Journal name: OncoTargets and Therapy Article Designation: Original Research Year: 2017 Volume: 10 OncoTargets and Therapy Dovepress Running head verso: Ni et al Running head recto: Downregulation of lncRNA SDPR-AS is associated with poor prognosis open access to scientific and medical research DOI: http://dx.doi.org/10.2147/OTT.S137641 Open Access Full Text Article ORIGINAL RESEARCH Downregulation of lncRNA SDPR-AS is associated with poor prognosis in renal cell carcinoma Wenjun Ni1,2 Abstract: Renal cell carcinoma (RCC) is a common type of kidney cancer. Normally, surgical Erlin Song1 treatment can prolong life, but only for patients with early stage tumors. However, it is difficult for Mancheng Gong3 early detection strategies to distinguish between benign and malignant kidney tumors. Therefore, Yongxiang Li4 potential biomarkers for early diagnosis and prognosis of RCC are needed. Intriguingly, mounting Jie Yao5 evidence has demonstrated that many long noncoding RNAs (lncRNAs) are strongly linked Ruihua An1 to cancers. Indeed, promising RCC-associated lncRNA biomarkers have also been identified. However, the functional and prognostic roles of the antisense (AS) serum deprivation response 1 Department of Urology Surgery, The (SDPR) lncRNA (SDPR-AS) in RCC remain largely unknown. The aims of this study were First Affiliated Hospital of Harbin Medical University, 2Department to investigate the expression and prognostic relevance of SDPR-AS in RCC. We uncovered For personal use only. of Urology, Heilongjiang Provincial the downregulated expressions of both lncRNA SDPR-AS and its protein-coding gene, SDPR, Hospital, Harbin, Heilongjiang, in RCC tissues compared to the matched normal tissues. Furthermore, SDPR-AS and SDPR 3Department of Urology, The People’s Hospital of Zhongshan, Zhongshan, expressions were positively correlated. Overexpression and knockdown experiments suggested Guangdong, 4Department of Urology, that SDPR-AS and SDPR were coregulated in RCC cell lines. In addition, overexpression of The People’s Hospital of Weifang, Weifang, Shandong, 5Department SDPR-AS suppressed cell migration and invasion, but not cell growth. Furthermore, expression of Oncology, the 161th Hospital of SDPR-AS was associated with tumor differentiation and lymphatic metastasis. Kaplan–Meier of PLA, Wuhan, Hubei, People’s survival and log-rank tests demonstrated the association of elevated expression of SDPR-AS Republic of China with increased overall survival. In conclusion, our results suggest that the SDPR-AS may serve as a prognostic biomarker and therapeutic target of RCC. Keywords: long noncoding RNAs, metastasis, prognosis, renal cell carcinoma, suppressor OncoTargets and Therapy downloaded from https://www.dovepress.com/ by 54.70.40.11 on 12-Nov-2018 Introduction Renal cell carcinoma (RCC) accounts for approximately 2%–4% of all human malignancies and is one of the most common cancers in urology.1,2 Because kidney diseases are mostly asymptomatic during the early stages, many RCC patients are diag- nosed with advanced stage metastatic diseases that are often resistant to chemotherapy, 3 Correspondence: Ruihua An and therefore this is associated with high mortality. Despite the great advances made Department of Urology Surgery, The in the diagnosis and treatment of RCC, therapeutic options are limited and prognosis First Affiliated Hospital of Harbin Medical 4 University, 23 Postal Street, Nangang remains unfavorable. Therefore, there is a need to identify effective biomarkers for District, Harbin, Heilongjiang 150001, predicting the progression and prognosis of RCC and to advance the development of People’s Republic of China Email [email protected] new targeted therapies. During the past decades, numerous studies have revealed that a large portion of Jie Yao the human genome is universally transcribed into noncoding RNAs (ncRNAs).5 Long Department of Oncology, the 161th Hospital of PLA, 68 Huangpu Street, ncRNAs (lncRNAs) are RNA molecules that are larger than 200 nucleotides in length Jiang’an Dsitrict, Wuhan, Hubei 430010, and with no protein coding capabilities.6,7 Recently, many studies have shown that People’s Republic of China Email [email protected] lncRNAs are involved in carcinogenesis, including invasion and metastasis of kidney, submit your manuscript | www.dovepress.com OncoTargets and Therapy 2017:10 3039–3047 3039 Dovepress © 2017 Ni et al. 