Repeated pancreatic resection for pancreatic metastases from renal cell Carcinoma: A Spanish multicenter study (PANMEKID).

BACKGROUND AND OBJECTIVES: Recurrent isolated pancreatic metastasis from Renal Cell Carcinoma (RCC) after pancreatic resection is rare. The purpose of our study is to describe a series of cases of relapse of pancreatic metastasis from renal cancer in the pancreatic remnant and its surgical treatment with a repeated pancreatic resection, and to analyse the results of both overall and disease-free survival. METHODS: Multicenter retrospective study of patients undergoing pancreatic resection for RCC pancreatic metastases, from January 2010 to May 2020. Patients were grouped into two groups depending on whether they received a single pancreatic resection (SPS) or iterative pancreatic resection. Data on short and long-term outcome after pancreatic resection were collected. RESULTS: The study included 131 pancreatic resections performed in 116 patients. Thus, iterative pancreatic surgery (IPS) was performed in 15 patients. The mean length of time between the first pancreatic surgery and the second was 48.9 months (95 % CI: 22.2-56.9). There were no differences in the rate of postoperative complications. The DFS rates at 1, 3 and 5 years were 86 %, 78 % and 78 % vs 75 %, 50 % and 37 % in the IPS and SPS group respectively (p = 0.179). OS rates at 1, 3, 5 and 7 years were 100 %, 100 %, 100 % and 75 % in the IPS group vs 95 %, 85 %, 80 % and 68 % in the SPS group (p = 0.895). CONCLUSION: Repeated pancreatic resection in case of relapse of pancreatic metastasis of RCC in the pancreatic remnant is justified, since it achieves OS results similar to those obtained after the first resection.

Multinational Prospective Cohort Study of Mortality Risk Factors in 198 ICUs of 12 Latin American Countries over 24 Years: The Effects of Healthcare-Associated Infections.

BACKGROUND: The International Nosocomial Infection Control Consortium (INICC) has found a high ICU mortality rate in Latin America. METHODS: A prospective cohort study in 198 ICUs of 96 hospitals in 46 cities in 12 Latin American countries to identify mortality risk factors (RF), and data were analyzed using multiple logistic regression. RESULTS: Between 07/01/1998 and 02/12/2022, 71,685 patients, followed during 652,167 patient-days, acquired 4700 HAIs, and 10,890 died. We prospectively collected data of 16 variables. Following 11 independent mortality RFs were identified in multiple logistic regression: ventilator-associated pneumonia (VAP) acquisition (adjusted odds ratio [aOR] = 1.17; 95% CI: 1.06-1.30; p < 0.0001); catheter-associated urinary tract infection (CAUTI) acquisition (aOR = 1.34; 95% CI: 1.15-1.56; p < 0.0001); older age, rising risk 2% yearly (aOR = 1.02; 95% CI: 1.01-1.02; p < 0.0001); longer indwelling central line(CL)-days, rising risk 3% daily (aOR = 1.03; 95% CI: 1.02-1.03; p < 0.0001); longer indwelling urinary catheter(UC)-days, rising risk 1% daily (aOR = 1.01; 95% CI: 1.01-1.26; p < 0.0001); higher mechanical ventilation (MV) (aOR = 6.47; 95% CI: 5.96-7.03; p < 0.0001) and urinary catheter-utilization ratio (aOR = 1.19; 95% CI: 1.11-1.27; p < 0.0001); lower-middle level income country (aOR = 2.94; 95% CI: 2.10-4.12; p < 0.0001); private (aOR = 1.50; 95% CI: 1.27-1.77; p < 0.0001) or public hospital (aOR = 1.47; 95% CI: 1.24-1.74; p < 0.0001) compared with university hospitals; medical hospitalization instead of surgical (aOR = 1.67; 95% CI: 1.59-1.75; p < 0.0001); neurologic ICU (aOR = 4.48; 95% CI: 2.68-7.50; p < 0.0001); adult oncology ICU (aOR = 3.48; 95% CI: 2.14-5.65; p < 0.0001); and others. CONCLUSION: Some of the identified mortality RFs are unlikely to change, such as the income level of the country, facility ownership, hospitalization type, ICU type, and age. But some of the mortality RFs we found can be changed, and efforts should be made to reduce CL-days, UC-days, MV-utilization ratio, UC-utilization ratio, and lower VAPs and CAUTI rates.

