Clinical Significance of Disseminated Pluripotent Tumor Cell Signature Expression in the Bone Marrow from Patients with Colorectal Cancer

Purpose:

Disseminated tumor cells (DTCs) are critically involved in tumor relapse and survival in several invasive tumors. We previously showed that the ATP-binding cassette (ABC) transporter, ABCB5, is a chemoresistance mediator expressed on specific cell subsets in colorectal cancer (CRC) and other malignancies. This study evaluated the molecular signature expression and its clinical relevance of DTCs in bone marrow from patients with colon cancer.

Methods:

This study included 49 consecutive patients (UICC stage I-IV) that underwent curatively intended or palliative surgery for CRC. We analyzed cells from bone marrow aspirates obtained before surgery and derived from patients that had completed minimally a 5-year follow-up. The gene expression of ABCB5 in comparison to CD133 (molecule for identifying cancer initiating cells), Lgr5 (an intestinal stem cell marker) as well as Cytokeratin (CK) 20 (terminally differentiated tumor cells of epithelial origin) in these cells was evaluated.

Results:

Bone marrow analysis showed differential expression between the analyzed genes. ABCB5 and Lgr5 and to lesser extent CD133 and CK20 genes were significantly expressed in the analyzed cells from bone marrow aspirates while only ABCB5 and Lgr5 were significantly negative associated with tumor progress and overall survival.

Conclusion:

Overexpression of ABCB5 and Lgr5 in bone marrow negatively influenced patient survival pointing to a specific chemo resistant and pluripotent cell subgroup of DTCs in the bone marrow. ABCB5 like Lgr5 positive cells seem to be involved in limited tumor related patient survival, suggesting that ABCB5- and Lgr5-positive cells may be relevant for specific clinical intervention strategies

Ten-year follow-up of a prospective trial for the targeted therapy of gastric cancer with the human monoclonal antibody PAT-SC1

The fully human monoclonal antibody PAT-SC1 is specific for an isoform of CD55 (decay-accelerating factor) designated CD55^PAT-SC1. This antigen is expressed in the majority (80%) of gastric cancers (GCs), and the antibody induces tumour cell-specific apoptosis in vitro as well as in vivo. PAT-SC1, therefore, has been deemed promising as a therapeutic agent. Here, we describe the results of an academic clinical study performed in a neoadjuvant setting with resectable GC patients. Patients undergoing treatment for GC between 1997 and 2001 were tested for CD55^PAT-SC1 expression. Fifty-one resectable patients that tested positively received a single administration of 20 mg PAT-SC1 48 h prior to surgery. They underwent standard surgery with either subtotal or total gastrectomy with bursectomy, omentectomy and a modified D2-lymphadenectomy, aimed at R0 resection. Primary endpoints of the present study were to evaluate side-effects of the PAT-SC1 antibody treatment and to evaluate histopathological effects such as tumour regression and induction of apoptosis. Long-term survival was a secondary endpoint. Administration of PAT-SC1 appeared safe with only reversible side-effects according to WHO grade I and II. Despite the low-dose of the antibody, 81.6% of the patients showed signs of increased apoptosis within the primary tumour and 60% showed signs of tumour cell regression. Comparison of the 10-year survival rates of the R0-resected CD55^PAT-SC1-positive patients treated with the PAT-SC1 antibody with a historical collective of R0-resected CD55^PAT-SC1-positive patients not treated with PAT-SC1 indicated a survival benefit in the treated patients. Furthermore, comparison of the patient survival of CD55^PAT-SC1-positive vs. CD55^PAT-SC1-negative groups suggested that CD55^PAT-SC1 antigen expression is an independent predictor of poor survival in a Cox regression analysis. Antibody PAT-SC1 may be a useful additive therapeutic agent in the treatment of patients with CD55^PAT-SC1-expressing GCs. In combination with radical standard surgery, PAT-SC1 given as an adjuvant or neoadjuvant immunotherapeutic agent induces apoptosis in tumour cells which may improve survival of these patients. Because of the human origin and its specific binding to the CD55^PAT-SC1 antigen, PAT-SC1 was well tolerated in this trial.

