Comprehensive genetic study on Chinese carps [Chinese language]

Some text in Englis

ERBB2 increases metastatic potentials specifically in androgen-insensitive prostate cancer cells.

Despite all the blood-based biomarkers used to monitor prostate cancer patients, prostate cancer remains as the second common cause of cancer mortality in men in the United States. This is largely due to a lack of understanding of the molecular pathways that are responsible for the aggressive forms of prostate cancers, the castrate-resistant prostate cancer and the metastatic prostate cancer. Cell signaling pathways activated by the ERBB2 oncogene or the RAS oncogene are frequently found to be altered in metastatic prostate cancers. To evaluate and define the role of the ERBB2/RAS pathway in prostate cancer metastasis, we have evaluated the impact of ERBB2- or RAS-overexpression on the metastatic potentials for four prostate cancer cell lines derived from tumors with different androgen sensitivities. To do so, we transfected the human DU145, LnCaP, and PC3 prostate cancer cells and the murine Myc-CaP prostate cancer cells with the activated form of ERBB2 or H-RAS and assessed their metastatic potentials by three complementary assays, a wound healing assay, a transwell motility assay, and a transwell invasion assay. We showed that while overexpression of ERBB2 increased the metastatic potential of the androgen-insensitive prostate cancer cells (i.e. PC3 and DU145), it did not affect metastatic potentials of the androgen-sensitive prostate cancer cells (i.e. LnCaP and Myc-CaP). In contrast, overexpression of H-RAS only increased the cell motility of Myc-CaP cells, which overexpress the human c-MYC oncogene. Our data suggest that ERBB2 collaborates with androgen signaling to promote prostate cancer metastasis, and that although RAS is one of the critical downstream effectors of ERBB2, it does not phenocopy ERBB2 for its impact on the metastatic potentials of prostate cancer cell lines

EFFECT OF THE C2H2 AND N2 FLOW RATE ON NANOCOMPOSITE nc-ZrCN/a-C:H(N) FILM SYNTHESIZED BY FILTERED CATHODIC VACUUM ARC TECHNIQUE

Nanocomposite nc-ZrCN/a-C:H(N) films were prepared by filtered cathodic vacuum arc technique using the C2H2 and N2 gas as the precursor. The effect of the C2H2 and N2 flow rate on the microstructure, internal stress, phase composition, and mechanical properties of nanocomposite nc-ZrCN/a-C:H(N) films has been investigated by glancing incidence X-ray diffraction (GIXRD), surface profiler, and X-ray photoelectron spectroscopy(XPS). It was revealed that the C2H2 and N2 flow rate affected the structure, Zr content, and internal stress of the films significantly. Furthermore, XRD pattern indicated the presence of the ZrCN crystalline grains in the range of 3–10 nm, and the deconvolution results for XPS spectra showed that the film mainly was constituted by Zr–C, C=C(sp2) and C–C(sp3) bonds.Filtered cathodic vacuum arc technique, nanocomposite nc-ZrCN/a-C:H(N), flow rate

Studies on the expressions and regulations of isozymic genes in silver carp (Hypophthalmichthys molitrix) during ontogenesis

The patterns of expression and regulations in six isozymic systems (LDH, MDH, IDH, ADH, SDH and EST) were investigated in the early developmental stages (from unfertilized eggs to the stage of complete yolk absorption) as well as six differentiated adult tissues (brain, eye, heart, muscle, kidney and liver) of silver carp. Isozymes were resolved by starch or polyacrylamide gel electrophoresis and then detected by specific histochemical staining. Isozymes in adult silver carp apparently exhibit a tissue-specific expression. During the early development period, both ADH and SDH genes seem to be inactive; the other four isozyme genes are active but exhibit different patterns of expressions. It is noteworthy, however that both LDH and EST genes in embryo from two pairs of silver carp parents taken from the same locality exhibit different patterns of expressions and regulations. We argued that these differences are related to the different compositions of LDH and EST isozymes in unfertilized eggs of different female parents. Some related problems which ought to be further studied are also mentioned in the present paper

Biochemical genetic structure and variation in a natural population of silver carp from the middle reaches of the Yangtze River

Using starch and polyacrylamide gel electrophoresis, we analyzed the Oariants of II isozymes encoded by 31 presumptive loci in a natural silver carp population from the middle reaches of the Yangtze River. Among the 27 loci usable for genetic population analysis, four (Ldh-C, Idhp-A, Est-1, -2) were polymorphic. The mean proportion of polymorphic loci and the average heterozygosity per locus in the mentioned population were 14.8% and 0.0451, respectively. Comparative result showed that silver carp hatchery and natural populations had a similar mean proportion of polymorphic loci. It was proposed that the reduction of genetic variability in fish hatchery populations was resulted from some unreasonable factors in propagation process to a great extent and avoiding or minimizing these factors intentionally would be useful for maximizing the genetic variability in hatchery populations of cultural fish species

