L1CAM in human cancer.

L1 cell adhesion molecule (L1CAM) is one of the first neural adhesion molecules described with important functions in the development of the nervous system. Subsequent work discovered that L1CAM is expressed in many human cancers and is often associated with bad prognosis. This is most likely due to the motility and invasion promoting function of L1CAM. Here, we describe the path L1CAM has taken from a neural adhesion molecule to a recognized tumor antigen. We summarize the literature on L1CAM expression in cancers and pre-cancerous lesions. We focus on the genetic elements required for its re-expression and highlight preclinical studies for targeted therapy. The data suggest that L1CAM is a valuable diagnostic/prognostic marker and an attractive target for the therapy of several human cancers.

L1CAM is expressed in triple-negative breast cancers and is inversely correlated with androgen receptor.

BACKGROUND: Breast cancer is a heterogeneous disease displaying distinct molecular features and clinical outcome. The molecular profile of triple-negative breast cancers (TNBCs) overlaps with that of basal-like breast cancers that in turn show similarities with high-grade serous ovarian and endometrial carcinoma. L1CAM is an established biomarker for the latter cancers and we showed before that approximately 18% of primary breast cancers are positive for L1CAM and have a bad prognosis. Here we analysed the expression of L1CAM breast cancer subtypes. METHODS: We analyzed mRNA and protein expression data from different breast cancer cohorts for L1CAM, estrogen receptor, progesterone receptor, Her-2 and Androgen receptor (AR) and correlated the data. We performed Western blot analysis on tumor cell lysates and carried out chromatin-immuno-precipitation (CHIP) after AR overexpression. RESULTS: We find that L1CAM is expressed preferentially though not exclusively in TNBCs. Using the human cancer genome atlas database and two independent breast cancer cohorts we find that L1CAM is inversely correlated with androgen receptor (AR) expression. We found that L1CAM(high)AR(low) primary breast tumors have the worst clinical outcome. Overexpression of AR in MDA-MB436 breast cancer cells decreased L1CAM expression at the protein and mRNA level and CHIP-analysis revealed binding of AR to the L1CAM promoter region. CONCLUSIONS: These results suggest that L1CAM in breast cancer is under AR control. The data also strongly advocate the use of L1CAM assessment in breast cancer diagnosis. We suggest that L1CAM expression could be causally related to the bad prognosis of TNBCs.

Determination of tumor-infiltrating CD8+ lymphocytes in human ovarian cancer.

Tumor-infiltrating immune cells and their prognostic value have been analyzed in various malignancies. Although tissue microarray (TMA) has been used in some of these studies, it is still questionable whether this technique can represent the results of infiltrating CD8+ cells obtained from whole-tissue sections (WTS). The aim of this study was to assess and compare the density of tumor-infiltrating CD8+ cells in ovarian cancer using TMA and WTS. CD8+ lymphocytes were immunohistochemically stained on WTS and TMA cores from 37 ovarian cancer patients and quantified using the image analysis software HistoQuest. Four different areas were selected on the WTS, namely (i) tumor; (ii) stroma; (iii) mixed; and (iv) dense, whereby dense represented areas of most abundant CD8+ cells. On the TMA, (i) the whole TMA cores and (ii) areas containing only epithelial tumor tissue were analyzed. The Pearson correlation and principal component analysis was used to estimate the correlation of results from different techniques. CD8+ lymphocytes showed highly correlated measurements between tumor, mixed, and dense areas. Moderate correlations were found between each of these 3 measurements and stroma. CD8+ cell counts from WTS showed moderate correlation with TMA cell counts. Consistently, principal component analysis showed 3 clusters (i) tumor, dense, mixed; (ii) stroma; and (iii) TMA areas. Taken together, when the prognostic impact of tumor-infiltrating CD8+ cells in ovarian cancer is investigated with TMA technique, a moderate correlation with WTS results has to be considered.

CD24 controls Src/STAT3 activity in human tumors.

