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Biomedical subjects

L M Ellis

Publications and source records attributed to L M Ellis.

At least 91 records · Page 5Linked to original sources

Gallbladder cancer and trocar site recurrences.

BACKGROUND: Critics of laparoscopic surgery cite an increased incidence of tumor recurrence at the trocar sites following laparoscopic cholecystectomy in patients incidentally found to have carcinoma of the gallbladder. The purpose of this review was to determine if laparoscopic cholecystectomy performed in patients with gallbladder cancer results in an increased incidence of abdominal wall recurrences. METHODS: The charts of all patients with gallbladder cancer registered at the University of Texas M. D. Anderson Cancer Center from January 1991 through April 1996 were retrospectively reviewed. Data were collected on initial and subsequent surgical procedures, tumor grade and histology, T stage, adjuvant therapy, and survival. These data were analyzed with regard to abdominal wall recurrences and outcome. RESULTS: Ninety-three patients with gallbladder cancer were seen during this period; 79 patients with complete follow-up information comprised the study population. Comparison of the incidence of abdominal wall recurrences among the categories of surgical procedure (laparoscopic versus open versus laparoscopic converted to open) did not reveal any statistically significant differences. Overall 5-year survival was 10%. CONCLUSIONS: Gallbladder cancer is an aggressive malignancy with few long-term survivors. In addition, these data show that the incidence of abdominal wall implantation is not increased with laparoscopic surgery but is more likely a manifestation of the aggressive nature of this tumor.

Abdominal Muscles↗

Regulation of vascular endothelial growth factor expression in human colon carcinoma cells by activity of src kinase.

BACKGROUND: The c-src protooncogene encodes a protein tyrosine kinase, pp60c-src, that is a mediator in many signal transduction pathways. One pathway in which pp60c-src protein tyrosine kinase activity is implicated involves regulation of vascular endothelial growth factor (VEGF), an angiogenic factor important to neovascularization of growing tumors. Recently we demonstrated that decreased activity of pp60c-src in colon tumor cells contributes to decreased expression of VEGF. This study examined the relationship between pp60c-src activation, cell density, and VEGF production in a colon tumor cell line. METHODS: Parental HT-29 colon adenocarcinoma cells and stable subclones created by transfection with c-src antisense and sense (control) expression vectors were plated under sparse (2 x 10(4) cells/cm2) and confluent (20 x 10(4) cells/cm2) conditions and grown for 36 hours. Protein and RNA were extracted from cells to determine pp60c-src levels, c-Src tyrosine kinase activity, and VEGF mRNA expression. RESULTS: The pp60c-src kinase activity of HT-29 cells and control sense-transfected clones grown under confluent conditions was increased threefold to fivefold compared with cells grown under sparse conditions. In contrast, the ability of confluent culture conditions to increase pp60c-src activity was blunted in antisense transfectants. By regression analysis, VEGF expression was found to vary directly with pp60c-src levels (r2 = 0.886). CONCLUSIONS: Cell density contributes to the regulation of c-src kinase activity and VEGF expression in HT-29 cells. When the steady-state level of pp60c-src is reduced in antisense transfectants, not only is the steady-state level of VEGF reduced, but the ability of confluence to stimulate pp60c-src activity and VEGF production is too. These data suggest that c-src may be an intermediary of both constitutive and inducible pathways for VEGF production in colon tumor cells.

Adenocarcinoma↗

Regulation of vascular endothelial growth factor expression in human colon carcinoma cells by cell density.

To determine the effect of cell density on vascular endothelial growth factor (VEGF) expression and the mechanism of this effect, four human colon cancer cell lines were grown as sparse or confluent monolayers or as spheroids. VEGF mRNA increased > 2-fold in cells grown as confluent monolayers or spheroids compared with cells grown as sparse monolayers. Semiquantitative reverse transcription-PCR demonstrated a 2-fold increase in the larger VEGF mRNA isoform (189 bp) in confluent cells. Sparse cells grown in conditioned medium from confluent cells demonstrated a > 2-fold increase in VEGF mRNA. These data suggest that VEGF expression may be regulated by an unidentified soluble factor.

Base Sequence↗

Platelet-derived endothelial cell growth factor in human colon cancer angiogenesis: role of infiltrating cells.

