Genetic and Epigenetic Characteristics in Isolated Pancreatic Metastases of Clear-Cell Renal Cell Carcinoma.

Isolated pancreatic metastases of renal cell carcinoma (IsPMRCC) are a rare manifestation of metastatic, clear-cell renal cell carcinoma (RCC) in which distant metastases occur exclusively in the pancreas. In addition to the main symptom of the isolated occurrence of pancreatic metastases, the entity surprises with additional clinical peculiarities: (a) the unusually long interval of about 9 years between the primary RCC and the onset of pancreatic metastases; (b) multiple pancreatic metastases occurring in 36% of cases; (c) favourable treatment outcomes with a 75% 5-year survival rate; and (d) volume and growth-rate dependent risk factors generally accepted to be relevant for overall survival in metastatic surgery are insignificant in isPMRCC. The genetic and epigenetic causes of exclusive pancreatic involvement have not yet been investigated and are currently unknown. Conversely, according to the few available data in the literature, the following genetic and epigenetic peculiarities can already be identified as the cause of the protracted course: 1. high genetic stability of the tumour cell clones in both the primary tumour and the pancreatic metastases; 2. a low frequency of copy number variants associated with aggressiveness, such as 9p, 14q and 4q loss; 3. in the chromatin-modifying genes, a decreased rate of PAB1 (3%) and an increased rate of PBRM1 (77%) defects are seen, a profile associated with a favourable course; 4. an increased incidence of KDM5C mutations, which, in common with increased PBRM1 alterations, is also associated with a favourable outcome; and 5. angiogenetic biomarkers are increased in tumour tissue, while inflammatory biomarkers are decreased, which explains the good response to TKI therapy and lack of sensitivity to IT.

The Effect of Induction Chemotherapy with VEGF Inhibition on Tumor Response in Synchronously Metastasized Potentially Resectable Colorectal Cancer.

(1) Background: The pathological tumor response of the primary tumor to induction chemotherapy in synchronously metastasized colorectal cancer (mCRC) patients has not been investigated. The aim of this study was to compare patients treated with induction chemotherapy combined with vascular endothelial growth factor (VEGF) or with epidermal growth factor receptor (EGFR) antibodies. (2) Methods: We present a retrospective analysis, where we included 60 consecutive patients with potentially resectable synchronous mCRC who received induction chemotherapy combined with either VEGF or EGFR antibodies. The primary endpoint of this study was the regression of the primary tumor, which was assessed by the application of the histological regression score according to Rödel. The secondary endpoints were recurrence-free survival (RFS) and overall survival (OS). (3) Results: A significantly better pathological response and a longer RFS for patients treated with the VEGF antibody therapy compared to those treated with the EGFR antibodies was demonstrated (p = 0.005 for the primary tumor and log-rank = 0.047 for RFS). The overall survival did not differ. The trial was registered with clinicaltrial.gov, number NCT05172635. (4) Conclusion: Induction chemotherapy combined with a VEGF antibody revealed a better pathological response of the primary tumor, leading to a better RFS compared to that with EGFR therapy; this has clinical relevance in patients with potentially resectable synchronously mCRC.

Isolated Pancreatic Metastases of Renal Cell Carcinoma-Clinical Particularities and Seed and Soil Hypothesis.

A meta-analysis of 1470 isolated pancreatic metastases of renal cell carcinoma revealed, that, in addition to the unusual exclusive occurrence of pancreatic metastases and the favourable treatment results, the isPMRCC is characterised by further peculiarities of the clinical course: The lack of prognostic significance of volume and growth rate dependent risk factors and the independence of treatment results from standard or local resections. As an explanation for all these peculiarities, according to today's knowledge, a strong acting seed and soil mechanism can serve, which allows embolized tumour cells to grow to metastases only in the pancreas, and prevents them definitively or for years in all other organs. The good prognosis affects not only isolated PM, but also multi-organ metastases of the RCC, in which the additional occurrence of PM is also associated with a better prognosis. Genetic studies revealed specific changes in cases of PM of RCC: Lack of loss of 9p21.3 and 14q31.2, which are otherwise specific gene mutations at the onset of generalization, a low weight genome instability index, i.e., high genetic stability, and a low rate of PAB1 and a high rate of BPRM1 alterations, which signal a more favourable course. The cause of pancreatic organotropism in isPMRCC is still unclear, so only those factors that have been identified as promoting organotropism in other, more frequent tumour entities can be presented: Formation of the pre-metastatic niche, chemokine receptor-ligand mechanism, ability to metabolic adaptation, and immune surveillance.

