Protein expression within the human renal cortex and renal cell carcinoma: The implication of cold ischemia

Abstract

Cold ischemia of tissue during tissue treatment may influence protein expression, but has not been well studied. Better understanding of this is fundamental prior to using stored fresh-frozen tissue where the time from organ harvest until tissue collection and storage is most often not documented. We collected samples from normal renal cortex and cancerous tissues at serial time points for up to 60 min from three nephrectomized individuals with newly diagnosed clear cell renal cell carcinoma (RCC). Samples were processed onto protein chips and identified using surface-enhanced laser desorption/ionization- time of flight mass spectrometry (SELDI). The number and size of proteins expressed at separate sites within homogenous tissue sections were comparable. Cold ischemia time neither affected the number nor the size of proteins expressed. While the quantity of most proteins was similar between separate sites and unaffected by cold ischemia time, we noted variation in the quantity of some proteins compared to duplicate measurements. Such variation was noted between separate samples collected at same cold ischemia time points. Taken together, these data indicate that cold ischemia time for up to 60 min does not influence the number or size of proteins expressed within renal tissue. © Mary Ann Liebert, Inc.