Effect of different liver resection methods on liver damage and regeneration factors VEGF and FGF-2 in mice.

BACKGROUND: Different approaches to study liver regeneration in murine models have been proposed. We investigated the effect of different liver resection models on liver damage and regeneration parameters in mice. METHODS: We compared the technical aspect of the 2 most commonly used techniques of 50% and 70% liver resection. Liver damage, as determined by the change in serum alanine aminotransferase and aspartate aminotransferase, as well as the regeneration parameters VEGF and FGF-2 were analyzed at 6 time points. A postoperative vitality score was introduced. RESULTS: Cholestasis was not observed for either technique. Both resection techniques resulted in full weight recovery of the liver after 240 hours, with no significant difference between sham and resection groups. Postoperative animal morbidity and total protein levels did not differ significantly for either method, indicating early and full functional recovery. However, comparing the mitogenic growth factors FGF-2 and VEGF, a significant increase in serum levels and, therefore, increased growth stimulus, was shown in the extended resection group. CONCLUSION: Extended resection led to a greater response in growth factor expression. This finding is important since it shows that growth factor response differs acdording to the extent of resection. We have demonstrated the need to standardize murine hepatic resection models to adequately compare the resulting liver damage.

[Association between vascular endothelial growth factor gene 936 T/C polymorphism and colorectal cancer together with anastomotic leakage].

OBJECTIVE: To investigate the association between VEGF gene 936 T/C polymorphism and colorectal cancer together with anastomotic leakage. METHODS: Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to detect the VEGF 936 T/C genotypes in colorectal cancer patients and healthy controls. RESULTS: There was no significant difference in the frequency of VEGF 936 C/C genotype or C allele between colorectal cancer patients and healthy controls (P > 0.05). The C/C genotype or C allele in colorectal cancer patients with anastomotic leakage was less frequently found than in the group without anastomotic leakage (P < 0.05). CONCLUSIONS: VEGF 936 C/C genotype or C allele is not related to the development of colorectal cancer, but they can reduce the risk of anastomotic leakage after surgery in colorectal cancer patients.

Enhanced green fluorescent protein-transfection of murine colon carcinoma cells: key for early tumor detection and quantification.

Many animal models for metastatic colorectal cancer represent clinical manifestations just inaccurately. We introduce a novel mouse model for metastastatic colorectal cancer. In order to remain close to the clinical disease a syngenic murine colon carcinoma cell line (colon 26 cells) was transfected with enhanced green fluorescent protein (EGFP). The transfected cells maintain the highly malignant attributes of the wild-type cells. Following injection into the portal circulation of Balb/c-mice, liver metastases occur in the same time span. Using the fluorescent attributes of the transfected cells, an approximation of the tumor load in liver tissue can be achieved by fluorescence activated cell sorting (FACS) and fluoroscan analysis. Tumor cell load in liver tissue can be accurately measured by Northern blot and Western blot analysis of liver tissue containing EGFP-transfected colon cancer metastases (1250 cells/mg liver tissue and 1000 cells/mg liver tissue) respectively. Confocal microscopy and intravital microscopy confirmed the growth of tumor metastases, originating from the intravascular compartments. The presented animal model using EGFP-transfected colon 26 cells allows the detecting of tumor growth in vivo and post mortem, as well as an accurate quantification of the tumor load in the liver tissue.

Prognostic implications of routine, immunohistochemical, and molecular staging in resectable pancreatic adenocarcinoma.

