Prognosis and clinicopathologic features in patients with gastric stump cancer after curative surgery.

Background: Gastric stump ("remnant") cancer is the development of a malignancy related to previous gastric surgery. Prognosis in gastric stump cancer, compared with that in primary gastric cancer, is still controversial. Methods: From January 1988 to December 2012 at a single medical centre in Taiwan, 105 patients with gastric stump cancer, including 85 with previous peptic ulcer disease and 20 with previous gastric cancer, were analyzed for clinicopathologic characteristics and overall survival (os). Results: The 5-year os rates for patients with gastric stump cancer and with primary gastric cancer were 51.2% and 54.5% respectively (p = 0.035). Analysis of clinicopathologic characteristics indicated that, compared with patients having primary gastric cancer, those with gastric stump cancer had more lymph node metastasis (p < 0.001) and had been diagnosed at a more advanced stage (p = 0.047). Multivariate analysis with os as an endpoint showed that age [p = 0.015; hazard ratio (hr): 2.300; 95% confidence interval (ci): 1.173 to 4.509], tumour size (p = 0.037; hr: 1.700; 95% ci: 1.031 to 2.801), stromal reaction (p = 0.021; hr: 1.802; 95% ci: 1.094 to 2.969), and pathologic N category (p = 0.001; hr: 1.449; 95% ci: 1.161 to 1.807) were independent predictors in gastric stump cancer. The os rates for patients with gastric stump cancer who previously had gastric cancer or peptic ulcer disease were 72.9% and 50.0% respectively (p = 0.019). The Borrmann classification was more superficial (p = 0.005), lymph node metastases were fewer (p = 0.004), and staging was less advanced (p = 0.025) in patients with gastric stump cancer who previously had gastric cancer than in their counterparts who previously had peptic ulcer disease. Conclusions: Survival is poorer in patients with gastric stump cancer who previously had peptic ulcer disease than in those who previously had primary gastric cancer. Patients with gastric stump cancer who previously had gastric cancer and could receive curative gastrectomy tended to have a better prognosis because of a more superficial Borrmann classification. Regular follow-up in patients who have undergone gastric surgery is recommended for the early detection of gastric stump cancer.

Development of multiple complications in type 2 diabetes is associated with the increase of multiple markers of chronic inflammation.

Patients with type 2 diabetes (T2DM) are known at risk for developing cardiovascular disease (CVD), nephropathy, and cancer. We were interested to find out whether multiple markers associated with chronic inflammation are detectable in patients with T2DM and are increased in patients with T2DM who developed additional clinical complications. A sequence of multiple risk markers for atherogenesis, associated with chronic inflammation, was measured in patients with T2DM before and after the development of clinical complications. We found that multiple clinical complications frequently developed simultaneously in patients with T2DM. At the early stage of T2DM, only low levels and low percent elevations of multiple risk markers were detected. However, both the level and the percent elevation of these markers were found to increase with disease progression and the development of clinical complications. We believe that chronic inflammation not only contributes to the pathogenesis of T2DM but also continues to increase in T2DM patients who are developing additional clinical complications. It appears that these multiple markers are potentially useful not only for monitoring the progression of T2DM but also predicting the risk of developing macro- and microvascular disease, nephropathy, and cancer.

Evidence that involucrin, a marker for differentiation, is oxygen regulated in human squamous cell carcinomas.

The majority of hypoxic cells in squamous cell carcinomas of the head and neck and cervix express involucrin, a molecular marker for differentiation. This raises the question of whether involucrin is an oxygen-regulated protein and, if so, whether it could serve as an endogenous marker for tumour hypoxia. Consistent with oxygen regulation, involucrin protein was found to increase with increasing hypoxia in confluent cultures of moderately differentiated human SCC9 cells. Cells harvested at the point of confluence and exposed to graded concentrations of oxygen revealed a K(m) of approximately 15 mmHg for involucrin induction. This is similar to K(m)s for HIF-1alpha, CAIX and VEGF. Involucrin induction showed a steep dependence on pO(2) with a transition from minimum to maximum expression occurring over less than an order of magnitude change in pO(2). In contrast to SCC9 cells, involucrin was not induced by hypoxia in poorly differentiated SCC4 cells. It is concluded that involucrin is an oxygen-regulated protein, but that differentiation modulates its transcription status with respect to hypoxia induction.

Semiquantitative immunohistochemical analysis for hypoxia in human tumors.

