Microenvironment-induced restoration of cohesive growth associated with focal activation of P-cadherin expression in lobular breast carcinoma metastatic to the colon.

Invasive lobular carcinoma (ILC) is a special breast cancer type characterized by noncohesive growth and E-cadherin loss. Focal activation of P-cadherin expression in tumor cells that are deficient for E-cadherin occurs in a subset of ILCs. Switching from an E-cadherin deficient to P-cadherin proficient status (EPS) partially restores cell-cell adhesion leading to the formation of cohesive tubular elements. It is unknown what conditions control EPS. Here, we report on EPS in ILC metastases in the large bowel. We reviewed endoscopic colon biopsies and colectomy specimens from a 52-year-old female (index patient) and of 18 additional patients (reference series) diagnosed with metastatic ILC in the colon. EPS was assessed by immunohistochemistry for E-cadherin and P-cadherin. CDH1/E-cadherin mutations were determined by next-generation sequencing. The index patient's colectomy showed transmural metastatic ILC harboring a CDH1/E-cadherin p.Q610* mutation. ILC cells displayed different growth patterns in different anatomic layers of the colon wall. In the tunica muscularis propria and the tela submucosa, ILC cells featured noncohesive growth and were E-cadherin-negative and P-cadherin-negative. However, ILC cells invading the mucosa formed cohesive tubular elements in the intercryptal stroma of the lamina propria mucosae. Inter-cryptal ILC cells switched to a P-cadherin-positive phenotype in this microenvironmental niche. In the reference series, colon mucosa infiltration was evident in 13 of 18 patients, one of which showed intercryptal EPS and conversion to cohesive growth as described in the index patient. The large bowel is a common metastatic site in ILC. In endoscopic colon biopsies, the typical noncohesive growth of ILC may be concealed by microenvironment-induced EPS and conversion to cohesive growth.

Novel GATA6-FOXO1 fusions in a subset of epithelioid hemangioma.

The genetic hallmark of epithelioid hemangioma (EH) is the presence of recurrent gene fusions involving FOS and FOSB transcription factors, which occur in one-third of the cases. Certain clinical, pathologic, and genotypic correlations have been described, with FOS-related fusions being more often detected in skeletal and cellular variants of EH, while FOSB gene rearrangements are more commonly associated with atypical histologic features and penile location. These fusions are infrequently detected in the cutaneous or head and neck EH. Overall, two-thirds of EH lack these canonical fusions and remain difficult to classify, especially when associated with atypical features and/or clinical presentations. Triggered by an index case of an intravascular soft tissue EH with a novel GATA6-FOXO1 gene fusion by targeted RNA sequencing (Archer® FusionPlex® Sarcoma Panel), we have investigated 27 additional EH cases negative for FOS and FOSB gene rearrangements for this novel abnormality to determine its recurrent potential, and its association with clinical and pathologic features. Four additional EH cases were found to display GATA6-FOXO1 fusions (18%). There were three females and two males, with a mean age of 32 years old. Three lesions occurred in the head and neck (dura, nasopharyngeal, and cheek), one in the back and one in the leg. Two of these lesions were cutaneous and one was intravascular in the subcutis of the leg. Microscopically, the tumors showed a variegated morphology, with alternating vasoformative and solid components, extravasated red blood cells and mild to moderate cytologic atypia. None showed brisk mitotic activity or necrosis. Tumors were negative for FOS and FOSB by immunohistochemistry. In conclusion, we report a new GATA6-FOXO1 fusion in a subset of EH, with a predilection for skin, and head and neck location. The relationship of this novel molecular subset with the more common FOS/FOSB fusion-positive EH remains to be determined.

Malignant transformation of uterine leiomyoma to myxoid leiomyosarcoma after morcellation associated with ALK rearrangement and loss of 14q.

