LIF Drives Neural Remodeling in Pancreatic Cancer and Offers a New Candidate Biomarker.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by extensive stroma and pathogenic modifications to the peripheral nervous system that elevate metastatic capacity. In this study, we show that the IL6-related stem cell-promoting factor LIF supports PDAC-associated neural remodeling (PANR). LIF was overexpressed in tumor tissue compared with healthy pancreas, but its receptors LIFR and gp130 were expressed only in intratumoral nerves. Cancer cells and stromal cells in PDAC tissues both expressed LIF, but only stromal cells could secrete it. Biological investigations showed that LIF promoted the differentiation of glial nerve sheath Schwann cells and induced their migration by activating JAK/STAT3/AKT signaling. LIF also induced neuronal plasticity in dorsal root ganglia neurons by increasing the number of neurites and the soma area. Notably, injection of LIF-blocking antibody into PDAC-bearing mice reduced intratumoral nerve density, supporting a critical role for LIF function in PANR. In serum from human PDAC patients and mouse models of PDAC, we found that LIF titers positively correlated with intratumoral nerve density. Taken together, our findings suggest LIF as a candidate serum biomarker and diagnostic tool and a possible therapeutic target for limiting the impact of PANR in PDAC pathophysiology and metastatic progression.Significance: This study suggests a target to limit neural remodeling in pancreatic cancer, which contributes to poorer quality of life and heightened metastatic progression in patients. Cancer Res; 78(4); 909-21. ©2017 AACR.

Collagen-derived proline promotes pancreatic ductal adenocarcinoma cell survival under nutrient limited conditions.

Tissue architecture contributes to pancreatic ductal adenocarcinoma (PDAC) phenotypes. Cancer cells within PDAC form gland-like structures embedded in a collagen-rich meshwork where nutrients and oxygen are scarce. Altered metabolism is needed for tumour cells to survive in this environment, but the metabolic modifications that allow PDAC cells to endure these conditions are incompletely understood. Here we demonstrate that collagen serves as a proline reservoir for PDAC cells to use as a nutrient source when other fuels are limited. We show PDAC cells are able to take up collagen fragments, which can promote PDAC cell survival under nutrient limited conditions, and that collagen-derived proline contributes to PDAC cell metabolism. Finally, we show that proline oxidase (PRODH1) is required for PDAC cell proliferation in vitro and in vivo. Collectively, our results indicate that PDAC extracellular matrix represents a nutrient reservoir for tumour cells highlighting the metabolic flexibility of this cancer.

Cancer-associated fibroblast-derived annexin A6+ extracellular vesicles support pancreatic cancer aggressiveness.

The intratumoral microenvironment, or stroma, is of major importance in the pathobiology of pancreatic ductal adenocarcinoma (PDA), and specific conditions in the stroma may promote increased cancer aggressiveness. We hypothesized that this heterogeneous and evolving compartment drastically influences tumor cell abilities, which in turn influences PDA aggressiveness through crosstalk that is mediated by extracellular vesicles (EVs). Here, we have analyzed the PDA proteomic stromal signature and identified a contribution of the annexin A6/LDL receptor-related protein 1/thrombospondin 1 (ANXA6/LRP1/TSP1) complex in tumor cell crosstalk. Formation of the ANXA6/LRP1/TSP1 complex was restricted to cancer-associated fibroblasts (CAFs) and required physiopathologic culture conditions that improved tumor cell survival and migration. Increased PDA aggressiveness was dependent on tumor cell-mediated uptake of CAF-derived ANXA6+ EVs carrying the ANXA6/LRP1/TSP1 complex. Depletion of ANXA6 in CAFs impaired complex formation and subsequently impaired PDA and metastasis occurrence, while injection of CAF-derived ANXA6+ EVs enhanced tumorigenesis. We found that the presence of ANXA6+ EVs in serum was restricted to PDA patients and represents a potential biomarker for PDA grade. These findings suggest that CAF-tumor cell crosstalk supported by ANXA6+ EVs is predictive of PDA aggressiveness, highlighting a therapeutic target and potential biomarker for PDA.