Cure for ductal adenocarcinoma of the pancreas is restricted to resectable tumors, but survival after surgery is still poor. Despite apparently curative resection, these cancers rapidly recur. Thus, the present pathologic examination should be enriched by sensitive methods to detect minimal residual disease. In a prospective setting we studied the frequency of minimal residual disease after curative resection by routine histopathology, immunohistology, and polymerase chain reaction (PCR) for mutated K-ras. Furthermore, the prognostic implication of detecting of MRD was determined. Prospectively, tumor tissue and corresponding paraaortic lymph nodes were obtained from 78 patients, who underwent surgery for pancreatic head tumors between 1999 and 2001. Sixty-nine of 78 cases were diagnosed for ductal adenocarcinoma (study group), whereas nine cases were diagnosed for benign pancreatic tumors (control group). Paraaortic lymph nodes were examined in step sections by routine histopathology (hematoxylin and eosin) and immunohistology using a pan-cytokeratin antibody. DNA of the primary tumor and corresponding paraaortic lymph nodes were analyzed by PCR-based assays with respect to mutated K-ras in codon 12. The recurrence-free survival and overall survival were correlated with the results of the latter methods. In 3 of 69 patients tumor cells were detected in paraaortic lymph nodes by routine histopathology and in 5 of 69 patients by immunohistology. K-ras mutations were detected in 42 of 69 ductal adenocarcinomas (61%), whereas 12 (17%) were positive in paraaortic lymph nodes. All of the latter patients had recurrence after surgery and a significant poorer survival than those without mutated K-ras. Furthermore, paraaortic lymph nodes diagnosed for K-ras mutation were independent prognostic markers in multivariate analysis. In the control group K-ras mutations were detected in one adenoma of Vater's papilla but not in paraaortic lymph nodes. Tumor cell DNA can be detected more sensitively by the described PCR method than with hematoxylin and eosin or immunohistologic staining, leading to a higher sensitivity for detection of micrometastases. The described PCR method clearly determines subgroups of patients after curative resection with early recurrence and poor survival and could therefore enrich the pathologic examination.

Tissue expression and sero-reactivity of tumor-specific antigens in colorectal cancer.

The expression of 14 individual and two groups of tumor antigens was characterized for colorectal carcinoma by RT-PCR using 26 colorectal carcinoma specimens, eight cell lines, six samples of patients with inflammatory bowl diseases, and nine specimens from different locations of an individual patient with a metastasized rectal carcinoma. The most frequently detected mRNAs were MAGE-A1 (58%), GAGE-3-7 (54%), and cTAGE-5a (31%). At medium frequencies (12-19%) we found cTAGE-1, MAGE-A2, se57-1, RAGE-4, and GAGE-1,2,8, while other tumor antigens were expressed rarely (<9%). 85% of the samples were positive for at least one of the most frequently expressed antigens. Using a secondary SEREX approach and sera of eight colorectal cancer patients we found reactive antibodies against recombinant cTAGE-1 (2 sera), se57-1 (2), truncated GAGE (1), and MAGE-A1 (1). We conclude that certain cancer-germline genes can be detected in colorectal cancer and might therefore be promising targets for immunotherapy.

Supplementation and inhibition of nitric oxide synthesis influences bacterial transit time during bacterial translocation in rats.

In the obstructed gut, nitric oxide (NO) may influence intestinal barrier function and translocation of bacteria. By using a novel experimental approach, we investigated the effect of supplementation and inhibition of NO synthesis on the time interval necessary for translocation of green fluorescent protein-transfected Escherichia coli (GFP-uv E. coli) in a rat model of small bowel obstruction. In anesthetized Wistar rats, 4 x 10(8) GFP-uv E. coli were administered into a reservoir of terminal ileum formed by ligature. Animals were randomized to receive either i.v. arginine (10 mg/kg), aminoguanidine (300 mg/kg), L-NAME (25 mg/kg), or saline (control). Translocation of GFP-uv E. coli was assessed using intravital video microscopy. Minimal transit time of translocation was measured as time from injection of GFP-uv E. coli into the gut lumen until bacteria were observed in the lamina submucosa and as time from injection of bacteria into the gut lumen until bacteria were observed in the lamina muscularis propria. Minimal transit times were expressed as mean +/- SD. Bacterial translocation into the submucosa and muscularis propria took 36 +/- 7 min and 81 +/- 9 min, respectively in control animals receiving saline. Aminoguanidine and L-NAME caused a marked delay of minimal transit time into the submucosa (63 +/- 5 min and 61 +/- 7 min, respectively; P < 0.05). Arginine significantly accelerated bacterial translocation into the muscularis propria (61 +/- 9 min, P < 0.05). GFP-uv E. coli were detected on frozen sections of small bowel, mesentery, liver, and spleen 2 h after GFP-uv E. coli administration in all animals. A marked upregulation of inducible NO synthase (NOS) in the obstructed bowel segment was demonstrated on immunohistochemistry. The assessment of a newly defined parameter, minimal bacterial transit time, may serve as an additional functional aspect of intestinal barrier function for pathophysiological and pharmacological studies. Aminoguanidine, L-NAME, and arginine were effective in influencing minimal transit time of E. coli during small bowel obstruction.

