Biomedical subjects

B M Kacinski

Publications and source records attributed to B M Kacinski.

At least 55 records · Page 3Linked to original sources

PubMed1994

Post-transcriptional regulation of c-fms proto-oncogene expression by dexamethasone and of CSF-1 in human breast carcinomas in vitro.

The c-fms proto-oncogene encodes the receptor for a hematopoietic growth factor, CSF-1. Recently, the importance of c-fms and its ligand CSF-1 in malignancies of non-hematopoietic origin, such as breast, ovarian, endometrial, pulmonary, and trophoblastic cancers has been recognized. We have previously shown that glucocorticoids induce a large increase in c-fms mRNA and protein levels in breast carcinoma cell lines. In this report, we investigate the mechanism underlying such c-fms overexpression by dexamethasone. We show that dexamethasone treatment of two breast carcinoma cell lines (BT20-c-fms expressor, and SKBR3-co-expressor of both c-fms and CSF-1) does not increase the rate of c-fms gene transcription, suggesting a post-transcriptional mechanism of regulation of c-fms expression by dexamethasone. The effect of protein synthesis inhibition was studied to help determine whether there was a role for intermediary regulatory proteins in the regulation of c-fms expression. We find that several protein synthesis inhibitors interfere with dexamethasone induction of c-fms transcripts, suggesting the existence of regulatory proteins. These regulatory proteins do not appear to be constitutively expressed, as we show no effect of protein synthesis inhibition on c-fms transcript expression in resting BT20 cells. These findings suggest that the putative regulatory proteins are induced by dexamethasone. Furthermore, the addition of a protein synthesis inhibitor, pactamycin, to dexamethasone-treated BT20 cells results in a decrease in c-fms mRNA stability.(ABSTRACT TRUNCATED AT 250 WORDS)

Amidohydrolases↗

PubMed1994

A polymerase chain reaction-based microsatellite typing assay used for tumor cell line identification.

In this report we describe the application of a polymerase chain reaction (PCR)-based DNA typing assay to the analysis of tumor cell line identity. We have applied the technique to analyze four tumor cell lines purchased from the American Type Culture Collection (SK-OV-3, SK-BR-3, OVCAR, HeLa) and four lines isolated from the ascites fluids of ovarian cancer patients (YAOVBIX1, YAOVBIX3, OC194, and OC346). In this assay, three polymorphic tetranucleotide microsatellite loci (GABARB1, TH01, and HPRTB) were amplified from tumor cell line DNAs in radioactive PCR-reactions. The products were resolved in polyacrylamide gels and exposed to film to produce individual-specific patterns for five of the cell lines (HeLa, SK-BR-3, OVCAR, YAOVBIX3, and OC194). However, three of the cell lines, SK-OV-3, YAOVBIX1, and OC436 had identical "fingerprints" at all three loci. The probability that the observed profile match could occur between three randomly selected heterologous cell lines was calculated to be 1.32 x 10(-13). On the basis of this analysis, we have identified two independent cross-contamination events involving the SK-OV-3 ovarian adenocarcinoma cell line. The PCR-based analysis of tetranucleotide microsatellite loci is technically straightforward and produces discrete allelic bands associated with known population frequencies, allowing for the unequivocal interpretation of typing patterns.

Adenoma↗

PubMed1993

Macrophage colony-stimulating factor release and receptor expression in bone cells.

Colony-stimulating factors (CSF) may play a role in bone resorption. To examine whether osteoblasts secrete colony-stimulating activity (CSA) in response to parathyroid hormone (PTH) and parathyroid hormone-related peptide (PTHrP), conditioned medium (CM) from ROS 17/2.8 cells and primary rat osteoblasts were examined for induction of clonal growth of cultured rat bone marrow cells. Untreated cells constitutively secreted CSA, which increased with PTH and PTHrP treatment. The colonies formed were principally comprised of macrophages, and preincubation of CM with antiserum to murine macrophage colony-stimulating factor (M-CSF) neutralized most of the CSA, suggesting that the osteoblast-derived CSA was predominantly due to M-CSF. PTHrP treatment upregulated steady-state M-CSF mRNA levels. To investigate a paracrine role for M-CSF in bone we examined bone tissue and cells for the M-CSF receptor c-fms using immunohistochemical techniques and demonstrated staining of mature osteoclasts both in situ and after isolation. We conclude that M-CSF is responsible for the majority of the CSA released by PTH- and PTHrP-treated rat osteoblasts. In addition we identified CSF-1 receptor expression in mature osteoclasts. These data suggest that M-CSF is a mediator of osteoblast-osteoclast interaction in PTH- and PTHrP-induced bone resorption.

