Korean J Transplant.  2020 Dec;34(Supple 1):S97. 10.4285/ATW2020.PO-1077.

The efficacy of klotho gene as a biomarker of cancer development in kidney transplant recipients

• Park WY
• Lee HK
• Kwon O
• Kim Y
• Paek JH
• Jin K
• Han S

• KMID: 2509245
• DOI: http://doi.org/10.4285/ATW2020.PO-1077

Abstract

Background
The klothogene is known as a co-receptor of FGF23 in the chronic kidney disease-mineral bone disease, but recently, it has been reported that klotho is associated with the occurrence of cancer in the general population. However, the association between klotho gene and the development of cancer in kidney transplant recipients (KTRs) is uncertain. Therefore, we aimed to investigate the effect of klotho gene as a biomarker of the cancer development and the factors associated with the development of cancer in KTRs.
Methods
We investigated a total of 45 non-dialysis chronic kidney disease (ND-CKD) patients, dialysis patients, and KTRs diagnosed and treated for gastric cancer, thyroid cancer, and kidney cancer at Keimyung University Dongsan Medical Center from January 2009 to December 2018. We measured the serum klotho level and expression status in the tissue, the serum levels of malondialdehyde (MDA), and superoxide dismutase (SOD) as oxidative stress markers, with the stored samples in the biobank.
Results
The serum klotho level was the lowest in kidney cancer compared to gastric and thyroid cancer, whereas the level of oxidative stress markers was the highest in kidney cancer. In 12 patients diagnosed to kidney cancer, the serum klotho level was the lowest and MDA level was the highest in KTRs, but SOD showed no difference among them. Comparing normal and tumor tissues by western blot analysis, klotho expression was decreased in tumor tissues compared to normal tissues in all three groups, but klotho expression in KTRs only was deceased in tumor tissues compared to normal tissues by real-time polymerase chain reaction. This shows the relationship between the development of kidney cancer and inhibition of klotho gene in KTRs through the mechanism of oxidative stress.
Conclusions
The klotho gene may play a role as a biomarker of cancer development with the mechanism of oxidative stress in KTRs.