Cholesterol uptake disruption, in association with chemotherapy, is a promising combined metabolic therapy for pancreatic adenocarcinoma.

The malignant progression of pancreatic ductal adenocarcinoma (PDAC) is accompanied by a profound desmoplasia, which forces proliferating tumor cells to metabolically adapt to this new microenvironment. We established the PDAC metabolic signature to highlight the main activated tumor metabolic pathways. Comparative transcriptomic analysis identified lipid-related metabolic pathways as being the most highly enriched in PDAC, compared with a normal pancreas. Our study revealed that lipoprotein metabolic processes, in particular cholesterol uptake, are drastically activated in the tumor. This process results in an increase in the amount of cholesterol and an overexpression of the low-density lipoprotein receptor (LDLR) in pancreatic tumor cells. These findings identify LDLR as a novel metabolic target to limit PDAC progression. Here, we demonstrate that shRNA silencing of LDLR, in pancreatic tumor cells, profoundly reduces uptake of cholesterol and alters its distribution, decreases tumor cell proliferation, and limits activation of ERK1/2 survival pathway. Moreover, blocking cholesterol uptake sensitizes cells to chemotherapeutic drugs and potentiates the effect of chemotherapy on PDAC regression. Clinically, high PDAC Ldlr expression is not restricted to a specific tumor stage but is correlated to a higher risk of disease recurrence. This study provides a precise overview of lipid metabolic pathways that are disturbed in PDAC. We also highlight the high dependence of pancreatic cancer cells upon cholesterol uptake, and identify LDLR as a promising metabolic target for combined therapy, to limit PDAC progression and disease patient relapse.

Masked selection: a straightforward and flexible approach for the selection of binders against specific epitopes and differentially expressed proteins by phage display.

Phage display is a well-established procedure to isolate binders against a wide variety of antigens that can be performed on purified antigens, but also on intact cells. As selection steps are performed in vitro, it is possible to focus the outcome of the selection on relevant epitopes by performing some additional steps, such as depletion or competitive elutions. However in practice, the efficiency of these steps is often limited and can lead to inconsistent results. We have designed a new selection method named masked selection, based on the blockade of unwanted epitopes to favor the targeting of relevant ones. We demonstrate the efficiency and flexibility of this method by selecting single-domain antibodies against a specific portion of a fusion protein, by selecting binders against several members of the seven transmembrane receptor family using transfected HEK cells, or by selecting binders against unknown breast cancer markers not expressed on normal samples. The relevance of this approach for antibody-based therapies was further validated by the identification of four of these markers, Epithelial cell adhesion molecule, Transferrin receptor 1, Metastasis cell adhesion molecule, and Sushi containing domain 2, using immunoprecipitation and mass spectrometry. This new phage display strategy can be applied to any type of antibody fragments or alternative scaffolds, and is especially suited for the rapid discovery and identification of cell surface markers.

Cholecalciferol (vitamin D3) improves myelination and recovery after nerve injury.