[Blunt trauma with bullet-proof vests. Skin lesions are no reliable predictor of injury severity]

It is well known that so-called bullet-proof vests offer protection against a wide range of penetrating trauma, but their protection against blunt trauma is less well understood. Fast projectiles may result in hematomas and contusions behind the armour. We report a traffic accident involving a young soldier wearing a ballistic protection vest resulting in a right thoracoabdominal blunt trauma leading to a confined liver compression rupture. As nearly no skin marks were detectable, we point out that every emergency department surgeon should be very suspicious if a patient wore a ballistic vest at the time of the accident--there may be no skin marks despite severe intra-abdominal trauma. Our patient recovered following hypotensive ICU treatment, thrombocyte mobilization, and factor VIIa substitution.

Prognostic impact of allelic losses in 1p32–36 (HYTM1), 4p15.2 (D4S2397), 5q22.2 (D5S346), 8p22 (D8S254), 18q12.3 (D18S474), and microsatellite instability for colorectal cancer

4132

Background: The aim of this prospective study was to analyse the prognostic impact of allelic losses in the chromosomal regions 1p32–36 (HYTM1), 4p14–16 (D4S2397), 5q22 (D5S346), 8p21–22 (D8S254), 18q12.3 (D18S474) and microsatellite instability (MSI) in colorectal cancer (CRC). The microsatellite markers HYTM1, D4S2397, D8S254, and D18S474 were previously shown to have prognostic relevance in retrospective studies. The National Cancer Institute (NCI) microsatellite panel (BAT25, BAT26, D2S123, D5S346 and D17S250) was used for MSI-Analysis. Methods: Between July 1999 and February 2004, the data from a total of 165 patients, preoperatively diagnosed with colorectal cancer, and operated on in the Department of Surgery, University of Wuerzburg were collected. Inclusion criteria were: (a) electively operated primary adenocarcinomas; (b) obtainment of fresh paired normal mucosa-tumor samples; (c) no postoperative death (survival < 1 month); and (d) availability of follow-up data. Allelic loss (LOH) was determined by comparing the PCR-patterns of tumor DNA with corresponding normal tissue (signal reduction of at least 50%). MSI-L (low microsatellite instability) was defined as one marker out of five NCI-markers, MSI-H (high microsatellite instability) as more than two markers to display microsatellite instability. MSI-H tumours were excluded for further LOH-analysis. The endpoint of the study was tumour specific death. Kaplan-Meier survival curves were compared using the log-rank test. Results: We found expected frequencies in age, gender, tumour stage, and tumour grading. Tumour stage, grading, and an allelic loss of D18S474 was confirmed to be of prognostic significance for UICC I-IV, I-III, and II cancer in univariate analysis. Tumour stage and LOH D18S474 were also independent prognostic variables in stage I-IV and I-III. There was no significant prognostic impact of a loss of the markers HYTM1, D4S2397, D5S346, D8S254, MSI-L and MSI-H in either UICC stage I-IV, I-III, and II colorectal cancer patients. Conclusions: A loss of D18S474 defines a high-risk subgroup of patients with stage I-IV, I-III and stage II colorectal cancers.

No significant financial relationships to disclose.

Tumor cell dissemination in a human colon cancer animal model: orthotopic implantation or intraportal injection?

BACKGROUND

The development of therapeutic strategies for treatment of metastasized colorectal carcinoma requires biologically relevant and adequate animal models generating both metastases and the dissemination of tumor cells.

METHODS

To prove the efficiency of orthotopic implantation concerning induction of minimal residual disease (MRD) colorectal cancer tissue from 10 patients was transplanted orthotopically into nude mice. In the intraportal injection model 1 x 10(6) HT-29 human colon cancer cells were injected. We investigated by histological studies and CK-20 RT-PCR the occurrence of hematogenous metastases and the dissemination of human colon cancer cells in bone marrow.

RESULTS

Following orthotopic implantation of human colon cancer tissue the lymph node and hepatic metastasis rates were low. MRD as reflected by CK-20 positivity of the bone marrow was present in 22.2%. The intraportal injection of 1 x 10(6) HT-29 human colon cancer cells produced hepatic metastases in up to 89% of all animals. The intraportal injection of 1 x 10(6) cells also generated MRD in the bone marrow in 63% of animals.

CONCLUSIONS

The intraportal injection model represents a biologically relevant and adequate animal model for the induction of both reproducible hepatic metastasis and MRD in the bone marrow. In this regard it seems to be superior to the orthotopic implantation model.

The intraportal injection model: a practical animal model for hepatic metastases and tumor cell dissemination in human colon cancer

Background

The development of new therapeutic strategies for treatment of metastasized colorectal carcinoma requires biologically relevant and adequate animal models that generate both reproducible metastasis and the dissemination of tumor cells in the form of so-called minimal residual disease (MRD), an expression of the systemic character of neoplastic disease.

