Abstract
Background
We studied the variation in plasma content of plasmalogen and ganglioside, total cholesterol (TC), and total phospholipid (TPL) in gastric carcinoma patients. The plasma plasmalogen levels were determined according to the vinyl ester bond method.
Material/Methods
Plasma ganglioside level was determined according to the method of Sevennerholm. The total cholesterols and total phospholipid were determined by routine methods.
Results
The plasma plasmalogen level of gastric carcinoma patients was significantly higher than in the control (normal) group, and the difference was markedly significant (p<0.01). The plasma total sialic acid (TSA) and lipid-bound sialic acid (LSA) of gastric carcinoma patients were higher than those of the normal control group (p<0.05). The total cholesterol content was higher than those in the normal control group (p<0.02), but the total phospholipid content was lower than in the normal control group and the difference was markedly significant (p<0.05). In the gastric carcinoma patients group, the plasmalogen and ganglioside-TSA levels were positively correlated (r=0.01, P<0.01). Plasmalogen and total cholesterols were also positively correlated (r=0.82, P<0.01), and plasmalogen and total phospholipid were negatively correlated (r=−0.82, p<0.01).
Conclusions
In gastric carcinoma patients, the plasma plasmalogen content was significantly elevated and was positively correlated with elevated level of gangliosides and total cholesterols, but it was negatively correlated with level of total phospholipids.
MeSH Keywords: Amnion, Cholestasis, Plasmalogens, Stomach Neoplasms
Background
Plasmalogen are phospholipids possessing a vinyl ether bond at the Sn-1 position instead of the usual ester bond found in diacylphospholipids. They are widely distributed in membranes but their role is not well understood. However, their physicochemical properties suggest that they play an important role as membrane constituents. For example, they are involved in signal transduction due to their high level of arachiclonic acid at Sn-2 and may also act as endogenous antioxidants. The reactivity of vinyl may be linked with control of reactive oxygen species [1,2].
Gangliosides (GIS) are important lipid constituents of cell membranes. Chemically, gangliosides are glycosphingolipids containing sialic acid (SA) and are particularly abundant in the membrane microdomain; they are considered as highly organized units with a variety of specific functions [3,4]. Gangliosides are involved in many significant cellular processes, such as cell growth, proliferation, differentiation, and oncogenic transformation [5,6].
In this study we compared plasma content variation and the correlation of plasmalogen, membrane glycolipid, total cholesterol, and total phospholipid in gastric carcinoma patients.
Material and Methods
Material
The clinical diagnosis of 29 gastric carcinoma patients was reliably made by final pathohistological analysis of postoperative tumor tissue.
Methods
Plasma plasmalogen content was determined according to the method for determining vinyl ester bond [7], including the standard curve of inorganic phosphorus, the extract of total lipid, alkali hydrolysis-produced plasmalogen, and the determination of vinyl ester bond of plasmalogen according to iodine disappearance. The gangliosides were determined according to the method of Sevennerholm, including the extraction of plasma ganglioside using chloroform, methanol, and water in a final volume ratio of 1:1:0.8 (C:M:W, v/v/v). Higher phases containing gangliosides were collected and air-dried and the obtained dry ganglioside extract was finally purified by dialysis and filtration. Purified ganglioside was used for quantitative analysis by resorcinol spectrometry method. The total cholesterols and total phospholipid were determined by routine method.
Results
The plasmalogen content compared with ganglioside TSA and LSA of gastric carcinoma patients is shown in Table 1.
Table 1.
The plasmalogen content compared with ganglioside TSA and LSA of gastric carcinoma patients.
| Group | N | Plasmalogen (umol/ml) | TSA (ug/ml) | LSA (ug/ml) |
|---|---|---|---|---|
| Gastric carcinoma | 29 | 0.93±0.34 | 1122.09±118.89 | 364.77±69.59 |
| Normal control | 30 | 0.64±0.26 | 934.04±132.91 | 266.45±57.43 |
| P | <0.01 | <0.05 | <0.05 |
Comparison of plasmalogens and TSA and LSA content of gastric carcinoma patients.