Previously, we demonstrated i) that ergocalciferol (vitamin D2) increases axon diameter and potentiates nerve regeneration in a rat model of transected peripheral nerve and ii) that cholecalciferol (vitamin D3) improves breathing and hyper-reflexia in a rat model of paraplegia. However, before bringing this molecule to the clinic, it was of prime importance i) to assess which form - ergocalciferol versus cholecalciferol - and which dose were the most efficient and ii) to identify the molecular pathways activated by this pleiotropic molecule. The rat left peroneal nerve was cut out on a length of 10 mm and autografted in an inverted position. Animals were treated with either cholecalciferol or ergocalciferol, at the dose of 100 or 500 IU/kg/day, or excipient (Vehicle), and compared to unlesioned rats (Control). Functional recovery of hindlimb was measured weekly, during 12 weeks, using the peroneal functional index. Ventilatory, motor and sensitive responses of the regenerated axons were recorded and histological analysis was performed. In parallel, to identify the genes regulated by vitamin D in dorsal root ganglia and/or Schwann cells, we performed an in vitro transcriptome study. We observed that cholecalciferol is more efficient than ergocalciferol and, when delivered at a high dose (500 IU/kg/day), cholecalciferol induces a significant locomotor and electrophysiological recovery. We also demonstrated that cholecalciferol increases i) the number of preserved or newly formed axons in the proximal end, ii) the mean axon diameter in the distal end, and iii) neurite myelination in both distal and proximal ends. Finally, we found a modified expression of several genes involved in axogenesis and myelination, after 24 hours of vitamin supplementation. Our study is the first to demonstrate that vitamin D acts on myelination via the activation of several myelin-associated genes. It paves the way for future randomised controlled clinical trials for peripheral nerve or spinal cord repair.

Strengthened glycolysis under hypoxia supports tumor symbiosis and hexosamine biosynthesis in pancreatic adenocarcinoma.

Pancreatic ductal adenocarcinoma is one of the most intractable and fatal cancer. The decreased blood vessel density displayed by this tumor not only favors its resistance to chemotherapy but also participates in its aggressiveness due to the consequent high degree of hypoxia. It is indeed clear that hypoxia promotes selective pressure on malignant cells that must develop adaptive metabolic responses to reach their energetic and biosynthetic demands. Here, using a well-defined mouse model of pancreatic cancer, we report that hypoxic areas from pancreatic ductal adenocarcinoma are mainly composed of epithelial cells harboring epithelial-mesenchymal transition features and expressing glycolytic markers, two characteristics associated with tumor aggressiveness. We also show that hypoxia increases the "glycolytic" switch of pancreatic cancer cells from oxydative phosphorylation to lactate production and we demonstrate that increased lactate efflux from hypoxic cancer cells favors the growth of normoxic cancer cells. In addition, we show that glutamine metabolization by hypoxic pancreatic tumor cells is necessary for their survival. Metabolized glucose and glutamine converge toward a common pathway, termed hexosamine biosynthetic pathway, which allows O-linked N-acetylglucosamine modifications of proteins. Here, we report that hypoxia increases transcription of hexosamine biosynthetic pathway genes as well as levels of O-glycosylated proteins and that O-linked N-acetylglucosaminylation of proteins is a process required for hypoxic pancreatic cancer cell survival. Our results demonstrate that hypoxia-driven metabolic adaptive processes, such as high glycolytic rate and hexosamine biosynthetic pathway activation, favor hypoxic and normoxic cancer cell survival and correlate with pancreatic ductal adenocarcinoma aggressiveness.

Validation of an immunohistochemical signature predictive of 8-year outcome for patients with breast carcinoma.

We recently reported that standardized quantitative immunohistochemical (IHC) assays allowed prediction of an adverse outcome among 572 node negative (N-) patients with breast carcinoma (BrCa). To further validate our prior findings, we repeated the IHC stains including a second series of BrCa diagnosed at Yale University. Tissue microarrays (TMAs) of two cohorts of patients with BrCa (418 Marseille University and 303 Yale University) were respectively investigated for IHC expression of 15 markers (HIF-1α, PI3K, pAKT, pmTOR, moesin, P21, 4(E) BP-1, P27, Ker5-6, pMAPKAPK-2, SHARP2, claudin-1, ALDH, AF6 and CD24). Quantitative measurements of immunoprecipitates densitometry assessed with an image analyzer were correlated with 8-year patients' outcome and compared in the two cohorts. The best predictive signature consisted of a combination of five markers that included HIF-1α, PI3K, claudin-1, AF6 and pAKT in N- BrCa. This combination permitted an accurate prediction of outcome in 92.34% (386/418) of N- patients in the first set (Marseille) and 89.8% (158/176) in the second set (Yale). The close results in both cohorts confirmed the validity of this original IHC signature predictive of prognosis in node negative BrCa. This validation suggests that in clinical practice, it would be possible with standardized kits (i) to identify patients with poor prognosis at diagnosis time, particularly in the N- BrCa subset, who would require more aggressive adjuvant therapy and (ii) to avoid useless expensive therapies and their side effects in N- patients with favorable prognosis.