A 50 year old woman underwent laparoscopic supracervical hysterectomy because of symptomatic fibroids. Histologic examination of samples obtained after morcellation revealed typical uterine leiomyomas in all samples investigated. 28 and 47 months later, respectively, the patient presented with peritoneal spreading of nodules that were surgically removed and histologically classified as leiomyosarcoma. In 3/4 of samples obtained after morcellation copy number/SNP-array hybridization showed complex genomic alterations widely identical to the pattern characterizing the sarcoma. Therefore, we conclude that the leiomyosarcoma had unambiguously developed from one of the leiomyomas as a result of secondary genetic alterations i.e. a rearrangement of ALK and a del(14q). The case is challenging the current risk estimates for spreading of unexpected malignant uterine tumors due to power morcellation and highlights the relevance of certain genetic alterations for rare malignant transformation of uterine benign smooth muscle tumors.

Elevated DMBT1 levels in neonatal gastrointestinal diseases.

Deleted in malignant brain tumor 1 (DMBT1) is involved in innate immunity and epithelial differentiation. Previous studies in adults indicated a strong intestinal expression of DMBT1 and an important role in inflammatory bowel diseases. Here, we analyzed the DMBT1 expression in the fetal gastrointestinal system depending on gestational age and in patients with necrotizing enterocolitis (NEC), volvulus, intestinal perforation (IP), or herniation, representing typical diseases of preterm and term infants. We used immunohistochemistry and RNA in situ hybridization to detect DMBT1 protein and mRNA in fetal tissues, supplemented by postmortem analysis of DMBT1 expression in died newborns and analysis of surgically removed tissues. DMBT1 expression is detectable in the early developmental stages of the gastrointestinal system. In NEC, volvulus, IP, or herniation, characterized by high systemic inflammatory responses, DMBT1 expression is strongly increased. High DMBT1 expression was also found in the bile ducts of older infants with sepsis or cholestasis. The study shows that DMBT1 expression is observed in the developing gastrointestinal system and up-regulated in infants with NEC, volvulus, IP, and herniation. DMBT1 may play a role in epithelial differentiation and local innate immunity during neonatal inflammatory bowel processes.

Uterine fibroids: do we deal with more than one disease?

Uterine fibroids rank among the most frequent symptomatic human tumors at all. Recent data suggest that mutations of the mediator subcomplex 12 gene (MED12) and rearrangements of the gene-encoding high-mobility group protein AT-hook 2 (HMGA2) characterize major genetic subtypes of these tumors, which, for example, differ by their average size. Herein, we have investigated a total of 289 fibroids from 120 patients. Of these fibroids, 256 were fully genetically analyzed. Of the latter group, 20 (7.8%) fibroids had a chromosomal rearrangement of 12q14-15 reflecting a rearranged allele of HMGA2 and 179 (69.9%) fibroids had a mutation of MED12. The remaining tumors had either another genetic abnormality or no detectable abnormality at all. We were able to demonstrate that tumors of both groups also display striking differences of their frequency in individual patients. Whereas 70.0% (14/20) HMGA2-mutated fibroids made their appearance as solitary nodules, 85.5% (153/179) MED12-mutated fibroids occurred as multiple nodules as a rule of independent clonal origin, as reflected by different MED12 mutations. These findings are likely to point to a different pathogenesis of both types of fibroids. In the predominant of these groups so far, an unknown "mutator" may cause independent mutations of MED12, resulting in an independent clonal outgrowth of nodules. Furthermore, the low but existing risk of MED12-mutated fibroids to undergo malignant transformation after a leiomyoma-STUMP (smooth muscle tumors of uncertain malignant potential)-leiomyosarcoma sequence excludes the latter mutation as a suitable stand-alone marker for benign growth.

Cardiac amyloidosis induces up-regulation of Deleted in Malignant Brain Tumors 1 (DMBT1).

