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Introduction Gastric signet ring cell carcinoma (GSRC) is a distinct entity among of other gastric cancer. With unknown etiopathology, their incidence is increasing and it presents a low sensitivity to chemotherapy. Aim Here, we studied the expression of the heparanase (HPA) in cancer tissues from GSRC patients and several cancer cell lines. HPA is an endo-β-D-glucuronidase, capable of cleaving the lateral chains of heparan sulfate on cell surfaces and the extracellular matrix at acidic pH. Apart from its well-characterized enzyme activity, HPA also has independent enzymatic functions, such as up-regulation of vascular endothelial growth factor (VEGF) -A and VEGF-C and activation of intracellular signaling pathways involved in, survival, migration and proliferation of tumor cells. It can also induce an hypercoagulability by a non-enzymatic manner. Materials and Methods HPA was tested in several cancer cell lines from ovaries (OVCAR-3, SKOV-3), breast (MDAMB231, MCF7) colon (LS-174), lung (A549), uterus (HELA) and gastric (adenocarcinoma (AGS) and GSRC (KATO-III) using several techniques such as RT-PCR, Q-PCR, immunocytochemistry, flow cytometry and degradation of Fondaparinux at pH 5, evaluated by its anti Xa activity evaluated by Factor Xa amidolytic activity. The amount of HPA mRNA in the biopsy simples of gastric adenocarcinoma (n = 10) and GSRC (n = 11) in tumors and their environment were analyzed. Results HPA gene is expressed in all cancer cell lines, but its level varies depending on the tumor cell line. In biopsies of gastric cancer, the HPA gene is more expressed in the tumor regions (p = 0.0002) and tumor environment (p = 0.015) in GSRC than in gastric adenocarcinoma. B) The activity of HPA, evaluated by degradation of Fondaparinux at pH 5, 1) in the supernatants of 10 6 cancer cells: the residual activity of Fondaparinux after 2 hours incubation at 37°C with OVCAR-3 supernatant was of 70% of control value, and of 80% with KATO-III cell supernatants. 2) in patient’s plasmas, this technique cannot be used because the site of degradation of fondaparinux by heparanase is masked by AT present in plasma. Conclusions Heparanase was found in in many cancer cell lines and its level depends on origin of tumor cells and on its aggressivity. Taking into account the pro-metastatic functions, proangiogenic and procoagulant activity of HPA and its overexpression in gastric signet ring cell carcinoma of poor prognosis and its cell line, HPA can be considered as a biomarker of malignancy and as a therapeutic target in GSRC patients.

Lipid classes (Iatroscan TLC/FID method) and fatty acids (GC/MS) of settling particles and dissolved fraction were investigated in the north Adriatic sea in June 1995. The differences in composition and concentrations were examined according to distance from Isonzo river Estuary, depth and fraction (particulate versus dissolved). Total particulate lipids showed large variations, from 32.6 to 139.5 μg/l. The highest concentration was observed as for POC and total individual fatty acids in surface waters close to the river mouth. The ratio particulate lipids/POC ranged from 0.14 to 0.40 (average 0.27), which expressed different biosynthetic pathways by planktonic communities, as previously shown when nitrogen limitation can favor a switch from protein to lipid metabolism. The highest value was found in surface waters in the central part of the Gulf of Trieste, suggesting the existence of different stress conditions such as nutrient limitation, from those existing near the Isonzo river mouth. Total dissolved lipids did not show large variations (49–88 μg/l). The ratio dissolved lipids/DOC also varied in a narrow range (0.03–0.04), but with much lower values than those found in the particulate fraction. The comparison between particulate and dissolved lipid classes and fatty acids indicated a decoupling between the two reservoirs. Inputs from living organisms and freshly synthesized organic matter were clearly revealed in the dissolved fraction by phospholipids and polyunsaturated fatty acids. Degradation indicators such as free fatty acids and monoacylglycerols were significantly more represented in the particulate fraction than in the dissolved one near the river mouth, whereas the contrary was observed in the central part of the Gulf. Complementary informations were obtained from fatty acid distribution patterns such as for terrestrial originating inputs using the long-chain series. The importance of bacteria was observed using branched fatty acids and 18:1 ω 7. The two bacterial signatures were found in both fractions, with highest imprints near the river mouth. Some enrichment of the branched fatty acids in the dissolved fraction in the central part of the Gulf could be related with the high contribution of polar lipids, suggesting a marked contribution of bacteria to the polar lipid fraction.

The mixing zone between the Danube and the Black Sea was investigated at the front of the Chilia and Sulina branches of the Danube delta, in April–May 1997, during two periods corresponding to conditions at the end of winter (Chilia and Sulina branches) and the beginning of spring (Sulina branch). The distribution of the organic matter in the particulate, colloidal and truly dissolved pools along the salinity gradient was characterized at both global and molecular levels using biochemical parameters. The distribution of particulate organic carbon (POC) paralleled that of total suspended matter in winter, whereas decoupling was observed in spring, reflecting active biological mechanisms in the mixing zone off the Sulina branch during this period. This is supported by distribution patterns of polyunsaturated fatty acids (PUFA) and branched fatty acids (BrFA), which are indicators of phytoplankton and bacteria activities, respectively. The δ 13 C isotopic signature of POC in the Danube–Black Sea mixing zone varied of between −29·1 and −24·6‰, which is consistent with the usual temperate range of estuarine systems. In spring, the observed shift towards lower values in the area of salinity 0–5 suggested a gradual change in the composition of POC, such as that caused by cell lysis of riverine planktonic populations induced by a salinity increase. A subsequent increase of δ 13 C values towards higher salinities indicated phytoplankton growth in the estuarine/marine zone, as assessed by high concentrations of PUFA. Indirect evidence of sedimentation of terrestrial particles in the upper part of the salinity gradient in the range of 2–3 was suggested by the decrease of the content of particles and POC in fatty acids (C 24 –C 32 ) and n-alkanes (C 25 –C 35 ), both constituents of cuticular waxes of higher plants. A tight coupling was suggested between phytoplankton and bacteria by similar distributions of PUFA and BrFA along the salinity gradient. The distribution of dissolved organic carbon (DOC) varied according to the season. In spring, the DOC concentrations remained constant across the salinity gradient in front of the Sulina branch at about 2·7 mg l −1 , whereas higher concentrations, >4 mg l −1 , were observed in winter at stations located in the low salinity (2–4 and 5–8) area. A few data were obtained for δ 13 C of the DOC pool, with an average of −26·9‰ in the Danube River end-member and values close to those of POC off the various branches. The low molecular weight (LMW) fraction of DOC isolated from water by sequential cross-filtration was evaluated by summing the pool of the combined and free amino acids and that of the combined and free carbohydrates. The distribution of LMW DOC along the salinity gradient was similar in the three investigated areas. Off the Sulina branch, proportions of LMW DOC fluctuated between 17 and 37‰ in winter and between 23 and 35‰ in spring. Two zones of high LMW DOC were located in two ranges of salinity—between 2 and 4 and between 5 and 8—probably originating from the release of decaying diatoms, assessed by high molecular proportions of serine in the combined amino acids. LMW DOC indicated a high potential for microbal activity, as shown by concomitant distributions of branched fatty acids.