Immunohistochemical profiling of node negative breast carcinomas allows prediction of metastatic risk.

The aim of this study was to identify a prognostic immunohistochemical signature indicative of risk of early metastasis in node-negative breast carcinomas that would also be relevant to the development of new tailored therapy. Quantitative measurements of the immunohistochemical expression of 64 markers (selected from literature data) using high-throughput densitometry (as a continuous variable) of digitised microscopic micro-array images were correlated with clinical outcome in 667 node-negative breast carcinomas (mean follow-up 102 months). Multivariable fractional polynomials model of logistic regression allowed the selection of the best combination of markers (in terms of sensitivity and specificity) to predict patient outcome without any categorisation using predefined cut-points for individual marker measurements. A highly predictive ten-marker (out of 64) signature was identified comprising PI3K, pmTOR, pMAPKAPK-2, SHARP-2, P21, HIF-1alpha, Moesin, p4EBP-1, pAKT and P27 that well classified 91.4% of node-negative patients (specificity 90.9%, sensitivity 93.7%, area under ROC curve 0.958) independently of estrogen receptors (ER), and progesterone receptors (PR) and HER-2 status (91.6% well classified patients when ER, PR, HER-2 excluded). It is concluded that quantitative immunoprofiling of node-negative breast carcinomas is helpful in selecting patients who should not receive aggressive adjuvant chemotherapy and provides data for the development of tailored therapy.

Quantitative immunocytochemical profile to predict early outcome of disease in triple-negative breast carcinomas.

We aimed in this study at identifying prognostic immunohistochemical molecular signatures indicative of disease outcome, also relevant for development of new specific therapies, in triple-negative (ER, PR, c-erbB2- negative) breast carcinoma subtypes. We evaluated 42 markers in tissue micro-arrays from a series of 924 breast carcinomas including 184 triple-negative tumors using standardized quantitative immunocytochemical assays and correlated the data with patients' outcome (mean follow-up of 79 months). When 27/42 markers including basal-like markers first found to be individually significant for prognosis in a univariate analysis (log-rank test) in 924 tumors, were secondly evaluated in the triple-negative tumor subtype (184/924), eleven including maspin, P21, P27, PTEN, caveolin, EGFR, FAK, P38, pMAPK, STAT1 and CD10 were 89.2% predictive of disease outcome in logistic regression. When markers reported in the literature as expressed in basal-like subtype were evaluated in the 924 series, only eight (EGFR, CK14, moesin, caveolin, cMet, ckit, CD44v6, C10) were prognosis predictive in univariate analysis (log-rank test) and in logistic regression were predictive of disease outcome in 66.3% independently of ER, PR and c-erbB2 expression and in 72% in triple-negative tumor subset. The results suggest that the category of 'triple-negative' breast carcinomas does not exactly overlap the basal-like subtype, and that immunoprofiling of triple-negative tumors (not similar to that of basal-like tumors) may be helpful to select patients for more aggressive treatment and provides a basis for development of tailored therapy.

FK506 induces changes in muscle properties and promotes metabosensitive nerve fiber regeneration.