BACKGROUND: Amyloidosis is a life-threatening protein misfolding disease and affects cardiac tissue, leading to heart failure, myocardial ischemia and arrhythmia. Amyloid deposits result in oxidative stress, inflammation and apoptosis. The purpose of this study was to examine the role of innate defense components, i.e., Deleted in Malignant Brain Tumors 1 (DMBT1) and the complement system, in different types of cardiac amyloidosis. METHODS: Expression of DMBT1 and of the complement proteins C1q, C3d and C4d in cardiac specimens of patients with different types of amyloidosis were determined by immunohistochemistry and correlated with amyloid deposits stained by Congo red dye. RESULTS: Strong DMBT1 staining adjacent to amyloid deposits was detected in different amyloidosis types, depending on the extent of the deposits. DMBT1 is localized in the endomysium and perimysium, in the endocardium, in the myocytes and in endothelial cells of affected transmural vessels. C1q, C3d and C4d were detected in the amyloid deposits but also in the endomysium and perimysium, in some myocytes, in endothelial cells, in the endocardium, and around the amyloid deposits. CONCLUSIONS: Up-regulated DMBT1 and complement activation in cardiac amyloidosis may be part of the activated pathways induced by protein aggregation and the consecutive inflammatory reaction.

Fibroid explants reveal a higher sensitivity against MDM2-inhibitor nutlin-3 than matching myometrium.

BACKGROUND: Spontaneous cessation of growth is a frequent finding in uterine fibroids. Increasing evidence suggests an important role of cellular senescence in this growth control. Deciphering the underlying mechanisms of growth control that can be expected not only to shed light on the biology of the tumors but also to identify novel therapeutic targets. METHODS: We have analyzed uterine leiomyomas and matching normal tissue for the expression of p14Arf and used explants to see if reducing the MDM2 activity using the small-molecule inhibitor nutlin-3 can induce p53 and activate genes involved in senescence and/or apoptosis. For these studies quantitative real-time RT-PCR, Western blots, and immunohistochemistry were used. Statistical analyses were performed using the student's t test. RESULTS: An in depth analysis of 52 fibroids along with matching myometrium from 31 patients revealed in almost all cases a higher expression of p14Arf in the tumors than in the matching normal tissue. In tissue explants, treatment with the MDM2 inhibitor nutlin-3 induced apoptosis as well as senescence as revealed by a dose-dependent increase of the expression of BAX as well as of p21, respectively. Simultaneously, the expression of the proliferation marker Ki-67 drastically decreased. Western-blot analysis identified an increase of the p53 level as the most likely reason for the increased activity of its downstream markers BAX and p21. Because as a rule fibroids express much higher levels of p14Arf, a major negative regulator of MDM2, than matching myometrium it was then analyzed if fibroids are more sensitive against nutlin-3 treatment than matching myometrium. We were able to show that in most fibroids analyzed a higher sensibility than that of matching myometrium was noted with a corresponding increase of the p53 immunopositivity of the fibroid samples compared to those from myometrium. CONCLUSIONS: The results show that uterine fibroids represent a cell population of advanced cellular age compared to matching myometrium. Moreover, the data point to members of the p53-network as to potential novel therapeutic targets for the treatment of uterine fibroids.

Heparanase expression in head and neck squamous cell carcinomas is associated with reduced proliferation and improved survival.

AIMS: Cellular expression of heparanase, a degrading enzyme of the extracellular matrix, is associated with poorer prognosis in several cancers. The present analysis, has studied the role of heparanase in tumour growth and clinical outcome in patients with head and neck squamous cell carcinoma (HNSCC). METHODS AND RESULTS: We analysed the cellular expression of the active form of heparanase in 71 human HNSCCs, using immunohistochemistry. The results were compared with clinicopathological data and, in 65 cases with immunoreactivity for the proliferation marker, MIB1. Cellular heparanase expression was detected in 41 of 71 (57.74%) cases; in particular, UICC IV-stage tumours showed high heparanase levels. Heparanase was localized mainly in the cytoplasm and, to a lesser extent, at the cell membrane. High levels of heparanase were significantly correlated with an almost four-fold decrease in MIB1 labelling (P = 0.006). Comparison with clinical outcome by multivariate analysis revealed that patients with high-level heparanase expression had prolonged overall survival (P = 0.029). CONCLUSIONS: Although heparanase was mainly found in late-stage HNSCCs, cellular heparanase expression in HNSCCs was associated with prolonged overall survival. We propose that the proliferation-reducing effect of high heparanase levels might outweigh the tumour-promoting effects of heparanase, especially in advanced tumours.

