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Biomedical subjects

R C Bast

Publications and source records attributed to R C Bast.

At least 127 records · Page 7Linked to original sources
PubMed1993

Constitutive production of macrophage colony-stimulating factor and interleukin-6 by human ovarian surface epithelial cells.

Normal and neoplastic epithelial cells produce growth factors that can affect cells from different lineages. Epithelial ovarian cancers produce M-CSF and IL-6. In the present study, production of these cytokines has been measured in the apparently normal epithelial cells from which epithelial ovarian neoplasms are thought to arise. Epithelial cells from the surface of premenopausal human ovaries were established in short-term cultures. The cells bound anti-cytokeratin antibodies and exhibited characteristic epithelial morphology by light and transmission electron microscopy. M-CSF and IL-6 were detected in supernatants from cultures of these cells, using assays specific for each factor. Cytokine levels were comparable to those in supernatants from ovarian and breast cancer cell lines. M-CSF expression could also be demonstrated by immunohistochemical analysis with specific rabbit heteroantiserum. Thus, M-CSF and IL-6 are produced constitutively by normal as well as by neoplastic ovarian epithelium.

Cells, Cultured↗
PubMed1993

Mutation of the p53 tumor-suppressor gene is not a feature of endometrial hyperplasias.

OBJECTIVE: Mutation and overexpression of the p53 gene occur in approximately 20% of endometrial carcinomas. To determine whether alteration of the p53 gene is an early event in endometrial carcinogenesis, we examined the p53 gene in endometrial hyperplasias. STUDY DESIGN: Genomic deoxyribonucleic acid was extracted from 117 endometrial hyperplasias (36 simple, 40 complex, 41 atypical) and 30 endometrial cancers. Exons 5 through 8 of the p53 gene were amplified by means of the polymerase chain reaction. Mutations in the p53 gene were sought with single-stranded conformation polymorphism analysis and confirmed by direct deoxyribonucleic acid sequencing. RESULTS: None of 117 endometrial hyperplasias were found to have mutations in the p53 gene, whereas mutations were seen in three of 30 (10%) endometrial cancers (p < 0.02). The p53 mutations seen in three cancers were confirmed by direct sequencing (codons 157, 180, 272). CONCLUSION: Because it does not appear to be a feature of endometrial hyperplasias, mutation of the p53 gene may represent a relatively late event in endometrial carcinogenesis.

Base Sequence↗
PubMed1993

The effect of antibodies and immunotoxins reactive with HER-2/neu on growth of ovarian and breast cancer cell lines.

OBJECTIVE: Because HER-2/neu is overexpressed in one third of breast and ovarian cancers, we examined the effect of unconjugated monoclonal antibodies (ID-5, PB-3, TA-1) and an immunotoxin (TA-1-ricin) reactive with this protooncogene on the growth of breast and ovarian cancer cell lines. STUDY DESIGN: The tritiated thymidine incorporation assay was used to examine the effect of unconjugated antibodies on proliferation. A limiting dilution clonogenic assay was used to assess the effect of immunotoxin on cellular cytotoxicity. RESULTS: Scatchard analysis revealed that OVCA 420, OVCA 429, OVCA 432, and OVCA 433 cells had approximately 10(4) HER-2/neu receptors per cell, whereas the SKOv3 and SKBr3 cell lines expressed 10(5) and 10(6) receptors per cell, respectively. Monoclonal antibody ID-5 caused significant inhibition of tritiated thymidine incorporation in SKBr3, SKOv3, and OVCA 420 cells (p < 0.002). The TA-1-rich immunotoxin significantly inhibited the clonogenic growth of only SKBr3 and SKOv3 cells. CONCLUSION: HER-2/neu may be a useful target for immunotherapy with unconjugated antibodies and immunotoxins in ovarian and breast cancers that overexpress this protooncogene.

Antibodies, Monoclonal↗
PubMed1993

Determination of proliferation index in advanced ovarian cancer using quantitative image analysis.

