Investigation on the potential adverse outcome pathway of the sensitive endpoint for nephrotoxicity induced by gardenia yellow based on an integrated strategy using bioinformatics analysis and in vitro testing validation.

To explore the potential the adverse outcome pathway of Gardenia Yellow (GY)-induced sensitive endpoint for nephrotoxicity, an integrated strategy was applied in the present study. Using bioinformatic analysis, based on the constructed Protein-protein interaction networks, Gene Ontology function and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis on the core target network were performed to illustrate the potential gene targets and signal pathways. Then, the most enriched pathway was validated with Cell counting kit-8 assays and Western blot analysis in embryonic kidney epithelial 293 cell models. According to the findings, GY may interact with 321 targets related to the endpoint. The five targets on the top ranking in the PPI network were STAT3, SRC, HRAS, AKT1, EP300. Among them, PI3K/Akt was the most enriched pathway. In vitro testing showed that GY exerted a proliferative effect on the cell variability in a dose-dependent manner. GY at concentration of 1000 µg/ml and stimulation for 30 min can significantly enhance the expression of phosphorylated Akt. Thus, after the quantitative weight of evidence evaluation, Akt phosphorylation induced PI3K/Akt activation was speculated as a molecular initiating event leading to a proliferative and inflammatory response in renal tubular epithelial cells.

A repeated dose 28-day oral toxicity study of sodium dehydroacetate (DHA-S) in Wistar rats.

Sodium dehydroacetate (DHA-S) is a food additive and preservative. The present study was conducted to investigate the potential toxicity of repeated oral doses of DHA-S. DHA-S was administered orally by gavage to Wistar rats at doses of 0, 50, 100, or 200 mg/kg BW/day for 28 days, after which growth indicators, clinical pathology, organ weights, and histopathology were determined. Body weight and food consumption were significantly reduced at doses of 100 or 200 mg/kg BW, and some hematological indexes and organ weight were significantly affected, particularly in female rats. At a dose of 200 mg/kg BW, the blood coagulation activities were significantly reduced in female rats. At a dose of 100 or 200 mg/kg BW, the main blood biochemical parameters of both sexes were obviously affected. Similar histological changes in the hepatic and renal tissues were observed in both the treated (200 mg/kg BW DHA-S) and control animals. Female rats were more susceptible to most of the toxic effects caused by DHA-S, which further indicating a gender difference in the toxic phenotype profile of rats. Based on these results, the no observed adverse effect level (NOAEL) of DHA-S was determined to be 50 mg/kg BW/day in rats.

Effects of lanthanum nitrate on behavioral disorder, neuronal damage and gene expression in different developmental stages of Caenorhabditis elegans.

Rare earth elements (REEs) are widely used in the industry, agriculture, biomedicine, aerospace, etc, and have been shown to pose toxic effects on animals, as such, studies focusing on their biomedical properties are gaining wide attention. However, environmental and population health risks of REEs are still not very clear. Also, the REEs damage to the nervous system and related molecular mechanisms needs further research. In this study, the L1 and L4 stages of the model organism Caenorhabditis elegans were used to evaluate the effects and possible neurotoxic mechanism of lanthanum(III) nitrate hexahydrate (La(NO3)3·6H2O). For the L1 and L4 stage worms, the 48-h median lethal concentrations (LC50s) of La(NO3)3·6H2O were 93.163 and 648.0 mg/L respectively. Our results show that La(NO3)3·6H2O induces growth inhibition and defects in behavior such as body length, body width, body bending frequency, head thrashing frequency and pharyngeal pumping frequency at the L1 and L4 stages in C. elegans. The L1 stage is more sensitive to the toxicity of lanthanum than the L4 stage worms. Using transgenic strains (BZ555, EG1285 and NL5901), we found that La(NO3)3·6H2O caused the loss or break of soma and dendrite neurons in L1 and L4 stages; and α-synuclein aggregation in L1 stage, indicating that Lanthanum can cause toxic damage to dopaminergic and GABAergic neurons. Mechanistically, La(NO3)3·6H2O exposure inhibited or activated the neurotransmitter transporters and receptors (glutamate, serotonin and dopamine) in C. elegans, which regulate behavior and movement functions. Furthermore, significant increase in the production of reactive oxygen species (ROS) was found in the L4 stage C. elegans exposed to La(NO3)3·6H2O. Altogether, our data show that exposure to lanthanum can cause neuronal toxic damage and behavioral defects in C. elegans, and provide basic information for understanding the neurotoxic effect mechanism and environmental health risks of rare earth elements.

[Biological implications of the inhibition of survivin by RNA interference in human androgen-independent prostate carcinoma with highly metastatic potential].

