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Biomedical subjects

A M Shamsuddin

Publications and source records attributed to A M Shamsuddin.

At least 19 recordsLinked to original sources

Absorption and excretion of orally administered inositol hexaphosphate (IP(6) or phytate) in humans.

A study of the pharmacokinetic profile (oral absorption and renal excretion) of inositol hexaphosphate or phytate (IP(6)) is presented. Seven healthy volunteers were following a IP(6) poor diet (IP(6)PD) in a first period, and on IP(6) normal diet (IP(6)ND) in a second one. When following the IP(6)PD they become deficient in IP(6), the basal levels found in plasma (0.07+/- 0.01 mg/L) being clearly lower than those found when IP(6)ND was consumed (0.26+/- 0.03 mg/L). During the restriction period the maximum concentration in plasma were obtained 4 h after the ingestion of a single dose of IP(6), observing almost the same renal excretion profiles for the three different commercial sources and doses. After the IP(6) restriction period, volunteers were on IP(6)ND, reaching normal plasma and urinary IP(6) values in 16 days. Thus, the normal plasma and urinary concentrations, can be obtained either by consumption of a IP(6)ND taking a long time or in a short period by IP(6) supplements.

Absorption↗

Comparison of different techniques for detection of Gal-GalNAc, an early marker of colonic neoplasia.

The tumor marker, D-galactose-beta [1-3]-N-acetyl-D-galactosamine (Gal-GalNAc, also known as T-antigen) can be identified by a very simple galactose oxidase-Schiff's (GOS) reaction either on tissues or on rectal mucus samples from patients with colorectal neoplasms. Gal-GalNAc is expressed in the neoplastic mucosa as well as the remote non-neoplastic mucosa. It is, however, not expressed in colonic mucosa of normal subjects. We studied the expression of Gal-GalNAc by GOS reaction, lectin reactivity and immunocytochemistry in 10 normal, .45 precancerous [5 Crohn's disease, 15 ulcerative colitis (5 without dysplasia and 10 with dysplasia), 25 tubular adenomas], and 25 adenocarcinoma cases. Normal mucosa remote from tubular adenoma and adenocarcinoma was also studied. The GOS method was compared with reactivity of the lectin jacalin and immunostaining with antibody to T antigen (Anti-Tag Ab). GOS reaction was negative in all of the 10 normal specimens. Of the 5 Crohn's disease specimens, 2 were positive and 3 negative. In the 5 ulcerative colitis cases without dysplasia, positive reaction was seen in 2 cases and negative in 3. Of the 10 cases of ulcerative colitis with dysplasia, 5 showed positivity in dysplastic areas, and 3 of these were also positive in remote non dysplastic mucosa. Twenty of 25 tubular adenomas yielded a positive reaction in the adenoma, 14 of them showing positivity also in remote mucosa; 3 cases showed a positive reaction only in remote mucosa. Of the 25 adenocarcinomas, 21 showed a positive reaction in the adenocarcinoma as well as the remote mucosa. GOS reaction was intense in well differentiated adenocarcinoma and weak in poorly differentiated adenocarcinoma. Intense reaction was also seen in the intracellular mucus of some aberrant crypts and morphologically normal crypts remote from adenocarcinoma and tubular adenoma. GOS reaction showed an overall sensitivity of 75.7% and specificity of 100% for cancer and precancerous lesions. Jacalin reactivity was slightly more sensitive (84.3%) but less specific (80%) and Tag Ab reactivity even less sensitive (50%) but as specific (100%) for neoplastic and dysplastic mucosa. We conclude that the detection of the carbohydrate moiety Gal-GalNAc varies with the technique used. Compared to other techniques, GOS reaction is extremely simple and has a high degree of sensitivity and specificity. It can be used for detection of this tumor marker in remote non-neoplastic mucosa of patients with neoplasia or at risk of developing neoplasia. It, therefore, could be used as a cost effective screening test in rectal biopsy specimens of such patients.

Adenocarcinoma↗

IP6: a novel anti-cancer agent.

