The identification of miR-375 as a potential biomarker in distal gastric adenocarcinoma.

MicroRNAs (miRNAs) are endogenous small noncoding RNAs that negatively regulate gene expression at the posttranscriptional level and play an important role in carcinogenesis. Herein, we characterized the global expression of miRNA in distal gastric adenocarcinomas and determined if circulating miRNAs could be used as biomarkers for distal gastric adenocarcinoma. We used a microarray screening system to detect dysregulated miRNAs in distal gastric adenocarcinoma tissues. The expression of a subset of five aberrantly expressed miRNAs (miR-375, -196b, -204, -18b, and -93) were further quantified in an independent set of clinical samples of distal gastric adenocarcinoma by real-time quantitative RT-PCR (rt-qRT-PCR). We also used rt-qRT-PCR to investigate the expression levels of putative miRNA biomarkers in serum and tumor cell lines. In our study, the expression of a subset of microRNAs was altered in distal gastric adenocarcinoma compared to normal tissue, miR-375 was significantly downregulated in distal gastric adenocarcinoma tissues, to a level that was significantly lower than cardia adenocarcinoma (p < 0.05). The circulating serum levels of miR-375 in patients who had distal gastric adenocarcinoma were also much lower than normal controls (p < 0.001). As a biomarker, miR-375 yielded a receiver operating characteristic area under the curve of 0.835. The specificity and sensitivity was 80% and 85%, respectively, in the discrimination of distal gastric adenocarcinoma from control, at a normalized cutoff of 0.218. The expression of miR-375 was downregulated both in distal gastric adenocarcinoma tissues and serum of patients with distal gastric adenocarcinoma. These data suggest miR-375 is a potential biomarker for distal gastric adenocarcinoma.

[Comparison of sperm parameters between male adults at different altitudes].

OBJECTIVE: To investigate the influence of long-term anoxic exposure on the sperm function of male adults at different altitudes. METHODS: A total of 28 male adults that had stayed at the altitude of 5 340 m for 1-3 years were included as a high-altitude group (HAG), 34 at the mean altitude of 3 800 m for 2-5 years as a middle-altitude group (MAG) and 31 permanently at the altitude of 1 300 m as controls. Semen specimens were collected and the real-time semen analysis was performed by using computer-assisted semen analysis (CASA) system. RESULTS: The sperm density, VCL, VSL, VAP and LIN in the HAG were (51.12 +/- 14.61) x 10(6)/ ml, (48.17 +/- 13. 52) microm/s, (32.64 +/- 6.70) microm/s, (41.21 +/- 9.32) microm/s and 52.24 +/- 8.14, respectively, significantly lower than those of the control (P < 0.01 or P < 0.05). Compared with the control group, there was a progressive decrease in sperm concentration, sperm motility rate, VSL, VCL, LIN, VAP and ALH in the MAG. CONCLUSION: The higher the altitude, the more obvious was the negative effect of anoxic exposure on the sperm function of male adults.

[Pro-apoptotic efficiencies of three reconstructed human caspase-8 on cervical cancer cell line HeLa].

BACKGROUND & OBJECTIVE: Apoptosis is a kind of evolutional high conservative cell death. Transferring high active pro-apoptotic molecules into cancer cells to induce apoptosis is a potential strategy for cancer gene therapy. Based on our previous generation of reconstructed human caspase-8, which can continuously induce apoptosis of cervical cancer cell line HeLa, by reversing its large and small subunits, this study was designed to investigate the pro-apoptotic efficiencies of 3 reconstructed human caspase-8 (Casp8CD, Rev8, and Rev8L) on HeLa cells, and to explore the feasibility of reconstructed human caspase-8 as potential apoptosis-inducing candidates. METHODS: The eukaryotic expression vectors pIRES2-EGFP carrying Casp8CD, Rev8, and Rev8L genes were transfected into HeLa cells, and breast cancer MCF-7 cells. Expressions and pro-apoptotic effects of Casp8CD, Rev8, and Rev8L genes were observed under fluorescent microscope, and their pro-apoptotic efficiencies were assessed by MTT assay and cells counting. The flexibilities of linking-peptides between subunits of Rev8 and Rev8L were analyzed by bioinformatics. RESULTS: Expressions of the 3 reconstructed caspase-8 genes were observed under fluorescent microscope, and the HeLa and MCF-7 cells expressing Rev8 or Rev8L genes displayed typical apoptotic volume decrease (AVD). MTT assay showed that compared with control cells, A(570) values of Rev8- and Rev8L-transfected cells began to decrease 20 h after transfection. Cell counting results indicated that cell death ratio of Casp8CD-, Rev8-, and Rev8L-transfected cells were 16.9%, 52.3%, and 47.7%, respectively, 24 h after transfection; and 12.9%, 51.6%,and 61.2%,respectively,48 h after transfection. Bioinformatics analysis showed that the linking-peptides between subunits of Rev8 and Rev8L were flexible. CONCLUSION: Rev8 and Rev8L molecules have similar pro-apoptotic effects and efficiencies, but over-expressed Casp8CD had no significant pro-apoptotic effects.