Differentiation therapy exerts antitumor effects on stem-like glioma cells.

PURPOSE: Stem-like tumor cells comprise a highly tumorigenic and therapy-resistant tumor subpopulation, which is believed to substantially influence tumor initiation and therapy resistance in glioma. Currently, therapeutic, drug-induced differentiation is considered as a promising approach to eradicate this tumor-driving cell population; retinoic acid is well known as a potent modulator of differentiation and proliferation in normal stem cells. In glioma, knowledge about the efficacy of retinoic acid-induced differentiation to target the stem-like tumor cell pool could have therapeutic implications. EXPERIMENTAL DESIGN: Stem-like glioma cells (SLGC) were differentiated with all-trans retinoic acid-containing medium to study the effect of differentiation on angiogenesis, invasive growth, as well as radioresistance and chemoresistance of SLGCs. In vivo effects were studied using live microscopy in a cranial window model. RESULTS: Our data suggest that in vitro differentiation of SLGCs induces therapy-sensitizing effects, impairs the secretion of angiogenic cytokines, and disrupts SLGCs motility. Further, ex vivo differentiation reduces tumorigenicity of SLGCs. Finally, we show that all-trans retinoic acid treatment alone can induce antitumor effects in vivo. CONCLUSIONS: Altogether, these results highlight the potential of differentiation treatment to target the stem-like cell population in glioblastoma.

High prevalence of amyloid in 150 surgically removed heart valves--a comparison of histological and clinical data reveals a correlation to atheroinflammatory conditions.

INTRODUCTION: The prevalence, pathophysiology, and clinical indicators of valvular amyloid deposition have not been clarified yet. METHODS: One hundred fifty surgically resected heart valve specimens [67.4+/-1.0 years; aortic stenosis (AS), n=100; aortic regurgitation, n=19; mitral stenosis, n=7; mitral regurgitation, n=24] were qualitatively, semiquantitatively, and immunohistochemically analyzed and correlated with clinical data. RESULTS: Amyloid was found in 83/150 specimens with highest prevalence in AS (74/100), intermediate prevalence in mitral stenosis (2/7) and regurgitation (7/24), and lowest prevalence in aortic regurgitation (2/19). Severe and polymorphic amyloid deposits were almost exclusively found in AS (35/100). Filamentous cloudy amyloid patterns occurred with the same frequency in AS (29/100). A combination of both was found only in AS (n=7/100). By immunohistochemistry, none of the most common amyloid proteins was identified except for a weak staining by the apolipoprotein AI antibody, but more intense adjacent to amyloid deposits. Amyloid correlated with valvular thickening (P<.05), hyperlipidemia (P=.07), coronary artery disease (P=.084), and obesity (P=.082). CONCLUSIONS: Localized valvular amyloid is predominantly found in stenotic aortic valves. It appears to depend on atheroinflammatory conditions and high shear-stress hemodynamics. Further studies are needed to identify the underlying protein.

Staged heart transplantation and chemotherapy as a treatment option in patients with severe cardiac light-chain amyloidosis.

AIMS: The prognosis of advanced cardiac light-chain amyloidosis is poor. Heart transplantation might enable causative therapy and ultimately improve prognosis. METHODS AND RESULTS: Nineteen patients with cardiac amyloidosis but no obvious involvement of other organs were scheduled for heart transplantation. Four to 6 months later, high-dose melphalan chemotherapy and autologous stem cell transplantation (HDM-ASCT) was planned in patients not in complete remission. Seven of nineteen patients died while waiting for heart transplantation. The remaining 12 patients (complete remission, n = 4) underwent surgery. Chemotherapy in patients not in complete remission consisted of HDM-ASCT (n = 5/12; subsequent complete remission, n = 2; partial remission, n = 3) or melphalan-prednisolone (partial remission, n = 1). Two of twelve patients were ineligible for any chemotherapy. Three of twelve patients died [423.5 (105-2131) days] from progressive disease, relapse, or sepsis. The 1- and 3-year survival rates were 83 and 83%, respectively, similar to those of patients undergoing heart transplantation for standard indications. Corresponding survival rates stratified by haematological response were 100 and 100% for complete remission (partial remission, 100 and 100%; progressive disease, 0 and 0%). CONCLUSION: Heart transplantation in advanced cardiac amyloidosis is a promising approach to interrupting the vicious circle of ineligibility for potential curative chemotherapeutic treatment and extremely poor prognosis of cardiac amyloidosis without chemotherapy. Highly urgent heart transplantation combined with subsequent HDM-ASCT appears to offer a successful treatment option to improve the poor outcome of cardiac amyloidosis. However, it should be restricted to highly selected patients in specialized centres.