BACKGROUND: Development of new blood vessels is essential for tumor growth and metastasis and depends on the production of angiogenic factors by tumor and/or infiltrating cells. We previously showed that vascular endothelial growth factor (VEGF) expression and vessel count correlate with metastasis in human colon cancer. Although most tumors with high vessel counts express high levels of VEGF, some do not. Recently, platelet-derived endothelial cell growth factor (PD-ECGF), another potent angiogenic factor, has been reported to be expressed in colon cancer. PURPOSE: In this study, we examined the role of PD-ECGF in colon cancer angiogenesis and whether PD-ECGF is derived from the tumor or infiltrating cells. METHODS: Immunostaining for PD-ECGF was performed on 96 colon cancer specimens, some of which were previously stained for VEGF and factor VIII, a marker that is specific for endothelial cells. Double staining was done by using antibodies to PD-ECGF and to CD68 (macrophage specific) or CD3 (lymphocyte specific) to confirm which infiltrating cells produce PD-ECGF. Northern blot analysis for PD-ECGF messenger RNA (mRNA) was performed on four colon cancer specimens and corresponding normal colon mucosae (same patients) and four human colon cancer cell lines (KM12SM, SW620, HT29, and NCI-H508) to determine whether colon cancer epithelium expresses PD-ECGF. RESULTS: Immunohistochemical analysis demonstrated that PD-ECGF was expressed in infiltrating cells in most of the colon cancer specimens (80 [83%] of 96) but rarely in tumor epithelium (five [5%] of 96). Double staining demonstrated that infiltrating cells staining positive for both PD-ECGF and CD68 were more predominant than those staining positive for both PD-ECGF and CD3. The intensity of staining for PD-ECGF in infiltrating cells correlated with vessel counts (Spearman's rank correlation coefficient (R) = .29; P = .004), but did not correlate with the intensity of VEGF staining (R = .176, P = .086) or metastasis (Mann-Whitney U test, P = .253). PD-ECGF staining intensity was higher in specimens with a high vessel count (> 50 at high magnification) and low VEGF-staining intensity (< or = 2+) than in specimens with a high vessel count (again, > 50) and high VEGF-staining intensity (3+). Northern blot analysis revealed that colon cancer specimens and normal mucosae expressed relatively high levels of PD-ECGF mRNA, whereas PD-ECGF mRNA transcripts were not detectable in colon cancer cell lines. CONCLUSIONS AND IMPLICATIONS: PD-ECGF expression in human colon cancer specimens is associated with vessel count and may be responsible for tumor vascularity in those tumors with low VEGF expression. Infiltrating cells expressing PD-ECGF may contribute to angiogenesis, thus providing an additional mechanism for tumor neovascularization.

Blotting, Northern↗

Down-regulation of vascular endothelial growth factor in human colon carcinoma cell lines by antisense transfection decreases endothelial cell proliferation.

BACKGROUND: Vascular endothelial growth factor (VEGF) is a potent paracrine angiogenic factor implicated in human colon cancer angiogenesis. This study determined whether regulation of VEGF expression by human colon cancer cell lines affects endothelial cell proliferation in an in vitro model of angiogenesis. METHODS: Human colon carcinoma cell lines were screened for VEGF mRNA expression. SW480 cells (low VEGF expresser) were transfected with the VEGF sense (VS) vector, and SW620 cells (high VEGF expresser) were transfected with the VEGF antisense (VAS) vector. Cells were transfected with the vector alone as control. Endothelial cells were grown in conditioned, serum-free medium produced from experimental cells, and proliferation was determined. RESULTS: SW480-VS transfectants exhibited a sixfold increase in VEGF secretion. SW620-VAS transfectants exhibited a 50% reduction in VEGF secretion. Endothelial cells grown in conditioned medium from SW480-VS cells exhibited a 1.5- to 2-fold increase in proliferation. Addition of conditioned medium from SW620-VAS cells resulted in a 25% to 50% decrease in endothelial cell proliferation. CONCLUSIONS: VEGF production by human colon cancer cells regulates endothelial cell proliferation. Antisense VEGF transfection can down-regulate VEGF secretion and biologic activity. Therapies to decrease VEGF expression may be a means of inhibiting angiogenesis in primary and metastatic colon cancer.

Alternative Splicing↗

Progressive upregulation of metastasis-related genes in human colon cancer cells implanted into the cecum of nude mice.

