Fibronectin protein expression in renal cell carcinoma in correlation with clinical stage of tumour.

Background: Carcinogenesis is a multistep process which involves interplay between the tumour cells and the matrix proteins. This occurs by adherence between the tumour cells and proteins in the extracellular matrix. VHL mutation affects through the hypoxia inducible factor (HIF) and causes changes in various tissue proteins like VEGF, PDGF, TGF, Fibronectin and others. As not much literature is available, we aim to quantify the changes of fibronectin protein in renal cell carcinoma (RCC) tissue.

Methods: This Prospective unbalanced case control study was conducted over a period of 18 months from April 2016 to September 2017. The patients undergoing nephrectomy for the diagnosis of RCC were included in the study after obtaining written informed consent. Patients were excluded from study, if normal renal tissue could not be identified in the resected kidney and if the artery clamp time to retrieval of tissue was more than 30 min. Fibronectin protein is estimated in the tumour tissue by gel electrophoresis and western blotting which is compared with that of normal kidney tissue of the same kidney. Results have been expressed as absolute values with standard deviation and relative expression (RE).

Results: Of the 21 patients analysed 15 showed an increase in fibronectin expression in the renal tumour tissue while 6 did not. The mean expression of Fibronectin protein has increased 1.5 times in the tumour tissue when compared with the normal tissue. The increase was 1.54 times in early tumours compared to 1.37 times in advanced tumours of RCC.

Conclusions: Fibronectin showed a 1.5 times increase in the tumour compared to normal. This increase is more in Stage 1&2 tumours when compared to the Stage 3&4 tumours.