Deleted in Malignant Brain Tumors 1 is up-regulated in bacterial endocarditis and binds to components of vegetations.

OBJECTIVE: Bacterial endocarditis is a frequent infectious cardiac disease, especially in patients with congenital or acquired heart defects. It is characterized by bacterial colonization of the heart valves and the appearance of vegetations consisting of fibrin, blood cells, and bacteria. The glycoprotein Deleted in Malignant Brain Tumors 1 is a scavenger receptor cysteine-rich protein with functions in innate immunity and epithelial differentiation. Because of the aggregating capacity of Deleted in Malignant Brain Tumors 1, we hypothesized that an up-regulation in bacterial endocarditis may be linked to the development of vegetations. METHODS: Heart tissue of 19 patients with bacterial endocarditis and 10 controls without bacterial endocarditis was analyzed by immunohistochemistry. The effect of human recombinant Deleted in Malignant Brain Tumors 1 on erythrocyte aggregation was measured using an automated red blood cell aggregometer MA1. Binding of human recombinant Deleted in Malignant Brain Tumors 1 to erythrocyte membranes, platelets, fibrin, and fibrinogen was analyzed by Western blotting and enzyme-linked immunosorbent assay. RESULTS: Deleted in Malignant Brain Tumors 1 expression was up-regulated in affected heart valves with bacterial endocarditis and limited to the colonizing bacteria on the heart valves and granulocyte-depleted fibrin/fibrinogen formations, and around localized atheromatosis. Patients with aggressive bacteria showed higher DMBT1 levels than patients with less aggressive bacteria. Human recombinant Deleted in Malignant Brain Tumors 1 aggregates erythrocytes and binds to erythrocyte membranes, platelets, and fibrin/fibrinogen. CONCLUSION: Deleted in Malignant Brain Tumors 1 up-regulation at sites of bacterial endocarditis, its association with platelets and fibrin/fibrinogen, and its ability to aggregate erythrocytes through binding to their membranes indicate a potential role in the development of vegetations and thrombosis.

Angiogenic growth factors in tissue homogenates of HNSCC: expression pattern, prognostic relevance, and interrelationships.

Head and neck squamous cell carcinoma has still a poor prognosis. Since angiogenesis is crucial for tumor growth, a better understanding of the potential clinical relevance as well as the interactions between the numerous proangiogenic growth factors is essential to develop improved therapeutic strategies in these tumors. Expression levels of eight growth factors known to induce angiogenesis (HGF, bFGF, VEGF-A, VEGF-D, PDGF-AB, PDGF-BB, G-CSF, and GM-CSF) were quantitatively measured by ELISA in homogenates of 41 head and neck squamous cell carcinomas. In addition, microvessel density and protein localization of growth factors were assessed by immunohistochemistry. Statistical analysis was performed to assess interrelationships between growth factors analyzed and to correlate protein levels with patient outcome. In 90% of the tissues at least 4/8 growth factors analyzed were detectable. Highest amounts and most frequent expression were found for HGF, bFGF and VEGF-A while PDGF-AB and PDGF-BB were present in two-thirds and G-CSF and GM-CSF in approximately half of the cases. Although there was no significant relation to microvessel density, we identified significant associations for bFGF with HGF and G-CSF as well as of PDGF-AB with those of VEGF-A and PDGF-BB. For the first time we demonstrate that expression levels of HGF as well as that of bFGF and G-CSF in head and neck squamous tumors are negative prognostic factors for patient survival. Our data indicate a network of interrelated and prognostically relevant growth factors in these tumors that have to be taken into consideration when planning an antiangiogenic and antitumor therapy.