We determined whether the upregulation of several metastasis-related genes in human colon carcinoma (HCC) cells implanted into the cecal wall of nude mice precedes HCC invasion of the muscle layer and subserosa and, ultimately, distant metastasis. HCC KM12SM cells were implanted into the subcutis (ectopic) or cecal wall (orthotopic). At weekly intervals for up to 6 weeks, cecectomy and resection of SC tumors were performed on different groups of mice. Survival and metastasis were assessed at 13 weeks. During the first 2 weeks after orthotopic implantation, the HCC cells grew progressively in the mucosa and submucosal layers of the cecum. By the third week, the cells invaded the muscularis propria and then the serosa. All mice undergoing cecectomy at weeks 1 and 2 were cured, whereas those undergoing cecectomy at later weeks were not. In situ hybridization analysis for expression of several metastasis-related genes-epidermal growth factor receptor (EGF-R), basic fibroblast growth factor (bFGF), collagenase type IV, and E-cadherin-revealed that the expression level of EGF-R, bFGF, and collagenase type IV in the early cecal tumors was low but increased just before invasion of the muscularis propria. At all times, the level of gene expression in the cecal tumors was higher than in the SC tumors. In contrast, the expression level of E-cadherin remained constant and did not differ between tumors in ectopic or orthotopic organs. The data suggest that the upregulation of some metastasis-related genes precedes tumor cell invasion and production of metastasis.

Animals↗

Multiparametric in situ mRNA hybridization analysis to predict disease recurrence in patients with colon carcinoma.

We examined the expression level of several genes that regulate different steps of metastasis in formalin-fixed, paraffin-embedded archival specimens of primary human colon carcinomas from patients with at least 5 years of follow-up. The expression of epidermal growth factor receptor, basic fibroblast growth factor, type IV collagenase, E-cadherin, and multidrug resistance (mdr-1) was examined by a colorimetric in situ mRNA hybridization technique concentrating on reactivity at the periphery of the neoplasms. The in situ hybridization technique revealed inter- and intratumor heterogeneity for expression of the metastasis-related genes. The expression of basic fibroblast growth factor, collagenase type IV, epidermal growth factor receptor, and mdr-1 mRNA was higher in Dukes's stage D than in Dukes' stage B tumors. Among the 22 Dukes' stage B neoplasms, 5 specimens exhibited a high expression level of epidermal growth factor receptor, basic fibroblast growth factor, and collagenase type IV. Clinical outcome data (5-year follow-up) revealed that all 5 patients with Dukes' stage B tumors developed distant metastasis (recurrent disease), whereas the other 17 patients with Dukes' stage B tumors expressing low levels of the metastasis-related genes were disease-free. Multivariate analysis identified high levels of expression of collagenase type IV and low levels of expression of E-cadherin as independent factors significantly associated with metastasis or recurrent disease. More specifically, metastatic or recurrent disease was associated with a high ratio (> 1.35) of expression of collagenase type IV to E-cadherin (specificity of 95%). Collectively, the data show that multiparametric in situ hybridization analysis for several metastasis-related genes may predict the metastatic potential, and hence the clinical outcome, of individual lymph-node-negative human colon cancers.

Carcinoma↗

Molecular determinants in the biology of liver metastasis.

A primary goal of cancer research is an increased understanding of the molecular mechanisms mediating the process of cancer metastasis. Analyses of colon cancer cells (the seeds) and the microenvironment (the soil) has increased our understanding of the biologic mechanisms mediating liver-specific metastasis. Insight into the molecular mechanisms regulating the pathobiology of cancer metastasis as well as a better understanding of the interaction between the metastatic cell and the host environment should produce a foundation for new therapeutic approaches. In this article we summarize experimental observations demonstrating the importance of specific factors that regulate various steps in the metastatic cascade. Furthermore, this article emphasizes the importance of the host organ's microenvironment and its role in liver metastasis formation. The production of metastases depends, in part, on the interaction of particular tumor cells with specific organ environments. Therefore, the successful metastatic cell must be viewed currently as a cell receptive to its environment. The analyses presented herein add important evidence to support the concept that cancer metastasis is not a random process; it is a highly regulated process that can be analyzed on the molecular level. To the clinician, it is readily apparent that by the time metastasis forms, most steps in the metastatic cascade have been completed. Therefore, therapy targeted to downregulate or interrupt the last stages of metastasis, proliferation and angiogenesis, should be the areas of greatest investigation in regards to treating established metastasis, whether they are microscopic or macroscopic.

Animals↗

Significance of vessel count and vascular endothelial growth factor and its receptor (KDR) in intestinal-type gastric cancer.

