Long Noncoding RNAs in Colorectal Adenocarcinoma; an in silico Analysis

Abstract

Long noncoding RNAs (lncRNAs) are lengthy noncoding transcripts which are involved in critical signaling pathways including cell cycle and apoptosis so it is not surprising to see their altered expression in human tumors. Colorectal adenocarcinoma is one the most frequent malignancies worldwide. The role of lncRNAs in colorectal adenocarcinoma is not well understood. To study the significance of lncRNAs in colorectal adenocarcinoma, we retrieved 189 approved lncRNAs from HGNC. The genes were imported into the cBioPortal database for transcriptomic analyses. We queried all the samples from TCGA provisional colorectal adenocarcinoma with RNA-seq v2 data in our study and considered RNA dysregulation with Z-score: ±2. The lncRNA which was altered in most of the patients were considered as "significant lncRNA" for further analyses. We considered the association of candidate lncRNAs with clinicopathologic parameters of samples including tumor disease anatomic site, neoplasm histologic types, tumor stage and survival. We also compute the specificity of the significant lncRNAs expression in colorectal adenocarcinoma comparing with other human cancers in cancer portal. Our analysis showed that lncRNAs SNHG6, PVT1 and ZFAS1 allocated the maximum alteration among the colorectal cases. The expression of SNHG6 and ZFAS1 was more in rectal adenocarcinoma than the colon carcinoma while the PVT1 showed the same expression levels in both tissues. However, we found that upregulation of PVT1 has been reduced the overall survival in patients. Altogether these data showed SNHG6, PVT1 and ZFAS1, are promising candidates for experimental research on colorectal adenocarcinoma to discover novel biomarker for this prevalent cancer.

Long Non-coding RNA Zinc Finger Antisense 1 (ZFAS1) Regulates Proliferation, Migration, Invasion, and Apoptosis by Targeting MiR-7-5p in Colorectal Cancer

“…However, other studies have shown that the expression of ZFAS1 was distinctly upregulated in ovarian cancer and related to survival, and could abolish its target gene SP1 by binding to miR-150 [27]. Current evident has indicated that ZFAS1 might act as a novel target and prognostic factor for the treatment of CRC [31], for instance, Ansari et al revealed that ZFAS1 allocated maximum alteration among the CRC samples and correlated with overall survival in patients [32]; Yan et al showed that ZFAS1 might serve as an oncogene by regulating its downstream target ZEB1 to promote epithelial-to-mesenchymal transition in CRC [33]. In our present study, we revealed that ZFAS1 was increased in CRC tissues compared with adjacent tissues, and had a close correlation with overall survival in CRC patients.…”

PVT1 Long Non-coding RNA in Gastrointestinal Cancer

“…However, the expression of the same PVT1 isoform Sv-203, when determined together with the expression of Sv-206 and Sv-212 (two isoforms that are moderately expressed in colorectal tumors), was not associated with the clinicopathological features described above (69). Additional studies assessing PVT1 overall levels by means of high-throughput technologies such as microarrays or RNA sequencing, observed that high expression values were associated with shorter patient overall survival (67,152). Similarly, in gastric cancer, elevated PVT1 expression was found to be associated with high tumor stage (III-IV) (75)(76)(77)(78), lymph node metastasis (76) and overall/disease-free survival (78).…”

Long noncoding RNA SNHG6 mainly functions as a competing endogenous RNA in human tumors

“…SNHG6 is localized preferentially in the cytoplasm by cytoplasmic and nuclear RNA fractions from some cancer cells, such as hepatocellular cells and colorectal cancer cells [9,10]. According to recent studies, SNHG6 is overexpressed in cancer tissues compared with the corresponding noncancerous tissues as well as in different cancer cell lines [11][12][13]. Upregulated SNHG6 relates to advanced tumor progression and short survival in patients [14,15].…”