MMP19 is upregulated during melanoma progression and increases invasion of melanoma cells

During the progression of cutaneous melanomas, matrix metalloproteinases (MMPs) facilitate the tumour cells to traverse the basement membrane and invade the dermis. In this study, we analysed the expression of MMP19 in the course of melanoma progression. Although MMP19 was absent in melanocytes and melanoma cells of early stages of melanoma development, its expression was strongly upregulated in the neighbouring keratinocytes that may facilitate the vertical outgrowth of melanoma cells. In contrast to early stages, MMP19 was upregulated during the vertical growth phase of melanoma and in metastases. The upregulation of MMP19 in melanoma of Clark levels IV and V correlates with that of MMP2 and also simultaneously with ceased expression of E-cadherin. To reveal whether MMP19 facilitates the invasion of melanomas, we examined adhesion and migratory capacity of selected melanoma cell lines. Melanoma cell lines with low expression of MMP19 exhibited increased adhesion to various substrates and lower migration in comparison with the cell line with higher expression of MMP19. Moreover, ectopic expression of MMP19 could restore the migratory capacity of melanoma cells with low endogenous level of MMP19. These results suggest that the increase of MMP19 expression hallmarks the progression of cutaneous melanoma and might augment melanoma growth by promoting the invasion of tumour cells.

Preponderance of cells with stem cell characteristics in metastasising mouse mammary tumours induced by deregulated EphB4 and ephrin-B2 expression

We have previously shown that EphB4 and ephrin-B2 are differentially expressed in the mammary gland and that their deregulated expression in the mammary epithelium of transgenic mice leads to perturbations of the mammary parenchyma and vasculature. In addition, overexpression of EphB4 and expression of a truncated ephrin-B2 mutant, capable of receptor stimulation but incapable of reverse signalling, confers a metastasising phenotype on NeuT initiated mouse mammary tumours. We have taken advantage of this transgenic tumour model to compare stem cell characteristics between the non-metastasising and metastasising mammary tumours. We analysed the expression of the proliferation attenuating p21(waf) gene, which was significantly increased in the metastasising tumours. Moreover, we compared the expression of CK-19, Sca-1, CD24 and CD49f as markers for progenitor cells exhibiting a decreasing differentiation grade. Sca-1 expressing cells were the earliest progenitors detected in the non-metastasising NeuT induced tumours. The metastasising NeuT/EphB4 tumours were enriched in CD24 expressing cells, whereas the metastasising NeuT/truncated ephrin-B2 tumours contained in addition significant amounts of CD49f expressing cells. The same cell populations were also enriched in mammary glands of single transgenic MMTV-EphB4 and MMTV-truncated ephrin-B2 females indicating that deregulated EphB4-ephrin-B2 signalling interferes with the homeostasis of the stem/progenitor cell pool before tumour formation is initiated. Since the same cell populations are enriched in the normal tissue, primary mammary tumours and metastases we conclude that these progenitor cells were the origin of tumour formation and that this change in the tumour origin has led to the acquisition of the metastatic tumour phenotype.

DW-MRI of the urogenital tract: applications in oncology

Diffusion-weighted magnetic resonance imaging (DW-MRI) appears to hold promise as a non-invasive imaging modality in the detection of early microstructural and functional changes of different organs. DW-MRI is an imaging technique with a high sensitivity for the detection of a large variety of diseases in the urogenital tract. In kidneys, DW-MRI has shown promise for the characterization of solid lesions. Also in focal T1 hyperintense lesions DW-MRI was able to differentiate hemorrhagic cysts from tumours according to the lower apparent diffusion coefficient (ADC) values reported for renal cell carcinomas. Promising results were also published for the detection of prostate cancer. DW-MRI applied in addition to conventional T2-weighted imaging has been found to improve tumour detection. On a 3 T magnetic resonance unit ADC values were reported to be lower for tumours compared with the normal-appearing peripheral zone. The combined approach of T2-weighted imaging and DW-MRI also showed promising results for the detection of recurrent tumour in patients after radiation therapy. DW-MRI may improve the performance of conventional T2-weighted and contrast-enhanced MRI in the preoperative work-up of bladder cancer, as it may help in distinguishing superficial from muscle invasive bladder cancer, which is critical for patient management. Another challenging application of DW-MRI in the urogenital tract is the detection of pelvic lymph node metastases. As the ADC is generally reduced in malignant tumours and increased under inflammatory conditions, reduced ADC values were expected in patients with lymph node metastases.

