Effect of Huaier on the proliferation and apoptosis of human gastric cancer cells through modulation of the PI3K/AKT signaling pathway.

The aim of the present study was to investigate the effect of Huaier on the proliferation and apoptosis of the MKN45 and SGC7901 gastric cancer cell lines. The MTT assay was used to measure the effects of Huaier on the growth of the cells, while cell cycle distribution and apoptosis levels were analyzed using flow cytometry. Western blotting was used to assess the levels of proteins associated with the apoptotic pathway. It was found that cell survival decreased with the increase in the concentration of Huaier, and the apoptosis rates were increased in a dose-dependent manner both in MKN45 and SGC7901 cells. The number of cells in the G2/M phase in the Huaier-treated groups was increased in a dose-dependent manner compared with that in the control group. Huaier inhibited phosphorylated- (p-)AKT1, phosphatidylinositol 3-kinase (PI3K), pyruvate dehydrogenase kinase isoform 1, p-phosphatidylinositol 3,4,5-trisphosphate 3-phosphatase and dual-specificity protein phosphatase and B-cell lymphoma 2 expression and upregulated cleaved-caspase-9 expression in a dose-dependent manner. In conclusion, Huaier can strongly inhibit gastric cancer cell proliferation by inhibiting cyclin B1 expression, promoting G2/M-phase arrest and modulating the PI3K/AKT signaling pathway, and can induce gastric cancer cell apoptosis by modulating the PI3K/AKT signaling pathway in dose-dependent manner.

5-Fluorouracil chemotherapy of gastric cancer generates residual cells with properties of cancer stem cells.

BACKGROUND: 5-Fluorouracil (5Fu) chemotherapy is the first treatment of choice for advanced gastric cancer (GC), but its effectiveness is limited by drug resistance. Emerging evidence suggests that the existence of cancer stem cells (CSCs) contributes to chemoresistance. The aim of the present study was to determine whether 5Fu chemotherapy generates residual cells with CSC-like properties in GC. METHODS: Human GC cell lines, SGC7901 and AGS, were exposed to increasing 5Fu concentrations. The residual cells were assessed for both chemosensitivity and CSC-like properties. B lymphoma Mo-MLV insertion region 1 (BMI1), a putative CSC protein, was analyzed by immunohistochemical staining and subjected to pairwise comparison in GC tissues treated with or without neoadjuvant 5Fu-based chemotherapy. The correlation between BMI1 expression and recurrence-free survival in GC patients who received 5Fu-based neoadjuvant chemotherapy was then examined. RESULTS: The residual cells exhibited 5Fu chemoresistance. These 5Fu-resistant cells displayed some CSC features, such as a high percentage of quiescent cells, increased self-renewal ability and tumorigenicity. The 5Fu-resistant cells were also enriched with cells expressing cluster of differentiation (CD)133+, CD326+ and CD44+CD24-. Moreover, the BMI1 gene was overexpressed in 5Fu-resistant cells, and BMI1 knockdown effectively reversed chemoresistance. The BMI1 protein was highly expressed consistently in the remaining GC tissues after 5Fu-based neoadjuvant chemotherapy, and BMI1 levels were correlated positively with recurrence-free survival in GC patients who received 5Fu-based neoadjuvant chemotherapy. CONCLUSIONS: Our data provided molecular evidence illustrating that 5Fu chemotherapy in GC resulted in acquisition of CSC-like properties. Moreover, enhanced BMI1 expression contributed to 5Fu resistance and may serve as a potential therapeutic target to reverse chemoresistance in GC patients.

[Distribution and property of anti-beta3-adrenoceptor autoantibody in patients with heart failure].

OBJECTIVE: To investigate the biological effects of anti-beta(3) adrenoceptor (beta(3)-AR) autoantibody in the serum of patients with heart failure, which may contribute to a new therapeutic clue for heart failure. METHODS: The synthetic peptide of the second extracellular loop of the beta(3)-AR was used as the antigen to screen sera of patients with heart failure and of healthy controls by using enzyme-linked immunosorbent assay. IgG in the patients group of positive autoantibody sera was prepared by using a MabTrap Kit (Amersham) following the manufacturer's instructions. The effects of IgG per each group both on contractile response of adult isolated cardiomyocytes and on beating frequency of cultured neonatal rat cardiomyocytes were observed. RESULTS: The positive rate of anti-beta(3)-AR autoantibody was 26.7% (mean antibody titer: 1:43.27 +/- 2.71) or 11.0% (mean antibody titer: 1:14.59 +/- 1.61) in patients or healthy subjects, respectively P < 0.05. Compared with the control group, the autoantibody against beta(3)-AR from the patients group decreased cell shortening amplitude/cell shortening 3.84% +/- 0.33%, the velocity of shortening -0.47 microm/s +/- 0.07 microm/s and relengthening 0.17 microm/s +/- 0.02 microm/s in adult isolated cardiac myocytes, respectively. The autoantibody in the patients group decreased the beating rate in cultured neonatal rat cardiac myocytes by 47.1 beats/min +/- 8.11 beats/min, which could have a 6-hour continuance. This decreasing was not modified by Nadolol (beta(1)-AR and beta(2)-AR antagonist) in pretreating myocytes, but was nearly prevented by Bupranolol (nonselective beta-AR antagonist) or beta(3)-AR specific antigen. CONCLUSION: It seems reasonable to state that a high titer of the autoantibody against beta(3)-AR in the serum in patients with heart failure, which could have a negative inotropic and chronotropic effect, may be a part of pathophysiological mechanisms of heart failure.