Prostaglandins and activation of AC/cAMP prevents anoikis in IEC-18.

Recent data indicates that chronic inflammation of the intestine such as Crohn's or ulcerative colitis puts those individuals at heightened risk for colorectal adenocarcinoma. In this study, we examine the effect of the inflammatory mediator PGE(2) and associated signalling on detachment-induced cell death (anoikis) in intestinal epithelial cells. Treatment of detached IEC-18 with 0.01-0.05 microM PGE(2) increased cell viability as well as induced aggregation. As EP4 prostaglandin receptors on IEC are coupled to adenylate cyclase, we next treated cells with agents that promote cAMP signalling (Forskolin, dbcAMP, and etazolate), all of which promoted IEC aggregation as well as survival. We next treated detached IECs with specific inhibitors of adenylate cyclase or PKA, which accelerated anoikis. To explore the mechanism of cell-cell adhesion, we next treated detached IECs with an anti-E-cadherin blocking antibody which dispersed aggregates induced by dbcAMP, and an adenovirus expressing a dominant negative E-cadherin (EcadDeltaEC) prevented aggregate formation. Interestingly EcadDeltaEC prevented aggregation of IEC induced by dbcAMP but did not significantly reduce viability. This suggests that cAMP signalling is important in both aggregate formation and promoting viability but these are distinct events. Taken together, these data support a mechanism whereby elevated PGE(2) levels characteristic of colitis prevent anoikis by activating an AC-, cAMP-, and PKA-dependent signalling pathway. The delay of apoptosis by PGE(2) may be one mechanism by which inflammation may contribute to carcinogenesis.

Endogenous IL-1 and type II IL-1 receptor expression modulate anoikis in intestinal epithelial cells.

We previously reported that IL-1beta and the decoy receptor for IL-1 (IL-1RII) are expressed by intestinal epithelial cells (IEC) during detachment-induced cell death, or "anoikis." We now investigated whether IL-1 regulates anoikis. Skewing the balance in favor of IL-1, by blocking IL-1RII or by adding IL-1beta to detached rat IEC-18 cells, reduced cell death. The protective effect of anti-IL-1RII was reversed by blocking IL-1beta, confirming the anti-apoptotic effect was due to endogenous IL-1beta. Added IL-1beta also rescued cells from anoikis and was associated with considerable aggregation of the detached cells. Aggregate formation and the anti-apoptotic effect of added IL-1beta were prevented by blocking E-cadherin, indicating that IL-1 promoted aggregation and indirectly, survival. On the other hand, treating detached cells with IL-1beta and an anti-beta(1) integrin antibody abolished the protective effect of IL-1beta but not the aggregates. We conclude that the anti-apoptotic effect of IL-1 is mediated through a beta(1) integrin-dependent event secondary to cell-cell adhesion. This illustrates a previously uncharacterized role for IL-1 in the intestine wherein this cytokine may facilitate the preservation of the epithelial monolayer integrity.

Monocyte chemoattractant protein-1 production by intestinal epithelial cells in vitro: a role for p38 in epithelial chemokine expression.

The intestinal epithelial cell (IEC) represents the first cellular barrier to infection. Consistent with this sentinel role, IEC are known to produce a variety of chemokines in response to bacterial infection or proinflammatory cytokines. These chemokines act as potent leukocyte activators and chemoattractants in vivo. In this report, we begin to characterize the regulation of expression of the chemokine monocyte chemoattractant protein-1 (MCP-1) in the rat small intestinal IEC-18 line. Following stimulation with either interleukin-1beta (IL-1beta) or lipopolysaccharide (LPS), IEC-18 cells produced MCP-1, with IL-1 proving a more effective stimulus than LPS at both the mRNA and protein levels. Expression of MCP-1 due to either stimulus was inhibited by tyrosine kinase inhibitors, prompting us to investigate potential phosphotyrosine-dependent targets responsible for MCP-1 expression. We detected activation of p38, a member of the mitogen-activated protein kinase family, following either IL-1 or LPS treatment. Specific inhibition of this kinase using the compound SB203580 caused a destabilization of MCP-1 mRNA. These data point to a role for p38 in the regulation of MCP-1 mRNA expression by the IEC.

Diet and breast cancer: review of the epidemiologic literature.

The relationship between diet and breast cancer has been analyzed by animal, ecologic, migrant, and epidemiologic studies. The 14 cohort and 33 case-control studies that have been published to date are reviewed in this article. Factors considered in these studies include caloric intake, as well as fat, protein, fiber, beta-carotene, and vitamin E and C consumption. The results of the published studies are summarized, and the point estimates of the risks corresponding to the highest category of consumption as compared to the lowest are presented in figures. Some of the disagreements among studies could be explained by the methodologic difficulties inherent in dietary investigations, such as the establishment of an accurate dietary history, or insufficient diversity in exposure. Further studies taking these points into account and minimizing biases inherent to a case-control design might help to elucidate the relationship between diet and breast cancer, and to define dietary recommendations. Only large long-term cohort studies such as are now in progress can help to resolve the still unanswered questions concerning the contribution of these dietary factors to the risk of breast cancer. We suggest the establishment of new dietary cohorts and the continued follow-up of the existing cohorts.