Animals↗

PubMed1993

Colony-stimulating factor-1 in primary ascites of ovarian cancer is a significant predictor of survival.

OBJECTIVE: Our purpose was to determine whether the concentration of colony-stimulating factor in ascites of ovarian carcinoma is a prognostic factor for survival. STUDY DESIGN: Forty-four ascites samples from patients undergoing primary surgery for ovarian carcinoma were measured for colony-stimulating factor-1 by radioimmunoassay. Retrospective analysis of clinical data allowed comparison of accepted prognostic factors to ascites colony-stimulating factor-1 concentration for impact on survival by means of life-table analysis (Kaplan-Meier) by the Wilcoxon test and the Cox regression methods. RESULTS: In patients with advanced disease (International Federation of Gynecology and Obstetrics stages III and IV, n = 37) ascites colony-stimulating factor-1 concentration levels below a critical cutoff of 8.59 ng/ml were associated with longer overall survival (p < 0.05) and were a better predictor of survival than any other prognostic factor except zero residual disease after cytoreduction. International Federation of Gynecology and Obstetrics stage, tumor histologic type, malignant cells in fluid, grade of tumor, age, and performance status at presentation were not predictive of outcome. CONCLUSION: Colony-stimulating factor-1 in ascites may be an independent indicator of prognosis in patients with epithelial ovarian cancer.

Adult↗

PubMed1993

Posttranscriptional regulation of colony-stimulating factor-1 (CSF-1) and CSF-1 receptor gene expression during inhibition of phorbol-ester-induced monocytic differentiation by dexamethasone and cyclosporin A: potential involvement of a destabilizing protein.

Colony stimulating factor-1 (CSF-1) and its receptor (encoded by the c-fms proto-oncogene) have long been recognized as playing an important role in monocytic differentiation. However, the regulation of expression of the CSF-1 and c-fms genes during inhibition of monocytic differentiation has not been fully characterized. The present studies demonstrate that dexamethasone (dex) and cyclosporin A (CsA) resulted in inhibition of 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced monocytic differentiation of HL60 cells, as well as TPA induction of c-fms and CSF-1 transcripts. These agents also blocked TPA-induced adherence, alpha-naphthyl acetate esterase staining, and the development of a more differentiated morphology. Nuclear run-off analyses revealed no effect of either of these agents on transcription of either c-fms or CSF-1 genes in TPA-treated HL60 cells. Measurements of c-fms transcript half-life confirmed post-transcriptional regulation of c-fms transcript levels after the addition of dex or CsA to TPA, both of which resulted in a decrease in c-fms mRNA half-life. Others have suggested that TPA results in the stabilization of c-fms mRNA in HL60 cells through induction of a labile mRNA stabilizing protein. We observed, however, that the inhibition of protein synthesis by cycloheximide (CH) in this setting of early monocytic differentiation increased both c-fms and CSF-1 steady-state transcript levels. While CH had no effect on the transcription of c-fms and CSF-1 genes in TPA/dex- or TPA/CsA-treated HL60 cells, c-fms mRNA was stabilized after the addition of CH to TPA/dex-treated cells. Taken together, our results suggest the existence of a labile mRNA regulatory protein or proteins, whose actions include destabilization of both c-fms and CSF-1 transcripts after inhibition of TPA-induced monocytic differentiation by dex or CsA.

Cell Differentiation↗

PubMed1992

Changes in Na,K-ATPase gene expression during granulocytic differentiation of HL60 cells.

