Molecular genetic markers in familial adenomatous polyposis.
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Adenomatous Polyposis Coli↗
Biomedical subjects
B M Boman
Publications and source records attributed to B M Boman.
Cellular growth response to epidermal growth factor in colon carcinoma cells with an amplified epidermal growth factor receptor derived from a familial adenomatous polyposis patient.
The receptor binding and cellular growth responses to exogenous epidermal growth factor (EGF) were studied using the DiFi cell line established from a familial adenomatous polyposis patient. The number of cell membrane EGF receptors on DiFi cells, as measured by competitive radioligand binding assays and Scatchard analysis of 125I-EGF binding isotherms, was calculated to be 4.8 x 10(6) receptors/cell. An acid prewash step performed prior to ligand binding assays did not reveal additional receptor numbers. A single, low-affinity receptor population was identified by Scatchard analysis, with an apparent Kd of 4.6 nM. This result was confirmed by radioligand binding studies performed in the presence and absence of the receptor-antagonist monoclonal antibody 528 IgG that binds predominantly to the low-affinity form of the EGF receptor. DiFi cells at 50-60% confluence, when exposed to 50 nM exogenous EGF, exhibited a rapid but partial (30%) reduction in their cell membrane-associated receptor, characteristic of sequestration. Exposure of DiFi cells to 50 nM EGF for longer periods of time (4 h) did not result in any further reduction in EGF-receptor number. The cellular growth response of DiFi cells to exogenous EGF was studied in monolayer cultures as well as in a soft agarose assay. Inhibition of soft agar colony formation was observed at exogenous EGF concentrations greater than 1.7 nM, and inhibition of monolayer growth occurred at EGF concentrations greater than 1 nM. In immune complex kinase assays, the DiFi receptor showed similar specific activity to that from the well-characterized A431 cell line. Additionally, phosphorylation of the receptor on tyrosine was qualitatively similar to that of A431 cells, further suggesting that the DiFi receptors identified by EGF-binding studies were biologically functional.
Adenomatous Polyposis Coli↗
Extrachromosomal amplification of the epidermal growth factor receptor gene in a human colon carcinoma cell line.
In situ hybridization, using a biotinylated cDNA probe for the epidermal growth factor receptor (EGFR) gene, indicates that the amplified EGFR genes in the colon tumor cell line, DiFi, are localized in many small double minute chromosomes (dmin) of varying size and visibility. Analysis of the electrophoretic mobility of gamma-irradiated DNA from DiFi by pulsed-field gel electrophoresis and Southern blot hybridization using EGFR probe, indicates that the amplified EGFR in DiFi exists in extrachromosomal, covalently closed circular episomes, presumably equivalent to dmin. Two major and one minor species were observed which had estimated sizes of 650, 1,300, and 2,000 kb, respectively. The DiFi cell line appears to represent a unique case of extrachromosomal EGFR gene amplification in human cells.
Blotting, Southern↗
Application of positron emission tomography to neurological oncology.
PET has a promising role in neuroradiology for accurate diagnosis and prognostication of malignant tumors as well as differential diagnosis of radiation necrosis and recurrent tumors. Particularly, PET has proven its ability to accurately differentiate radiation necrosis from recurrent brain tumor. Active tumors have accelerated glycolysis, and a remarkable accumulation of FDG radiotracer in high grade brain tumors is evident on PET images. Tumor metabolism also proportionally increases with increasing pathologic grades of brain tumor, and accelerated tumor metabolism indicates a poor prognosis for the tumor.
Adult↗
Increased expression of the retinoblastoma gene in human colorectal carcinomas relative to normal colonic mucosa.
We report the first evidence of increased levels of the retinoblastoma (Rb) message in a majority of colorectal cancers when compared with normal mucosa. Southern blot analysis showed an increase in Rb gene copy number in at least 28% of colorectal carcinomas relative to normal mucosa. These results plus previous reports of nonrandom chromosome 13 gains in approximately 50% of colorectal cancers suggest that an increase in Rb gene copy number occurs frequently in these tumors. Possible mechanisms pertaining to overexpression of the Rb gene are discussed in relation to its role as a recessive cancer gene.
