The Serophysiological Study On The Effects And Its Mechanisms Of High-fat Diet On Proliferation Of Human Lung Adenocarcinoma Cell Line SPCA1

Objective:The present study was designed to assess the effect of the diet high in fat on proliferative activities of lung adenocarcinoma cell line SPCA1 by means of serophysiological method, and to define the mechanisms separately from whole level and cellular level.Methods:1 Effects of activated or inactivated rat serum (10%, 15%, 20%) on cell proliferation were detected separately by MTT assay and doubling time to define the suitable conditions for cell culture.2 Female Sprague-Dawley rats were fed with common chow or high-fat diet (lard:common chow = 1:9, w/w) for 7 weeks, and serum was obtained by centrifugal method. MTT assay, [~3H] thymidine incorporation method and flow cytometric analysis were performed to identify cell proliferative activity, DNA duplication and cell cycle distribution, which were examined to discuss the effects ofRat' s Serum Treated with High-fat Diet (RSTHFD) on proliferation of cancer cells.3 Lipids, insulin and estrogen levels in serum were examined and body weights were weighed to study the whole level mechanism on the effects of high-fat diet.4 Flow cytometric analysis was performed to measure the percentage of hypodiploid cells (apoptotic cells). Intracellular localization of estrogen receptor(ER) was determined by immunohistochemical staining.Results:1 The rat serum concentration supplemented in culture medium was 15%, and serum was inactivated.2 RSTHFD can accelerate DNA duplication, cell proliferation and cell mitosis.3 Subcutaneous and visceral fat accumulated in rats which were fed with high-fat diet. There were no significant differences in body weight, serum lipids and insulin levels between two groups. Rats fed with high-fat diet significantly had an elevated circulating level of estrogen, which was involved in the mechanism of cell proliferation.4 ER was localized in the cytoplasm and partly in nuclei, and might be a key contributor to cell proliferation. In the meantime, RSTHFD was found to decrease the number of apoptotic cells, then subsequently displayed activity of promoting cell proliferation.Conclusions:1 Fifteen percent of inactivated rat serum is suitable condition for culturing SPCA1 cells.2 High-fat diet can stimulate the proliferative activity of SPCA1 cells in the present study.3 The mechanisms may be as follows:â–  High-fat diet elevated estrogen concentrations which highly contributed to cell proliferation.â–  ER exsists in SPCA1 cells, which indicated cell proliferation might be induced by ER-dependent pathway.â–  The findings presented by flow cytometry showed that RSTHFD inhibited cell apoptosis and ultimately promoted cell proliferation.