Warner Alpízar-Alpízar

Association of interleukin-1B and interleukin-1RN polymorphisms with gastric cancer in a high-risk population of Costa Rica.

Several risk factors have been associated with gastric cancer, among them Helicobacter pylori infection. This bacterium yields inflammation, the degree of which depends on the bacterial strain and the severity of the host response. The inflammatory response involves a complex cytokine network. Recently, polymorphisms of the genes coding for interleukin-1β (IL-1B), interleukin-1Ra (ILRN) and interleukin-10 have been associated with an increased risk of gastric cancer. In order to determine the association of the IL-1B, IL-1RN and IL-10 polymorphisms with gastric cancer in a high-risk Costa Rican population, we analysed purified DNA of 58 gastric cancer patients, 99 controls and 41 patients classified as group I or II, according to the Japanese classification. Genotyping was carried out by PCR, PCR-RFLP and pyrosequencing analysis. We did not find any association of the IL-1B-31, IL-1B-511 and IL-10 polymorphisms with the risk for developing gastric cancer in the studied population. Carriers of the IL-1B+3954T/– had an increased risk for developing gastric cancer (OR 3.7; 95%CI: 1.34–10.2). Also we found an increased risk for developing gastric cancer for allele 2 heterozygotes of the IL-1RN (OR 2.94; 95%CI: 1.09–7.93). This is the first time that IL-1B+3954 has been associated with gastric cancer. This is one of the first studies trying to describe the role played by IL-1B, IL-1RN and IL-10 genetic polymorphisms in gastric cancer in one of the highest risk American countries. Further investigation on American countries is needed.

Neutrophil gelatinase-associated lipocalin (NGAL/Lcn2) is upregulated in gastric mucosa infected with Helicobacter pylori.

Helicobacter pylori infection is one of the most significant risk factors for gastric cancer. The infection is established early in life and persists lifelong leading to a sustained chronic inflammation. Iron is essential for most living organisms. Bacteria use several mechanisms to acquire iron from their hosts, including the synthesis of the potent iron chelators known as siderophores. Hosts cells may express the siderophore-binding protein neutrophil gelatinase-associated lipocalin (NGAL/lipocalin-2 (Lcn2)) in response to infection, thus preventing bacterial iron uptake. We have characterized here the pattern of expression of NGAL/Lcn2 in gastric mucosa (45 non-neoplastic and 38 neoplastic tissue samples) and explored the connection between NGAL/Lcn2 expression and H. pylori infection. Immunohistochemical analysis showed high NGAL/Lcn2 expression in normal and gastritis-affected mucosa compared to low expression in intestinal metaplasia, dysplasia, and gastric cancer. In normal and gastritis-affected mucosa (n = 36 tissue samples), NGAL/Lcn2 was more frequently seen in epithelial cells located at the neck and base of the glands in H. pylori-positive cases than in similar epithelial cells of noninfected cases (Fisher’s exact test, p = 0.04). In conclusion, the high expression of NGAL/Lcn2 in normal and gastritis-affected mucosa infected with H. pylori suggests that NGAL/Lcn2 is upregulated locally in response to this bacterial infection. It is discussed whether this may have a causal relation to the development of gastric cancer.

Urokinase plasminogen activator receptor on invasive cancer cells: a prognostic factor in distal gastric adenocarcinoma.

Gastric cancer is the second cancer causing death worldwide. The five‐year survival for this malignancy is below 25% and few parameters have shown an impact on the prognosis of the disease. The receptor for urokinase plasminogen activator (uPAR) is involved in extracellular matrix degradation by mediating cell surface associated plasminogen activation, and its presence on gastric cancer cells is linked to micrometastasis and poor prognosis. Using immunohistochemistry, the prognostic significance of uPAR was evaluated in tissue samples from a retrospective series of 95 gastric cancer patients. uPAR was expressed by neoplastic cells, macrophages, myofibroblasts and neutrophils in both intestinal and diffuse subtypes. No association was demonstrated between the expression of uPAR on cancer cells and histological subtype (p = 0.64) or TNM stage (p = 0.75). Univariate analysis revealed a significant association between the expression of uPAR on tumor cells in the peripheral invasion zone and overall survival of gastric cancer patients (HR = 2.16; 95% CI: 1.13–4.14; p = 0.02). Multivariate analysis showed that uPAR immunoreactivity in cancer cells at the invasive front is an independent prognostic factor for overall survival in gastric cancer (HR = 2.39; 95% CI: 1.22–4.69; p = 0.011). In consequence, scoring of uPAR‐positive cancer cells may be a direct measure for the invasive potential of gastric adenocarcinomas.