CD24 is a glycosyl-phosphatidylinositol-anchored membrane protein that is frequently over-expressed in a variety of human carcinomas and is correlated with poor prognosis. In cancer cell lines, changes of CD24 expression can alter several cellular properties in vitro and tumor growth in vivo. However, little is known about how CD24 mediates these effects. Here we have analyzed the functional consequences of CD24 knock-down or over-expression in human cancer cell lines. Depletion of CD24 reduced cell proliferation and adhesion, enhanced apoptosis, and regulated the expression of various genes some of which were identified as STAT3 target genes. Loss of CD24 reduced STAT3 and FAK phosphorylation. Diminished STAT3 activity was confirmed by specific reporter assays. We found that reduced STAT3 activity after CD24 knock-down was accompanied by altered Src phosphorylation. Silencing of Src, similar to CD24, targeted the expression of prototype STAT3-regulated genes. Likewise, the over-expression of CD24 augmented Src-Y416 phosphorylation, the recruitment of Src into lipid rafts and the expression of STAT3-dependent target genes. An antibody to CD24 was effective in reducing tumor growth of A549 lung cancer and BxPC3 pancreatic cancer xenografts in mice. Antibody treatment affected the level of Src-phosphorylation in the tumor and altered the expression of STAT3 target genes. Our results provide evidence that CD24 regulates STAT3 and FAK activity and suggest an important role of Src in this process. Finally, the targeting of CD24 by antibodies could represent a novel route for tumor therapy.

L1CAM is required for early dissemination of fallopian tube carcinoma precursors to the ovary.

Most ovarian high-grade serous carcinomas (HGSC) arise from Serous Tubal Intraepithelial Carcinoma (STIC) lesions in the distal end of the fallopian tube (FT). Formation of STIC lesions from FT secretory cells leads to seeding of the ovarian surface, with rapid tumor dissemination to other abdominal structures thereafter. It remains unclear how nascent malignant cells leave the FT to colonize the ovary. This report provides evidence that the L1 cell adhesion molecule (L1CAM) contributes to the ability of transformed FT secretory cells (FTSEC) to detach from the tube, survive under anchorage-independent conditions, and seed the ovarian surface. L1CAM was highly expressed on the apical cells of STIC lesions and contributed to ovarian colonization by upregulating integrins and fibronectin in malignant cells and activating the AKT and ERK pathways. These changes increased cell survival under ultra-low attachment conditions that mimic transit from the FT to the ovary. To study dissemination to the ovary, we developed a tumor-ovary co-culture model. We showed that L1CAM expression was important for FT cells to invade the ovary as a cohesive group. Our results indicate that in the early stages of HGSC development, transformed FTSECs disseminate from the FT to the ovary in a L1CAM-dependent manner.

Loss of EpCAM expression in breast cancer derived serum exosomes: role of proteolytic cleavage.

OBJECTIVE: Cancer cells in the body release soluble and membranous factors that manipulate the tumor environment to facilitate growth and survival. Recent years have provided evidence that small microvesicles that are termed exosomes may play a pivotal role in this process. Exosomes are membrane vesicles with a size of 40-100 nm that are released by both tumor and normal cells and can be found in various body fluids. Tumor-derived exosomes carry functional proteins, mRNAs, and miRNAs and could serve as novel platform for tumor diagnosis and prognosis. However, marker proteins that allow enrichment of tumor-derived exosomes over normal exosomes are less well defined. METHODS: We used Western blot analysis and antibody coupled magnetic beads to characterize CD24 and EpCAM as markers for exosomes. We investigated ovarian carcinoma ascites, pleural effusions and serum of breast carcinoma patients. As non-tumor derived control we used exosomes from ascites of liver cirrhosis patients. RESULTS: Exosomes could be isolated from all body fluids and contained marker proteins as well as miRNAs. We observed that CD24 and EpCAM were selectively present on ascites exosomes of tumor patients and copurified together on anti-EpCAM or anti-CD24 magnetic beads. In breast cancer patients CD24 was present but EpCAM was absent from serum exosomes. Instead, the intact EpCAM ectodomain was recovered in a soluble form. We provide evidence that EpCAM can be cleaved from exosomes via serum metalloproteinase(s). CONCLUSION: Loss of EpCAM on serum exosomes may hamper enrichment by immune-affinity isolation. We suggest that CD24 could be an additional marker for the enrichment of tumor-derived exosomes from blood.

Up-regulation of L1CAM is linked to loss of hormone receptors and E-cadherin in aggressive subtypes of endometrial carcinomas.