Angiogenesis is essential for tumor growth and metastasis and depends on the production of angiogenic factors by host and/or tumor cells. The role of angiogenesis and angiogenic factor expression in intestinal- and diffuse-type gastric cancer are undefined. Archival specimens of 51 intestinal-type and 38 diffuse-type human gastric carcinomas were examined for tumor vessel counts, angiogenic factor expression, and the presence or absence of angiogenic factor receptors on tumor endothelium using antibodies against vascular endothelial growth factor (VEGF) and its receptors (KDR and flt-1), basic fibroblast growth factor (bFGF) and its receptors (bek and flg), and factor VIII (endothelial cells). Vessel count and VEGF and bFGF expression were higher in intestinal-type than in diffuse-type gastric cancers (P = 0.01, P < 0.001, and P < 0.001, respectively). Similarly, vessel count and VEGF expression were higher in patients with liver metastasis than in patients with peritoneal dissemination (P = 0.003 and P = 0.01, respectively). Vessel count correlated with VEGF expression and the presence of endothelial KDR in intestinal-type gastric cancer (P = 0.003 and P = 0.02, respectively) but not diffuse-type gastric cancer. Vessel count, VEGF expression, and presence of endothelial KDR increased with increasing stage of disease in intestinal-type gastric cancer but not diffuse-type gastric cancer. The expression of bFGF and its receptors did not correlate with vessel count in either cancer type. These findings suggest that the pattern of metastasis in intestinal-type gastric cancer is angiogenesis dependent. The correlation of VEGF expression and its endothelial receptor with vessel count and stage of disease suggests that VEGF is at least one of the factors responsible for the induction of angiogenesis in intestinal-type gastric cancer.

Adult↗

Expression of vascular endothelial growth factor and its receptor, KDR, correlates with vascularity, metastasis, and proliferation of human colon cancer.

We studied the correlation between expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and their receptors with vascularity, metastasis, and proliferative index of human colon cancers. Immunohistochemical analyses using antibodies against VEGF, bFGF, their receptors (KDR, flt-1, bek, and flg), factor VIII, and proliferating cell nuclear antigen were carried out on archival specimens of 52 human colon carcinomas and 10 adenomas. Vessels were quantitated by light microscopy (x200), and the intensity of staining for VEGF and bFGF was assessed on a scale of 0-3+. The presence or absence of immunostaining for KDR, flt-1, bek, and flg was evaluated in endothelial cells, and proliferation was determined by counting the number of proliferating cell nuclear antigen-positive cells per 500 tumor cells. Expression of VEGF and KDR was higher in metastatic than in nonmetastatic neoplasms and directly correlated with the extent of neovascularization and the degree of proliferation, whereas expression of bFGF, flt-1, bek, and flg did not differ among tumor types. Vessel counts were greater in metastatic tumors than in nonmetastatic tumors. These findings support the hypothesis that VEGF is an important angiogenic factor in primary and metastatic human colon cancer. VEGF expression and vessel counts may aid in predicting patients at risk for metastasis from colon cancer.

Adenoma↗

Gastrointestinal leiomyosarcoma metastatic to the liver. Durable tumor regression by hepatic chemoembolization infusion with cisplatin and vinblastine.

BACKGROUND: Gastrointestinal leiomyosarcoma metastatic to the liver is considered most resistant to any combination of systemic chemotherapy containing doxorubicin and/or ifosphamide. METHODS: Fourteen patients with gastrointestinal leiomyosarcoma metastatic to the liver were treated with hepatic chemoembolization infusion consisting of polyvinyl alcohol sponge particles mixed with cisplatin powder (150 mg) followed by an intrahepatic arterial infusion of vinblastine (10 mg/m2). RESULTS: Ten major (> 50% regression) tumor responses were observed (70%) in patients lasting from 8 to 31+ months (median, 12 months) after an average of two hepatic chemoembolization procedures, usually 4 weeks apart. Transient side effects included right upper quadrant pain requiring narcotics, significant hepatic enzyme elevation, particularly of lactic dehydrogenase with a minimal increase in bilirubin, paralytic ileus requiring nasogastric suction up to 72 hours, urinary electrolyte losses (potassium+, magnesium++, sodium+) requiring supplements, and occasionally mild but transient leukopenia and thrombocytopenia. CONCLUSIONS: Hepatic chemoembolization infusion appears to induce a high rate of durable tumor response in patients with notoriously chemoresistant gastrointestinal leiomyosarcoma metastatic to the liver.

