Mutational screening and investigation of gene expression status of bikunin gene among bladder and kidney cancer patients

Alpha-1-mikroglobulin/bikunin precursor gene comprises 10 exons and 9 introns, 20 kb in length. First six exons encode Alpha-1-mikroglobulin, 8th and 9th exons encode Kunitz domains, 7th and 10th exons encode C and N terminal regions of bikunin. Experimental and clinical results show that bikunin functions in many processes. Bikunin acts as protease inhibitor in cell growth and spread of tumor cells. Bikunin provides significant reduction in expression of uPA and uPAR, thus the invasion and metastasis of tumor cells. There are some experiments based on bikunin protein level in bladder and kidney cancers. However, there is no such a detailed study at molecular level performed with bladder and kidney tumors. Bikunin molecular function in these cancers remains unclear. Herein, total RNA and DNA were obtained from normal and tumor tissues of 19 bladder and 50 kidney cancer patients. Using RNA samples, bikunin mRNA levels were detected using semi-quantitative RT-PCR. Mutational screening was performed at the exons of bikunin gene via SSCP. SNPs were shown using automatic sequencing device. mRNA levels of bikunin in tumor tissues decreased compared with normal tissues in bladder cancer. However, there is no significant difference between tumor and normal samples of bladder (p>0,05). In kidney cancer, bikunin mRNA levels decreased significantly in tumor tissues compared with normal tissues (p<0,05). rs80057939 was detected at the 10th exon of bikunin in tumor tissues (p>0,05). In conclusion, bikunin might contribute to kidney cancer pathogenesis and may be used as a potential marker and drug for diagnosis and treatment.