Neoplastic Colonic Cells Research Articles

Hypothesis: Induction of biomarkers for detection of colonic neoplasms.

The signing of the National Cancer Act of 1971 by President Nixon marked the beginning of our war on cancer. More than 45 years later, the war is still going steady, with the enemy being almost as strong as in 1971. Furthermore, the increasing rates of obesity not only among adults, but among children and adolescents, are the likely cause for the 30-year trend of colon cancer (CC) becoming a disease of the younger population in the U.S. These trends, however, have not spurred the development of novel screening approaches for CC. Considering the need for a sensitive and non-invasive detection of early stage neoplastic lesions in the colon, we propose the development of a test based on a novel concept - the concept of induced biomarkers. The proposal is based upon our findings that the food additives propolis and gamma-cyclodextrin (gCD) (a) decrease the neoplastic burden in normal weight and obese ApcMin mice, a model of early stage intestinal neoplasia, and (b) elicit significant changes in the serum proteome in ApcMin mice. We posit that gCD and propolis induce the release of neoplasm-associated biomarkers in systemic circulation (e.g., metabolites, neoplastic, apoptotic, and immune response proteins), and these markers could be used to detect early stage intestinal neoplasms. Additional dietary bioactives may also elicit a complement of induced markers. The hypothesis could be ascertained by utilizing a mouse model, the Apc+/1638Nmice, as well as through human subject studies that integrate proteomics and metabolomics analyses. The concept of detecting inducible markers of colonic neoplasms is novel, and is substantiated by the significant physiological effects of gCD and propolis on neoplastic colonic cells in culture and on early neoplastic development in ApcMinmice. The long-term objective is to develop a minimally invasive method that detects early stage neoplastic development in the human colon.

56 Performance of a novel molecular stool screening test, the faecal cologuard® in a cohort of irish symptomatic and surveillance patients

Background Screening tests for precancerous polyps and early CRC reduce mortality. Cologuard is a stool-based, commercially available, molecular screening tool that detects occult blood in combination with multiple DNA abnormalities released from neoplastic colonic cells (from small polyps to cancers). Previous population-based studies reported a sensitivity and specificity of 69%–92% and 87% respectively for detection of polyps. Aim To evaluate the Cologuard in asymptomatic low risk surveillance and symptomatic patients. Method Ethics approval was obtained and patients were recruited from endoscopy referrals and the colonoscopy surveillance waiting list. Inclusion and exclusion criteria in Table 1. Participants provided stool for Cologuard prior to colonoscopy. Cologuard and Colonoscopy results were correlated to calculate NPV, PPV, sensitivity and specificity. Results 60 patients were recruited. To date 40 have completed the study. 22 (55%) female. Median age 60 years (range 42–80). 18 (45%) patients were symptomatic. Colonoscopy adenoma detection rate was 28% (n=11). Cologuard was positive in 10 (25%) patients, 4 of whom had adenomatous polyps, 1>10 mm size and 3 1 cm in size, 1=7 mm and 5 5 mm. No CRC was diagnosed. Conclusions Cologuard seems reliable for excluding CRC and adenomatous polyps>5 mm in size, and maybe useful in triaging surveillance patients for Colonoscopy.

Further studies on the arrest of cell proliferation in tumor cells at the invading front of colonic adenocarcinoma

The author has previously reported that neoplastic glands at the leading invading edge of colorectal carcinomas often display flat tumor cells and cellular gaps called glandular pores. The aim of this study was to audit cell proliferation and p53 mutation in flat tumor cells and in tumor cells at the tip of glandular pores at the leading invading front of colonic carcinomas. Sections from 40 colonic adenocarcinomas were immunostained with the proliferation marker Ki67 and with p53 protein. Expression was assessed at the leading invading front in consecutive neoplastic glands having flat tumor cells and epithelial pores and in neoplastic glands showing neither flat tumor cells nor glandular pores. Flat tumor cells in neoplastic glands usually showed no Ki67 expression but overexpressed p53 mutation. In neoplastic glands with pores 40% of the tumor cells at the tip of the pores showed no Ki67, but they overexpressed p53 mutation. The results showed, for the first time, that p53-positive flat neoplastic colonic cells arrest their proliferation at the invading front. It is possible that these p53-positive/Ki67-negative neoplastic cells were temporarily removed from the cell cycle (G0). This paradoxical biological behavior of tumor cells might be connected with the formation of glandular pores and appears to indicate that arrest of cell proliferation at the advancing tumor front in colonic carcinomas occurs independently of p53 mutation. The possible existence of two independent molecular systems at the advancing tumor edge of colonic carcinomas, one supervising cell proliferation and the other zealously transferring the p53 mutation to daughter cells, is suggested.

Dietary resistant starch and chronic inflammatory bowel diseases.

These studies were performed to test the benefit of resistant starch on ulcerative colitis via prebiotic and butyrate effects. Butyrate, propionate, and acetate are produced in the colon of mammals as a result of microbial fermentation of resistant starch and other dietary fibers. Butyrate plays an important role in the colonic mucosal growth and epithelial proliferation. A reduction in the colonic butyrate level induces chronic mucosal atrophy. Short-chain fatty acid enemas increase mucosal generation, crypt length, and DNA content of the colonocytes. They also ameliorate symptoms of ulcerative colitis in human patients and rats injected with trinitrobenzene sulfonic acid (TNBS). Butyrate, and also to a lesser degree propionate, are substrates for the aerobic energy metabolism, and trophic factors of the colonocytes. Adverse butyrate effects occur in normal and neoplastic colonic cells. In normal cells, butyrate induces proliferation at the crypt base, while inhibiting proliferation at the crypt surface. In neoplastic cells, butyrate inhibits DNA synthesis and arrests cell growth in the G1 phase of the cell cycle. The improvement of the TNBS-induced colonic inflammation occurred earlier in the resistant starch (RS)-fed rats than in the RS-free group. This benefit coincided with activation of colonic epithelial cell proliferation and the subsequent restoration of apoptosis. The noncollagenous basement membrane protein laminin was regenerated initially in the RS-fed group, demonstrating what could be a considered lower damage to the intestinal barrier function. The calculation of intestinal short-chain fatty acid absorption confirmed this conclusion. The uptake of short-chain fatty acids in the colon is strongly inhibited in the RS-free group, but only slightly reduced in the animals fed with RS. Additionally, RS enhanced the growth of intestinal bacteria assumed to promote health. Further studies involving patients suffering from ulcerative colitis are necessary to determine the importance of RS in the therapy of a number of intestinal diseases and the maintenance of health.