Interactive computer-based programs for a cancer learning center.

This paper describes the design and evaluation of a computer-based instruction (CBI) program that was integrated into a multidisciplinary cancer curriculum at the Medical College of Pennsylvania. Instruction took place in a cancer learning center. Modules contained literature, posters, slide sets, videocassette films, and "see, touch, and feel" models to teach and practice breast, testicular, rectal, laryngeal, and colonoscopic examinations. The CBI (programmed on HyperCard) contained tutorials divided into three levels of learning objectives: level one, epidemiology and prevention; level two, diagnosis and staging; and level three, management and prognosis. Simulated cases and test items were developed for each level. To evaluate students' perceptions of the program and provide them with feedback about their performances, the authors designed a questionnaire, held a focus group, and developed a built-in tracking system for the CBI. Results showed that the program was well received, the students answered the test items correctly, and the students wanted more time to study cancer. A description of some of the problems encountered with technology and equipment is provided for faculty who may be interested in designing and implementing similar CBI programs.

Viewpoints and concerns of a clinical trial participant.

Most practicing oncologists are committed to the concept of prospective clinical trials but, because of multiple logistic and perceptual deterrents, actually enter only a small portion of their patients into such studies. Physician concerns include discomfort with placebo or "no treatment" randomizations, the burden of cumbersome monitoring of protocol patients, and fear of displeasing referring physicians. Patients have difficulty accepting the uncertainty of randomized trials, particularly those with a placebo arm. They resent the inconvenience and expense of extra visits and studies associated with protocol participation. Informed consent documents are often complex and their intent misconstrued by patients. Rigorous eligibility requirements, although necessary for accurate analysis, reduce accrual. Multiplicity of protocols, with the resulting necessity to prioritize, rapid closure of Phase II studies for common tumors, and negative public attitudes reinforced by the media are significant deterrents to clinical trial participation. Increasing accrual is a daunting challenge to the physician. Simplification of burdensome data collection, consent forms, and institutional review board procedures will reduce reluctance to participate. Most important, physicians must be educators, emphasizing the advantages of clinical trials to their patients and their families, their colleagues, and the public.

Plasma thrombospondin levels in patients with gynecologic malignancies.

BACKGROUND: Thrombospondin is a high molecular weight glycoprotein, originally described as a secretion product of platelets, that functions as an adhesive protein in cell-cell and cell-substratum interactions. It promotes metastases in the murine model. Plasma thrombospondin has been shown to be elevated in patients with disseminated breast, lung, and gastrointestinal malignancies. METHODS: Blood samples were collected by venipuncture into cubes containing ethylenediamine tetraacetic acid as anticoagulant. They were placed on ice immediately and centrifuged under refrigerated conditions. Plasma was removed and frozen until thrombospondin was quantitated by a competitive enzyme-linked immunosorbent assay. Wilcoxon's two-sample rank-sum test was used to evaluate differences between the patient and control groups. RESULTS: The median plasma thrombospondin level was significantly higher in the patient group compared with the control group, and it was directly correlated with stage of disease. There was no correlation between platelet count and thrombospondin level. CONCLUSIONS: Tumor-synthesized thrombospondin could explain the elevated levels in the patent group and also the observation of the correlation between the thrombospondin level and tumor burden. Its function as an adhesive protein may allow it to act as the mediator of metastases. thrombospondin may promote or mediate the metastatic process through its function in cell adhesion.

Thrombospondin levels in patients with malignancy.

Thrombospondin (TSP), a large glycoprotein present in platelets, and various normal and tumor tissues, has recently been shown to promote cell adhesion and platelet aggregation. Most importantly because TSP has been shown to promote metastasis of melanoma tumor cells to the lung in a murine model (1) and since thromboembolic events commonly occur in patients afflicted with metastatic tumors, we explored the role of TSP in human cancer by measuring TSP blood levels in patients with various malignant neoplasms. Blood TSP levels were measured by indirect enzyme-linked immunoadsorbent assay (ELISA) from 20 control subjects, 22 patients with gastrointestinal (GI) cancer, 18 patients with breast cancer, and 17 patients with lung cancer. Control subjects consisted both of healthy subjects and acutely ill patients with no malignancies. TSP levels of both healthy and acutely ill controls were found to range between 245-440 ng/ml with a mean of 365 ng/ml. In contrast, elevated levels of TSP greater than the mean value of 400 ng/ml for controls ranging between 590-3,650 ng/ml were found in 20/22 (91%) patients with GI malignancies, 13/18 (72%) patients with breast cancer, and 15/17 (88%) with lung cancer. Mean TSP levels of GI, breast, and lung cancer patients were 3, 2, and 3 fold greater than controls, respectively. Increased blood TSP levels in patients were not due to increased levels of platelets since both control and patient groups had platelet counts within the normal range. These results suggest that TSP may play a role in tumor cell metastasis in man and could serve as a blood marker for metastasis.

New findings in treatment of colon cancer.

