Oleksiy Tsybrovskyy

Role of farnesoid X receptor in determining hepatic ABC transporter expression and liver injury in bile duct-ligated mice

BACKGROUND & AIMS Cholestasis induces changes in hepatic adenosine triphosphate-binding cassette (ABC) transporter expression. We aimed to investigate the role of the nuclear bile acid receptor (farnesoid X receptor [FXR]) in mediating changes in ABC transporter expression and in determining liver injury. METHODS Hepatic ABC transporter (multidrug resistance-associated proteins [Mrp] 2-4 and bile salt export pump [Bsep]) expression and localization were studied in common bile duct-ligated (CBDL) FXR knockout (FXR(-/-)), wild-type (FXR(+/+)), and sham-operated mice. Serum alanine aminotransferase, alkaline phosphatase, bilirubin and bile acid levels, hepatic bile acid composition, and liver histology were investigated. Cholangiomanometry and bile duct morphometry were performed. RESULTS CBDL induced expression of Mrp 3 and Mrp 4 in FXR(+/+) and even more in FXR(-/-), whereas Mrp 2 expression remained unchanged. Bsep expression was maintained in CBDL FXR(+/+) but remained undetectable in CBDL FXR(-/-). Alanine aminotransferase levels and mortality rates did not differ between CBDL FXR(+/+) and FXR(-/-). CBDL increased biliary pressure and induced bile ductular proliferation and bile infarcts in FXR(+/+), whereas FXR(-/-) had lower biliary pressures, less ductular proliferation, and developed disseminated liver cell necroses. CONCLUSIONS Overexpression of Mrp 3 and Mrp 4 in CBDL mice is FXR independent and could play an important role in the adaptive hepatic ABC transporter response to cholestasis. Maintenance of Bsep expression strictly depends on FXR and is a critical determinant of the cholestatic phenotype. Lack of bile infarcts in CBDL FXR(-/-) suggests that development of bile infarcts is related to bile acid-dependent bile flow and biliary pressure. This information is relevant for the potential use of FXR modulators in the treatment of cholestatic liver diseases.

Farnesoid X Receptor Critically Determines the Fibrotic Response in Mice but Is Expressed to a Low Extent in Human Hepatic Stellate Cells and Periductal Myofibroblasts

The nuclear bile acid receptor, farnesoid X receptor (FXR), may play a pivotal role in liver fibrosis. We tested the impact of genetic FXR ablation in four different mouse models. Hepatic fibrosis was induced in wild-type and FXR knock-out mice (FXR(-/-)) by CCl(4) intoxication, 3,5-diethoxycarbonyl-1,4-dihydrocollidine feeding, common bile duct ligation, or Schistosoma mansoni (S.m.)-infection. In addition, we determined nuclear receptor expression levels (FXR, pregnane X receptor (PXR), vitamin D receptor, constitutive androstane receptor (CAR), small heterodimer partner (SHP)) in mouse hepatic stellate cells (HSCs), portal myofibroblasts (MFBs), and human HSCs. Cell type-specific FXR protein expression was determined by immunohistochemistry in five mouse models and prototypic human fibrotic liver diseases. Expression of nuclear receptors was much lower in mouse and human HSCs/MFBs compared with total liver expression with the exception of vitamin D receptor. FXR protein was undetectable in mouse and human HSCs and MFBs. FXR loss had no effect in CCl(4)-intoxicated and S.m.-infected mice, but significantly decreased liver fibrosis of the biliary type (common bile duct ligation, 3,5-diethoxycarbonyl-1,4-dihydrocollidine). These data suggest that FXR loss significantly reduces fibrosis of the biliary type, but has no impact on non-cholestatic liver fibrosis. Since there is no FXR expression in HSCs and MFBs in liver fibrosis, our data indicate that these cells may not represent direct therapeutic targets for FXR ligands.

