Strand-Specific miR-28-5p and miR-28-3p Have Distinct Effects in Colorectal Cancer Cells

• Published in: Gastroenterology (New York, N.Y. 1943) Vol. 142; no. 4; pp. 886 - 896.e9
• Main Authors: Almeida, Maria I, Nicoloso, Milena S, Zeng, Lizhi, Ivan, Cristina, Spizzo, Riccardo, Gafà, Roberta, Xiao, Lianchun, Zhang, Xinna, Vannini, Ivan, Fanini, Francesca, Fabbri, Muller, Lanza, Giovanni, Reis, Rui M, Zweidler–McKay, Patrick A, Calin, George A
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.04.2012
• Subjects: Animals; Apoptosis; Case-Control Studies; Cell Movement; Cell Proliferation; Colorectal Neoplasms - genetics; Colorectal Neoplasms - pathology; Colorectal Neoplasms - therapy; Cyclin D1 - genetics; Cyclin D1 - metabolism; G1 Phase Cell Cycle Checkpoints; Gastroenterology and Hepatology; Gene; Gene Expression Regulation, Neoplastic; Genetic Therapy; HCT116 Cells; Homeodomain Proteins - genetics; Homeodomain Proteins - metabolism; Humans; Mice; Mice, Inbred NOD; Mice, Knockout; Mice, SCID; MicroRNAs - metabolism; Neoplasm Invasiveness; NM23 Nucleoside Diphosphate Kinases - genetics; NM23 Nucleoside Diphosphate Kinases - metabolism; Real-Time Polymerase Chain Reaction; Receptors, Interleukin-2 - deficiency; Receptors, Interleukin-2 - genetics; Reverse Transcriptase Polymerase Chain Reaction; RNA Interference; RNA Processing; Time Factors; Transcript Regulation; Transfection; Tumor Burden; Xenograft Model Antitumor Assays; MSI; colorectal cancer; SCR; PARP1; Transcript Regulation; mRNA; MSS; RNA Processing; precursor miRNA; Gene; messenger RNA; CRC; poly(adenosine diphosphate-ribose) polymerase 1; scrambled negative control; miRNA; microRNA; pre-miRNA; microsatellite stable; microsatellite unstable; PCR; polymerase chain reaction
• ISSN: 0016-5085; 1528-0012
• DOI: 10.1053/j.gastro.2011.12.047

Background & Aims MicroRNAs (miRNAs) can promote or inhibit tumor growth and are therefore being developed as targets for cancer therapies. They are diverse not only in the messenger RNAs (mRNA) they target, but in their production; the same hairpin RNA structure can generate mature products from each strand, termed 5p and 3p , that can bind different mRNAs. We analyzed the expression, functions, and mechanisms of miR-28-5p and miR-28-3p in colorectal cancer (CRC) cells. Methods We measured levels of miR-28-5p and miR-28-3p expression in 108 CRC and 49 normal colorectal samples (47 paired) by reverse transcription, quantitative real-time polymerase chain reaction. The roles of miR-28 in CRC development were studied using cultured HCT116, RKO, and SW480 cells and tumor xenograft analyses in immunodeficient mice; their mRNA targets were also investigated. Results miR-28-5p and miR-28-3p were down-regulated in CRC samples compared with normal colon samples. Overexpression of miRNAs in CRC cells had different effects and the miRNAs interacted with different mRNAs: miR-28-5p altered expression of CCND1 and HOXB3 , whereas miR-28-3p bound NM23-H1 . Overexpression of miR-28-5p reduced CRC cell proliferation, migration, and invasion in vitro, whereas miR-28-3p increased CRC cell migration and invasion in vitro. CRC cells overexpressing miR-28 developed tumors more slowly in mice compared with control cells, but miR-28 promoted tumor metastasis in mice. Conclusion miR-28-5p and miR-28-3p are transcribed from the same RNA hairpin and are down-regulated in CRC cells. Overexpression of each has different effects on CRC cell proliferation and migration. Such information has a direct application for the design of miRNA gene therapy trials.