Urokinase plasminogen activator receptor is expressed in invasive cells in gastric carcinomas from high- and low-risk countries

Gastric cancer is the second cancer causing death worldwide. Both incidence and mortality rates vary according to geographical regions. The receptor for urokinase plasminogen activator (uPAR) is involved in extracellular matrix degradation by mediating cell surface associated plasminogen activation, and its presence on gastric cancer cells is linked to micro‐metastasis and poor prognosis. Immunohistochemical analyses of a set of 44 gastric cancer lesions from Costa Rica showed expression of uPAR in cancer cells in both intestinal subtype (14 of 27) and diffuse subtype (10 of 17). We compared the expression pattern of uPAR in gastric cancers from a high‐risk country (Costa Rica) with a low‐risk country (Norway). We found uPAR on gastric cancer cells in 24 of 44 cases (54%) from Costa Rica and in 13 of 23 cases (56%) from Norway. uPAR was seen in macrophages and neutrophils in all cases. We also examined the nonneoplastic mucosa and found that uPAR was more frequently seen in epithelial cells located at the luminal edge of the crypts in cases with Helicobacter pylori infection than in similar epithelial cells in noninfected mucosa (p = 0.033; χ2 = 4.54). In conclusion, the expression of uPAR in cancer cells in more than half of the gastric cancer cases suggests that their uPAR‐positivity do not contribute to explain the different mortality rates between the 2 countries, however, the actual prevalence of uPAR‐positive cancer cells in the gastric cancers may still provide prognostic information.

Prognosis in adenocarcinomas of lower oesophagus, gastro-oesophageal junction and cardia evaluated by uPAR-immunohistochemistry.

Adenocarcinomas of lower oesophagus, gastro‐oesophageal junction and cardia in humans are highly invasive tumours with poor prognosis. The localisation of urokinase‐type plasminogen activator receptor (uPAR) was determined in 66 patients; 60 with adenocarcinomas and six cases with Barretts oesophagus. uPAR was expressed in nearly all cases of invasive adenocarcinomas by populations of cancer cells, macrophages and myofibroblasts at both the invasion front and the tumour core. In areas with high‐grade dysplasia or with Barretts metaplasia adjacent to the tumour tissue, no uPAR‐immunoreactivity was found. High local expression of uPAR, therefore, appears to be a characteristic marker for invasive behaviour in this tumour, suggesting that uPARs contribution to matrix degradation during invasive growth is a late event in carcinogenesis. Using a scoring system for semiquantitative estimation of uPAR‐positivity on immmunohistochemically stained specimens, a significant association was found between poor overall survival and high uPAR‐score for cancer cells in the tumour core and for macrophages peripherally at the tumour invasion zone. In multivariate analysis, these two uPAR‐scores were confirmed as highly significant prognostic parameters independent of Tumour, Node, Metastasis (TNM)‐stage and World Health Organization (WHO) classification. The proteolytic action of these malignant and nonmalignant accessory cells thus seemed to follow two main patterns: one dominated by uPAR positive cancer cells and one by uPAR‐positive macrophages. Scoring of uPAR‐positivity might be a useful parameter for onset of invasion and prognosis in these adenocarcinomas.

The Urokinase Receptor Homolog Haldisin Is a Novel Differentiation Marker of Stratum Granulosum in Squamous Epithelia

Several members of the Ly-6/uPAR (LU)-protein domain family are differentially expressed in human squamous epithelia. In some cases, they even play important roles in maintaining skin homeostasis, as exemplified by the secreted single domain member, SLURP-1, the deficiency of which is associated with the development of palmoplantar hyperkeratosis in the congenital skin disorder Mal de Meleda. In the present study, we have characterized a new member of the LU-protein domain family, which we find to be predominantly expressed in the stratum granulosum of human skin, thus resembling the expression of SLURP-1. In accordance with its expression pattern, we denote this protein product, which is encoded by the LYPD5 gene, as Haldisin (human antigen with LU-domains expressed in skin). Two of the five human glycolipid-anchored membrane proteins with multiple LU-domains characterized so far are predominantly confined to squamous epithelia (i.e., C4.4A), to stratum spinosum, and Haldisin to stratum granulosum under normal homeostatic conditions. Whether Haldisin is a prognostic biomarker for certain epithelial malignancies, like C4.4A and SLURP-1, remains to be explored.

Tissue inhibitor of matrix metalloproteinase‐1 expression in colorectal cancer liver metastases is associated with vascular structures

Metastatic growth by colorectal cancer cells in the liver requires the ability of the cancer cells to interact with the new microenvironment. This interaction results in three histological growth patterns of liver metastases: desmoplastic, pushing, and replacement. In primary colorectal cancer several proteases, involved in the degradation of extracellular matrix components, are up‐regulated. In liver metastases, their expression is growth pattern dependent. Tissue inhibitor of matrix metalloproteinase‐1 (TIMP‐1) is a strong prognostic marker in plasma from colorectal cancer patients, with significant higher levels in patients with metastatic disease. We therefore wanted to determine the expression pattern of TIMP‐1 in primary colorectal cancers and their matching liver metastases. TIMP‐1 mRNA was primarily seen in α‐smooth‐muscle actin (α‐SMA)‐positive cells. In all primary tumors and liver metastases with desmoplastic growth pattern, TIMP‐1 mRNA was primarily found in α‐SMA‐positive myofibroblasts located at the invasive front. Some α‐SMA‐positive cells with TIMP‐1 mRNA were located adjacent to CD34‐positive endothelial cells, identifying them as pericytes. This indicates that TIMP‐1 in primary tumors and liver metastases with desmoplastic growth pattern has dual functions; being an MMP‐inhibitor at the cancer periphery and involved in tumor‐induced angiogenesis in the pericytes. In the liver metastases with pushing or replacement growth patterns, TIMP‐1 was primarily expressed by activated hepatic stellate cells at the metastasis/liver parenchyma interface. These cells were located adjacent to CD34‐positive endothelial cells, suggesting a function in tumor‐induced angiogenesis. We therefore conclude that TIMP‐1 expression is growth pattern dependent in colorectal cancer liver metastases.