Accumulating evidence indicates that in addition to its immunosuppressant properties, FK506 (tacrolimus), an FDA-approved molecule, promotes nerve regeneration. However, the neuroprotective and neurotrophic effects of this molecule on sensitive fiber regeneration have never been studied. In order to fill this gap in our knowledge, we assessed the therapeutic potential of FK506 in a rat model of peripheral nerve repair. A 1-cm segment of left peroneal nerve was cut out and immediately autografted in an inverted position. After surgery, the animals were treated with FK506 (1.2 mg/kg/d) via an osmotic pump and compared to untreated animals. Recovery of use of the injured leg was assessed weekly for 12 weeks using a walking track apparatus and a camcorder. At the end of this period, motor and metabosensitive responses of the regenerated axons were recorded and histological analysis was performed. We observed that FK506 significantly: (1) increased the diameter of regenerated axons in the distal portion of the graft; (2) improved the responses of sensory neurons to metabolites such as potassium chloride and lactic acid; and (3) induced a fast-to-slow-fiber-type transition of the tibialis anterior muscle. Taken together, these data indicate that FK506 potentiates metabosensitive nerve fiber regeneration. Pharmacological studies of various dosages and concentrations of FK506 are required before recommending this drug for therapeutic treatment of nerve injuries.

A signature predictive of disease outcome in breast carcinomas, identified by quantitative immunocytochemical assays.

Quantitative immunocytochemical assays of 1,200 breast carcinomas were assessed after construction of tissue microarrays. A total of 42 markers were evaluated for prognostic significance by univariate log rank test (mean follow-up, 79 months), using quantitative scoring by an image analysis device and specific software. Complete data were obtained for 924 patients, for whom 27 of the 42 markers proved to be significant prognostic indicators. Analysis of these 27 markers by logistic regression showed that 18 (cMet, CD44v6, FAK, moesin, caveolin, c-Kit, CK14, CD10, P21, P27, pMAPK, pSTAT3, STAT1, SHARP2, FYN, ER, PgR and c-erb B2), and 15 when ER, PgR and c-erb B2 were excluded, were 80.52% and 78.9% predictive of disease outcome, respectively. The immunocytochemical assays on 4 micron thick sections of fixed tissue are easy to handle in current practice and are cost-effective. Quantitative densitometric measurement of immunoprecipitates by computer-assisted devices from digitized microscopic images allows standardized high-throughput "in situ" molecular profiling within tumors. It is concluded that this 15 marker immunohistochemical signature is suitable for current practice, since performed on paraffin sections of fixed tumor samples, and can be used to select patients needing more aggressive therapy, since this signature is about 80% predictive of poor clinical outcome. Also, the markers included in the signature may be indicative of tumor responsiveness to current chemotherapy or suggest new targets for specific therapies.

Functional recovery after peripheral nerve injury and implantation of a collagen guide.

Although surgery techniques improved over the years, the clinical results of peripheral nerve repair remain unsatisfactory. In the present study, we compare the results of a collagen nerve guide conduit to the standard clinical procedure of nerve autografting to promote repair of transected peripheral nerves. We assessed behavioral and functional sensori-motor recovery in a rat model of peroneal nerve transection. A 1cm segment of the peroneal nerve innervating the Tibialis anterior muscle was removed and immediately replaced by a new biodegradable nerve guide fabricated from highly purified type I+III collagens derived from porcine skin. Four groups of animals were included: control animals (C, n=12), transected animals grafted with either an autologous nerve graft (Gold Standard; GS, n=12) or a collagen tube filled with an acellular skeletal muscle matrix (Tube-Muscle; TM, n=12) or an empty collagen tube (Collagen-Tube; CT, n=12). We observed that 1) the locomotor recovery pattern, analyzed with kinetic parameters and peroneal functional index, was superior in the GS and CT groups; 2) a muscle contraction was obtained in all groups after stimulation of the proximal nerve but the mechanical muscle properties (twitch and tetanus threshold) parameters indicated a fast to slow fiber transition in all operated groups; 3) the muscular atrophy was greater in animals from TM group; 4) the metabosensitive afferent responses to electrically induced fatigue and to two chemical agents (KCl and lactic acid) was altered in GS, CT and TM groups; 5) the empty collagen tube supported motor axonal regeneration. Altogether, these data indicate that motor axonal regeneration and locomotor recovery can be obtained with the insertion of the collagen tube RevolNerv. Future studies may include engineered conduits that mimic as closely as possible the internal organization of uninjured nerve.