OBJECTIVE: The goal of this study was to develop a semiquantitative scoring system for measuring hypoxia in human tumors by an immunohistochemical marker approach. METHODS AND MATERIALS: Eighteen patients diagnosed with squamous cell carcinoma of the uterine cervix or head and neck were infused intravenously with a solution of pimonidazole hydrochloride at a dose of 0.5 gm/m2. Twenty-four hours later, four biopsies on average from each tumor were fixed in formalin, processed into paraffin blocks, and sectioned. Tissue sections were immunostained for the presence of pimonidazole adducts. Microscopic images (x200) of immunostaining were captured and quantitated by standard image analysis. Images with known amounts of hypoxia spanning ranges of > 0% to 5%, > 5% to 15%, > 15% to 30%, and >30% were assigned scores of +1, +2, +3, and +4, respectively. Three observers then used this calibrated scoring system to analyze hypoxia in tumor sections in a blinded fashion. RESULTS: Excellent interobserver reproducibility was obtained with the calibrated, semiquantitative, immunohistochemical assay for hypoxia in squamous cell carcinomas. CONCLUSION: The calibrated, semiquantitative assay shows promise as an approach to simplifying the quantitation of human tumor hypoxia by immunohistochemical techniques.

Invasive oxygen measurements and pimonidazole labeling in human cervix carcinoma.

PURPOSE: This study was designed to compare tumor hypoxia assessed by invasive O2 sensitive electrodes and pimonidazole labeling in primary human cervix carcinomas. METHODS AND MATERIALS: Twenty-eight patients with primary cervix carcinomas (FIGO Stage Ib-IVa) were investigated. Both invasive pO2 measurements and pimonidazole labeling were obtained in all patients. Before treatment, patients were given pimonidazole as a single injection (0.5 g/m2 i.v.). Ten to 24 h later, oxygenation measurements were done by Eppendorf histography, and after this procedure biopsies were taken for pimonidazole-binding analysis. Tumor oxygen partial pressure (pO2) was evaluated as the median tumor pO2 and the fraction of pO2 values < or = 10 mmHg (HF10). Biopsies were formalin fixed and paraffin embedded, and hypoxia was detected by immunohistochemistry using monoclonal antibodies directed against reductively activated pimonidazole. Pimonidazole binding was evaluated by a semiquantitative scoring system. RESULTS: Both Eppendorf measurements and pimonidazole binding showed large intra-and intertumor variability. A comparison between pimonidazole binding expressed as the fraction of fields at the highest score and HF10 showed a trend for the most well-oxygenated tumors having a low fraction of fields; however, the correlation did not reach statistical significance (p = 0.43, r = 0.165; Spearman's rank correlation test). CONCLUSION: Hypoxia measured in human uterine cervix carcinomas is heterogeneously expressed both within and between tumors when assessed by either invasive pO2 measurements or pimonidazole binding. Despite a trend that tumors with high pO2 values expressed less pimonidazole binding, no correlation was seen between the two assays in this preliminary report.

A clinical study of hypoxia and metallothionein protein expression in squamous cell carcinomas.

The objective was to discover whether the oxygen-regulated protein, metallothionein, is expressed in the hypoxic cells of squamous cell carcinomas. Twenty patients with squamous cell carcinoma of the uterine cervix or head and neck were infused with a solution of the hypoxia marker, pimonidazole hydrochloride, at a dose of 0.5 g/m2. The following day, biopsies were collected, formalin fixed, paraffin embedded, and sectioned at 4 microm. Sections from each biopsy were immunostained for pimonidazole binding, metallothioneins I and II, involucrin, and proliferating cell nuclear antigen. A total of 84 biopsies were analyzed. Sixty-four of 84 biopsy sections contained hypoxia. Of the hypoxia-containing sections, 43 of 64 or 67% showed no microregional overlap between hypoxia and metallothionein; 7 of 64 showed overlap; and 14 of 64 showed a combination of overlap and no overlap. On a tumor-by-tumor basis, 5 of 7 head and neck and 7 of 13 cervix tumors showed no overlap between metallothionein and hypoxia at the microregional level. Ranges for the percentage of the area of hypoxia in head and neck (<0.9 to 17%) and cervix (<0.1 to 14%) tumors were similar. In the hypoxia-containing sections, immunostaining for involucrin, a molecular marker for differentiation, overlapped with that for hypoxia in 82% of the cases. The majority of hypoxic cells in squamous cell carcinomas do not express metallothionein protein, although metallothionein is induced by hypoxia in human tumor cells in vitro. Hypoxic cells in human tumors tend to be in regions immunostaining for involucrin, and it seems possible that differentiation of hypoxic cells in squamous cell carcinomas might affect metallothionein I and II expression.