Stem cell marker CD133 affects clinical outcome in glioma patients.

PURPOSE: The CD133 antigen has been identified as a putative stem cell marker in normal and malignant brain tissues. In gliomas, it is used to enrich a subpopulation of highly tumorigenic cancer cells. According to the cancer stem cell hypothesis, CD133-positive cells determine long-term tumor growth and, therefore, are suspected to influence clinical outcome. To date, a correlation between CD133 expression in primary tumor tissues and patients' prognosis has not been reported. EXPERIMENTAL DESIGN: To address this question, we analyzed the expression of the CD133 stem cell antigen in a series of 95 gliomas of various grade and histology by immunohistochemistry on cryostat sections. Staining data were correlated with patient outcome. RESULTS: By multivariate survival analysis, we found that both the proportion of CD133-positive cells and their topological organization in clusters were significant (P < 0.001) prognostic factors for adverse progression-free survival and overall survival independent of tumor grade, extent of resection, or patient age. Furthermore, proportion of CD133-positive cells was an independent risk factor for tumor regrowth and time to malignant progression in WHO grade 2 and 3 tumors. CONCLUSIONS: These findings constitute the first conclusive evidence that CD133 stem cell antigen expression correlates with patient survival in gliomas, lending support to the current cancer stem cell hypothesis.

Deleted in Malignant Brain Tumors 1 (DMBT1) is present in hyaline membranes and modulates surface tension of surfactant.

BACKGROUND: Deleted in Malignant Brain Tumors 1 (DMBT1) is a secreted scavenger receptor cysteine-rich protein that binds various bacteria and is thought to participate in innate pulmonary host defense. We hypothesized that pulmonary DMBT1 could contribute to respiratory distress syndrome in neonates by modulating surfactant function. METHODS: DMBT1 expression was studied by immunohistochemistry and mRNA in situ hybridization in post-mortem lungs of preterm and full-term neonates with pulmonary hyaline membranes. The effect of human recombinant DMBT1 on the function of bovine and porcine surfactant was measured by a capillary surfactometer. DMBT1-levels in tracheal aspirates of ventilated preterm and term infants were determined by ELISA. RESULTS: Pulmonary DMBT1 was localized in hyaline membranes during respiratory distress syndrome. In vitro addition of human recombinant DMBT1 to the surfactants increased surface tension in a dose-dependent manner. The DMBT1-mediated effect was reverted by the addition of calcium depending on the surfactant preparation. CONCLUSION: Our data showed pulmonary DMBT1 expression in hyaline membranes during respiratory distress syndrome and demonstrated that DMBT1 increases lung surface tension in vitro. This raises the possibility that DMBT1 could antagonize surfactant supplementation in respiratory distress syndrome and could represent a candidate target molecule for therapeutic intervention in neonatal lung disease.

Combination of thalidomide and cisplatin in an head and neck squamous cell carcinomas model results in an enhanced antiangiogenic activity in vitro and in vivo.

