Chromatographic Determination of Total Cholesterol in Human Lung Healthy and Cancer Tissues of the Same Patient

Summary

Cholesterol is an essential component of mammalian cells, but its role in cancer is unclear. We have determined the total cholesterol content in the healthy and the cancerous lung tissues of the same patient. Tissues of 13 patients (7 women and 6 men, different histological type, different stages of the disease) were obtained during surgical intervention. The samples (0.056–2.004 g) were hydrolyzed in alkaline medium, and the total cholesterol was extracted into n-hexane and simultaneously determined by thin-layer chromatography (TLC) on silica gel high-performance thin-layer chromatography (HPTLC) plates and nonaqueous reversed-phase high-performance liquid chromatography (HPLC), which both proved to be suitable for the determination of cholesterol in lung tissues and gave comparable results. This is the first report about the comparison of the total cholesterol content in the healthy and the cancerous tissue of the same patient. The difference in the results for the total cholesterol from both types of tissues was remarkable. For 13 patients, the mean contents and standard deviations determined by TLC were 4.01 ± 0.75 mg g⁻¹ in the healthy lung tissue and 7.75 ± 1.93 mg g⁻¹ in the cancerous lung tissue. Comparable results were obtained by HPLC analyses of the same samples: 3.91 ± 0.73 mg g⁻¹ in the healthy and 6.95 ± 1.83 mg g⁻¹ in the cancerous lung tissue. The range of total cholesterol content determined by TLC was between 3.20 mg g⁻¹ and 5.83 mg g⁻¹ in healthy lung tissues, and between 4.64 mg g⁻¹ and 12.01 mg g⁻¹ in lung cancer tissues, while the ranges obtained by HPLC were between 2.80 mg g⁻¹ and 5.49 mg g⁻¹ for healthy lung tissue, and between 4.38 mg g⁻¹ and 11.24 mg g⁻¹ for lung cancer tissue. The cancerous lung tissue of each of the thirteen patients contained higher amounts of total cholesterol compared to their healthy lung tissue. In 8 of the patients, the total chole sterol in the cancer tissue was more than 60% higher than in the healthy tissue; furthermore, in 5 patients, it was more than 100% higher.