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Powered by TCPDF (www.tcpdf.org) 1 / 1 Ni et al Dovepress breast, and colorectal cancers.8–10 Particularly in RCC, it has People’s Liberation Army (PLA) General Hospital approved been reported that high expression of lncRNA ATB promotes the utilization of tumor tissues for this study. cell migration and invasion, and correlates with metastases,11 while low expression of lncRNA NBAT-1 increases cell pro- Patients and samples liferation, migration, and invasion, and is also associated with In total, 56 RCC patients who underwent initial surgery at poor prognosis.12 In addition, many other lncRNAs, including the Chinese PLA General Hospital between 2005 and 2007 TUG1,13 BX357664,14 and MEG3,15 have been demonstrated were enrolled into this research. Tumor and adjacent normal to participate in the development and progression of RCC. tissues were immediately snap-frozen in liquid nitrogen after Despite the identification of numerous lncRNAs in RCC, the resection, then maintained at -80°C until use. majority remain unexplored, and this is therefore the reason for conducting this study. Cell culture Through in vitro experiments, Burgener et al16 in 1990 The human RCC cell lines, OS-RC-2, 786-O, 769-P, Caki-1, discovered serum deprivation response (SDPR), also named Caki-2, and ACHN, as well as normal renal cell line HKC cavin-2, located on chromosome 2q32-q33 as a substrate were obtained from American Type Culture Collection for protein kinase C isoforms. SDPR has been confirmed to (ATCC, Manassas, VA, USA). All cells were cultured in be involved in inducing membrane curvature and caveolae Dulbecco’s Modified Eagle’s Medium (Hyclone, UT, USA), formation, and it is strongly linked to gut electrophysiological containing 10% heat-inactivated fetal bovine serum, penicil- 17–19 pacing functions, cell proliferation, and migration. Impor- lin (100 U/mL), and streptomycin (100 μg/mL) in a 5% CO2 tantly, previous studies have indicated that SDPR is down- and humidified atmosphere at 37°C. regulated in kidney, prostate, and breast cancers.20,21 SDPR has also been reported to be a possible biomarker for early SDPR-AS overexpression experiments detection and discrimination of malignant kidney tumors.22 The universally available pcDNA3.1 vector was used for Through bioinformatic analysis, we uncovered an lncRNA, cDNA-SDPR-AS plasmid construction. Following the For personal use only. termed AC098617.1, which is located at chromosome 2q32.3, manufacturer’s instructions, the SDPR-AS low-expressing ranging from 192,711,265 to 192,901,485, with the full OS-RC-2 cells were transfected with pcDNA-SDPR-AS length up to about 190,221 bp (data from UCSC website). using Lipofectamine 2000 (Invitrogen). The transfected cells AC098617.1 (Ensembl Gene ID: ENSG00000233766) were harvested for RNA isolation and functional assays. with 13 transcripts is also known as LOC105373813 Gene or Uncharacterized LOC105373813. Of particular note is SDPR-AS knockdown experiments that the lncRNA is the antisense (AS) transcript of SDPR Small interfering RNAs (siRNAs) for the target SDPR-AS (SDPR-AS) and is located on the upstream of the gene. The (SDPR-AS-si) and negative-control siRNAs (NC-si) were expression and functions of lncRNAs are often associated obtained from GenePharma (Shanghai, People’s Republic with their adjacent protein coding genes.23 It is therefore of China), and the sequences are listed in Table 1. The OncoTargets and Therapy downloaded from https://www.dovepress.com/ by 54.70.40.11 on 12-Nov-2018 tempting to speculate that the expression and functions of SDPR-AS high-expressing 769-P cell line was selected SDPR-AS may also be associated with the progression and for transfection with SDPR-AS-si. Prior to transfection, prognosis of RCC. In this study, we first investigated the 12-well plates were seeded with approximately 50% of expression profiles of SDPR-AS andSDPR in RCC. Subse- the cells and cultured for 24 h. Then, siRNA transfections quently, the functional roles of SDPR-AS in RCC cells were were carried out with X-treme GENE transfection reagents evaluated. Additionally, the correlations between SDPR-AS (Roche) according to the manufacturer’s instructions. RNA expression and clinical variables, as well as prognosis, was isolated after 48 h of transfection and used to perform were examined. functional assays. Materials and methods RNA isolation and reverse transcription Statement of ethics Total RNA was isolated from cells and tissues using