Prognostic relevance of tumour-associated macrophages and von Willebrand factor-positive microvessels in colorectal cancer

Tumour-associated macrophages (TAM) are involved in tumour angiogenesis and anti-tumour immune response. In colorectal cancer (CRC), an association of high microvascular density (MVD) and unfavourable prognosis has been reported by some investigators. However, heterogeneous patient groups were studied. We, therefore, analysed the correlation between TAM and MVD and the prognostic relevance of MVD, TAM and T lymphocyte infiltration for long-term survival in a homogeneous group of 70 patients with moderately differentiated cancers of the International Union Against Cancer (UICC) stages II and III, who did not receive chemotherapy. MVD was evaluated using immunohistochemistry with antibodies against CD34 and von Willebrand factor (vWF). TAM and T lymphocytes were visualised with antibodies against CD68 and CD3, respectively. Statistical analysis did not reveal a significant correlation between TAM and T lymphocyte numbers and MVD. Multivariate analysis of immunohistochemical data from all CRC patients and the subgroup of patients with UICC stage-II CRC identified TAM- and vWF-positive microvessel numbers as prognostically relevant markers. Low numbers of TAM- and high numbers of vWF-positive microvessels were associated with an unfavourable prognosis. In conclusion, TAM- and vWF-positive microvessel numbers may serve as independent prognostic markers for patients with UICC stage-II and -III CRC and may help to identify patients with an unfavourable prognosis.

P63 Immunoreactivity Distinguishes Upper Urinary Tract Transitional-cell Carcinoma and Renal-cell Carcinoma Even in Poorly Differentiated Tumors

P63 is essential for the differentiation of normal urothelium and is also expressed in transitional cell carcinoma (TCC) of the bladder. We investigated p63 immunoreactivity in upper urinary tract TCC (n = 53) and in renal-cell carcinoma (RCC; n = 188) using a tissue microarray technique. P63 expression was detected in 51/53 (96.2%) TCCs, showing decreased expression in high-stage (pT1 and pT2 100%; pT3 90.9%) and poorly differentiated (G1 and G2 100%; G3 92%) tumors. All RCCs were negative for p63. P63 proved to be a helpful tool, even in poorly differentiated and undifferentiated renal malignancies, to distinguish TCC from RCC.

Microsatellite analysis of breast carcinoma and corresponding local recurrences.

Local recurrence is a serious complication of breast carcinoma that reduces quality of life and influences prognosis. The aim of this study was to determine whether local recurrences of breast carcinoma are genetically related to the primary tumours. Forty cases of locally recurrent breast carcinomas (median onset: 3.6 years after primary surgery) were analysed: 22 patients had undergone breast‐conserving therapy and 18 mastectomy. Eighteen microsatellites on chromosomes 2p, 3p, 5q, 10q, 11p, 11q, 13q, 17q, 17p, 18p were amplified by PCR using fluorescent‐labelled primers, automatically detected after polyacrylamide gel electrophoresis and analysed for loss of heterozygosity (LOH) or microsatellite instability (MSI). Follow‐up data were available for 39 cases with a median value of 89 months. All LOH and MSI found in the primary tumours were also present in the corresponding recurrences, indicating that they are genetically related to the primary tumours and not secondary malignancies in the same breast. MSI was found in three cases, of which one harboured MSI at more than two loci. The median value of LOH per case was significantly higher in the recurrent (four per case) compared to the primary tumours (two per case; p < 0.001, Mann–Whitney test), reflecting the genotype of tumour progression. Early local recurrence was associated with specific LOH for TP53.15 (p = 0.018, log‐rank test) in the primary tumours. LOH on D13S1699 or D17S855 was associated with lymph node metastases (p = 0.024 and p = 0.019, respectively; chi‐square test). In addition, tumour grade, lack of oestrogen or progesterone receptor expression, young patient age and early appearance of local recurrence significantly correlated with poor survival. The development of local recurrence despite clear resection margins may result from residual DCIS distant from the invasive carcinoma, homing of circulating tumour cells, or genetically altered, histologically normal breast tissue not immediately adjacent to the invasive carcinoma. Copyright

