We found that comparing with respective normal kinase inhibitor Oligomycin A cell line, uc001lsz was lowly expressed in gastric cancer (AGS, MGC-803 and SGC-7901), lung cancer (A549) and liver cancer (SMMC-7721 and HepG2) cell lines, while only highly expressed in prostate cancer (Du-145 and PC-3) cell lines (Figure 3C). Potential diagnostic values of H19 and uc001lsz We next performed an analysis to identify whether H19 or uc001lsz expression was associated with the clinicopathological features of gastric cancer. As shown in Table 2, the level of uc001lsz was associated with TNM stages (P=0.032). The positive detection rates of H19 and uc001lsz are 74.0% and 84.4%, respectively. Both of them are higher than those of common gastric cancer biomarker CEA (64.0%) and CA19-9 (53.3%) (Table 2). The areas under ROC curves were up to 0.

613, 0.751, and 0.761 for H19, uc001lsz, and the combination, respectively (Figure 4). The combinative use of H19 and uc001lsz slightly increased the diagnostic value. Table 2 The relationship of H19 and uc001lsz expression levels (��Ct) in cancer tissues with clinicopathological factors of patients with gastric cancera Figure 4 The ROC curve. Expression of uc001lsz was aberrant in early cancer and precancerous lesions At last, to observe the possible early diagnostic values of lncRNA, we measured the level of uc001lsz in early cancer and precancerous lesions. We found that its level was remarkable lower in these lesions compared with those of corresponding adjacent non-tumorous tissues (Figure 5A). The level of uc001lsz in normal tissues was significantly higher than that in precancerous lesions and early cancer tissues.

Besides, its level in precancerous lesions was conspicuous higher than that in early cancer tissues (Figure 5B). Figure 5 Expression of uc001lsz in early cancer and precancerous lesions. The level of uc001lsz in early pathological change tissue is lower than that in paired normal tissue (n=14, P=0.0016; A). The level of uc001lsz in normal … Discussion Studies have shown that ~18% of the protein coding genes that produce lncRNAs are associated with cancer, whereas only 9% of all human protein coding genes are associated with cancer [18]. The relationship between lncRNAs and tumors has currently become one of the focuses of cancer studies. There is mounting evidence that lncRNAs are relation to digestive system tumors [19]. Three lncRNAs, H19, HOTAIR and lncRNA highly upregulated in liver cancer (HULC), were found overexpression in human hepatocellular carcinomas (HCC) [20-22]. In addition, HULC expression is not only confined to HCC, but is also expressed in colorectal carcinomas that metastasize to the liver [23]. Researches about lncRNAs Drug_discovery related to stomach are limited. Sun et al.