Gas gangrene pyaemia with myocardial abscess formation--fatal outcome from a rare infection nowadays.

We report a case of sudden death after gas gangrene. A 67-year-old male patient with diabetes mellitus and chronic renal failure (on haemodialysis three times a week) presented in the surgical emergency department with a severe swelling and crepitation in the right groin. No signs of trauma were present-except for a well-healed, 1-year-old scar after femoro-popliteal bypass surgery. Two days earlier, he had presented to the internal medicine department with epigastric pain and had left against medical advice. On readmission the patient was initially conscious and in a stable cardiopulmonary condition but developed sudden cardiocirculatory failure and underwent resuscitation. Despite all resuscitation measures, including the administration of high doses of catecholamines and the treatment of hyperkalemia, the patient died. Autopsy revealed septicaemia with rod-shaped gram-positive bacteria, typical of Clostridium perfringens, evidenced by multiple areas of myonecrosis. Abscess formation was found in the myocardium. Clostridial gas gangrene is a rare clinical condition. Unless immediate diagnosis and adequate therapy measures are taken, the outcome and chances for survival are poor as demonstrated by this case.

Microscopy of bacterial translocation during small bowel obstruction and ischemia in vivo--a new animal model.

BACKGROUND: Existing animal models provide only indirect information about the pathogenesis of infections caused by indigenous gastrointestinal microflora and the kinetics of bacterial translocation. The aim of this study was to develop a novel animal model to assess bacterial translocation and intestinal barrier function in vivo. METHODS: In anaesthetized male Wistar rats, 0.5 ml of a suspension of green fluorescent protein-transfected E. coli was administered by intraluminal injection in a model of small bowel obstruction. Animals were randomly subjected to non-ischemic or ischemic bowel obstruction. Ischemia was induced by selective clamping of the terminal mesenteric vessels feeding the obstructed bowel loop. Time intervals necessary for translocation of E. coli into the submucosal stroma and the muscularis propria was assessed using intravital microscopy. RESULTS: Bacterial translocation into the submucosa and muscularis propria took a mean of 36 +/- 8 min and 80 +/- 10 min, respectively, in small bowel obstruction. Intestinal ischemia significantly accelerated bacterial translocation into the submucosa (11 +/- 5 min, p < 0.0001) and muscularis (66 +/- 7 min; p = 0.004). Green fluorescent protein-transfected E. coli were visible in frozen sections of small bowel, mesentery, liver and spleen taken two hours after E. coli administration. CONCLUSIONS: Intravital microscopy of fluorescent bacteria is a novel approach to study bacterial translocation in vivo. We have applied this technique to define minimal bacterial transit time as a functional parameter of intestinal barrier function.

Association between EGF, TGF-{beta}1, TNF-{alpha} gene polymorphisms and cancer of the pancreatic head.

