ABSTRACT
ObjectiveTo investigate the expression level of angiopoietin-like protein 2 (ANGPTL2) in pancreatic cancer patients with or without diabetes and the clinical value of ANGPTL2 as a prognostic marker in patients with pancreatic cancer. MethodsSerum samples were collected from 125 pancreatic cancer patients who were treated in The First Affiliated Hospital of Guangxi Medical University, Guangxi Medical University Cancer Hospital, and Wuming Hospital of Guangxi Medical University from January 2015 to January 2018, among whom 64 had pancreatic cancer alone and 61 had pancreatic cancer and diabetes, and 66 individuals who underwent physical examination were enrolled as control group. ELISA was used to measure the serum level of ANGPTL2, and the association of the expression level of ANGPTL2 with clinical indices, survival, and prognosis was analyzed. A one-way analysis of variance was used for comparison of normally distributed continuous data between three groups, and the Bonferroni test was used for comparison between two groups. The independent-samples Kruskal-Wallis H test was used for comparison of continuous data with skewed distribution between three groups and the one-way ANOVA analysis was used for comparison between two groups. The chi-square test was used for comparison of categorical data between groups. Spearman correlation analysis was also performed to investigate correlation. The Kaplan-Meier method was used to plot survival curves, and the log-rank test was used for comparison of survival rate. The Cox risk model was used to perform univariate and multivariate analyses to determine independent risk factors for the prognosis of pancreatic cancer. ResultsThe pancreatic cancer+diabetes group had a significantly higher serum concentration of ANGPTL2 than the pancreatic cancer group and the control group ［7.79 (7.12-8.17) ng/ml vs 5.74 (508-6.40) ng/ml and 3.72 (3.25-4.16) ng/ml, χ2=126.367, P＜0.001］. Serum ANGPTL2 concentration was positively correlated with carbohydrate antigen 19-9 (CA19-9) and carcinoembryonic antigen (CEA) (r=0.560 and 0.731, both P＜0.001). The univariate analysis showed that tumor size, distant organ metastasis, degree of tumor differentiation， CEA, ANGPTL2, and HbA1c were closely associated with the long-term survival of pancreatic cancer patients, and the multivariate analysis showed that tumor size (HR=2.657,P=0.005), distant organ metastasis (HR=5.000,P=0.014), degree of tumor differentiation (HR=2.466,P=0.004), CEA(HR=1.110,P＜0.001) and ANGPTL2(HR=1.901,P=0.001) were independent risk factors for the prognosis of pancreatic cancer patients. For all pancreatic cancer patients, the high ANGPTL2 expression group had a significantly lower 2-year survival rate than the low ANGPTL2 expression group (8.51% vs 25.81%, χ2=5.651, P=0.017). For the pancreatic cancer patients with diabetes, the high ANGPTL2 expression group had a significantly lower 2-year survival rate than the low ANGPTL2 expression group (2.20% vs 32.70%, χ2=24.895, P＜0.001).ConclusionANGPTL2 can be used as an effective clinical index to evaluate the prognosis of pancreatic cancer patients, especially those with diabetes.
ABSTRACT
<p><b>OBJECTIVE</b>Attempting to isolate and cultivate the microcytin-RR-producing cyanobacteria from natural blooms as well as to further investigate some characteristics of their growth and metabolite toxicity.</p><p><b>METHODS</b>Capillary-pipette method was used to isolate wild Microcystis strains collected from eutrophicated lakes. The isolated strains were cultured in BG11 media at (25 ± 1) °C, under 2 000 lx illumination of fluorescent light with a light-dark rhythm of 12-12 h. The growth curve was observed by measuring optical density of culture suspension, toxin-related genes and the metabolite toxins were identified separately by PCR and HPLC, and its acute toxicity was carried out by orally administered toxins to Kunming (KM) mice.</p><p><b>RESULTS</b>One of five toxigenic strains from 198 collected samples was confirmed to be a MC-RR producing blue-green alga by existing two specific toxin-synthesized enzyme genes and showing specific chromatographic peak of the toxin compared with standard MC-RR through both PCR and HPLC methods. The toxic strain was classified as Microcystin aeruginosa by morphologic and phylogenetic tree analysis. The growth length of the strain lasted nearly 81 days with 55-60 days' exponential phase and the maximal concentration of 5.52 × 10⁷ cell/ml. The LD50 of the MC-RR to the KM mice ranged from 10.75 mg/kg to 13.45 mg/kg of body weight. As a result of the acute toxicity, the enzymatic indexes in serum such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH) were significantly higher than those in the control group. The levels of ALT, AST, ALP and LDH in the treated group at 45 min were (157.08 ± 20.38), (333.00 ± 68.53), (392.70 ± 89.59) and (1 071.13 ± 160.22) U/L respectively, and at 4 h were (514.68 ± 156.87), (593.15 ± 40.41), (618.55 ± 208.76) and (2 281.72 ± 866.67) U/L respectively, and meanwhile the values of ALT, AST, ALP and LDH in the control group were (40.30 ± 4.89), (142.70 ± 26.59), (56.90 ± 11.89) and (509.50 ± 94.75) U/L separately (t values at 45 min were -11.20, -5.77, -7.38, -6.60 respectively, and at 4 h were -6.04, -20.21, -5.35, -4.07 respectively, P values were all <0.01). The liver coefficient in the treated group at 45 min and 4 h were 6.855 ± 0.225 and 8.409 ± 0.276, significantly higher than that (5.784 ± 0.286) in the control group (t values were -3.96 and -12.22, P values were both <0.01). The histopathological changes of liver were hyperemia obviously.</p><p><b>CONCLUSION</b>Isolated from the bloom waters, a strain of Microcystis aeruginosa is obtained with characteristics of longer growth duration, positive microcystin synthetase genes, and dominant production of MC-RR. The LD50 of the extracted MC-RR administered by oral route to mice is (12.10 ± 1.35) mg/kg of body weight, and liver is the target organ of MC-RR. The existence and potential risk of MC-RR in China cannot be ignored.</p>