a novel oncogenic and druggable target in a number of cancers. In this study, we established a novel cholangiocarcinoma patient derived xenograft (PDX) mouse model bearing an FGFR2-CCDC6 fusion protein from a metastatic lung nodule of an iCCA patient. Using this PDX model, we confirmed the ability of the FGFR inhibitors, ponatinib, dovitinib and BGJ398, to modulate FGFR signaling, inhibit cell proliferation and induce cell apoptosis in cholangiocarcinoma tumors harboring FGFR2 fusions. In addition, BGJ398 appeared to be superior in potency to ponatinib and dovitinib in this model. Our findings provide a strong rationale for the investigation of FGFR inhibitors, particularly BGJ398, as a therapeutic option for cholangiocarcinoma patients harboring FGFR2 fusions.

Silent Tyrosinemia Type I Without Elevated Tyrosine or Succinylacetone Associated with Liver Cirrhosis and Hepatocellular Carcinoma

Tyrosinemia type I (TYRSN1, TYR I) is caused by fumarylacetoacetate hydrolase (FAH) deficiency and affects approximately one in 100,000 individuals worldwide. Pathogenic variants in FAH cause TYRSN1, which induces cirrhosis and can progress to hepatocellular carcinoma (HCC). TYRSN1 is characterized by the production of a pathognomonic metabolite, succinylacetone (SUAC) and is included in the Recommended Uniform Screening Panel for newborns. Treatment intervention is effective if initiated within the first month of life. Here, we describe a family with three affected children who developed HCC secondary to idiopathic hepatosplenomegaly and cirrhosis during infancy. Whole exome sequencing revealed a novel homozygous missense variant in FAH (Chr15(GRCh38):g.80162305A>G; NM_000137.2:c.424A > G; NP_000128.1:p.R142G). This novel variant involves the catalytic pocket of the enzyme, but does not result in increased SUAC or tyrosine, making the diagnosis of TYRSN1 problematic. Testing this novel variant using a rapid, in vivo somatic mouse model showed that this variant could not rescue FAH deficiency. In this case of atypical TYRSN1, we show how reliance on SUAC as a primary diagnostic test can be misleading in some patients with this disease. Augmentation of current screening for TYRSN1 with targeted sequencing of FAH is warranted in cases suggestive of the disorder.

Khat chewing and cirrhosis in Somaliland: Case series

BACKGROUND

Khat chewing is common especially among men in East Africa and Yemen. It is generally viewed by the populace as a benign social custom. Several studies of ethnic Somali immigrants to Western countries suggest an association between khat chewing and hepatotoxicity, but the risk of hepatotoxicity related to khat chewing within African settings is not documented.

AIM

To identify and describe liver disease without evidence of alcohol exposure or infectious etiology in khat chewers.

SETTINGS

A university-affiliated teaching hospital in Somaliland.

METHODS

Cases of cirrhosis of unknown cause were identified from the clinical practice of Al Hayatt Hospital in Borama, Somaliland, during 14 months beginning December 2012.

RESULTS

Eight Somali men aged 27-70 years living in Somaliland were identified with cirrhosis of otherwise unknown cause. All chewed khat habitually for many years (15-128 bundles per day times years of use). A liver biopsy of one man was consistent with khat hepatotoxicity. Four of the eight men died during the study period.

CONCLUSION

Khat chewing may be associated with health consequences including severe hepatotoxicity with cirrhosis.