BACKGROUND: To date, EGF 61*A/G, TGF-ß1 -509*T/C and TNF-α -308*A/G gene polymorphisms have been not been analysed in pancreatic carcinoma. This study investigated the frequency of these gene polymorphisms among patients with cancer of the pancreatic head. PATIENTS AND METHODS: A total of 73 pancreatic head cancer patients and 117 cancer-free healthy people were recruited at the Surgical Department of the University Hospital Mannheim. Genomic DNA was isolated from peripheral blood and gene polymorphisms were analysed by PCR-RFLP. RESULTS: The distribution of EGF 61*G/G homozygotes among pancreatic head cancer patients was more frequent than that in the control group (24.7% vs 11.1%, odds ratio (OR) = 2.618, 95% confidence interval (CI) = 1.195-5.738). In addition, the frequency of the G allele in the pancreatic head cancer patient group was also higher than that in the control group (45.9% vs. 33.3%, OR = 1.696, 95% CI = 1.110-2.592). No difference was found for the TGF-ß1 -509 and TNF-α -308 genotypes among pancreatic head cancer patients and healthy controls. CONCLUSION: The frequencies of the EGF 61*G/G genotype and G allele are significantly increased among patients with pancreatic head cancer. TGF-ß1-509*T/C and TNF-α -308*A/G gene polymorphisms are not related to this cancer entity.

Association between EGF, TGF-beta1, VEGF gene polymorphism and colorectal cancer.

INTRODUCTION: Up to the present, EGF 61 A/G, TGF-beta1 -509 T/C, and VEGF 936 T/C gene polymorphisms have been analyzed in other cancer entities than colorectal cancer. We have now investigated the frequency of these gene polymorphisms among colorectal cancer patients. MATERIAL AND METHODS: A total of 157 colorectal cancer patients and 117 cancer-free healthy people were recruited at the Surgical Department of the Universitätsklinikum Mannheim. All patients and healthy people are Caucasians. Genomic DNA was isolated from peripheral blood, and gene polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). RESULTS: The distribution of EGF 61 G/G homozygotes among colorectal cancer patients was more frequent than that in the control group (33.1% versus 11.1%; Odds Ratio [OR]=3.962; 95% Confidence Interval [CI]=2.036-7.708). The frequency of the "G" allele in the colorectal cancer patient group was also higher than that in the control group (51.3% versus 33.3%; OR=2.105; 95% CI=1.482-2.988). No difference could be found for the TGF-beta1 and VEGF genotypes among colorectal cancer patients and healthy controls. CONCLUSIONS: The EGF 61 G/G genotype and the G allele are significantly related to colorectal cancer. The TGF-beta1 -509 T/C and VEGF 936 T/C gene polymorphisms are not related to colorectal cancer.

The role of laparoscopy in the treatment of complications after colonoscopy.

Perforations of the colonic wall or splenic injury during colonoscopy are rare complications. Treatment of these complications by laparoscopy is an advisable compromise instead of an invasive surgery with a laparotomy or a noninvasive and potentially risky nonoperative therapy. All surgical procedures that can be performed by open approach can also be performed laparoscopically. We present in this report 15 patients who were treated for a perforation after colonoscopy. In addition, 2 cases of splenic injury after colonoscopy are described. Twelve perforations were sutured laparoscopically and 3 perforations were sutured via laparotomy. Except for 1 minor wound infection, there were no complications. One splenic injury was treated by spleen wrapping via an open approach due to former pancreatic surgery, and 1 injury was treated laparoscopically with a hemostypticum. Mortality was 0%. Early laparoscopic intervention is a safe and effective method in the treatment of serious complications after colonoscopy.

[Association between tumor necrosis factor alpha gene polymorphism and colorectal cancer].