Blotting, Northern↗
Specific expression of proteins and phosphoproteins in 3T3 T mesenchymal stem cells at distinct growth arrest and differentiation states.
Murine mesenchymal stem cells can be induced to arrest their growth at a series of growth and differentiation states in the G1 phase of the cell cycle. These include the predifferentiation arrest state (GD) at which the integrated control of proliferation and differentiation is mediated, the growth factor/serum deficiency arrest state (GS), and the nutrient deficiency arrest state (GN). Cells at states of reversible nonterminal differentiation (GD') and irreversible terminal differentiation (TD) can also be isolated. In this paper we have employed 1- and 2-dimensional (D) gel electrophoresis to evaluate changes in specific proteins that occur during the various growth and differentiation states of 3T3 T mesenchymal stem cells. The protein composition of membrane, microsome and cytosol preparations of cells arrested at GD, GS and GN states was determined by 2-D gel electrophoresis. More than 50 distinct polypeptides could be identified for each arrest state in gels analysed by a silver staining procedure or by autoradiography following [35S]-methionine labelling. A second series of studies established that a more limited number of differences could be identified if phosphoproteins were analysed by 1-D gel electrophoresis in cells at the GS, GD, GD' and TD states. These results established that one distinct 37 kD phosphoprotein is present in all growth arrested cells and that two distinct differentiation-associated phosphoproteins with molecular weights of 29 kD and 72 kD are present in cells at the GD' and TD states. Thus, the composition of proteins and phosphoproteins in mesenchymal stem cells serves to characterize different states of growth arrest and differentiation.2+he identification of differential
Animals↗
A phase II study of trimetrexate therapy for metastatic colorectal carcinoma.
Thirty patients with measurable metastatic colorectal carcinoma who had not received prior systemic therapy for advanced disease were treated with trimetrexate, a methotrexate analog. Trimetrexate was administered at a median daily dose of 15 mg/m2 (range, 6-22 mg/m2) intravenously for five days every three weeks. No patient achieved a complete or partial response, although minor responses of brief duration occurred in eight patients. The drug was generally well tolerated, thus permitting frequent dose escalations. Common toxic effects included mucositis, dermatitis, and myelosuppression. Our data suggest that trimetrexate given at these doses and in this schedule is not active against colorectal carcinoma.
Adult↗
Primary lymphoma of bone.
Primary lymphoma of bone is a rare clinical entity that accounts for less than one per cent of all non-Hodgkin's lymphomas. Although they occasionally present as a solitary lesion in bone, lymphoma involving bone is a manifestation of disseminated disease in many instances. All patients initially found to have a solitary lymphoma of bone need to be thoroughly investigated for systemic disease because more than half of the patients presenting with initially solitary bone lesions are found to have systemic disease involving lymph nodes and/or other organs. Choice of therapeutic management is based on the stage of disease. Stage I-E primary lymphoma of bone can be controlled in 70-90% of cases using local radiation therapy alone if adequate radiation doses are used. Patients with advanced disease should be treated with combination chemotherapy in addition to local radiotherapy. Loeffler et al reported long-term survival results of 90% 8-year actuarial overall survival rate for children with primary lymphoma of bone who received combined therapy with radiation and chemotherapy (adriamycin, prednisone and oncovin). The actuarial lymphoma-free survival rate was 100% at eight years. Regardless of stage of the disease, radiation treatment to the primary tumor appears to be critical for adequate local control of disease as well as rapid symptomatic relief.
Adult↗
Adenocarcinoma of the small bowel in lynch syndrome II.
Adenocarcinoma of the small bowel is rare and accounts for about 1% of all gastrointestinal tract cancer. This disorder has been identified in association with Crohn's disease, celiac disease, Peutz-Jegher's syndrome, and familial adenomatous polyposis. We report adenocarcinoma of the small bowel in nine patients from eight Lynch syndrome II extended pedigrees. Each affected patient was in the direct genetic lineage or manifested multiple primary cancers (stomach, colon, endometrium, and ovary) consonant with the tumor spectrum of Lynch syndrome II. The average age of onset for small bowel cancer was 47 years (range 31 to 56 years), versus the general population peak occurrence after the sixth decade. We conclude that small bowel cancer may be an integral component of the tumor spectrum of Lynch syndrome II.
