Reversing multidrug resistance of lung adenocarcinoma xenografts to gemcitabine in combination with cisplatin in mice by Kiwi essence and its mechanism / 肿瘤

Objective: To investigate the effect of Kiwi essence on sensitivity of lung adenocarcinoma xenografts in mice to gemcitabine in combination with cisplatin (DDP) (GP regimen) in mice, and to explore the possible mechanism. Methods: Forty C57BL/6J mice bearing tumor xenografts of Lewis cells were randomized into 5 groups: control group (not tearted with Kiwi essence), high-dose (180 mg/kg) Kiwi essence group, GP group [DDP (3 mg/kg) + gemcitabine (50 mg/kg)], low-dose (60 mg/kg) Kiwi essence combined with GP group, and high-dose (180 mg/kg) Kiwi essence combined with GP group. The growth of tumor xenografts was observed. The mice were sacrificed 20 d after transplantation. The protein and mRNA expression levels of P-glycoprotein (P-gp) and glucose-regulated protein 78 (GRP78) in tumor xenografts were detected by immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR). Results: The tumor growth was inhibited in various degrees in each drug intervention group as compared with that of the control group, and this inhibition effect was most significant in highdose (180mg/kg) Kiwi essence combined with GP group. The mRNA and protein expression levels of P-gp and GRP78 were significantly decreased in low-dose Kiwi essence combined with GP group, high-dose Kiwi essence group, and high-dose Kiwi essence combined with GP group, as compared with those of the control group and GP group (P < 0.01). The expression levels of P-gp and GRP78 proteins and mRNAs were significantly decreased in high-dose Kiwi essence group and high-dose Kiwi essence combined with GP group as compared with that of the low-dose Kiwi essence combined with GP group. Conclusion: Kiwi essence can obviously reverse the multidrug resistance of lung adenocarcinoma to GP chemotherapy in mice. This mechanism may be associated to the down-regulation of P-gp and GRP78.

Seroprevalence of Toxoplasma gondii Infection in Police Dogs in Shenyang, Northeastern China

In recent years, worldwide surveys of Toxoplasma gondii infection in dogs have been reported. However, only limited surveys of T. gondii infection in police dogs have been available, including China. In the present study, we report the seroprevalence of T. gondii in police dogs in Shenyang, northeastern China. Sera from 291 police dogs were examined for T. gondii antibodies with the modified agglutination test (MAT), and 30.9% animals were tested seropositive. The results of the present study indicated a relatively high prevalence of T. gondii infection in police dogs in Shenyang, China.

The regulatory effect of ginsenoside Rg3 on expression of somatostatin receptor in lung carcinoma allografts in mice and its significance / 肿瘤

Objective: To investigate the inhibitory effects of ginsenoside Rg3 on the growth and metastasis of lung carcinoma allografts in mice, and to explore the possible mechanism. Methods: The mice bearing a metastatic variant of Lewis lung carcinoma were established, and then they were randomized to receive 0.9% sodium chloride solution (as a control), DDP (cisplatin), and ginsenoside Rg3 from the fourth day after transplant, respectively. Until the twenty-fourth day after transplant, the mice were sacrificed. The subcutaneous tumor was dissected, and the lung was removed. The inhibitory rate of tumor growth and the number of metastatic foci on the lung surface were counted. The expressions of SSTR (somatostatin receptor), VEGF (vascular endothelial growth factor) and PCNA (proliferation cell nuclear antigen) in subcutaneous tumor were examined by immunohistochemistry. The apoptosis was detected by TUNEL (terminal transferase-mediated dUTP nick end-labeling) method. Results: The inhibitory rates of tumor growth in DDP-treated group and the ginsenoside Rg3-treated group were 39.20% and 54.86%, respectively (P < 0.01). The numbers of metastatic foci on the lung surface in DDP-treated group and the ginsenoside Rg3-treated group were decreased by 30.25% and 58.57%, respectively (P < 0.05). The expression level of SSTR and the apoptosis index in the ginsenoside Rg3- treated group were higher than those in the control group and the DDP-treated group (P < 0.01), while the expression level of VEGF and the proliferation index of PCNA in the ginsenoside Rg3-treated group were decreased as compared with the control group and the DDP-treated group (P < 0.01, P < 0.05). Conclusion: Ginsenoside Rg3 can inhibit the growth and metastasis of lung carcinoma allografts in mice. The mechanism may be associated with the overexpression of SSTR. Copyright © 2012 by TUMOR.

The regulatory effects of quercetin combined with DDP on Bcl-2 and Bax expressions in transplanted lung adeno-carcinoma in mice and their significance / 肿瘤

Objective: To observe the inhibitory effects of quercetin combined with DDP on the growth of transplanted lung adenocarcinoma LA795 cells in T739 mice and detect the expression levels of Bel-2 and Bax and apoptotic index to explore the action mechanism for the combination therapy. Methods: Thirty-two T739 mice inoculated with LA795 lung adenocarcinoma cells were randomly divided into four groups with 8 mice in each group: control group (A), DDP treatment group (B), quercetin treatment group (C), DDP plus quercetin treatment group (D). The tumor growth was observed on day 16 after drug administration. All mice were sacrificed on day 24 after inoculation. The weight and volume of transplanted tumors were recorded. The expression levels of Bcl-2 and Bax were quantified using immunohistochemical method and image analyzing system. The apoptotic index of transplanted tumors was measured by TdT-mediated dUTP-biotin nick end labeling(TUNEL) method. Results: The growth of transplanted tumors in groups B, C, and D were significantly inhibited. The weight of tumor body in the three groups were markedly lower than that of group A. The tumor inhibitory rates were 38.57%, 26.03%, and 51.58% in groups B, C, and D, respectively. The inhibitory effect of quercetin combined with DDP on tumor growth was enhanced compared with quercetin or DDP alone treatment. The expression of Bcl-2 was significantly higher but Bax was significantly lower in group A compared with group B, C, and D. The difference between the drug therapy groups and control group was significant (P< 0.05 or P<0.01). The apoptotic index was significantly increased in the three drug therapy groups compared with control group and the difference was significant (P<0.01). Conclusion: The combination therapy for quercetin plus DDP significantly suppresses the growth of lung adenocarcinoma cells in mice. The action mechanism may be due to regulation of Bcl-2 and Bax expressions, thereby, inhibiting cell proliferation and inducing apoptosis.