Tissue Inhibitor of Metalloproteinase-1 Is Confined to Tumor-Associated Myofibroblasts and Is Increased With Progression in Gastric Adenocarcinoma

The tissue inhibitor of metalloproteinase-1 (TIMP-1) inhibits the extracellular matrix–degrading activity of several matrix metalloproteinases, thereby regulating cancer cell invasion and metastasis. Studies describing the expression pattern and cellular localization of TIMP-1 in gastric cancer are, however, highly discordant. We addressed these inconsistencies by performing immunohistochemistry and in situ hybridization analyses in a set of 49 gastric cancer lesions to reexamine the TIMP-1 localization. In addition, we correlated these findings to clinicopathological parameters. We show that strong expression of TIMP-1 protein and mRNA was observed in a subpopulation of stromal fibroblast-like cells at the periphery of the cancer lesions. In a few cases, a small fraction of cancer cells showed weak expression of TIMP-1 protein and mRNA. The stromal TIMP-1-expressing cells were mainly tumor-associated myofibroblasts. In the normal-appearing mucosa, scattered TIMP-1 protein was only found in chromogranin A positive cells. TIMP-1-positive myofibroblasts at the invasive front of the tumors were more frequently seen in intestinal than in diffuse histological subtype cases (p=0.009). A significant trend to a higher number of cases showing TIMP-1 staining in myofibroblasts with increasing tumor, node, metastasis (TNM) stage was also revealed (p=0.041). In conclusion, tumor-associated myofibroblasts are the main source of increased TIMP-1 expression in gastric cancer.

Inflammation and uPAR-Expression in Colorectal Liver Metastases in Relation to Growth Pattern and Neo-adjuvant Therapy.

Proteolytic activity and inflammation in the tumour microenvironment affects cancer progression. In colorectal cancer (CRC) liver metastases it has been observed that three different immune profiles are present, as well as proteolytic activity, determined by the expression of urokinase-type plasminogen activator (uPAR).The main objectives of this study were to investigate uPAR expression and the density of macrophages (CD68) and T cells (CD3) as markers of inflammation in resected CRC liver metastases, where patients were neo-adjuvantly treated with chemotherapy with or without the angiogenesis inhibitor bevacizumab. Chemonaive patients served as a control group. The markers were correlated to growth patterns (GP) of liver metastases, i.e. desmoplastic, pushing and replacement GP. It was hypothesised that differences in proteolysis and inflammation could reflect tumour specific growth and therapy related changes in the tumour microenvironment. In chemonaive patients, a significantly higher level of uPAR was observed in desmoplastic liver metastases in comparison to pushing GP (p = 0.01) or replacement GP (p = 0.03). A significantly higher density of CD68 was observed in liver metastases with replacement GP in comparison to those with pushing GP (p = 0.01). In liver metastases from chemo treated patients, CD68 density was significantly higher in desmoplastic GP in comparison to pushing GP (p = 0.03). In chemo and bevacizumab treated patients only a significant lower CD3 expression was observed in liver metastases with a mixed GP than in those with desmoplastic (p = 0.01) or pushing GP (p = 0.05). Expression of uPAR and the density of macrophages at the tumour margin of liver metastasis differ between GP in the untreated patients. A higher density of T cells was observed in the bevacizumab treated patients, when desmoplastic and pushing metastases were compared to liver metastases with a mix of the GP respectively, however no specific correlations between the immune markers of macrophages and T cells or GP of liver metastases could be demonstrated.

Priming the seed: Helicobacter pylori alters epithelial cell invasiveness in early gastric carcinogenesis

Helicobacter pylori (H. pylori) infection is a well-established risk factor for the development of gastric cancer (GC), one of the most common and deadliest neoplasms worldwide. H. pylori infection induces chronic inflammation in the gastric mucosa that, in the absence of treatment, may progress through a series of steps to GC. GC is only one of several clinical outcomes associated with this bacterial infection, which may be at least partially attributed to the high genetic variability of H. pylori. The biological mechanisms underlying how and under what circumstances H. pylori alters normal physiological processes remain enigmatic. A key aspect of carcinogenesis is the acquisition of traits that equip preneoplastic cells with the ability to invade. Accumulating evidence implicates H. pylori in the manipulation of cellular and molecular programs that are crucial for conferring cells with invasive capabilities. We present here an overview of the main findings about the involvement of H. pylori in the acquisition of cell invasive behavior, specifically focusing on the epithelial-to-mesenchymal transition, changes in cell polarity, and deregulation of molecules that control extracellular matrix remodeling.