[Early breast carcinoma profiling based on quantitative immunocytochemistry can help predict the risk of early distant metastasis]. / Evaluation immunohistochimique du risque métastasique dans les cancers du sein débutants sur microbiopsies.

We examined a series of 667 patients with node-negative breast carcinomas in order to identify prognostic immunohistochemical molecular signatures for the prediction of early metastasis, and potential new therapeutic targets. We used a standardized quantitative immunocytochemical approach with 37 antibodies, based on high-throughput tissue microarrays and image analysis, and analyzed the results with respect to metastatic status after a mean follow-up of 86 months. Complete data were obtained for 586 patients. The predictive value of the markers was first analyzed individually by univariate analysis (log rank test) in 586 node-negative tumors, according to metastatic status during follow-up. Twenty-seven markers had significant prognostic value. ROC curve analysis (logistic regression) was then used to determine the marker combination that best classified the patients with and without metastases. A 15-marker signature (Bcl2, P16, P21, P27, P53, CD34, CA IX, c-kit, FGF-R1, P38, JAK, pSTAT3, CK9, STAT1 and ER) correctly classified 84.8% of the patients (sensitivity 85.5%, specificity 84.6%). When ER, PR and c-erb B2 were excluded from the analysis, a very similar signature, in which CK8-18 replaced ER, correctly classified 83.6% of the patients (sensitivity 84.5%, specificity 83.4%). These results show that quantitative immunoprofiling, independently of ER, PR and c-erb B2 status, can provide a basal-like signature, can properly predict the metastatic risk of node-negative breast carcinomas at diagnostic time. This may be helpful for selecting patients who do not need aggressive adjuvant chemotherapy, and for developing tailored therapies.

Vitamin D2 potentiates axon regeneration.

To date, the use of autograft tissue remains the "gold standard" technique for repairing transected peripheral nerves. However, the recovery is suboptimal, and neuroactive molecules are required. In the current study, we focused our attention on vitamin D, an FDA-approved molecule whose neuroprotective and neurotrophic actions are increasingly recognized. We assessed the therapeutic potential of ergocalciferol--the plant-derived form of vitamin D, named vitamin D2--in a rat model of peripheral nerve injury and repair. The left peroneal nerve was cut out on a length of 10 mm and immediately autografted in an inverted position. After surgery, animals were treated with ergocalciferol (100 IU/kg/day) and compared to untreated animals. Functional recovery of hindlimb was measured weekly, during 10 weeks post-surgery, using a walking track apparatus and a numerical camcorder. At the end of this period, motor and sensitive responses of the regenerated axons were calculated and histological analysis was performed. We observed that vitamin D2 significantly (i) increased axogenesis and axon diameter; (ii) improved the responses of sensory neurons to metabolites such as KCl and lactic acid; and (iii) induced a fast-to-slow fiber type transition of the Tibialis anterior muscle. In addition, functional recovery was not impaired by vitamin D supplementation. Altogether, these data indicate that vitamin D potentiates axon regeneration. Pharmacological studies with various concentrations of the two forms of vitamin D (ergocalciferol vs. cholecalciferol) are now required before recommending this molecule as a potential supplemental therapeutic approach following nerve injury.

[High-throughput quantification of tissue microarrays: identification of candidate target proteins in inflammatory breast cancer]. / La lecture automatisée à haut débit des micro-biopsies en pathologie: mise en évidence de la surexpression de c-Met et PI3K dans les cancers du sein inflammatoire.