Comparisons among pimonidazole binding, oxygen electrode measurements, and radiation response in C3H mouse tumors.

Pimonidazole binding was compared with oxygen electrode measurements and with measurements of the radiobiologically hypoxic fraction in C3H mammary tumors in which oxygenation was manipulated by means of subjecting tumor-bearing CDF1 mice to air breathing, carbogen breathing, oxygen breathing, hydralazine injection or tumor clamping. Hypoxia measured by pimonidazole binding could be correlated with both pO2 (r2 = 0.81) and radiobiologically hypoxic fraction (r2 = 0.85) in this system. The scope and limitation of pimonidazole as an immunohistochemical marker for tumor hypoxia is discussed.

Relationship of hypoxia to metallothionein expression in murine tumors.

PURPOSE: To investigate if metallothionein, an endogenous chemo- and radioprotectant, is expressed in hypoxic cells in mouse C3H mammary carcinomas and if that expression responds to acute changes in tumor hypoxia. METHODS AND MATERIALS: C3H mammary tumors were established in the hind legs of female CDF1 mice. The mice were then subjected to air breathing (chronic hypoxia), carbogen breathing (acute decrease in hypoxia), or hydralazine injection (acute increase in hypoxia). Ninety minutes after the start of the experiment, tumors were excised, fixed in formalin, and sectioned. Hypoxic cells and metallothionein-containing cells were quantitated by image analysis. Pimonidazole hydrochloride and an IgG1 mouse monoclonal antibody were used to detect hypoxia, and a mouse antimetallothionein monoclonal antibody (DAKO) was used to detect Type I and II metallothionein in sets of contiguous tissue sections. RESULTS: The distribution of immunostaining intensity for metallothionein was the same in all three groups-heavy in hypoxic cells and light in other regions of the tumors. The acute increase in hypoxia caused by hydralazine injection was accompanied by an increase in metallothionein expression (p = 0.04). Carbogen breathing largely eliminated pimonidazole binding, but metallothionein expression persisted in the tumors of carbogen-breathing mice. CONCLUSIONS: Hypoxic cells in C3H mammary carcinomas strongly express metallothionein. Metallothionein expression is responsive to acute increases in hypoxia brought about by hydralazine injection. The effectiveness of hydralazine in enhancing the activation of bioreductive cytotoxins might be offset by the increased expression of metallothionein. The persistence of metallothionein in tumors of carbogen-breathing mice might contribute to a residual radioresistance in the tumors.

Marking hypoxic cells for complement and cytotoxic T lymphocyte-mediated lysis: using pimonidazole.

Artificial antigens are created when 2-nitroimidazoles bind to hypoxic cells. These antigens have been used in the immunodetection of tumour hypoxia but they might also serve to stimulate immune lysis of hypoxic tumour cells by complement- and cell-mediated processes. In order to test this hypothesis, lymphocytes isolated from the spleens of C3H/HeN mice that had been immunised with pimonidazole-labelled 3152-PRO cells were subcultured and tested for their ability to lyse chromium-51 loaded, pimonidazole-labelled 3152-PRO cells in an in vitro assay. In a parallel study, commercially available, rabbit complement was tested for its ability to lyse pimonidazole-labelled V79-4 cells in the presence of monoclonal antibodies which recognise protein adducts of reductively activated pimonidazole. Complement-mediated cell lysis was measured by means of an MTT assay. Complement-mediated and cell-mediated lysis was observed at pimonidazole concentrations which, in themselves, do not produce cell killing.

Developmental regulation of the catalytic subunit of the apolipoprotein B mRNA editing enzyme (APOBEC-1) in human small intestine.

Apolipoprotein (apo) B mRNA editing is a site-specific cytidine deamination reaction responsible for the production of apoB-48 in mammalian small intestine. This process is mediated by an enzyme complex that includes the catalytic subunit, APOBEC-1. In the present study, it is shown that the developmental regulation of apoB mRNA editing in fetal human small intestine is closely mirrored by accumulation of APOBEC-1 mRNA. Similar results were obtained using Caco-2 cells, the data further suggesting that culture of these cells under conditions previously shown to promote differentiation produce an earlier and more marked induction of APOBEC-1 mRNA abundance. Complementary analysis of APOBEC-1 protein accumulation using immunocytochemical localization reveals its appearance to be temporally coordinated with the accumulation of APOBEC-1 mRNA and its distribution to be confined to villus-associated enterocytes. Previous studies demonstrated a close temporal association between the development of triglyceride synthesis and apoB mRNA editing in the rat liver and small intestine. Analysis of fatty acid CoA ligase, monoacylglycerol acyltransferase, and diacylglycerol acyltransferase activity in preparations of human liver and small intestine demonstrates activity of all three enzymes in the late first and early second trimester, suggesting that certain aspects of complex lipid biosynthesis in the human fetal small intestine and liver are regulated developmentally. The cues that modulate the post-transcriptional regulation of fetal human small intestinal apoB gene expression may thus include both temporal programming and events related to the emergence of lipid transport capability.