Isolated Pancreatic Metastases of Renal Cell Cancer: Genetics and Epigenetics of an Unusual Tumour Entity.

Isolated pancreatic metastases of renal cell carcinoma (isPMRCC) are a rare manifestation of metastatic renal cell carcinoma (mRCC) characterized by two peculiarities: (1). The definite or at least long-term exclusive occurrence of metastases in the pancreas and (2). an unusual low tumour aggressiveness with slow tumour progression and consecutive, good treatment results. According to current knowledge, the exclusive occurrence of pancreatic metastases is due to a highly specific and highly selective seed and soil mechanism, which does not allow metastases settlement outside the pancreas, and whose detailed genetic/epigenetic causes are not yet elucidated. Recent studies have shed light on some of the pathways involved for the protracted course of the disease and highlighted a special genetic profile (lack of loss of 9p, lower weight genome instability index, low frequency of BAP1 alterations, and a high frequency of PBRM1 loss), which deviates from the conventional mRCC profile. Finally, the question of the reasons for the long-term relative genetic stability of the involved cell clones, which is an essential prerequisite for a favourable prognosis, remains unanswered.

Immunological Aspects of AXL/GAS-6 in the Context of Human Liver Regeneration.

AXL and its corresponding ligand growth arrest-specific 6 (GAS-6) are critically involved in hepatic immunomodulation and regenerative processes. Pleiotropic inhibitory effects on innate inflammatory responses might essentially involve the shift of macrophage phenotype from a pro-inflammatory M1 to an anti-inflammatory M2. We aimed to assess the relevance of the AXL/GAS-6-pathway in human liver regeneration and, consequently, its association with clinical outcome after hepatic resection. Soluble AXL (sAXL) and GAS-6 levels were analyzed at preoperative and postoperative stages in 154 patients undergoing partial hepatectomy and correlated with clinical outcome. Perioperative dynamics of interleukin (IL)-6, soluble tyrosine-protein kinase MER (sMerTK), soluble CD163 (sCD163), and cytokeratin (CK) 18 were assessed to reflect pathophysiological processes. Preoperatively elevated sAXL and GAS-6 levels predicted postoperative liver dysfunction (area under the curve = 0.721 and 0.722; P < 0.005) and worse clinical outcome. These patients failed to respond with an immediate increase of sAXL and GAS-6 upon induction of liver regeneration. Abolished AXL pathway response resulted in a restricted increase of sCD163, suggesting a disrupted phenotypical switch to regeneratory M2 macrophages. No association with sMerTK was observed. Concomitantly, a distinct association of IL-6 levels with an absent increase of AXL/GAS-6 signaling indicated pronounced postoperative inflammation. This was further supported by increased intrahepatic secondary necrosis as reflected by CK18M65. sAXL and GAS-6 represent not only potent and easily accessible preoperative biomarkers for the postoperative outcome but also AXL/GAS-6 signaling might be of critical relevance in human liver regeneration. Refractory AXL/GAS-6 signaling, due to chronic overactivation/stimulation in the context of underlying liver disease, appears to abolish their immediate release following induction of liver regeneration, causing overwhelming immune activation, presumably via intrahepatic immune regulation.

Tumour Evolution and Seed and Soil Mechanism in Pancreatic Metastases of Renal Cell Carcinoma.