[The chromosomal location of AD7C-NTP gene and the prediction of transmembrane domains of its deduced protein].

AIM: To characterize the chromosomal location of AD7C-NTP gene and predict the transmembrane domains and sub-cellular location of its deduced protein. METHODS: The AD7C-NTP mRNA sequence was alignmented with human genomic DNA sequence by Blat server. The transmembrane domains and sub-cellular location of AD7C-NTP protein were predicted by using PHDhtm, TMHMM2.0, HMMTOP2.0, SMART and PSORT servers, etc. RESULTS: The AD7C-NTP gene located in minus strand of 1p36.11, without intron. The AD7C-NTP protein was predicted to have 3 potential transmembrane domains and locate on peroxisome's membrane. CONCLUSION: Bioinformatics analysis of the AD7C-NTP gene and its deduced protein provides valuable clues for further gene cloning and study of function.

[Construction, expression and cell growth inhibition of translocating peptide/granzyme B fusion protein gene].

AIM: To investigate the inhibitory effect of translocating peptide/granzyme B fusion protein on cell growth. METHODS: The translocating peptide gene of Pseudomonas exotoxin A (PE) was fused with active granzyme B gene by recombinant PCR to construct PE II-GrBa fusion protein gene. PE II-mGrBa with a mutation of serine to cystein at active center of GrB was used as negative control. The resulting PE II-GrBa and PE II-mGrBa genes were transiently transfected into mammalian cells via lipofectamine mediation. The effects of expression of PE II-GrBa gene on morphology and growth of transfected cells were detected by MTT colorimetry, TUNEL assay and indirect immunofluorescence staining. RESULTS: Transient expression of PE II-GrBa resulted in cytoskeleton abnormality, cell growth inhibition, and apoptosis in some cells. CONCLUSION: Expression of PE II-GrBa fusion protein can inhibit cell growth.

Specific tumoricidal activity of a secreted proapoptotic protein consisting of HER2 antibody and constitutively active caspase-3.

In this study, a novel approach to antitumor therapy was devised by generating a chimeric tumor-targeted killer protein, referred to as immunocasp-3, that comprises a single-chain anti-erbB2/HER2 antibody with a NH(2)-terminal signal sequence, a Pseudomonas exotoxin A translocation domain, and a constitutively active caspase-3 molecule. In principle, cells transfected with the immunocasp-3 gene would express and secrete the chimeric protein, which then binds to HER2-overexpressing tumor cells. Subsequent cleavage of the constitutively active capase-3 domain from the immunocasp-3 molecule and its release from internalized vesicles would lead to apoptotic tumor cell death. To test this strategy, we transduced human lymphoma Jurkat cells with a chimeric immunocasp-3 gene expression vector and showed that they not only expressed and secreted the fusion protein but also selectively killed tumor cells overexpressing HER2 in vitro. i.v. injection of the transduced Jurkat cells led to tumor regression in a mouse xenograft model because of continuous secretion of immunocasp-3 by the transduced cells. The growth of HER2-positive tumor cells in this model was inhibited by i.m. as well as intratumor injection of immunocasp-3 expression plasmid DNA, indicating that the immunocasp-3 molecules secreted by transfected cells have systematic antitumor activity. We conclude that the immunocasp-3 molecule, combining the properties of a tumor-specific antibody with the proapoptotic activity of a caspase, has potent and selective antitumor activity, either as cell-based therapy or as a DNA vaccine. These findings provide a compelling rationale for therapeutic protocols designed for erbB2/HER2-positive tumors.