Exercise Prevents Diet-Induced Cellular Senescence in Adipose Tissue

Considerable evidence implicates cellular senescence in the biology of aging and chronic disease. Diet and exercise are determinants of healthy aging; however, the extent to which they affect the behavior and accretion of senescent cells within distinct tissues is not clear. Here we tested the hypothesis that exercise prevents premature senescent cell accumulation and systemic metabolic dysfunction induced by a fast-food diet (FFD). Using transgenic mice that express EGFP in response to activation of the senescence-associated p16(INK4a) promoter, we demonstrate that FFD consumption causes deleterious changes in body weight and composition as well as in measures of physical, cardiac, and metabolic health. The harmful effects of the FFD were associated with dramatic increases in several markers of senescence, including p16, EGFP, senescence-associated β-galactosidase, and the senescence-associated secretory phenotype (SASP) specifically in visceral adipose tissue. We show that exercise prevents the accumulation of senescent cells and the expression of the SASP while nullifying the damaging effects of the FFD on parameters of health. We also demonstrate that exercise initiated after long-term FFD feeding reduces senescent phenotype markers in visceral adipose tissue while attenuating physical impairments, suggesting that exercise may provide restorative benefit by mitigating accrued senescent burden. These findings highlight a novel mechanism by which exercise mediates its beneficial effects and reinforces the effect of modifiable lifestyle choices on health span.

Hepatic adenomas with synchronous or metachronous fibrolamellar carcinomas: both are characterized by LFABP loss

Rare hepatic adenomas are associated with synchronous or metachronous fibrolamellar carcinomas. The morphology of these adenomas has not been well described and they have not been subclassifed using the current molecular classification schema. We examined four hepatic adenomas co-occurring with or preceding a diagnosis of fibrolamellar carcinoma in three patients. On histological examination, three of the adenomas showed the typical morphology of HNF1-α inactivated adenomas, whereas one showed a myxoid adenoma morphology. All of the adenomas were negative for PRKACA rearrangements by Fluorescence in situ Hybridization (FISH) analysis. All four of the adenomas showed complete loss or significant reduction of liver fatty acid binding protein (LFABP) expression by immunohistochemistry. Interestingly, the fibrolamellar carcinomas in each case also showed loss of LFABP by immunohistochemistry. One of the fibrolamellar carcinomas was negative for PRKACA rearrangements by FISH, whereas the others were positive. To investigate if LFBAP loss is typical of fibrolamellar carcinomas in general, an additional cohort of tumors was studied (n=19). All 19 fibrolamellar carcinomas showed the expected PRKACA rearrangements and immunostains showed loss of LFABP in each case, consistent with HNF1-α inactivation. To validate this observation, mass spectrometry-based proteomics was performed on tumor-normal pairs of six fibrolamellar carcinomas and showed an average 10-fold reduction in LFABP protein levels, compared with matched normal liver tissue. In conclusion, hepatic adenomas co-occurring with fibrolamellar carcinomas show LFABP loss and are negative for PRKACA rearrangements, indicating they are genetically distinct lesions. These data also demonstrate that LFABP loss, which characterizes HNF1-α inactivation, is a consistent feature of fibrolamellar carcinoma, indicating HNF1-α inactivation is an important event in fibrolamellar carcinoma pathogenesis.

Pseudogene INTS6P1 regulates its cognate gene INTS6 through competitive binding of miR-17-5p in hepatocellular carcinoma

The complex regulation of tumor suppressive gene and its pseudogenes play key roles in the pathogenesis of hepatocellular cancer (HCC). However, the roles played by pseudogenes in the pathogenesis of HCC are still incompletely elucidated. This study identifies the putative tumor suppressor INTS6 and its pseudogene INTS6P1 in HCC through the whole genome microarray expression. Furthermore, the functional studies – include growth curves, cell death, migration assays and in vivo studies – verify the tumor suppressive roles of INTS6 and INTS6P1 in HCC. Finally, the mechanistic experiments indicate that INTS6 and INTS6P1 are reciprocally regulated through competition for oncomiR-17-5p. Taken together, these findings demonstrate INTS6P1 and INTS6 exert the tumor suppressive roles through competing for oncomiR-17-5p. Our investigation of this regulatory circuit reveals novel insights into the underlying mechanisms of hepatocarcinogenesis.

Lysyl Oxidase as a Serum Biomarker of Liver Fibrosis in Patients with Severe Obesity and Obstructive Sleep Apnea

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) is associated with the progression of nonalcoholic fatty liver disease (NAFLD). We hypothesized that the hypoxia of OSA increases hepatic production of lysyl oxidase (LOX), an enzyme that cross-links collagen, and that LOX may serve as a biomarker of hepatic fibrosis.

