Antiapoptotic activity of autocrine interleukin-22 and therapeutic effects of interleukin-22-small interfering RNA on human lung cancer xenografts

Clin Cancer Res. 2008 Oct 15;14(20):6432-9. doi: 10.1158/1078-0432.CCR-07-4401.


Purpose: Non-small cell lung carcinoma (NSCLC) is one of most common malignant diseases and usually is resistant against apoptosis-inducing chemotherapy. This study is to explore the antiapoptotic mechanisms of interleukin (IL)-22 in human lung cancer.

Experimental design: Nineteen cases with stage I to III NSCLC were collected to determine the expression of IL-22. Stable transfection of human IL-22 cDNA into A549 and PG cells and transfection of IL-22-RNA interference (RNAi) into these cancer cell lines were done to reveal the molecular mechanisms of IL-22.

Results: It was found that IL-22 was highly expressed in primary tumor tissue, malignant pleural effusion, and serum of patients with NSCLC. IL-22R1 mRNA was also detected in lung cancer tissues as well as lung cancer cell lines. Overexpression of IL-22 protected lung cancer cell lines from serum starvation-induced and chemotherapeutic drug-induced apoptosis via activation of STAT3 and its downstream antiapoptotic proteins such as Bcl-2 and Bcl-xL and inactivation of extracellular signal-regulated kinase 1/2. Exposure to blocking antibodies against IL-22R1 or transfection with the IL-22-RNAi plasmid in vitro resulted in apoptosis of these lung cancer cells via STAT3 and extracellular signal-regulated kinase 1/2 pathways. Furthermore, an in vivo xenograft study showed that administration of IL-22-RNAi plasmids significantly inhibited the human tumor cell growth in BALB/c nude mice.

Conclusions: Our study indicates that autocrine production of IL-22 contributes to human lung cancer cell survival and resistance to chemotherapy through the up-regulation of antiapoptotic proteins.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenocarcinoma / genetics
  • Adenocarcinoma / pathology
  • Adenocarcinoma / therapy
  • Animals
  • Apoptosis / drug effects*
  • Blotting, Western
  • Carcinoma, Non-Small-Cell Lung / genetics
  • Carcinoma, Non-Small-Cell Lung / pathology
  • Carcinoma, Non-Small-Cell Lung / therapy
  • Carcinoma, Squamous Cell / genetics
  • Carcinoma, Squamous Cell / pathology
  • Carcinoma, Squamous Cell / therapy
  • Case-Control Studies
  • Caspases / metabolism
  • Cell Proliferation
  • Humans
  • Immunoenzyme Techniques
  • Interleukins / genetics*
  • Lung / metabolism
  • Lung / pathology
  • Lung Neoplasms / genetics
  • Lung Neoplasms / pathology
  • Lung Neoplasms / therapy*
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Mice, Nude
  • Mitogen-Activated Protein Kinase 1 / metabolism
  • Mitogen-Activated Protein Kinase 3 / metabolism
  • Pleural Effusion, Malignant / genetics
  • Pleural Effusion, Malignant / pathology
  • Pleural Effusion, Malignant / therapy
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • RNA, Small Interfering / therapeutic use*
  • Receptors, Interleukin / genetics
  • Receptors, Interleukin / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • STAT3 Transcription Factor / metabolism
  • Transplantation, Heterologous
  • Tumor Cells, Cultured


  • Interleukins
  • RNA, Messenger
  • RNA, Small Interfering
  • Receptors, Interleukin
  • STAT3 Transcription Factor
  • interleukin-22 receptor
  • Mitogen-Activated Protein Kinase 1
  • Mitogen-Activated Protein Kinase 3
  • Caspases
  • interleukin-22