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Background: Molecular genetic analysis of DNA in patient stools has been proposed for screening of colorectal cancer (CRC). Because nonapoptotic cells shed from tumors may contain DNA that is less degraded than DNA fragments from healthy colonic mucosa, our aim was to show that DNA fragments isolated from stools of patients with CRC had higher integrity than DNA isolated from stools of patients with healthy colonic mucosa., Methods: We purified DNA from the stools of a colonoscopy-negative control group and patients with CRC and examined the relationship between long DNA fragments and clinical status by determining stool DNA integrity, using oligonucleotide-based hybrid captures with specific target sequences in increasingly long PCR reactions (200 bp, 400 bp, 800 bp, 1.3 kb, 1.8 kb, 24 kb). DNA fragments obtained from CRC patients were compared with fragments obtained from colonoscopy-negative individuals for length and/or integrity., Results: DNA fragments isolated from CRC patients were of higher molecular weight (>18 bands detected of a total of 24 possible bands) than fragments isolated from fecal DNA of the colonoscopy-negative control group., Conclusions: The presence of long DNA fragments in stool is associated with CRC and may be related to disease-associated differences in the regulation of proliferation and apoptosis. An assay of fecal DNA integrity may be a useful biomarker for the detection of CRC.

Background: Urinary cytology has long been used as a noninvasive screen for the detection of urinary tract cancer but is limited by the generation of false positive and false negative results. More recently, molecular changes associated with urothelial neoplastic progression have been identified in DNA from urine sediments, demonstrating an alternative approach for identifying neoplastic change in the bladder., Purpose: The purpose of this prospective study was to determine the value of detection of H-ras (also known as HRAS) mutations in urine sediment DNA as a clinical indicator of tumor presence, recurrence, and/or progression., Methods: Urine sediments were collected from 100 patients presenting with bladder tumors, with follow-up samples collected from 19 patients. DNA extracted from urine sediments was analyzed for changes in exon 1 of the H-ras gene, using single-strand conformation polymorphism (SSCP) analysis. A representative number of aberrant H-ras/SSCP migrating bands were excised and sequenced to confirm the presence of a mutation. Human bladder specimens were obtained from patients (93 of the 100 patients initially and 18 of the 19 patients studied by follow-up) and histologically evaluated for tumor content and grade., Results: Mutations in exon 1 of the H-ras gene were detected in urine sediments from 44% (44 of 100) of the patients; concordant results were obtained by cytologic analysis, where 33% (31 of 93) of the patients displayed positive cytology. Analysis of the distribution of abnormalities with tumor grade revealed greater detection of low-grade (1-2) lesions using ras analysis (47%) compared with cytology (16%). In contrast, cytology was more effective in identifying the presence of carcinoma in situ. Combined results from these two approaches substantially increased the sensitivity of tumor detection, resulting in the identification of tumors in 60% of patients., Conclusions: Identification of H-ras mutations in DNA from urine sediments facilitates the detection of low-grade bladder tumors and, in combination with cytology, increases the overall tumor detection from 33% to 60%. Preliminary results in patient follow-up suggest that detection of H-ras mutations may have some clinical utility in detecting the presence of abnormal cells in the absence of an overt lesion following cystoscopy or positive cytology.

Neoplastic transformation of C57BL/lcrf-a' mouse bladder epithelium was induced in long-term primary cultures by a single 24-hour treatment with 7,12-dimethylbenz[a]anthracene on day 2 of culture. Transformed foci appeared earlier (40--60 days) and at a higher frequency (28%) in cultures from old donors (28--30 mo) compared with 100 days and 0.9% in cultures from young adult donors (5--7 mo). After transplantation into syngeneic mice, transformed cells produced carcinomas. Spontaneous epithelial transformation occurred in dimethyl sulfoxide-treated old cultures after the same interval (40--60 days) as in the carcinogen-treated cultures but at a lower frequency (5.3%). Spontaneous epithelial transformation did not occur in cultures from young donors.

Monoclonal antibodies to human bladder carcinoma membrane antigens were produced by fusion of MOPC-21 NS/1 mouse myeloma cells with spleen cells from BALB/c mice immunized against a crude membrane extract from a metastatic bladder carcinoma. Hybrids were screened for antibody production in a solid-phase radioimmunoassay and selected for their reactivity with subpopulations of urothelial cells on normal bladder tissue sections. Three antibody groups were defined: Group I (4-72-2) was urothelium specific and stained the basal and intermediate cells in normal urothelium; group II (3-48-2, 48-1, and 3-50-3) showed reactivity with intermediate and superficial cells; group III (8-30-3, 77-1, 2-94-2, 3-71-1, and 94-3) was restricted to antigens on the luminal membrane of superficial cells. All antibodies recognized antigenic determinants in fixed paraffin-embedded material and within groups showed a range of staining patterns in other tissues. Studies on sections representing different stages of neoplastic progression showed disruption in the antibody-staining pattern in urothelium and, in all cases, a strong distinct staining of invasive tumor areas and metastatic secondary tumors. Biochemical analysis of the antigens defined at least three antigenic systems, two of which consisted of molecules having Mr of 250,000 and 300,000 as judged by Western blot analysis. Antigenic determinants recognized by some antibodies (3-48-2, 48-1, 3-50-3, 8-30-3, 77-1, and 3-71-1) were shown to be carbohydrate by reactivity with glycolipid fraction and suggest that antibodies within groups recognize different epitopes on the same molecule.