Inflammatory breast carcinoma (IBC) is a rare but very aggressive tumour phenotype. Increased c-Met protein expression correlates with reduced survival and a higher metastatic risk in many human malignancies, including breast cancer Several studies have shown that c-Met protein is targetable by specific drugs. Here we compared c-Met expression in IBC (n = 41) and non IBC (n = 480). Two microarrays of IBC and non IBC tissues were constructed and standardized. C-Met, P13K and E-cadherin were immunodetected (Ven-tana Benchmark Autostainer) on serial sections. The results were quantified with an automated image analysis device (SAMBA Technologies) by immunoprecipitate densitometry of each core section (0.6 microns thick). We found that (i) c-Met is significantly overexpressed in IBC compared to non IBC (p < 0. 001), (ii) P13K is also overexpressed (p < 0.001) in IBC, suggesting that overexpressed c-Met is functionally active, at least through the PI3K signal transduction pathway ; and (iii) E-cadherin is paradoxically overexpressed in IBC. We conclude that c-Met may constitute a target for specific therapy in patients with poor-prognosis malignancies like IBC Automated image analysis of TMA is a valuable tool for high-throughput quantification of the immunohistochemical expression of the tumor proteome.

Overexpression of c-Met and of the transducers PI3K, FAK and JAK in breast carcinomas correlates with shorter survival and neoangiogenesis.

c-Met is responsible for cell motility and tumour spreading. c-Met expression and signal transducers reflecting c-Met functionality were investigated in breast carcinomas, in correlation with patient outcome and tumour vasculature. Tissue microarrays of 930 breast carcinomas were constructed, categorised according to patients' follow-up (4- to 10-year follow-up; median, 6.5 years). Standardised immunocytochemical procedures were performed using anti-c-Met, -PI3K, -FAK, -JAK, and -CD146, -FYN and an automated autostainer (Ventana). High-throughput densitometry measuring the extent of immunoprecipitates was assessed by image analysis (SAMBA). c-Met overexpression correlated with poor survival along with PI3K and FAK reflecting c-Met functionality and CD146 and FYN expression in endothelial cells. Automated quantification of immunocytochemical precipitates using image analysis was shown to provide an objective means of measuring cellular proteins that are potentially relevant for current practice in pathological diagnosis and for specific therapy combining inhibitors of both c-Met and downstream transducer pathways, and of tumour angiogenesis.

Poor prognosis in breast carcinomas correlates with increased expression of targetable CD146 and c-Met and with proteomic basal-like phenotype.

Genomic studies have led to new taxonomic classifications of breast carcinomas. Proteomic investigations using tissue microarrays have yielded complementary results and are useful in identifying potential molecular targets for specific therapies. Searching for new drug targets is particularly important for tumors of poor prognosis, such as breast tumors that lack estrogen receptors and HER2 amplification; in these tumors, certain molecules probably play a significant role in tumor spreading through the stromal microvasculature. We investigated 930 breast carcinomas categorized according to patients' survival (range of follow-up = 4-10 years; median follow-up = 6.5 years) using (1) automated immunohistochemical procedures (Ventana, Cedex, France) with tissue microarrays (Alphelys, Plaisir, France) and (2) quantification of immunoprecipitates assessed by automated image analysis densitometry (SAMBA, Meylan, France). Expression of c-Met and CD146 and that of signaling transducers PI3K, FAK, and FYN were compared in living and deceased patients. Expression of some proteins recently reported to be characteristic of basal cell carcinomas was also assessed, namely, CK5-6, caveolin-1, carbonic anhydrase IX, p63, and CD117; these also constitute potential targets for therapies for aggressive tumors. Overexpression of these proteins was observed in deceased or metastatic patients (P < .01 to P < .00001), particularly node-negative patients (except for FYN, p63, and CD146). c-Met and CD146 are involved in tumor spreading, and our results suggest that they probably play an important role in patients' death, along with other proteins involved in hypoxia (carbonic anhydrase IX) and other cell functions or structures (caveolin-1, CD117, CK5-6, and p63) that are expressed in an aggressive subtype of basal cell carcinoma for which no specific therapy is available.

Comparison of the prognosis indication of VEGFR-1 and VEGFR-2 and Tie2 receptor expression in breast carcinoma.