It has been shown that the monoclonal antibody Ki-67 reacts with a nuclear antigen that is expressed only by proliferating cells. The feasibility of using image analysis to quantitate Ki-67 staining (proliferation index [PI]) of epithelial ovarian cancers was investigated. The PI was determined in 50 advanced-stage primary ovarian cancers. Frozen sections were immunostained with the Ki-67 monoclonal antibody, and the PI was calculated using static image analysis. Among 35 stage III ovarian carcinomas, the median PI was 8.9%, compared with 17.7% in 15 stage IV cancers (P = 0.06). There was no relationship between PI and histologic grade. The median survival time of 32 patients whose cancers had a high Ki-67 expression (> or = 7.5%) was 16.8 months, which differed significantly (P < 0.01) from the median survival of 31.5 months observed in patients whose tumors demonstrated low Ki-67 expression (< 7.5%). Quantitative image analysis of Ki-67-stained fresh-frozen ovarian cancers may provide useful prognostic information. Further studies are warranted to investigate the relationship between Ki-67 expression and other known clinicopathologic and genetic features of ovarian cancer.

Antibodies, Monoclonal↗
PubMed1993

The biology of ovarian cancer.

Recent studies have begun to elucidate the molecular events involved in the development of ovarian cancer. First, it has been shown that epithelial ovarian cells both produce and have receptors for many peptide growth factors. It is possible that these growth factors may participate in autocrine and paracrine growth-regulatory pathways in these cells. Increased activity of stimulatory factors, eg, transforming growth factor-alpha, or decreased activity of inhibitor factors, eg, transforming growth factor-beta, may facilitate malignant transformation. In addition, it has been shown that ovarian cancer cells often have acquired the ability to degrade extracellular matrix and invade the underlying tissues. Finally, alterations in several oncogenes and tumor-suppressor genes, including HER2/neu, c-myc, and p53, have been found in ovarian cancers. Although exciting insights into the molecular pathology of ovarian cancer have been gained, we remain far from a comprehensive understanding of the biology of this highly lethal disease.

Female↗
PubMed1993

Differential diagnosis of ovarian cancer with tumour markers CA 125, CA 15-3 and TAG 72.3.

OBJECTIVE: To determine the accuracy of tumour associated antigens CA 125, CA 15-3 and TAG 72.3 in the differential diagnosis of benign and malignant pelvic masses and to compare the results with a previously defined risk of malignancy index (RMI). DESIGN: Retrospective analysis of samples collected during a prospective observational study. SETTING: Department of Obstetrics and Gynaecology, the Royal London Hospital and Duke University Medical Center. SUBJECTS: One hundred and forty-three consecutive patients undergoing surgery for an adnexal mass. METHOD: Tumour marker levels were determined by radio-immunoassay in stored serum samples obtained from 143 study subjects. RESULTS: The highest diagnostic accuracy of the tumour marker panel was achieved by defining a positive result as elevation of any two of CA 125 (> 30 u/ml), CA 15-3 (> 30 u/ml) and TAG 72.3 (> 10 u/ml), (sensitivity 66.7%, specificity 93.1%). Similar diagnostic accuracy could be achieved by CA 125 alone using an upper limit of 50 u/ml (sensitivity 66.7%, specificity 94.1%). Inclusion of CA 15-3 or TAG 72.3 in stepwise logistic regression analysis did not improve the discriminative performance of the RMI. CONCLUSION: The risk of malignancy index incorporating CA 125, menopausal status and ultrasound is superior to the panel of three tumour markers for pre-operative differential diagnosis of the pelvic mass.

Antigens, Neoplasm↗
PubMed1993

Alkylating agents and immunotoxins exert synergistic cytotoxic activity against ovarian cancer cells. Mechanism of action.