In metastatic renal cell carcinoma, pancreatic metastases can appear in two clinical manifestations: (a) very rarely as isolated pancreatic metastases and (b) in the context with multi-organ metastatic disease. Both courses are characterised by rare, unusual clinical features. For isolated pancreatic metastases, the literature shows no effect on survival in all 11 publications that examined the effect of singular versus multiple pancreatic metastases; a lack of effect on survival time was also present in all 8 studies on pancreatic metastases size, in 7 of 8 studies on the influence of disease-free interval (DFI), and in 6 of 7 studies on the influence of synchronous versus metachronous metastases. In multi-organ site metastases observations, on the other hand, all five available references showed significantly better results in patients with concurrent pancreatic metastases compared to those without pancreatic metastases, although the total number of affected organs in the pancreatic metastases cohort was larger. Tumour volume-dependent risk factors thus remain surprisingly ineffective in both groups, which contradicts the usual behaviour of solid tumours. The reasons for this unusual behaviour and possible relations to tumour evolution and the hypothesis of an influence of a seed and soil mechanism in the occurrence of pancreatic metastases in metastatic renal cell carcinoma are discussed.

Impact of Fibroblast-Derived SPARC on Invasiveness of Colorectal Cancer Cells.

Secreted protein acidic and rich in cysteine (SPARC) is a matricellular protein modulating cell-matrix interactions and was found up-regulated in tumor stroma. To explore the effect of high stromal SPARC on colorectal cancer (CRC) cell behavior and clinical outcome, this study determined SPARC expression in patients suffering from stage II and III CRC using a publicly available mRNA data set and immunohistochemistry of tissue microarray sections. Moreover, in vitro co-culture models using CRC cell lines together with colon-associated fibroblasts were established to determine the effect of fibroblast-derived SPARC on cancer cells. In 466 patient samples, high SPARC mRNA was associated with a shorter disease-free survival. In 99 patients of the tissue microarray cohort, high stromal SPARC in the primary tumor was an independent predictor of shorter survival in patients with relapse (27 cases; HR = 4574, p = 0.004). In CRC cell lines, SPARC suppressed phosphorylation of focal adhesion kinase and stimulated cell migration. Colon-associated fibroblasts increased migration velocity by 30% and doubled track-length in SPARC-dependent manner. In a 3D co-culture system, fibroblast-derived SPARC enhanced tumor cell invasion. Taken together, stromal SPARC had a pro-metastatic impact in vitro and was a characteristic of aggressive tumors with poor prognosis in CRC patients.

Epithelial splicing regulatory protein 1 and 2 paralogues correlate with splice signatures and favorable outcome in human colorectal cancer.

ESRPs are master splice regulators implicated in alternative mRNA splicing programs important for epithelial-mesenchymal transition (EMT) and tumor progression. ESRP1 was identified in some tumors as good or worse predictor of outcome, but in colorectal cancer (CRC) the prognostic value of ESRPs and relation with mesenchymal splice variants is not clear. Here, we studied 68 CRC cases, compared tissue expression of ESRPs with clinical data and with EMT gene splice patterns of conditional CRC cells with deficient ESRP1 expression.Around 72% of patients showed global decreased transcript expression of both ESRPs in tumor as compared to matched non-neoplastic colorectal epithelium. Reduction of ESRP1 in tumor cells was evaluated by immunohistochemistry, associated with microsatellite stability and switch to mesenchymal splice signatures of FGFRs, CD44, ENAH and CTNND1(p120-catenin). Expression of ESRPs was significantly associated with favorable overall survival (log-rank test, P=0.0186 and 0.0408), better than prognostic stratification by tumor staging; and for ESRP1 confirmed with second TCGA cohort (log-rank test, P=0.0435). Prognostic value is independent of the pathological stage and microsatellite instability (ESRP1: HR=0.36, 95%CI 0.15-0.91, P=0.032; ESRP2: HR=0.23, 95%CI 0.08-0.65, P=0.006).Our study supports the role of ESRP1 as tumor suppressor and strongly suggests that ESRPs are candidate markers for early detection, diagnosis, and prognosis of CRC.

Tumor and Patient Characteristics of Individuals with Mismatch Repair Deficient Colorectal Cancer.

