摘要:

Several laboratories have introduced the lacZ gene into 9L cells to improve the usefulness of this already popular rat brain tumor model. However, these laboratories were not concerned about possible changes in the phenotypic characteristics of the 9L cell line which can be induced by the selection of lacZ-expressing clones. Here, we describe a method for introducing the lacZ gene into 9L cells without selective cloning. The 9L parent cells (passaged the same number of times) and 9L/lacZ cells were compared in a number of tests and found to have the same phenotype. Specifically, they had the same sensitivity to radiation from external γ or internal β radiation, the same growth rates with or without frequent media changes and the same patterns of growth in rat brain. We demonstrated that the 9L/lacZ cells could be sorted from dissociated tumors by flow cytometry and the percentage of nonmalignant versus malignant cells determined. These percentages were variable from rat to rat. The colony-forming efficiency could be determined on the basis of whole tumor or, by using the percent of lacZ-positive cells, on the basis of malignant cells in a tumor. These novel approaches should render the 9L tumor model even more usefu

ISSN:1010-4283    

DOI:10.1159/000218046

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

The use of PSA in the diagnosis of prostate cancer is controversial. This is due to false-positive results caused by benign prostatic hyperplasia (BPH). Different forms of circulating PSA have recently been described. Initial studies indicate that the fraction of free PSA is lower in prostate cancer than in BPH, therefore suggesting that its measurement could be of some diagnostic value. We have assessed the serum value of the percentage of free/total PSA in the differential diagnosis of BPH and prostate cancer. The levels of PSA and free PSA (DELFIA) were measured in 145 BPH patients and 56 prostate cancer patients. Free PSA is a small fraction of PSA, and significantly lower levels are being found in prostate cancer. In those patients with a PSA level between 2 and 25 μg/l, the determination of the percentage of free PSA increased the diagnostic efficiency of PSA, while reducing the number of negative biopsies. We conclude that free PSA may be a useful marker for the diagnosis of prostate cancer

ISSN:1010-4283    

DOI:10.1159/000218047

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

Human breast cancer cells were cultured together with their metastatic target, bone tissue, to analyze possible growth promotion effects. The coculture of human osteosarcoma cells (TE-85) with human mammary carcinoma cells (ZR-75.1) resulted in up to 8.4-fold stimulation of proliferation of the breast tumor cells. Cell contact of the two cultures was permitted through the channels of Nuclepore filters. However, physical contact turned out not to be necessary, since the proliferative stimulus was also mediated by a bone-derived diffusible factor. Conditioned medium (CM), collected from human primary bone cultures, enhanced the rate of proliferation of several breast tissue cell lines (ZR-75.1, BT-20, HBL-100), while some lines were not affected by osteoblast CM. Breast tissue lines responding to bone CM express low to intermediate levels of the c-erbB-2 gene, in contrast to nonstimulated lines which overexpress the gene. Recent observations of metastatic spread in breast cancer patients suggest a distinctive pattern of secondary tumor distribution in association with c-erbB-2 protein expression. Bone tissue seems to be a preferential target for metastases of c-erbB-2-negative breast tumors.

ISSN:1010-4283    

DOI:10.1159/000218048

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

This article describes the recognition of a special membrane antigen of the rat squamous cell carcinoma (SCC) by a monoclonal antibody (mAb), UB23, and the characterization of the UB23 antigen expression in the implanted primary and metastatic SCC in rat models. The mAb UB23 was raised against the FF6 tumor, a well-differentiated rat SCC, and it recognized the 120- to 130-kD cell surface antigen in FF6 tumor cells. The UB23 antigen was found in frequently observed small ‘basal’ cells but not in keratinocytes, and an increased expression was seen in the cells at the interface with peritumoral stroma in both the implanted primary FF6 tumors and metastases. These results indicated that the UB23 antigen is closely related with the cell differentiation and invasion of FF6 cells, and could be useful for analyzing the mechanism of differentiation, invasion and metastasis of SCC in animal mod