Alkylating agents can be administered in high dosage to patients with ovarian cancer using autologous bone marrow support, but drug-resistant tumor cells can still persist. Immunotoxins provide reagents that might eliminate drug resistant cells. In the present study, concurrent treatment with alkylators and immunotoxins proved superior to treatment with each agent alone. Toxin immunoconjugates prepared from different monoclonal antibodies and recombinant ricin A chain (rRTA) inhibited clonogenic growth of ovarian cancer cell lines in limiting dilution assays. When alkylating agents and toxin conjugates were used in combination, the addition of the immunotoxins to cisplatin, or to cisplatin and thiotepa, produced synergistic cytotoxic activity against the OVCA 432 and OVCAR III cell lines. Studies performed to clarify the mechanism of action showed that cisplatin and thiotepa had no influence on internalization and binding of the 317G5-rRTA immunotoxin. Intracellular uptake of [195m]Pt-cisplatin was not affected by the immunoconjugate and thiotepa. The combination of the 317G5-rRTA and thiotepa, as well as 317G5-rRTA alone, increased [195m]Pt cisplatin-DNA adduct levels. The immunotoxin alone and in combination with the alkylators decreased intracellular glutathione levels and reduced glutathione-S-transferase activity. Repair of DNA damage induced by the combination of alkylators and 317G5-rRTA was significantly reduced when compared to repair after damage with alkylators alone. These findings suggest that immunotoxins affect levels and activity of enzymes required for the prevention and repair of alkylator damage.

Antibodies, Monoclonal↗
PubMed1993

High-dose chemotherapy and autologous bone marrow support as consolidation after standard-dose adjuvant therapy for high-risk primary breast cancer.

PURPOSE: We studied high-dose cyclophosphamide, cisplatin, and carmustine (CPA/cDDP/BCNU) with autologous bone marrow support (ABMS) as consolidation after standard-dose adjuvant chemotherapy treatment of primary breast cancer involving 10 or more axillary lymph nodes. PATIENTS AND METHODS: One hundred two women with stage IIA, IIB, IIIA, or IIIB breast cancer involving 10 or more lymph nodes at surgery were registered; 85 were eligible, treated, and assessable. Patients were treated with four cycles of standard-dose cyclophosphamide, doxorubicin, and fluorouracil (CAF), followed by high-dose CPA/cDDP/BCNU with ABMS. RESULTS: Actuarial event-free survival for the study patients at a median follow-up of 2.5 years is 72% (95% confidence interval, 56% to 82%). Comparison to three historical or concurrent Cancer and Leukemia Group B (CALGB) adjuvant chemotherapy trials selected for similar patients showed event-free survival at 2.5 years to be between 38% and 52%. Therapy-related mortality was 12%; pulmonary toxicity of variable severity occurred in 31% of patients. Quality-of-life evaluations indicate that patients are functioning well without major impairments. CONCLUSION: High-dose consolidation with CPA/cDDP/BCNU and ABMS after standard-dose CAF results in a decreased frequency of relapse in patients with high-risk primary breast cancer compared with historical series at the median follow-up of 2.5 years. Evaluation in a prospective, randomized trial is warranted and currently underway.

Adult↗
PubMed1993

Perspectives on the future of cancer markers.

More fundamental understanding of cell growth regulation will provide novel approaches for detecting, preventing, and treating different cancers. Activation of protooncogenes or loss of tumor-suppressor genes can have both prognostic and therapeutic importance. In epithelial ovarian cancer, poor prognosis is associated with continued expression or overexpression of tyrosine kinase growth factor receptors p170EGFR, p165fms, and p185erbB-2. Over-expression of erbB-2 (HER-2/neu) by breast and ovarian cancers already permits effective targeting of antibodies and immunotoxins. Ultimately, molecular analysis of individual cancers will guide the application of specific therapies to inhibit activated oncogenes or restore the function of tumor-suppressor genes. Circulating growth factors, oncogene products, and tumor-associated antigens may provide markers for earlier detection of some cancers. In epithelial ovarian cancer, concentrations of CA 125 can be increased 1-5 years before clinical diagnosis, and approximately 50% of patients with stage I disease have had an abnormal CA 125 concentration. Combining CA 125 with two novel markers--OVX1 and M-CSF--has retrospectively detected > 98% of stage I ovarian cancers. Although the specificity of the three markers is insufficient for cost-effective screening, serum tests for them could prompt the performance of transvaginal sonography, substantially decreasing the number of sonograms required. Genetic markers in the germ line of patients at increased risk for certain cancers will almost certainly influence strategies for prevention or detection. In familial breast, and ovarian cancer, a locus on chromosome 17q tracks risk of cancer in a fraction of kindreds. How often germline abnormalities will be detected in patients with apparently sporadic cancer remains to be determined.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1993