OBJECTIVE: To determine the expression level of survivin in androgen-independent prostate carcinoma, and to investigate the biological role of survivin in invasion and metastasis of androgen-independent prostate carcinoma. METHODS: Highly metastatic prostatic cancer cell line PC-3M-1E8 was stably transfected with pSilencer plasmid targeting survivin expression by RNA interference. The biological effects were observed, including anchorage-independent growth, in vitro invasion by soft agar colony formation and Boyden chamber assay, and also in vivo tumorigenesis in nude mice. Cell cycle and apoptosis indices were evaluated by flow cytometry and Western blot analysis of bioactive fragments of caspase 3. RESULTS: The expression of survivin in transfected PC-3M-1E8 cells was markedly depressed at both mRNA and protein levels (about 78% to 80%) as compared with control. The growth of tumor cells was retarded by anchorage-independent growth assay. The survivin transfectants formed smaller and fewer colonies (14.33 +/- 3.51) than the negative (52.33 +/- 6.81) and blank controls (54.00 +/- 6.00). Inhibition of survivin expression was correlated with enhanced apoptosis of tumor cells (percentages of apoptotic cells of the negative control, blank control and experimental groups were 5.88 +/- 0.99, 6.97 +/- 1.60, 16.40 +/- 1.95 respectively), along with an increased expression of activated caspase 3, and cell cycle inhibition at G(0)/G(1) phase (the relative number of cells at G(0)/G(1) phase were 43.65 +/- 3.44, 43.59 +/- 1.83 and 52.71 +/- 1.10, respectively). In addition, multinucleated giant cells were observed along with a marked inhibition of invasion as reflected by fewer penetrating cells by Boyden chamber assay (46.07 +/- 9.97, 47.87 +/- 9.58 and 38.67 +/- 6.59, respectively). CONCLUSIONS: Survivin expression is high in androgen-independent prostate cancer cells and likely may be related to the apoptosis, growth and invasion of the tumor cells. Targeting the survivin pathway by RNA interference appears to be a promising approach for clinical treatment of androgen-independent prostate cancer.

[Monoclonal antibody against G3BP: preparation, characterization and its application in analysis of human tumors].

OBJECTIVE: To better understand the molecular mechanism of tumorigenesis and progression, the monoclonal antibody against G3BP (Ras-GAP SH3 binding protein), which serves as an important downstream effector of Ras signaling, was prepared, characterized and utilized in analysis of various human tumors. METHODS: By using the prokaryotic expression vector pGEX-5X1, GST-G3BP fusion protein was expressed in E. coli BL21 under induction of IPTG. Purified GST-G3BP fusion protein was used to immunize BALB/c mice. The monoclonal antibody against G3BP was produced through conventional hybridoma method and characterized by ELISA, Western blot and immunohistochemical staining. RESULTS: A hybridoma cell line secreting anti-G3BP IgG1 subtype antibody was obtained. Western blot and competitive inhibition assay showed that the antibody was G3BP-specific. Immunohistochemical staining demonstrated that G3BP was over-expressed in formalin-fixed and paraffin-embedded tissues of some human tumors, such as lung cancer, colon cancer, gastric cancer and breast cancer. In breast cancer specimens, the degree of G3BP expression correlated positively with the presence of lymph node metastasis and c-erbB2 expression. CONCLUSIONS: The G3BP-specific monoclonal antibody derived from recombination protein can be used in ELISA, Western blot and immunohistochemical assay. It may provide an important tool in analysis of G3BP in in vitro and in vivo experiments. Besides, G3BP may serve as another prognostic marker for breast cancer.

YMDD variants of HBV DNA polymerase gene: rapid detection and clinicopathological analysis with long-term lamivudine therapy after liver transplantation.

AIM: To look for a rapid low-cost technique for the detection of HBV variants. METHODS: Two patients who underwent orthotopic liver transplantation (OLT) for HBV infection were treated with lamivudine (100 mg daily) and HBV infection recurred in the grafted livers. The patients were monitored intensively for liver enzymes, hepatitis B surface antigen (HBsAg) and HBV DNA in serum. Liver biopsy was performed regularly. HBV DNA in a conserved polymerase domain (the YMDD locus) was amplified from serum of each patient by PCR and sequenced. HBV genotypes were analyzed by restriction fragment length polymorphism (RFLP) of the PCR products generated from a fragment of the polymerase gene. RESULTS: YMDD wild-type HBV was detected in one patient by PCR-RFLP and DNA sequencing 19 mo after OLT, and YIDD mutant-type HBV in the other patient, 16 mo after OLT. CONCLUSION: PCR-RFLP assay is an accurate and simple method for genotyping lamivudine-resistant HBV variants.