The degree of angiogenesis in breast cancer has previously been shown to be an indicator of prognosis, and tumor microvasculature is a candidate target for new antiangiogenic therapies. The aim of this study was to investigate the prognostic value of vascular endothelial growth factor (VEGF) receptors, VEGFR-1 (Flt-1) and VEGFR-2 (KDR/Flk-1), and Tie2/tek receptor tyrosine kinase in breast carcinoma. VEGF receptors and Tie2 expression was investigated using immunohistochemical assays with monoclonal antibodies on frozen sections in a series of 918 and 909 patients respectively. VEGFR-1 and VEGFR-2 and Tie2 were correlated with long-term (median, 11.3 years) patients' outcome. Univariate (Kaplan-Meier) analysis showed that VEGFR-1 positive tumor surface (cutoff = 5%) was significantly correlated with high metastasis risk (p=0.03) and relapse (p<0.01) in all patients, and in those with node negative tumors (p<0.001 and p<0.01 respectively), but not with overall survival. In contrast Tie2 positive tumor surface (cutoff = 7%) was significantly correlated with poor overall survival (p=0.025) and also with high metastasis risk particularly among node negative patients (p<0.01). Moreover, Tie2 immunoexpression was significantly predictive of relapse (p=0.003) in the node negative subgroup (p=0.02). In multivariate analysis (Cox model), VEGFR-1 and Tie2 immunoexpressions were identified as independent prognostic indicators. In contrast, univariate analysis showed that VEGFR-2 positive tumor surface (cutoff = 10%) was not correlated with survival or with metastasis and relapse risk. Our results suggest that VEGFR-1 and Tie2 immunohistochemical expression permits the identification of patients with poor outcome, and particularly node negative ones with a high risk for metastasis and relapse. VEGFR-1 and Tie2 immunodetection may also be considered as potential tools for selecting patients who could benefit in the future from specific antiangiogenic therapy interfering with VEGFR-1 and Tie2 activation pathways.

[Immunohistochemical expression of PTEN antigen: a new tool for diagnosis of early endometrial neoplasia]. / L'expression immunohistochimique de l'antigène PTEN: un nouvel outil diagnostique dans les néoplasies débutantes de l'endomètre.

We examined immunohistochemical PTEN protein expression in endometrial samples obtained from perimenopausal women with uterine bleeding in order to diagnose early endometrial neoplasia. Paraffin sections of endometrial samples (biopsies, endometrium resection, hysterectomy) were reviewed and tested for immunocytochemical PTEN expression by epithelial cells. Immunohistochemical studies were performed with the Ventana Benchmark device and the immunoperoxidase technique with monoclonal anti-PTEN (6H2.1/Cascade Biosciences). We studied 45 samples of proliferative endometria, 42 samples of atypical hyperplasia (neoplasia), and 55 samples of endometrial carcinomas (30 endometrioid, 5 serous papillary, 10 clear cell, 5 adenosquamous, and 5 MMMT). A strong positive PTEN immunoreaction was observed in all 45 normal proliferative endometria, 2/30 endometrioid carcinomas, and 23/25 non endometrioid carcinomas. In contrast, PTEN immunoexpression was negative or weak in 40/42 atypical hyperplasia and 28/30 endometrioid carcinomas. Negative or weak PTEN expression correlated with endometrial neoplasia (atypical proliferation) (p < 0.001). Thus (i) PTEN immunoexpression in endometrial paraffin sections is a new diagnostic tool, distinguishing PTEN-positive cyclic abnormal monoclonal proliferative endometrium (anovulatory, non atypical, simple and complex hyperplasia) from PTEN-negative (or decreased) endometrial neoplasia, and especially early endometrial neoplasia (atypical simple and complex hyperplasia, in situ carcinoma, superficial carcinoma with focal invasion). (ii) Given the lack of reproducibility of histological identification of atypical (precancerous invasive) and non atypical (precancerous non invasive) endometrial hyperplasia, the new criteria (PTEN-negative crowded glands, gland/stroma ratio > 55%, nuclear pleomorphism, in areas > 1 mm) recently proposed to diagnose early endometrial neoplasia appear to be clinically relevant.