Characterization of choline metabolism and secretion by human placental trophoblasts in culture.

Choline is an essential nutrient for fetal development and may be utilized to form phospholipids such as phosphatidylcholine and sphingomyelin; to synthesize the neurotransmitter, acetylcholine; and to donate methyl groups after being oxidized to betaine. Since the majority of choline required for fetal growth must be transported by the placenta from the maternal circulation, we examined the ability of isolated human trophoblasts to metabolize choline and to release choline and its metabolites into culture medium. Cytotrophoblasts were isolated from normal, full-term human placentas and incubated with [14C]choline for 3 h; the cells were washed to remove extracellular radiolabel, and the changes in intracellular and medium choline pools were followed for an additional 24 h. During the incubation, choline rapidly reached steady state intracellularly and label was incorporated into betaine, phosphocholine, cytidylyldiphosphocholine, phosphatidylcholine, glycerophosphocholine, lysophosphatidylcholine, and sphingomyelin. All labeled choline metabolites in cells, except glycerophosphocholine, decreased at 6 and 27 h of incubation (3 and 24 h, respectively, after labeled choline was removed), and labeled metabolites appeared in media. By 24 h after labeled choline was removed, the major labeled metabolites in the media were choline (82%), betaine (11%), and glycerophosphocholine (5%). Small amounts of phosphatidylcholine (1%), and lysophosphatidylcholine (1%) were found. Acetylcholine was a very minor choline metabolite in these cells. When placental cells were incubated for 66 h after isolation, they formed syncytiotrophoblasts, which incorporated labeled choline into metabolites in a similar pattern to cytotrophoblasts. These data indicate that isolated trophoblast cells can metabolize choline to form all of its major metabolites and that several metabolites are released to the medium in significant amounts. Thus, our data suggest that the major metabolite supplied to the fetus may be choline, but that betaine and glycerophosphocholine may also be vehicles for transfer of choline equivalents from mother to fetus.

Antileukemic activity of Viva-Natural, a dietary seaweed extract, on Rauscher murine leukemia in comparison with anti-HIV agents, azidothymidine, dextran sulfate and pentosan polysulfate.

An antileukemic activity of partially purified polysaccharide of an edible seaweed. Viva-Natural, against Rauscher murine retrovirus-induced erythroleukemia has been demonstrated. This antileukemic effect is compared with standard anti-human immunodeficiency virus (HIV) agents, azidothymidine (AZT), dextran sulfate and pentosan polysulfate. Pretreatment with Viva-Natural, as an immunomodulator, on day 3 prior to the virus inoculation demonstrated definite prophylactic activity, while pretreatment with the other three anti-HIV agents showed no prophylactic activity. The replication of Rauscher virus in BALB/3T3 cell cultures accompanied by direct cytopathic effect (syncytia formation) was suppressed in the presence of Viva-Natural or the other anti-HIV agents in the culture medium. In spite of the antiviral potentials of the four agents in vitro, only Viva-Natural and AZT demonstrated therapeutic efficacy against Rauscher leukemia in mice.

Tropic effect of dexamethasone on goldfish melanocytoma cells: induction of calcium-dependent but protein synthesis-independent morphological changes.

Treatment of melanocytoma cells of goldfish origin with dexamethasone leads to rapid morphological changes, flattening of cell body and extension of dendrites. This effect is independent of protein synthesis but requires the presence of extracellular calcium, indicating that it is a "tropic effect" distinct from the typical "trophic effects" of steroid hormones that involve de novo protein synthesis.

Reversible dedifferentiation and redifferentiation of a melanized cell line from a goldfish tumor.