Inositol hexaphosphate (InsP6 or IP6) is ubiquitous. At 10 microM to 1 mM concentrations, IP6 and its lower phosphorylated forms (IP(1-5)) as well as inositol (Ins) are contained in most mammalian cells, wherein they are important in regulating vital cellular functions such as signal transduction, cell proliferation and differentiation. A striking anti-cancer action of IP6 has been demonstrated both in vivo and in vitro, which is based on the hypotheses that exogenously administered IP6 may be internalized, dephosphorylated to IP(1-5), and inhibit cell growth. There is additional evidence that Ins alone may further enhance the anti-cancer effect of IP6. Besides decreasing cellular proliferation, IP6 also causes differentiation of malignant cells often resulting in a reversion to normal phenotype. These data strongly point towards the involvement of signal transduction pathways, cell cycle regulatory genes, differentiation genes, oncogenes and perhaps, tumor suppressor genes in bringing about the observed anti-neoplastic action of IP6.

Animals↗

Comparison of pure inositol hexaphosphate and high-bran diet in the prevention of DMBA-induced rat mammary carcinogenesis.

Inositol hexaphosphate (IP6), abundant in cereals and legumes, has been demonstrated to be a promising anticancer agent in different in vivo and in vitro models. Because IP6 is particularly abundant in the bran part of certain mature seeds such as wheat, we investigated whether a high-fiber bran diet containing high IP6 shows a dose-response inhibition of 7,12-dimethylbenz[a]anthracene (DMBA)-induced rat mammary carcinogenesis. Starting at two weeks before DMBA intubation, rats were divided into five groups and fed AIN-76A diet only or AIN-76A diet containing 5%, 10%, or 20% Kelloggs' All Bran; the fifth group received 0.4% IP6 given in drinking water, an amount equivalent to the IP6 content in 20% bran. After carcinogen administration, the rats remained on these regimens for 29 weeks. Compared with the carcinogen control, at 29th week, tumor incidence was reduced by 16.7%, 14.6%, and 11.4% in rats fed 5%, 10%, and 20% bran, respectively (not statistically significant). However, rats given 0.4% IP6 in drinking water, equivalent to that in 20% bran, had a 33.5% reduction in tumor incidence (p < 0.02) and 48.8% fewer tumors (p < 0.03). These data show that supplemental dietary fiber in the form of bran exhibited a very modest, statistically nonsignificant inhibitory effect, which was also not dose dependent. In contrast, animals given IP6 showed significant reduction in tumor number, incidence, and multiplicity. Thus IP6 an active substance responsible for cereal's beneficial anticancer effect, is clearly more effective than 20% bran in the diet. In practical terms, intake of IP6 may be a more pragmatic approach than gorging enormous quantities of fiber for cancer prophylaxis.

9,10-Dimethyl-1,2-benzanthracene↗

Gal-GalNAc: a biomarker of colon carcinogenesis.

The disaccharide tumor marker Gal-GalNAc visualized by galactose oxidase-Schiff sequence is commonly present in cancer cells and in rectal mucous of patients with colon cancer. The expression of this marker on tissue sections taken during experimental colon carcinogenesis shows excellent correlation with human precancerous lesions and even higher percentage of colon cancers express this marker, whereas, no expression is seen in the normal human large intestine. Multifocal expression of the marker is seen throughout the entire colon of patients with precancer and cancer; these include dysplasia, dilated and distorted crypts, regenerative dysplasia and hyperplastic crypts, as well as the morphologically normal crypts remote from cancer. Nearly identical pattern of Gal-GalNAc expression throughout the entire colon also appear during rat colon carcinogenesis induced by azoxymethane including non-expression by the normal and regenerative epithelia during wound healing following mechanical injury. Thus, Gal-GalNAc detected by the simple technique of galactose oxidase-Schiff sequence, is a biomarker that appears during the very early stages of progression of carcinogenesis. The expression pattern supports the field effect theory of carcinogenesis and also explains the basis for mass screening for cancer and precancerous conditions. Chemoprevention strategy using Gal-GalNAc as an intermediate marker detected by accurate and cost-effective rectal mucus test may have great potential.

Adenoma↗

Common expression of the tumor marker D-galactose-beta-[1-->3]-N-acetyl-D-galactosamine by different adenocarcinomas: evidence of field effect phenomenon.

