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Purpose: To improve immunological defense of tumors, we investigated the effect of intraoperative vaccination with IL-12 cDNA transfected cells in an autologous mouse tumor model. Methods: Tumors derived from autologous Lewis lung carcinoma cells were established in C57/BL6 mice. At day seven, the tumors were surgically removed. Simultaneously, the mice were vaccinated intraoperatively with Lewis lung carcinoma cells transfected with an IL-12-encoding pRSC construct or with the empty plasmid, or with dead cells either intrasplenically (i.s.) or subcutaneously (s.c.). Control mice did not obtain vaccination. Tumor re-growth, survival, and metastasis were monitored. Mice with no tumor re-growth underwent a second tumor implantation. The same parameters were examined. Results: After tumor resection and vaccination tumors reappeared in 60.0% of the animals of the control group. Lowest tumor reoccurrence rates of 41.4 and 43.5% were seen in animals receiving IL-12 pRSC cells either i.s. or s.c. Survival tended to be enhanced in all vaccinated animals compared with the control group. Following R0 tumor resection, the rate of tumor-free survivors was highest when IL-12 pRSC cells were given i.s. (73%, control 45%). 37-59% of the mice of the therapy groups did not develop a tumor, that is, they were tumor-free survivors. These mice underwent a second tumor implantation 120 days after tumor resection and vaccination. Tumor growth was significantly delayed in mice receiving IL-12 pRSC cells. Conclusions: Intraoperative autologous whole-cell vaccination is practicable and proved to have anti-tumor potential, and therefore, it could be an additional option in adjuvant cancer therapy. [ABSTRACT FROM AUTHOR]

Purpose: We investigated the effect of intraoperative intrasplenic or subcutaneous vaccination with modified tumor cells on tumor progression in a mouse model. Methods: Pre-established B16 melanomas on C57/Bl6 mice were surgically removed; mice were vaccinated intraoperatively with B16 cells transfected with an IL-12-encoding pRSC construct, the empty plasmid, or B16 frozen cells. Cells were given either intrasplenically or subcutaneously. Intrasplenic effects of vaccination were examined along with survival data. Mice without tumor recurrence underwent a second tumor implantation. Results: Animals administered IL-12 pRSC cells showed significant alterations in the spleen, such as higher percentages of (activated) CD4+ and CD8+ T cells and tumor-specific CD4+ T cells among splenocytes. The tumor recurrence rate after resection ranged from 13 to 36%. Cases with recurrent tumors in particular benefited in all therapy groups, resulting in enhanced (tumor-free) survival, reduced tumor growth and lower metastasis rates. Following macroscopic complete tumor resection, the optimum outcome resulted from vaccination with IL-12 pRSC cells into the spleen and subcutaneously administered frozen cells. Survival times were enhanced in all therapy groups after tumor reimplantation, although results were not significant. Conclusions: Intraoperative whole-cell vaccination with autologous tumor cells yields promising data, and could be considered as a future option in adjuvant cancer therapy. [ABSTRACT FROM AUTHOR]

Polymorphic glutathione S-transferase (GST) enzymes are involved in the metabolism of xenobiotics. They are of particular interest when studying disease susceptibility and adverse drug responses. The present work deals with the genetic polymorphisms and expression of the five GST classes (alpha, mu, pi, theta and zeta) in human lung and hepatocyte cell lines. We have determined their bioavailability for in vitro approaches. Common genetic polymorphisms of GSTM1 (*0, null), GSTT1 (*0) and GSTP1 (*A/*B, I105V) are detectable. The frequencies of the polymorphisms are within the expected range for a Caucasian population with one exception. The GSTM1*0 allele is 1.5-fold more frequent in lung cell lines. GST mRNAs are frequently but not uniformly distributed among unstimulated in vitro conditions. Lung cell lines show an approximately six-fold higher total GST transcript expression than hepatocyte cell lines. Additional GST transcripts have been identified for GSTT1; they represent alternative new splicing variants that occur in cancerous cell lines and in healthy lung tissue and blood. GST enzyme activity is mainly influenced by GSTP1. The activity promoted by 1-chloro-2,4-dinitrobenzene is significantly correlated to the GSTP1 mRNA expression level (R2=0.77, P<0.001). Individual human cell lines thus express GST isoenzymes in a similar pattern to human tissue. The most common genetic polymorphisms are present among the cell lines and have to be considered for in vitro stimulation approaches in a combinatory pattern. [ABSTRACT FROM AUTHOR]