Pancreatic metastases from renal cell carcinoma. Postoperative outcome after surgical treatment in a Spanish multicenter study (PANMEKID).

BACKGROUND: Renal Cell Carcinoma (RCC) occasionally spreads to the pancreas. The purpose of our study is to evaluate the short and long-term results of a multicenter series in order to determine the effect of surgical treatment on the prognosis of these patients. METHODS: Multicenter retrospective study of patients undergoing surgery for RCC pancreatic metastases, from January 2010 to May 2020. Variables related to the primary tumor, demographics, clinical characteristics of metastasis, location in the pancreas, type of pancreatic resection performed and data on short and long-term evolution after pancreatic resection were collected. RESULTS: The study included 116 patients. The mean time between nephrectomy and pancreatic metastases' resection was 87.35 months (ICR: 1.51-332.55). Distal pancreatectomy was the most performed technique employed (50 %). Postoperative morbidity was observed in 60.9 % of cases (Clavien-Dindo greater than IIIa in 14 %). The median follow-up time was 43 months (13-78). Overall survival (OS) rates at 1, 3, and 5 years were 96 %, 88 %, and 83 %, respectively. The disease-free survival (DFS) rate at 1, 3, and 5 years was 73 %, 49 %, and 35 %, respectively. Significant prognostic factors of relapse were a disease free interval of less than 10 years (2.05 [1.13-3.72], p 0.02) and a history of previous extrapancreatic metastasis (2.44 [1.22-4.86], p 0.01). CONCLUSIONS: Pancreatic resection if metastatic RCC is found in the pancreas is warranted to achieve higher overall survival and disease-free survival, even if extrapancreatic metastases were previously removed. The existence of intrapancreatic multifocal compromise does not always warrant the performance of a total pancreatectomy in order to improve survival.

Discovery of tight-binding competitive inhibitors of dipeptidyl peptidase IV.

Dipeptidyl peptidase IV (DPP-IV, EC 3.4.14.5) is an abundant serine aminopeptidase that preferentially cleaves N-terminal Xaa-Pro or Xaa-Ala dipeptides from oligopeptides. Inhibitors of DPP-IV activity are used for treating type 2 diabetes mellitus and other diseases. DPP-IV is also involved in tumor progression. We identified four new non-peptide tight-binding competitive inhibitors of porcine DPP-IV by virtual screening and enzymatic assays. Molecular docking simulations supported the competitive behavior, and the selectivity of one of the compounds in the DPP-IV family. Since three of these inhibitors are also aminopeptidase N (APN) inhibitors, we tested their impact on APN+/DPP-IV+ and DPP-IV+ human tumor cells' viability. Using kinetic assays, we determined that HL-60 tumor cells express both APN and DPP-IV activities and that MDA-MB-231 tumor cells express DPP-IV activity. The inhibitors had a slight inhibitory effect on human HEK-293 cell viability but reduced the viability of APN+/DPP-IV+ and DPP-IV+ human tumor cells more potently. Remarkably, the intraperitoneal injection of these compounds inhibited DPP-IV activity in rat brain, liver, and pancreas. In silico studies suggested inhibitors binding to serum albumin contribute to blood-brain barrier crossing. The spectrum of action of some of these compounds may be useful for niche applications.

Bacitracin is a non-competitive inhibitor of porcine M1 family neutral and glutamyl aminopeptidases.

