Application of two dimensional electrophoresis to characterise hormonally sensitive proteins in the normal and abnormal uterus

Two-dimensional electrophoresis of synovial tissue, synovial fluid and serum in patients with rheumatoid arthritis and related diseases

Using the technique of two-dimensional (2D) electrophoresis with consecutive silver staining, we investigated samples of serum, synovial fluid and synovial tissue obtained from 19 patients suffering from rheumatoid arthritis (RA) or non-RA arthritis. From these experiments we have drawn the following conclusions. 2D electrophoresis of serum, synovial fluid and synovial tissue extracts taken from patients suffering from joint diseases is a reproducible method. Repeated runs of the same sample reveal an essentially constant protein spot pattern. The time period between surgery and tissue preparation did not influence the number of protein spots when less than 15 h was involved. The protein spot number is always lower in synovial fluid than in either synovial tissue or serum in RA and non-RA patients. The mean value for the number of spots is 68 for the inflamed tissue irrespective of the cause of arthritis (RA and non-RA group taken together) and 47 for the control group. This difference is significant. We were able to definitely identify 7 spots in the tissue extract. We did not find RA-specific protein spots in either serum, synovial fluid or tissue extracts from the synovial membrane. The only significant difference between RA patients and either non-RA or control group patients concerning the protein spot pattern is the increased size of the immunoglobulin spot (mainly IgG) in RA. In addition, we discuss possible reasons for failure of the 2D electrophoresis technique to detect disease-specific protein patterns.

Progestin regulation of protein synthesis in endometrial cancer

Protein synthesis in cancerous and normal human endometrium was investigated by the incorporation of [35S]methionine and analysis of products by two-dimensional polyacrylamide gel electrophoresis. Comparison of the cellular products from organ cultures of endometrial carcinoma, obtained from each subject before and after in vivo administration of medroxyprogesterone acetate (MPA) for 10-14 days revealed: (i) a decrease in the synthesis of tubulin and of a protein of molecular weight (mol. wt) 68 kDa, isoelectric point (pI) 6.0, and (ii) an increase in the synthesis of creatine kinase (CK) and of protein of mol. wt 36 kDa, pI 4, following MPA therapy. The 68 kDa protein was expressed at relatively reduced levels in organ cultures of normal human endometrium throughout the menstrual cycle. In primary cultures of normal human endometrium throughout the menstrual cycle. In primary cultures from cancerous endometrium endometrium established for several weeks the 68 kDa protein was not expressed but could be induced by heatshock. Primary cultures were also used to investigate the early events following progesterone stimulation which revealed a decrease in synthesis of a protein mol. wt 36 kDa, pI 8 at 8 h following administration.