OBJECTIVE: To elucidate the association of TNF-alpha-308G/A gene functional polymorphism with the development and progression of colorectal cancer. METHODS: PCR-RFLP was employed to detect the TNF-alpha-308 G/A genotypes in 157 colorectal cancer patients and 117 healthy controls. RESULTS: The frequency of TNF-alpha-308 genotype and allele were not significantly different between colorectal cancer patients and healthy controls (genotype chi(2)=1.054, P=0.591, allele chi(2)=0.404, P=0.525). The frequency of A/A genotype and A allele in III+IV stage (62 patients in total) were higher than those in I+II stages (85 patients in total) (A allele: 22.6% vs 12.9%, A/A genotype: 8.1% vs 1.2%), and the differences were significant (genotype P=0.048, OR=7.368, 95% CI=0.839-64.743, allele chi(2)=4.720, P=0.03, OR=1.962, 95% CI=1.061-3.628). The frequency of TNF-alpha-308 genotype were not significantly different among different colorectal cancer grades (chi(2)=3.009,P=0.591). CONCLUSION: TNF-alpha-308G/A gene polymorphism is not associated with the development of colorectal cancer, but TNF-alpha-308 A/A genotype and A allele are related to the progression of colorectal cancer.

Imaging epidermal growth factor receptor phosphorylation in human colorectal cancer cells and human tissues.

In tumor cells, high phosphorylation levels of receptor tyrosine kinases may occur in the absence of exogenous ligands due to autocrine signaling or enhanced tyrosine kinase activity. Here we show that the phosphorylation state of the endogenous epidermal growth factor receptor (EGFR) can be quantitatively imaged in tumor cells and tissues by detecting fluorescence resonance energy transfer between fluorophores conjugated to antibodies against the receptor and phosphotyrosine, respectively. Five different human colorectal cell lines were analyzed for activity and expression of EGFR. All cell lines exhibited basal EGFR phosphorylation under serum starvation conditions. Phosphorylation levels increased after stimulation with EGF or pervanadate, dependent on the level of basal EGFR phosphorylation in the respective cell lines. This basal activity correlated inversely with receptor expression. Using the acceptor photobleaching fluorescence resonance energy transfer imaging approach, a significantly higher phosphorylation state of EGFR was also found in resected human colorectal tumor samples as compared with adjacent healthy tissue. Imaging of EGFR phosphorylation may thus serve as a valuable tool to investigate the role of receptor tyrosine kinase activity in malignant cell growth.

Resection for cancers of the pancreatic head in patients aged 70 years or over.

OBJECTIVE: To find out if resections of cancers of the head of pancreatic are justified in patients over the age of 70 years. DESIGN: Retrospective study. SETTING: University hospital, Germany. SUBJECTS: 519 patients with cancers of the pancreatic head, 93 (18%) of whom were aged 70 or over. MAIN OUTCOME MEASURES: Comparison of outcomes between those aged 70 or over, and those aged less than 70. RESULTS: There were 247 ductal adenocarcinomas, 134 carcinomas of the papilla of Vater, 79 carcinomas of the distal common bile duct, and 59 miscellaneous tumours. Of all variables compared (age, sex, symptoms, operations, clinical and pathological stage. morbidity, mortality, and long-term survival) the only significant difference between the groups was that leaks from the pancreaticojejunostomy occured more often in the older age group (p = 0.02). However, this did not influence overall morbidity or mortality. CONCLUSION: Patients' age is not a limiting factor in attempts at curative resection of cancers of the head of pancreas. If the tumour is resectable and patient is motivated and well enough, resection is indicated whatever the age.

Long-term results of partial pancreaticoduodenectomy for ductal adenocarcinoma of the pancreatic head: 25-year experience.

