Iloprost treatment summer-suspension: effects on skin thermal properties and cytokine profile in systemic sclerosis patients.

AIM: Aim of the study was to assess whether Iloprost treatment summer suspension modifies systemic cytokines levels, cutaneous thermal properties and functional response to a cold-induced stress in patients affected by systemic sclerosis (SSc). METHODS: Twenty-eight patients fulfilling the American College of Rheumatology (ACR) criteria for SSc were included in the study. Patients recorded number, duration and pain-severity of Raynaud phenomenon (RP). Pain-severity was determined by a visual analog scale. Cytokines expression and production in peripheral blood mononuclear cells and serum were evaluated by RT-PCR and ELISA assay. Basal finger temperature (Tb), distal-dorsal difference temperature (DTdd) and thermal recovery time (tr) from cold stress were measured by means of functional infrared imaging (fIR). Measurements were performed in late spring, during routine Iloprost therapy (1-3 days infusion of 0.5-2 ng/kg every month), and in late summer after a therapy-withdrawal period. RESULTS: Deterioration of SSc patients' skin thermal properties was observed in the period of therapy withdrawal (Tb reduction and tr enhancement; no DTdd differences) despite the improvement in symptoms of RP. A reduction in IL-12/23p40 gene expression was recorded after therapy withdrawal and a direct correlation between IL-12/23p40 and IL-23p19 gene expression was observed, stronger after therapy suspension. CONCLUSION: Our data suggest that Iloprost treatment summer suspension may induce the loss of the therapy beneficial effect on microcirculation despite the objective reduction of RP, thus favouring a continuous use of Iloprost in absence of severe side effects. Iloprost showed to modulate only IL-23 expression corroborating the idea that this cytokine is crucial for SSc development and progression.

An ErbB-3 antibody, MP-RM-1, inhibits tumor growth by blocking ligand-dependent and independent activation of ErbB-3/Akt signaling.

The ErbB receptors, such as ErbB-1 and ErbB-2, have been intensely pursued as targets for cancer therapeutics. Although initially efficacious in a subset of patients, drugs targeting these receptors led invariably to resistance, which is often associated with reactivation of the ErbB-3-PI3K-Akt signaling. This may be overcome by an ErbB-3 ligand that abrogates receptor-mediated signaling. Toward this end, we have generated a mouse monoclonal antibody, MP-RM-1, against the extracellular domain (ECD) of ErbB-3 receptor. Assessment of human tumor cell lines, as well as early passage tumor cells revealed that MP-RM-1 effectively inhibited both NRG-1ß-dependent and -independent ErbB-3 activation. The antagonizing effect of MP-RM-1 was of non-competitive type, as binding of [(125)I]-labeled NRG-1ß to ErbB-3 was not influenced by the antibody. MP-RM-1 treatment led, in most instances, to decreased ErbB-3 expression. In addition, MP-RM-1 was able to inhibit the colony formation ability of tumor cells and tumor growth in two human tumor xenograft nude mouse models. Treatment with the antibody was associated with a decreased ErbB-3 and Akt phosphorylation and ErbB-3 expression in the excised tumor tissue. Collectively, these results indicate that MP-RM-1 has the potential to interfere with signaling by ErbB-3 and reinforce the notion that ErbB-3 could be a key target in cancer-drug design.

Work stress and innate immune response.

Several reports highlight the relationship between blood NK cytotoxic activity and life style. Easy life style, including physical activity, healthy dietary habits as well as good mental health are characterized by an efficient immune response. Life style is related to the type of occupational activity since work has a central part in life either as source of income or contributing to represent the social identity. Not only occupational stress, but also job loss or insecurity are thus considered serious stressful situations, inducing emotional disorders which may affect both neuroendocrine and immune systems; reduced reactivity to mitogens and/or decreased blood NK cytotoxic activity was reported in unemployed workers or in those with a high perception of job insecurity and/or job stress. Although genetic factors have a key role in the pathogenesis of autoimmune disorders, occupational stress (as in night shifts) was reported associated to an increased incidence of autoimmune disorders. Monitoring blood NK response may thus be included in the health programs as an indirect index of stressful job and/or poor lifestyle.