The Role of Osteopontin and Tumor Necrosis Factor Alpha Receptor-1 in Xenobiotic-induced Cholangitis and Biliary Fibrosis in Mice

Proinflammatory and profibrotic cytokines such as osteopontin (OPN) and tumor necrosis factor-alpha receptor-1 (TNFR1) may be critically involved in the pathogenesis of cholangiopathies and biliary fibrosis. We therefore aimed to determine the role of genetic loss of either OPN or TNFR1 in 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC)-fed mice as a model of xenobiotic-induced sclerosing cholangitis with biliary-type liver fibrosis using respective knock-out mice. OPN and TNFR1 knock-out mice were fed a 0.1% DDC-supplemented diet for 4 weeks and compared with corresponding wild-type (WT) controls. Liver morphology (H&E staining), serum markers of liver injury and cholestasis (ALT, AP, bilirubin), markers of inflammation in liver (CD11b and F4/80 immunostaining, mRNA expression of iNOS, MCP-1, IL-1β, INF-γ, TNF-α and OPN), degree of ductular reaction (immunohistochemistry with morphometric analysis and western blotting for cholangiocyte-specific marker keratin 19) and degree of liver fibrosis (Sirius-red staining, hepatic hydroxyproline content for quantification) were compared between groups. DDC feeding in OPN and TNFR1 knock-out mice and respective WT controls resulted in comparable extent of liver injury, inflammatory response, ductular reaction and liver fibrosis. Our data indicate that genetic loss of neither OPN nor TNFR1 significantly effects on the pathogenesis of DDC-induced sclerosing cholangitis, ductular reaction and resulting biliary fibrosis.

Genetic background effects of keratin 8 and 18 in a DDC-induced hepatotoxicity and Mallory-Denk body formation mouse model

Keratin 8 (K8) and keratin 18 (K18) form the major hepatocyte cytoskeleton. We investigated the impact of genetic loss of either K8 or K18 on liver homeostasis under toxic stress with the hypothesis that K8 and K18 exert different functions. krt8−/− and krt18−/− mice crossed into the same 129-ola genetic background were treated by acute and chronic administration of 3,5-diethoxy-carbonyl-1,4-dihydrocollidine (DDC). In acutely DDC-intoxicated mice, macrovesicular steatosis was more pronounced in krt8−/− and krt18−/− compared with wild-type (wt) animals. Mallory-Denk bodies (MDBs) appeared in krt18−/− mice already at an early stage of intoxication in contrast to krt8−/− mice that did not display MDB formation when fed with DDC. Keratin-deficient mice displayed significantly lower numbers of apoptotic hepatocytes than wt animals. krt8−/−, krt18−/− and control mice displayed comparable cell proliferation rates. Chronically DDC-intoxicated krt18−/− and wt mice showed a similarly increased degree of steatohepatitis with hepatocyte ballooning and MDB formation. In krt8−/− mice, steatosis was less, ballooning, and MDBs were absent. krt18−/− mice developed MDBs whereas krt8−/− mice on the same genetic background did not, highlighting the significance of different structural properties of keratins. They are independent of the genetic background as an intrinsic factor. By contrast, toxicity effects may depend on the genetic background. krt8−/− and krt18−/− mice on the same genetic background show similar sensitivity to DDC intoxication and almost resemble wt animals regarding survival, degree of porphyria, liver-to-body weight ratio, serum bilirubin and liver enzyme levels. This stands in contrast to previous work where krt8−/− and krt18−/− mice on different genetic backgrounds were investigated.

Androgen receptor expression in breast cancer patients tested for BRCA1 and BRCA2 mutations.