CD97, an epidermal growth factor (EGF)-TM7 receptor, is not restricted to hematopoetic and carcinoma cells but is also found on smooth muscle cells (SMC). We have examined its location and biochemical structure in various normal and tumorigenic SMC-containing tissues. SMC of the urinary bladder, lung bronchi and bronchioles, myometrium, and gastrointestinal tract were immunohistologically stained by using monoclonal antibodies (mabs) to the CD97 stalk region (CD97stalk). Mabs directed against an N-glycosylation-dependent epitope within the EGF-domains (CD97EGF) did not bind to normal SMC. Vascular SMC, which was also CD97EGF-negative, showed further CD97 heterogeneity. Only a few, if any, SMC from the aorta or elastic arteries of the systemic circulation were positive for CD97 mRNA and therefore also for CD97stalk. CD97stalk-positive SMC were slightly more numerous in muscular and peripheral arteries. In contrast, most venous SMC expressed CD97stalk. A comparison with other SMC molecules revealed a similar but not identical staining pattern for CD97stalk and desmin. Further CD97 heterogeneity was observed during SMC transformation. All leiomyomas ( n=5) and nine out of 21 leiomyosarcomas were positive for both CD97stalk and CD97EGF. As expected, CD97EGF-positive SMC tumors expressed partly N-glycosylated CD97. Seven out of 21 leiomyosarcomas were completely devoid of CD97. Thus, CD97 showed variable expression in vascular and biochemical modification in tumorigenic SMC, suggesting that the function of the molecule is specific for the SMC subtype. [ABSTRACT FROM AUTHOR]

EMR2 and CD97, members of the epidermal growth factor (EGF)-TM7 family, show a very high homology. CD97, whose expression is closely related to clinical tumor stage in colorectal carcinomas, potentially functions as an adhesion molecule. Nothing is known about the presence of EMR2 in these tumors. We systematically examined the expression of EMR2 in colorectal carcinoma cell lines and adenocarcinomas. Of 18 cell lines, 10 were only slightly positive for EMR2 according to flow cytometry. Various EMR2 splice variants, including a new isoform, have been detected at the mRNA level. EMR2 expression did not correlate with in vitro migration or invasion capacity of the cell lines. Normal colorectal epithelial cells were EMR2 negative. In contrast to CD97, which is found in most colorectal adenocarcinomas, only 8 of 81 of these tumors expressed EMR2. No correlation was found between EMR2 expression and clinicopathological parameters of the tumors. In summary, a significant but low number of colorectal carcinomas are positive for EMR2, indicating different roles for this molecule and CD97 in these tumors. [ABSTRACT FROM AUTHOR]

We have recently described cytokeratin-positive (CK+) and cytokeratin-negative (CK–) microvascular endothelial cells (MVECs) in the bovine corpus luteum. The two phenotypes show a different expression and release of adhesion molecules and cytokines. Since secretion of mediators is specifically regulated by the electrophysiological membrane parameters, this report will compare voltage-dependent potassium (K+) channels in the two cell types cultured under the same conditions. CK+ and CK– MVECs derived from the microvascular bed of one organ differ in their K+-channel characteristics. In CK– MVECs, an inwardly rectifying K+ current was discovered, showing the characteristics of the Kir2.1. CK+ MVECs displayed a voltage-dependent K+ current that activates rapidly on depolarization and inactivates very slowly, and is associated with a member of the Kv family. The mRNA for Kir2.1 was identified by RT-PCR in CK– and CK+ MVECs, but there was no evidence of Kv1.4 mRNA in either of them. The function of Kir2.1 in CK– MVECs might be induced during cultivation, whereas CK+ MVECs appear to be more resistant to environmental conditions and do not express an inward current. [ABSTRACT FROM AUTHOR]

Among the five classes of G protein-coupled receptors (GPCRs) adhesion- GPCRs (aGPCRs) comprise the second largest but most mysterious one. Its 33 human members are giant membrane proteins with extracellular N-termini up to 6,000 amino acids long containing numerous and diverse domains potentially involved in adhesion. Although most of the aGPCRs are orphans, several studies in the past five years revealed interesting facets of their unusual and complex molecular structure and signal transduction as well as essential functions in developmental, neurophysiological and immunological processes. [ABSTRACT FROM AUTHOR]