Overexpression of the long non-coding RNA, linc-UBC1, is associated with poor prognosis and facilitates cell proliferation, migration, and invasion in colorectal cancer

Figures & data

Figure 1 Expression of linc-UBC1 and OS curves in 96 patients with CRC.

Notes: (A) The expression level of linc-UBC1 in CRC tissues was significantly higher than that in its adjacent noncancerous epithelial tissues (*P<0.001). (B) The OS time of the high linc-UBC1 expression group of CRC patients was significantly shorter than that of the low expression group (P=0.002).
Abbreviations: linc-UBC1, long non-coding RNA upregulated in bladder cancer 1; OS, overall survival; CRC, colorectal carcinoma.

Figure 2 Expression of linc-UBC1 in CRC and normal cells and its role in the regulation of proliferation.

Notes: (A) Expression of linc-UBC1 was markedly higher in the majority of CRC cell lines (SW620, HCT116, and HT29) compared with its expression in NCM460 colonic epithelial cells (*P<0.01). The SW620 cell line exhibited the highest expression level. No difference in expression was identified between SW480 and NCM460 cells. (B) Following treatment with si-linc-UBC1, linc-UBC1 expression in SW620 cell lines was significantly downregulated compared with that in si-NC-treated cells (*P<0.001). (C) The siRNA-mediated silencing of linc-UBC1 significantly inhibited cell proliferation in the SW620 cells (*P<0.05).
Abbreviations: linc-UBC1, long non-coding RNA upregulated in bladder cancer 1; CRC, colorectal carcinoma; siRNA, small interfering RNA; si-linc-UBC1, siRNA targeting linc-UBC1; si-NC, negative control siRNA; OD, optical density.

Table 1 Association between linc-UBC1 expression and clinic o-pathological features in 96 patients with colorectal cancer

Factors	All cases, n (%)	linc-UBC1 expression		χ^2	P-value
		Low, n (%)	High, n (%)
Age at diagnosis (years)
<60	49 (51.0)	25 (51.0)	24 (49.0)	0.042	0.838
≥60	47 (49.0)	23 (48.9)	24 (51.1)
Gender
Male	62 (64.6)	29 (46.8)	33 (53.2)	0.729	0.393
Female	34 (35.4)	19 (55.9)	15 (44.1)
Tumor location
Colon	49 (51.0)	23 (46.9)	26 (53.1)	0.375	0.540
Rectum	47 (49.0)	25 (53.2)	22 (46.8)
Tumor size
<5.0 cm	50 (52.1)	34 (68.0)	16 (32.0)	13.523	0.001
≥5.0 cm	46 (47.9)	14 (30.4)	32 (69.6)
Differentiation status
Poor	35 (36.5)	14 (40.0)	21 (60.0)	2.203	0.138
Moderate or high	61 (63.5)	34 (55.7)	27 (44.3)
Depth of invasion
T1 + T2	18 (18.8)	13 (72.2)	5 (27.8)	4.376	0.036
T3 + T4	78 (81.2)	35 (44.9)	43 (55.1)
Lymph node metastasis
N0	58 (60.4)	35 (60.3)	23 (39.7)	6.672	0.012
N1 + N2	38 (39.6)	13 (34.2)	25 (65.8)
Distant metastasis
M0	85 (88.5)	43 (50.6)	42 (49.4)	0.103	0.749
M1	11 (11.5)	5 (45.5)	6 (54.5)
TNM stage
I + II	55 (57.3)	33 (60.0)	22 (40.0)	5.151	0.023
III + IV	41 (42.7)	15 (36.6)	26 (63.4)

Abbreviation: linc-UBC1, long non-coding RNA upregulated in bladder cancer 1.

Table 2 Multivariate analysis by Cox regression model of factors associated with OS in 96 patients with colorectal cancer

Factors	OS
	Hazard ratio	95% CI	P-value
Age at diagnosis (years) (<60 vs ≥60)	1.093	0.545–2.189	0.803
Gender (male vs female)	1.227	0.581–2.591	0.591
Tumor location (colon vs rectum)	1.446	0.709–2.946	0.310
Tumor size (<5.0 vs ≥5.0 cm)	1.871	0.914–3.831	0.086
Differentiation status (G1 + G2 vs G3)	0.720	0.315–1.646	0.436
Depth of invasion (T1 + T2 vs T3 + T4)	1.463	0.320–6.696	0.624
Lymph node metastasis (N0 vs N1 + N2)	0.539	0.158–1.837	0.323
Distant metastasis (M0 vs M1)	4.016	1.476–10.926	0.006
TNM stage (I + II vs III + IV)	4.977	1.264–19.605	0.022
linc-UBC1 expression (high vs low)	2.434	1.093–5.420	0.029

Abbreviations: OS, overall survival; linc-UBC1, long non-coding RNA upregulated in bladder cancer 1; CI, confidence interval.

Figure 3 Impact of linc-UBC1 on apoptosis and cell cycle distribution of SW620 cells as analyzed by flow cytometry.

Notes: (A) Image of cell apoptosis. (B) Image of cell cycle. (C) Downregulation of linc-UBC1 induced cell cycle arrest at the G2/M phase (*P<0.01). (D) In comparison with si-NC-transfected cells, induction of cell apoptosis was observed in si-linc-UBC1-transfected cells (*P<0.001).
Abbreviations: linc-UBC1, long non-coding RNA upregulated in bladder cancer 1; si-NC, negative control siRNA; si-linc-UBC1, siRNA targeting linc-UBC1; siRNA, small interfering RNA; LR, lower right quadrant; UR, upper right quadrant.

Figure 4 Results of the Western blot analysis of the levels of Bcl-2, cleaved caspase-3, cleaved caspase-9, and GAPDH.

Notes: When transfected with si-linc-UBC1, cleaved caspase-3 and cleaved caspase-9 were significantly increased, whereas Bcl-2 was decreased compared with si-NC-transfected cells (P<0.05).
Abbreviations: si-NC, negative control siRNA; si-linc-UBC1, siRNA targeting linc-UBC1; siRNA, small interfering RNA; GAPDH, glyceraldehyde-3-phosphate dehydrogenase.

Figure 5 Impact of linc-UBC1 on the migration and invasion of SW620 cells (crystal violet staining; original magnification, ×200).

Notes: (A) When transfected with si-linc-UBC1, fewer SW620 cells migrated through the basement membrane compared with si-NC-transfected cells (*P<0.01). (B) When transfected with si-linc-UBC1, fewer SW620 cells invaded through the basement membrane compared with si-NC-transfected cells (*P<0.01).
Abbreviations: linc-UBC1, long non-coding RNA upregulated in bladder cancer 1; si-linc-UBC1, siRNA targeting linc-UBC1; si-NC, negative control siRNA; siRNA, small interfering RNA.