Detection of oncogene mutation from neoplastic colonic cells exfoliated in feces.

Best chances of a cure from colorectal cancer are obtained before metastatic spread. Lack of specific tests allowing early diagnosis of the tumor accounts for investigation of gene alterations involved in carcinogenesis by a noninvasive method. In the present study, K-ras codons 12 and 13 mutations were studied in neoplastic cells shed from the bowel into the stool and those contained in the tumor and normal mucosa. Moreover, healthy patients and a few others with precancerous conditions were examined. Stool, tumor, and mucosa samples were taken from 25 patients with colorectal adenocarcinoma. Stool and mucosa samples were obtained from 11 healthy patients, and stool, pathologic bowel tissue, and normal mucosa samples were obtained from 3 patients with adenoma (1) or ulcerative colitis (2). Polymerase chain reaction amplification and restriction enzyme analysis were performed. K-ras codon 12 mutations were detected in both tumor and stool samples of 10 cancer patients, and no gene alterations were observed in 14 patients. In one patient with a tumor, a mutation was shown in only the tumor tissue. The agreement rate in tumor and stool analysis was 96 percent. A normal pattern of K-ras codons 12 and 13 was observed in the bowel mucosa. All stool and mucosa samples from healthy patients were not altered in K-ras. Agreement was registered between samples taken from patients with preneoplastic lesions. These preliminary findings show a high rate of accuracy in the investigation of K-ras alterations in the colorectal cells shed into the feces, suggesting that such an approach could be used to study other gene alterations and, prospectively, to identify early colorectal cancers.

Abnormal goblet cell glycoconjugates in rectal biopsies associated with an increased risk of neoplasia in patients with ulcerative colitis: early results of a prospective study.

A group of 18 patients with stable ulcerative colitis involving the entire colon for at least eight years was subjected to a biopsy of normal appearing rectal mucosa and followed prospectively over four years for the development of either dysplasia or cancer. Goblet cell glycoconjugate structure was examined in the rectal biopsies using fluorescein conjugated lectins. At the beginning of the study, 13 of the 18 patients had abnormalities of goblet cell mucin or cytoplasmic glycoconjugates in the rectal biopsies. Dysplasia subsequently developed in six and carcinoma in one of these patients. Among the five patients with normal lectin binding studies in the initial rectal biopsies, colonic dysplasia has subsequently developed in one. The abnormalities seen in the rectal goblet cells resembled in part those previously seen in immature and neoplastic colonic cells. The dysplastic tissues all contained the form of mucin which has been found in other neoplastic colonic tissues. This preliminary report after four years of prospective study suggests that abnormalities of glycoconjugate structure may be associated with, and may precede, neoplastic events in the setting of chronic ulcerative colitis.

Glycoproteins of cultured epithelial cells from human colonic adenocarcinoma and fetal intestine

The molecular weight distribution and Concanavalin A binding properties of labeled glycopeptides and glycoproteins from cell surface membranes, the cytoplasmic fraction and culture media were studied in human fetal and neoplastic colonic cells. Cells were labeled by culturing cells in the presence of [ 14C]-or[ 3 H]-labeled glucosamine or fucose. Both fucose and glucosamine were incorporated into the membrane glycoprotein fraction of the colonic cancer cells to a much lesser extent than into fetal cells. The elution profile obtained from Bio-gel P- 150 column chromatography indicated that colonic cancer cell membranes contain fucose- and glucosamine-labeled, trypsin labile, high molecular weight glycopeptides not present in fetal cells. Affinity chromatographic studies of membrane glycopeptides using agarose-bound Concanavalin A also indicated that cell surface membranes from fetal and cancerous colonic cells contain not only glycoproteins of different molecular weights, but glycoproteins having different oligosaccharide side chains. These results indicate that there are significant quantitative and qualitative differences in cell surface glycoproteins between fetal and cancerous intestinal cells.

Human colonic adenocarcinoma cells. I. Establishment and description of a new line.

A series of human colonic epithelial cell lines have been cultured from a single patient: LS-180 the original adenocarcinoma, LS-174T a trypsinized variant, and normal colonic tissue. The malignant cells, 20 to 40, mum in diameter and oval to polygonal, exhibited characteristics of normal colonic mucosal cells, namely, abundant microvilli prominent in secretory cells, and the presence of intracytoplasmic mucin vacuoles. The cultured adenocarcinoma cells, but not normal, demonstrated neoplastic properties by producing high levels of carcinoembryonic antigen (CEA) and by the ability to be propagated in hamster cheek pouches and in immunodeprived mice. The CEA production by the newly established line LS-180 released 900 times more CEA per cell into the culture medium and bore 30 times more cell-associated material than the established line, HT-29. These cell lines may permit detection of distinctive chemical, physiological, pharmacologic, and immunologic characteristics of neoplastic colonic cells.