General statistical information
In this study, 41 patients with the diagnosis of gastric cancer were enrolled. Out of them 34 patients (82.9%) were male (male to female ratio: 4.8), 7 (17.1%) were smokers, none of the patients were alcoholic drink and the mean age of the patients was 60.32 ± 14.185 years old.
Among the patients, 23 (56.1%) cases were positive for infection by H. pylori. Four (9.8%) patients diagnosed as positive Lymphatic Invasion of the cancer and 34 patients (82.9%) was negative.
The tumor grade of the 3, 16 and 22 patients, was determined as I, II and III respectively and also 4 (9.8%) of them were presented with tumors stage I, 22 (53.7%) with tumors stage III and 15 (36.6%) with stage IV. Out of considered patients, tumor size of 16 (39.0%) cases was ≤ 5 cm and 20 (48.8%) patients had tumor size of >5 cm. Patients in the present study did not receive any preoperative treatment, and those who were undergoing chemotherapy or radiotherapy were eliminated. The more details of demographic characteristics are in Table 2.
Table 2
characteristics of enrolled patients
Characteristics | Sex | Mean age at DX (years) | Risk factors | Tumor size |
M | F | M/F ratio | Smoking | h. pylori infection | Lymphatic invasion | ≤ 5 cm | >5 cm |
Total patients | 34 (82.9%) | 7(17.1%) | 4.8 | 60.32 ± 14.185 | 7 (17.1%) | 23 (60.5%) | 4 (10.5%) | 16 (44.4%) | 20 (55.6%) |
Tumor stage | I | 2 (50%) | 2 (50%) | 1 | 53.25 ±18.78 | - | - | - | - | 1 (100%) |
III | 18 (81.8%) | 4 (18.2%) | 4.5 | 59.77±14.86 | 2 (9.1%) | 15 (68.2%) | 2 (9.1%) | 12 (54.5%) | 10 (45.5%) |
IV | 14 (93.3%) | 1 (6.7%) | 14 | 63±12.06 | 5 (33.3%) | 8 (53.3%) | 2 (13.3%) | 4 (30.8%) | 9 (69.2%) |
Tumor grade | I | 1 (33.3%) | 2 (66.7%) | 0.5 | 44.333±7.23 | - | - | - | - | - |
II | 14 (87.5%) | 2 (12.5%) | 7 | 60.12±14.62 | 3 (18.8%) | 8 (50%) | - | 10 (62.5%) | 6 (37.5%) |
| III | 19 (86.4%) | 3 (13.6%) | 6.3 | 62.63±13.54 | 4 (18.2%) | 15 (68.2%) | 4 (18.2%) | 6 (30%) | 14 (70%) |
M, male; F, Female; M/F, Male to Female |
Expression of lncRNA NEAT1, lincRNA ROR and Oct4 in the tissue samples
To explore the role of lncRNA NEAT1, lincRNA ROR and Oct4 in GC, expression levels quantified in GC tissues. The differences in the expression levels of NEAT1 in the tumor sample between adjacent normal tissues were not statistically significant (p= 0.117) (Fig. 1A). However, gene expression analysis showed significant increased difference between lincRNA ROR samples compared to adjacent normal tissues (Mean = 3.337, p< 0.001) (Figure 1B). Also, there was significant upregulation difference of Oct4 level between the samples of GC patients compared with adjacent normal tissues observed (Mean= 4.385, p<0.001) (Fig. 1C).
Lack of associations between the expression of lncRNAs and clinical characteristics
In order to further evaluate the role of lncRNA NEAT1, lincRNA ROR and Oct4 in gastric cancer, the associations between the RNA levels of the gene and several clinicopathological features including tumor stage, grad, size and H. pylori infection, were also investigated.
there were no significant association between the transcript level of NEAT1 and tumor stages I&III and IV, tumor grades I&II and III, H. pylori infection and tumor size ≤5 & >5 cm (P= 0.911, p= 0.303, p=0.626 and p= 0.076, respectively) (Fig. 2A-D). No significant associations also were determined between the transcript level of lincRNA ROR and clinicopathological variable including stages I&III and IV, grades I&II and III, H. pylori infection and tumor size ≤5 & >5 cm (P= 0.756, p= 0.971, p=0.344 and p= 0.715, respectively) (Fig. 2E-H). In addition, the statistical analysis between Oct4 mRNA expression and clinicopathological features groups revealed no significant association (P= 0.363, p= 0.253, p=0.219 and p= 0.198, respectively) (Fig. 2I-L).
Relative expression of lncRNA NEAT1, lincRNA ROR and Oct4 in individual samples.
In order to determine association between the expression of the lncRNA NEAT1, lincRNA ROR and the Oct4 gene, the relative expression of these genes was compared in each set of the samples. No significant association was observed between the levels of NEAT1comparing occt4 in gastric cancer tissues (R=0.244; P=0.185). In addition, we observed significant association between LincRNA ROR and Oct4 (R=0.417; P=0.024) (Fig. 3).