The simple carbohydrate tumor marker D-galactose-beta-[1-->3]-N-acetyl-D-galactosamine (Gal-GalNAc) can be easily identified by a sequential galactose oxidase (GO)-Schiff reaction either on tissues or on rectal mucus samples from patients with colorectal cancer. To check the usefulness of this marker and technology in identifying cancers and precancers of other organs, we have assessed the differential expression of Gal-GalNAc in various adenocarcinomas and their corresponding normal tissues. The expression of Gal-GalNAc determined by GO-Schiff sequence was examined in a total of 133 tissue samples from 81 cases of the adenocarcinomas of the breast, ovary, pancreas, stomach, and endometrium and 52 cases of respective normal controls. None of the 52 cases of normal tissues (except 15 cases of stomach) showed expression of Gal-GalNAc. In contrast, 100% of adenocarcinomas from the breast (19 of 19), ovary (15 of 15), and pancreas (6 of 6), 94.1% of stomach (16 of 17) cancers, and 91.7% (11 of 12) of uterine adenocarcinomas expressed Gal-GalNAc. The expression of Gal-GalNAc in cancerous tissues was mostly strong and widespread and was distributed in both secreted mucin and cytoplasmic mucin droplets. The normal epithelia and their secretions in the vicinity of the carcinoma (within the "field") in the breast, bronchus, endometrium, and pancreatic duct also expressed Gal-GalNAc in contrast to normal tissues obtained from noncancerous individuals, which were totally nonreactive. It is concluded that the tumor marker Gal-GalNAc recognized by GO-Schiff sequence was highly expressed not only by a variety of adenocarcinomas but also by the apparently normal-appearing epithelia and their secretions in the vicinity of carcinomas, strongly suggesting a field effect phenomenon of carcinogenic agent(s). Identification of the marker in these secretions may have great potential in our strategies for mass screening for those cancers.

Adenocarcinoma↗

Inositol hexaphosphate and inositol inhibit DMBA-induced rat mammary cancer.

Because inositol hexaphosphate (InsP6) and inositol (Ins), contained in plants and most mammalian cells, have been demonstrated to have anti-cancer and anti-cell proliferative action in several experimental models of carcinogenesis we have examined the effect of InsP6 +/- Ins on DMBA-induced rat mammary tumor model. Starting two weeks prior to induction with DMBA, the drinking water of female Sprague-Dawley rats was supplemented with either: 15 mM InsP6, 15 mM Ins, or 15 mM InsP6 + 15 mM Ins; a control group received no inositol compounds. Animals (49-day-old) were given a single intragastric dose of DMBA (5 mg/rat) in 1 ml of corn oil administered by oral intubation. After 45 weeks of treatment, the animals in all the three treatment regimens showed a significant reduction (P < 0.05) in tumor incidence. Tumor number, multiplicity and tumor burden were also significantly (P < 0.05) reduced by InsP6 +/- Ins. When all the parameters were taken into consideration, the best results were obtained by the combination treatment of InsP6 + Ins. Four additional groups not receiving DMBA, but drinking tap water, InsP6, Ins, or InsP6 + Ins of the same molarity as experimental groups were observed for the duration of the study to monitor for any toxicity following this long-term treatment; no significant toxicity as evaluated by body weight gain, serum and bone mineral levels was detected. We demonstrate that InsP6 +/- Ins reproducibly inhibits experimental mammary carcinoma, therefore having great potential as a chemopreventive and adjuvant therapeutic agent for this disease as well.

9,10-Dimethyl-1,2-benzanthracene↗

Inositol hexaphosphate inhibits growth and induces differentiation of PC-3 human prostate cancer cells.

We investigated the effects of inositol hexaphosphate (InsP6) on growth inhibition and differentiation of human prostate cancer cells PC-3 in vitro. A significant dose- and time-dependent growth inhibition was observed as tested by the MTT-incorporation assay (P < 0.05 at 1 mM InsP6 after 24 h treatment, P < 0.01 at 0.1 mM after 3 days). DNA synthesis as determined by [3H]thymidine incorporation assay was also suppressed by InsP6 in a dose-dependent manner, occurring as early as 3 h after treatment and continuing up to 48 h (P < 0.01 at 1 mM InsP6). A 9- to 10-fold increase (P < 0.01) in expression of HLA class I molecule associated with tumor immunosurveillance and cell differentiation was induced by InsP6. The marker for prostatic cell differentiation, prostate acid phosphatase, was significantly (P < 0.05) increased after 48 h treatment at 0.5-5 mM InsP6. Since InsP6 strongly inhibits growth and induces differentiation in human prostate cancer cells in vitro, in vivo studies using a tumor xenograft model and a prostate carcinogenesis model are warranted to validate the efficacy of InsP6 in the treatment and prevention of prostate cancer.

