title: Inhibition of autophagy by 3-MA enhances IL-24-induced apoptosis in human oral squamous cell carcinoma cells.
abstract: BACKGROUND
  Interleukin-24(IL-24), also referred to as melanoma differentiation-associated gene-7(mda-7), is a unique member of the IL-10 gene family, which displays nearly ubiquitous cancer-specific toxicity. The most notable feature of IL-24 is selectively induced growth suppression and apoptosis in various cancer cells, with no harmful effects toward normal cells. Autophagy is a self-protective mechanism in many kinds of tumor cells that respond to anticancer treatment. It is reported that autophagy inhibition could enhance the effects of many kinds of anticancer treatments, including gene therapy. However, whether IL-24 is effective to treat oral squamous cell carcinomas (OSCC) and if autophagy inhibition could improve the anticancer effect of IL-24 towards OSCC is has not been detected.
  
  
  METHODS
  MTT assays were carried out to determine the cell proliferation; Transfection was used to gene transfer; Western Blot was performed to detect the protein level of LC3II, P62, Beclin 1, Cleaved caspase-3, β-Tubulin and β-actin; Apoptosis rates and cell cycle alteration were analyzed using flow cytometry; Autophagy induction was confirmed by MDC staining, GFP-LC3 staining and transmission electron microscopy. Amount of IL-24 in the culture medium was quantified by ELISA. Apoptosis in vivo was analyzed by TUNEL assay. HE staining was used to observe the morphology of the samples.
  
  
  RESULTS
  In the present study, we proved that IL-24 have a novel anticancer effect towards KB cells and that autophagy inhibition could improve the anticancer effect of IL-24. IL-24 treated cells showed autophagy characteristics and autophagy inhibition by 3-methyladenine (3-MA) significantly enhanced IL-24-induced apoptosis. Similar results were obtained in the KB cells xenograft tumor model.
  
  
  CONCLUSIONS
  These results suggest that the combination of autophagy inhibitors and IL-24 based on the AdLTR2EF1α-mediated gene transfer could be a promising way to cure OSCC.
authors.affiliation: School of Life Science and Technology, Harbin Institute of Technology, 2 Yikuang Street, Harbin, 150001, People's Republic of China. lijichen@163.com.
authors.forename: Jichen
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Dentistry, Harbin Medical University, 141 Yiman Street, Nangang District, Harbin, 150001, People's Republic of China. 264706737@163.com.
authors.forename: Dezhao
authors.initials: D
authors.lastname: Yang
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Dentistry, Harbin Medical University, 141 Yiman Street, Nangang District, Harbin, 150001, People's Republic of China. wangwei123www@126.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Dentistry, Harbin Medical University, 141 Yiman Street, Nangang District, Harbin, 150001, People's Republic of China. spiao@umich.edu.
authors.forename: Songlin
authors.initials: S
authors.lastname: Piao
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Dentistry, Harbin Medical University, 141 Yiman Street, Nangang District, Harbin, 150001, People's Republic of China. zjyhmu@126.com.
authors.forename: Jianyu
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Dentistry, Harbin Medical University, 141 Yiman Street, Nangang District, Harbin, 150001, People's Republic of China. 1208401803@qq.com.
authors.forename: Wuliji
authors.initials: W
authors.lastname: Saiyin
authors.affiliation: National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA. czheng@dir.nidcr.nih.gov.
authors.forename: Changyu
authors.initials: C
authors.lastname: Zheng
authors.affiliation: Department of Oral Pathology, School of Stomatology, Jilin University, 1500 Qinghua Road, Changchun, 130021, People's Republic of China. hcsun@mail.jlu.edu.cn.
authors.forename: Hongchen
authors.initials: H
authors.lastname: Sun
authors.affiliation: School of Life Science and Technology, Harbin Institute of Technology, 2 Yikuang Street, Harbin, 150001, People's Republic of China. liyugene@hit.edu.cn.
authors.forename: Yu
authors.initials: Y
authors.lastname: Li
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis; D001343:Autophagy / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002470:Cell Survival; D015870:Gene Expression; D015316:Genetic Therapy; D006801:Humans; D007378:Interleukins / Q000502:physiology*; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009062:Mouth Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000628:therapy; D018307:Neoplasms, Squamous Cell / Q000378:metabolism / Q000473:pathology* / Q000628:therapy; D014162:Transfection; D047368:Tumor Burden; D023041:Xenograft Model Antitumor Assays; D000099180:Interleukin-24
chemical_list: D000225:Adenine; D000970:Antineoplastic Agents; D007378:Interleukins; D000099180:Interleukin-24; C025946:3-methyladenine