Effect of long non-coding RNA Gas5 on proliferation, migration, invasion and apoptosis of colorectal cancer HT-29 cell line.

Objective: This study aims to investigate the effect of long non-coding RNA (lncRNA) Gas5 on proliferation, migration, invasion and apoptosis of colorectal cancer (CRC) HT-29 cell line. Methods: CRC and normal tissues were collected and prepared from a total of 126 CRC patients, and normal intestinal epithelial cell line FHC and CRC cell lines (HCT-8, HT-29, HCT-116 and SW-480) were prepared. Gas5 expression was detected by quantitative reverse transcriptase-polymerase chain reaction. HT-29 cell line exhibiting the lowest Gas5 expression was selected for further experimentation and divided into blank, negative control and pcNDA-Gas5 groups. The cell counting kit-8 assay was used to test cell proliferation. Flow cytometry was applied to examine cell apoptosis. Transwell assay was performed to detect the migration and invasion of HT-29 cells. The mRNA and protein expression of factors in the classical proliferation (Akt/Erk) and apoptosis (caspase-9/caspase-3) pathways were detected. Results: Gas5 expression was lower in CRC tissues compared to the adjacent normal tissues, and is also lower in CRC cell lines than FHC cell line. Gas5 expression was associated with tumor size and TNM staging. Gas5 expression, distant metastasis, tumor differentiation and TNM staging were independent CRC prognostic factors. The results showed that elevated Gas5 expression inhibited proliferation, migration and invasion, but promoted apoptosis of CRC cells. Meanwhile, elevated Gas5 expression inhibited mRNA expression of Akt and Erk and protein expression of p-Akt and p-Erk, which promoted Casp9 mRNA and pho-Casp9 protein expression but inhibited Casp3 mRNA and pho-Casp3 protein expression. Conclusion: The findings indicated that overexpression of lncRNA Gas5 can inhibit the proliferation, migration and invasion but promote apoptosis of CRC cells.

In vivo and in vitro effects of microRNA-124 on human gastric cancer by targeting JAG1 through the Notch signaling pathway.

In this study, we aim to determine the function of miR-124 on gastric cancer (GC) cells and the underlying mechanism that involves jaddeg1 (JAG1) and the Notch signaling pathway. GC tissues and adjacent tissues from 100 patients suffering from GC were selected. GC SGC-7901 and AGS cells were selected and grouped into control, mimic-NC, miR-124 mimic, inhibitor-NC, miR-124 inhibitor, and miR-124 inhibitor + si-JAG1 groups. RT-qPCR and a Western blotting assay were conducted to detect the expression of miR-124, JAG1, and Notch signaling pathway-related proteins (NICD, HES1, and HES5). MTS, wound-healing, transwell assay and flow cytometry were performed to detect cell proliferation, migration, invasion, cell cycle distribution, and apoptosis, respectively. Compared with adjacent tissues, a lower miR-124 expression and higher JAG1 expression were found in GC tissues. JAG1 is a direct target gene of miR-124. Compared with the control group, the expression of JAG1, NICD, HES1, and HES5, cell invasion, migration, and proliferation in the miR-124 mimic group were decreased, while the apoptosis rate was increased and cells were arrested at the G0/G1 phase. Compared with the miR-124 inhibitor group, the expression of JAG1, NICD, HES1, and HES5, cell invasion, migration, and proliferation in the miR-124 inhibitor + si-JAG1 group were decreased, while the apoptosis rate and cell ratio at the G0/G1 phase were increased. The demonstration that miR-124 inhibits GC cell growth supports the concept that miR-124 functions as a tumor suppressor by a mechanism that involves translational repression of the JAG1 and the inhibition of Notch signaling pathway.

Possible prognostic significance of p53, cyclin D1 and Ki-67 in the second primary malignancy of patients with double primary malignancies.

Patients with two types of primary cancers are rare. In this study, we investigated the expression of p53, cyclin D1, and Ki-67 in the second primary malignancy. Tissue samples were obtained from the second primary cancer site of 43 patients who met the diagnostic criteria for double primary cancer. p53, cyclin D1 and Ki-67 were determined using immunohistochemistry. Categorical variables were compared using the Chi-squared test; correlation between data scores and histology was calculated using the Spearman's rank-order correlation. The expression rates of p53, cyclin D1 and Ki-67 in the second primary malignancy site were 60.5%, 30.2% and 65.1% respectively. p53 expression showed statistically significant association with tumor occurrence interval, pathological grading and nodal metastasis (p < 0.05). Positive correlation was detected between the expression of cyclin D1 and Ki-67 and the expression of p53 (r = 0.313, p = 0.041; r = 0.319, p = 0.037, respectively). High-expressing p53 or cyclin D second primary malignancies were associated with decreased overall survival (p = 0.040 and p = 0.043, respectively). Ki-67 expression levels did not exhibit statistically significant differences in survival. In conclusion, elevated protein expression of p53, cyclin D1 and Ki-67 in the second primary malignancy is an indicator of more aggressive malignant behavior of the secondary tumor. These markers may have prognostic value in the clinical setting.