Human Cancer Biology IL-10 Promotes Tumor Aggressiveness via Upregulation of CIP 2 A Transcription in Lung Adenocarcinoma

Purpose: Interleukin-10 (IL-10) determines virus persistent infection and promotes viral-associated tumor progression via tumor immune escape. However, the role of IL-10 in tumor progression and prognosis in lung adenocarcinoma remains controversial. Experimental Design: To investigate how IL-10 is regulated by HPV E6, IL-10 promoter was constructed to understand which transcriptional factor could be responsible for its transcription. To verify which molecule could be responsible for IL-10–mediated soft agar growth and invasion capability, PCR array and mechanistic strategies were conducted. IL-10 and CIP2A mRNA levels in lung tumors from patients with lung cancer were determined by real-time reverse transcription PCR. The prognostic value of both molecules on survival was estimated by Cox regression model. Results: Mechanistic studies showed that IL-10 protein and mRNA expression was decreased in E6 knockdown TL1 cells and increased in E6overexpressing TL4 cells. In addition, IL-10 transcription was predominantly regulated by E6-mediated phosphorylation of cAMP response element-binding protein (CREB) and C/enhancer-binding protein b (C/EBPb) via phosphoinositide 3-kinase (PI3K) signaling pathway. IL-10–mediated tumor aggressiveness in vitro and in vivo occurs through increased CIP2A expression via PI3K signaling pathway. Among patients, IL-10 mRNA expression in lung tumors was positively correlated with CIP2A mRNA expression. Cox-regression analysis showed that IL-10 and CIP2A mRNA levels may independently predict survival in patients with lung adenocarcinoma, especially in patients with E6-positive tumors. Conclusion: IL-10 production from lung tumors and immune cells promotes lung adenocarcinoma aggressiveness and patients with poor survival. We thus suggest that PI3K inhibitor combined with chemotherapy may potentially enhance tumor regression and improve patients’ outcome and life quality. Clin Cancer Res; 19(15); 4092–103. 2013 AACR. Introduction Interleukin-10 (IL-10) belongs to TH2 cytokine for antiinflammation and it also inhibits T-cell immunity to block tumor immune surveillance (1–3). Most studies have indicated that IL-10 expression in immune cells, including macrophages, infiltrating T lymphocytes, and NK cells, promotes progression of tumors in kinds of cancer types including lung cancer (4, 5). In lung cancer cases, some reports have indicated that loss of IL-10 in lung tumorsmay promote tumor progression and result in poor clinical outcomes in patients; however, an opposite effect has been reported in other studies (6–8). Interestingly, the absence of IL-10 expression has been associated with poor outcome in stage I lung cancer, whereas in late-stage lung cancer, the presence of IL-10–positive macrophages at the tumor margins can be an indicator of poor prognosis (6–8). In addition, shorter survival times have been reported in patients with advanced lung cancerwhohadhigh serum IL-10 levels, when compared with similar patients who had low serum IL-10 levels (8). Therefore, the role of IL-10 in lung tumorigenesis remains elusive. The infection of human papillomavirus (HPV) 16/18 has been documented to associate with cancers of squamous epithelia.However, in Taiwan,HPV16/18 infection ratewas significantly higher in lung adenocarcinoma than in lung squamous cell carcinoma (9, 10). A highHPV infection rate in Taiwanese lung cancer reflects the possibility that imbalanced immune function might play an important role in Authors' Affiliations: School of Medicine, and Institute of Medicine; Divison of Chest Medicine, Department of Internal Medicine, and Department of Medical Research, Chung Shan Medical University Hospital; Department of Surgery, China Medical University Hospital, Taichung; and Graduate Institute of Cancer Biology and Drug Discovery, Taipei Medical University, Taipei, Taiwan, China Note: Supplementary data for this article are available at Clinical Cancer Research Online (http://clincancerres.aacrjournals.org/). W.W. Sung and Y.C. Wang contributed equally to this work. Corresponding Author: Huei Lee, Graduate Institute of Cancer Biology and Drug Discovery, Taipei Medical University, Room 5, 12F, No. 3, Park Street, Nankang District 115, Taipei, Taiwan. Phone: 886-2-2736-1661, ext. 7616; Fax: 886-2-2655-8562; E-mail: hl@tmu.edu. tw doi: 10.1158/1078-0432.CCR-12-3439 2013 American Association for Cancer Research. Clinical Cancer Research Clin Cancer Res; 19(15) August 1, 2013 4092 on May 28, 2017. © 2013 American Association for Cancer Research. clincancerres.aacrjournals. org Downloaded from Published OnlineFirst June 6, 2013; DOI: 10.1158/1078-0432.CCR-12-3439