AIMS: To investigate tumor and patient characteristics of individuals with mismatch repair (MMR)-deficient colorectal carcinomas. METHODS: We immunhistochemically investigated tissue samples of 307 consecutive patients with colorectal cancer for defects in DNA MMR proteins (hMLH1, hMSH2, hMSH6, hPMS2) and those with mutations further for microsatellite instability (MSI) and BRAF V600E mutations. RESULTS: 32/308 (10.4%) tumors showed MMR deficiency. Seventy five percent (n = 24) had loss of hMLH1 and hPMS2 expression, 3% (n = 1) of hPMS2 alone, 18.8% (n = 6) of hMSH6 and hMSH2, 3% (n = 1) of hMSH2 alone. All MMR-deficient tumors showed high MSI. These tumors occurred preferably in the right-sided colon, in women and showed specific histological features. We obtained the family history of 18/32 patients; 2 (11.1%) met Amsterdam Criteria, 5 (27.8%) Bethesda Guidelines and 6 (33.3%) revised Bethesda Guidelines. BRAF V600E mutations were found in 16 (67%) of hMLH1 and none of the hMSH2 deficient tumors. CONCLUSION: We suggest using immunhistochemical testing of tumor tissues with subsequent MSI analysis, which may be justified as a screening method for MMR deficiency in colorectal cancer, since it identifies patients with possibly hereditary defects and unalike response to chemotherapy.

Differential effects of polymorphic alleles of FGF receptor 4 on colon cancer growth and metastasis.

A gly(388)arg polymorphism (rs351855) in the transmembrane domain of the fibroblast growth factor receptor (FGFR4) is associated with increased risk, staging, and metastasis in several different types of cancer. To specifically assess the impact of the polymorphic FGFR4 in colorectal cancer (CRC), we engineered CRC cell lines with distinct endogenous expression patterns to overexpress either the FGFR4(gly) or FGFR4(arg) alleles. The biologic analyses revealed an oncogenic importance for both polymorphic alleles, but FGFR4(gly) was the stronger inducer of tumor growth, whereas FGFR4(arg) was the stronger inducer of migration. An evaluation of clinical specimens revealed that FGFR4 was upregulated in 20/71 patients independent of gly(388)arg status. There was no correlation between the presence of an FGFR4(arg) allele and CRC or polyp risk in 3,471 participants of the CORSA study. However, among 182 patients with CRC, FGFR4(arg)-carriers had a fivefold higher risk of tumors that were stage II or greater. Together, our results established that both allelic forms of FGFR4 exert an oncogenic impact and may serve equally well as therapeutic targets in CRC. One important implication of our findings is that FGFR4(arg)-carriers are at a higher risk for more aggressive tumors and therefore may profit from early detection measures.

TNM stage and grade in predicting the prognosis of operated, non-functioning neuroendocrine carcinoma of the pancreas--a single-institution experience.

OBJECTIVE: To evaluate the prognostic significance of TNM and grading categories in curatively resected non-functioning neuroendocrine pancreatic carcinoma (nfnepC). METHOD: Eighteen nfnepC were retrospectively analyzed for differences in survival. RESULTS: (1) There was a correlation between pT (P = 0.026), respectively pM categories (P = 0.016) and survival. (2) G categories and length of survival were closely correlated (P = 0.0036). (3) Disease stages I-IV had a significant effect on survival (P = 0.051). (4) The WHO classification in well and poorly differentiated carcinomas proved to be the most conclusive predictive factor (P = 0.0009). (5) Subgroups with significantly different prognoses determined by histological grade were present within disease stage II. CONCLUSIONS: The retrospective analysis showed a good correlation between survival and pT, pM, tumor stage, G categories, and WHO classification in well and poorly differentiated carcinomas. Including histological differentiation in the staging system or carrying it out separately in well and poorly differentiated carcinomas, could enhance the predictive potential of TNM-based disease stages.

Melatonin receptors, melatonin metabolizing enzymes and cyclin D1 in human breast cancer.

