The Research On Funcion And Regulation Of Histone Demethylase JMJD1A On Kidney Cancer

Histone posttranslational modification can effect specific gene expression, which plays an important role in many physiological processes and is one of research hot in current life science. Reversible histone methylation can be catalyzed by histone methyltransferases and demethylases, which plays biological function through regulating histone structure. Histone demethylase JMJD1A catalyzes demethylation of mono- and di-methy H3K9（H3K9me1/2） and plays gene activation, such as nuclear receptor activation, sperm development, metabolism and hypoxic regulation. The function and regulated mechanism of JMJD1A in kidney development is unknown. In this research, the expression and regulation was investigated in with clinical specimems, kidney cancer cell lines and mice though quantitative real-time reverse transcription polymerase chain reaction （RT-PCR）, western blotting, immunohistochemistry and immunofluorescence methods at mRNA, protein and cell levels.The results follow:1. JMJD1A is involved in the development of kidney cancer.The quantitative RT-PCR, western blotting and immunohistochemistry methods were used in renal cell carcinoma tissue and adjacent tissue and found that JMJD1A was higher in cancer tissue. JMJD1A is especially located around vessel of cancer tissue and may be participate in angiogenesis.2. JMJD1A is a hypoxia regulated geneUnder mimicking hypoxia （adding NiCl₂ or CoCl2） and real hypoxia（1% O2） culture condition, the expression of JMJD1A mRNA and protein is upregulated. And the same time, the stability of hypoxia-inducible factor-1α（HIF-1α） protein increases. These results indicate that JMJD1A is a hypoxia response gene3. Ascorbate inhibits the upregulation of NiCl₂ induced JMJD1A expressionThe different concentrated NiCl₂ solutions were used to treat kidney cancer cell lines, and then the quantitative RT-PCR, western blotting and immunofluorescence methods were used to measure the JMJD1A expression at mRNA, protein and cell levels. The results indicate JMJD1A expression is NiCl₂ concentration-dependently upregulated. After adding different concentrated ascorbate, the JMJD1A expression decreases which means that the anticancer role of ascorbate may be achieved through influencing histone methylation.4. JMJD1A is developmental related geneThe quantitative RT-PCR and western blotting methods were used to analyze the JMJD1A expression in mice kidney at the age of 2 weeks, 4 weeks and 6 weeks. The results indicate that mRNA and protein of Jmjd1a is lower in 6 weeks than 2 weeks and 4 weeks, which means Jmjd1a roles is related to kidney development.5. Ascorbate protective role for alcoholic liver disease in mice through regulating iron metabolismIn mice, ascorbate can up-regulate hepcidin expression to repress iron absorption of alcoholic liver disease and down-regulate TfR1 expression in liver to decrease iron overload and liver injuries, which means ascorbate protective role can be achieved through influencing iron metabolism.Conclusion: In this study,these were discovered that the increased expression of histone demethylase JMJD1A is associated with the occurrence of kidney cancer. JMJD1A is also a hypoxic regulated gene in kidney cancer cell lines and may play a biological role through influencing the expression of other hypoxic genes. Ascorbate has many protective roles, such as anticancer activity by inhibiting NiCl₂-induced upregulation of JMJD1A and antioxidant activity for alcoholic liver disease by suppressing iron absorption. This discovery proved that JMJD1A may be a new key molecular for kidney cancer and provide an important target for the diagnosis and treatment. These results highlight histone modification is important in kidney cancer development and support data for ascorbate preventive role for kidney cancer.