Table 1 shows that plasma plasmalogen level of gastric carcinoma was significantly higher than in the normal control group (p<0.01), while the ganglioside lipid-bound sialic acid (LSA) and total sialic acid (TSA) levels were higher than in the normal control group (p<0.05).
Figure 1 shows the straight-line regression correlation of plasmalogen (PLA) and total sialic acid (TSA) content in gastric carcinoma patients.
Figure 1.
Correlation of PLA and TSA levels in gastric carcinoma patients (r=0.61, t=4.00, p<0.01).
Figure 1 shows that, in gastric carcinoma patients, plasma plasmalogen content was positively correlated with elevation of TSA (r=0.61).
Table 2 compares the plasma plasmalogen with total phospholipid and total cholesterol content of gastric carcinoma patients.
Table 2.
Comparison of plasma plasmalogen, TPL, and TC content in gastric carcinoma patients.
| Group | N | Plasmalogen (umol/ml) | TPL (umol/ml) | TC (umol/ml) |
|---|---|---|---|---|
| Gastric carcinoma | 29 | 0.93±0.34 | 2.72±0.59 | 4.96±1.64 |
| Normal control | 30 | 0.69±0.26 | 3.02±0.34 | 3.89±0.69 |
| P | <0.01 | <0.05 | <0.02 |
Table 2 shows that the plasma plasmalogen content of gastric carcinoma patients was significantly higher than in the normal control group (p<0.01), and the plasma TPL content of gastric carcinoma patients was lower than in the normal control group (p<0.05). The plasma TC content of gastric carcinoma patients was significantly higher than in the normal control group (p<0.02).
Figure 2 shows the straight-line regression correlation of plasmalogen (PLA) and total cholesterol (TC) in gastric carcinoma patients.
Figure 2.
Correlation of PLA and TC levels in gastric carcinoma patients (r=0.82, t=7.44, P<0.01).
Figure 2 shows that, in gastric carcinoma patients, plasma plasmalogen content was positively correlated with TC.
Figure 3 shows the straight-line regression correlation of plasmalogen (PLA) and total phospholipid (TPL) in gastric carcinoma patients.
Figure 3.
Correlation of PLA and TPL levels in gastric carcinoma patients (r=−0.82 t=7.44 p<0.01).
Figure 3 shows that the plasma plasmalogen content in gastric carcinoma patients was negatively associated with TPL(r=−0.82).
Discussion
Cells contain a membrane system composed of membrane protein and membrane lipid. Membrane lipid includes phospholipid, glycolipid, cholesterol, and cholesterol ester. Phospholipid (specific glycerophosphatide) is the main lipid in biological membranes, accounting for about 70% of total membrane lipids [8].
Plasmalogen exists in mammals and contains vinyl ether bond glycerol phospholipids such as plasmenyl ethanolamine, plasmenyl choline, and plasmenyl serine. Plasmenyl ethanolamine is the major storage depot of arachidonic acid [9]. Arachidonic acid is metabolized to eicosanoids and the lysoplasmenylcholine can activate myocardial cAMP-dependent protein kinase. This suggests that lysoplasmenylcholine serves as a second messenger in signal transduction [10]. Concerning the relationship of plasmalogen and tumors, Merchant et al. reported that the plasmalogen levels of 16 malignant and 11 non-malignant human colon specimens were analyzed using a chloroform-methanol analytical reagent in conjunction with 31p magnetic resonance spectroscopy (MRS). Results show a statistically significant elevation in the relative concentration of lysophosphatidylcholine and phosphatidylcholine plasmalogen. Sphingomyelin was lower in malignant tissues [11,12]. In our research, the plasma plasmalogen level of gastric carcinoma was significantly higher than in the normal control group (p<0.01). Although many studies consistently reported higher concentration of plasma plasmalogen in cancer patients, the mechanism is not yet understood. The mechanism may be that the key plasmalogen enzyme, phosphodihydroxyacetone acyltransferase, strengthens activity [13]. Phosphatidyl cytonucleotide transferase activity can strengthen synthesis of plasmalogen [8]. However, expression of plasmalogen phospholipase C and phospholipids D was reduced [14].
