title: Genome-wide in vivo RNAi screen identifies ITIH5 as a metastasis suppressor in pancreatic cancer.
abstract: The overwhelming majority of pancreatic ductal adenocarcinoma (PDAC) is not diagnosed until the cancer has metastasized, leading to an abysmal average life expectancy (3-6 months post-diagnosis). Earlier detection and more effective treatments have been hampered by inadequate understanding of the underlying molecular mechanisms controlling metastasis. We hypothesized that metastasis suppressors are involved in controlling metastasis in pancreatic cancer. Using an unbiased genome-wide shRNA screen, an shRNA library was transduced into the non-metastatic PDAC line S2-028 followed by intrasplenic injection. Resulting liver metastases were individually isolated from these mice. One liver metastatic nodule contained shRNA for ITIH5 (Inter-alpha-trypsin inhibitor heavy chain 5), suggesting that ITIH5 may act as a metastasis suppressor. Consistent with this notion, metastatic PDAC cell lines had significantly lower protein expression of ITIH5 compared to immortalized pancreatic ductal epithelial cells and non-/poorly-metastatic PDAC cell lines. By manipulating expression of ITIH5 in different PDAC cell lines (over-expression in metastatic, knockdown in non-metastatic) functional and selective regulation of metastasis was observed for ITIH5. Orthotopic tumor growth of PDAC cells was not blocked following orthotopic injection. In vitro ITIH5 over-expression inhibited motility and invasion. Immunohistochemical analysis of a human PDAC tissue microarray revealed that ITIH5 expression inversely correlated with both survival and invasion/metastasis. ITIH5 is, therefore, functionally validated as a PDAC metastasis suppressor and shows promise as a prognostic biomarker.
authors.affiliation: Department of Cancer Biology, The University of Kansas Medical Center, 3901 Rainbow Blvd, Mail Stop 1071, Kansas City, KS, 66160, USA.|Department of Digestive Surgery, Breast and Thyroid Surgery, Graduate School of Medical Sciences, Kagoshima University, 8-35-1, Sakuragaoka, Kagoshima, 890-8520, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Sasaki
authors.affiliation: Department of Cancer Biology, The University of Kansas Medical Center, 3901 Rainbow Blvd, Mail Stop 1071, Kansas City, KS, 66160, USA.|Department of Digestive Surgery, Breast and Thyroid Surgery, Graduate School of Medical Sciences, Kagoshima University, 8-35-1, Sakuragaoka, Kagoshima, 890-8520, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kurahara
authors.affiliation: Department of Cancer Biology, The University of Kansas Medical Center, 3901 Rainbow Blvd, Mail Stop 1071, Kansas City, KS, 66160, USA.|Department of Digestive Surgery, Breast and Thyroid Surgery, Graduate School of Medical Sciences, Kagoshima University, 8-35-1, Sakuragaoka, Kagoshima, 890-8520, Japan.
authors.forename: Eric D
authors.initials: ED
authors.lastname: Young
authors.affiliation: Department of Digestive Surgery, Breast and Thyroid Surgery, Graduate School of Medical Sciences, Kagoshima University, 8-35-1, Sakuragaoka, Kagoshima, 890-8520, Japan.
authors.forename: Shoji
authors.initials: S
authors.lastname: Natsugoe
authors.affiliation: Department of Digestive Surgery, Breast and Thyroid Surgery, Graduate School of Medical Sciences, Kagoshima University, 8-35-1, Sakuragaoka, Kagoshima, 890-8520, Japan.
authors.forename: Asami
authors.initials: A
authors.lastname: Ijichi
authors.affiliation: Department of Cancer Biology, The University of Kansas Medical Center, 3901 Rainbow Blvd, Mail Stop 1071, Kansas City, KS, 66160, USA. tiwakuma@kumc.edu.|The University of Kansas Cancer Center, 3901 Rainbow Blvd, Kansas City, KS, 66160, USA. tiwakuma@kumc.edu.|Department of Digestive Surgery, Breast and Thyroid Surgery, Graduate School of Medical Sciences, Kagoshima University, 8-35-1, Sakuragaoka, Kagoshima, 890-8520, Japan. tiwakuma@kumc.edu.
authors.forename: Tomoo
authors.initials: T
authors.lastname: Iwakuma
authors.affiliation: Department of Cancer Biology, The University of Kansas Medical Center, 3901 Rainbow Blvd, Mail Stop 1071, Kansas City, KS, 66160, USA. dwelch@kumc.edu.|The University of Kansas Cancer Center, 3901 Rainbow Blvd, Kansas City, KS, 66160, USA. dwelch@kumc.edu.|Department of Digestive Surgery, Breast and Thyroid Surgery, Graduate School of Medical Sciences, Kagoshima University, 8-35-1, Sakuragaoka, Kagoshima, 890-8520, Japan. dwelch@kumc.edu.
authors.forename: Danny R
authors.identifier: 0000-0002-1951-4947
authors.initials: DR
authors.lastname: Welch
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D017209:Apoptosis; D014408:Biomarkers, Tumor / Q000235:genetics; D049109:Cell Proliferation; D005260:Female; D005500:Follow-Up Studies; D015972:Gene Expression Regulation, Neoplastic; D015894:Genome, Human; D057166:High-Throughput Screening Assays; D006801:Humans; D008113:Liver Neoplasms / Q000235:genetics / Q000517:prevention & control* / Q000556:secondary / Q000601:surgery; D008297:Male; D051379:Mice; D008819:Mice, Nude; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D010190:Pancreatic Neoplasms / Q000235:genetics / Q000473:pathology / Q000517:prevention & control* / Q000601:surgery; D011379:Prognosis; D011401:Promoter Regions, Genetic; D053491:Proteinase Inhibitory Proteins, Secretory / Q000037:antagonists & inhibitors / Q000235:genetics*; D034741:RNA, Small Interfering / Q000235:genetics*; D015996:Survival Rate; D014407:Tumor Cells, Cultured; D023041:Xenograft Model Antitumor Assays
chemical_list: D014408:Biomarkers, Tumor; C482680:ITIH5 protein, human; D053491:Proteinase Inhibitory Proteins, Secretory; D034741:RNA, Small Interfering
keywords: ITIH5; Metastasis suppressor; Pancreatic cancer; RNAi screen