Rs2910164 in microRNA­146a confers an elevated risk of depression in patients with coronary artery disease by modulating the expression of NOS1.

Depression has been well established as an independent predictor of mortality and cardiac morbidity rates in patients with coronary artery disease (CAD). Evidence has shown that single nucleotide polymorphisms located in pre­microRNA (miRNA) or mature miRNA may modify various biological processes and affect the process of carcinogenesis, and the downregulation of neuronal nitric oxide synthase 1 (NOS1) can induce depression. It has been shown that NOS1 is the target gene of miR­146a, and that the rs2910164 G/C polymorphism can downregulate the expression of miR­146a. In the present study, computational analysis was used to identify the target of miR­146a, and a luciferase reporter assay system was used to validate NOS1 as a target gene of miR­146a. In addition, U251 cells were treated with miR­146a mimics/inhibitors to verify the negative regulatory association between miR­146a and NOS1. Reverse transcription­quantitative polymerase chain reaction analysis and western blot analysis were used to estimate the mRNA expression of NOS1 and the expression of miR­146a. The results showed that the 'seed sequence' was located within the 3'­untranslated region of NOS1 by searching an online miRNA database (www.mirdb.org), and the luciferase reporter assay confirmed that NOS1 was a direct target gene of miR­146a. It was also found that the mRNA and protein expression levels of NOS1 in U251 cells treated with miR­146a mimics and NOS1 small interfering RNA were substantially downregulated, compared with cells treated with the scramble control. The cells treated with miR­146a inhibitors showed increased expression of NOS1. In addition, the presence of a minor allele of the rs2910164 polymorphism was significantly associated with risk of depression in patients with CAD. Taken together, the findings indicated a decreased risk of depression in the patients with CAD who were carriers of the miR­146a rs2910164 C allele, and this association may be attributed to its ability to compromise the expression of miR­146a, and thereby increase the expression of its target gene, NOS1.

WWP1 as a potential tumor oncogene regulates PTEN-Akt signaling pathway in human gastric carcinoma.

Whelming evidence has demonstrated that WW domain containing E3 ubiquitin protein ligase 1 (WWP1) participates in a wide variety of biological processes and is tightly related to the initiation and progression of many tumors. Currently, although mounting evidence supports a role of WWP1 in tumor promotion and tumorigenesis, the potential roles of WWP1 and its biological functions in gastric carcinoma are not fully understood. Here, we found that WWP1 messenger RNA (mRNA) and protein were highly expressed in gastric carcinoma tissues and cells. High WWP1 mRNA and protein levels were tightly related to differentiation status, TNM stage, invasive depth, lymph node metastasis, and poor prognosis in gastric carcinoma. Furthermore, WWP1 siRNA significantly decreased WWP1 protein level in MKN-45 and AGS cells; meanwhile, WWP1 depletion markedly inhibited tumor proliferation in vitro and in vivo, arrested cell cycle at G0/G1 phase, and induced cell apoptosis in MKN-45 and AGS cells. Most notably, WWP1 downregulation both inactivated PTEN-Akt signaling pathway in MKN-45 and AGS cells. Taken altogether, our findings suggest that WWP1 acts as an oncogenic factor and should be considered as a novel interfering molecular target for gastric carcinoma.

Identification of a novel HLA-A2-restricted cytotoxic T lymphocyte epitope from cancer-testis antigen PLAC1 in breast cancer.

Identification of cytotoxic T lymphocyte (CTL) epitopes from tumor antigens is essential for the development of peptide vaccines against tumor immunotherapy. Among all the tumor antigens, the caner-testis (CT) antigens are the most widely studied and promising targets. PLAC1 (placenta-specific 1, CT92) was considered as a novel member of caner-testis antigen, which expressed in a wide range of human malignancies, most frequently in breast cancer. In this study, three native peptides and their analogues derived from PLAC1 were predicted by T cell epitope prediction programs including SYFPEITHI, BIMAS and NetCTL 1.2. Binding affinity and stability assays in T2 cells showed that two native peptides, p28 and p31, and their analogues (p28-1Y9 V, p31-1Y2L) had more potent binding activity towards HLA-A*0201 molecule. In ELISPOT assay, the CTLs induced by these four peptides could release IFN-γ. The CTLs induced by these four peptides from the peripheral blood mononuclear cells (PBMCs) of HLA-A*02+ healthy donor could lyse MCF-7 breast cancer cells (HLA-A*0201+, PLAC1+) in vitro. When immunized in HLA-A2.1/Kb transgenic mice, the peptide p28 could induce the most potent peptide-specific CTLs among these peptides. Therefore, our results indicated that the peptide p28 (VLCSIDWFM) could serve as a novel candidate epitope for the development of peptide vaccines against PLAC1-positive breast cancer.

Identification of a novel cytotoxic T lymphocyte epitope from CFP21, a secreted protein of Mycobacterium tuberculosis.

CFP21 is a major secreted protein of Mycobacterium tuberculosis (Mtb) which is considered as a promising antigen for immunotherapy. To identify CFP21-derived HLA-A*0201 restricted epitopes, a series of native peptides and their analogues were predicted with prediction programs and synthesized. The native peptide, p134 (AVADHVAAV), and its analogues, p134-1Y2L and p134-1Y2L9L, showed potent binding affinity and stability to HLA-A*0201 molecule. In ELISPOT assay, the cytotoxic T lymphocytes (CTLs) induced by these peptides could release IFN-γ. In cytotoxicity assay, the CTLs induced by p134 and p134-1Y2L9L could specifically lyse peptide-loaded T2 cells. In these two assays, the native peptide, p134, showed the most potent activity. Our results indicated that p134 could be a novel epitope which could serve as a good candidate to develop peptide vaccines against M. tuberculosis.