BACKGROUND: Melatonin suppresses breast cancer cell proliferation by inhibiting the upregulation of estrogen-induced cyclin D1 via its G-protein-coupled receptor MT1. Additionally, melatonin stimulates the expression of the estrogen sulfotransferase, SULT1E1. However, metabolism of melatonin via 6-hydroxylation by CYP1A1/1A2 and subsequent sulfonation by SULT1A1/1A3 decreases its intracellular concentration. This could have a negative impact on its oncostatic action in breast cancer. PATIENTS AND METHODS: In this pilot study, we performed immunohistochemical (IHC) analysis of MT1 and cyclin D1 in breast cancer specimens from 33 patients. Also, we investigated the expression of CYP1A1/1A2, SULT1A1/1A3/1E1,and cyclin D1 in cancer (CANC) and adjacent non-cancer (NCANC) specimens from 10 representative breast cancer patients using quantitative real-time reverse transcription polymerase chain reaction. RESULTS: CYP1A1-mRNA-expression was found only in three CANC and in one NCANC. CYP1A2 mRNA was below the detection limit in all patients. SULT1A1 was observed only in two of the 10 CANC and one of the 10 NCANC specimens. But, all 10 CANC and NCANC samples showed high SULT1A3 levels. Cyclin D1 mRNA levels were found in all 10 CANC and NCANC specimens. Furthermore, IHC-staining of cyclin D1 was observed in 27 of 33 CANC and correlated positively with estrogen receptor positivity (p = 0.015). CONCLUSION: The low or even absent expression of CYP1A1 or CYP1A2 in breast cancer specimens suggested that melatonin might be involved in cell cycle arrest.

Clinical and economic aspects of KRAS mutational status as predictor for epidermal growth factor receptor inhibitor therapy in metastatic colorectal cancer patients.

Treatment of metastasized colorectal cancer (mCRC) patients with anti-epidermal growth factor receptor (EGFR)-directed monoclonal antibodies is driven by the results of the KRAS mutational status (wild type [WT]/mutated [MUT]). To find out as to what extent the treatment selection based on the KRAS status had impact on overall costs, a retrospective analysis was performed. Of 73 mCRC patients 31.5% were MUT carriers. Costs of EGFR inhibitor treatment for WT patients were significantly higher compared to those for patients with MUT (p = 0.005). Higher treatment costs in WT carriers reflect a significantly higher number of treatment cycles (p = 0.012) in this cohort of patients. Savings of drug costs minus the costs for the determination of KRAS status accounted for EUR 779.42 (SD ±336.28) per patient per cycle. The routine use of KRAS screening is a cost-effective strategy. Costs of unnecessary monoclonal EGFR inhibitor treatment can be saved in MUT patients.

Neuromuscular electrical stimulation reduces skeletal muscle protein degradation and stimulates insulin-like growth factors in an age- and current-dependent manner: a randomized, controlled clinical trial in major abdominal surgical patients.

OBJECTIVE: To investigate the effect of neuromuscular electrical stimulation (NMES) on skeletal muscle metabolism after major abdominal surgery. SUMMARY BACKGROUND DATA: Protein catabolism associated with surgical interventions leads to reduced muscle strength, increased clinical complications and prolonged convalescence. Immobilization is suggested as a major stimulus for muscle wasting. This study investigates the potency of NMES on skeletal muscle growth factors and degradation processes in surgical patients. METHODS: This observer blind study included 26 patients after major abdominal surgery mainly due to cancer aged 60 +/- 10 years. Starting on the first postoperative day, 1 randomly assigned thigh of each patient was treated on 4 consecutive days with NMES, whereas the other leg was used as sham-stimulated control. Thereafter, muscle biopsies from both legs were performed. Differences in mRNA level, protein expression, and enzyme activity between legs were analyzed by cross-over analysis of variance (Clinical Trial Registration Number: NCT00635440). RESULTS: NMES significantly increased total RNA content and total sarcoplasmatic protein content. NMES significantly reduced ubiquitin-conjugated sarcoplasmatic proteins and proteasome activity. The mechano growth factor mRNA level correlated positively with the applied current and negatively with the body mass index of the patients. The increase in insulin like growth factor-1Ea mRNA after NMES correlated negatively with the age of the patients. CONCLUSIONS: This study shows that NMES significantly increases total RNA content and reduces protein degradation in postoperative patients. Moreover, the induction of growth factors by NMES reveals dependency on body mass index, age, and applied current. We conclude that NMES is a useful clinical tool to reduce protein catabolism in postoperative patients.