Membrane alanyl and glutamyl aminopeptidases (APN and APA, respectively) are established targets for the development of biomedical tools in human pathologies. APN overexpression correlates with the progression of tumours, including melanoma. Bacitracin, widely used as a topical antibiotic, inhibits subtilisin-like serine peptidases and disulphide isomerases. In the present contribution, we demonstrate that bacitracin is a non-competitive α = 1 and α < 1 inhibitor of porcine kidney APN and APA, respectively, with Ki values in the micromolar range. To test a potential application of this result, we assayed the effect of bacitracin on murine melanoma MB16F10 cell line viability. We demonstrated the cell line expresses an APN-like activity inhibited by bacitracin and bestatin. Additionally, we identified a cytotoxic effect of bacitracin. Further experiments are required to understand in depth the mechanisms of action of bacitracin on melanoma cells. They will clarify the therapeutic potential of bacitracin for melanoma treatment.

Bestatin and bacitracin inhibit porcine kidney cortex dipeptidyl peptidase IV activity and reduce human melanoma MeWo cell viability.

Bestatin and bacitracin are inhibitors of metallo aminopeptidases and bacterial proteases. However, their effects on other human peptidases, like dipeptidyl peptidase IV (DPP-IV, EC 3.4.14.5) are not established. Inhibitors of DPP-IV activity are used for treating type 2 diabetes mellitus, cancers and immune system diseases. Bacitracin and bestatin inhibited porcine membrane-bound DPP-IV (pDPP-IV) activity. Mechanisms were different, i.e. non-competitive with α > 1 (α = 3.9) and Ki value of 75 µM for bestatin, and competitive with Ki value of 630 µM for bacitracin. The binding mode in the tertiary complex enzyme:substrate:bestatin suggested the structural basis of the inhibitory effect and that bestatin is potentially selective for DPP-IV, ineffective vs. S9 family members dipeptidyl peptidase 8/9 and fibroblast activation protein. In the human melanoma MeWo cell line, bestatin and bacitracin inhibited aminopeptidase N (APN) and DPP-IV activities, reduced cell viability and increased DNA fragmentation, suggesting induction of apoptosis. Since bacitracin and bestatin are already marketed drugs, studying in depth the molecular mechanisms underlying their effects on melanoma cells is warranted. Additionally, bestatin emerges as a new lead compound for the development of DPP-IV inhibitors, and a promising dual APN/DPP-IV inhibitor for the treatment of pathologies in which both enzymes are upregulated.

Targeting HER3, a Catalytically Defective Receptor Tyrosine Kinase, Prevents Resistance of Lung Cancer to a Third-Generation EGFR Kinase Inhibitor.

Although two growth factor receptors, EGFR and HER2, are amongst the best targets for cancer treatment, no agents targeting HER3, their kinase-defective family member, have so far been approved. Because emergence of resistance of lung tumors to EGFR kinase inhibitors (EGFRi) associates with compensatory up-regulation of HER3 and several secreted forms, we anticipated that blocking HER3 would prevent resistance. As demonstrated herein, a neutralizing anti-HER3 antibody we generated can clear HER3 from the cell surface, as well as reduce HER3 cleavage by ADAM10, a surface metalloproteinase. When combined with a kinase inhibitor and an anti-EGFR antibody, the antibody completely blocked patient-derived xenograft models that acquired resistance to EGFRi. We found that the underlying mechanism involves posttranslational downregulation of HER3, suppression of MET and AXL upregulation, as well as concomitant inhibition of AKT signaling and upregulation of BIM, which mediates apoptosis. Thus, although HER3 is nearly devoid of kinase activity, it can still serve as an effective drug target in the context of acquired resistance. Because this study simulated in animals the situation of patients who develop resistance to EGFRi and remain with no obvious treatment options, the observations presented herein may warrant clinical testing.

Results of a survey on peri-operative nutritional support in pancreatic and biliary surgery in Spain.