Mutation and overexpression of p53 in early-stage epithelial ovarian cancer.

OBJECTIVE: To investigate whether mutation and overexpression of p53 is a feature of early-stage ovarian cancers. METHODS: Because early-stage ovarian cancers are relatively uncommon, we adapted p53 immunostaining and DNA sequencing methods for use in paraffin-embedded tissue blocks. Early-stage ovarian cancers from 52 patients treated at Duke University between 1980-1991 were analyzed. RESULTS: Immunostaining for p53 consistent with overexpression was seen in 29% of early-stage (I/II) ovarian cancers overall. The incidence of p53 overexpression was lower in cancers confined to the ovaries (stage IA/IB) (15%) than in cancers that had spread outside the ovaries (stage IC/II) (44%) (P = .03). Although p53 overexpression was seen more frequently in large tumors (diameter greater than 10 cm) and in tumors with "high-risk" features (stage IC or II, or grade 3), these relationships were not statistically significant. Recurrent disease developed in 35% of the patients in this series, but there was no relationship between p53 overexpression and recurrence rate or survival. The presence of point mutations in the p53 gene was confirmed by DNA sequencing in eight cancers that overexpressed p53. CONCLUSION: Mutation and overexpression of p53 are less frequent in early-stage ovarian cancers than in advanced-stage cases. P53 overexpression is not associated with adverse outcome in early-stage ovarian cancer.

DNA, Neoplasm↗
PubMed1992

Clonal origin of epithelial ovarian carcinoma: analysis by loss of heterozygosity, p53 mutation, and X-chromosome inactivation.

BACKGROUND: It has been suggested that multiple sites of epithelial ovarian carcinoma on the peritoneal surface reflect polyclonal disease arising from multiple primary tumors in the peritoneal mesothelium, rather than monoclonal disease spread by metastases from one primary ovarian cancer. PURPOSE: The purpose of this study was to investigate whether ovarian cancer has a monoclonal or polyclonal origin. METHODS: DNA specimens were obtained from peripheral blood lymphocytes (normal DNA) and from multiple tumor deposits of 17 women with epithelial ovarian carcinoma: primary tumors, metastatic deposits, and ascites. The clonal origin of each tumor was determined by performing (a) analysis to detect loss of heterozygosity at five loci on chromosomes 5, 11, 13, and 17; (b) sequencing of exons 5-8 of the p53 gene; and (c) X-chromosome inactivation analysis of the phosphoglycerate kinase (PGK) gene. RESULTS: In 15 of the 17 cases analyzed, there was clear evidence of monoclonal origin. The probability that the genetic events documented in these 15 cases occurred as independent events in each tumor deposit ranged from 2.5 x 10(-1) to 3.7 x 10(-16). In two cases, the pattern of allelic deletion and p53 gene mutation was compatible with either a monoclonal origin or origin from two primary ovarian tumors. CONCLUSIONS: The results did not support the hypothesis that ovarian cancer is a multifocal, polyclonal disease. Instead, the data suggest that sporadic epithelial ovarian carcinoma has either a monoclonal or a dual primary origin. IMPLICATIONS: These findings have important implications for understanding of the natural history of ovarian cancer and for clinical strategies aimed at prevention and early detection. Further studies will be required to determine the clonal origin of familial hereditary ovarian cancer.

Alleles↗
PubMed1992

Fibronectin is an immunosuppressive substance associated with epithelial ovarian cancer.