The term “gangliosides” includes GIS-containing sialic acid, which consists of lipid-bound sialic acid (LSA) and total sialic acid (TSA). We found that the plasma LSA and TSA levels of gastric carcinoma patients was significantly higher than in the normal control group (p<0.05). The mechanism by which ganglioside levels are increased in gastric carcinoma patients may be the sudden change of the chromatin cancer gene due to physical, chemical, or biological factors [15]. The increase in glycolipid glycosyltransferases activity strengthens membrane glycolipid biosynthesis [16]. It has been reported that tumor cells may shed their gangliosides into the circulation, resulting in higher ganglioside concentration in gastric carcinoma patients [17].
Gastric carcinoma patients have high total cholesterol and low phospholipids, as well as abundant low-density lipoprotein, plasmalogen, and cholesterol. High cholesterol levels may increase plasmalogen levels. A nearly 2-fold increase in the cholesterol synthetic key enzyme HMGCoA-reductase activity in liver tumor cells was reported [18]. In 14 meningioma patients, plasmalogen content rose because of plasmenyl ethanolamine increase, and the decreased total phospholipids levels caused lower levels of phosphatidylcholine, lysophosphatidylcholine, and phosphatidylinositol [19].
Conclusions
In gastric carcinoma patients, the plasma plasmalogen content was significantly elevated; it was positively correlated with elevation of gangliosides and total cholesterols, and was negatively correlated with total phospholipids levels.
Footnotes
Source of support: This research was supported by the National Natural Science Fund of China (No. 30900243) and the Anhui Province Key Laboratory of Active Biological Macro-Molecules (Wannan Medical College) (No.1306c083008)
References
- 1.McMaster CR, Lu CQ, Choy PC. The existence of a soluble plasmalogenase in guinea pig tissues. Lipids. 1992;27:945–49. doi: 10.1007/BF02535569. [DOI] [PubMed] [Google Scholar]
- 2.Saini-Chohan HK, Hatch GM. Biological actions and metabolism of currently used pharmacological agents for the treatment of congestive heart failure. Curr Drug Metab. 2009;10:206–19. doi: 10.2174/138920009787846314. [DOI] [PubMed] [Google Scholar]
- 3.Gilbert ER, Eby JM, Hammer AM, et al. Positioning ganglioside D3 as an immunotherapeutic target in lymphangioleiomyomatosis. Am J Pathol. 2013;183:226–34. doi: 10.1016/j.ajpath.2013.04.002. [DOI] [PubMed] [Google Scholar]
- 4.Yin X, Xiang T, Li L, et al. DACT1, an antagonist to Wnt/beta-catenin signaling, suppresses tumor cell growth and is frequently silenced in breast cancer. Breast Cancer Res. 2013;15:R23. doi: 10.1186/bcr3399. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Rathod SR, Khan F, Kolte AP, Gupta M. Estimation of salivary and serum total sialic Acid levels in periodontal health and disease. J Clin Diagn Res. 2014;8:ZC19–21. doi: 10.7860/JCDR/2014/9615.4800. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6.Schiopu C, Flangea C, Capitan F, et al. Determination of ganglioside composition and structure in human brain hemangioma by chip-based nanoelectrospray ionization tandem mass spectrometry. Anal Bioanal Chem. 2009;395:2465–77. doi: 10.1007/s00216-009-3188-8. [DOI] [PubMed] [Google Scholar]