Adenocarcinoma↗
Phase II study of adriamycin with sequential methotrexate and 5-fluorouracil (AMF) in gastric carcinoma.
The purpose of this study was to evaluate the response rate, methotrexate plasma levels, and toxicity of a three-drug regimen in patients with gastric carcinoma. A total of 37 patients with advanced measurable adenocarcinoma of the stomach were treated with Adriamycin, methotrexate, and 5-fluorouracil (AMF). Adriamycin and methotrexate were given as i.v. infusions on day 1; 24 h following methotrexate administration, patients received an i.v. infusion of 5-fluorouracil concomitantly with oral leukovorin factor (given over 48 h). Methotrexate levels were monitored regularly in all patients, and courses were repeated every 3 weeks. The median dose levels per course were 50 mg/m2 (range, 40-60 mg/m2) for Adriamycin, 1,000 mg/m2 (range, 650-1,250 mg/m2) for 5-fluorouracil, and 500 mg/m2 (range, 160-625 mg/m2) for methotrexate. Of 36 evaluable patients, 8 (22%) achieved an objective response, including 1 complete remission. Stable disease was noted in 11 patients and a minor tumor regression occurred in 1. The median survival duration of all patients was 6 months (range, 2-31+ months). AMF was well tolerated; toxicities were mild to moderate, most frequently involving nausea and vomiting, mucositis, and neutropenia with or without fever. There was no death directly attributable to chemotherapy. Although the AMF regimen used a well-documented preclinical concept of synergism between methotrexate and 5-fluorouracil, response and survival results suggest a modest activity of this combination in patients with gastric cancer. Better preclinical models are necessary for the development of effective combination chemotherapy.
Adenocarcinoma↗
Chromosome 5 allele loss at the glucocorticoid receptor locus in human colorectal carcinomas.
Matched normal/tumor DNA pairs from sporadic colon carcinoma patients were examined for chromosome 5 allele loss using a probe for a functional gene (glucocorticoid receptor = GRL) locus. This locus maps (5q11-q13) close to one of two alternative sites recently reported for a constitutional deletion in a familial adenomatous polyposis (FAP) patient. Tumor-specific allele loss of at least 27% at GRL supports the hypothesis that both hereditary and sporadic forms of colon cancer result from mutations of the same gene. The proximity of the GRL locus to the region of 5q affected in FAP and the observed tumor-specific allele loss at this locus suggest that further research is needed regarding whether genetic alterations in the glucocorticoid receptor may be associated with colon carcinogenesis.
Adenocarcinoma↗
Phase II study of fludarabine phosphate in patients with advanced colorectal carcinoma.
For phase II studies in patients with solid tumors, the National Cancer Institute recommended that the starting dose of fludarabine phosphate be 20 mg/m2/day as a short intravenous infusion for 5 days every 21 days. Twenty-one patients with untreated, advanced, measurable colorectal carcinoma received fludarabine phosphate as a 30-minute infusion at a median dose of 25 mg/m2/day (range 15-35 mg/m2/day) for 5 consecutive days repeated every three weeks. Antitumor response was evaluated following two courses of therapy. No patient achieved complete or partial response. Minor regression of lung metastases occurred for less than 12 weeks in one patient. Therapy was generally well tolerated. Frequent toxicities included lymphopenia, mild nausea and vomiting, mucositis, and anorexia. One patient died of sepsis, bleeding, and progressive disease while she was severely myelosuppressed. Neurotoxicity was not observed in any patient. Fludarabine phosphate at this schedule and dose range is inactive against colorectal carcinoma.
Adult↗
Reassignment of a cancer family syndrome gene to chromosome 18.
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Chromosome Mapping↗
Ifosfamide and mesna: marginally active in patients with advanced carcinoma of the pancreas.