E2f1, E2f2, and E2f3 Control E2F Target Expression and Cellular Proliferation via a p53-Dependent Negative Feedback Loop

E2F-mediated control of gene expression is believed to have an essential role in the control of cellular proliferation. Using a conditional gene-targeting approach, we show that the targeted disruption of the entire E2F activator subclass composed of E2f1, E2f2, and E2f3 in mouse embryonic fibroblasts leads to the activation of p53 and the induction of p53 target genes, including p21(CIP1). Consequently, cyclin-dependent kinase activity and retinoblastoma (Rb) phosphorylation are dramatically inhibited, leading to Rb/E2F-mediated repression of E2F target gene expression and a severe block in cellular proliferation. Inactivation of p53 in E2f1-, E2f2-, and E2f3-deficient cells, either by spontaneous mutation or by conditional gene ablation, prevented the induction of p21(CIP1) and many other p53 target genes. As a result, cyclin-dependent kinase activity, Rb phosphorylation, and E2F target gene expression were restored to nearly normal levels, rendering cells responsive to normal growth signals. These findings suggest that a critical function of the E2F1, E2F2, and E2F3 activators is in the control of a p53-dependent axis that indirectly regulates E2F-mediated transcriptional repression and cellular proliferation

Overexpression of <i>RAS</i> or <i>ERBB2</i> did not increase lateral cell migration rates.

<p>Cell migration rates were estimated by a wound healing assay for prostate cancer cells that were transfected with either control retroviruses (<i>PBP</i>), or retroviruses overexpressing <i>PBP</i>-<i>H-RAS</i> (<i>RAS</i>) or <i>PBP-ERBB2</i> (<i>ERBB2</i>). Left panels showed percentages of wounds remained at different time points. The percentages of wounds were estimated based on the average of 12 measurements on each plate reflecting measurements of four evenly distributed sections on each of the three wounds/scratches on each plate. Data were presented as means ± SD from three replicates. Right panels showed representative images taken at different time points. All images were taken at the same scale with a scale bar of 200 µM displayed in the first image.</p

Overexpression of <i>RAS</i>/<i>ERBB2</i> activates the MAPK pathway and/or the PI3K–AKT pathway in prostate cancer cells.

<p>Protein levels for various kinases and their phosphorylated forms were assessed by Western blot analyses for parental prostate cancer cells that were transfected either with control retroviruses (<i>PBP</i>), or with retroviruses overexpressing <i>PBP-H-RAS</i> (<i>RAS</i>) or <i>PBP-ERBB2</i> (<i>ERBB2</i>). Actin was used as a loading control. Numbers in white represent protein levels in fold changes relative to those in <i>PBP</i> control cells after the actin normalization.</p

Moderate levels of <i>RAS</i> overexpression did not promote cellular senescence in prostate cancer cells.

<p>(A) Senescence-associated β-galactosidase activities were assessed by X-gal staining for human prostate cancer cell lines transfected with either control retroviruses (<i>PBP</i>) or retroviruses overexpressing <i>PBP-H-RAS</i> (<i>RAS</i>). PC3 cells expressing an extremely high level of <i>RAS</i> (<i>Hi-RAS</i>) were included for comparisons. Senescent BJ human skin fibroblast cells were used as a positive control for X-gal staining. Representative images were shown with representative X-gal-positive cells being marked with red arrows. Inserts in each image showed magnified, representative X-gal-positive cells. (<b>B</b>) Quantifications of data collected from panel (<b>A</b>). Data were presented as means ± SD from three replicates. (<b>C</b>) RAS protein levels assessed by Western blot analysis with antibodies against H-RAS for parental PC3 cells (P), PC3 cells transfected with control retroviruses (<i>PBP</i>), or PC3 cells transfected with the <i>PBP-H-RAS</i> retroviruses overexpressing a moderate level of <i>RAS</i> (<i>RAS</i>) or a much higher level of <i>RAS</i> (<i>Hi-RAS</i>). A blot using antibodies against actin was used as a loading control. Numbers in white represent RAS protein levels in fold changes in <i>ERBB2</i>- or <i>RAS</i>-overexpressing cells relative to those in <i>PBP</i> control cells after the actin normalization. Scare bar: 100 µM.</p