- 7.Lu CQ, Choy PC. the distributive study of plasmalogen in guinea pig tissues. Sheng Wu Hua Xue Yu Sheng Wu Wu Li Xue Bao (Shanghai) 1996;28:210–13. [PubMed] [Google Scholar]
- 8.Schrakamp G, Schutgens RB, Wanders RJ, et al. The cerebro-hepato-renal (Zellweger) syndrome. Impaired de novo biosynthesis of plasmalogens in cultured skin fibroblasts. Biochim Biophys Acta. 1985;833:170–74. doi: 10.1016/0005-2760(85)90266-8. [DOI] [PubMed] [Google Scholar]
- 9.Dueck DA, Chan M, Tran K, et al. The modulation of choline phosphoglyceride metabolism in human colon cancer. Mol Cell Biochem. 1996;162:97–103. doi: 10.1007/BF00227535. [DOI] [PubMed] [Google Scholar]
- 10.Brautigam C, Engelmann B, Reiss D, et al. Plasmalogen phospholipids in plasma lipoproteins of normolipidemic donors and patients with hypercholesterolemia treated by LDL apheresis. Atherosclerosis. 1996;119:77–88. doi: 10.1016/0021-9150(95)05632-7. [DOI] [PubMed] [Google Scholar]
- 11.Merchant TE, Kasimos JN, de Graaf PW, et al. Phospholipid profiles of human colon cancer using 31P magnetic resonance spectroscopy. Int J Colorectal Dis. 1991;6:121–26. doi: 10.1007/BF00300208. [DOI] [PubMed] [Google Scholar]
- 12.Rana FR, Harwood JS, Mautone AJ, Dluhy RA. Identification of phosphocholine plasmalogen as a lipid component in mammalian pulmonary surfactant using high-resolution 31P NMR spectroscopy. Biochemistry. 1993;32:27–31. doi: 10.1021/bi00052a005. [DOI] [PubMed] [Google Scholar]
- 13.Sugiura T, Fukuda T, Masuzawa Y, Waku K. Ether lysophospholipid-induced production of platelet-activating factor in human polymorphonuclear leukocytes. Biochim Biophys Acta. 1990;1047:223–32. doi: 10.1016/0005-2760(90)90520-8. [DOI] [PubMed] [Google Scholar]
- 14.de Vet EC, Ijlst L, Oostheim W, et al. Alkyl-dihydroxyacetonephosphate synthase. Fate in peroxisome biogenesis disorders and identification of the point mutation underlying a single enzyme deficiency. J Biol Chem. 1998;273:10296–301. doi: 10.1074/jbc.273.17.10296. [DOI] [PubMed] [Google Scholar]
- 15.Byers DM, Gorbet JC, Irwin LN. Disialogangliosides and TNFalpha alter gene expression for cytokines and chemokines in primary brain cell cultures. Neurochem Res. 2012;37:214–22. doi: 10.1007/s11064-011-0587-y. [DOI] [PubMed] [Google Scholar]
- 16.Suzuki Y, Yanagisawa M, Ariga T, Yu RK. Histone acetylation-mediated glycosyltransferase gene regulation in mouse brain during development. J Neurochem. 2011;116:874–80. doi: 10.1111/j.1471-4159.2010.07042.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 17.Prastawa M, Bullitt E, Gerig G. Simulation of brain tumors in MR images for evaluation of segmentation efficacy. Med Image Anal. 2009;13:297–311. doi: 10.1016/j.media.2008.11.002. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 18.Vance JE. Lipoproteins secreted by cultured rat hepatocytes contain the antioxidant 1-alk-1-enyl-2-acylglycerophosphoethanolamine. Biochim Biophys Acta. 1990;1045:128–34. doi: 10.1016/0005-2760(90)90141-j. [DOI] [PubMed] [Google Scholar]
- 19.Zoeller RA, Lake AC, Nagan N, et al. Plasmalogens as endogenous antioxidants: somatic cell mutants reveal the importance of the vinyl ether. Biochem J. 1999;338(Pt 3):769–76. [PMC free article] [PubMed] [Google Scholar]