Acid Phosphatase↗

Inositol phosphates have novel anticancer function.

Inositol hexaphosphate (InsP6, phytic acid) is ubiquitous in the plant kingdom and is abundant in cereals and legumes. In much smaller amounts InsP6 and its lower phosphorylated forms (InsP1-5) are contained in most mammalian cells, where they are important in regulating vital cellular functions. Both in vivo and in vitro experiments have suggested striking anticancer potential (preventive as well as therapeutic) for InsP6 with and without inositol. In addition to reduce cell proliferation, InsP6 increases differentiation of malignant cells often resulting in reversion to the normal phenotype. InsP6 is quickly absorbed from the rat stomach and upper intestine and distributed as inositol and InsP1. In vitro it is instantaneously taken up by malignant cells undergoing variable dephosphorylation to inositol and InsP1-5, pointing toward their role in mediating the action of InsP6. Because InsP6 is high in high-fiber diets, our studies also may explain, at least in part, the epidemiologic observation showing high-fiber diets are associated with a lower incidence of certain cancers. Although further studies are needed to elucidate the mechanism(s) of this action, inclusion of InsP6 in our strategies for cancer prevention and therapy is warranted.

Animals↗

A new murine monoclonal antibody, CMU10, as a marker for colonic carcinoma and precancerous conditions.

OBJECTIVE: To investigate the usefulness of a cancer-associated mucin antigen using a new monoclonal antibody, CMU10, as a tumor marker. Expression was assessed in normal adult, fetal, hyperplastic, preneoplastic, and neoplastic tissues of colon. DESIGN: CMU10 monoclonal antibody recognizes a mucin antigen that is not expressed in normal fetal and adult large intestine, but is rather commonly expressed in cancerous and precancerous lesions. Immunocytochemical analysis was performed on human tissues obtained at surgery or at autopsy. RESULTS: Expression of this mucin antigen was observed in 27 (98.4%) of 28 cases of colorectal carcinoma, 24 (96%) of 25 cases of adenomatous polyps, 9 (75%) of 12 cases of ulcerative colitis, and 9 (100%) of 9 cases of hyperplastic polyps. In cancerous specimens, the antigen distribution was mainly localized in the secretory mucin and surface membrane, whereas in precancerous lesions it was located in dysplastic, dilated, and distorted crypts. CONCLUSIONS: Because CMU10 differentially recognizes an antigen in cancerous and precancerous tissues, but not in normal tissues, it may be useful as a tumor marker for immunodiagnosis and, hence, early detection.

Adenomatous Polyps↗

[3H]inositol hexaphosphate (phytic acid) is rapidly absorbed and metabolized by murine and human malignant cells in vitro.

To test the hypothesis that the antineoplastic activity of phytic acid [inositol hexaphosphate (InsP6)] is a result of rapid intake by the cells and its conversion to lower inositol phosphates (InsP1-5), thereby affecting the intracellular inositol phosphate pool, YAC-1 (mouse T cell leukemia), K562 (human erythroleukemia) and HT-29 (human colon adenocarcinoma) cell lines were incubated at 37 degrees C with [3H]InsP6. After 1 h, 31.3 +/- 3.1% of administered radio-activity was taken up by YAC-1 cells, 6.2 +/- 0.9% by K562 cells and 6.6 +/- 3.8% by HT-29 cells. Differential centrifugation and high resolution subcellular fractionation of cell homogenates demonstrated that within the various cellular compartments, 80% (HT-29) to 97% (YAC-1) of the total radioactivity was in the cytosol. Kinetic study showed that the peak of the total absorption was obtained after 30 min of cell exposure to radiolabeled InsP6, after with a plateau was reached. Analysis of the radioactivity accumulated within the cells showed variable proportions of myo-inositol and InsP1-6, with a preponderance of InsP1 and InsP2. The presence of [3H]myo-inositol and [3H]InsP1-6 suggests that InsP6 may, in some cells at least, be absorbed as such and that a variable degree of dephosphorylation of InsP6 takes place both extra- and intracellularly.

