Mutation and expression analysis of the IDH1, IDH2, DNMT3A, and MYD88 genes in colorectal cancer
Introduction
Colorectal cancer (CRC) is one of the most prevalent cancers throughout the world with a 5-year survival rate of 30–65% and it affects men and women almost equally (Haggar and Boushey, 2009, Savas and Younghusband, 2010). Although the incidence of CRC has stabilized and/or declined gradually in the last 30 years in parts of Europe and the United States, the incidence is increasing rapidly in some Asian countries such as China, Japan, and Singapore, among others (Haggar and Boushey, 2009, Jemal et al., 2008). Ulcerative colitis (UC), familial adenomatous polyposis (FAP), and hereditary nonpolyposis cancer (HNPCC) constituted the top three high-risk factors for the development of CRC (Kaluz and Van Meir, 2011). During the past decades, a series of genes, including APC, TP53, and KRAS, was identified to be altered in CRC (Kaluz and Van Meir, 2011). Among them, genes involved in the EGFR signal pathway (KRAS, BRAF, and APC) are the most frequently mutated in CRC patients. However, there is still a large portion of CRC cases that do not contain mutations in these canonical oncogenes and tumor-suppressor genes, and the molecular underpinnings of CRC have not been clearly elucidated (Aissi et al., 2013).
Recent genome-wide association studies and/or whole-exome sequencing analyses in different cancers have led to the identification of many non-canonical candidate oncogenes, i.e., IDH1/2, MYD88, SF3B1, and MAP2K1/2 (Mardis et al., 2009, Ngo et al., 2011, Nikolaev et al., 2012, Parsons et al., 2008, Puente et al., 2011, Quesada et al., 2012). Foremost among the list are isocitrate dehydrogenase 1 (IDH1) and isocitrate dehydrogenase 2 (IDH2), which are frequently mutated in glioblastoma and several kinds of myeloid malignancies (Gross et al., 2010, Ichimura et al., 2009, Mardis et al., 2009, Zou et al., 2010). The most important mutations in these two genes are IDH1 p.R132, IDH2 p.R140, and IDH2 p.R172 that are located in the active site of the enzymes (Xu et al., 2004, Yan et al., 2009). Subsequent investigations discovered that these mutants promote the production of 2-hydroxyglutarate (2-HG) (Figueroa et al., 2010, Xu et al., 2011). The increased level of 2-HG could result in genome-wide histone and DNA methylation alterations, which have been proven to play active roles in the development of cancer (Figueroa et al., 2010, Jia and Guo, 2013, Kondo and Issa, 2004, Xu et al., 2011). Although the first IDH1 mutation was identified in a CRC patient and the gain-of-function mutation was also validated in colorectal cell lines, there has been no other IDH1 mutation reported in colorectal cancer thus far (Jin et al., 2013, Sjoblom et al., 2006, Yen et al., 2010). Another gene involved in DNA methylation, DNA methyltransferase 3A (DNMT3A), was found to be associated with colorectal cell proliferation, apoptosis, and senescence (Ng et al., 2009, Zhang et al., 2011). A series of functional mutations in the coding region of DNMT3A was identified in acute myeloid leukemia (AML), but the mutation status and expression level of this gene in CRC and its relevance to CRC pathogenesis is still unknown (Ley et al., 2010, Lin et al., 2011, Yan et al., 2011).
MYD88 is a key adaptor mediating the signal transduction from Toll-like receptor (TLR) and interleukin 1 receptor (IL-1R) family members (Han, 2006). Activation of MYD88 could give rise to multiple downstream signaling cascades including nuclear factor-kappa B (NF-κB) signal pathway, which plays a crucial role in pathogenesis of CRC through suppression of apoptosis, induction of epithelial growth, promotion of angiogenesis, and cancerous cell invasion (Wang et al., 2009). Recently, two groups independently identified that mutation p.L265P in the MYD88 gene is a recurrent mutation in human lymphoma (29%) and chronic lymphocytic leukemia (2.9%) (Ngo et al., 2011, Puente et al., 2011). Several cancer-associated signaling pathways (including NF-κB) are activated in the presence of MYD88 mutation (Ngo et al., 2011, Puente et al., 2011). However, whether the increased NF-κB activity in CRC could be attributed to the MYD88 p.L265P mutation has not been analyzed.