Pristauz G, Petru E, Stacher E, Geigl J B, Schwarzbraun T, Tsybrovskyy O, Winter R & Moinfar F
(2010) Histopathology57, 877–884

Cytokeratin typing as an aid in the differential diagnosis of primary versus metastatic lung carcinomas, and comparison with normal lung

Due to more efficient chemotherapy protocols, the number of second and even third primary carcinomas is steadily increasing. To denominate the possible origin of a carcinoma, different markers are available as an aid, e.g. hormones, proteins and lipoproteins, secretion products and cytoskeletal proteins. Cytokeratins (CKs) have gained new popularity; however, they have not been extensively evaluated in lung tumours. In our study we evaluated the staining patterns of CK polypeptides 4–8, 10, 13, 14, and 17–20 and high molecular weight (HMW) CK polypeptides in routinely processed primary lung carcinomas and lung metastases of diverse origin. As expected, immunohistochemical investigation gave no clear-cut results, but, with statistical analysis, lung adenocarcinomas could be separated from metastatic adenocarcinomas using CK 5 and 18 and HMW CK (specificity 92.5%, sensitivity 62.5%). The different origin of the metastases could often be detected using CK 18 and CK 20. Lung clear cell carcinomas and large cell carcinomas with clear cell areas could be distinguished from metastatic renal clear cell carcinomas by the CK 7 staining reaction. Squamous cell carcinomas of the lung and metastatic squamous cell carcinomas of the larynx, pharynx and oesophagus could not reliably be separated in part due to the few number of cases available. CK polypeptide typing is thus an additional aid in the differential diagnosis of lung carcinomas versus carcinomas metastatic to the lung.

Clear-Cell differentiation and lymphatic invasion, but not the revised TNM classification, predict lymph node metastases in pT1 penile cancer: A clinicopathologic study of 76 patients from a low incidence area

OBJECTIVE Prediction of lymph node (LN) metastases in penile invasive cancer relies on clinical features and histologic characteristics of the primary tumor. Correct prediction, however, is difficult, as only 50% patients undergoing lymphadenectomies will have LN metastases. In 2009, the tumor, nodes, metastases (TNM) classification for staging of early penile cancers was revised. We tested the predictive accuracy of the revised TNM classification in a low incidence area for penile carcinoma. MATERIALS AND METHODS The presence of LN metastases in 76 men with pT1 penile cancers was correlated with the 2009 TNM subclassification, which is based on a combined evaluation of tumor grade and lymphatic invasion, but also with individual parameters, such as histologic grade, lymphatic invasion, perineural invasion, invasion depth, growth pattern and human papilloma virus (HPV) status. RESULTS 76pT1 penile cancers were reclassified into 31pT1a squamous cell carcinomas (SCC) and 45pT1b (41 SCC; 4 clear-cell carcinomas); 12/22 men (55%; 8 SCC, 4 clear-cell carcinomas) undergoing lymphadenectomy for enlarged inguinal lymph nodes had metastases, 54 patients without enlarged LN and lymphadenectomies had no LN metastases during follow-up of median 47 months. Statistically, clear cell differentiation of the primary carcinoma was highly associated with metastases (100% clear-cell carcinomas vs. 11% SCC) and poor survival (50% vs. 5.5%). Among conventional SCC, only lymphatic invasion showed a highly significant association with metastases with 100% specificity. The 2009 TNM classification, tumor grade alone, perineural invasion, growth pattern, invasion depth or HPV status could not predict LN status. Lymphadenectomy for enlarged LN resulted in 100% sensitivity and 42% predictive probability for identifying metastases and a 16% false positive rate. Statistically, survival correlated significantly with clear-cell differentiation and with lymphatic invasion in both clear-cell carcinomas and conventional SCC. CONCLUSIONS Penile clear-cell carcinomas are more aggressive cancers than SCC. Our observation suggests a benefit of a prophylactic lymphadenectomy for patients with clear-cell carcinomas. Among conventional SCC, only lymphatic invasion predicted LN metastases. Neither tumor grade alone nor perineural invasion, growth pattern, depth of invasion, and subgrouping according to the revised TNM classification correlated with metastases. Clinical evaluation of the LN status was superior to histologic risk stratification.