Extremely low frequency electromagnetic fields modulate expression of inducible nitric oxide synthase, endothelial nitric oxide synthase and cyclooxygenase-2 in the human keratinocyte cell line HaCat: potential therapeutic effects in wound healing.

BACKGROUND: Extremely low frequency (ELF) electromagnetic fields (EMF) are known to produce a variety of biological effects. Clinical studies are ongoing using EMF in healing of bone fractures and skin wounds. However, little is known about the mechanisms of action of ELF-EMF. Several studies have demonstrated that expression and regulation of nitric oxide synthase (NOS) and cyclooxygenase-2 (COX-2) are vital for wound healing; however, no reports have demonstrated a direct action of ELF-EMF in the modulation of these inflammatory molecules in human keratinocytes. OBJECTIVES: The present study analysed the effect of ELF-EMF on the human keratinocyte cell line HaCaT in order to assess the mechanisms of action of ELF-EMF and to provide further support for their therapeutic use in wound healing. METHODS: Exposed HaCaT cells were compared with unexposed control cells. At different exposure times, expression of inducible NOS (iNOS), endothelial NOS (eNOS) and COX-2 was evaluated by Western blot analysis. Modulation of iNOS and eNOS was monitored by evaluation of NOS activities, production of nitric oxide (NO) and O(2)(-) and expression of activator protein 1 (AP-1). In addition, catalase activity and prostaglandin (PG) E(2) production were determined. Effects of ELF-EMF on cell growth and viability were monitored. RESULTS: The exposure of HaCaT cells to ELF-EMF increased iNOS and eNOS expression levels. These ELF-EMF-dependent increased expression levels were paralled by increased NOS activities, and increased NO production. In addition, higher levels of AP-1 expression as well as a higher cell proliferation rate were associated with ELF-EMF exposure. In contrast, ELF-EMF decreased COX-2 expression, PGE(2) production, catalase activity and O(2)(-) production. CONCLUSIONS: Mediators of inflammation, such as reactive nitrogen and PGE(2), and keratinocyte proliferation are critical for the tissue regenerative processes. The ability of ELF-EMF to upmodulate NOS activities, thus nitrogen intermediates, as well as cell proliferation, and to downregulate COX-2 expression and the downstream intermediate PGE(2), highlights the potential therapeutic role of ELF-EMF in wound healing processes.

Extremely low frequency electromagnetic field enhances human keratinocyte cell growth and decreases proinflammatory chemokine production.

BACKGROUND: Proliferation and differentiation of keratinocytes are central processes in tissue regeneration after injury. Chemokines, produced by a wide range of cell types including keratinocytes, play a regulatory role in inflammatory skin diseases. Several studies have shown that an electromagnetic field (EMF) can influence both inflammatory processes and repair mechanisms including wound healing on different tissue models. OBJECTIVES: To elucidate the effect of extremely low frequency EMF (ELF-EMF) on keratinocyte proliferation and production of chemokines [RANTES, monocyte chemoattractant protein (MCP)-1, macrophage inflammatory protein (MIP)-1 alpha and interleukin (IL)-8] in order to evaluate a potential therapeutic use of magnetic fields. METHODS: The human keratinocyte cell line HaCaT was exposed at 1 mT, 50 Hz for different lengths of time and compared with unexposed control cells. Cell growth and viability were evaluated at different exposure times by cell count and trypan blue exclusion. Chemokine production and expression were analysed by enzyme-linked immunosorbent assay (ELISA) and by real-time polymerase chain reaction. Total NF-kappaB p65 was quantified by ELISA. RESULTS: Significantly increased growth rates were observed after 48 h of EMF exposure as compared with control cells, while no difference in cell viabilities were detected. Gene expression and release of RANTES, MCP-1, MIP-1 alpha and IL-8 were significantly reduced after 72 h of exposure. NF-kappaB levels became almost undetectable after only 1 h of EMF exposure, and were inversely correlated with cell density. CONCLUSIONS: Our results show that ELF-EMF modulates chemokine production and keratinocyte growth through inhibition of the NF-kappaB signalling pathway and thus may inhibit inflammatory processes. ELF-EMF could represent an additional therapeutic approach in the treatment of skin injury.

