title: Epigenetic deregulation of the anaplastic lymphoma kinase gene modulates mesenchymal characteristics of oral squamous cell carcinomas.
abstract: DNA hypermethylation of promoter CpG islands is associated with epigenetic silencing of tumor suppressor genes in oral squamous cell carcinomas (OSCCs). We used a methyl-CpG-binding domain protein capture method coupled with next-generation sequencing (MBDCap-seq) to survey global DNA methylation patterns in OSCCs with and without nodal metastasis and normal mucosa (total n = 58). Of 1462 differentially methylated CpG islands identified in OSCCs relative to normal controls, MBDCap-seq profiling uncovered 359 loci linked to lymph node metastasis. Interactive network analysis revealed a subset of these loci (n = 23), including the anaplastic lymphoma kinase (ALK) gene, are potential regulators and effectors of invasiveness and metastatic progression. Promoter methylation of ALK was preferentially observed in OSCCs without node metastasis, whereas relatively lower methylation levels were present in metastatic tumors, implicating an active state of ALK transcription in the latter group. The OSCC cell line, SCC4, displayed reduced ALK expression that corresponded to extensive promoter CpG island methylation. SCC4 treatment with demethylating agents induced ALK expression and increased invasion and migration characteristics. Inhibition of ALK activity in OSCC cells with high ALK expression (CAL27, HSC3 and SCC25), decreased cell growth and resulted in changes in invasive potential and mesenchymal marker expression that were cell-line dependent. Although ALK is susceptible to epigenetic silencing during oral tumorigenesis, overwriting this default state may be necessary for modulating invasive processes involved in nodal metastases. Given the complex response of OSCC cells to ALK inhibition, future studies are required to assess the feasibility of targeting ALK to treat invasive OSCCs.
authors.affiliation: Cancer Therapy and Research Center, University of Texas Health Science Center at San Antonio, TX 78229, USA. huangt3@uthscsa.edu
authors.forename: Tze-Ta
authors.initials: TT
authors.lastname: Huang
authors.forename: Cara B
authors.initials: CB
authors.lastname: Gonzales
authors.forename: Fei
authors.initials: F
authors.lastname: Gu
authors.forename: Ya-Ting
authors.initials: YT
authors.lastname: Hsu
authors.forename: Rohit R
authors.initials: RR
authors.lastname: Jadhav
authors.forename: Chiou-Miin
authors.initials: CM
authors.lastname: Wang
authors.forename: Spencer W
authors.initials: SW
authors.lastname: Redding
authors.forename: Chih-En
authors.initials: CE
authors.lastname: Tseng
authors.forename: Ching-Chih
authors.initials: CC
authors.lastname: Lee
authors.forename: Ian M
authors.initials: IM
authors.lastname: Thompson
authors.forename: Hau-Ren
authors.initials: HR
authors.lastname: Chen
authors.forename: Tim Hui-Ming
authors.initials: TH
authors.lastname: Huang
authors.forename: Nameer B
authors.initials: NB
authors.lastname: Kirma
mesh_terms: D000077548:Anaplastic Lymphoma Kinase; D063646:Carcinogenesis / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D048708:Cell Growth Processes / Q000502:physiology; D045744:Cell Line, Tumor; D018899:CpG Islands; D019175:DNA Methylation; D018450:Disease Progression; D044127:Epigenesis, Genetic; D006801:Humans; D008207:Lymphatic Metastasis; D008648:Mesoderm / Q000378:metabolism / Q000473:pathology*; D009061:Mouth Mucosa / Q000378:metabolism / Q000473:pathology; D009062:Mouth Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D009361:Neoplasm Invasiveness; D011401:Promoter Regions, Genetic; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics* / Q000378:metabolism; D015533:Transcriptional Activation
chemical_list: C000626173:ALK protein, human; D000077548:Anaplastic Lymphoma Kinase; D020794:Receptor Protein-Tyrosine Kinases