The present study aimed to identify the genes and underlying mechanisms critical to the pathology of spinal cord injury (SCI). Gene expression profiles of spinal cord tissues of trkB.T1 knockout (KO) mice following SCI were accessible from the Gene Expression Omnibus database. Compared with trkB.T1 wild type (WT) mice, the differentially expressed genes (DEGs) in trkB.T1 KO mice following injury at different time points were screened out. The significant DEGs were subjected to function, co‑expression and protein‑protein interaction (PPI) network analyses. A total of 664 DEGs in the sham group and SCI groups at days 1, 3, and 7 following injury were identified. Construction of a Venn diagram revealed the overlap of several DEGs in trkB.T1 KO mice under different conditions. In total, four modules (Magenta, Purple, Brown and Blue) in a co‑expression network were found to be significant. Protein tyrosine phosphatase, receptor type C (PTPRC), coagulation factor II, thrombin (F2), and plasminogen (PLG) were the most significant nodes in the PPI network. 'Fc γ R‑mediated phagocytosis' and 'complement and coagulation cascades' were the significant pathways enriched by genes in the PPI and co‑expression networks. The results of the present study identified PTPRC, F2 and PLG as potential targets for SCI treatment, which may further improve the general understanding of SCI pathology.

The effector function of natural killer, lymphokine--activated killer cells and T lymphocytes is commonly evaluated by radioactive chromium‑release cytotoxicity assays. In addition to this indirect method, fluorescence assays have been described for the assessment of in vitro cell‑mediated cytotoxicity. In the present study, target cells were stained with 5‑(and‑6)‑carboxyfluorescein diacetate succinimidyl ester (CFSE), which is a stable integrated fluorescent probe that allows target and effector cells to be distinguished from one another. Staining of target THP‑1 cells with 8 µM CFSE revealed high and stable loading of fluorescence and no effect of the viability of cells. After 4 h of in vitro co‑culture between γδ T cells and CFSE‑labeled infected or uninfected THP‑1 cells, staining with propidium iodide (PI) was performed to distinguish between vital and dead cells. During sample acquisition, target cells were gated on the CFSE positivity and examined for cell death based on the uptake of PI. CFSE and PI double positive cells were recognized as the dead target cells. The percentage of cytotoxicity in the CFSE‑gated cell population was calculated by subtracting the value obtained for non‑specific PI‑positive target cells, which was measured in a control group that did not contain effector cells. The present study describes a simple and convenient assay that is based on the direct quantitative and qualitative analysis of cell damage at a single cell level utilizing a two‑color flow cytometric assay. In conclusion, the flow cytometric‑based assay described in the current study is a simple, sensitive and reliable tool to determine the cytolytic activity of γδ T lymphocytes against mycobacteria. Therefore, the present study may provide valuable information concerning the methods employed to investigate the function of γδ T cells and potentially other lymphocyte subsets.

Long non‑coding RNA small nucleolar RNA host gene 12 (SNHG12) has been demonstrated to be oncogenic. The aim of the present study was to examine the effects of SNHG12 on the progression of endometrial cancer (EC). The expression levels of SNHG12 and microRNA (miR)‑4429 were assessed in EC cell lines by reverse transcription‑quantitative PCR. Plasmids, including SNHG12 short hairpin RNAs (shRNAs), shRNA negative control (NC), SNHG12 overexpression (OV), OV‑NC, miR‑4429 mimic and mimic‑NC, were transfected into RL95‑2 cells. Post‑transfection, Cell Counting Kit‑8, Transwell Matrigel and wound‑healing assays were performed to assess cell proliferation, invasion and migration, respectively. Cell cycle phase distribution was assessed by flow cytometry. The protein expression levels of matrix metalloproteinase (MMP)2 and MMP9 were detected by western blotting. miR‑4429 target genes were predicted by bioinformatics analysis using target prediction online tools; the findings of this analysis were verified using a dual‑luciferase reporter system. Identified as a target of miR‑4429, SNHG12 was overexpressed in EC cell lines with decreased expression of miR‑4429. Further experiments demonstrated that SNHG12 silencing and overexpression of miR‑4429 markedly suppressed proliferation, migration and invasion of RL95‑2 cells, arrested cells in the G1 phase, and markedly downregulated the expression of MMP2 and MMP9. The opposite effects were observed in miR‑4429 mimic‑transfected RL95‑2 cells after SNHG12 was overexpressed. The findings of the present study established the role of SNHG12 and miR‑4429 in EC. Therefore, targeting the SNHG12/miR‑4429 axis could serve as a potential future therapeutic target for treatment of EC.

Hypermethylation of transcription factor activating enhancer‑binding protein 2e (TFAP2E) has been reported to be associated with chemoresistance to 5‑fluorouracil (5‑FU) in gastric cancer (GC). In the present study, the molecular mechanism governing this chemoresistance was investigated. Drug‑resistant human GC MGC‑803/5‑FU cells were established and TFAP2E expression and methylation levels were assessed. Autocrine exosomes from GC culture medium were isolated and characterized. MicroRNA (miRNA) microarray analysis was used to determine the miRNA expression profile of GC cell‑derived exosomes. Exosomes collected from MGC‑803/5‑FU cells were co‑cultured with control cells, and 5‑Aza‑2'‑deoxycytidine (5Aza) was added into MGC‑803/5‑FU cells to investigate the relationship between TFAP2E, exosomes and chemosensitivity. In the present study, it was demonstrated that hypermethylation of TFAP2E resulted in its reduced expression and 5‑FU chemoresistance in GC cells. miRNAs miR‑106a‑5p and miR‑421 were highly expressed and regulated the chemoresistance induced by TFAP2E methylation. Target gene prediction using miRBase, TargetScan and PicTar revealed that E2F1, MTOR and STAT3 may be TFAP2E target genes in GC. Collectively, our data support an important role of exosomes and exosomal miRNAs in TFAP2E methylation‑induced chemoresistance to 5‑FU in GC. These results highlight their potential for miRNA‑based therapeutics.