The prognosis of patients who undergo resection for pancreatic ductal adenocarcinoma with curative intention is generally poor unless they have early-stage disease. Based on our 25-year experience, the results of 194 patients after a standardized Kausch-Whipple resection for adenocarcinoma of the pancreatic head were analyzed and the prognostic factors were evaluated. Between 1972 and 1998 a total of 221 patients were diagnosed for ductal adenocarcinoma of the pancreatic head, and 194 of them subsequently underwent a standardized Kausch-Whipple resection. Long-term results and prognostic factors were examined by multivariate and univariate analyses. The overall postoperative mortality was 3.09%, and the morbidity was 29.9%. By multivariate analysis only curative resection (R0) was significantly related to a favorable prognosis ( p < 0.0001). Furthermore, in case of a curative resection, the presence of lymph node metastases showed prognostic significance in the multivariate analysis ( p = 0.005). Cumulative survival analysis revealed a 5-year survival rate of 25.4%, a 7-year survival rate of 12.3%, and a 10-year survival rate of 8.2% for patients who underwent curative resection (R0) for adenocarcinoma of the pancreatic head. We demonstrated that the R0 status is the only independent prognostic factor after surgery for adenocarcinoma of the pancreatic head. In the case of a curative resection, the presence of lymph node metastases is of prognostic relevance. In view of considerable surgical morbidity and mortality, resection for cancer of the pancreatic head is the only option if the lesion is resectable. We concluded that surgical treatment is "as good as it gets," as extended techniques have not proved to produce better results.

Prognostic impact of cysteine proteases cathepsin B and cathepsin L in pancreatic adenocarcinoma.

OBJECTIVES: The cysteine proteases cathepsin B (CTSB) and L (CTSL) have been implicated in tumor spread and metastatic formation. In pancreatic adenocarcinoma, the role of these proteases is not very well defined. To find out which cell types produce CTSB and CTSL and to evaluate the prognostic impact of these proteases, 70 specimens from curatively resected patients with pancreatic adenocarcinoma were examined by in situ hybridization and immunohisto-chemistry. METHODS: Seventy patients with ductal adenocarcinoma of the pancreas were studied after R0 resection with a follow-up of at least 3 years. CTSB and CTSL expression was performed immunohisto-chemically using polyclonal anti-CTSB and CTSL antibodies. To detect cell types involved in producing CTSB and CTSL as well as the intracellular localization of specific mRNA sequences, nonisotopic in situ hybridization was performed. The correlations among CTSB and CTSL expression, clinicopathologic parameters, and clinical outcome were analyzed. RESULTS: The immunoreactivity was 96% for CTSB and 90% for CTSL. Positive mRNA signals were obtained in the cytoplasm tumor cells, macrophages, and fibroblasts in 77% for CTSB and 81% for CTSL, respectively. Statistical analysis showed a significant correlation between CTSB/CTSL expression and tumor grading (P < 0.05) and between CTSB and lymphatic invasion (P = 0.05). Kaplan-Meier analyses revealed statistical significance for CTSB/CTSL expression with the survival after curative resection (P < 0.05). Both proteases are strong prognostic markers in multivariate analysis (P = 0.0001) beside UICC stage, nodal status, tumor size, and grading (P < 0.05). Furthermore, CTSB expression is an independent prognostic marker for cancer recurrence within 6 months after curative surgery in multivariate analysis (P = 0.0001). CONCLUSIONS: CTSB and CTSL are strong and independent prognostic markers in resectable pancreatic adenocarcinoma rather than UICC stage, TNM classification, or tumor grading. Furthermore, CTSB is a predictor for early recurrence after curative resection. These data underline the significance of tumor-associated proteolysis for cancer invasion and metastasis and may lead to defining subgroups of patients with early recurrence and poor outcome.

The gut origin of bacterial pancreatic infection during acute experimental pancreatitis in rats.

