Latexin inhibits the proliferation of CD133+ miapaca-2 pancreatic cancer stem-like cells.

BACKGROUND: An increasing number of evidence suggests that pancreatic cancer contains cancer stem cells (CSCs), which may be relevant to the resistance of chemotherapy. Latexin (Lxn) is a negative regulator of stem cell proliferation and we investigate the effects of Lxn on CD133+ pancreatic cancer stem-like cells. METHODS: CD133+ miapaca-2 cells, a human pancreatic carcinoma cell line, were isolated and sorted by magnetic activated cell sorting and flow cytometry. The capacity for self-renewal, proliferation, and tumorigenicity of CD133+ miapaca-2 cells was determined by the floating spheres test and tumor xenograft assays. Protein and mRNA expression of Lxn in CD133+ and CD133- miapaca-2 cells were detected by Western blotting and qRT-PCR, respectively. After CD133+ miapaca-2 cells were treated with Lxn in serum-free medium (SFM), cell proliferation was assayed with a Cell Counting Kit 8 (CCK-8) and apoptosis was analyzed by flow cytometry. The protein and mRNA expression levels of Bcl-2, bax, and c-myc were also analyzed. RESULTS: We successfully isolated CD133+ miapaca-2 cells that exhibited the capacity for self-renewal in SFM, a proliferation potential in DMEM supplemented with FBS, and high tumorigenicity in nude mice. Lxn protein and mRNA expression levels in CD133+ miapaca-2 cells were significantly lower than those in CD133- cells. Lxn-treated CD133+ miapaca-2 cells exhibited increased apoptosis and low proliferation activity, down-regulation of Bcl-2 and c-myc expression, and up-regulation of Bax expression in a dose-dependent manner. CONCLUSIONS: Lxn induces apoptosis and inhibits the proliferation of CD133+ miapaca-2 cells. These changes are associated with down-regulation of Bcl-2 and c-myc and up-regulation of Bax.

Artesunate inhibits the growth of gastric cancer cells through the mechanism of promoting oncosis both in vitro and in vivo.

This study aims to investigate the significance and mechanism of artesunate involved in suppressing the proliferation of gastric cancer in vitro and in vivo. In the in-vitro experiments, artesunate inhibited the growth of gastric cancer cell lines (SGC-7901, BGC-823, and AGS) with concentration-dependent activity, with no significant effect on GES-1 cells. BGC-823 cells treated with artesunate showed the typical morphologic features of oncosis rather than apoptosis. Meanwhile, we observed calcium overload, downregulation of vascular endothelial growth factor expression, and upregulation of calpain-2 expression in the artesunate-treated BGC-823 cells. In addition, the in-vivo study showed that artesunate produced a dose-dependent tumor regression in nude mice. The antitumor activity of 240 mg/kg artesunate was similar to that of 10 mg/kg docetaxel. Furthermore, compared with the control group, no significant difference was observed in the body weight of artesunate-treated nude mice other than docetaxel-treated nude mice. These observations show that artesunate has concentration-dependent inhibitory activities against gastric cancer in vitro and in vivo by promoting cell oncosis through an impact of calcium, vascular endothelial growth factor, and calpain-2 expression.

Gossypol induces cell death by activating apoptosis and autophagy in HT-29 cells.

Gossypol is a polyphenolic, yellowish compound derived from cottonseed extract. The present study examined the effects of gossypol on the apoptosis and autophagy of HT­29 cells. A Cell Counting Kit­8 assay, Annexin V­FITC, JC­1 staining and western blotting were used to identify the viability of cells, stages of apoptosis and the expression levels of the signaling proteins. Gossypol promoted apoptosis and induced the loss of mitochondrial membrane potential. Further investigation of the apoptotic mechanism revealed that gossypol increased the ratio of B­cell lymphoma 2 (Bcl-2)-associated X protein/Bcl­2 protein levels and upregulated the expression of caspase­3. Gossypol also enhanced the activity of microtubule­associated protein light chain 3 LC3­II and Beclin­1 and downregulated LC3­I, in a dose­dependent manner. Together, these finding suggested that gossypol may be a novel and potential antitumor agent.

Romidepsin induces G2/M phase arrest via Erk/cdc25C/cdc2/cyclinB pathway and apoptosis induction through JNK/c-Jun/caspase3 pathway in hepatocellular carcinoma cells.

The aim of the study is to demonstrate the effect of Romidepsin in hepatocellular carcinoma (HCC) by inducing G2/M phase arrest via Erk/cdc25C/cdc2/cyclinB pathway and apoptosis through JNK/c-Jun/caspase3 pathway in vitro and in vivo. Human HCC cell lines were cultured with Romidepsin and DMSO (negative control) and 5-fluorouracil (positive control). Then the cells' viability and apoptosis were determined by cell proliferation assay and flow cytometry. Protein concentrations and expression changes were measured by Western blot. Subsequently, Huh7 cells were subcutaneously inoculated into the nude mice, which were employed to further probe the tumor-suppressive effect of Romidepsin in vivo. Romidepsin treatment led to a time- and dose-dependent induction of cell cycle arrest in the G2/M phase and apoptosis. G2/M phase arrest inhibited the proliferation of HCC cells by alterations in p21/cdc25C/cdc2/cyclinB proteins. Increased concentrations of Erk and JNK phosphorylations were observed in a dose-dependent manner in the Romidepsin group, but p38 phosphorylation was not affected. G2/M phase arrest and the apoptosis of HCC cells induced by Romidepsin were mediated by the activation of Erk/MAPK pathways and JNK/MAPK pathways. The tumor size was significantly larger in the negative control group compared to Romidepsin group and no significant loss in body weight was observed in the Romidepsin group. Our findings offer proof-of-concept for use of Romidepsin as a novel class of chemotherapy in the treatment of HCC.

Efficacy of docetaxel combined with oxaliplatin and fluorouracil against stage III/IV gastric cancer.

AIM: To investigate the clinical efficacy and toxic effects of neoadjuvant chemotherapy using docetaxel combined with oxaliplatin and fluorouracil for treating stage III/IV gastric cancer. METHODS: A total of 53 stage III/IV gastric cancer patients were enrolled into the study and treated with neoadjuvant chemotherapy. Two of the cases were excluded. The program was as follows: 75 mg/m(2) docetaxel and 85 mg/m(2) oxaliplatin on day 1 and 1500 mg/m(2) fluorouracil on days 1 to 3 for three weeks. RESULTS: The tumour changes, postoperative remission rate, changes in the symptoms and adverse reactions were observed. The overall clinical efficacy (complete remission + partial remission) of the neoadjuvant chemotherapy was 62.7%. R0 radical resection was performed on 60.8% of the patients, with a remission rate (pathological complete response + pathological subtotal response + pathological partial response) of 74.2%. The Karnofksy score improved in 42 cases. The toxicity reactions mostly included myelosuppression, followed by gastrointestinal mucosal lesions, nausea, vomiting and diarrhoea. CONCLUSION: Neoadjuvant chemotherapy consisting of docetaxel combined with oxaliplatin and fluorouracil is effective for stage III/IV gastric cancer. However, the treatment is associated with a high incidence of bone marrow suppression, which should be managed clinically.