Pancreatic stellate/myofibroblast cells express G-protein-coupled melatonin receptor 1.

In chronic pancreatitis and pancreatic cancer, progressive fibrosis with the accumulation of extracellular matrix occurs. The main extracellular matrix-producing cell types are retinoid-storing pancreatic stellate cells (PSCs) of mesenchymal origin. Similar to liver stellate cells, quiescent PSCs undergo activation and acquire a myofibroblast-like phenotype in response to pro-fibrogenic mediators (reactive oxygen species, cytokines and toxic metabolites). Activated PSCs differ in their differentiation stage and are characterized by the expression of glial fibrillary-acidic protein, alpha-smooth muscle actin, and nestin. As G-protein-coupled receptors were described to regulate PSC differentiation, we investigated tissue samples from patients with pancreatitis and ductal pancreatic adenocarcinoma for the expression of G-protein-coupled melatonin receptors MT1 and MT2 by double immunofluorescence staining. We show that MT1, but not MT2, is occasionally expressed in PSCs in normal tissue, while in the diseased tissue MT1 is found at high rates in activated PSCs at all stages, and, additionally, in ductal epithelial cells. It is speculated that MT1 activation by its ligand melatonin regulates proliferation and differentiation of PSCs. Prevention of myofibroblast formation by MT1 activation could explain favourable effects of the pineal hormone melatonin on the outcome of pancreatic fibrosis in animal models.

Cell cycle dysregulation influences survival in high risk breast cancer patients.

BACKGROUND: Cell cycle progression is regulated by cyclin dependent kinases (cdk) and cdk inhibitors. Recent immunohistological studies suggested that dysregulation of cyclin A, cyclin D, cyclin E, p16(ink4), p21(waf1/cip1), and p27(kip1) are of prognostic value in patients with breast cancer. Our study represents the first comprehensive immunohistochemical cell cycle marker analysis for cdc25A, cyclin A, cyclin D, cyclin E, p16(ink4), p21(waf1/cip1), p27(kip1), and pRb in tumor tissue and adjacent benign breast tissue from 69 primarily untreated breast cancer patients. METHODS: Immunhistochemistry using primary monoclonal antibodies to detect cdc 25A, cyclin A, cyclin D, cyclin E, p16(ink4), p21(waf1/cip1), p27(kip1), and pRb has been performed. RESULTS: Sixty-nine patients with untreated, invasive breast cancer (n = 69) were divided into a low/ intermediate and a high risk group according to the St. Gallen 2005 consensus conference. High risk patients (n = 22) had a significantly (p = 0.003) shorter mean and median survival (282.85 weeks; 383.0 weeks, respectively) than low/intermediate risk patients (375.41 weeks; not reached yet, respectively). A subgroup of high risk breast cancer patients characterized in addition by overexpression of cdc25A, cyclin A, cyclin E, p16(ink4a), and p27(kip1) experienced a shortened mean survival of 222.03, 235.71, 257.25, 239.18, and 261.94 weeks, respectively. Regarding benign breast tissue adjacent to breast cancer tissue, 59.4% of the patients investigated overexpressed cdc25A, 23.2% overexpressed pRb, and 63.2% exerted dysregulation of p27(kip1) while they proved to be negative for immunohistochemical staining regarding all other markers tested. CONCLUSION: The immunohistological analyses of cdc25A, cyclin A, cyclin E, p16(ink4a), and p27(kip1) have the potential for further refining the risk assessment in patients with untreated breast cancer who belong to the high risk category defined according to the St. Gallen 2005 consensus conference. These cell cycle markers define a subgroup of high risk patients with even higher risk of metastazation and shortened survival. For confirmation a prospective study using standardized laboratory procedures in a larger population is needed.