Risk profiles and penetrance estimations in multiple endocrine neoplasia type 2A caused by germline RET mutations located in exon 10

Multiple endocrine neoplasia type 2 is characterized by germline mutations in RET. For exon 10, comprehensive molecular and corresponding phenotypic data are scarce. The International RET Exon 10 Consortium, comprising 27 centers from 15 countries, analyzed patients with RET exon 10 mutations for clinical-risk profiles. Presentation, age-dependent penetrance, and stage at presentation of medullary thyroid carcinoma (MTC), pheochromocytoma, and hyperparathyroidism were studied. A total of 340 subjects from 103 families, age 4-86, were registered. There were 21 distinct single nucleotide germline mutations located in codons 609 (45 subjects), 611 (50), 618 (94), and 620 (151). MTC was present in 263 registrants, pheochromocytoma in 54, and hyperparathyroidism in 8 subjects. Of the patients with MTC, 53% were detected when asymptomatic, and among those with pheochromocytoma, 54%. Penetrance for MTC was 4% by age 10, 25% by 25, and 80% by 50. Codon-associated penetrance by age 50 ranged from 60% (codon 611) to 86% (620). More advanced stage and increasing risk of metastases correlated with mutation in codon position (609?620) near the juxtamembrane domain. Our data provide rigorous bases for timing of premorbid diagnosis and personalized treatment/prophylactic procedure decisions depending on specific RET exon 10 codons affected.

Immunophenotyping analysis in invasive micropapillary carcinoma of the breast: Role of CD24 and CD44 isoforms expression

We analyzed immunohistochemically the expression of CD24 and spliced variants of CD44v5 and v9 in invasive micropapillary carcinoma (IMPC) of the breast that is a rather aggressive tumor characterized by alteration of cells adhesion molecules, early lymph node metastases and poor prognosis. We analyzed 31 high-grade IMPCs and compared their expression to 22 high grade (G3) invasive ductal carcinomas of the breast (IDCs). We found a higher expression of CD24 in high-grade IMPCs with a peculiar inverted apical localization, compared to IDCs, showing a strong cytoplasmic staining; normal breast tissue resulted completely negative. IMPCs showed reduced expression of CD44v5 and CD44v9 compared with IDCs, but without a statistical significant difference. This study demonstrated that IMPC represents a distinct entity of breast carcinoma with high expression of CD24 with a typical inverted apical membrane pattern and reduction of CD44 isoforms v5 and v9, compared to IDCs. These features could explain the high lymph-vascular invasion propensity and higher metastatic capability of these tumors and could be a useful tool for a future targeted therapy.

High CD10 expression predicts favorable outcome in surgically treated lymph node-positive bladder cancer patients

CD10 predicts survival in different cancers. The prognostic significance in bladder cancer still has to be documented. One hundred fifty lymph node-positive bladder cancer patients were treated by cystectomy and standardized pelvic lymphadenectomy in curative intent. CD10 expression was evaluated in tissue microarrays (TMAs) constructed from histopathological normal urothelium, primary tumor (tumor center and invasion front), and corresponding lymph node metastases and correlated with tumor characteristics (stage, extracapsular extension, number, and total diameter of metastases) and survival. CD10 expression was successively lost from normal urothelium to primary tumor to metastases (P < .05) and decreased from the tumor center to the invasion front (P < .002). High CD10 expression in tumor center or invasion front (P < .05) but not in the metastases predicted favorable outcome; the prognostic information in the tumor center was independent from tumor stage and lymph node parameters. High CD10 expression level was not associated with specific tumor characteristics. A well-defined sampling strategy for TMAs allows detection of specific biomarker expression patterns and may generate prognostic information inherent in particular tumor areas. The favorable outcome in bladder cancer patients with high CD10 expression might suggest a tumor suppressive function of CD10.