Methods

We injected immunoincompetent nude mice intraportally with different numbers (1 × 10⁵, 1 × 10⁶ and 5 × 10⁶ cells) of the human colon carcinoma cell lines HT-29 and SW-620 and investigated by histological studies and CK-20 RT-PCR the occurrence of hematogenous metastases and the dissemination of human tumor cells in bone marrow.

Results

Only the injection of 1 × 10⁶ cells of each colon carcinoma cell line produced acceptable perioperative mortality with reproducible induction of hepatic metastases in up to 89% of all animals. The injection of 1 × 10⁶ cells also generated tumor cell dissemination in the bone marrow in up to 63% of animals with hepatic metastases.

Conclusion

The present intraportal injection model in immunoincompetent nude mice represents a biologically relevant and adequate animal model for the induction of both reproducible hepatic metastasis and tumor cell dissemination in the bone marrow as a sign of MRD.

Growth of human gastric cancer cells in nude mice is delayed by a ketogenic diet supplemented with omega-3 fatty acids and medium-chain triglycerides

BACKGROUND

Among the most prominent metabolic alterations in cancer cells are the increase in glucose consumption and the conversion of glucose to lactic acid via the reduction of pyruvate even in the presence of oxygen. This phenomenon, known as aerobic glycolysis or the Warburg effect, may provide a rationale for therapeutic strategies that inhibit tumour growth by administration of a ketogenic diet with average protein but low in carbohydrates and high in fat enriched with omega-3 fatty acids and medium-chain triglycerides (MCT).

METHODS

Twenty-four female NMRI nude mice were injected subcutaneously with tumour cells of the gastric adenocarcinoma cell line 23132/87. The animals were then randomly split into two feeding groups and fed either a ketogenic diet (KD group; n = 12) or a standard diet (SD group; n = 12) ad libitum. Experiments were ended upon attainment of the target tumor volume of 600 mm3 to 700 mm3. The two diets were compared based on tumour growth and survival time (interval between tumour cell injection and attainment of target tumour volume).

RESULTS

The ketogenic diet was well accepted by the KD mice. The tumour growth in the KD group was significantly delayed compared to that in the SD group. Tumours in the KD group reached the target tumour volume at 34.2 +/- 8.5 days versus only 23.3 +/- 3.9 days in the SD group. After day 20, tumours in the KD group grew faster although the differences in mean tumour growth continued significantly. Importantly, they revealed significantly larger necrotic areas than tumours of the SD group and the areas with vital tumour cells appear to have had fewer vessels than tumours of the SD group. Viable tumour cells in the border zone surrounding the necrotic areas of tumours of both groups exhibited a glycolytic phenotype with expression of glucose transporter-1 and transketolase-like 1 enzyme.

CONCLUSION

Application of an unrestricted ketogenic diet enriched with omega-3 fatty acids and MCT delayed tumour growth in a mouse xenograft model. Further studies are needed to address the impact of this diet on other tumour-relevant functions such as invasive growth and metastasis.

[Antibody treatment in colorectal cancer--what the surgeon needs to know]

Advances in the medical treatment of colorectal cancer patients have resulted in considerable improvements through the introduction of new cytotoxic drugs. The significant progress in molecular and tumour biology has produced a great number of targeted, tumour-specific, monoclonal antibodies that are now in various stages of clinical development. Two of these antibodies, cetuximab (Erbitux) und bevacizumab (Avastin), directed against the epidermal growth factor receptor (EGFR) and the vascular epithelial growth factor (VEGF), respectively, have recently been approved for use in metastatic colorectal cancer. The combination of well-known and newly developed cytotoxic agents with monoclonal antibodies makes the medical treatment of colorectal cancer patients considerably more complex, but also provides additional therapeutic strategies for patients in advanced stages of disease.

