title: Proteomic screening identifies calreticulin as a miR-27a direct target repressing MHC class I cell surface exposure in colorectal cancer.
abstract: Impairment of the immune response and aberrant expression of microRNAs are emerging hallmarks of tumour initiation/progression, in addition to driver gene mutations and epigenetic modifications. We performed a preliminary survey of independent adenoma and colorectal cancer (CRC) miRnoma data sets and, among the most dysregulated miRNAs, we selected miR-27a and disclosed that it is already upregulated in adenoma and further increases during the evolution to adenocarcinoma. To identify novel genes and pathways regulated by this miRNA, we employed a differential 2DE-DIGE proteome analysis. We showed that miR-27a modulates a group of proteins involved in MHC class I cell surface exposure and, mechanistically, demonstrated that calreticulin is a miR-27a direct target responsible for most downstream effects in epistasis experiments. In vitro miR-27a affected cell proliferation and angiogenesis; mouse xenografts of human CRC cell lines expressing different miR-27a levels confirmed the protein variations and recapitulated the cell growth and apoptosis effects. In vivo miR-27a inversely correlated with MHC class I molecules and calreticulin expression, CD8(+) T cells infiltration and cytotoxic activity (LAMP-1 exposure and perforin release). Tumours with high miR-27a, low calreticulin and CD8(+) T cells' infiltration were associated with distant metastasis and poor prognosis. Our data demonstrate that miR-27a acts as an oncomiRNA, represses MHC class I expression through calreticulin downregulation and affects tumour progression. These results may pave the way for better diagnosis, patient stratification and novel therapeutic approaches.
authors.affiliation: Department of Sciences and Technologies, University of Sannio, Benevento, Italy.
authors.forename: T
authors.initials: T
authors.lastname: Colangelo
authors.affiliation: Department of Sciences and Technologies, University of Sannio, Benevento, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Polcaro
authors.affiliation: Department of Sciences and Technologies, University of Sannio, Benevento, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Ziccardi
authors.affiliation: Centro Ricerche Oncologiche Mercogliano, Istituto Nazionale Tumori Fondazione G. Pascale-IRCCS, Mercogliano (AV), Italy.
authors.forename: B
authors.initials: B
authors.lastname: Pucci
authors.affiliation: Department of Sciences and Technologies, University of Sannio, Benevento, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Muccillo
authors.affiliation: Istituto di Endocrinologia e Oncologia Sperimentale, Consiglio Nazionale delle Ricerche (IEOS-CNR), Napoli, Italy.
authors.forename: M
authors.identifier: http://orcid.org/0000-0001-8414-1676
authors.initials: M
authors.lastname: Galgani
authors.affiliation: Department of Sciences and Technologies, University of Sannio, Benevento, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Fucci
authors.affiliation: Centro Ricerche Oncologiche Mercogliano, Istituto Nazionale Tumori Fondazione G. Pascale-IRCCS, Mercogliano (AV), Italy.
authors.forename: M R
authors.initials: MR
authors.lastname: Milone
authors.affiliation: Centro Ricerche Oncologiche Mercogliano, Istituto Nazionale Tumori Fondazione G. Pascale-IRCCS, Mercogliano (AV), Italy.
authors.forename: A
authors.initials: A
authors.lastname: Budillon
authors.affiliation: Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università di Napoli 'Federico II', Napoli, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Santopaolo
authors.affiliation: Department of Sciences and Technologies, University of Sannio, Benevento, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Votino
authors.affiliation: Department of Sciences and Technologies, University of Sannio, Benevento, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Pancione
authors.affiliation: Division of Epidemiology and Health Statistics, IRCCS-'Casa Sollievo della Sofferenza' Hospital, San Giovanni Rotondo (FG), Italy.
authors.forename: A
authors.initials: A
authors.lastname: Piepoli
authors.affiliation: Division of Internal Medicine and Chronobiology Unit, IRCCS-'Casa Sollievo della Sofferenza' Hospital, San Giovanni Rotondo (FG), Italy.
authors.forename: G
authors.initials: G
authors.lastname: Mazzoccoli
authors.affiliation: Department of Pharmacology, Menarini Ricerche, Pomezia (RM), Italy.
authors.forename: M
authors.initials: M
authors.lastname: Binaschi
authors.affiliation: Department of Pharmacology, Menarini Ricerche, Pomezia (RM), Italy.
authors.forename: M
authors.initials: M
authors.lastname: Bigioni
authors.affiliation: Menarini Ricerche, Florence, Italy.
authors.forename: C A
authors.initials: CA
authors.lastname: Maggi
authors.affiliation: Department of Pathology and Diagnostic, ARC-NET Research Centre, University of Verona, Verona, Italy.|Department of Medicine (DIMED), Surgical Pathology Unit, University of Padua, Padua, Italy.
authors.forename: M
authors.identifier: http://orcid.org/0000-0001-6515-5482
authors.initials: M
authors.lastname: Fassan
authors.affiliation: Department of Experimental and Clinical Medicine, Laboratory of Molecular Oncology, Magna Græcia University of Catanzaro, Catanzaro, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Laudanna
authors.affiliation: Istituto di Endocrinologia e Oncologia Sperimentale, Consiglio Nazionale delle Ricerche (IEOS-CNR), Napoli, Italy.|Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università di Napoli 'Federico II', Napoli, Italy.
authors.forename: G
authors.identifier: http://orcid.org/0000-0001-9429-0616
authors.initials: G
authors.lastname: Matarese
authors.affiliation: Department of Sciences and Technologies, University of Sannio, Benevento, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Sabatino
authors.affiliation: Department of Sciences and Technologies, University of Sannio, Benevento, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Colantuoni
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology; D000818:Animals; D017209:Apoptosis; D001483:Base Sequence; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D037282:Calreticulin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D015179:Colorectal Neoplasms / Q000401:mortality / Q000473:pathology / Q000628:therapy; D015536:Down-Regulation; D005260:Female; D045325:HCT116 Cells; D015395:Histocompatibility Antigens Class I / Q000378:metabolism; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D035683:MicroRNAs / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D009389:Neovascularization, Pathologic; D040901:Proteomics; D034622:RNA Interference; D016415:Sequence Alignment; D015854:Up-Regulation
chemical_list: D037282:Calreticulin; D015395:Histocompatibility Antigens Class I; D035683:MicroRNAs