During granulocytic differentiation of HL60 cells, immediate reduction of ouabain-sensitive potassium flux is observed within the first 12 hours of addition of dimethyl sulfoxide (DMSO). We show that gene expression of the alpha 3 isoform of Na+,K(+)-ATPase, which encodes an ouabain-inhibitable Na+,K(+)-ATPase activity, significantly declines during the first 24 hours of granulocytic differentiation by DMSO of HL60 cells. The more common alpha 1 isoform decreases, but more gradually over 72 hours of DMSO induction. Loss of alpha 3 and alpha 1 messenger RNA (mRNA) are due to changes in mRNA decay; their transcription is not altered. alpha 3 mRNA half-life is 3 hours in HL60 cells; upon induction by 16 hours of DMSO, it decreases to approximately 2 hours. alpha 1 transcripts are less sensitive to DMSO induction, with their half-life being 3.5 hours in HL60 cells; upon induction, their half-life decreases to 3 hours. Experiments measuring protein stability confirm that alpha 3 protein is more labile than alpha 1. In uninduced HL60 cells, alpha 3 membrane protein comprises 30% of the total alpha isoforms, and is less stable than alpha 1, with a protein half-life of only 9 hours. Upon DMSO induction, steady-state alpha 3 protein decreases markedly within 10 hours, whereas alpha 1 protein remains stable. These results show that posttranscriptional changes during induction play a major role in the differential regulation of alpha 1 and alpha 3 isoforms of Na+,K(+)-ATPase; regulation of the latter may be important for early granulocytic differentiation, or for one of the differentiated functions of mature granulocytes.

Cell Differentiation↗

PubMed1992

Macrophage colony-stimulating factor (CSF-1) enhances invasiveness in CSF-1 receptor-positive carcinoma cell lines.

We have identified two lung carcinoma cell lines, A549 and Calu-1, expressing low levels of the macrophage colony-stimulating factor (CSF-1) receptor (CSF-1R), encoded by the c-fms oncogene. The effect of CSF-1 on the invasive potential of these CSF-1R-positive tumor cell lines and on two other CSF-1R-bearing cell lines, the BT-20 breast carcinoma cell line and the CSF-1 growth-dependent murine macrophage cell line BAC1.2F5, was examined using a human amnionic basement membrane invasion model. Culture of A549, Calu-1, and BAC1.2F5 cells with CSF-1 (250 ng/ml) resulted in a maximal 12-, 5-, and 12-fold enhancement of invasion, respectively, compared to control cells cultured in medium alone. Larger concentrations of CSF-1 (750 ng/ml) reduced A549 and Calu-1 invasiveness compared to the effect of the 250-ng/ml dose. Maximal enhancement in invasion of A549 and Calu-1 cells occurred after a 24- and 48-h exposure to CSF-1, respectively. CSF-1 increased invasiveness 6-fold in BT-20 cells induced by glucocorticoids to express high levels of CSF-1R, in comparison to control cells not exposed to glucocorticoids or CSF-1. In contrast, CSF-1 had no effect on invasion in the CSF-1R-negative MCF-7 cell line. Culture of A549 and Calu-1 cells with other cytokines and growth factors including GM-CSF (500 units/ml), IL-3 (1 ng/ml), interferon-gamma (500 units/ml), and tumor necrosis factor (50 units/ml) had no significant effect on invasiveness. Thus, CSF-1 increases invasiveness in CSF-1R-positive tumor cell lines, suggesting a role in enhancing the metastatic potential of tumor cells expressing the CSF-1R.

Adenocarcinoma↗

PubMed1992

NEU protein overexpression in benign, borderline, and malignant ovarian neoplasms.

In situ hybridization (ISH) analysis of 24 benign, borderline, and malignant ovarian tumor specimens revealed NEU transcript expression by epithelial elements in approximately two-thirds of the samples and high-level expression in 3 grade 3 adenocarcinomas. Immunohistochemical staining (IHC) of a total of 86 specimens (including 17 of those studied by ISH) localized NEU antigen expression to epithelial cells in 36 of 86 samples with strong membrane staining observed in 12, including 1 benign, 1 borderline serous carcinoma, 3 clear cell/endometrioid carcinomas, and 7 predominantly papillary serous carcinomas with areas of clear cell/endometrioid histology. Clinical correlation of the IHC results for the 72 Stage I-IV invasively malignant neoplasms revealed no statistically significant association of the intensity of NEU IHC staining with either relapse-free or overall survival. However, more of the patients whose tumors showed strong membrane staining for NEU antigen suffered relapses of disease by 3 and 4 years than did patients whose tumors showed weak or no membrane staining. These results suggest a role for the NEU gene product in the physiology of benign ovarian surface epithelium and the neoplastic epithelium of preinvasive borderline and some invasively malignant adenocarcinomas.

Adenocarcinoma↗

PubMed1992

Neu proto-oncogene amplification and expression in ovarian adenocarcinoma cell lines.