To investigate whether the four genes IDH1, IDH2, DNMT3A, and MYD88 are actively involved in the development of CRC, we analyzed the reported pathogenic mutations of these genes in 305 CRC patients and quantified the mRNA levels of these four genes in paired cancerous and paracancerous normal tissues from 65 patients in this study. No hotspot mutations were identified except for an IDH1 mutation p.I99M. Decreased mRNA expression of IDH1, DNMT3A, and MYD88 were identified in cancerous tissues. These results suggested that aberrant mRNA expression of IDH1, DNMT3A, and MYD88 genes might be associated with the onset and/or development of CRC.
Section snippets
Patients
305 patients were collected at the First Affiliated Hospital of Kunming Medical University from 2010 to 2011. All patients were histopathologically confirmed to have CRC by two pathologists independently. The colorectal cancer staging was determined according to the TNM (Tumor, Node, Metastasis) system. The TNM system assigns a number based on three categories. “T” denotes the degree of invasion of the intestinal wall, “N” denotes the degree of lymphatic node involvement, and “M” denotes the
Mutation status of IDH1–R132, IDH2–R140/R172, DNMT3A–R882, and MYD88–L265P in CRC samples
We analyzed the mutation status in exon 4 of IDH1 (for R132) and IDH2 (for R140 and R172), exon 23 of DNMT3A (for R882), and exon 5 of MYD88 (for p.L265P) in 305 CRC patients by direct sequencing. A heterozygous p.I99M mutation in the IDH1 gene was identified in one CRC patient. This mutation was observed in cancerous tissue, paracancerous tissue, and paracancerous normal tissue of the patient (Fig. 1a), suggesting that it is unlikely to be somatic. We did not find any of the reported hotspot
Discussion
The pathogenesis of CRC is an intricate and multi-step processes regulated by intrinsic and extrinsic factors, including genetics, age, diet, population and lifestyle (Chan and Giovannucci, 2010, Haggar and Boushey, 2009). Great achievements have been made in deciphering the genetic mechanisms of CRC onset, and a relatively limited number of the most prominent oncogenes and tumor-suppressor genes were identified over the past 30 years (Fearon, 2011). There has been insufficient study showing
Conflict of interest
The authors declare that they have no conflict of interest.
Acknowledgments
We thank Miss Sarah J. McAnulty for the language editing and Dr. Yunlong Li, Miss Le Chang, Mr. Yong-Sheng Du and Mr. Yue Pan for the technical assistance. This study was supported by Chinese Academy of Sciences and Yunnan Province (2009CI119).
References (55)
- et al.
Leukemic IDH1 and IDH2 mutations result in a hypermethylation phenotype, disrupt TET2 function, and impair hematopoietic differentiation
Cancer Cell
(2010) - et al.
MyD88 and its divergent toll in carcinogenesis
Trends Immunol.
(2013) - et al.
The common feature of leukemia-associated IDH1 and IDH2 mutations is a neomorphic enzyme activity converting alpha-ketoglutarate to 2-hydroxyglutarate
Cancer Cell
(2010) - et al.
Structures of human cytosolic NADP-dependent isocitrate dehydrogenase reveal a novel self-regulatory mechanism of activity
J. Biol. Chem.
(2004) - et al.
Oncometabolite 2-hydroxyglutarate is a competitive inhibitor of alpha-ketoglutarate-dependent dioxygenases
Cancer Cell
(2011) - et al.
IDH1 and IDH2 mutations are frequent in Chinese patients with acute myeloid leukemia but rare in other types of hematological disorders
Biochem. Biophys. Res. Commun.
(2010) - et al.
KRAS mutations in colorectal cancer from Tunisia: relationships with clinicopathologic variables and data on TP53 mutations and microsatellite instability
Mol. Biol. Rep.
(2013) - et al.
Analysis of the IDH1 codon 132 mutation in brain tumors
Acta Neuropathol.
(2008) - et al.
Regions of focal DNA hypermethylation and long-range hypomethylation in colorectal cancer coincide with nuclear lamina-associated domains
Nat. Genet.
(2012) - et al.
IDH1 mutations at residue p.R132 (IDH1(R132)) occur frequently in high-grade gliomas but not in other solid tumors
Hum. Mutat.
(2009)
Primary prevention of colorectal cancer
Gastroenterology
Molecular alterations of isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) metabolic genes and additional genetic mutations in newly diagnosed acute myeloid leukemia patients
J. Hematol. Oncol.
Cancer-associated IDH1 mutations produce 2-hydroxyglutarate
Nature
Molecular genetics of colorectal cancer
Annu. Rev. Pathol.