Neoadjuvant therapy of gastric cancer with the human monoclonal IgM antibody SC-1: impact on the immune system

Adjuvant therapies for minimal residual disease are a promising approach to improve the poor survival rates after surgery of gastric tumors. A pilot study of a neoadjuvant therapy was performed using a human monoclonal IgM antibody (SC-1) specifically inducing apoptosis in signet ring cell stomach carcinomas. However, scarce information exists on how such a treatment affects the immune system, in particular what are the effects of apoptosis induction and infusion of large amounts of IgM. Thus, the leukocyte composition (CD3, CD4, CD8, CD19, CD16+56, CD14) and several cytokines (TNF-alpha, IL6, IL12, IFN-gamma, GM-CSF, Neopterin) before and after SC-1 application were measured and compared to results of patients that underwent surgical removal of gastric carcinoma without antibody treatment. After SC-1 application, an increase in TNF-alpha and a decrease of lymphocytes and CD3+ T-cells but in the range obtained in healthy individuals was observed before surgery. After surgery, the IL6 levels increased and the TNF-alpha levels remained at the elevated level. Furthermore, there was a significant drop in lymphocytes and CD3+ T-cells. These effects were due to the surgical treatment. Other parameters did not show significant changes. It seems that the application of an apoptosis-inducing antibody prior to surgery of gastric tumors has mild if any effect on the immune system. Therefore, from an immunological point of view, the treatment with this monoclonal antibody is extremely safe.

[Phlegmonous gastritis in a 44-year-old woman on immunosuppressive therapy]

HISTORY AND ADMISSION FINDINGS

A 44-year-old woman was on long-term immunosuppressive therapy with leflunomide and adalimumab for rheumatoid arthritis. She was admitted to the emergency room with diffuse abdominal pain of sudden onset. On physical examination she had rebound tenderness in all four abdominal quadrants.

INVESTIGATIONS

The white blood cell count was 3300/l, C-reactive protein 25 mg/dl and serum lactate 10 mmol/l. Abdominal computed tomography revealed a diffusely thickened gastric wall and ascites. At explorative laparotomy 1000 ml of a cloudy peritoneal fluid were aspirated and found to be negative for bacteria. But a culture of a mesenterial smear grew streptococci group A. Intra-operative endoscopy showed extensive hemorrhagic gastritis. Because there was no perforation or transmural necrosis gastric resection was not performed.

DIAGNOSIS, TREATMENT AND COURSE

Diffuse thickening of the gastric wall, extended mucosal necrosis and the peritoneal finding of streptococci in an immunocompromised patient suggested the diagnosis of phlegmonous gastritis. On treatment with antibiotics and proton pump inhibitor the patient made a slow recovery over the following eight weeks. Nine months after the event an asymptomatic antral stricture was noticed at follow-up gastroscopy.

CONCLUSION

Phlegmonous gastritis is a rare but life-threatening complication in immunosuppressed patients.

Feasibility and limits of an orthotopic human colon cancer model in nude mice

We sought to develop an accurate colorectal cancer model in nude mice with stable local growth, tumor cell dissemination, and reproducible metastatic capacity. To this end, we orthotopically transplanted histologically intact human colorectal cancer tissue from 10 human patients into nude mice. After successful local tumor growth, tumor tissues were retransplanted as many as 9 times in serial passage. All specimens were transplanted using microsurgical techniques. Histologic, immunohistochemical, and polymerase chain reaction techniques were used to determine tumor growth rates and kinetics, development of regional lymph node and distant hepatic metastases, and the induction of minimal residual disease (MRD). Stable local tumor growth rates with variable growth kinetics were detected in 73.4% of all mice. The lymph node and hepatic metastasis rates were low, at 18.4% and 4.9%, respectively. MRD, as reflected by CK20 positivity of the bone marrow in animals with lymph node and hepatic metastases, was present in 22.2%. The orthotopic colorectal cancer model described here is feasible for the induction of reproducible local tumor growth but is limited by variable growth kinetics and the low rate of lymph node and hepatic metastases. Cytokeratin-positive cells indicative of MRD could be detected in the bone marrow of approximately 25% of the nude mice with metastases. The observed induction of MRD after orthotopic implantation of intact human colon cancer in animals with lymph node and hepatic metastases might be improved if established colon cancer cell lines were used.

Giant fold gastritis with consecutive gastric carcinoma in a patient with peutz-jeghers syndrome

We describe the case of a 36-year-old patient with Peutz-Jeghers syndrome and a very unusual gastric morphology resembling giant fold gastritis. The latter lacked additional features of Menetrier's syndrome, was not influenced by eradication of Helicobacter pylori and persisted for more than ten years under regular endoscopic surveillance. Histologically, foveolar hyperplasia was found in the enlarged folds. Endoscopic ultrasound documented a hyperechoic widening of the gastric mucosa without involvement of the deeper layers. However, despite annual control gastroscopies, an adenocarcinoma developed between the folds and was in an already advanced stage at diagnosis (UICC III). We suggest that a variant of Peutz-Jeghers syndrome may be characterised by marked foveolar hyperplasia similar to Menetrier disease, and that not conventional endoscopy alone, but rather endoscopic ultrasound may be considered in such patients.

