Aberrant expression of long noncoding RNA SNHG15 correlates with liver metastasis and poor survival in colorectal cancer.

Long noncoding RNAs (lncRNAs) play a critical role in the initiation and progression of colorectal cancer (CRC), but little is known about the function of lncRNAs in the colorectal liver metastasis (CLM). This study was designed to identify specific lncRNAs correlating to liver metastasis of CRC, and to further assess their clinical value. Seventeen patients with primary CRC lesions, adjacent normal mucosa, and synchronous liver metastases lesions were divided into discovery set (six patients) and test set (11 patients). Transcriptome sequencing (RNAseq) was used to screen differential expression of lncRNAs in the discovery set. Based on bioinformatics data, quantitative reverse-transcription polymerase chain reaction (qRT-PCR) was used to verify the target lncRNA in test set. The relationships between target lncRNA and clinical values were analysed in an expanded validation set of additional 91 patients. 23 upregulated and 14 downregulated lncRNAs were detected for distinguishing synchronous liver metastases, primary CRC lesions from adjacent normal mucosa in the RNAseq set. The expression levels of four lncRNAs in the 37 lncRNA signature were verified by qRT-PCR in the test set. Compared with the paired normal mucosa, high expression levels of lnc-small-nucleolar RNA host gene 15 (SNHG15) were detected not only in primary CRC lesions but also in liver metastases lesions in the test set. Furthermore, in the expanded validation set, high expression of lnc-SNHG15 was significantly associated with lymph-node metastasis and liver metastasis (p < 0.05), and patients displaying high lncRNA-SNHG15 expression exhibited a shorter median overall survival duration than those displaying low expression (30.7 vs. 35.2 months; p = 0.003). Multivariate analyses demonstrated that lncRNA-SNHG15 overexpression may serve as a poor prognostic biomarker for CRC patients (p = 0.049; Cox's regression: 2.731). Lnc-SNHG15 overexpression was significantly associated with CLM and high-expression of lnc-SNHG15 in CRC was an independent predictor of poor survival.

Huang L ，Lin H ，Kang L ，Huang P ，Huang J ，Cai J ，Xian Z ，Zhu P ，Huang M ，Wang L ，Xian CJ ，Wang J ，Dong J ... -  《-》

Aberrant expression of long noncoding RNAs in colorectal cancer with liver metastasis.

Ye LC ，Ren L ，Qiu JJ ，Zhu DX ，Chen T ，Chang WJ ，Lv SX ，Xu J ... -  《-》

A novel long non-coding RNA lnc-GNAT1-1 is low expressed in colorectal cancer and acts as a tumor suppressor through regulating RKIP-NF-κB-Snail circuit.

Ye C ，Shen Z ，Wang B ，Li Y ，Li T ，Yang Y ，Jiang K ，Ye Y ，Wang S ... -  《JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH》

Genome-wide analysis of long noncoding RNA (lncRNA) expression in colorectal cancer tissues from patients with liver metastasis.

The liver is the most frequent site of metastasis in colorectal cancer (CRC), in which long noncoding RNAs (lncRNAs) may play a crucial role. In this study, we performed a genome-wide analysis of lncRNA expression to identify novel targets for the further study of liver metastasis in CRC. Samples obtained from CRC patients were analyzed using Arraystar human 8 × 60K lncRNA/mRNA v3.0 microarrays chips to find differentially expressed lncRNAs and mRNAs. The results were confirmed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The differentially expressed lncRNAs and mRNAs were identified through fold change filtering. Gene ontology (GO) and pathway analyses were performed using standard enrichment computational methods. In the CRC tissues from patients with liver metastasis, 2636 lncRNAs were differentially expressed, including 1600 up-regulated and 1036 down-regulated over two-fold compared with the CRC tissues without metastasis. Among the 1584 differentially expressed mRNAs, 548 were up-regulated and 1036 down-regulated. GO and pathway analysis of the up-regulated and down-regulated mRNAs yielded different results. The up-regulated mRNAs were associated with single-organism process (biological process), membrane part (cellular component), and transporter activity (molecular function), whereas the down-regulated mRNAs were associated with cellular process, membrane, and binding, respectively. In the pathway analysis, 27 gene pathways associated with the up-regulated mRNAs and 51 gene pathways associated with the down-regulated mRNAs were targeted. The significant changes in NQO2 (NM_000904) mRNA and six associated lncRNAs were selected for validation by qRT-PCR. Aberrantly expressed lncRNAs may play an important role in the liver metastasis of CRC. The further study can provide useful insights into the biology and, ultimately, the prevention of liver metastasis.

Chen D ，Sun Q ，Cheng X ，Zhang L ，Song W ，Zhou D ，Lin J ，Wang W ... -  《Cancer Medicine》

LncRNA-SNHG15 enhances cell proliferation in colorectal cancer by inhibiting miR-338-3p.

The incidence and death rate of colorectal cancer (CRC) is very high, which brings great need to understand the early molecular events of CRC. These studies demonstrate that long noncoding RNA (lncRNA) plays an important role in the occurrence and development of human cancer. Small nucleolar RNA host gene 15 (SNHG15) was recently identified as a cancer-related lncRNA. In this study, we aimed to evaluate the function and mechanism of SNHG15 in CRC. The expression of SNHG15 was detected by quantitative RT-PCR (qRT-PCR) in CRC tissues and matched noncancerous tissues (NCTs). CCK-8 assay, colony formation assay, flow cytometric analysis, and nude mouse xenograft mode were used to examine the tumor-promoting function of SNHG15 in vitro and in vivo. The binding relationship between SNHG15, miR-338-3p and the target genes of miR-338-3p were screened and identified by databases, qRT-PCR, dual luciferase reporter assay and western blot. Our results showed that SNHG15 was up-regulated in CRC tissues compared with paired NCTs (P < 0.0001). High level of SNHG15 expression predicted poor prognosis of CRC (P = 0.0051). SNHG15 overexpression could promote cell proliferation and inhibit cell apoptosis. Animal experiments showed that up-regulation of SNHG15 promoted tumor growth in vivo. The results of mechanism experiments showed that SNHG15 could bind to miR-338-3p and block its inhibition on the expression and activity of FOS or RAB14. In conclusion SNHG15 promotes cell proliferation through SNHG15/miR-338-3p/FOS-RAB14 axis in CRC.

Li M ，Bian Z ，Jin G ，Zhang J ，Yao S ，Feng Y ，Wang X ，Yin Y ，Fei B ，You Q ，Huang Z ... -  《Cancer Medicine》