title: Overexpression of HP1γ is associated with poor prognosis in non-small cell lung cancer cell through promoting cell survival.
abstract: Heterochromatin protein 1γ (HP1γ), which binds to di- or trimethylated lysine 9 on histone H3 (H3K9), plays an important role in chromatin packaging and gene transcriptional regulation. Recently, HP1γ has been implicated in cancer development. However, its clinical relevance and functional role in non-small cell lung cancer (NSCLC) remain elusive. In this study, we found that HP1γ expression was elevated in NSCLC samples at the messenger RNA (mRNA) level compared to adjacent normal lung tissues. In a cohort of 108 NSCLC patients, HP1γ overexpression is significantly associated with N stage (P = 0.003), pathological tumor-node-metastasis (TNM) stage (P = 0.013), smoking status (P = 0.009), and gender (P = 0.042). Patients with a high level of HP1γ expression showed a poorer overall survival rate than those with low HP1γ expression (P = 0.017). Multivariate analysis revealed that HP1γ expression is an independent prognostic marker. We also found knockdown of HP1γ in A549 and NCI-H1975 cells induced apoptosis accompanied with suppressed cell proliferation and colony formation. Consistently, pro-apoptotic proteins, Bax and GADD45α, were upregulated in response to HP1γ depletion. Altogether, our data suggested that HP1γ plays an important role in promoting NSCLC and may represent a novel prognostic biomarker and therapeutic target for the disease.
authors: Department of Respiratory Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, Jiangsu, China.
authors: Ji
authors: J
authors: Zhou
authors: Hui
authors: H
authors: Bi
authors: Ping
authors: P
authors: Zhan
authors: Cunjie
authors: C
authors: Chang
authors: Chunhua
authors: C
authors: Xu
authors: Xiaojing
authors: X
authors: Huang
authors: Like
authors: L
authors: Yu
authors: Xin
authors: X
authors: Yao
authors: Jun
authors: J
authors: Yan
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis*; D015153:Blotting, Western; D002289:Carcinoma, Non-Small-Cell Lung / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D002470:Cell Survival; D000090266:Chromobox Protein Homolog 5; D002868:Chromosomal Proteins, Non-Histone / Q000032:analysis / Q000096:biosynthesis*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D053208:Kaplan-Meier Estimate; D008175:Lung Neoplasms / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection; D015854:Up-Regulation
chemical_list: D014408:Biomarkers, Tumor; D002868:Chromosomal Proteins, Non-Histone; D000090266:Chromobox Protein Homolog 5