Eosinophil recruiting chemokines are down-regulated in peripheral blood mononuclear cells of allergic patients treated with deflazacort or desloratadine.

Chemokines are cytokines with chemotactic properties on leukocyte subsets whose modulation plays a key role in allergic inflammatory processes. To better understand the possible anti-inflammatory effects of histamine-1 receptor antagonists in allergic asthma, we studied the mRNA expression of a set of chemokines known to be involved in the eosinophils-basophils activation as well as recruitment and T-cell signaling events, before and after corticosteroid or antihistamine treatment in PBMCs from allergic-asthmatic patients ex vivo. Twelve patients were enrolled, all of whom were allergic to Parietaria judaica and suffering for mild persistent asthma: six were treated with desloratadine (10 mg/day), and six with deflazacort (12 mg/day). Before and after the treatment, PBMC samples were collected from each patient and analyzed for the expression of encoding mRNAs for several chemokines, I-309 (CCL1), MCP-1 (CCL2), MIP1-alpha (CCL3), MIP1-beta (CCL4), RANTES (CCL5), IL-8 (CXCL8), IP-10 (CXCL10), Lymphotactin (XCL1). Clinical and functional improvements were seen after 3 weeks of therapy; this was associated with a reduced expression in the mRNA levels for the chemokines RANTES, MIP1-alpha and MIP1-beta with either the corticosteroid or the antihistamine, compared to the pre-treatment levels. Chemokine downregulation was statistically significant in both groups of patients. These findings suggest that certain antihistamines may act as down-modulators of allergic inflammation, possibly through a negative regulation of the chemokines involved in activation and attraction of eosinophils. Our results suggest that clinical trials with long follow-ups may be useful in evaluating histamine-1 receptor antagonists as add-on therapy to steroids in the treatment of asthma.

Expression of glycoprotein 90K in human malignant pleural mesothelioma: correlation with patient survival.

The expression of the tumour-associated glycoprotein 90K in patients with malignant pleural mesothelioma (MM) has not been described. This study used enzyme-linked immunoassay (ELISA) to measure 90K in pleural effusions (PEs) and sera from patients with MM (n=28), lung cancer (LC) (n=14) and benign pleural disease (BPD) (n=15). Immunohistochemistry was used to investigate 90K expression in MM and LC tissue sections. The expression of 90K was further evaluated in vitro by ELISA and western blot analysis of conditioned media and cellular extracts of MM, LC and normal human mesothelial (NHM) cell cultures. Finally, the relationships between 90K expression in MM and patient age and survival were studied. The mean 90K level was significantly higher (p<0.05) in PEs of MM patients (11.0+/-6.6 microg/ml) than in LC (6.1+/-3.2 microg/ml) or BPD (6.2+/-5.0 microg/ml) patients. Immunohistochemistry showed a positive reaction for 90K in MM biopsy sections and positive staining limited to inflammatory infiltrates in LC sections. The level of 90K was significantly higher in cell culture media of MM than of LC or NHM (p<0.001). Bands representing proteins with molecular weight of approximately 90 kDa were detected by western blot in MM cellular extracts. An inverse correlation between PE 90K levels and MM patient age (r=-0.45; p=0.017) and a positive correlation between serum 90K levels and MM patient survival (r=0.62; p=0.006) were detected by linear regression analysis. Kaplan-Meier univariate analysis showed increased survival probability for MM patients with serum 90K level >7.3 microg/ml (log rank, p<0.05). This is the first report in MM of the expression of 90K and of its potential diagnostic and prognostic application.

Co-localization of multiple ErbB receptors in stratified epithelium of oral squamous cell carcinoma.