In this communication, the authors summarize their characterization of eight ovarian adenocarcinoma-derived cell lines for level of neu gene amplification, expression of neu transcripts and protein, and intraperitoneal tumorigenicity in nude mice. Two of the eight cell lines in our study (SKOV3 and YAOVBIX1) exhibited five- to ninefold neu DNA sequence amplification, accompanied by up to 200-fold overexpression of transcripts and protein (p185). Both of these cell lines expressed a major approximately 7.5 kb neu-complementary transcript not previously reported in other neu-positive tumor cell lines. One pair of cell lines (YAOVBIX1 and YAOVBIX3), isolated from a single ovarian carcinoma patient's ascites sample differed dramatically in regard to level of neu gene amplification and expression. Immunohistochemical staining of the primary ovarian tumor from which these two lines were derived demonstrated populations of both neu-positive and neu-negative malignant epithelial cells. Seven of the eight ovarian carcinoma lines produced intra-abdominal tumors after intraperitoneal injection into nude mice, irrespective of level of neu gene expression. This study demonstrates tumor cell heterogeneity with regard to neu gene amplification and expression in an ovarian adenocarcinoma, reveals the overexpression of novel neu-complementary transcripts in two independently isolated ovarian adenocarcinoma cell lines, and suggests that neu gene expression is not required for intraperitoneal tumorigenicity of ovarian carcinoma xenografts in a nude mouse model system.

Adenocarcinoma↗

PubMed1991

Adjuvant whole-abdominal radiation therapy in uterine papillary serous carcinoma.

Nine patients from 34 to 74 years of age (median, 67 years of age) with uterine papillary serous carcinoma (UPSC) were treated with whole-abdominal radiation therapy (WART) on an adjuvant basis after cytoreductive surgery. All patients were treated with megavoltage photons to an abdominopelvic field to a median dose of 2500 cGy, with continued treatment to a whole pelvic field to a median dose of 4500 cGy. Three patients received additional boost to the vaginal apex. Follow-up time ranged from 6 to 31 months (median, 25 months) after completion of WART. Six patients had recurrent disease at 5 to 20 months (median, 7.5 months). Four of these patients died of their disease during the follow-up period. Three of six patients in whom treatment failed had disease at the vaginal apex. None of these patients received boost radiation therapy to that site. In contrast, two of three patients remaining disease free were treated with additional vaginal apex irradiation. Based on these results, the authors do not routinely recommend WART for adjuvant treatment of UPSC. They do, however, recommend vaginal apex irradiation for these patients.

Adult↗

PubMed1991

Tumor necrosis factor stimulates epithelial tumor cell motility.

Cellular motility is a critical function in embryonic development, tissue repair, and tumor invasion. We used assays of scattering (epithelial colony dispersion), cell migration, and cell invasion to study cytokine-regulated motility in epithelial and carcinoma cell lines. Tumor necrosis factor (TNF) stimulated motility in 12 of 14 cell lines in one or more assay systems. The motility-stimulating activity of TNF did not correlate with its antiproliferative activity. In lines whose migration was stimulated by both TNF and scatter factor (SF), a fibroblast-derived cytokine which stimulates epithelial cell motility, saturating concentrations of TNF plus SF induced greater migration than either agent alone. Anti-TNF monoclonal antibody blocked TNF- but not SF-stimulated motility. While various other factors (basic fibroblast growth factor, interleukin 6, interleukin 2, colony-stimulating factor 1) had little or not motility-stimulating activity, phorbol-12-myristate-13-acetate (PMA), a tumor-promoting phorbol ester, scattered and/or stimulated migration in all cell lines studied. Combinations of saturating concentrations of TNF plus PMA or of SF plus PMA induced greater migration than did any agent alone. These findings suggest that (a) carcinoma cell motility may be mediated by multiple biochemical pathways and (b) TNF stimulates epithelial motility by a mechanism different from that of SF and PMA. In vivo, TNF might enhance invasiveness of some carcinomas or stimulate epithelial wound healing.

Animals↗

PubMed1991

Molecular biology of ovarian cancer.

This minireview, which due to the limitations of space cannot claim to be exhaustive, summarizes major advances in molecular biologic research on ovarian surface epithelial (adeno)carcinomas communicated approximately between the beginning of April 1990 through the end of March 1991. We focus primarily on studies of oncogenes, peptide hormone growth factors and their receptors, steroid hormone receptors, cytogenetics and flow cytometry, and resistance to therapy with cytotoxic agents.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1991

FMS (CSF-1 receptor) and CSF-1 transcripts and protein are expressed by human breast carcinomas in vivo and in vitro.