DESIGN

Thirty-five patients with severe obesity underwent liver biopsy, polysomnography, and serum LOX testing. A separate group with severe OSA had serum LOX measured before and after 3 mo of CPAP or no therapy, as did age-matched controls. LOX expression and secretion were measured in mouse hepatocytes following exposure to hypoxia.

SETTING

The Johns Hopkins Bayview Sleep Disorders Center, and the Hypertension Unit of the Heart Institute at the University of São Paulo Medical School.

MEASUREMENTS AND RESULTS

In the bariatric cohort, the apnea-hypopnea index was higher in patients with hepatic fibrosis than in those without fibrosis (42.7 ± 30.2 events/h, versus 16.2 ± 15.5 events/h; P = 0.002), as was serum LOX (84.64 ± 29.71 ng/mL, versus 45.46 ± 17.16 ng/mL; P < 0.001). In the sleep clinic sample, patients with severe OSA had higher baseline LOX than healthy controls (70.75 ng/mL versus 52.36 ng/mL, P = 0.046), and serum LOX decreased in patients with OSA on CPAP (mean decrease 20.49 ng/mL) but not in untreated patients (mean decrease 0.19 ng/mL). Hypoxic mouse hepatocytes demonstrated 5.9-fold increased LOX transcription (P = 0.046), and enhanced LOX protein secretion.

CONCLUSIONS

The hypoxic stress of obstructive sleep apnea may increase circulating lysyl oxidase (LOX) levels. LOX may serve as a biomarker of liver fibrosis in patients with severe obesity and nonalcoholic fatty liver disease.

DNAJB1-PRKACA is specific for fibrolamellar carcinoma

Fibrolamellar carcinoma is a distinct subtype of hepatocellular carcinoma that predominantly affects young patients without underlying cirrhosis. A recurrent DNAJB1-PRKACA fusion has recently been reported in fibrolamellar carcinomas. To determine the specificity of this fusion and to develop routinely available clinical methods of detection, we developed an RT-PCR assay for paraffin-embedded tissues and a FISH probe for detection of the rearrangements of the PRKACA locus. We also developed an RNA in situ hybridization assay to assess expression levels of the total chimeric transcript and wild-type transcripts. A total of 106 primary liver tumors were studied by RT-PCR, including 26 fibrolamellar carcinomas (4 of which were metastases to the abdominal wall or lymph nodes), 25 conventional hepatocellular carcinomas, 25 cholangiocarcinomas, 25 hepatic adenomas, and 5 hepatoblastomas. RT-PCR was successful in 92% of tested fibrolamellar carcinoma cases (24/26) and the DNAJB1-PRKACA fusion transcript was found in all fibrolamellar carcinomas but not in other tumor types. FISH was tested in 19 fibrolamellar carcinomas and in 6 scirrhous hepatocellular carcinomas, which can closely mimic fibrolamellar carcinoma. Rearrangements of the PRKACA locus was seen in all 19 fibrolamellar carcinoma specimens, but in none of the scirrhous hepatocellular carcinomas. Finally, a RNA in situ hybridization strategy was positive in 7/7 successfully hybridized cases, and showed mRNA over-expression in all of the fibrolamellar carcinomas. In addition, the stromal cells embedded in the characteristic intratumoral fibrosis of fibrolamellar carcinomas and the background liver tissues were negative for the DNAJB1-PRKACA fusion by all tested methods. In conclusion, detection of DNAJB1-PRKACA is a very sensitive and specific finding in support of the diagnosis of fibrolamellar carcinoma.

Primary hepatic tumors with myxoid change: morphologically unique hepatic adenomas and hepatocellular carcinomas

Mucin production in primary liver neoplasms is typically interpreted as evidence for biliary differentiation. However, we have observed benign and malignant liver tumors that have abundant extracellular myxoid/mucinous material, yet have only evidence of hepatocellular differentiation. To further characterize these unusual findings, 9 cases were identified and further studied. Four cases were hepatic adenomas, whereas 5 were hepatocellular carcinomas. Extracellular myxoid/mucinous material was diffuse in 7 cases and patchy in 2 cases. The extracellular myxoid/mucinous material was typically weakly mucicarmine positive (N=6) and Alcian blue positive (N=8). All tumors were well differentiated, and none had evidence for biliary differentiation by morphology or immunohistochemistry. The hepatic adenomas arose in nondiabetic and nonobese patients. Both the hepatic adenomas and the hepatocellular carcinomas were strongly and diffusely HepPar1 positive, CK19 negative, and showed loss of LFABP protein expression. These findings indicate that extracellular myxoid/mucinous material in isolation should not be interpreted as cholangiocarcinoma. Furthermore, the unique morphology, the clinical characteristics, and the immunophenotype results suggest that myxoid hepatic adenomas and hepatocellular carcinoma may be unique tumor variants.