INTRODUCTION: Introduction: a survey on peri-operative nutritional support in pancreatic and biliary surgery among Spanish hospitals in 2007 showed that few surgical groups followed the 2006 ESPEN guidelines. Ten years later we sent a questionnaire to check the current situation. Methods: a questionnaire with 21 items sent to 38 centers, related to fasting time before and after surgery, nutritional screening use and type, time and type of peri-operative nutritional support, and number of procedures. Results: thirty-four institutions responded. The median number of pancreatic resections (head/total) was 29.5 (95% CI: 23.0-35; range, 5-68) (total, 1002); of surgeries for biliary malignancies (non-pancreatic), 9.8 (95% CI: 7.3-12.4; range, 2-30); and of main biliary resections for benign conditions, 10.4 (95% CI: 7.6-13.3; range, 2-33). Before surgery, only 41.2% of the sites used nutritional support (< 50% used any nutritional screening procedure). The mean duration of preoperative fasting for solid foods was 9.3 h (range, 6-24 h); it was 6.6 h for liquids (range, 2-12). Following pancreatic surgery, 29.4% tried to use early oral feeding, but 88.2% of the surveyed teams used some nutritional support; 26.5% of respondents used TPN in 100% of cases. Different percentages of TPN and EN were used in the other centers. In malignant biliary surgery, 22.6% used TPN always, and EN in 19.3% of cases. Conclusions: TPN is the commonest nutrition approach after pancreatic head surgery. Only 29.4% of the units used early oral feeding, and 32.3% used EN; 22.6% used TPN regularly after surgery for malignant biliary tumours. The 2006 ESPEN guideline recommendations are not regularly followed 12 years after their publication in our country.

INTRODUCCIÓN: Introducción: realizamos una encuesta sobre soporte nutricional perioperatorio en cirugía pancreática y biliar en hospitales españoles en 2007, que mostró que pocos grupos quirúrgicos seguían las guías de ESPEN 2006. Diez años después enviamos un cuestionario para comprobar la situación actual. Métodos: treinta y ocho centros recibieron un cuestionario con 21 preguntas sobre tiempo de ayunas antes y después de la cirugía, cribado nutricional, duración y tipo de soporte nutricional perioperatorio, y número de procedimientos. Resultados: respondieron 34 grupos. La mediana de pancreatectomías (cabeza/total) fue de 29,5 (IC 95%: 23,0-35; rango, 5-68) (total, 1002), la de cirugías biliares malignas de 9,8 (IC 95%: 7,3-12,4; rango, 2-30) y la de resecciones biliares por patología benigna de 10,4 (IC 95%: 7,6-13,3; rango, 2-33). Solo el 41,2% de los grupos utilizaban soporte nutricional antes de la cirugía (< 50% habian efectuado un cribado nutricional). El tiempo medio de ayuno preoperatorio para sólidos fue de 9,3 h (rango, 6-24 h), y de 6,6 h para líquidos (rango, 2-12). Tras la pancreatectomía, el 29,4% habían intentado administrar una dieta oral precoz, pero el 88,2% de los grupos usaron algún tipo de soporte nutricional y el 26,5% usaron NP en el 100% de los casos. Los demás grupos usaron diferentes porcentajes de NP y NE en sus casos. En la cirugía biliar maligna, el 22,6% utilizaron NP siempre y NE en el 19,3% de los casos. Conclusiones: la NP es el soporte nutricional más utilizado tras la cirugía de cabeza pancreática. Solo el 29,4% de las unidades usan nutrición oral precoz y el 32,3% emplean la NE tras este tipo de cirugía. El 22,6% de las instituciones usan NP habitualmente tras la cirugía de tumores biliares malignos. Las guías ESPEN 2006 no se siguen de forma habitual en nuestro país tras más de 10 años desde su publicación.

Nimotuzumab: beyond the EGFR signaling cascade inhibition.

One of the most known oncogenes is the epidermal growth factor receptor (EGFR) family. It activates multiple signaling cascades that promote carcinogenesis and immune evasion. Therefore, these molecules have been extensively targeted in cancer immunotherapy. Beyond EGFR signaling cascade inhibition, some of these agents are able to induce T-cell activation, transforming a passive therapy into a vaccine-like effect. Nimotuzumab is an IgG1 humanized monoclonal antibody directed against the extracellular domain of the EGFR blocking the binding to its ligands. It possesses unique pharmacodynamic properties, which allow treating patients for long-term periods and with very low toxicity. Based on its clinical effect, nimotuzumab has been approved in Cuba and abroad for the treatment of different epithelial tumors. Recently, new potential mechanisms of action of nimotuzumab involving the activation of the innate and adaptive immune response have been reported. This review summarizes the main properties of nimotuzumab in comparison with other EGFR-specific monoclonal antibodies, highlighting its capacity to activate an effective immune response. In addition, differential clinical effects of this antibody and ongoing clinical trials to deeply characterize the biomarkers of clinical benefit are shown.