The expression in vivo of FMS transcripts and antigen by neoplastic epithelial cells was demonstrated immunohistochemically or by in situ hybridization in sixteen of seventeen human breast carcinoma specimens and one case of sclerosing adenosis. Expression of CSF-1 receptor (FMS) transcripts and protein was also observed in vitro in two or three breast carcinoma-derived cell lines and was dramatically increased by dexamethasone, a potent glucocorticoid and inducer of mammary epithelial cell differentiation. Immunohistochemical staining with an anti-CSF-1 antibody identified neoplastic epithelial cell co-expression of fms and CSF-1 antigens in more than one-third of the fms-positive invasive carcinoma specimens. These results suggest that autocrine and paracrine interactions of the lymphohematopoietic cytokine CSF-1 and its receptor may participate in the biology of human mammary neoplasms.

Blotting, Northern↗

PubMed1990

The cytokine CSF-1 (M-CSF) expressed by endometrial carcinomas in vivo and in vitro, may also be a circulating tumor marker of neoplastic disease activity in endometrial carcinoma patients.

Endometrial epithelial cell expression of CSF-1 and FMS antigens was studied in vivo and in vitro in 24 human endometrial carcinoma and 11 benign endometrial biopsy specimens. Twenty-one of 24 adenocarcinomas and 4 of 11 benign lesions stained positively (by IHC) with rabbit anti-human CSF-1 antibodies, while all 24 carcinomas and 3 out of 11 benign lesions (all secretory endometrial specimens) showed significant IHC staining (1+ or greater) of epithelial elements and tissue macrophages with a mouse anti-FMS (CSF-1 receptor) monoclonal antibody. CSF-1 levels in plasma from endometrial carcinoma patients (85 samples, 24 patients) were also found to be markedly elevated (some greater than 100 ng/ml) in patients with active or recurrent disease. In vitro, several endometrial carcinoma cell lines were shown to express FMS complementary transcripts and FMS antigen which were very similar if not identical to those expressed in choriocarcinoma cell line positive controls. Autocrine and paracrine effects mediated by tumor or stromally produced CSF-1 and a tumor epithelial cell CSF-1 receptor may therefore contribute to the biological behavior of endometrial neoplasms in vivo and in vitro.

Adenocarcinoma↗

PubMed1990

Ovarian adenocarcinomas express fms-complementary transcripts and fms antigen, often with coexpression of CSF-1.

In earlier studies of oncogene expression in ovarian and endometrial neoplasms, the authors reported that high tumor levels of fms-complementary transcripts correlate with high histologic grade and advanced clinical stage presentations. In this communication, they pursue these initial clinicopathologic investigations to demonstrate by in situ hybridization and immunohistochemistry that malignant epithelial cells of 14 of 14 invasive adenocarcinomas of the ovary express fms-complementary transcripts. By Northern blotting and by reverse transcription, followed by polymerase chain reaction amplification, the authors also were able to demonstrate fms transcript expression in several ovarian and endometrial carcinoma-derived cell lines. Because about half (6/14) of the invasive adenocarcinoma specimens were shown to coexpress fms and colony-stimulating factor 1, the authors propose that the expression of this lymphohematopoietic cytokine and its receptor by ovarian adenocarcinomas could contribute to their proliferative and invasive characteristics in vivo.

Adenocarcinoma↗

PubMed1989

Human IgG Fc receptor (hFcRII; CD32) exists as multiple isoforms in macrophages, lymphocytes and IgG-transporting placental epithelium.

We previously isolated cDNA clones from a human monocyte library that encoded one member of a family of low-affinity surface receptors for the Fc domain of IgG (hFcRII-A). To investigate possible structural and functional heterogeneity among these receptors, we have now isolated two additional cDNAs (hFcRII-B and hFcRII-C) from a human placental library, placenta being a good source of FcR-bearing macrophages and epithelial cells. Three cDNAs encoded related but distinct transmembrane glycoproteins containing two immunoglobulin-like domains; however, transfected cells produced receptors that were indistinguishable on the basis of ligand binding or reactivity with anti-hFcRII monoclonal antibodies. The sequences of hFcRII-A and -B were most closely related and were identical except for several amino acid substitutions and one small internal deletion. While the ectodomain of hFcRII-C was identical to hFcRII-B, its cytoplasmic tail was unrelated but highly homologous to the corresponding domain of the receptor isoform (mFcRII-B2) found in murine macrophages. Thus, human FcRII may be derived from at least two alternatively spliced genes. Northern blots revealed little difference in the pattern of expression of hFcRII isoforms among various myeloid and lymphoid cells or cell lines. However, the blots--as well as in situ hybridization and immunohistochemistry--demonstrated that hFcRII-C (along with a second monocyte marker, the c-fms encoded CSF-1 receptor) was expressed in placental syncytiotrophoblasts. Since syncytiotrophoblasts comprise the IgG-transporting epithelium of the placental villus, these findings suggest that FcR found in the immune system and in certain epithelia may be structurally or functionally related.