The expression of all four ErbB receptors was compared by immunohistochemistry, using receptor-specific polyclonal antisera, in 32 invasive, 11 in situ carcinomas, six benign lesions, and 22 samples of histologically normal mucosa adjacent to specimens of carcinoma originating from oral cavity epithelium. Among invasive and in situ carcinoma, EGFR expression was the most prevalent (in 29/32 and 8/11 cases, respectively) followed by ErbB2 (17/32 and 2/11) and ErbB4 (9/32 and 1/10), while ErbB3 was only detected in invasive tumours (12/32). Specific patterns included invasive tumours with expression of EGFR (8/32) or ErbB4 (1/32) alone, as well as different receptor combinations (EGFR+ErbB2, EGFR+ErbB4, EGFR+ErbB2+ErbB3, EGFR+ErbB2+ErbB4, and all four receptors). Simultaneous expression of three or four ErbB receptors correlated with tumour invasion (p=2.2x10(-4)) and localized in the intermediate epithelial cell layer of well and moderately differentiated tumours. No other significant correlation with clinico-pathological features was noticed. Some benign lesions and histologically normal mucosa adjacent to carcinomas showed weak immunostaining of EGFR (10/28), ErbB2 (4/28) or ErbB4 (3/28). By comparison, overexpression, as indicated by increased staining intensity, was observed in invasive tumours for EGFR (18/32), ErbB2 (8/32), ErbB4 (3/32), and ErbB3 (3/32). Statistical evaluation demonstrated a significant association of EGFR or ErbB2 overexpression with invasive carcinoma when compared with benign lesions and apparently normal epithelium (p=5.2x10(-7) and p=5x10(-3), respectively). Tumour-specific overexpression of ErbB receptors and their co-expression, most frequently involving EGFR and ErbB2, in the same cell layer of neoplastic epithelium, implicate receptor heterodimers in the pathogenesis of oral squamous carcinoma.

Basic fibroblast growth factor in mesothelioma pleural effusions: correlation with patient survival and angiogenesis.

The expression of angiogenic factors may represent useful markers for diagnosis and prediction of disease outcome. Basic fibroblast growth factor (b-FGF) is a potent angiogenic factor which promotes in vitro growth of endothelial cells and in vivo vessel formation. We investigated the expression of b-FGF in patients affected with malignant and non-malignant pleural diseases and presenting clinically with non-specific signs and symptoms. We also studied the relationships between the expression of b-FGF in patients with malignant pleural mesothelioma (MM) and tumour aggressiveness, assessed as tumour vessel density (TVD), or patient survival. Basic-FGF was measured by immunoassay in the serum and pleural effusions (PE) of 37 patients. Of these, MM was diagnosed in 15/37 patients while the remaining patients had either peripheral lung adenocarcinoma (PLA) or benign inflammatory pleural disease (BPD). The mean b-FGF level measured 8.5+/-6.1 pg/ml in the PE of the malignant group (MM + PLA) and 23.9+/-19.8 in the PE of the non-malignant group (BPD) (p=0.001). The mean b-FGF level was significantly lower in the PE of MM patients (6.9+/-5.2 pg/ml) compared to BPD patients (p=0.004). Linear regression analysis showed a significant inverse correlation (r=-0.59; p=0.041) between b-FGF levels found in MM PE and patient survival. A noteworthy relationship between high serum b-FGF levels and reduced survival was also observed (r=-0.57; p=0.052). Interestingly, both serum (r=0.48; p=0.114) and PE (r=0.26; p=0.413) b-FGF levels in MM patients correlated poorly with TVD. Our data indicate that b-FGF is significantly more expressed in non-malignant compared to malignant PE, this difference being particularly evident between MM and BPD. Our results also suggest that high b-FGF levels correlate with poor MM patient survival through mechanisms which may be independent of b-FGF angiogenic potential.

ErbB2 immune response in breast cancer patients with soluble receptor ectodomain.

Investigation of ErbB2 immunity in human breast cancer employing recombinant expression sources in immunoblot analysis revealed ErbB2-specific antibodies of the IgG isotype in sera of 14 of 71 cancer patients and 1 of 31 normal donors. Reactivity was confirmed on ErbB2-specific immunoprecipitates. Independent evidence of existing ErbB2 immunity was obtained after in vitro transformation of peripheral blood leukocytes from six positive patients. Furthermore, in vitro immortalization of B-lymphocytes unmasked existent ErbB2 immunity in 1 of 8 patients negative for ErbB2 serum antibodies. Determining shed ErbB2 extracellular domain as an indirect measure of tumor burden in ErbB2-positive malignancy, elevated serum levels were observed in 16 of 71 breast cancer and 1 of 31 normal donor sera. Strikingly, existing ErbB2 immunity correlated significantly with elevated shed ErbB2 ectodomain among the patients analyzed. Incidence of both ErbB2 immunity and elevated ErbB2 extracellular domain increased with a progressed disease stage and was significantly associated with metastatic breast cancer. These observations implicate soluble ErbB2 amounts in vivo in the development of ErbB2 immunity in breast cancer. They further project serum analysis of ErbB2 immunity and soluble ectodomain as potential markers of disease progression in ErbB2-positive malignancy.