Occurrence of a multimeric high-molecular-weight glyceraldehyde-3-phosphate dehydrogenase in human serum

Cellular glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a phylogenetically conserved, ubiquitous enzyme that plays an indispensable role in energy metabolism. Although a wealth of information is available on cellular GAPDH, there is a clear paucity of data on its extracellular counterpart (i.e., the secreted or extracellular GAPDH). Here, we show that the extracellular GAPDH in human serum is a multimeric, high-molecular-weight, yet glycolytically active enzyme. The high-molecular-weight multimers of serum GAPDH were identified by immunodetection on one- and two-dimensional gel electrophoresis using multiple antibodies specific for various epitopes of GAPDH. Partial purification of serum GAPDH by DEAE Affigel affinity/ion exchange chromatography further established the multimeric composition of serum GAPDH. In vitro data demonstrated that human cell lines secrete a multimeric, high-molecular-weight enzyme similar to that of serum GAPDH. Furthermore, LC-MS/MS analysis of extracellular GAPDH from human cell lines confirmed the presence of unique peptides of GAPDH in the high-molecular-weight subunits. Furthermore, data from pulse-chase experiments established the presence of high-molecular-weight subunits in the secreted, extracellular GAPDH. Taken together, our findings demonstrate the presence of a high-molecular-weight, enzymatically active secretory GAPDH in human serum that may have a hitherto unknown function in humans.

Long interspersed element-1 protein expression is a hallmark of many human cancers

Cancers comprise a heterogeneous group of human diseases. Unifying characteristics include unchecked abilities of tumor cells to proliferate and spread anatomically, and the presence of clonal advantageous genetic changes. However, universal and highly specific tumor markers are unknown. Herein, we report widespread long interspersed element-1 (LINE-1) repeat expression in human cancers. We show that nearly half of all human cancers are immunoreactive for a LINE-1-encoded protein. LINE-1 protein expression is a common feature of many types of high-grade malignant cancers, is rarely detected in early stages of tumorigenesis, and is absent from normal somatic tissues. Studies have shown that LINE-1 contributes to genetic changes in cancers, with somatic LINE-1 insertions seen in selected types of human cancers, particularly colon cancer. We sought to correlate this observation with expression of the LINE-1-encoded protein, open reading frame 1 protein, and found that LINE-1 open reading frame 1 protein is a surprisingly broad, yet highly tumor-specific, antigen.

Pathology of the liver sinusoids

The hepatic sinusoids comprise a complex of vascular conduits to transport blood from the porta hepatis to the inferior vena cava through the liver. Under normal conditions, portal venous and hepatic artery pressures are equalized within the sinusoids, oxygen and nutrients from the systemic circulation are delivered to the parenchymal cells and differentially distributed throughout the liver acini, and proteins of liver derivation are carried into the cardiac/systemic circulation. Liver sinusoid structures are lined by endothelial cells unique to their location, and Kupffer cells. Multifunctional hepatic stellate cells and various immune active cells are localized within the space of Disse between the sinusoid and the adjacent hepatocytes. Flow within the sinusoids can be compromised by physical or pressure blockage in their lumina as well as obstructive processes within the space of Disse. The intimate relationship of the liver sinusoids to neighbouring hepatocytes is a significant factor affecting the health of hepatocytes, or transmission of the effects of injury within the sinusoidal space. Pathologists should recognize several patterns of injury involving the sinusoids and surrounding hepatocytes. In this review, injury, alterations and accumulations within the liver sinusoids are illustrated and discussed.