Cholesterol content in tumor tissues is inversely associated with high-density lipoprotein cholesterol in serum in patients with gastrointestinal cancer

Abstract

Background. The authors have previously demonstrated in different experimental models that sustained processes of cellular growth are characterized by alterations of cholesterol metabolism not only in the proliferating tissues but also in the plasma compartment. Methods. To evaluate whether alterations of cholesterol metabolism similar to those observed in experimental models are also associated with human cancer, in the present study cholesterol distribution in tumor tissues and lipid composition in the plasma compartment were determined in patients with different types of gastrointestinal cancer. Results. The results showed that tumor tissues contain increased amounts of cholesterol when compared with the corresponding normal tissues. Intracellular alterations of cholesterol were accompanied by specific changes of cholesterol in the plasma compartment: high‐density lipoprotein (HDL) cholesterol was markedly reduced in the serum of patients with gastrointestinal cancer and the lipoprotein profiles showed a decrease in HDL3 fraction, the main HDL subfraction in human serum. The decrease of HDL cholesterol was negatively associated with the clinical stage of the disease. No changes in either total or low‐density lipoprotein cholesterol levels were observed. Conclusions. A major function attributed to HDL is to maintain normal cell cholesterol homeostasis by removing excess of cholesterol from intracellular pools. Because the use and storage of cholesterol are increased within the tumor tissues during growth, it is possible to hypothesize that low HDL levels observed in patients with gastrointestinal cancer are associated with the increased cholesterol metabolism in proliferating tissues.

Lipid profile in acute viral hepatitis: A study from north eastern India

“…Majority of the plasma lipids have their synthetic pathway in the liver and thus an intact cellular function is a pre-requisite for a balanced lipid metabolism [6]. Besides the synthesis of lipoproteins certain key enzymes of lipid metabolism including lecithin cholesterol acyltransferase (LCAT), hepatic lipase are also synthesized in the liver [9]. Furthermore, liver also regulates the catobolosm of plasma lipoproteins by lipoprotein receptors located on the hepatic cell surface thus maintain a degree of equilibrium between the lipoprotein fractions [10].…”

Perturbations of triglycerides but not of cholesterol metabolism are prevented by anti-tumour necrosis factor treatment in rats bearing an ascites hepatoma (Yoshida AH-130)

“…Previous studies by our laboratories Changes in lipid metabolism are a common feature during neoplastic growth, both in humans and in different experimental model systems (Clark and Crain, 1986;Dessi et al, 1986Dessi et al, , 1989Dessi et al, ,b, 1994. However, the mechanisms underlying these changes are stfill unclear and complicated by the fact that the metabolic alterations are species specific and dependent on the histological type or the degree of malignancy.…”

“…Alterations in the synthesis, uptake and intracellular content of cholesterol have been observed in a variety of experimental tumour models as well as in different types of human neoplasms (Anderson et al, 1981;Coleman and Lavietes, 1981;Yachnin et al, 1983;Dessi et al, ,b, 1994.Choksterol perturbations also include change in lipoprotein profiles in plasma compartment. In particular, a definite decrease in high-density lipoprotein (HDL) klvels is a consistent finding in both experimental rat tumours and human neoplass (Dessi et at., 1991(Dessi et at., ,b, 1994 despite the differences reported to exist between lipoprotein metabolism in rodents and humans (Dietschy et al, 1993).…”

“…In particular, a definite decrease in high-density lipoprotein (HDL) klvels is a consistent finding in both experimental rat tumours and human neoplass (Dessi et at., 1991(Dessi et at., ,b, 1994 despite the differences reported to exist between lipoprotein metabolism in rodents and humans (Dietschy et al, 1993). In contrast, changes in other serm lipid parameters, such as total cholsterol and tnglyceride klvels, appear to vary and to be speces specific and dependent on the histological type or tumour grade (Dessi et al, 1991(Dessi et al, ,b, 1994. Therefore, it is possible that the mechanistic basis for the altered HDL levels is different from that responsible for the observed changes in other serum lipid parameters.…”

“…Alterations in the synthesis, uptake and intracellular content of cholesterol have been observed in a variety of experimental tumour models as well as in different types of human neoplasms (Anderson et al, 1981;Coleman and Lavietes, 1981;Yachnin et al, 1983;Dessi et al, ,b, 1994.…”