MMP-2 and MMP-9 in lymph-node-positive bladder cancer

Matrix metalloproteinases (MMP), particularly MMP-2 and MMP-9, participate in tumour progression and metastasis in various cancers. Their significance in urothelial cancer of the bladder (UCB) is unclear. Expression analysis of MMP-2 and MMP-9 in tissue microarrays (TMA) constructed of corresponding samples from histopathological normal urothelium, tumour centre and invasion front of primary tumours and lymph-node (LN) metastases might help to elucidate their relevance in UCB.

Glycogen-rich pleomorphic xanthoastrocytoma with clear-cell features: confirmatory report of a rare variant with implications for differential diagnosis

Central nervous system space-occupying lesions with clear-cell features encompass a nosologically heterogeneous array, ranging from reactive histiocytic proliferations to neuroepithelial or meningothelial neoplasms of various grades and to metastases. In the face of such differential diagnostic breadth, recognizing cytoplasmic lucency as part of the morphological spectrum of some low grade gliomas will directly have an impact on patient care. We describe a prevailing clear-cell change in an epileptogenic left temporal pleomorphic xanthoastrocytoma surgically resected from a 36-year-old man. Mostly subarachnoid and focally calcified, the tumor was composed of fascicles of moderately atypical spindle cells with optically lucent cytoplasm that tended to intermingle with a desmoplastic mesh of reticulin fibers. Immunohistochemically, coexpression of S100 protein, vimentin, GFAP, and CD34 was noted. Conversely, neither punctate staining for EMA nor positivity for CD68 was seen. Mitotic activity was absent, and the MIB1 labeling index was 2-3% on average. Diastase-sensitive PAS-positive granula indicated clear-cell change to proceed from glycogen storage. Electron microscopy showed tumor cell cytoplasm to be largely obliterated by non-lysosomal-bound pools of glycogen, while hardly any fat vacuole was encountered. Neither ependymal-derived organelles nor annular lamellae suggesting oligodendroglial differentiation were detected. The latter differential diagnosis was further invalidated by lack of codeletion of chromosomal regions 1p36 and 19q13 on molecular genetic testing. By significantly interfering with pattern recognition as an implicit approach in histopathology, clear-cell change in pleomorphic xanthoastrocytoma is likely to suspend its status as a "classic", and to prompt more deductive differential diagnostic strategies to exclude look-alikes, especially clear-cell ependymoma and oligodendroglioma.

FOXA1 Promotes Tumor Progression in Prostate Cancer and Represents a Novel Hallmark of Castration-Resistant Prostate Cancer

Forkhead box protein A1 (FOXA1) modulates the transactivation of steroid hormone receptors and thus may influence tumor growth and hormone responsiveness in prostate cancer. We therefore investigated the correlation of FOXA1 expression with clinical parameters, prostate-specific antigen (PSA) relapse-free survival, and hormone receptor expression in a large cohort of prostate cancer patients at different disease stages. FOXA1 expression did not differ significantly between benign glands from the peripheral zone and primary peripheral zone prostate carcinomas. However, FOXA1 was overexpressed in metastases and particularly in castration-resistant cases, but was expressed at lower levels in both normal and neoplastic transitional zone tissues. FOXA1 levels correlated with higher pT stages and Gleason scores, as well as with androgen (AR) and estrogen receptor expression. Moreover, FOXA1 overexpression was associated with faster biochemical disease progression, which was pronounced in patients with low AR levels. Finally, siRNA-based knockdown of FOXA1 induced decreased cell proliferation and migration. Moreover, in vitro tumorigenicity was inducible by ARs only in the presence of FOXA1, substantiating a functional cooperation between FOXA1 and AR. In conclusion, FOXA1 expression is associated with tumor progression, dedifferentiation of prostate cancer cells, and poorer prognosis, as well as with cellular proliferation and migration and with AR signaling. These findings suggest FOXA1 overexpression as a novel mechanism inducing castration resistance in prostate cancer.

