title: Spinophilin expression determines cellular growth, cancer stemness and 5-flourouracil resistance in colorectal cancer.
abstract: The putative tumor suppressor gene spinophilin has been involved in cancer progression in several types of cancer. In this study, we explored the prognostic value of spinophilin expression in 162 colon adenocarcinoma patients. In addition, we generated stably expressing spinophilin-directed shRNA CRC cell lines and studied the influence of spinophilin expression on cellular phenotypes and molecular interactions. We independently confirmed that low spinophilin expression levels are associated with poor prognosis in CRC patients (p = 0.038). A reduction of spinophilin levels in p53 wild-type HCT116 and p53-mutated Caco-2 cells led to increased cellular growth rates and anchorage-independent growth (p<0.05). At molecular level, reduced spinophilin levels increased the expression of the transcription factor E2F-1. In addition, we observed an increased formation of tumor spheres, increased number of CD133 positive cells and an increased resistance to 5-flourouracil (p<0.05). Finally, treatment with the de-methylating agent 5-aza-dC increased spinophilin expression in CRC cells (p<0.05), corroborated by a correlation of spinophilin expression and extent of methylated CpG sites in the gene promoter region (p<0.001). In conclusion, gain of aggressive biological properties of CRC cells including cellular growth, cancer stem cell features and 5-flourouracil resistance partly explains the role of spinophilin in CRC.
authors.affiliation: Division of Oncology, Department of Internal Medicine, Medical University of Graz, Austria. These authors contributed equally to this work.
authors.forename: Anna Lena
authors.initials: AL
authors.lastname: Ress
authors.affiliation: Division of Oncology, Department of Internal Medicine, Medical University of Graz, Austria. These authors contributed equally to this work.
authors.forename: Verena
authors.initials: V
authors.lastname: Stiegelbauer
authors.affiliation: Division of Oncology, Department of Internal Medicine, Medical University of Graz, Austria.
authors.forename: Daniela
authors.initials: D
authors.lastname: Schwarzenbacher
authors.affiliation: Division of Haematology, Department of Internal Medicine, Medical University of Graz, Austria.
authors.forename: Alexander
authors.initials: A
authors.lastname: Deutsch
authors.affiliation: Division of Oncology, Department of Internal Medicine, Medical University of Graz, Austria.
authors.forename: Samantha
authors.initials: S
authors.lastname: Perakis
authors.affiliation: Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, TX, USA.
authors.forename: Hui
authors.initials: H
authors.lastname: Ling
authors.affiliation: Center for RNA Interference and Non-Coding RNAs, The University of Texas MD Anderson Cancer Center, TX, USA.
authors.forename: Cristina
authors.initials: C
authors.lastname: Ivan
authors.affiliation: Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, TX, USA. Center for RNA Interference and Non-Coding RNAs, The University of Texas MD Anderson Cancer Center, TX, USA.
authors.forename: George Adrian
authors.initials: GA
authors.lastname: Calin
authors.affiliation: Center for Medical Research, Medical University of Graz, Graz, Austria.
authors.forename: Beate
authors.initials: B
authors.lastname: Rinner
authors.affiliation: Division of Oncology, Department of Internal Medicine, Medical University of Graz, Austria.
authors.forename: Armin
authors.initials: A
authors.lastname: Gerger
authors.affiliation: Division of Oncology, Department of Internal Medicine, Medical University of Graz, Austria. Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, TX, USA.
authors.forename: Martin
authors.initials: M
authors.lastname: Pichler
mesh_terms: D000071916:AC133 Antigen; D000230:Adenocarcinoma / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism / Q000401:mortality / Q000473:pathology; D015703:Antigens, CD / Q000378:metabolism; D000964:Antimetabolites, Antineoplastic / Q000627:therapeutic use*; D018938:Caco-2 Cells; D049109:Cell Proliferation / Q000187:drug effects*; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism / Q000401:mortality / Q000473:pathology; D018899:CpG Islands / Q000187:drug effects; D019175:DNA Methylation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D019008:Drug Resistance, Neoplasm; D050687:E2F1 Transcription Factor / Q000378:metabolism; D044127:Epigenesis, Genetic / Q000187:drug effects; D005472:Fluorouracil / Q000627:therapeutic use*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006023:Glycoproteins / Q000378:metabolism; D045325:HCT116 Cells; D019073:HT29 Cells; D006801:Humans; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D014411:Neoplastic Stem Cells / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D010455:Peptides / Q000378:metabolism; D011379:Prognosis; D011401:Promoter Regions, Genetic / Q000187:drug effects; D016016:Proportional Hazards Models; D034622:RNA Interference; D015398:Signal Transduction / Q000187:drug effects; D018874:Spheroids, Cellular; D013997:Time Factors; D014162:Transfection; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism; D000099273:Neurabins
chemical_list: D000071916:AC133 Antigen; D015703:Antigens, CD; D000964:Antimetabolites, Antineoplastic; D050687:E2F1 Transcription Factor; D005472:Fluorouracil; D006023:Glycoproteins; D008840:Microfilament Proteins; D009419:Nerve Tissue Proteins; D010455:Peptides; D016159:Tumor Suppressor Protein p53; D000099273:Neurabins; C493753:E2F1 protein, human; C000606023:PROM1 protein, human; C495901:TP53 protein, human