BACKGROUND: Although the ascites of patients with ovarian cancer has been reported to contain immunosuppressive factors, the identity and source of this activity has not been determined. Previously, the authors showed that conditioned media from two of four epithelial ovarian cancer cell lines inhibits proliferation of mitogen-stimulated human lymphocytes. The physical characteristics of the inhibitory substance are unlike those of peptide growth factors but closely resemble those of fibronectin. METHODS AND RESULTS: In the current study, it was found that the two ovarian cancer cell lines that produce the inhibitory substance have more fibronectin on the cell surface and secrete significantly more immunoreactive fibronectin into their culture media than the other two ovarian cancer cell lines. In addition, the immunosuppressive activity was bound to a gelatin-Sepharose affinity column, known to bind fibronectin. Finally, in ascites from 20 patients with advanced epithelial ovarian cancer, fibronectin levels correlated with the ability to inhibit proliferation of lectin-stimulated lymphocytes (P < 0.001). CONCLUSIONS: Fibronectin is produced by some ovarian cancer cell lines and acts to inhibit proliferation of mitogen-stimulated lymphocytes. Additional studies are needed to clarify the role of fibronectin in ovarian cancer.

Ascites↗
PubMed1992

Detection of a novel marker in the bronchial secretions of patients with non-small cell lung cancer using the 4B5 monoclonal antibody.

A murine monoclonal antibody designated 4B5 was raised against the high molecular weight fraction of pooled sputum from patients with non-small cell lung cancer (NSCLC). Immunohistochemical staining indicated that 4B5 binds to histologically normal bronchial epithelium distant from tumor in 72% (39 of 54) of patients with NSCLC, but it binds to the primary cancer in only 13% (7 of 54) of the same patients. The antibody reacted less intensely with the bronchial epithelium in 16.6% (3 of 18) of autopsied patients without significant lung disease. The antigen recognized by 4B5 is a high molecular weight glycoprotein of more than 400 kilodaltons, judged by gel filtration and sodium dodecyl sulfate-polyacrylamide gel electrophoresis and western blot analysis. Antigenic activity persisted after heating and resisted treatment with neuraminidase, but it was destroyed using protease and periodate. Multiple epitopes were present on each molecule recognized by 4B5. The determinants recognized by this antibody deserve additional study as possible markers of premalignant change in patients with NSCLC.

Antibodies, Monoclonal↗
PubMed1992

Overexpression and mutation of p53 in endometrial carcinoma.

Immunohistochemical staining for the p53 protein was performed in 107 snap frozen primary endometrial adenocarcinomas and 15 benign uterine tissues using monoclonal antibody PAb1801. No staining was seen in benign samples, whereas intense nuclear staining of cancer cells consistent with overexpression of the p53 protein was observed in 22 of 107 cancers (21%). p53 overexpression was more frequent in advanced (Stage III/IV) cancers (41%) than in early (Stage I/II) cancers (9%) (P less than 0.001), and also was associated with nonendometrioid histology (P = 0.008), positive peritoneal cytology (P = 0.01), extrauterine metastases (P = 0.003), and negative progesterone receptor status (P = 0.04). To confirm the relationship between p53 overexpression and mutation, p53 mRNA from 8 cancers was reverse transcribed and amplified using the polymerase chain reaction. DNA sequencing revealed point mutations in each of the 5 cancers that overexpressed p53, whereas the wild-type sequence was found in 3 cancers that did not overexpress the protein. Each of the 5 mutations resulted in an amino acid substitution in a highly conserved region of the p53 gene where mutations have been found in other cancers. Further studies are warranted to determine whether the association between p53 overexpression and advanced stage disease is due to accumulation of genetic lesions during tumor progression or whether p53 alterations confer a more virulent phenotype.

Adenocarcinoma↗
PubMed1992

Stimulation of ovarian tumor cell proliferation with monocyte products including interleukin-1, interleukin-6, and tumor necrosis factor-alpha.