BACKGROUND: Infections are frequent complications and determine clinical course and outcome in severe pancreatitis. A novel animal model was used to assess minimal transit time of bacterial translocation (BT) across the gut mucosa in vivo using green fluorescent protein-transfected Escherichia coli and intravital video microscopy. METHODS: Three hours after induction of acute pancreatitis by i.p. injection of 40 microg/kg cerulein, 0.5 ml of a suspension of green fluorescent protein-transfected E. coli were injected into the lumen of a small bowel reservoir formed by ligature in anesthetized Wistar rats. Translocation of E. coli was assessed by intravital microscopy. Animals were sacrificed 5 h after induction of pancreatitis. RESULTS: BT across the mucosa and into the muscularis propria took a mean +/- SD of 36.4 +/- 8 min and 80.9 +/- 9.5 min, respectively, in sham animals. Pancreatitis resulted in a significantly shorter minimal transit time across the mucosa (16.4 +/- 4.9 min, p = 0.007) and into the muscularis propria (47.7 +/- 2.5 min, p = 0.001). E. coli were detected on frozen cross-sections and on bacteriological examination of pancreatic tissue in animals with acute pancreatitis but not in controls. DISCUSSION: Intravital microscopy of fluorescent bacteria is a new approach towards studying BT in vivo. Minimal transit time of BT serves as a novel functional aspect of mucosal barrier function during acute pancreatitis. The observation of fluorescent bacteria translocating from the small bowel lumen into the pancreas provides substantial experimental proof for the gut-origin-hypothesis of infectious complications in pancreatitis.

Benefit of venous resection for ductal adenocarcinoma of the pancreatic head.

OBJECTIVE: To find out whether there is any benefit from venous resection during pancreaticoduodenectomy for ductal pancreatic adenocarcinoma. DESIGN: Retrospective study. SETTING: University Hospital Mannheim/Heidelberg, Germany. INTERVENTIONS: 271 patients had resections for ductal adenocarcinoma of the pancreatic head between 1980 and 2001. The outcome of patients who did (n = 68) and who did not (n = 203) have simultaneous resection of major veins (portal vein and/or superior mesenteric vein) were compared. MAIN OUTCOME MEASUREMENT: 5 year survival. RESULTS: The groups differed significantly regarding stage, perineural infiltration, lymphangiosis carcinomatosa, operating time, blood loss, and blood transfusion. However, there was no difference in perioperative morbidity (27% and 22%), mortality (4% and 3%), and long-term survival (at 5 years 23% and 24%). Subgroup analysis of patients with margins free of tumour (R0 resections) showed that those patients who had venous resections in whom histological examination did not show infiltration of tumour had the most favourable outcome. CONCLUSION: There is no reason to exclude patients with suspected venous infiltration from radical pancreaticoduodenectomy including venous resection.

Liver regeneration in FGF-2-deficient mice: VEGF acts as potential functional substitute for FGF-2.

BACKGROUND/AIMS: The angiogenic properties, its role in mesoderm differentiation and cell culture studies implicate an important role of fibroblast growth factor (FGF-2) in liver regeneration. The aim of the study was to evaluate this role in a FGF-2 knockout mouse model. METHODS: Liver regeneration after left hemihepatectomy (partial hepatectomy, PH) was evaluated in homozygous FGF-2 deficient (-/-) mice (male C57BL/6J) and their FGF-2 competent (+/+) littermates (controls) (day 0-10). RESULTS: FGF-2-(-/-) mice displayed normal dynamics in liver regeneration. FGF-2 protein was overexpressed 4 days post PH in controls. BrdU incorporation showed a biphasic pattern in FGF-2-(-/-) mice, whereas it decreased continuously after one peak (day 2) in controls. In FGF-2-(-/-) livers hepatic growth factor mRNA post PH was 1 day longer decreased and markedly less elevated thereafter compared with control. Vascular endothelial growth factor (VEGF) mRNA levels were clearly increased in FGF-2-(-/-) mice pre- and postoperatively in contrast to controls. VEGF protein levels in livers of FGF-2-(-/-) mice were elevated preoperatively, but similar in both groups after PH. With SU5416, a VEGF-receptor inhibitor, liver regeneration in FGF-2-(-/-) mice was reduced significantly, whereas it remained unchanged in controls. CONCLUSIONS: Liver regeneration dynamics in FGF-2-(-/-) mice were comparable with controls, potentially due to a functional substitution of FGF-2 by VEGF.