Effects and mechanism of adenovirus-mediated phosphatase and tension homologue deleted on chromosome ten gene on collagen deposition in rat liver fibrosis

AIM

To evaluate the effects of phosphatase and tension homologue deleted on chromosome ten (PTEN) gene on collagen metabolism in hepatic fibrosis and the underlying mechanisms.

METHODS

Rat primary hepatic stellate cells (HSCs) and human LX-2 cells were transfected with adenovirus containing cDNA constructs encoding wild-type PTEN (Ad-PTEN), PTEN mutant G129E gene (Ad-G129E), and RNA interference constructs targeting the PTEN sequence PTEN short hairpin RNA to up-regulate and down-regulate the expression of PTEN. HSCs were assayed using fluorescent microscopy, real-time polymerase chain reaction, and western blotting. Moreover, a CCl₄-induced rat hepatic fibrosis model was established to investigate the in vivo effects. Hematoxylin and eosin, and Masson’s trichrome were used to assess the histological changes. The expression of collagen I and III was assessed using immunohistochemistry and western blot analysis.

RESULTS

Elevated expression of PTEN gene reduced serum levels of alanine transaminase and aspartate transaminase, decreased collagen deposition in the liver, and reduced hepatocyte necrosis. In contrast, knockdown of PTEN expression had an opposite effect, such as increased collagen deposition in the liver, and was molecularly characterized by the increased expression of matrix metalloproteinase (MMP)-13 (P < 0.01) and MMP-2 (P < 0.01), as well as decreased expression of the tissue inhibitor of metalloproteinase (TIMP)-1 (P < 0.01) and TIMP-2 (P < 0.01).

CONCLUSION

These data indicated that gene therapy using recombinant adenovirus encoding PTEN might be a novel way of treating hepatic fibrosis.

Discordances in ER, PR and HER2 receptors between primary and recurrent/metastatic lesions and their impact on survival in breast cancer patients

The aim of this study was to evaluate the frequency and prognostic impact of changes in the estrogen (ER), progesterone (PR) and human epidermal growth factor receptor 2 (HER2) status between primary and recurrent/metastatic lesions (RML). We investigated 133 breast cancer patients for ER, PR and HER2 status of primary and RML and their follow-up records. Among 133 patients with RML, discordance rate for ER, PR, and HER2 was 18.8, 33.8, and 6.8%, respectively. ER, PR and HER2 discordance were observed in 20.0, 38.1 and 6.7% of the patients with distant metastasis, and in 14.3, 17.9 and 7.1% of the patients with locoregional recurrence. The mean time between the primary diagnosis and last contact or death was 57 (range 22-78) months and between the recurrence biopsy and last contact or death was 17 (range 1-33) months. Among 133 patients with RML, the ER-discordant cases and ER-loss cases experienced a worse overall survival (OS) (p=0.001 and p=0.016, respectively) and post-recurrence survival (PRS) (p=0.001 and p=0.018, respectively), compared with the respective concordant cases. The HER2-discordant patients and HER2-loss patients had a poorer OS (p=0.008 and p=0.001, respectively) and PRS (p=0.004 and p=0.000, respectively) than the respective concordant cases. Among 105 patients with distant metastasis, ER discordance, ER loss, HER2 discordance and HER2 loss, compared with the respective concordant cases, resulted in a worse OS and PRS (p<0.05 for all). Our findings show an evident change in ER, PR and HER2 between breast primary tumors and relapsing tumors. The unstable status for ER or HER2 in breast cancer seems to be clinically significant and to correlate with a worse prognosis.

Specific shRNA targeting of FAK influenced collagen metabolism in rat hepatic stellate cells

AIM: To investigate the effects and mechanism of disruption of focal adhesion kinase (FAK) expression on collagen metabolism in rat hepatic stellate cells (HSC).

METHODS: The plasmids expressing FAK short hairpin RNA (shRNA) were transfected into HSC-T6 cells, and the level of FAK expression was determined by both real-time quantitative polymerase chain reaction (Q-PCR) and Western blotting analysis. The production of type I collagen and type III collagen in FAK-disrupted cells was analyzed by real-time Q-PCR. The level of collagen metabolism proteins, including matrix metalloproteinases-13 (MMP-13) and tissue inhibitors of metalloproteinases-1 (TIMP-1) was also determined by both real-time Q-PCR and Western blotting analysis.

RESULTS: The transfection of FAK shRNA plasmids into HSC resulted in disrupted FAK expression. Compared with the HK group, the levels of type I collagen and type III collagen mRNA transcripts in FAK shRNA plasmid group were significantly decreased (0.69 ± 0.03 vs 1.96 ± 0.15, P = 0.000; 0.59 ± 0.07 vs 1.62 ± 0.12, P = 0.020). The production of TIMP-1 in this cell type was also significantly reduced at both mRNA and protein levels (0.49 ± 0.02 vs 1.72 ± 0.10, P = 0.005; 0.76 ± 0.08 vs 2.31 ± 0.24, P = 0.000). However, the expression of MMP-13 mRNA could be significantly up-regulated by the transfection of FAK shRNA plasmids into HSC (1.74 ± 0.20 vs 1.09 ± 0.09, P = 0.000).

CONCLUSION: These data support the hypothesis that shRNA-mediated disruption of FAK expression could attenuate extracellular matrix (ECM) synthesis and promote ECM degradation, making FAK a potential target for novel anti-fibrosis therapies.

[Effects of panaxadiol saponins isolated from Panax notoginseng on intracellular and extracellular calcium]

Panaxadiol saponins (PDS) contain saponins Panax notoginseng B1 and E. The spontaneous beating induced by isoproterenol in isolated rat right atria and the increase of contractile force induced by Ca2+ in isolated guinea pig colon were inhibited by PDS 75 and 150 micrograms.ml-1, respectively and perhexiline 6.25 and 12.5 mumol.L-1, respectively. It suggested that PDS could block the potential-dependent and receptor-operated calcium channel in smooth muscle. PDS 150 micrograms.ml-1 and perhexiline 6.25 mumol.L-1 depressed the contractile force induced by norepinephrine and Ca2+ in isolated rat aortic strips in Ca(2+)-free Krebs' solution. It suggested that PDS and perhexiline not only inhibited the release of intracellular Ca2+ but also blocked the inflow of extracellular Ca2+.