Adult↗

In situ mRNA hybridization technique for analysis of metastasis-related genes in human colon carcinoma cells.

The purpose of this study was to determine whether the expression level of several genes that regulate different steps of the metastatic process correlates with the metastatic potential of human colon carcinoma cells. The mRNA expression level for epidermal growth factor receptor (growth), basic fibroblast growth factor and interleukin-8 (angiogenesis), type IV collagenase (invasion), E-cadherin and carcinoembryonic antigen (adhesion), and the multidrug resistance gene mdr-1 (drug resistance) in the human KM12 colon carcinoma cell lines and clones with different metastatic potential was measured by Northern blot analysis and by in situ hybridization technique. Highly metastatic KM12SM and KM1214 cells growing in culture uniformly expressed high levels of epidermal growth factor receptor, basic fibroblast growth factor, and carcinoembryonic antigen mRNA, whereas cultures of low metastatic KM12C, clone 1, clone 3, and clone 6 cells displayed heterogeneous patterns of expression. KM12C (low metastatic) and KM12SM (highly metastatic) cells were implanted into the subcutis (ectopic) or the wall of the cecum (orthotopic) of nude mice. The mRNA expression level for epidermal growth factor receptor, basic fibroblast growth factor, interleukin-8, type IV collagenase, carcinoembryonic antigen, and mdr-1 was increased in the cecal wall tumors as compared with subcutaneous tumors or in vitro cultures. These data demonstrate a direct correlation between constitutive and inducible expression of several metastasis-related genes and the metastatic potential of human colon carcinoma cells.

Adenocarcinoma↗

Serum levels of transforming growth factor alpha in gastrointestinal cancer patients.

Transforming growth factor alpha (TGF alpha), a polypeptide growth-stimulating factor, has been implicated to play a role in the progression of gastrointestinal (GI) cancer. It has been suggested that TGF alpha expression in tumors or TGF alpha in the biological fluids of cancer patients may have tumor marker value. The serum levels of TGF alpha in GI cancer patients have not been reported. In this study, the serum TGF alpha levels of 100 GI cancer patients, as well as 74 healthy individuals, were determined by a TGF alpha-specific RIA kit. All of the cancer patient sera and 67% of the normal sera had detectable levels of TGF alpha. The TGF alpha concentrations in GI cancer patients ranged from 119 to 760 pg/ml, with a mean value of 269 +/- 102 pg/ml. Fifty normal individuals had detectable levels of TGF alpha, and their levels ranged from 120 to 207 pg/ml, with a mean value of 147 +/- 18 pg/ml. Differences in serum TGF alpha concentration between cancer patients and healthy individuals were found to be statistically significant, as evaluated by Mann-Whitney and Student's t tests. Serum TGF alpha levels were found to be significantly elevated in all disease stages of gastric, pancreas, colon, and rectal cancers, and only in the late stages of esophageal cancer. Serum carcinoembryonic antigen levels were significantly elevated only in the late stages of these diseases. The potential of serum TGF alpha as a tumor marker for GI malignancy, therefore, warrants further investigation.

Adult↗

Multiparametric in situ messenger RNA hybridization analysis to detect metastasis-related genes in surgical specimens of human colon carcinomas.

We examined the expression of several genes that regulate different steps of metastasis in surgical specimens of human colon carcinomas. The expression of epidermal growth factor receptor (growth), basic fibroblast growth factor [(bFGF), angiogenesis], type IV collagenase (invasion), E-cadherin (adhesion), and multidrug-resistant (mdr)-1 (drug resistance) mRNA was examined using an in situ mRNA hybridization (ISH) technique and Northern blot analysis. Dukes' stage C and D tumors exhibited a higher level of expression (P <0.05) for bFGF, type IV collagenase, and mdr-1 mRNA than Dukes' stage B tumors. The expression level of epidermal growth factor receptor and E-cadherin did not correlate with the stage of the disease. The ISH technique revealed intertumoral heterogeneity for expression of several genes among Dukes' stage B neoplasms. In some Dukes' stage B tumors, we also found intratumoral heterogeneous staining for bFGF and type IV collagenase, with the highest expression level at their invasive edge. In Dukes' stage C and D tumors, the expression of these genes was more uniform. These results recommend the suitability of the multiparametric ISH analysis for metastasis-related genes to identify individual colon cancers with metastatic potential.

Blotting, Northern↗