[New concepts in treatment of gastric carcinoma]

Despite interdisciplinary approach to gastric cancer the outcome of patients remains poor. Even after curative resection most patients suffer from progression of disease and metastasizing course. Adjuvant treatment like chemotherapy or radiation can not improve survival substantialy. This is discussed to be due to dissemination of tumor cells, which are not affected by most treatment options. The new concept of tumor specific antibody therapy with a monoclonal antibody is discussed as an effective treatment especially to fight disseminated tumor cells and thus might help to improve the outcome in stomach cancer.

Disseminated tumor cells in the blood of patients with gastric cancer are an independent predictive marker of poor prognosis

OBJECTIVE

Gastric cancer carries a poor prognosis even after curative resection (R0). Tumor progression in gastric cancer patients has been attributed to the persistence of disseminated tumor cells (DTC) in various body compartments as a sign of minimal residual disease, although the prognostic relevance of DTC is still unclear. In this study the prognostic relevance of DTC in the blood of gastric cancer patients was investigated.

MATERIALS AND METHODS

Venous blood samples of 70 cancer patients were taken intraoperatively before surgical manipulation and examined by reverse transcription-polymerase chain reaction (RT-PCR) for expression of cytokeratin 20 (CK20) as a marker for DTC. Tumor-related survival was analyzed using univariate and multivariate models assessing occurrence of DTC, residual tumor classification, and tumor stage. Median follow-up was 20 months (range 1-57 months).

RESULTS

Twenty-eight of the 70 patients (40%) were CK20 positive. The prevalence of DTC in patients following R0 resection (15/41, 37%) was similar to that in patients with residual tumor (13/29, 45%, NS). Furthermore, expression of CK20 was independent of TNM stage. Univariate analysis of R0-resected patients revealed CK20 to be a marker for significantly shorter tumor-related survival (p = 0.0363). In a multivariate analysis, CK20 was an independent prognostic marker. Detection of CK20 had greatest impact for early tumor stages (T1 and T2, N0; p < 0.0032).

CONCLUSIONS

Detection of DTC in venous blood of gastric cancer patients is an independent predictive marker of poor prognosis and thus could help to define patients for adjuvant therapy with this tumor entity.

Human antibody SC-1 reduces disseminated tumor cells in nude mice with human gastric cancer

Advanced gastric cancer is a systemic disease that requires adjuvant therapy targeted at eliminating disseminated tumor cells (DTCs). We investigated whether the apoptosis-inducing human monoclonal IgM antibody SC-1 was able to reduce the number of disseminated gastric cancer cells in blood and bone marrow. Human gastric tumor specimens with positive expression of the SC-1 receptor were transplanted in nude mice with metastasizing gastric cancer. After tumor growth (4-6 weeks) animals were randomly allocated to intraperitoneal 100 microg SC-1 (n=23) or 100 microg human IgM (n=23). One week later, animals were sacrificed and blood and bone marrow specimens were obtained. A nested RT-PCR for cytokeratin 20 (CK-20) from blood and bone marrow of mice was performed for detection of disseminated tumor cells. Animals receiving SC-1 had significantly fewer DTCs than did control animals (p=0.0011). None of the SC-1 mice had DTCs simultaneously in both blood and bone marrow versus four of the control animals (p=0.0363). The reduction of DTCs in SC-1 animals was due to reduction in bone marrow (p=0.032 compared to controls), but not in blood (p=0.1158). Treatment with SC-1 significantly reduced the number of DTCs in bone marrow in this animal model.

Expression profiling and genetic alterations of the selenoproteins GI-GPx and SePP in colorectal carcinogenesis

The trace element selenium is discussed as a chemopreventive agent in colorectal carcinogenesis. Selenocysteine-containing proteins, so-called selenoproteins, represent potential molecular targets for nutritive selenium supplementation. Due to their antioxidative potential, the selenoproteins gastrointestinal glutathione peroxidase (GI-GPx) and selenoprotein P (SePP) are considered to provide protection against reactive oxygen species (ROS), thereby reducing DNA damage and preventing development of colon cancer. GI-GPx and SePP are abundantly expressed in normal colon mucosa. Recently, we demonstrated both reduced SePP expression and increased GI-GPx expression in colorectal adenomas. In this study, we investigated the expression of SePP and GI-GPx in colorectal cancers compared with corresponding normal mucosa. Further, the occurrence of genetic alterations within the SePP and GI-GPx genes was analyzed. We observed a significant reduction or loss of SePP mRNA expression in colon cancers, whereas GI-GPx mRNA and protein expression varied between different tumor samples. In addition, we identified novel polymorphisms within the SePP and GI-GPx genes with so far unknown relevance for protein function. Our results argue against a general decrease of selenoprotein expression in colorectal carcinogenesis but imply specific differential regulation of expression of individual selenoproteins.