The BFRF1 gene of Epstein-Barr virus encodes a novel protein.

Computer analysis of the Epstein-Barr virus (EBV) genome indicates there are approximately 100 open reading frames (ORFs). Thus far about 30 EBV genes divided into the categories latent and lytic have been identified. The BamHI F region of EBV is abundantly transcribed during lytic replication. This region is highly conserved among herpesviruses, thus suggesting that some common function could be retained in the ORFs encompassed within this viral fragment. To identify putative novel proteins and possible new markers for viral replication, we focused our attention on the first rightward ORF in the BamHI F region (BFRF1). Histidine and glutathione S-transferase-tagged BFRF1 fusion proteins were synthesized to produce a mouse monoclonal antibody (MAb). Analysis of human sera revealed a high seroprevalence of antibodies to BFRF1 in patients affected by nasopharyngeal carcinoma or Burkitt's lymphoma, whereas no humoral response to BFRF1 could be detected among healthy donors. An anti-BFRF1 MAb recognizes a doublet migrating at 37 to 38 kDa in cells extracts from EBV-infected cell lines following lytic cycle activation and in an EBV-negative cell line (DG75) transfected with a plasmid expressing the BFRF1 gene. Northern blot analysis allowed the detection of a major transcript of 3.7 kb highly expressed in EBV-positive lytic cycle-induced cell lines. Treatment with inhibitors of viral DNA polymerase, such as phosphonoacetic acid and acyclovir, reduced but did not abolish the transcription of BFRF1, thus indicating that BFRF1 can be classified as an early gene. Cell fractionation experiments, as well as immunolocalization by immunofluorescence microscopy, immunohistochemistry, and immunoelectron microscopy, showed that BFRF1 is localized on the plasma membrane and nuclear compartments of the cells and is a structural component of the viral particle. Identification of BFRF1 provides a new marker with which to monitor EBV infection and might help us better understand the biology of the virus.

Cryptic epitopes on alpha-fetoprotein induce spontaneous immune responses in hepatocellular carcinoma, liver cirrhosis, and chronic hepatitis patients.

To determine alpha-fetoprotein (AFP) immunogenicity in vivo, the presence of antibodies in sera of 60 hepatocellular carcinoma, 15 liver cirrhosis, and 15 chronic hepatitis patients was evaluated by Western blotting and immunoprecipitation analyses using purified human AFP. High titers of anti-AFP immunoglobulins were detected in 14 hepatocellular carcinomas (P = 0.0006), 3 liver cirrhosis (P = 0.0173), and 1 chronic hepatitis patient, but they were not detected in 40 healthy individuals. Therefore, spontaneous immune responses to AFP are significantly associated to liver diseases (P = 0.0015). Patient immunoglobulins recognized proteic linear epitopes that were cryptic in the native protein, as demonstrated by their restricted reactivity with denatured deglycosylated AFP. Thus, in pathological liver conditions, tolerance to this self-molecule is circumvented. The identification of AFP immunogenic epitopes may contribute to defining novel immunotherapeutic strategies targeting this antigen.

TAG-72 expression and clinical outcome in primary breast cancer.