Safety and Immunogenicity of a Human Epidermal Growth Factor Receptor 1 (HER1)-Based Vaccine in Prostate Castration-Resistant Carcinoma Patients: A Dose-Escalation Phase I Study Trial.

Metastatic castration-resistant prostate cancer (CRPC) remains incurable due to the lack of effective therapies. Activation of the human epidermal growth factor receptor 1 (HER1) in prostate cancer contributes to metastatic progression as well as to disease relapse. Here, we determined the toxicity and immunogenicity of a HER1-based cancer vaccine in CRPC patients included in a phase I clinical trial. CRPC patients (n = 24) were intramuscularly vaccinated with HER1 vaccine consisting of the extracellular domain of HER1 molecule (ECD) and very small size proteoliposome from Neisseria meningitidis (VSSP) and Montanide ISA-51 VG as adjuvants. Patients were included in five groups according to the vaccine dose (100, 200, 400, 600, and 800 µg). The primary endpoints were safety and immunogenicity. The anti-HER1 antibodies were measured by an ELISA, the recognition of an HER1 positive tumor cell line and the inhibition of HER1 phosphorylation by sera were determined by flow cytometry and western blot analysis, respectively. The HER1-specific T cell response was assessed by determination of IFN-γ-producing T cells using ELISpot assay. The vaccine was well tolerated. No grade III or IV adverse events were reported. High titers of anti-HER1 antibodies were observed in most of the evaluated patients. There were no significant differences regarding the geometric means of the anti-HER1 titers among the dose groups except the group of 100 µg in which antibody titers were significantly lower. A Th1-type IgG subclasses pattern was predominant in most patients. Only patients receiving the higher doses of vaccine showed significant tumor cell recognition and HER1 phosphorylation inhibition by hyperimmune sera. Forty two percent of the patients showed a specific T cell response against HER1 peptides pool in post-treatment samples. There was a trend toward survival benefit in those patients showing high anti-HER1 specific antibody titers and a significant association between cellular immune response and clinical outcome.

Evidence-based Guidelines for the Management of Exocrine Pancreatic Insufficiency After Pancreatic Surgery.

OBJECTIVE: To provide evidence-based recommendations for the management of exocrine pancreatic insufficiency (EPI) after pancreatic surgery. BACKGROUND: EPI is a common complication after pancreatic surgery but there is certain confusion about its frequency, optimal methods of diagnosis, and when and how to treat these patients. METHODS: Eighteen multidisciplinary reviewers performed a systematic review on 10 predefined questions following the GRADE methodology. Six external expert referees reviewed the retrieved information. Members from Spanish Association of Pancreatology were invited to suggest modifications and voted for the quantification of agreement. RESULTS: These guidelines analyze the definition of EPI after pancreatic surgery, (one question), its frequency after specific techniques and underlying disease (four questions), its clinical consequences (one question), diagnosis (one question), when and how to treat postsurgical EPI (two questions) and its impact on the quality of life (one question). Eleven statements answering those 10 questions were provided: one (9.1%) was rated as a strong recommendation according to GRADE, three (27.3%) as moderate and seven (63.6%) as weak. All statements had strong agreement. CONCLUSIONS: EPI is a frequent but under-recognized complication of pancreatic surgery. These guidelines provide evidence-based recommendations for the definition, diagnosis, and management of EPI after pancreatic surgery.

Effects of an epidermal growth factor receptor-based cancer vaccine on wound healing and inflammation processes in murine experimental models.