Tumor induction by activated JNK occurs through deregulation of cellular growth

Activation of the cytoplasmic (Ras-Raf-MEK-ERK) signaling cascade was shown to be both, necessary and sufficient for transformation in vitro as well as in vivo. However, over the last years the involvement of stress-activated protein kinases (SAPKs)/Jun N-terminal kinases (JNKs), and their substrate c-Jun in the process of cellular transformation has been suggested. To dissect the mechanisms through which JNK signaling contributes to the transformation process we employed a recently generated constitutively active version of this kinase, SAPKbeta-MKK7, which behaves like a weakly transforming oncogene in vitro. Dissection of the transforming potential of oncogenic JNK demonstrates that it is sufficient for tumor induction in nude mice. In vitro studies and analysis of tumor material support the conclusion that oncogenic JNK primarily transforms through its effects on cell proliferation and tumor vascularization but does not affect cell survival.

Optimization of a metastasizing human gastric cancer model in nude mice

Our purpose was to optimize the surgical orthotopic implantation (SOI) technique to create a reproducible gastric cancer model in nude mice with stable tumor growth and metastasizing course. We performed xenotransplantation of primary human tumor specimens from patients with gastric cancer (series 1) and orthotopic transplantation of tumor specimens originating from the gastric cancer cell line 23132/87 (series 2). All specimens were transplanted using microsurgical techniques. The two series were compared with regard to tumor growth rates and kinetics, development of metastases, and induction of minimal residual disease (MRD), as determined by histology and PCR techniques. In series 1 mice, the tumor growth rate was slow; in series 2 mice, it was both fast and reproducible. Unlike animals in series 1, animals in series 2 developed metastases and MRD. In conclusion, the optimized SOI technique presented here represents a reproducible and reliably metastasizing gastric cancer model.

Detection of disseminated tumor cells in nude mice with human gastric cancer

Disseminated tumor cells (DTC) are a potential contributor to relapse of cancer. In the present study we developed a model for induction of disseminated tumor cells in nude mice, which can aid in the search for therapeutic approaches as well as improve our understanding of metastasizing gastric cancer. To detect DTC in blood and bone marrow we established a modified animal model of orthotopic transplantation. Two groups of nude mice were used for xenotransplantation of gastric cancer specimens. In group I tumor specimens originating from a gastric adenocarcinoma cell line were transplanted onto the stomach; in group II they were transplanted subcutaneously into both axillaries. Tumor growth, metastases and presence of DTC were compared in both groups. For detection of DTC a nested reverse transcriptase polymerase chain reaction (RT-PCR) for human cytokeratin (CK)-20 was performed on blood and bone marrow of all mice. Tumor growth occurred in both groups (9/10 animals in group I, 10/10 in group II) within 14 weeks. Only animals in group I developed local invasive tumor growth, stenosis of the stomach and distant metastases. Tumors in animals of group II grew with local displacement only and developed no metastases. There were no signals of CK-20 detected in the blood in both groups. In group I, 5 of 9 animals had positive signals of human CK-20 in their bone marrow as a sign of DTC. In group II no DTC were detected in bone marrow. We conclude that orthotopic transplantation is a prerequisite for the development of DTC and metastasizing tumor growth in this modified gastric cancer model.

Short-term immunosuppression after rat parathyroid allotransplantation

The aim of this study was to evaluate whether short-term postoperative immunosuppression is able to sufficiently prolong graft survival after experimental allogeneic parathyroid transplantation. Heterotopic parathyroid transplantation was performed in 6 groups: 1) syngeneic control Lewis (LEW) to LEW; 2) allogeneic control Wistar-Furth (WF) to LEW; 3-5) WF to LEW plus short-term immunosuppression, postoperative days 1-13 (cyclosporine 5/10/20 mg/kg); and 6) WF to LEW plus 10 mg/kg CyA from preoperative day 7 to postoperative day 7. Graft function was examined up to 60 days; histological and immunohistological examination was performed on all grafts with impaired function. Graft function after syngeneic transplantation was indefinite, while recipients of allogeneic grafts turned hypocalcemic after 13 +/- 2 days. With immunosuppression, graft function was 21 +/- 2 days (groups 5 and 6) and 28 +/- 3 days (groups 3 and 4). Histologically, a cellular infiltrate responsible for graft destruction was found. The results show that indefinite parathyroid allograft survival cannot be achieved by short-term immunosuppression alone. Whether the combination of an additional graft pretreatment and immunosuppression has an impact on graft function will be further examined.