We reported previously the isolation of a melanized cell line that can undergo reversible dedifferentiation and redifferentiation. A heavily pigmented cell line, designated as P15, originally isolated by fish serum-induced melanization of some GEM 81 cells, cloned and serially passaged in fish serum medium, became noticeably less pigmented after several months in fetal calf serum medium and completely unpigmented after another year in the same medium. Addition of fish serum to the medium of this dedifferentiated cell line, designated P15D, induced pigmentation within a week. This re-induced pigmented cell line, designated as P15DI, became unpigmented when cultured in fetal calf serum medium for one month. We report here that the dedifferentiation of P15 occurs in two stages. One week after withdrawal of fish serum, the specific activity of tyrosinase of the culture dropped by approximately 70% and remained at this reduced level for at least one month. After one year, the specific activity of tyrosinase had dropped to a barely detectable level and the culture became completely unpigmented (P15D). Electron microscopic studies showed that the P15D cells have no melanosomes, probably no large vesicles for melanosome formation, but some dopa-positive trans-Golgi network (TGN). Addition of fish serum to the growth medium of P15 cultures led to a steady increase in the specific activity of tyrosinase, detectable after one day. There was also an increase in the amount of dopa-positive TGN within one day. Melanosomes first appeared after three days and became numerous after one week. Upon removal of fish serum, these re-induced cells (P15D1) underwent a rapid decrease in the specific activity of tyrosinase, reaching, after eight days, the basal level seen in P15D cells. We also report that a protein designated as p75 (Mr approximately 75,000), previously shown to be associated with melanosomes in two melanized cell types of goldfish origin, is present in all melanized cell lines, including P15 and P15DI but absent in unmelanized cell lines, including P15D.

Phosphorylation of the carotenoid droplet protein p57 by the catalytic subunit of cyclic adenosine monophosphate-dependent protein kinase and the effect of fluoride.

We have previously shown that the dispersion and aggregation of carotenoid droplets in goldfish xanthophores are regulated, respectively, by phosphorylation and dephosphorylation of a carotenoid droplet protein p57. There is a basal level of p57 phosphorylation of p57 in unstimulated cells, which is greatly stimulated by adrenocorticotropic hormone (ACTH) or cyclic adenosine monophosphate (cAMP) acting via cAMP-dependent protein kinase. We have also observed that, in permeabilized xanthophores, pigment dispersion can be induced when cAMP is replaced by fluoride. Since p57 has multiple phosphorylation sites, there is the question of whether all p57 phosphorylation is by cAMP-dependent protein kinase or whether phosphorylation by cAMP-independent protein kinase coupled with inhibition of phosphatase activity by fluoride can replace cAMP-dependent protein kinase and that the ability of fluoride to replace cAMP for pigment dispersion in permeabilized cells is probably due to activation of adenylcyclase. We also show that ACTH causes an approximately threefold increase in the level of cAMP in these cells.

Epinephrine-induced pigment aggregation in goldfish melanophoroma cells: apparent involvement of an unknown second messenger.

Using a goldfish-derived melanized cell line, we attempted to determine the identity of the signal transduction system/second messenger for epinephrine-induced aggregation of melanosomes in a goldfish cell line. The results show that the second messenger is unknown. It is not 1) influx of extracellular calcium, 2) release of intracellular stored calcium via the phosphoinositide pathway, 3) cGMP, or 4) decrease of cAMP. These results suggest that there is an unknown second messenger for this activity of epinephrine.

Colorectal cancer and schistosomiasis.

The risk of colorectal cancer is known to be increased in patients with long-standing schistosomal colitis. A retrospective review of clinical data and surgical specimens from 60 patients with schistosomal granulomatous disease of the large intestine but without carcinoma demonstrated that 36 of them had mild to severe grades of colonic epithelial dysplasia. This was either focal or diffuse in distribution and occurred in flat mucosa, in pseudopolyps, or in regenerating epithelium at the edges of ulcers. These dysplastic changes are regarded as the pathological basis for the malignant potential of schistosomal colitis, and they resemble the changes found in long-standing chronic ulcerative colitis.

Effect of levamisole on metabolism of phagocytic cells.

The effect of levamisole (LMS) on glucose metabolism was studied using a protozoan phagocytic model and human leukocytes. At concentrations of greater than 10 microgram/ml, LMS inhibited glucose metabolism in the protozoan phagocytic model. Glucose metabolism in both the phagocytic model and normal peripheral blood leukocytes was, however, minimally altered when exposed to levels of LMS of less than 10 microgram/ml. In contrast, myeloblasts from a child with leukemia seemed to have increased metabolic activity and 5 microgram/ml of LMS markedly reduced the glucose metabolism. These preliminary studies suggest that LMS can alter glucose metabolism of certain cells and that some malignant cells may be directly inhibited metabolically by LMS.