Anti-epidermal growth factor receptor (EGFR) therapies have been proven clinically effective for a variety of epithelial tumours. Vaccination of mice with the extracellular domain (ECD) of autologous EGFR overcomes the tolerance to self-EGFR and has antimetastatic effect on EGFR+ tumour. Because EGF/EGFR-signalling plays an important role in the inflammation stage of wound healing, the main objective of this study was to explore the possible role of murine (m) EGFR-ECD vaccine in the croton-oil-induced ear oedema and wound healing process in mice as autologous experimental models, mimicking the possible post-surgical wound complication in patients treated with human EGFR-ECD/VSSP vaccine. Mice were intramuscularly immunised four times; biweekly with the mEGFR-ECD/VSSP/Mont. Seven days later, an 8 mm diameter, full-thickness skin wound was created on the back of each animal. Immunisation induced a strong specific humoral response against the mEGFR-ECD protein and a DTH dose-response curve but interestingly, animals treated with mEGFR-ECD/VSSP/Mont had similar inflammatory and healing speed responses compared to control ones. These data suggest that application of mEGFR-ECD/VSSP vaccine as a therapeutic approach in cancer patients could not elicit a poor healing process after surgery.

Challenges and opportunities for cancer vaccines in the current NSCLC clinical scenario.

This review is aimed to focus on NSCLC as an emerging and promising model for active immunotherapy and the challenges for its inclusion in the current clinical scenario. Cancer vaccines for NSCLC have been focused as a therapeutic option based on the identification of a tumor hallmark and the active immunization with the related molecules that triggers cellular and/or humoral responses that consequently destroy or delay the rate of malignant progression. This therapeutic intervention in an established disease state has been aimed to impact into prolonging patient´s survival with ethically accepted quality of life. Understanding of relationship between structure and function in cancer vaccines is essential to interpret their opportunities to impact into prolonging survival and increasing quality of life in cancer patients. It is widely accepted that the failure of the cancer vaccines in the NSCLC scenario is related with its introduction in the advanced disease stages and poor performance status of the patients due to the combination of the tumor induced immunosuppression with the immune senescence. Despite first, second and emerging third line of onco-specific treatments the life expectancy for NSCLC patients diagnosed at advanced stages is surrounding the 12 months of median survival and in facts the today real circumstances are extremely demanding for the success inclusion of cancer vaccines as therapeutic choice in the clinical scenario. The kinetics of the active immunizations encompasses a sequential cascade of clinical endpoints: starting by the activation of the immune system, followed by the antitumor response and finalizing with the consequential impact on patients' overall survival. Today this cascade of clinical endpoints is the backbone for active immunization assessment and moreover the concept of cancer vaccines, applied in the NSCLC setting, is just evolving as a complex therapeutic strategy, in which the opportunities for cancer vaccines start from the selection of the target cancer hallmark, followed by the vaccine formulation and its platforms for immune potentiating, also cover the successful insertion in the standard of care, the chronic administration beyond progression disease, the personalization based on predictors of response and the potential combination with other targeted therapies.

Comparative in vitro and experimental in vivo studies of the anti-epidermal growth factor receptor antibody nimotuzumab and its aglycosylated form produced in transgenic tobacco plants.

A broad variety of foreign genes can be expressed in transgenic plants, which offer the opportunity for large-scale production of pharmaceutical proteins, such as therapeutic antibodies. Nimotuzumab is a humanized anti-epidermal growth factor receptor (EGFR) recombinant IgG1 antibody approved in different countries for the treatment of head and neck squamous cell carcinoma, paediatric and adult glioma, and nasopharyngeal and oesophageal cancers. Because the antitumour mechanism of nimotuzumab is mainly attributed to its ability to interrupt the signal transduction cascade triggered by EGF/EGFR interaction, we have hypothesized that an aglycosylated form of this antibody, produced by mutating the N(297) position in the IgG(1) Fc region gene, would have similar biochemical and biological properties as the mammalian-cell-produced glycosylated counterpart. In this paper, we report the production and characterization of an aglycosylated form of nimotuzumab in transgenic tobacco plants. The comparison of the plantibody and nimotuzumab in terms of recognition of human EGFR, effect on tyrosine phosphorylation and proliferation in cells in response to EGF, competition with radiolabelled EGF for EGFR, affinity measurements of Fab fragments, pharmacokinetic and biodistribution behaviours in rats and antitumour effects in nude mice bearing human A431 tumours showed that both antibody forms have very similar in vitro and in vivo properties. Our results support the idea that the production of aglycosylated forms of some therapeutic antibodies in transgenic plants is a feasible approach when facing scaling strategies for anticancer immunoglobulins.