Clinical data of 92 patients with primary breast carcinomas previously analysed for the pattern of immunohistochemical expression of three distinct carbohydrate epitopes of the TAG-72 molecule were reviewed. The clinical outcome of the patients after a median follow-up of 66 months was determined in 84 out of 92 patients. Clinicopathological characteristics of the tumours and clinical outcome of the patients were correlated with the TAG-72 epitope expression. TAG-72 was expressed more frequently in patients aged more than 50 years and in tumours of larger size, with lymph nodes metastasis, with low differentiation and with high proliferative activity. A statistical correlation was found with more advanced stages of the disease (35.7% vs 60% in stage I and in stage II-III, respectively, p=0.03). Disease-free survival and overall survival were estimated by the Kaplan-Meier method. The survival of the patients with tumours expressing TAG-72 was not statistically different from that of patients with tumours without TAG-72 expression. These data suggest that TAG-72 expression is associated with clinicopathological parameters of aggressiveness in primary breast cancer, but it does not appear to affect the clinical outcome of the patients.

Expression of keratinocyte growth factor receptor compared with that of epidermal growth factor receptor and erbB-2 in endometrial adenocarcinoma.

Immunohistochemical analysis of the expression of keratinocyte growth factor receptor (KGFR) was performed in human endometrial carcinomas from 18 patients and in normal proliferative and secretory endometrium. The level of immunostaining was correlated with the clinico-pathological characteristics of the endometrial carcinoma patients and with the parallel expression of the epidermal growth factor receptor (EGFR) and erbB-2. The results showed that KGFR expression increased with the stage of the tumor and that the simultaneous overexpression of the three growth factor receptors appeared to be related to the depth of myometrial invasion. Taken together, these observations suggest that KGFR may represent an additional prognostic indicator in endometrial cancer.

Immune responses to all ErbB family receptors detectable in serum of cancer patients.

Employing NIH3T3 transfectants with individual human ErbB receptor coding sequences as recombinant antigen sources, we detected by immunoblot analysis specific immunoreactivity against all four ErbB receptors among 13 of 41 sera obtained from patients with different types of epithelial malignancies. Overall, serum positivity was most frequently directed against ErbB2 followed by EGFR, ErbB3 and ErbB4. Specificity patterns comprised tumor patients with unique serum reactivity against ErbB2 or ErbB4. Moreover, approximately half of the positive sera exhibited concomitant reactivity with multiple ErbB receptors including EGFR and ErbB2, EGFR and ErbB4, ErbB2 and ErbB3 or EGFR, ErbB2 and ErbB3. Serum reactivity was confirmed for the respective ErbB receptors expressed by human tumor cells and corroborated on receptor-specific immunoprecipitates. Positive sera contained ErbB-specific antibodies of the IgG isotype. Representative immunohistochemical analysis of tumor tissues suggested overexpression of ErbB receptors for which serum antibodies were detectable in five of six patients. These findings implicate multiple ErbB receptors including ErbB3 and ErbB4 in addition to EGFR and ErbB2 in primary human cancer. Heterogeneity of natural ErbB-specific responses in cancer patients warrants their evaluation in light of immunotherapeutic approaches targeting these receptors.

The use of a cationic liposome formulation (DOTAP) mixed with a recombinant tumor-associated antigen to induce immune responses and protective immunity in mice.

The cationic liposome DOTAP is a well-known transfection reagent. It has been manufactured and approved for clinical use, is readily available, and can be easily used as an adjuvant. These characteristics prompted us to investigate the effectiveness of DOTAP as an adjuvant to induce immune responses and protective immunity in mice using baculovirus-derived carcinoembryonic antigen (bV-CEA) as a model antigen. Two routes of administration and a dose-response study of bV-CEA were used in BALB/c mice to define the magnitude of the immune response as well as the most effective route of immunization. The results demonstrate differences in antibody titers, immunoglobulin (Ig)G isotype, and T-cell responses between the intravenous (i.v.) or subcutaneous (s.c.) route of immunization. The titer of the anti-CEA antibodies induced by the s.c. immunization was greater than the response by i.v. immunization. The s.c. route enhanced the IgG2a/2b isotype, whereas i.v. immunization elicited primarily IgG1. T-cell proliferation responses and cytokine production paralleled the humoral response (i.e., production was higher in the s.c. immunized animals). No differences in immunological responses were seen using either 25 or 10 microg of bV-CEA three times. An amount of 25 microg of bV-CEA/DOTAP given by s.c. immunization was sufficient in protecting mice from the transplant of syngeneic tumor cells transduced with the human CEA gene. We conclude that the cationic liposome DOTAP may be a useful immunoadjuvant for active anti-tumor immunotherapy in future clinical trials. This study will help to define the most effective way to use such an adjuvant.