Adenocarcinoma↗

Expression of the tumor marker D-galactose-beta-[1-->3]-N-acetyl-D-galactosamine by premalignant and malignant prostate.

Accurate and consistent discrimination of prostatic carcinomas from benign lesions and vice versa continues to be a vexing problem in diagnostic pathology. We have tested the usefulness of the tumor marker D-galactose-beta-[1-->3]-N-acetyl-D-galactosamine in differentiating the benign from the malignant and premalignant lesions of the prostate. A sequential galactose oxidase technique (overnight incubation), followed by Schiff's reaction (15 minutes), was done on deparaffinized tissue sections of 65 carcinomas, 25 hyperplasias, 11 foci of adenosis, and 10 normal specimens. While none of the 35 benign prostates and 11 foci of adenosis expressed D-galactose-beta-[1-->3]-N-acetyl-D-galactosamine (100% specificity), 62 (95.4% sensitivity) of 65 adenocarcinomas variably expressed the marker. We therefore propose that this simple technique may have potential use in routine histopathological analysis of prostatic specimens. This marker may also serve as the basis of assays for early detection of prostatic malignancies.

Adult↗

Inhibition of rat mammary carcinogenesis by inositol hexaphosphate (phytic acid). A pilot study.

Since phytic acid (inositol hexaphosphate, InsP6) and inositol (Ins) have been demonstrated to have anti-tumor and anti-cell proliferative action in several experimental models of carcinogenesis, in a pilot study we have examined their effect on 7,12-dimethylbenz(a)anthracene (DMBA)-induced rat mammary tumor model. Starting a week prior to induction with DMBA, the drinking water of female Sprague-Dawley rats was supplemented with either: 15 mM InsP6, 15 mM Ins, or 15 mM InsP6 + 15 mM Ins; a control group received no inositol compounds. Animals (55-day-old) were given a single dose of DMBA (20 mg) in 1 ml of sesame oil by oral intubation. Four additional groups not receiving DMBA, but drinking tap water, InsP6, Ins, or InsP6 + Ins of the same molarity as experimental groups were observed for the duration of the study to monitor for any putative toxicity following this long-term treatment. As opposed to the DMBA-only group, rats treated with InsP6 +/- Ins showed a 48% reduction in the number of tumors/tumor bearing animal (tumor multiplicity) and a 40% reduction in the number of tumors/rat. In contrast to 20% rats in DMBA-only group, only 0-8% animals in the treatment group had 5 or more tumors. Likewise, the tumor incidence was reduced by 19% in InsP6 +/- Ins as compared to control untreated animals. The tumors in the treated groups were also 16% smaller in size. Data from this pilot study suggest that in addition to being effective against colon cancer, InsP6 +/- Ins may be protective against mammary carcinoma as well; additional studies are however warranted.

9,10-Dimethyl-1,2-benzanthracene↗

Tumor promotion by fecapentaene-12 in a rat colon carcinogenesis model.

Fecapentaenes are a group of fecal mutagens produced by anaerobic microflora of the colon. The potential of fecapentaene-12 (FP-12) to promote tumor development was tested in a rat colon carcinogenesis model using N-methyl-N-nitrosourea (MNU) as the initiating agent. Two groups of female F-344 rats were initiated by intrarectal instillations of MNU (2 mg in 0.5 ml H2O, 3 times a week, for 3 weeks; MNU and MNU + FP-12 groups). Two additional groups (FP-12 and Control) were given H2O without carcinogen. In the post-initiation phase, rats of the MNU + FP-12 and FP-12 groups were intrarectally administered 400 ng of FP-12 in 0.5 ml T-E buffer, twice a week, for 24 weeks, whereas the MNU and Control groups received the vehicle only. Tumors were found only in the MNU and MNU + FP-12 groups, their number being higher in the latter. The number of carcinoma bearing rats as well as the average number of carcinomas per rat were significantly higher (P < 0.05) in the MNU + FP-12 group as compared to the MNU-alone values. Aberrant crypt foci (ACF) were found in all carcinogen-treated rats, including those that did not contain tumors, whereas none were observed in the FP-12 and Control groups. The average number of ACF/cm2 was also significantly higher in the MNU+FP-12 group, as was the case for the average number of ACF containing > 10 aberrant crypts per focus. These findings suggest that FP-12 can express promoting activity in chemical induced colon carcinogenesis.