Linking oncogenesis and immune system evasion in acquired resistance to EGFR-targeting antibodies: Lessons from a preclinical model.

Searching for biomarkers that associated with the acquired resistance of malignant cells to epidermal growth factor receptor (EGFR)-targeting monoclonal antibodies is crucial to improve the clinical benefits of these therapeutic agents. We have recently demonstrated that molecular alterations in both oncogenic and immunological pathways may be responsible for such an insensitivity. Our findings suggest that a combination of targeted anticancer agents and immunomodulatory drugs may be useful for overcoming the acquired resistance of cancer cells to EGFR-specific monoclonal antibodies.

Induction of immunogenic apoptosis by blockade of epidermal growth factor receptor activation with a specific antibody.

Despite promising results in the use of anti-epidermal growth factor receptor (EGFR) Abs for cancer therapy, several issues remain to be addressed. An increasing emphasis is being placed on immune effector mechanisms. It has become clear for other Abs directed to tumor targets that their effects involve the adaptive immunity, mainly by the contribution of Fc region-mediated mechanisms. Given the relevance of EGFR signaling for tumor biology, we wonder whether the oncogene inhibition could contribute to Ab-induced vaccine effect. In a mouse model in which 7A7 (an anti-murine EGFR Ab) and AG1478 (an EGFR-tyrosine kinase inhibitor) displayed potent antimetastatic activities, depletion experiments revealed that only in the case of the Ab, the effect was dependent on CD4(+) and CD8(+) T cells. Correspondingly, 7A7 administration elicited a remarkable tumor-specific CTL response in hosts. Importantly, experiments using 7A7 F(ab')(2) suggested that in vivo Ab-mediated EGFR blockade may play an important role in the linkage with adaptive immunity. Addressing the possible mechanism involved in this effect, we found quantitative and qualitative differences between 7A7 and AG1478-induced apoptosis. EGFR blocking by 7A7 not only prompted a higher proapoptotic effect on tumor metastases compared with AG1478, but also was able to induce apoptosis with immunogenic potential in an Fc-independent manner. As expected, 7A7 but not AG1478 stimulated exposure of danger signals on tumor cells. Subcutaneous injection of 7A7-treated tumor cells induced an antitumor immune response. This is the first report, to our knowledge, of a tumor-specific CTL response generated by Ab-mediated EGFR inhibition, suggesting an important contribution of immunogenic apoptosis to this effect.

Multicentre study of liver metastases from colorectal cancer in pathological livers.

OBJECTIVES: Resection of colorectal cancer (CRC) liver metastases (LM) in pathological liver (PL) patients (with cirrhosis or hepatopathy) is extremely rare. The aim of this study was to perform a multicentre, retrospective analysis of epidemiology, surgical techniques and outcomes in patients with PL who underwent hepatic resection for CRC-LM. METHODS: A retrospective, multicentre questionnaire was distributed to 15 hepatopancreatobiliary surgical units. RESULTS: Only six of 15 (40%) HPB units reported any experience in the surgical resection of CRC-LM in patients with PL. Of the 20 patients identified, 10 had underlying cirrhosis and 10 had chronic hepatopathy. Their median age was 66 years (range: 49-81 years). Thirteen patients were male. Liver dysfunction was known preoperatively in 18 patients. All patients had Child-Pugh class A disease. Six patients had synchronous disease. There were a total of 38 lesions among the 20 patients, distributed at a median of one lesion per patient (range: 1-4 lesions). The median size of the lesions was 3.0 cm (range: 1.5-9.0 cm). Preoperative median carcinoembryonic antigen (CEA) was 32.3 ng/ml (range: 1-184 ng/ml). The surgical procedures performed included: sub-segmentectomy (n= 12); left lateral sectionectomy (n= 6); segmentectomy (n= 4); radiofrequency ablation (n= 3), and exploratory laparotomy (n= 4). Morbidity occurred in four patients (Clavien grades I [n= 1], II [n= 2] and IVa [n= 1]). Mortality was nil. An R0 resection margin was achieved in 15 of 16 patients. Twelve patients did not receive chemotherapy. In resected patients, 10 presented with relapse. The median disease-free and overall survival periods were 12.2 and 22.3 months, respectively. CONCLUSIONS: When feasible, liver resection is the best option for CRC-LM in PL patients.