Analysis of p53 expression in precancerous and malignant gastric mucosa.

P53 overexpression, detected by immunohistochemical analysis, has been reported in about 50% of gastric cancers whereas scarce data are available on the p53 oncoprotein in precancerous gastric lesions. This study focused on the p53 expression in gastric cancerous and precancerous lesions. One hundred gastric specimens obtained during endoscopy were analyzed: 14 cases of normal gastric mucosa, 53 of chronic gastritis with intestinal metaplasia and/or dysplasia and 33 gastric tumors. An immunoperoxidase technique and monoclonal anti-p53 antibodies were employed. Eleven out of 31 gastric carcinomas overexpressed p53. No correlation was observed between p53-positivity and histological type and grade of tumors. All precancerous lesions were p53-negative. Our results suggest that p53 overexpression is a relatively late event in gastric carcinogenesis.

Cell mediated cytotoxicity of human colon carcinoma cells by a monoclonal antibody (R4) recognizing the carcinoembryonic antigen (CEA) and CEA-related molecules.

We report a novel anti-CEA monoclonal antibody (MAb) designated R4, which mediates antibody-dependent cell-mediated cytotoxicity (ADCC) of human colon carcinoma cells and displays differential reactivity for human carcinomas versus the normal counterparts. R4 (IgG1) reacted with the cell surface of 6 colon carcinoma cell lines expressing CEA. Western blot analysis and epitope mapping using native and baculovirus recombinant CEA and non specific cross-reacting antigen (NCA) demonstrated that MAb R4 recognizes a proteinic epitope located on the 3' end of the domain I shared by CEA and NCA molecules. Immunohistochemical analysis demonstrated an intense staining of MAb R4 with the majority of the neoplastic tissues tested, including colon (13/13), stomach (2/2), breast (9/10), lung (7/10) and endometrial (2/4) carcinomas, whereas no reactivity with the correspondent normal tissues was observed. Using human PBLs from healthy donors as effector cells, we have shown that MAb R4 mediated antibody dependent-cell mediated cytotoxicity (ADCC) of human carcinoma cells LS-174T, CBS and WiDr. This activity was enhanced after PBLs activation with interleukin-2 (IL-2). The specificity of MAb R4 for an epitope shared by two tumor overexpressed antigens, CEA and NCA, resulting in an intense reactivity with neoplastic cells and the peculiar property to mediate ADCC, indicate that MAb R4 might be a novel powerful reagent for diagnostic and immunotherapy of carcinoma patients.

Immunohistochemical analysis of epidermal growth factor receptor (EGF-R) and c-erbB-2 and correlation with pathological prognostic variables in endometrial carcinomas.

In this study the immunohistochemical expressions of epidermal growth factor receptor (EGF-R) and erbB-2 in endometrial carcinomas at different stages of disease progression were evaluated and correlated with clinicopathological prognostic variables. Our results indicate that EGF-R and erbB-2 molecules are expressed in normal endometrium as well as in the majority of the carcinomas evaluated (83% and 92% respectively). The intensity of the immunostaining varied greatly (1+ to 3+) in the different tumors. Within these tumors we focused on those characterized by high levels of expression (i.e. overexpression). Expression and overexpression of EGF-R has been associated with poorly differentiated tumors and with a 3.3 times higher risk of a more rapid disease relapse. Overexpression of the erbB-2 oncoprotein was significatively correlated with depth of myometrial invasion (M0-M1 vs M2-M3 p=0.05), pathological stage (stage I vs II-IV p=0.02) and grade of tumor differentiation (G1 vs G2-G3 p=0.001). In particular, c-erbB-2 overexpression was able to discriminate between the different subsets of stage I carcinomas. None of the IA tumors overexpressed the oncoprotein, as compared to IB and IC (41% and 100% respectively, p=0.04). This finding highlights a role for erbB-2 protein as a prognostic parameter in stage I endometrial carcinoma patients.