Ifosfamide, an analogue of cyclophosphamide, has therapeutic activity against a wide variety of human malignancies. In a phase II trial in carcinoma of the pancreas, we treated 31 patients who had not received prior chemotherapy with a median ifosfamide dose of 2 g/m2/d (range, 1.5 to 2 g/m2/d) administered intravenously (IV) over one hour for five consecutive days every 3 weeks. 2-mercaptoethane sulphonate (mesna), an acrolein antagonist with known uroendothelial protective properties, was administered IV at a dose of 400 mg/m2 over 15 minutes before the daily dose of ifosfamide and repeated every four hours for two additional doses. Among 30 evaluable patients, one patient achieved a complete remission (26+ months) and another patient had a partial remission (4 months). The median duration of survival of all patients from the start of ifosfamide therapy was only 3 months (range, 1 to 26+ months). Treatments were generally well tolerated. The most common toxic effects included granulocytopenia, nausea and vomiting, malaise, anorexia, and mild hematuria. Mesna offers an adequate protection against uroendothelial injury caused by ifosfamide. Despite the previously reported response rate of greater than 20% at the same or lower doses of ifosfamide in other studies, our data suggest that ifosfamide is only marginally active against cancer of the pancreas and appears to be of minimal value in the treatment of patients with this tumor.
Adult↗
Familial polyposis coli: genetics, surveillance, and treatment.
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Adenomatous Polyposis Coli↗
Hereditary nonpolyposis colorectal cancer--Lynch syndromes I and II.
HNPCC is an autosomal dominantly inherited disorder with proclivity to early onset colorectal cancer in the absence of multiple polyps of the colon. There is a predilection for proximal colonic location (70 per cent) and an excess of synchronous and metachronous colorectal cancers. HNPCC is subdivided into Lynch syndrome I, which is restricted to site-specific colon cancer susceptibility, and Lynch syndrome II, which shows all of the features of Lynch syndrome I, but in addition, patients are at inordinately increased risk for carcinoma of the endometrium, ovary, and other anatomic sites. The frequency of HNPCC is conservatively estimated to be 4 to 6 per cent of the total colorectal cancer burden. Because of the fact that the family history is underreported almost uniformly in medical practice, we believe that the true frequency of this disease may be much greater. Heterogeneity may be extant with respect to tumor association, in that in certain Lynch syndrome II kindreds, carcinoma of the pancreas, kidney, breast, and other anatomic sites may predominate. Knowledge of the natural history of HNPCC predicates surveillance and management strategies. Thus, because of the early onset of and proximal predilection for colorectal cancer, we recommend initiation of colonscopy at age 25 and annually thereafter. We also recommend guaiac testing of the stool at least twice a year. In the case of Lynch syndrome II, in addition to colonscopy, we recommend intensive surveillance for the endometrium, including aspiration biopsies. Other targeted organs, depending on the tumor spectrum in the family, should be given priority attention. Because of an excess of synchronous and metachronous colorectal cancer in HNPCC, subtotal colectomy with ileorectal anastomosis is the treatment of choice for initial colorectal cancer. In women presenting with initial colorectal cancer who have completed their families, consideration should be given to prophylactic hysterectomy and bilateral salpingo-oophorectomy at the time of surgery for colorectal cancer. Needed are biomarkers of acceptable sensitivity and specificity for the genotype, because HNPCC lacks premonitory physical signs. We believe that increased knowledge about colorectal cancer etiology and carcinogenesis can be attained through the study of families prone to the Lynch syndromes.
Adult↗
Phase I study of recombinant gamma-interferon (rIFN-gamma).
A Phase I study of recombinant gamma-interferon was conducted in 35 patients with advanced malignancy. The schedule was twice weekly administered intravenously. Patients were assigned to six dose levels. The major toxicities were flu-like symptoms and were unrelated to dose. Other adverse reactions, such as myelosuppression, were dose dependent. The addition of a nonsteroidal anti-inflammatory agent did not ameliorate the symptoms at the highest dose level. Antitumor effects occurred in patients with gastric, duodenal, and breast carcinoma.
Drug Evaluation↗