Purification process development for HER1 extracellular domain as a potential therapeutic vaccine.

HER1 is a tumor associated antigen emerging as an attractive target for cancer therapy. In the present study we demonstrated for first time that HER1 extracellular domain can be purified by a downstream process at pilot scale based on immunoaffinity chromatography from bioreactor supernatant of HEK 293 transfectomes. Filtered supernatant was applied to CNBr-activated Sepharose CL-4B with monoclonal antibody anti-human EGF immobilized, followed by three additional chromatographic polishing steps. HER1 extracellular domain was obtained with high purity (>95%), low DNA content, and biological activity.

T cells are crucial for the anti-metastatic effect of anti-epidermal growth factor receptor antibodies.

Experimental evidences supporting the epidermal growth factor receptor (EGFR) as an important molecule for tumor metastasis had been accumulated. Currently, anti-EGFR monoclonal antibodies (mAbs) constitute a promising approach for the treatment of patients with metastatic tumors. However, the mechanisms associated with the potent anti-metastatic effect of these mAbs have not been completely elucidated due to the lack of appropriate syngeneic preclinical models. In this paper, we have investigated the effects of 7A7, an antibody specific to murine EGFR, on the metastatic properties of D122 murine lung carcinoma. 7A7 mAb significantly impaired metastatic spread of D122 cells in C57BL/6 mice by direct anti-proliferative and pro-apoptotic effects on tumor metastasis. 7A7 mAb capacity to inhibit EGFR activation on D122 cells could contribute to its anti-metastatic effect. In addition, 7A7 mAb was able to induce in vitro antibody-dependent cell-mediated cytotoxicity on D122 cells. Interestingly, 7A7 mAb treatment increased the number of natural killer cells, T lymphocytes and dendritic cells infiltrating the metastatic sites. More strikingly, depletion of CD8(+) and CD4(+) T cells in vivo completely abrogated the 7A7 mAb anti-metastatic activity whereas function of natural killer cells was irrelevant. This study supports an in vivo role for T cell response in the mechanism of action of anti-EGFR mAbs, suggesting the induction of an adjuvant effect.

7A7 MAb: a new tool for the pre-clinical evaluation of EGFR-based therapies.

The epidermal growth factor receptor (EGFR) is highly expressed in many types of epithelial tumors. EGFR overexpression has been associated with an advanced stage of the disease, with resistance to standard therapies, and, for certain tumors, with poor patient prognosis. As a result, EGFR has been considered a meaningful target in anti-tumor strategies. Active and passive immunotherapies blocking EGFR and its ligands have been explored. But for successful pre-clinical evaluation of these approaches, well-established murine tumor models are not available and highly desirable. We described, for the first time, the generation and characterization of an anti-murine EGFR extracellular domain monoclonal antibody (7A7 MAb) (IgG1). 7A7 was generated by immunization of Balb/c mice with the recombinant extracellular domain of murine EGFR (rECD-mEGFR). 7A7 recognized an epitope present in the amino acidic core of the antigen and is cross-reactive with the human EGFR. Interestingly, this MAb was able to specifically bind EGFR at the cell surface, allowing the assessment of its differential expression in a panel of murine cells. Noteworthy, in a preliminary immunohistochemical study with 7A7 MAb, recognition of Balb/c mice skin sections and EGFR-positive tumors were observed. We concluded that 7A7 MAb is a valuable tool for EGFR-based therapeutic pre-clinical studies.