ABSTRACT
OBJECTIVE Despite the status of cisplatin (DDP) as a classical chemotherapeutic agent in the treatment of cancer, the development of multidrug resistance often leads to a failure of DDP therapy.Traditional Chinese medicine(TCM)as adjuvant chemotherapy of cancer drugs in China has been widely used in cancer treatment.ZuoJin WAN (ZJW),a TCM formula,was proved reversing drug resistance in gastric cancer,but its exact mechanism was still unclear. METHODS CCK-8 assay was used to detect the cell viability. The levels of proteins and mRNA were evaluated using Western blot and q-PCR. Mitochondrial membrane potential was measured by fl ow cytometry. Depolymerisa-tion of F-actin and translocation of G-actin(gamma-actin)from the cytoplasm to the mitochondria was detected using an immuno fl uorescence assay. RESULTS phosphorylated coflin-1 (p-coflin-1) was overexpressed in the DDP-resistant human gastric cancer cell lines SGC7901/DDP and BGC823/DDP, relative to the respective parent cell lines(SGC7901 and BGC823),and DDP induced the dephosphory-lation of p-coflin-1 in both parent lines but not in the DDP-resistant lines. However, ZJW could induce the dephosphorylation of pcoflin-1 and promote coflin-1 translocation from the cytoplasm into the mito-chondria in both SGC7901/DDP and BGC823/DDP cells. This mitochondrial translocation of coflin-1 was found to induce the conversion of flamentous actin to globular-actin, activate mitochondrial dam-age and calcium overloading, and induce the mitochondrial apoptosis pathway. These effects of ZJW on DDP-resistant human gastric cancer cell lines could be reversed via transfection with coflin-1-specifc siRNA,or treatment with a PP1 and PP2A inhibitor.CONCLUSION ZJW can be used as an inhibitor of chemoresistance in gastric cancer, which may partly be due to dephosphorylation of p-coflin-1 via the activation of PP1 and PP2A.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the regulatory effect of jianpi jiedu Recipe (JJR) on the microvessel density (MVD) and cyclooxygenase-2 (COX-2) in long-term infection of Helicobacter pylori induced gastric cancer of C57BL/6 mice, thus providing experimental bases for its treatment of the H. pylori correlated gastropathy.</p><p><b>METHODS</b>C57BL/6 mouse gastric cancer model induced by H. pylori infection was established by gastrogavage of H. pylori standard strain SS1. Mice were divided into the control group, the model group, low dose JJR group, and the high dose JJR group, 40 in each group. Mice were sacrificed after 72-week medication. Changes of the gastric mucosa MVD of mice in each group were detected by immunohistochemical method. Expressions of COX-2 mRNA and protein were detected by Real-time fluorescent quantitative polymerase chain reaction and immunohistochemical method.</p><p><b>RESULTS</b>The occurrence rate of gastric cancer in the control group, the model group, the low dose JJR group, and the high dose JJR group was 0, 22.2%, 11.1%, and 10.0%, respectively. The gastric mucosa MVD (number/cm2) of mice in each group was 2.50 +/- 1.54, 18.56 +/- 2.62, 14.61 +/- 3.60, and 7.39 +/- 1.75, respectively. The gastric mucosa MVD in the model group increased more obviously than that in the control group (P < 0.01). The gastric mucosa MVD significantly decreased in the low dose JJR group and the high dose JJR group (P < 0.01). Expressions of COX-2 mRNA and protein in the model group increased more obviously than those in the control group (P < 0.01). Low dose JJR and high dose JJR could decrease their expressions in a dose dependent manner.</p><p><b>CONCLUSIONS</b>H. pylori infection could increase the gastric mucosa MVD of C57BL/6 mice and promote COX-2 expressions, which might play a promoting effect in the incidence of H. pylori induced gastric cancer. JJR could decrease the gastric mucosa MVD and inhibit COX-2 expressions, which might be one of its important mechanisms of preventing and treating gastric cancer.</p>