The novel long noncoding RNA RP11–357H14.17 acts as an oncogene by promoting cell proliferation and invasion in diffuse-type gastric cancer

Figures & data

Table 1 Correlation between RP11–357H14.17 expression and different clinicopathological features in patients with diffuse-type gastric cancer

Characteristics	High RP11–357H14.17 expression (%)	Low RP11–357H14.17 expression (%)	P-value
Age (years)			0.203
≥60	15 (57.7)	11 (42.3)
<60	6 (37.5)	10 (62.5)
Sex			0.476
Male	13 (58.3)	11 (41.7)
Female	8 (47.1)	10 (52.9)
Tumor size, cm			0.029*
≥5	15 (65.2)	8 (34.8)
<5	6 (31.6)	13 (68.4)
Invasion depth			0.040*
T1,T2	3 (25.0)	9 (75.0)
T3,T4	18 (60.0)	12 (40.0)
TNM stage			0.027*
I/II	5 (29.4)	12 (70.6)
III	16 (64.0)	9 (36.0)
Lymphatic metastasis			0.006*
Positive	19 (63.3)	11 (36.7)
Negative	2 (16.7)	10 (83.3)

Note:

* P<0.05.

Abbreviation: TNM, tumor, node, metastasis.

Figure 1 Hierarchical clustering analysis on the most significantly dysregulated cancer-related lncRNAs.

Notes: 1T, 2T, 3T, 4T, 5T, 6T and 1N, 2N, 3N, 4N, 5N, 6N represented cancerous and paired non-cancerous tissues of samples DGC1, DGC2, DGC3, DGC4, DGC5 and DGC6, respectively.

Figure 2 Relative RP11–357H14.17 expression levels in diffuse-type gastric cancer tissues and cell lines.

Notes: (A) Relative expression of RP11–357H14.17 in 42 pairs of DGC tissues and adjacent normal tissues by qRT-PCR analysis. RP11–357H14.17 levels were calculated by the 2^−Δct method and normalized to glyceraldehyde 3-phosphate dehydrogenase. (B) The fold change of RP11–357H14.17 in DGC relative to the adjacent normal tissues in 42 DGC patients. (C) qRT-PCR detection in 42 pairs of fresh tissues showed RP11–357H14.17 was highly expressed in DGC tissues. (D) Increased RP11–357H14.17 expression in 4 GC cell lines compared with normal gastric epithelial cell line GES-1.
Abbreviations: DGC, diffuse-type gastric cancer; GC, gastric cancer; qRT-PCR, quantitative real-time polymerase chain reaction.

Figure 3 The effects of RP11–357H14.17 on cell viability.

Notes: (A) The relative expression level of RP11–357H14.17 in MGC-803 cell line was significantly decreased by si-RP11–357H14.17, and compared with si-NC. (B) MTT assay showed down-regulation of RP11–357H14.17 inhibited cell proliferation of MGC-803 cell line. (C) Colony-formation assays showed that down-regulation of RP11-357H14.17 signifiantly decreased the colony-forming ability of MGC-803 cell line. (D) Cell cycle analysis determined that down-regulation of RP11–357H14.17 expression promoted G1 phase arrest in MGC-803 cell line. (E) Flow cytometric analysis showed induced cell apoptosis after si-RP11–357H14.17 transfection. The experiments were performed in triplicate. *P<0.05 compared with si-NC, **P<0.01 compared with si-NC.
Abbreviations: CON, MGC-803 cell line; si-NC, si-negative control/non-targeting shRNA; KD, si-RP11–357H14.17.

Figure 4 Knock-down RP11–357H14.17 suppresses migration and invasion of DGC cells. Cell migration and invasion were determined by wound healing assay and transwell assay.

Notes: (A) Inhibition of migration of MGC-803 cell line by RP11–357H14.17 siRNA. (B) Inhibition of invasion of MGC-803 cell line by RP1–357H14.17 siRNA. Data are shown as mean ± standard deviation. The experiments were all repeated at least three times. **P<0.01 compared with NC.
Abbreviations: DGC, diffuse-type gastric carcinoma; CON, MGC-803 cell line; NC, negative control; KD, si-RP11–357H14.17.