[Monoclonal antibodies against human tumor metastasis suppressor gene-1 TMSG-1: preparation, characterization and application].

OBJECTIVE: In order to clarify the exact molecular weight of tumor metastasis suppressor gene-1 (TMSG-1) protein and its cellular localization, a monoclonal antibody against TMSG-1 was prepared, characterized and applied to evaluate the metastatic potential of human tumors. METHODS: A dominant epitope-TMSG-1(15)-derived from TMSG-1 was synthesized based on Fmoc method, and the hapten was conjugated to Imject Maleimide activated mcKLH as a carrier protein. The antigen preparation was used to immunize BAL B/C mice. Hybridomas were generated and screened by ELISA for specific monoclonal antibodies, which were further characterized by western blotting and immunohistochemical staining. RESULTS: One hybridoma cell line secreting anti-TMSG-1 antibody, designated as C8, was eventually established after primary ELISA screening, followed by rapid limited dilution procedure. It was confirmed that C8 was of IgM isotype. Result of competitive inhibition assay showed that the antibody was TMSG-1 specific. Using this antibody, an expected protein band of about 45,000 (relative molecular mass) was detected in the non-metastatic variants PC(3)-2B4 and PG-LH7 cells by Western blotting, but not in the isogenetic metastatic variants of PC3-1E8 and PG-BE1 cells. Immunohistochemistry using C8 showed a positive staining of cell membrane and cytoplasm of 2B4 and LH7 cells, whereas 1E8 and BE1 cells were non-reactive. Immunostaining using C8 of paraffin sections of 52 breast carcinomas and 41 colon cancers demonstrated a strong positivity in non-metastatic tumors, but none to weakly reactive in metastatic tumors (P < 0.05). CONCLUSION: C8 monoclonal antibody against the synthetic peptide is TMSG-1 specific and is effective for Western blot and immunohistochemistry assays to detect TMSG-1 expression in cancer cells. TMSG-1 protein is about 45 000 (relative molecular mass) at cell membrane and cytoplasm of tumor cells. Expression of TMSG-1 protein correlates well, inversely with the tumor metastatic potential.

[Thymosin beta10 expression and actin filament organization in tumor cell lines with different metastatic potential].

OBJECTIVE: To investigate the expression of thymosin beta10 (Tbeta10) and related changes of actin filament organization in human tumor cell lines with different metastatic potential. METHODS: Four groups of nine human tumor cell lines with different metastatic potential were analyzed for the expression of Tbeta10 mRNA detected by northern-blot and its peptide by immunohistochemical staining. The filamentous actin (F-actin) was stained with TRITC-phalloidin to detect changes in actin organization. RESULTS: In comparison with the non and/or weakly metastatic counterparts, Tbeta10 was upregulated in highly metastatic human lung cancer, malignant melanoma and breast cancer cell lines. TRITC-phalloidin staining revealed less actin bundles and a fuzzy network of shorter filaments in the highly metastatic tumor cells, while in the non and/or weakly metastatic cancer cell lines, there were thick and orderly arranged actin filaments. CONCLUSIONS: Tbeta10 levels correlate positively with the metastatic phenotype in human tumors currently examined. The increased metastatic potential of tumor cells is accompanied by the loss of F-actin and poorly organized actin skeleton. There is a consistent correlation between the elevated Tbeta10 expression and the disrupted actin skeleton.

Differential thymosin beta 10 expression levels and actin filament organization in tumor cell lines with different metastatic potential.

BACKGROUND: To investigate the differential expression levels of thymosin beta 10 (T beta 10) and the corresponding changes of actin filament organization in human tumor cell lines with different metastatic potential. METHODS: Four groups of nine human tumor cell lines with different metastatic potential were analyzed for the amount of T beta 10 mRNAs by Northern blot and for their peptide expression levels by immunohistochemistry. The filamentous actin (F-actin) was observed by staining of TRITC-phalloidin to detect changes in actin organization. RESULTS: In comparison with non-/weakly metastatic counterparts, T beta 10 was upregulated in highly metastatic human lung cancer, malignant melanoma and breast cancer cell lines. Staining of TRITC-phalloidin revealed less actin bundles, a fuzzy network of shorter filaments and some F-actin aggregates in the highly metastatic tumor cells. Meanwhile, the actin filaments were robust and orderly arranged in the non-/weakly metastatic cancer cell lines. CONCLUSION: T beta 10 levels correlate positively with the metastatic capacity in human tumors currently examined. The increasing metastatic potential of tumor cells is accompanied by a loss of F-actin, poorly arranged actin skeleton organizations and presence of F-actin aggregates. There is a consistent correlation between the elevated T beta 10 expression and the disrupted actin skeleton.