Patients with colon cancer involving regional lymph nodes (stage C disease) have a 5-year survival rate of only 30% to 40%, and the majority die of recurrent disease. Recent trials have shown increased survival rates with postoperative use of fluorouracil plus levamisole. The authors discuss these findings and the implications on treatment recommendations for stage C colon cancer.

Treatment of metastatic colorectal carcinoma. Recent advances in use of fluorouracil.

Fluorouracil (Adrucil) has been used for more than 20 years to treat metastatic colorectal carcinoma and has provided significant palliation of symptoms to some patients. Investigators are attempting to exploit pharmacologic aspects of fluorouracil that will provide further benefits. Prolonged infusion of the drug appears to overcome the problems of its brief half-life and the small percentage of cancer cells that are susceptible to the drug at any one time. The addition of leucovorin increases fluorouracil's ability to inhibit thymidylate synthase and thus colon cancer cell replication. It is hoped that the increased response rates produced by these advances will produce increased survival rates as well.

Aggressive management of cancer in the elderly.

Age per se is not a contraindication to the aggressive management of cancer. Screening, accurate staging of disease, and specific antineoplastic therapy are as effective in lowering cancer mortality in the elderly as they are in younger groups. Treatment programs should be guided by physiologic rather than chronologic age.

Specific immunoadsorption of IgG antibody in a patient with chronic lymphocytic leukemia and autoimmune hemolytic anemia. A new form of therapy for the acute critical stage.

Progressive and severe autoimmune hemolytic anemia developed in a patient with chronic lymphocytic leukemia (CLL) despite treatment with chlorambucil, high doses of corticosteroids and attempts to transfuse packed red blood cells. Splenectomy was not performed because of severe coronary artery disease. Direct antiglobulin tests revealed a warm red blood cell autoantibody of IgG-type with anti-e specificity. The patient was treated by extracorporeal immunoadsorption of plasma IgG using a cell separator and protein A as the immunoadsorbent. The patient responded by an increase in the hemoglobin levels and platelet counts after two treatments. Specificity of the procedure was shown by a decrease in the serum IgG and by the demonstration of the same reactivity to ficin-treated reagent red blood cell panel of the eluate from the protein A. Antibody titers of the patient's red blood cell eluate decreased from 1:128 to 1:64 and eventually the anti-e specificity was lost. This is a report of a novel approach to treatment of the acute phase of an autoimmune hemolytic anemia.

Fatal interstitial pneumonitis following high-dose intermittent chlorambucil therapy for chronic lymphocyte leukemia.

Interstitial lung disease has been reported in association with numerous alkylating agents and other chemotherapeutic drugs. Chlorambucil has only rarely been implicated in this complication. We report a case of a 74-year-old man with chronic lymphocytic leukemia who received high-dose intermittent chlorambucil and prednisone every two weeks. Following several of these courses of therapy, respiratory distress occurred 9 to 12 days after the chlorambucil was given. During the final episode, open lung biopsy was performed and demonstrated typical changes of drug-induced pneumonitis, with interstitial infiltrates and fibrosis and proliferation of type II alveolar lining cells.

Pancreatic pseudocyst simulating dilated biliary duct system on computed tomography.

A case of pseudocyst simulating the biliary ductal system is reported. Several CT findings indicate that the biliary system was not involved: (a) no dilatation of the more proximal intrahepatic biliary radicles; (b) the gallbladder was not distended; (c) lucency extending to the left at the level of the pancreas; (d) a position more medial and anterior than anatomic for the distal common bile duct.

Continuous culture of normal adult mammalian hepatocytes exhibiting parenchymal functions.

Past in vitro studies of liver-cell functions have been performed on nonproliferating primary cells or serially propagated hepatic monolayers of neoplastic or fetal origin. We optimized conditions for the selective culture of adult rabbit and canine liver parenchymal cells and presently have four differentiated proliferating monolayer strains. At the 30th passage level these hepatic cultures still display the specific liver parenchymal functions of albumin and fibrinogen synthesis as well as tyrosine aminotransferase activity. Optimization of the conditions for hepatocyte culture was monitored by [3H]thymidine incorporation. Albumin and fibrinogen synthesis were measured by bioradioimmunoassay and tryosine transaminase activity by a modification of Diamondstone's assay. Albumin and fibrinogen synthesis were correlated with hepatocyte growth kinetics.

Cellular and humoral immunity in non-Hodgkin's lymphoma: correlation of immunodeficiencies with clinicopathologic factors.

Immune function was evaluated in 28 non-Hodgkin's lymphoma patients in an attempt to correlate the occurrence of immunodeficiency with the prognostic clinicopathologic factors, lymph-node histology, and clinical stage of disease. Anergy to a battery of recall antigens occurred infrequently (4/28) and only in patients who had Stage IV disease (4/8) (p = less than .004), but did not correlate with lymph-node histology. In contrast to anergy, cellular immunodeficiencies were often detected by lack of response to keyhole limpet hemocyanin immunization in patients regardless of stage. Reductions in at least two of three Ig fractions were found in a third of the patients, with, again, a significantly greater incidence in Stage IV patients (p = less than .005). No significant correlation with histologic type was possible. The response to phytohemagglutinin in vitro was reduced in the patients, but this was of no correlative value.