RRC ID 52609
著者 Masuike Y, Tanaka K, Makino T, Yamasaki M, Miyazaki Y, Takahashi T, Kurokawa Y, Nakajima K, Mori M, Doki Y.
タイトル Esophageal squamous cell carcinoma with low mitochondrial copy number has mesenchymal and stem-like characteristics, and contributes to poor prognosis.
ジャーナル PLoS One
Abstract Alterations in mitochondrial DNA (mtDNA) copy numbers in various human cancers have been studied, but any such changes in esophageal squamous cell carcinoma (ESCC) are not established. In the present study, we investigated the correlation of mtDNA copy number with clinicopathologic features, prognosis, and malignant potential of ESCC. MtDNA copy numbers of resected specimens from 80 patients treated with radical esophagectomy were measured by quantitative real-time PCR analyses. Human ESCC cells, TE8 and TE11, were cultured, and depletion of mtDNA content was induced by knockdown of mitochondrial transcription factor A expression or treatment with ethidium bromide. The mRNA and protein expression, proliferation, invasion, and cell cycle were investigated. The results showed that the mtDNA copy number of cancerous portions was 56.0 (37.4-234.5) percent that of non-cancerous parts and significantly lower (p<0.01). Low mtDNA copy number in resected cancerous tissues was significantly correlated with pathological depth of tumor invasion (p = 0.045) and pathological stage (p = 0.025). Patients with lower mtDNA copy number had significantly poorer 5-year overall survival compared to patients with higher levels (p<0.01). The mtDNA-depleted TE8 and TE11 cells had morphological changes and proliferated more slowly than control cells under normoxia but proliferated at almost the same rate under hypoxic conditions. In mtDNA-depleted cells, E-cadherin mRNA expression was decreased, and N-cadherin, vimentin, zeb-1, and cd44 mRNA expression was increased. Immunoblotting and flow cytometry analysis also showed downregulated E-cadherin and upregulated N-cadherin and CD44 protein in mtDNA-depleted cells. Moreover, mtDNA-depleted cells had enhanced invasion, migration, and sphere formation abilities, and the cell cycle arrest at G0/G1 phase was induced in these cells. These results suggested that mtDNA-depleted ESCC cells had mesenchymal characteristics, cancer stemness, and tolerance to hypoxia, which played important role in cancer progression. In conclusion, a low copy number of mtDNA is associated with tumor progression in ESCC.
巻・号 13(2)
ページ e0193159
公開日 2018-2-15
DOI 10.1371/journal.pone.0193159
PII PONE-D-17-42450
PMID 29447301
PMC PMC5814088
MeSH Adult Aged Aged, 80 and over Carcinoma, Squamous Cell / metabolism Carcinoma, Squamous Cell / mortality Carcinoma, Squamous Cell / pathology* DNA Copy Number Variations* DNA, Mitochondrial* Esophageal Neoplasms / metabolism Esophageal Neoplasms / mortality Esophageal Neoplasms / pathology* Female Gene Expression Regulation, Neoplastic Humans Male Middle Aged Mitochondria / metabolism Mitochondria / pathology* Prognosis Survival Rate
IF 2.74
引用数 3
リソース情報
ヒト・動物細胞 TE-8(RCB2098) TE-11(RCB2100)