ISSN:1010-4283    

DOI:10.1159/000218049

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

Aberrant glycosylation of mucins on the surface of adenocarcinomas leads to exposure of novel tumor-associated epitopes potentially recognizable by the immune system. Monoclonal antibodies (mAbs) have been developed against some of these epitopes. One such mAb, denoted CC49, recognizes the tumor-associated glycoprotein TAG-72. Most adenocarcinomas, including breast, colon, ovarian, prostate, and gastric, express some form of this molecule, recognizable by the CC49 antibody. The widespread distribution of the antigen on transformed cells makes the CC49 mAb a potentially powerful tool in numerous immunotherapy contexts. In the course of our studies with CC49 and certain of its molecularly engineered derivatives, we screened a number of human hematopoietic cell lines for TAG-72 expression by flow cytometry using CC49. We found that the T-cell line, Jurkat, had a higher level of CC49 mAb binding than any of the carcinoma cell lines previously evaluated in our laboratory. In addition, the myelo-monocytic cell line Tf-1 and the erythroleukemia cell line K562 were also positive for CC49 mAb binding by flow-cytometric analysis. However, peripheral blood lymphocytes and certain other hematopoietic cell lines were not able to bind the CC49 mAb. Immunoblot analyses of cell extracts from the CC49 reactive lines indicated distinct protein species reactive with the CC49 antibody. In some instances, cells expressing these reactive proteins were susceptible to antibody-dependent cellular cytotoxicity using a chimeric derivative of the CC49 antibody. These results indicate that the cell membrane expression of molecules recognized by CC49 extends beyond adenocarcinomas to certain cell lines of hematopoietic origin.

ISSN:1010-4283    

DOI:10.1159/000218050

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

Single and fractionated doses of radioimmunotherapy (RAIT) and standard chemotherapy (0.6 mg 5-FU/day and 0.36 leuco-vorin/day on days 1–5) result in decreases in vascular permeability (VP) in the GW-39 human colonic xenograft. The effect of a single dose of RAIT (MN-14 anticarcinoembryonic antigen, Mu-9 anticolon-specific antigen, PAM-4 anti-MUC-1, RS-7 and RS-11 antiepithelial glycoprotein labeled with 131I) has also been evaluated in 10 other tumors. Fourteen days after a fixed 1,500-cGy dose of RAIT, 3 colonic tumors (LS174T, HT-29 and MOSER) all exhibited decreases in VP (58, 75 and 70%, respectively). Two colonic (LoVo and GS-7) and 1 breast tumor (MDA-468) did not exhibit any change in VP, and 1 lung (CALU-3), 1 cervical (ME-180), 1 pancreatic (CaPan-1) and 1 breast cancer line (ZR-75) exhibited increases in tumor VP (214, 289, 170 and 139%, respectively). The differences in VP response to RAIT do not appear to be related to the type of tumor, the size of tumor or the antigen being targeted by RAIT. The differences in tumor VP response to RAIT are discussed in terms of the ability to achieve significant tumor accretion of a second dose of radioantibody on a multiple-dosing regimen. We have begun to investigate the mechanism(s) which regulate the varying responses of tumor VP to RAIT by assessing the role that nitric oxide plays. Administration of arginine, a substrate for nitric oxide synthase, results in increases in both baseline and RAIT-modified VP in GW-39 and ME-180 tumor

ISSN:1010-4283    

DOI:10.1159/000218051

出版商:S. Karger AG    

年代:1997

数据来源: Karger

ISSN:1010-4283    

DOI:10.1159/000218052

出版商:S. Karger AG    

年代:1997

数据来源: Karger

ISSN:1010-4283    

DOI:10.1159/000218053

出版商:S. Karger AG    

年代:1997

数据来源: Karger

ISSN:1010-4283    

DOI:10.1159/000218054

出版商:S. Karger AG    

年代:1997

数据来源: Karger

ISSN:1010-4283    

DOI:10.1159/000218045

出版商:S. Karger AG    

年代:1997

数据来源: Karger