Deletion of the de novo DNA methyltransferase Dnmt3a promotes lung tumor progression
Proc. Natl. Acad. Sci. U. S. A.
Cancer-associated metabolite 2-hydroxyglutarate accumulates in acute myelogenous leukemia with isocitrate dehydrogenase 1 and 2 mutations
J. Exp. Med.
Colorectal cancer epidemiology: incidence, mortality, survival, and risk factors
Clin. Colon Rectal Surg.
MyD88 beyond Toll
Nat. Immunol.
Mutations of IDH1 and IDH2 are not detected in brain metastases of colorectal cancer
J. Neurooncol.
The expression and significance of IDH1 and p53 in osteosarcoma
J. Exp. Clin. Cancer Res.
IDH1 mutations are present in the majority of common adult gliomas but rare in primary glioblastomas
Neuro. Oncol.
Mutational and expressional analyses of MYD88 gene in common solid cancers
Tumori
Annual report to the nation on the status of cancer, 1975–2005, featuring trends in lung cancer, tobacco use, and tobacco control
J. Natl. Cancer Inst.
Epigenetic changes in colorectal cancer
Chin. J. Cancer
Disruption of wild-type IDH1 suppresses D-2-hydroxyglutarate production in IDH1-mutated gliomas
Cancer Res.
At the crossroads of cancer and inflammation: Ras rewires an HIF-driven IL-1 autocrine loop
J. Mol. Med. (Berl.)
Mutational analysis of IDH1 codon 132 in glioblastomas and other common cancers
Int. J. Cancer
Cited by (19)
Prognostic significance of DNMT3A alterations in Middle Eastern papillary thyroid carcinoma
2019, European Journal of CancerCitation Excerpt :Previously, The Cancer Genome Atlas reported that DNMT3A was recurrently mutated in PTCs [13]. Several studies have highlighted the importance of DNMT3A alterations in other solid tumours such as lung, colorectal and ovarian cancers [14–16]. Guo et al. [17] have also demonstrated DNMT3A mutations to be enriched in poorly differentiated and anaplastic thyroid cancers and associated with poor survival.
Dual functional roles of the MyD88 signaling in colorectal cancer development
2018, Biomedicine and PharmacotherapyCitation Excerpt :In human, MyD88 mutation, leading to a change in the amino acid from leucine to proline at the position 265 was reported to associate with lymphoma development [11] and thereafter, altered MyD88 and the MyD88-related signaling were shown to involve in cancer-associated cell intrinsic and extrinsic inflammation progression and carcinogenesis. Moreover, detection of aberrant MyD88 expression was used to predict prognosis of various human cancers, e.g., lymphoid [12], liver [13], and colorectal [14] cancers. Indeed, the role of inflammation in cancer progression depends on the activation of innate receptors by microbe or the endogenous ligands by TLRs and IL1Rs via MyD88 [15–17].
Deleting MyD88 signaling in myeloid cells promotes development of adenocarcinomas of the colon
2018, Cancer LettersCitation Excerpt :Eun Mi Je analyzed MyD88 protein expression in 60 coloretal carcinomas, and observed that lower MyD88 expression in colorectal cancer cells (80%) than in normal colorectal cells (100%) according to immunohistochemistry analysis [33]. Wen-Liang Li also noticed that MyD88mRNA expression levels were significantly reduced in patients' cancerous tissues [34]. These data suggested that down regulated expression level of MyD88 maybe involved in promoting human CRC, which is in lined with our experimental results here.
IDH mutations associated impact on related cancer epidemiology and subsequent effect toward HIF-1α
2017, Biomedicine and PharmacotherapyCitation Excerpt :Nevertheless, the predictive value of MGMT promoter methylation for chemosensitivity in grade 2 and grade 3 glioma is not well established even controversial; methylation of the MGMT gene promoter is usually associated with IDH1 and IDH2 mutations and seems to predict a better prognosis for patients [23–26]. Glioma patients with IDH mutations live longer compared to patients with wild-type IDH, and multivariable analyses proves IDH1 mutation status is an independent positive prognostic factor for glioblastomas [7], but in a previous study in multiple solid cancers, was identified an IDH1 p.G97D mutation, which is also located in the isocitrate binding active region, suggesting that mutations in this region may have a harmful effect [27,28]. Clinical connection to IDH mutations in glioma consist of younger age, longer survival and reduced risk of disease progression after therapy [14].