Animals↗

Growth inhibition and differentiation of HT-29 cells in vitro by inositol hexaphosphate (phytic acid).

Inositol hexaphosphate (InsP6 or phytic acid) has been shown to have antineoplastic action in in vivo models of colon carcinogenesis. We therefore investigated its effect on proliferation and differentiation of the human colon cancer cell line HT-29 in vitro. Proliferation was evaluated by neutral red incorporation assay, and differentiation was assessed by expression of the markers, cytokeratin, carcinoembryonic antigen (CEA) and beta-D-galactose-[1-->3]-N-acetyl-galactosamine (Gal-GalNAc). InsP6 in the culture media (0.66-10 mM) inhibited cell proliferation in a dose-dependent manner (P < 0.001), while inositol or inositol hexasulfate used as controls or media without InsP6 did not show any suppressive effect. The expression of the tumor marker, Gal-GalNac, was augmented (100.7% increase) by low dose (0.66 mM) of InsP6 but was subsequently suppressed with higher concentrations of InsP6. The expression of cytokeratin and CEA were both augmented by either InsP6 or inositol at all concentrations tested, although the degree of augmentation was milder with inositol than with InsP6. The combination of InsP6 and inositol (both 0.66 mm) resulted in augmentation (P < 0.001) of cytokeratin expression, while that of CEA remained unchanged. The inhibitory effect of InsP6 on cell proliferation was not altered by combination with additional inositol at any concentrations tested. Our results show that InsP6 inhibits cell proliferation and concomitantly increases differentiation and is therefore a candidate chemopreventive and chemotherapeutic agent for human large intestinal cancer.

Adenocarcinoma↗

[3H]phytic acid (inositol hexaphosphate) is absorbed and distributed to various tissues in rats.

To understand the mechanism of antineoplastic action of phytic acid, we investigated the absorption and distribution of myo-[inositol-2-3H(N)] hexakisphosphate in rats. The radioactivity was measured in urine, feces, blood, gastrointestinal tract contents and various organs and tissues at 1 and 24 h after intragastric administration. Of the total radioactivity, 79.0 +/- 10.0% was absorbed and at least 26.6% was degraded during the 24-h period following ingestion. The absorption was rapid; 11.0 +/- 2.6% of the radioactivity was detected in the wall of the stomach (4.4 +/- 3.7%) and upper small intestine (6.6 +/- 1.9%), 6.5 +/- 2.6% in the skeletal muscle and 4.0 +/- 1.5% in the skin after 1 h. Much of the radioactivity after 24 h was in the liver (4.0 +/- 0.9%), kidneys (2.2 +/- 1.1%), muscle (18.1 +/- 3.4%) and skin (10.1 +/- 3.3%). Analysis of plasma and urine demonstrated that most of the radioactivity was due to myo-inositol and small amounts of inositol monophosphate (InsP1). Gastric epithelial cells, however, contained inositol and various inositol phosphates (InsP1-6). Our data suggest that soluble InsP6 when administered in drinking water is rapidly absorbed through the stomach and upper small intestine, becomes quickly dephosphorylated within the mucosal cells and is distributed to various organs as inositol and InsP1.

Animals↗

Antitumor activity of phytic acid (inositol hexaphosphate) in murine transplanted and metastatic fibrosarcoma, a pilot study.

We have previously reported that phytic acid (inositol hexaphosphate or InsP6), a natural constituent of cereal diet, when administered in drinking water exerts a consistent antitumor effect on experimental colon cancer in vivo. The objective of this study was to determine whether InsP6 has similar anti-neoplastic effect on other tumor models, such as murine fibrosarcoma. We report that intraperitoneal injection of InsP6 reduces growth of subcutaneously transplanted fibrosarcoma (FSA-1) in mice, prolongs survival of tumor-bearing mice and reduces the number of pulmonary metastases. Since InsP6 is a common constituent of our diet and has very little or no toxic effects, in addition to being chemopreventive, it could have potential use in therapy of cancer as well.

Animals↗