KDM8, a H3K36me2 histone demethylase that acts in the cyclin A1 coding region to regulate cancer cell proliferation

Abstract

Localized chromatin modifications of histone tails play an important role in regulating gene transcription, and aberration of these processes leads to carcinogenesis. Methylated histone lysine residues, a key player in chromatin remodeling, are demethylated by the JmjC class of enzymes. Here we show that JMJD5 (now renamed KDM8), a JmjC family member, demethylates H3K36me2 and is required for cell cycle progression. Chromatin immunoprecipitation assays applied to human genome tiling arrays in conjunction with RNA microarray revealed that KDM8 occupies the coding region of cyclin A1 and directly regulates transcription. Mechanistic analyses showed that KDM8 functioned as a transcriptional activator by inhibiting HDAC recruitment via demethylation of H3K36me2, an epigenetic repressive mark. Tumor array experiments revealed KDM8 is overexpressed in several types of cancer. In addition, loss-of-function studies in MCF7 cells leads to cell cycle arrest. These studies identified KDM8 as an important cell cycle regulator.egulation of gene expression through posttranslational modification of the core histones has increasingly shown to be of great importance, particularly in a cancer setting. Among the multiple types of histone modifications, histone methylation, once considered irreversible, has quickly emerged to become a key epigenetic mark in regulating many critical cellular functions. The recent discovery of histone demethylases has shed light on the reversibility of this chromatin mark and its effects on gene expression. Studies exploring the JmjC (Jumonji C domain)-containing proteins, a newclass of histone demethylases (1-4), primarily identified their enzymatic activity at the promoters of specific target genes (5, 6).The JmjC domain-containing gene family encodes a wide range of the eukaryotic genome and is conserved in species spanning from yeast to humans. Currently, most family members classified as histone demethylases contain known histone-binding domains such as PHD and Tudor domains (7). JMJD5 (renamed KDM8) is a member of this extensive protein family that lacks recognizable histone-binding domains and remains largely unexplored. Although one study speculated that KDM8 acts as a potential tumor suppressor gene based on retrovirus insertional mutagenesis (8), no biological and molecular characterizations were described in the report.We extensively examine and provide evidence that KDM8 possesses H3K36me2 demethylase activity and has the ability to regulate cyclin A1 transcription in MCF7 breast cancer cells. We found that KDM8 is recruited to cyclin A1 coding region bound H3K36me2 and demethylates this mark, resulting in increased transcriptional activity. This finding is a departure from previous studies that showed that the majority of histone demethylases exert their epigenetic effects at the promoters of genes. Additionally, we describe overexpression of KDM8 in breast cancer tumors as well as its requirement for MCF7 cell cycle progression. ResultsJMJD5/KDM8 Is a H3K36me2 Demethylase. Our initial e...

JMJD5 regulates PKM2 nuclear translocation and reprograms HIF-1α–mediated glucose metabolism

“…Warburg effect | aerobic glycolysis | breast cancer | cancer metabolism J MJD5 is a Jumonji C domain-containing dioxygenase shown to be involved in lysine demethylation (1)(2)(3) and hydroxylation functions (4). Although the exact cellular substrates and functions of JMJD5 remain unclear, JMJD5 was shown to positively regulate cyclin A1 but negatively regulate p53 and p21 (1)(2)(3).…”

“…Although the exact cellular substrates and functions of JMJD5 remain unclear, JMJD5 was shown to positively regulate cyclin A1 but negatively regulate p53 and p21 (1)(2)(3). Knockdown of JMJD5 in Michigan Cancer Foundation (MCF)-7 cells inhibits cell proliferation (1), and JMJD5 −/− embryos showed severe growth retardation, resulting in embryonic lethality at the midgestation stage (3).…”

Depletion of JMJD5 sensitizes tumor cells to microtubule-destabilizing agents by altering microtubule stability

“…22,23 Huang and colleagues reported that a functional nuclear localization signal (NLS) and a nuclear export signal (NES) reside in the N-terminal domain of JMJD5. 38 JMJD5 localization is tightly regulated by Importin a/b-and transportin-1-mediated nuclear import and CRC1-dependent nuclear export, suggesting that JMJD5 translocation in and out of the nucleus may be associated with a novel function.…”

“…JMJD5 has been reported to suppress gene transcription through its histone H3K36me2 demethylase activity, 22,25 or positively promote gene transcription through binding to gene promoters. 32 To investigate if JMJD5 regulates the transcription of MAP1B, we evaluated MAP1B expression in JMJD5-depleted cells, JMJD5-overexpressing cells, and control cells using RT-real time PCR.…”

“…21 JMJD5 is a member of the JmjC domain-containing protein family, which has been shown to obtain H3K36me2 histone demethylase and hydroxylase activities. 22,23 JMJD5 was reported to function in multiple biological processes, including embryonic development, stem cell differentiation, osteoclastogenesis, circadian rhythm regulation, hepatitis B virus (HBV) replication, cell metabolism and cancer progression. [23][24][25][26][27][28][29][30][31][32] In addition, we previously reported that JMJD5 associated with the mitotic spindle and regulated mitotic spindle stability during mitosis.…”