Endometrial carcinomas (ECs) are classified into type 1 (less aggressive) and type 2 (aggressive) tumours that differ in genetic alterations. So far, reliable immunohistochemical markers that can identify patients with high risk for recurrence are rare. We have defined the expression of L1 cell adhesion molecule (L1CAM), a biomarker previously identified for EC, and compared its expression to oestrogen receptor (ER)/progesterone receptor (PR) and E-cadherin. We found that L1CAM was absent in normal endometrium and the vast majority of endometrioid ECs (type 1) but was strongly expressed in serous and clear-cell ECs, considered as type 2. 78/272 cases were identified as L1CAM-positive endometrioid ECs that were correlated with a poor prognosis. Strikingly, we observed an inverse relationship between L1CAM and ER/PR/E-cadherin expression in all ECs. In mixed ECs, composed of endometrioid (L1CAM(-) ER/PR(+) E-cadherin(+)) and clear-cell/serous (L1CAM(+) ER/PR(-) E-cadherin(-)), both phenotypes were co-expressed. In some of these cases L1CAM was up-regulated at the leading edge of the tumour, where ER/PR and E-cadherin expression were selectively lost. In EC cell lines treated with the epithelial-mesenchymal transition (EMT) inducer TGFbeta1, L1CAM and vimentin were strongly up-regulated, while E-cadherin expression was reduced. The treatment also resulted in an increased expression of the EMT transcription factor Slug and an enhanced cell invasion. Depletion of Slug by siRNA knockdown prevented both L1CAM up-regulation and enhanced cell invasion. According to our analysis, we suggest that L1CAM is a novel marker for EMT in ECs and that L1CAM-typing could identify endometrioid ECs that have type 2-like features and are at high risk for recurrence.

The role of macrophage-derived IL-1 in induction and maintenance of angiogenesis.

Inflammation and angiogenesis are pivotal processes in the progression of many diseases, including malignancies. A hypoxic microenvironment often results in a milieu of proinflammatory and proangiogenic cytokines produced by infiltrating cells. We assessed the role of macrophage-derived hypoxia-associated cytokines in promoting inflammation and angiogenesis. Supernatants of macrophages, stimulated under hypoxia with or without an inflammatory stimulus (LPS), promoted angiogenesis when incorporated into Matrigel plugs. However, neutralization of IL-1 in the supernatants, particularly IL-1beta, completely abrogated cell infiltration and angiogenesis in Matrigel plugs and reduced vascular endothelial growth factor (VEGF) levels by 85%. Similarly, supernatants from macrophages of IL-1beta knockout mice did not induce inflammatory or angiogenic responses. The importance of IL-1 signaling in the host was demonstrated by the dramatic reduction of inflammatory and angiogenic responses in Matrigel plugs that contained macrophage supernatants from control mice which had been implanted in IL-1 receptor type I knockout mice. Myeloid cells infiltrating into Matrigel plugs were of bone marrow origin and represented the major source of IL-1 and other cytokines/chemokines in the plugs. Cells of endothelial lineage were the main source of VEGF and were recruited mainly from neighboring tissues, rather than from the bone marrow. Using the aortic ring sprouting assay, it was shown that in this experimental system, IL-1 does not directly activate endothelial cell migration, proliferation and organization into blood vessel-like structures, but rather activates infiltrating cells to produce endothelial cell activating factors, such as VEGF. Thus, targeting IL-1beta has the potential to inhibit angiogenesis in pathological situations and may be of considerable clinical value.

Expression and prognostic value of L1-CAM in breast cancer.

The L1 adhesion molecule (L1-CAM) is associated with impaired prognosis in many carcinomas. However, limited information about its expression in breast cancer tissue is available. Therefore, we carried out an analysis on L1 expression in primary breast cancers using a combination of Western blot, DNA-microarray analysis and immunohistochemistry. We observed L1 protein and mRNA overexpression in 14-15% of the carcinomas and this was confirmed by immunohistochemical staining. High L1 expression was associated with nodal involvement, high grading, human epidermal growth receptor 2 (Her-2), plasminogen activator inhibitor 1 (PAI-1) and vascular endothelial growth factor (VEGF) expression and a negative estrogen receptor (ER) status, but not with neuroendocrine markers. Moreover, patients with tumors showing high L1-CAM expression had a shorter disease-free and overall survival. Given the emerging functional role of L1 in promoting tumor cell migration, invasion, tumor growth and metastasis, our results suggest that L1 may have this function in breast cancer as well.