Expression of estrogen-metabolizing enzymes and estrogen receptors in cholelithiasis gallbladder.

BACKGROUND: Estrogen exposure is a risk factor for gallstone disease (cholelithiasis), which often leads to chronic inflammation (cholecystitis). Studies in various estrogen-sensitive tissues showed that key enzymes involved in the inactivation and activation of estrogens as well as expression of estrogen receptors alpha and beta determine the amount of active estrogen. In estrogen-sensitive tissues, e.g. the female breast, estrone sulfate (E1S), present at high concentrations in the circulation, is converted into the biologically active estrone (E1) by steroid sulfatase (STS) and again reverted into E1S by estrogen sulfotransferase (SULT1E1) providing a local estrogen storage. AIMS: To assess whether this might also apply for gallbladder epithelia, we determined expression of these two enzymes and of ERalpha and ERbeta in 15 cholelithiasis specimens from tissues with/or without inflammation. METHODS: Quantitative (Real-time) PCR and immunofluorescence were used as methods. RESULTS: We demonstrate mRNA expression of SULT1E1, STS, and ERalpha in all specimens with mean enrichment of 3.53- vs. 1.72-fold (n.s.), 3.5- vs. 0.91-fold (n.s.), and 3.04- vs. 1.6-fold (n.s.) in the inflammatory and non-inflammatory groups, respectively. Although high expression levels were seen in many specimens (means 4.88-fold vs. 5.77-fold), ERbeta mRNA was below the detection limit in two specimens from cholecystitis patients. To further investigate this varying expression pattern of ERbeta, immunohistological studies were performed, which indeed showed low expression levels of ERbeta in the damaged mucosa, while in specimens with well preserved mucosa, high ERbeta levels were seen in the cytosol and in the nucleus. CONCLUSION: The data show expression of an estrogen network of activating STS and inactivating SULT1E1. Together with ERalpha and ERbeta, these enzymes could regulate estrogen concentrations in human gallbladder.

FGF18 in colorectal tumour cells: autocrine and paracrine effects.

Fibroblast growth factors (FGFs) and their high-affinity receptors contribute to the autocrine growth stimulation in several human malignancies. Here, we describe that FGF18 expression is up-regulated in 34/38 colorectal tumours and is progressively enhanced during colon carcinogenesis reaching very high levels in carcinoma. Moreover, our data suggest that FGF18 affects both tumour cells and tumour microenvironment in a pro-tumorigenic and pro-metastatic way. Addition of recombinant FGF18 to the culture media of slowly growing colorectal tumour cell lines LT97 and Caco-2 stimulated proliferation. Phosphorylation of externally regulated kinase 1/2 and S6 was increased already 5 min after growth factor addition. SW480 cells, endogenously producing large amounts of FGF18, were not affected in this setting, but recombinant FGF18 supported tumour cell survival under conditions of serum starvation. Down-modulation of endogenous FGF18 production by small interference RNA (siRNA) significantly reduced clonogenicity of SW480 cells and restored sensitivity to exogenous FGF18. With respect to the tumour microenvironment, both recombinant and tumour-derived FGF18 stimulated growth of colon-associated fibroblasts at 0.1 ng/ml and migration at 10 ng/ml. In addition, recombinant FGF18 (10 ng/ml) induced tube formation in human umbilical vein endothelial cells. siRNA knock down demonstrated that tube-forming activity of colon cancer cell supernatants depended to a large part on tumour cell-derived FGF18. In summary, this study demonstrates that FGF18 is almost generally over-expressed in colon cancer and exerts pro-tumorigenic effects both in the epithelial and the stromal compartments by stimulating growth and survival of tumour cells, migration of fibroblasts and neovascularization. Together, these data strongly support an oncogenic role of FGF18 in colorectal cancer.