Human monoclonal IgM antibodies with apoptotic activity isolated from cancer patients

Monoclonal antibodies are accepted as ideal adjuvant therapeutic reagents for all kinds of diseases. Polyvalent (cross-linking) and low-mutated IgM antibodies (less immunogenic) are believed to be the most effective weapons against cancer. The best sources for these types of antibodies are the cancer patients themselves. Using conventional hybridoma technology, not only are fully human monoclonal IgM antibodies isolated, but also new tumor-related targets can be identified using the same experimental approach. The resulting antibodies can be used directly for therapeutic purposes without further modulation and manipulation. This report describes five newly established human monoclonal IgM antibodies; antibody LM-1 that was isolated from a patient with lung cancer, antibodies PM-1 und PM-2 that were isolated from a patient with pancreatic cancer, and antibodies CM-1 and CM-2 which were isolated from a patient with colon carcinoma. The mainly germ-line encoded antibodies are specific for malignant tissues and show only restricted reactivity with healthy cells. When tested for in vitro functional activity, all five antibodies inhibit tumor cell proliferation of carcinoma cells by inducing apoptosis.

[Induction of apoptosis by preoperative passive immunotherapy in resectable stomach carcinoma]

The antibody SC-1 is a human IGM molecule, which binds to a tumor specific receptor. This SC-1 receptor is detectable on biopsies, it is present in about 50% of gastric cancers. After binding of the antibody to the receptor the tumor cells go into apoptosis. 50 patients expressing the SC-1 receptor on their tumors have been treated with SC-1 prior to gastrectomy. In 80% of cases apoptosis induction could be demonstrated in the tumors. The only side effect of the SC-1 therapy was a reversible episode of fever during antibody infusion in 8% of our patients.

[Solid-pseudopapillary tumor of the pancreas as differential diagnosis in pancreatic tumors of the young]

AIM

The presentation of solid pseudopapillary tumors of the pancreas (SPTP) with examples of our own surgical department. SPTP occur typically in young women or in children and are for most of benign behavior. In about 5 % a malignant course with occurrence of metastases can develop.

METHODS

Diagnosis, morphological and histological findings and therapeutic approach are described in three cases. The differential diagnosis of other tumors of the pancreas is discussed.

FINDINGS

Three women (age 21, 33 and 43) with SPTP have been treated in the Department of Surgery at the University of Würzburg between 1997-1999. All tumors were resected curatively. No adjuvant treatment was performed. The follow up ranged from 31-56 months. No relapse of disease or occurrence of metastases were observed. All resected specimen revealed the typical character of SPTP with areas of solid parts and hemorrhage within the tumor. A panel of immunohistological markers (Vimentin, N-Cam, NSE, Chromogranin, Synaptophysin, Ck7, Ck19, Ck20, EMA) and expression of receptors were investigated.

CONCLUSION

The diagnosis of this rare tumor can be made clinically and intraoperatively according to its typical morphology and occurrence, predominantly in young women or in children thus helping to perform adequate surgical therapy.

Constitutive JNK activation in NIH 3T3 fibroblasts induces a partially transformed phenotype

The c-Jun N-terminal kinases (JNKs) (also known as stress-activated protein kinases or SAPKs), members of the mitogen-activated protein kinase (MAPK) family, regulate gene expression in response to a variety of physiological and unphysiological stimuli. Gene knockout experiments and the use of dominant interfering mutants have pointed to a role for JNKs in the processes of cell differentiation and survival as well as oncogenic transformation. Direct analysis of the transforming potential of JNKs has been hampered so far by the lack of constitutively active forms of these kinases. Recently, such mutants have become available by fusion of the MAPK with its direct upstream activator kinase. We have generated a constitutively active SAPK beta-MKK7 hybrid protein and, using this constitutively active kinase, we are able to demonstrate the transforming potential of activated JNK, which is weaker than that of classical oncogenes such as Ras or Raf. The inducible expression of SAPK beta-MKK7 caused morphological transformation of NIH 3T3 fibroblasts. Additionally, these cells formed small foci of transformed cells and grew anchorage-independent in soft agar. Furthermore, similar to oncogenic Ras and Raf, the expression of activated SAPK beta resulted in the disassembly of F-actin stress fibers. Our data suggest that constitutive JNK activation elicits major aspects of cellular transformation but is unable to induce the complete set of changes which are required to establish the fully transformed phenotype.