Interleukin-1beta-driven inflammation promotes the development and invasiveness of chemical carcinogen-induced tumors.

The role of microenvironment interleukin 1 (IL-1) on 3-methylcholanthrene (3-MCA)-induced carcinogenesis was assessed in IL-1-deficient mice, i.e., IL-1beta(-/-), IL-1alpha(-/-), IL-1alpha/beta(-/-) (double knockout), and mice deficient in the naturally occurring inhibitor of IL-1, the IL-1 receptor antagonist (IL-1Ra). Tumors developed in all wild-type (WT) mice, whereas in IL-1beta-deficient mice, tumors developed slower and only in some of the mice. In IL-1Ra-deficient mice, tumor development was the most rapid. Tumor incidence was similar in WT and IL-1alpha-deficient mice. Histologic analyses revealed fibrotic structures forming a capsule surrounding droplets of the carcinogen in olive oil, resembling foreign body-like granulomas, which appeared 10 days after injection of 3-MCA and persisted until the development of local tumors. A sparse leukocyte infiltrate was found at the site of carcinogen injection in IL-1beta-deficient mice, whereas in IL-1Ra-deficient mice, a dense neutrophilic infiltrate was observed. Treatment of IL-1Ra-deficient mice with recombinant IL-1Ra but not with an inhibitor of tumor necrosis factor abrogated the early leukocytic infiltrate. The late leukocyte infiltrate (day 70), which was dominated by macrophages, was also apparent in WT and IL-1alpha-deficient mice, but was nearly absent in IL-1beta-deficient mice. Fibrosarcoma cell lines, established from 3-MCA-induced tumors from IL-1Ra-deficient mice, were more aggressive and metastatic than lines from WT mice; cell lines from IL-1-deficient mice were the least invasive. These observations show the crucial role of microenvironment-derived IL-1beta, rather than IL-1alpha, in chemical carcinogenesis and in determining the invasive potential of malignant cells.

Copper-67 radioimmunotherapy and growth inhibition by anti-L1-cell adhesion molecule monoclonal antibodies in a therapy model of ovarian cancer metastasis.

PURPOSE: We examined the tumor-targeting and therapeutic effects of (67)Cu-labeled single amino acid mutant forms of anti-L1 monoclonal antibody chCE7 in nude mice with orthotopically implanted SKOV3ip human ovarian carcinoma cells. EXPERIMENTAL DESIGN: For radioimmunotherapy, chCE7 antibodies with a mutation of histidine 310 to alanine (chCE7H310A) and a mutation of asparagine 297 to glutamine (chCE7agl) were generated to achieve more rapid blood clearance. Biodistributions of (67)Cu-4-(1,4,8,11-tetraazacyclotetradec-1-yl)-methyl benzoic acid tetrachloride (CPTA)-labeled mutant antibodies were measured in nude mice bearing SKOV3ip human ovarian cancer metastases. The effects of single i.v. injections of (67)Cu-chCE7agl alone on tumor reduction and survival were investigated. In addition, a combination of low-dose (67)Cu-radioimmunotherapy with unlabeled anti-L1 antibody L1-11A on survival was investigated. RESULTS: (67)Cu-CPTA-chCE7agl showed high (up to 49% ID/g) and persistent (up to 168 h) uptake in SKOV3ip metastases, with low levels in normal tissues. (67)Cu-CPTA-chCE7H310A revealed a shorter half-life in the blood and a lower tumor uptake and retention. A single low dose of 4 MBq of (67)Cu-chCE7agl reduced tumor growth but did not prolong survival significantly, whereas a single 10.5 MBq dose of (67)Cu-chCE7agl reduced tumor growth and prolonged survival significantly. The combination of unlabeled monoclonal antibody L1-11A with a subtherapeutic dose of (67)Cu-radioimmunotherapy also prolonged survival significantly. CONCLUSION: The results show improved pharmacokinetics and biodistributions as well as the therapeutic effect of the (67)Cu-labeled single amino acid mutant chCE7agl. Therapeutic data indicate, for the first time, the feasibility of combining anti-L1-directed growth inhibition and (67)Cu-radioimmunotherapy, thereby increasing the efficiency of antibody treatment of metastatic ovarian carcinoma.