Enhanced activity of meprin-?, a pro-migratory and pro-angiogenic protease, in colorectal cancer

Meprin-α is a metalloprotease overexpressed in cancer cells, leading to the accumulation of this protease in a subset of colorectal tumors. The impact of increased meprin-α levels on tumor progression is not known. We investigated the effect of this protease on cell migration and angiogenesis in vitro and studied the expression of meprin-α mRNA, protein and proteolytic activity in primary tumors at progressive stages and in liver metastases of patients with colorectal cancer, as well as inhibitory activity towards meprin-α in sera of cancer patient as compared to healthy controls. We found that the hepatocyte growth factor (HGF)-induced migratory response of meprin-transfected epithelial cells was increased compared to wild-type cells in the presence of plasminogen, and that the angiogenic response in organ-cultured rat aortic explants was enhanced in the presence of exogenous human meprin-α. In patients, meprin-α mRNA was expressed in colonic adenomas, primary tumors UICC (International Union Against Cancer) stage I, II, III and IV, as well as in liver metastases. In contrast, the corresponding protein accumulated only in primary tumors and liver metastases, but not in adenomas. However, liver metastases lacked meprin-α activity despite increased expression of the corresponding protein, which correlated with inefficient zymogen activation. Sera from cancer patients exhibited reduced meprin-α inhibition compared to healthy controls. In conclusion, meprin-α activity is regulated differently in primary tumors and metastases, leading to high proteolytic activity in primary tumors and low activity in liver metastases. By virtue of its pro-migratory and pro-angiogenic activity, meprin-α may promote tumor progression in colorectal cancer.

Malignant pheochromocytomas and paragangliomas: a diagnostic challenge

Malignant pheochromocytomas (PCCs) and paragangliomas (PGLs) are rare disorders arising from the adrenal gland, from the glomera along parasympathetic nerves or from paraganglia along the sympathetic trunk. According to the WHO classification, malignancy of PCCs and PGLs is defined by the presence of metastases at non-chromaffin sites distant from that of the primary tumor and not by local invasion. The overall prognosis of metastasized PCCs/PGLs is poor. Surgery offers currently the only change of cure. Preferably, the discrimination between malignant and benign PCCs/PGLs should be made preoperatively.

Hormonally defined pancreatic and duodenal neuroendocrine tumors differ in their transcription factor signatures: expression of ISL1, PDX1, NGN3, and CDX2

We recently identified the transcription factor (TF) islet 1 gene product (ISL1) as a marker for well-differentiated pancreatic neuroendocrine tumors (P-NETs). In order to better understand the expression of the four TFs, ISL1, pancreatico-duodenal homeobox 1 gene product (PDX1), neurogenin 3 gene product (NGN3), and CDX-2 homeobox gene product (CDX2), that mainly govern the development and differentiation of the pancreas and duodenum, we studied their expression in hormonally defined P-NETs and duodenal (D-) NETs. Thirty-six P-NETs and 14 D-NETs were immunostained with antibodies against the four pancreatic hormones, gastrin, serotonin, calcitonin, ISL1, PDX1, NGN3, and CDX2. The TF expression pattern of each case was correlated with the tumor's hormonal profile. Insulin-positive NETs expressed only ISL1 (10/10) and PDX1 (9/10). Glucagon-positive tumors expressed ISL1 (7/7) and were almost negative for the other TFs. Gastrin-positive NETs, whether of duodenal or pancreatic origin, frequently expressed PDX1 (17/18), ISL1 (14/18), and NGN3 (14/18). CDX2 was mainly found in the gastrin-positive P-NETs (5/8) and rarely in the D-NETs (1/10). Somatostatin-positive NETs, whether duodenal or pancreatic in origin, expressed ISL1 (9/9), PDX1 (3/9), and NGN3 (3/9). The remaining tumors showed labeling for ISL1 in addition to NGN3. There was no association between a particular TF pattern and NET features such as grade, size, location, presence of metastases, and functional activity. We conclude from our data that there is a correlation between TF expression patterns and certain hormonally defined P-NET and D-NET types, suggesting that most of the tumor types originate from embryologically determined precursor cells. The observed TF signatures do not allow us to distinguish P-NETs from D-NETs.