Ultrastructural alterations of primary human liver sinusoidal cells in patients treated for peritonitis

Acute peritonitis is still associated with a high mortality rate. Bacterial toxins are rapidly cleared from the peritoneal cavity and may induce general sepsis. The hepatic sinusoidal cells are part of the primary defence against these toxins. The object of this study was to examine ultrastructural alterations of human sinusoidal liver cells from patients undergoing surgical treatment for peritonitis. Liver specimens, obtained from five patients treated with programmed interval peritoneal lavages for peritonitis, were analyzed by electron microscopy. Despite interindividual differences in etiology of peritonitis, the detected ultrastructural alterations displayed a high degree of similarity. Kupffer cells displayed enhanced phagocytotic activity. Numerous Kupffer cell-lymphocyte contacts were observed. Notably, the morphological appearance of the endothelial cells resembled that of an activated phagocytotic cell. The ultrastructural alterations peaked on day 7, and regressed during the course of treatment. Our findings demonstrate that major changes occur in the ultrastructural appearance of both Kupffer cells and sinusoidal endothelial cells in patients with acute peritonitis treated successfully with programmed interval peritoneal lavages. Our data suggest that in peritonitis, a septic spread of toxins and antigens may be modulated by sinusoidal liver cells.

Success in treatment of complicated diverticular disease is stage related

The clinical stage of disease is one of the many factors affecting outcome after treatment for complicated diverticular disease. We retrospectively assessed surgical results during the period 1994-1999 in 406 patients with complicated diverticular disease, according to the stage of disease, surgical technique, postoperative complications, and mortality. Single-stage resection and primary anastomosis were performed safely in most patients with stage I or II disease. Severe complications were rare in stage I but increased in incidence with higher stages. Patients with stage III are a high-risk group. This stage often requires a two-stage procedure (primary anastomosis and protective ileostoma or the Hartmann procedure). Despite these measures, many severe complications occurred in stage III.

[Adjuvant immunotherapy of stomach carcinoma with antibody-induced apoptosis]

The human monoclonal antibody SC-1 was isolated from a patient with a diffuse-type adenocarcinoma of the stomach and induces apoptosis of stomach carcinoma cells by binding a stomach-carcinoma-associated isoform of CD55/DAF-B. In a first clinical trial with 20 patients with poorly differentiated stomach adenocarcinoma of diffuse-type received 20 and 30 mg of purified SC-1 antibody intravenously, followed 24 or 48 h later by gastrectomy and lymphadenectomy. In 90% of the cases a significant induction of apoptotic activity was measured in primary tumors as compared with earlier biopsy material and in 50% of the patients a significant regression of tumor mass could even be determined histopathologically. No toxic crossreactivity was observed with normal tissue or organs of patients. These data show, that the human monoclonal antibody SC-1, which induces tumorspecific apoptosis, can be successfully used for adjuvant therapy.

Adjuvant therapy for gastric adenocarcinoma with the apoptosis-inducing human monoclonal antibody SC-1: first clinical and histopathological results

In a first clinical trial with the apoptosis-inducing human antibody SC-1 eight patients with poorly differentiated stomach adenocarcinoma of diffuse-type received 20 or 30 mg of purified SC-1 antibody intravenously, followed 24 or 48 h later by gastrectomy and lymphadenectomy. In seven cases a significant induction of apoptotic activity was measured in primary tumors as compared with earlier biopsy material and in five patients a significant regression of tumor mass could be determined histopathologically. No toxic crossreactivity was observed with normal tissue or organs of patients.

[Primary extragenital manifestation of a malignant mixed Mullerian tumor of the major omentum]

Malignant mixed Müllerian tumours (MMMT) are tumours of the female genital tract which rarely occur in extragenital sites. We report a case of a 46-year-old female with MMMT with primary occurrence in the greater omentum. Only 19 cases of primary extragenital manifestations of this tumour are described in literature. The clinical appearance, diagnosis, therapy, histological evaluation and histogenesis are discussed.