Expression of p53 in the evolution of squamous cell carcinoma: correlation with the histology of the lesion.

BACKGROUND: The evolution of squamous cell carcinoma (SCC) on sun-exposed areas is a multistep process triggered by ultraviolet radiation (UVR), in which precursor lesions exist. However, the exact classification of the various lesions in this process, mainly solar keratosis (SK), is still disputed, and its pathogenesis requires further clarification. OBJECTIVE: To further elucidate the evolution of SCC on sun-damaged skin by correlating the levels of p53 protein expression, a parameter that reflects UVR damage to cells, and the morphology of the lesions that develop on sun-exposed areas. METHODS: Biopsy specimens from normal skin (n = 4), normal skin with various degrees of solar elastosis (SE) (n = 16), various degrees of SK (n = 17) and SCCs from sun-exposed (n = 12) and sun-protected (n = 7) areas were stained with anti-p53 antibodies. A semiquantitative evaluation of the degree of staining was performed and correlated with the histological features. RESULTS: Nuclear staining in keratinocytes was observed already in normal skin with mild SE and was increased gradually to its highest level of expression in advanced SK. It was also expressed in SCCs, but to a lesser degree. Statistical analysis revealed association between the morphology of the lesion and the level of p53 expression (P < .01); it also showed that in general the level of p53 is correlated with the histology of the lesion (P < .001). Furthermore, with regard to p53 expression, two groups of lesions exist: one showing a low level of expression of p53 that includes normal skin, skin with various degrees of SE and SCC from sun-protected areas, and a second group showing a high level of expression that includes SK and SCC occurring on sun-damaged skin. LIMITATION: This is an immunohistochemical study of relatively few cases and in which the antibody detects all types of p53 protein. CONCLUSIONS: This study furnishes further evidence that the development of SCC on sun-damaged skin is a gradual process not only morphologically but also on the molecular level. The process starts already in normal-appearing epidermis with SE. In that respect, SK should be regarded as a part of the continuum in the development of SCC, analogous to the situation in other epithelia. The molecular events involved in the development of SCC on sun-exposed areas may be different from those involving the development of SCC on sun-protected areas.

Expression profile analysis in multiple human tumors identifies L1 (CD171) as a molecular marker for differential diagnosis and targeted therapy.

L1 cell adhesion molecule (CD171) represents a strongly unfavorable prognostic biomarker for ovarian and endometrial carcinomas. Here we carried out an immunohistochemical survey of L1 expression in normal adults and in a broad range of benign and malignant tumors using monoclonal antibody L1-11A and the novel monoclonal antibody L1-14.10. In normal tissues, L1 was expressed in the collecting tubules of adult tissues and pediatric kidney and in peripheral nerve bundles. In tumors of the female genital tract, L1 was detected in adenocarcinomas of the cervix and fallopian tubes, in addition to ovarian and endometrial carcinomas. Nongynecological tumors expressing L1 comprised malignant melanoma, colon adenocarcinoma positive to chromogranin, clear-cell adenocarcinoma of the urinary bladder, pheochromocytoma, small cell lung carcinoma, and tumors of the nervous system. L1 was absent in breast carcinoma, gastrointestinal tract carcinomas, gastrointestinal carcinoids, renal clear-cell carcinomas, prostate adenocarcinomas, and mesotheliomas. Surprisingly, L1 expression in established breast and renal carcinoma cell lines was not a predictor for its presence in these human tumors in vivo. Our results suggest that L1 expression in tumors is not ubiquitous but restricted to certain subtypes and may be a helpful molecular marker for differential diagnosis and target for antibody-based therapy.

L1CAM Expression is Related to Non-Endometrioid Histology, and Prognostic for Poor Outcome in Endometrioid Endometrial Carcinoma.