Amino Acid Sequence↗

PubMed1989

Enhancement of anthracycline growth inhibition in parent and multidrug-resistant Chinese hamster ovary cells by cyclosporin A and its analogues.

Cyclosporins have been shown to sensitize multidrug-resistant cells to chemotherapeutic agents but, generally, have minimal effect on sensitive lines. We studied the effect of cyclosporin A (CsA) and two nonimmunosuppressive analogues, 11-methyl-leucine- (11-Me-Leu-CsA) and 6-methyl-alanine-cyclosporin A (6-Me-Ala-CsA), on the action of doxorubicin (DOX) and 4'-epidoxorubicin against parent (AuXB1) and multidrug-resistant (CHRC5) Chinese hamster ovary cells. CsA and its two analogues reduced the IC50 values for DOX in sensitive AuXB1 cells from 0.1 to 0.01-0.02 microM. Cyclosporins reduced the IC50 of DOX in resistant CHRC5 cells from 9 to 0.1 (CsA), 0.7 (6-Me-Ala-CsA), and 1.2 microM (11-Me-Leu-CsA). Similar results were seen when cyclosporins were combined with 4'-epidoxorubicin. The cyclosporins alone had no effect at these concentrations (1-2.0 micrograms/ml). Dose-response curves suggested that CsA was a more potent modifying agent than 11-Me-Leu-CsA towards resistant CHRC5 cells. The ability of the cyclosporins to enhance anthracycline growth inhibition in parent AuXB1 cells may be related to an increase in drug uptake and an increase in anthracycline-induced DNA damage. CsA increased DOX accumulation as well as DOX-associated DNA single-strand breaks in AuXB1 cells over those seen in cells exposed to DOX alone. The degree of increase in DNA breaks paralleled the degree of growth inhibition seen in cells exposed to the same concentrations of drugs. In contrast, CsA had no effect on DOX accumulation or DNA single-strand breaks in CHRC5 cells. These findings imply that, in the resistant cell line, the enhanced anthracycline growth inhibition in the presence of CsA is independent of DOX accumulation and single-strand DNA breaks. These studies demonstrate that CsA and two nonimmunosuppressive analogues can sensitize both sensitive and resistant Chinese hamster ovary cells to anthracyclines. Furthermore, the mechanisms underlying this effect may differ between sensitive and multidrug-resistant cells.

Animals↗

PubMed1989

Smooth muscle releases an epithelial cell scatter factor which binds to heparin.

We report that cultured bovine calf aorta and human adult iliac artery smooth muscle cells release a soluble factor which causes spreading and separation of cells in normally tight, cohesive epithelial colonies, similar to the morphologic changes induced by the fibroblast-derived scatter factor (SF). Smooth muscle-derived SF was heat sensitive, trypsin labile, and nondialyzable, consistent with a protein (or proteins). Its effects on epithelium were not mimicked by a variety of proteolytic enzymes, growth factors, or hormones, and were not blocked by antiproteases or by antibodies to fibronectin and basic fibroblast growth factor. Epithelial cell proliferation was unaffected or only mildly stimulated by partially purified SF at concentrations that produced cell scattering. Both smooth muscle- and MRC5 human embryo fibroblast-derived SFs could be partially purified with similar elution patterns on a number of different chromatographic columns, including DEAE-agarose, heparin-sepharose, Bio-Rex 70, concanavalin A-sepharose, and MonoQ. SF from both sources bound tightly to heparin-sepharose, requiring 1.3 to 1.4 M NaCl for elution. The morphologically obvious cell scattering effect was markedly inhibited by soluble heparin at concentrations down to 5 micrograms/ml, and this inhibition was prevented by protamine. These data suggest that vascular smooth muscle cells produce an epithelial cell scattering factor with properties similar to the fibroblast-produced factor, including a high affinity for heparin. Such factors are potentially important because they may represent a new class of proteins that primarily regulate cell mobility rather than growth and differentiation.

Animals↗