Impact of CD39 and purinergic signalling on the growth and metastasis of colorectal cancer

Despite improvements in prevention and management of colorectal cancer (CRC), uncontrolled tumor growth with metastatic spread to distant organs remains an important clinical concern. Genetic deletion of CD39, the dominant vascular and immune cell ectonucleotidase, has been shown to delay tumor growth and blunt angiogenesis in mouse models of melanoma, lung and colonic malignancy. Here, we tested the influence of CD39 on CRC tumor progression and metastasis by investigating orthotopic transplanted and metastatic cancer models in wild-type BALB/c, human CD39 transgenic and CD39 deficient mice. We also investigated CD39 and P2 receptor expression patterns in human CRC biopsies. Murine CD39 was expressed by endothelium, stromal and mononuclear cells infiltrating the experimental MC-26 tumors. In the primary CRC model, volumes of tumors in the subserosa of the colon and/or rectum did not differ amongst the treatment groups at day 10, albeit these tumors rarely metastasized to the liver. In the dissemination model, MC-26 cell line-derived hepatic metastases grew significantly faster in CD39 over-expressing transgenics, when compared to CD39 deficient mice. Murine P2Y2 was significantly elevated at both mRNA and protein levels, within the larger liver metastases obtained from CD39 transgenic mice where changes in P2X7 levels were also noted. In clinical samples, lower levels of CD39 mRNA in malignant CRC tissues appeared associated with longer duration of survival and could be linked to less invasive tumors. The modulatory effects of CD39 on tumor dissemination and differential levels of CD39, P2Y2 and P2X7 expression in tumors suggest involvement of purinergic signalling in these processes. Our studies also suggest potential roles for purinergic-based therapies in clinical CRC.

The role of the BMP signaling antagonist noggin in the development of prostate cancer osteolytic bone metastasis

Members of the BMP and Wnt protein families play a relevant role in physiologic and pathologic bone turnover. Extracellular antagonists are crucial for the modulation of their activity. Lack of expression of the BMP antagonist noggin by osteoinductive, carcinoma-derived cell lines is a determinant of the osteoblast response induced by their bone metastases. In contrast, osteolytic, carcinoma-derived cell lines express noggin constitutively. We hypothesized that cancer cell-derived noggin may contribute to the pathogenesis of osteolytic bone metastasis of solid cancers by repressing bone formation. Intra-osseous xenografts of PC-3 prostate cancer cells induced osteolytic lesions characterized not only by enhanced osteoclast-mediated bone resorption, but also by decreased osteoblast-mediated bone formation. Therefore, in this model, uncoupling of the bone remodeling process contributes to osteolysis. Bone formation was preserved in the osteolytic lesions induced by noggin-silenced PC-3 cells, suggesting that cancer cell-derived noggin interferes with physiologic bone coupling. Furthermore, intra-osseous tumor growth of noggin-silenced PC-3 cells was limited, most probably as a result of the persisting osteoblast activity. This investigation provides new evidence for a model of osteolytic bone metastasis where constitutive secretion of noggin by cancer cells mediates inhibition of bone formation, thereby preventing repair of osteolytic lesions generated by an excess of osteoclast-mediated bone resorption. Therefore, noggin suppression may be a novel strategy for the treatment of osteolytic bone metastases.

Prognostic value of microvascular invasion in predicting the cancer specific survival and risk of metastatic disease in renal cell carcinoma: a multicenter investigation

While microvascular invasion is an accepted risk factor in various cancers, its prognostic role in renal cell carcinoma is still unclear. Therefore, a large multicenter study examining the experience of 5 international institutions was performed to evaluate the prognostic value of microvascular invasion in the occurrence of metastases and cancer specific survival.