The majority of endometrial carcinomas are classified as Type I endometrioid endometrial carcinomas (EECs) and have a good prognosis. Type II non-endometrioid endometrial carcinomas (NEECs) have a significant worse outcome. Yet, 20 % of the EECs are associated with an unexplained poor outcome. The aim of this study was to determine if L1CAM expression, a recently reported biomarker for aggressive tumor behavior in endometrial carcinoma, was associated with clinicopathological features of EECs. A total of 103 patients diagnosed as EEC at the Radboud University Medical Centre, based on the pathology report were selected. L1CAM status of these tumors was determined, and histologic slides were reviewed by two expert pathologists. L1CAM-positivity was observed in 17 % (18/103). Review of the diagnostic slides revealed that 11 out of these 18 L1CAM-positive tumors (61 %) contained a serous- or mixed carcinoma component that was not initially mentioned in the pathology report. L1CAM-expression was associated with advanced age, poor tumor grade, and lymphovascular space invasion. A worse five year progression free survival rate was observed for patients with L1CAM-positive tumors (55.6 % for the L1CAM-positive group, compared to 83.3 % for the L1CAM-negative group P = 0.01). L1CAM expression carries prognostic value for histologically classified EEC and supports the identification of tumors with a NEEC component.

L1 expression as a predictor of progression and survival in patients with uterine and ovarian carcinomas.

BACKGROUND: Ovarian and uterine carcinomas are the most common cause of cancer-related deaths in gynecological malignant diseases. We aimed to assess whether the L1 adhesion molecule, an important mediator for cell migration for neural and tumour cells, is expressed in these carcinomas. METHODS: We investigated L1 expression by immunohistochemistry, RT-PCR, and Western blot analysis of tumour samples. Soluble L1 in the serum was detected by ELISA and immunoprecipitation. FINDINGS: We detected the L1 adhesion molecule in ovarian and uterine tumours in a stage-dependent manner. In a retrospective study L1 was found in 46 of 58 ovarian carcinomas and 20 of 72 uterine adenocarcinomas. L1 expression was an excellent predictor of poor outlook (p<0.00001). Patients with L1 positive uterine tumours were at high risk for progression even in the endometrioid-type tumours, which usually have a favourable prognosis. In uterine tumours, expression of L1 in curettage samples enabled us to identify aggressive tumours before the operation. Soluble L1 was specifically detected in serum samples from patients with ovarian and uterine tumours. ADAM10, which was implicated in previous studies as L1 sheddase, was expressed in tumours in which soluble L1 was present in the serum. INTERPRETATION: L1 is overexpressed in ovarian and uterine carcinomas and is associated with short survival. L1 can serve as a new marker for prediction of clinical outcome and could be helpful to identify patients with uterine tumours who are at high risk for recurrent disease. L1 expression and cleavage could promote dissemination of tumours by facilitating cell migration.

ADAM10-mediated cleavage of L1 adhesion molecule at the cell surface and in released membrane vesicles.

Cells can release membrane components in a soluble form and as membrane vesicles. L1, an important molecule for cell migration of neural and tumor cells, is released by membrane-proximal cleavage, and soluble L1 promotes cell migration. Release of L1 is enhanced by shedding inducers such as phorbol ester and pervanadate, but it is also enhanced by depletion of cellular cholesterol with methyl-beta-cyclodextrin (MCD). How such different compounds can induce shedding is presently unknown. We show here that ADAM10 is involved in L1 cleavage, which occurs at the cell surface and in the Golgi apparatus. MCD and pervanadate treatment induced the release of microvesicles containing full-length L1 and the active form of ADAM10. L1 cleavage occurred in isolated vesicles. L1-containing microvesicles could trigger haptotactic cell migration. Only the neural L1 form carrying the RSLE signal for clathrin-dependent endocytosis was recruited and cleaved in vesicles. Phorbol ester treatment activated L1 cleavage predominantly at the cell surface. Our results provide evidence for two pathways of L1 cleavage, based on ADAM10 localization, that can be activated differentially: 1) direct cleavage at the cell surface, and 2) release and cleavage in secretory vesicles most likely derived from the Golgi apparatus. The findings establish a novel role for ADAM10 as a vesicle-based protease.

L1 adhesion molecule (CD 171) in development and progression of human malignant melanoma.

