The expression and clinical significance of the tRNA aspartic acid methyltransferase 1 protein in gastric cancer.

OBJECTIVES: This study aimed to investigate the role of the tRNA aspartic acid methyltransferase 1 (TRDMT1) protein in the development and progression of gastric cancer (GC). METHODS: The 90 GC tissues and 35 paracancerous tissues (gastric mucosa) were collected from patients (31 males and 59 females; average age 66), who were pathologically diagnosed as GC. The expression of TRDMT1 in three GC cell lines (MKN28, BGC823, and MGC803) and tissues from GC patients were detected by western blotting and immunological staining, respectively. The relationship between TRDMT1 expression and clinicopathological parameters in GC patients was explored. TRDMT1 was knocked down by RNAi lentivirus in GC cells. GC cell migration and invasion were analyzed using scratch and transwell assays. RESULTS: TRDMT1 expression in the GC cell lines was higher than that in the normal gastric mucosal epithelial cell line (P < 0.05). Positive TRDMT1 protein expression in the GC tissue was higher than that in the adjacent tissue. The expression of TRDMT1 was positively associated with tumor size, histological grade, invasion depth, lymph node metastasis, and tumor node metastasis (TNM) stage (P < 0.05). High TRDMT1 expression predicted poor OS of GC patients. Tumor size, differentiation degree, invasion depth, lymph node metastasis, TNM stage, and TRDMT1 expression were independent predictors of the OS of GC patients. Knockdown of TRDMT1 inhibited the migration and invasion of MKN28 cells. CONCLUSION: TRDMT1 was highly expressed in GC cell lines and tissues. TRDMT1 expression was independent predictor of the OS of GC patients. TRDMT1 knockdown reduced GC cell migration and invasion. All these results suggested that TRDMT1 has the potential to be used as a target for the diagnosis and treatment of GC.

miR-20a inhibits the killing effect of natural killer cells to cervical cancer cells by downregulating RUNX1.

BACKGROUND: NK cells are presented in tumor microenvironments and acts as an essential defense line against multiple malignancies. Recently, miRNAs are reported to involve in the development of natural killer (NK) cells via negatively regulating gene expression. Here, we aim to explore the function and mechanism underlying how miR-20a modulated the killing effect of NK cells to cervical cancer cells. METHODS: Abundances of miR-20a and runt-related transcription factor 1 (RUNX1) in NK cells from cervical cancer patients and healthy donors were detected by qRT-PCR and western blot. The releases of IFN-γ and TNF-α were determined by ELISA. The cytotoxicity of NK cells against cervical cancer cells was measured by CytoTox 96 non-radioactive cytotoxicity assay. Luciferase reporter, western blot, and RNA immunoprecipitation (RIP) assays were performed to assess the interaction between miR-20a and RUNX1. RESULT: miR-20a was upregulated while RUNX1 was downregulated in NK cells from cervical cancer patients compared to healthy donors. IL-2 stimulated the releases of IFN-γ and TNF-α, and the killing effect of NK cells to cervical cancer cells, which was overturned by miR-20a introduction. RUNX1 was identified to be a target of miR-20a. Restoration of RUNX1 abolished the inhibitory effects of miR-20a on the secretions of IFN-γ and TNF-α, as well as the killing effect of NK cells to colorectal cancer cells. CONCLUSION: miR-20a attenuated the killing effect of NK cells to cervical cancer cells by directly targeting RUNX1.

Association between EGFR mutation and expression of BRCA1 and RAP80 in non-small cell lung cancer.

Association between the epithelial growth factor receptor (EGFR) mutation and the expression of breast cancer 1 (BRCA1) and receptor-associated protein 80 (RAP80) in non-small cell lung cancer (NSCLC) was studied. From September 2014 to September 2016, 51 patients with NSCLC who were hospitalized in Department of Thoracic Surgery in The Affiliated Jiangyin Hospital of Southeast University Medical College and underwent biopsy or operation were selected. The pathological changes of lung tissue were detected by hematoxylin and eosin histopathological staining. The fluorescent expression of BRCA1 and RAP80 protein in the two groups was determined by immunofluorescence staining. Reverse transcriptase polymerase chain reaction method and western blot analysis were used to detect BRCA1 and RAP80 mRNA and protein expression. Then the EGFR gene mutation was detected and analyzed. The results show that non-small cell lung cancer has an association with smoking. Compared with the control, the lung tissue structure of the NSCLC group was damaged. The protein fluorescence expression of BRCA1 and RAP80 in non-small cell lung cancer group was significantly increased. The expression of BRCA1 and RAP80 mRNA and protein in NSCLC group was significantly increased. The difference in expression of BRCA1 and RAP80 in the control and the non-small cell lung cancer group was statistically significant (P<0.05). EGFR gene mutations detected 14 of the 51 patients with genetic mutations. Non-small cell lung cancer and smoking have certain relevance, and BRCA1 and RAP80 expression in the development and progression of NSCLC has a close relationship. EGFR mutation in non-small cell lung cancer significantly related to the mutation of EGFR and BRCA1 and RAP80 gene expression plays an important role in the diagnosis and treatment of NSCLC.

Genetic variant of miR-146a rs2910164 C>G and gastric cancer susceptibility.

The single nucleotide polymorphism (SNP) rs2910164 G>C within miR-146a has been reported that is associated with the increased risk of gastric cancer (GCa). However, the results are inconclusive, espicially among Asian populations, which probably due to small sample size in each single study. To validate this association and get a more precise estimation, we conducted a large GCa study including 1,125 cases and 1,196 controls in an eastern Chinese population. Our results showed that this SNP was not associated with GCa risk in either of the three genetic models [co-dominant model: CG vs. CC, odds ratio (OR) = 0.99, 95% confidence interval (95%CI): 0.83-1.19; GG vs. CC, OR = 1.03, 95%CI: 0.81-1.32; dominant model: (CG+GG) vs. CC, OR = 1.00, 95%CI = 0.84-1.19; recessive model: GG vs. (CG+CC), OR = 1.04, 95%CI = 0.83-1.29]. Stratified analysis by age, gender, smoking status, drinking status, or tumor location confirmed this non-significant association. In summary, these results suggest that the miR-146a SNP rs2910164 may not be a risk factor for GCa in this Chinese population. Larger and well-designed, preferably prospective studies are needed to further confirm our findings.