OBJECTIVE: We investigated whether monocyte-derived factors could stimulate the growth of ovarian cancer cells. STUDY DESIGN: Human peripheral blood monocytes or human monocyte-like cell lines THP-1 and U-937 were cultured with or without macrophage colony-stimulating factor, lipopolysaccharide, or phorbol myristate acetate. Culture supernatants or recombinant cytokines were assayed for growth stimulation of ovarian cancer cell lines by tritium-thymidine incorporation and direct cell counts followed by statistical analysis with Student t test. RESULTS: Conditioned medium from peripheral blood monocytes or from THP-1 or U-937 cells stimulated ovarian cancer cell growth. Interleukin-1 alpha, tumor necrosis factor-alpha, and interleukin-6 also stimulated ovarian cancer cell growth, whereas macrophage, granulocyte, and granulocyte-macrophage colony-stimulating factor did not. Concentrations of tumor necrosis factor, interleukin-1, and interleukin-6 in conditioned medium could not account for all the growth stimulation, and activity remained after neutralization of tumor necrosis factor, interleukin-1, and interleukin-6 with antibodies. CONCLUSIONS: Interleukin-1, interleukin-6, tumor necrosis factor, and additional monocyte factor(s) could provide paracrine growth stimulation when monocytes are attracted to ovarian cancers that produce macrophage colony-stimulating factor.

Cell Division↗
PubMed1992

Regulation of growth of normal ovarian epithelial cells and ovarian cancer cell lines by transforming growth factor-beta.

OBJECTIVE: The purpose of this study was to study the role of transforming growth factor-beta in regulation of proliferation of normal and malignant ovarian epithelial cells. STUDY DESIGN: We examined production of and responsiveness to transforming growth factor-beta in primary monolayer cultures of epithelial cells from five normal human ovaries and in five ovarian cancer cell lines. RESULTS: In normal ovarian epithelial cells, proliferation always was inhibited by transforming growth factor-beta (greater than 40%) (p less than 0.01). Among the cancer cell lines, proliferation of one was markedly inhibited (greater than 95%) (p less than 0.01), two were only modestly inhibited (15% to 20%) (p less than 0.05), and two were unaffected. In addition, we found that all of the normal ovarian epithelial cells and four of five ovarian cancer cell lines produce transforming growth factor-beta ribonucleic acid and protein. CONCLUSIONS: These data suggest that transforming growth factor-beta may act as an autocrine growth inhibitory factor for normal ovarian epithelium in vivo. Because most of the ovarian cancer cell lines are relatively resistant to the growth inhibitory effect of transforming growth factor-beta and because one cell line does not produce transforming growth factor-beta, it is possible that loss of the transforming growth factor-beta pathway may play a role in the development of some ovarian cancers.

Cell Division↗
PubMed1992

The effect of interferon gamma on epidermal growth factor receptor expression in normal and malignant ovarian epithelial cells.

OBJECTIVE: We examined the effect of interferon gamma on proliferation and epidermal growth factor receptor expression in ovarian cancer cell lines and normal ovarian epithelial cells. STUDY DESIGN: The tritiated thymidine incorporation assay was used to assess the effect of interferon gamma on proliferation. Scatchard analysis of anti-epidermal growth factor receptor antibody binding, and Western blotting of immunoprecipitates was used to assess the effect of interferon gamma on epidermal growth factor receptor expression. RESULTS: Although interferon gamma elicited 30% to 40% decreases in proliferation, epidermal growth factor receptor expression was strikingly increased in all four ovarian cancer cell lines. Scatchard analysis indicated that this increase occurred primarily at the cell surface, but total cellular receptor levels also were increased. In contrast, interferon gamma treatment of normal ovarian epithelial cells affected neither proliferation nor epidermal growth factor receptor levels. CONCLUSION: Because the up-regulation of epidermal growth factor receptors by interferon gamma appears to be confined to malignant cells, interferon gamma may facilitate immunotherapy and imaging of ovarian cancers by means of immunoconjugates directed against the epidermal growth factor receptor.

Antibodies, Monoclonal↗