The L1 adhesion molecule (CD171) plays an important role in axon guidance and cell migration in the nervous system. In the human, L1 is expressed on tumors derived from neurocrest and on certain carcinomas. We have analyzed immunohistochemically L1 expression on paraffin embedded specimens of acquired melanocytic nevi, primary cutaneous melanomas, and cutaneous and lymph node metastases of malignant melanomas. We found an increase in L1 immunoreactivity in malignant melanomas and metastases of malignant melanomas as compared to acquired melanocytic nevi that was statistically significant (P<0.05). Additionally, a correlation of L1 immunoreactivity with histological data of prognostic value such as Clark level and the expression of alphav-integrins was found. We detected soluble L1 in the conditioned medium of cultivated melanoma cells but only in 1/40 serum samples from a panel of melanoma patients representing various stages of disease. Our findings suggest that the presence of L1 might contribute to tumor progression by promoting cell adhesion and migration.

L1 (CD171) as a novel biomarker for ovarian and endometrial carcinomas.

The L1 molecule has emerged as a promising new biomarker for the diagnosis and prognosis of human ovarian and endometrial tumors. It was initially described as an adhesion molecule for neural cells but its function on tumor cells is less well known. In this article, the role of L1 in promoting tumor cell adhesion and migration is discussed. The question of how L1 determination in tumor tissue samples, serum and ascites could potentially improve the diagnosis and monitoring of gynecologic tumor patients is also addressed. The presence of L1 in tissue and serum was found to be associated with recurrent disease and short survival, independently of the tumor's histological type. This provides an alternative classification of gynecologic tumors according to their aggressiveness rather than their histology. L1 expression was correlated with disease progression even in patients with Stage I endometrioid-type endometrial tumors, identifying them as high-risk patients on preoperative curettage specimens. Monitoring of soluble L1 during the follow-up period was found to signal disease progression and recurrence before clinical symptoms occur. L1-based diagnosis and prognosis has the potential to contribute to an improved disease management and could represent the basic rationale for novel tailored therapy.

Aspirin decreases vascular endothelial growth factor release during myocardial ischemia.

BACKGROUND: Vascular Endothelial Growth Factor (VEGF) is an important angiogenesis factor involved in pathophysiology of cardiovascular diseases. Controlling this factor's level in the serum might have significant prognostic outcomes. METHODS: Twenty-four patients undergoing coronary artery bypass grafting were prospectively categorized into two groups according to aspirin administration before surgery. Vascular Endothelial Growth Factor levels were compared and correlated and adjusted with platelets count between two groups in the serum, before and after the surgery. Serum creatine kinase (CK) levels were determined before and after the operation in parallel to other clinical data. RESULTS: Vascular Endothelial Growth Factor levels were significantly lower in patients of the aspirin group compared to those of the non-aspirin group; 94+/-61 vs. 241+/-118 pg/ml, p=0.0003, respectively, this-despite an absence of difference in the platelet count between the groups. These titers decreased postoperatively in both groups, 94+/-61 to 10+/-9 pg/ml, p=0.001 in aspirin group and from 241+/-118 to 84+/-54 pg/ml, p=0.001 in control group. Serum creatine kinase levels were higher in the non-aspirin group, 214+/-83 u/l compared to 70+/-32 u/l in the aspirin group. Creatine kinase levels increased significantly postoperatively in both groups; however, the aspirin group had a significantly lower creatine kinase levels compared to non-aspirin group, 107+/-51 vs. 401+/-127 u/l, respectively, p=<0.0001. A significant correlation was seen between VEGF levels and platelets count in both groups, r=0.5. CONCLUSIONS: Aspirin treated patients have lower Vascular Endothelial Growth Factor titer levels in the perioperative course. This difference between the aspirin and the non-aspirin group is not accounted for by the platelets count.

A standardized staining protocol for L1CAM on formalin-fixed, paraffin-embedded tissues using automated platforms.

The L1 cell adhesion molecule (L1CAM) is overexpressed in many human cancers and can serve as a biomarker for prognosis in most of these cancers (including type I endometrial carcinomas). Here we provide an optimized immunohistochemical staining procedure for a widely used automated platform (VENTANA™), which has recourse to commercially available primary antibody and detection reagents. In parallel, we optimized the staining on a semi-automated BioGenix (i6000) immunostainer. These protocols yield good stainings and should represent the basis for a reliable and standardized immunohistochemical detection of L1CAM in a variety of malignancies in different laboratories.