Thalidomide is an immunomodulatory, antiangiogenic drug. Although there is evidence that it might be more effective in combination with chemotherapy the exact mechanism of action is unclear. Therefore, we investigated its effect in combination with metronomically applied cisplatin in a xenotransplant mouse model characteristic for advanced head and neck squamous cell carcinomas, its possible synergistic action in vitro, and which tumor-derived factors might be targeted by thalidomide. Although thalidomide alone was ineffective, a combined treatment with low-dose cisplatin inhibited significant tumor growth, proliferation and angiogenesis in vivo as well as migration and tube formation of endothelial cells in vitro. Noteworthy, the latter effect was enhanced after coapplication of cisplatin in nontoxic doses. An inhibitory effect on tumor cell migration was also observed suggesting a direct antitumor effect. Although thalidomide alone did not influence cell proliferation, it augmented antiproliferative response after cisplatin application emphasizing the idea of a potentiated effect when both drugs are combined. Furthermore, we could show that antiangiogenic effects of thalidomide are related to tumor-cell derived factors including vascular endothelial growth factor, basic fibroblast growth factor, hepatocyte growth factor and Il-8 some known and with, granulocyte colony stimulating growth factor and granulocyte macrophage colony stimulating growth factor, some new target molecules of thalidomide. Altogether, our findings reveal new insights into thalidomide-mediated antitumor and antiangiogenic effects and its interaction with cytostatic drugs.

Antiglioma activity of 2,2':6',2"-terpyridineplatinum(II) complexes in a rat model--effects on cellular redox metabolism.

The mammalian thioredoxin system, comprising the selenoenzyme thioredoxin reductase (TrxR) and the 12-kDa protein thioredoxin (Trx), is implicated in thiol-mediated antioxidant defense and redox regulatory processes including transcriptional control, DNA synthesis, and apoptosis. Cell proliferation supported by the thioredoxin system can be suppressed by TrxR inhibition. In this study, we assessed the effects of the potent hTrxR inhibitors 4-mercaptopyridine (4'-chloro-2,2':6',2"-terpyridine)platinum nitrate (I(23)2N) and 2-mercaptopyridine (4'-chloro-2,2':6',2"-terpyridine)platinum nitrate (I(25)2N) on glioblastoma in a rat model. These compounds show no or little cross-resistance with cisplatin and are thus of great clinical interest. Triple intravenous application of 25-35 mg/kg of the compounds led to a significant decrease of tumor growth as determined by magnetic resonance imaging. Metabolic as well as redox parameters in the blood of the animals were not altered. However, TrxR activity was significantly decreased in the tumor tissue, and redox parameters-including glutathione concentrations, total antioxidant status, and the activities of different antioxidant enzymes-showed tissue-specific variations. As indicated by different apoptotic markers, the antitumor activity of I(23)2N is not mediated by the induction of programmed cell death but rather by hTrxR inhibition and DNA intercalation leading to cell cycle arrest.

Heparanase expression at the invasion front of human head and neck cancers and correlation with poor prognosis.

PURPOSE: Head and neck squamous cell carcinomas (HNSCC) are characterized by a poor prognosis due to aggressive, recurrent tumor growth. Expression of the extracellular matrix-degrading enzyme heparanase was associated with poorer prognosis in several cancers. We analyzed the presence of heparanase in HNSCC tissues and tumor cells and its potential prognostic significance. EXPERIMENTAL DESIGN: We analyzed the expression of the active form of heparanase in HNSCC tissues in corresponding tumor cell cultures and after xenotransplantation of tumor cell cultures into NOD/Scid mice by immunohistochemistry, Western blot analysis, and reverse transcription-PCR in altogether 25 patients and did a comparison with clinicopathologic data of the patients. RESULTS: Heparanase expression in situ was detected in all tumor biopsies in the tumor stroma and in tumor cells from 13 of 19 primary tumors and 9 of 12 lymph node metastases. Heparanase was localized in disseminated tumor cells, in tumor cell clusters invading adjacent stromal tissues, and in tumor cells at the tumor invasion front. Lymph node metastases expressed higher levels of heparanase compared with corresponding primary tumors. In contrast to a heterogeneous expression pattern in tumor tissues, all corresponding HNSCC tumor cell cultures showed a rather homogeneous heparanase expression on the mRNA and protein levels. Comparison of heparanase expression in situ and in corresponding tumor cell cultures in vitro or after xenotransplantation into NOD/Scid mice revealed that heparanase expression was regulated in vivo. Lack of heparanase in tumor cells from primary tumors or lymph node metastases was correlated with prolonged disease-free survival and overall survival. CONCLUSION: Heparanase expression seems to be involved in the invasiveness and aggressiveness of HNSCC.