Oxymatrine, the main alkaloid component in the traditional Chinese herbal medicine Sophora japonica (Sophora flavescens Ait), has been reported to have antitumor properties. However, the mechanisms of action in human pancreatic cancer are not well established to date. In the present study, we investigated the antiangiogenic effects of oxymatrine on human pancreatic cancer as well as the possible mechanisms involved. The results of the cell viability assay showed that treatment of PANC-1 pancreatic cancer cells with oxymatrine resulted in cell growth inhibition in a dose- and time-dependent manner. To investigate the possible mechanisms involved in these events, we performed western blotting and reverse transcription-polymerase chain reaction (RT-PCR) analysis. The results revealed that oxymatrine decreased the expression of angiogenesis-associated factors, including nuclear factor κB (NF-κB) and vascular endothelial growth factor (VEGF). Finally, the antiproliferative and antiangiogenic effects of oxymatrine on human pancreatic cancer were further confirmed in pancreatic cancer xenograft tumors in nude mice. In conclusion, our studies for the first time suggest that oxymatrine has potential antitumor effects on pancreatic cancer via suppression of angiogenesis, probably through regulation of the expression of the NF-κB-mediated VEGF signaling pathway.

Oridonin, an active component isolated from Rabdosia rubescens, has been reported to exhibit antitumor effects. In the present study, we evaluated the antitumor activity and the mechanisms of action of oridonin in pancreatic cancer. Oridonin treatment significantly induced apoptotic cell death in SW1990 pancreatic cancer cells in a dose-dependent manner. Additionally, cell apoptosis was markedly inhibited by PFT α (pifithrin α), a p53-specific inhibitor, which was applied to evaluate the function of p53, showing that p53 was responsible for the cytotoxity of oridonin. Moreover, oridonin increased the expression of p-p53 with a concomitant increase in p21 in the SW1990 cells. Following treatment with mitogen-activated protein kinase (MAPK) inhibitors, PD98059 (ERK inhibitor), SP600125 (JNK inhibitor) and SB203580 (p38 inhibitor), the cytotoxity of oridonin was not influenced by JNK (SP600125) and ERK (PD98059), but these effects were opposite to the cytotoxity of oridonin observed with SP203580 treatment. These findings confirmed that orodonin-induced apoptosis was p38-dependent, but JNK- and ERK-independent. Furthermore, the activation of the p38 kinase promoted the activation of p53 and its downstream target p21, and further caused caspase-9 and -3 activation, as demonstrated by evidence showing that the p38 inhibitor SB203580 not only blocked the phosphorylation of p38 but also reduced the activation of p53, p21 and caspase-9 and -3. Collectively, these results suggest that p53-dependent and caspase-dependent induction of p38 MAPK directly participates in apoptosis induced by oridonin.

Gemcitabine resistance is a common problem of pancreatic cancer chemotherapy, and how to reverse it plays an important role in the treatment of pancreatic cancer. This study investigated the effect of emodin on the gemcitabine-resistant pancreatic cancer cell line SW1990/Gem, and explored the potential mechanism of its action. SW1990/Gem was obtained by culture of the pancreatic cancer cell line SW1990 in vitro by intermittently increasing the concentration of gemcitabine in the culture medium for 10 months, observing the morphology using inverted microscopy. SW1990/Gem cells were pretreated with emodin (10 μM) for different periods followed by treatment with gemcitabine (20 μM) for 48 h; cell proliferation was tested by MTT assay. SW1990/Gem cells were treated by emodin with different concentrations for 48 h, cell apoptosis was detected by flow cytometry (FCM). The expression of gene and protein, such as MDR-1 (P-gp), NF-κB, Bcl-2, Bax, cytochrome-C (cytosol), caspase-9 and -3 were measured by RT-PCR and Western blotting. The function of P-gp in SW1990/Gem cells was checked by FCM. The results showed that the SW1990/Gem cells changed greatly in morphology and the resistance index was 48.63. Emodin promoted cell apoptosis of the gemcitabine-resistant cell line SW1990/Gem in a dose-dependent manner. Emodin enhanced the SW1990/Gem cell sensitivity to gemcitabine in a time-dependent manner. Emodin monotherapy or combination with gemcitabine both decreased the gene and protein expression levels of MDR-1 (P-gp), NF-κB and Bcl-2 and inhibited the function of P-gp, but increased the expression levels of Bax, cytochrome-C (cytosol), caspase-9 and -3, and promoted cell apoptosis. This demonstrated that emodin had a reversing effect on the gemcitabine-resistant cell line SW1990/Gem, possibly via decreasing the function of P-gp and activating the mitochondrial apoptosis pathway in vitro.

Abstract. Capsaicin, one of the major pungent ingredients found in red peppers, has been recently demonstrated to induce apoptosis in various malignant cell lines through an unclear mechanism. In this study, the effect of capsaicin on proliferation and apoptosis in the human pancreatic cancer cell line PANC-1 and its possible mechanism(s) of action were investigated. The results of a Cell Counting Kit-8 (CCK-8) assay revealed that capsaicin significantly decreased the viability of PANC-1 cells in a dose-dependent manner. Capsaicin induced G0/G1 phase cell cycle arrest and apoptosis in PANC-1 cells as demonstrated by a flow cytometric assessment. Caspase-3 expression at both the protein and mRNA level was promoted following capsaicin treatment. Furthermore, we revealed that phospho-PI3 Kinase p85 (Tyr458) and phospho-Akt (Ser473) in PANC-1 cells were downregulated in response to capsaicin. Moreover, capsaicin gavage significantly inhibited the growth of pancreatic cancer PANC-1 cell xenografts in athymic nude mice. An increased number of TUNEL-positive cells and cleaved caspase-3 were observed in capsaicin-treated mice. In vivo, capsaicin downregulated the expression of phospho-PI3 Kinase p85 (Tyr458) and phospho-Akt (Ser473).In conclusion, we have demonstrated that capsaicin is an inhibitor of growth of PANC-1 cells, and downregulation of the phosphoinositide 3-kinase/Akt pathway may be involved in capsaicin-induced apoptosis in vitro and in vivo.

Gemcitabine is currently the best treatment available for pancreatic cancer (PaCa); however, patients with the disease develop resistance to the drug over time. Agents that can either enhance the effects of gemcitabine or overcome chemoresistance to the drug are required for the treatment of PaCa. Oridonin is one such agent which is safe and multitargeted, and has been linked with the suppression of survival, proliferation, invasion and angiogenesis of cancer. In this study, we investigated whether oridonin could sensitize PaCa to gemcitabine in vitro and in vivo. In vitro, oridonin inhibited the proliferation of the PaCa cell line, BxPC-3, potentiated the apoptosis induced by gemcitabine, induced G1 cell cycle arrest and activated p38 and p53; these results were significant when oridonin was combined with gemcitabine. In vivo, we found that oridonin significantly suppressed tumor growth and this effect was further enhanced by gemcitabine (P<0.05). Tumors from nude mice injected with BxPC-3 PaCa cells and treated with a combination of oridonin and gemcitabine showed a significant upregulation in p38 and p53 activation (P<0.05 vs. control, P<0.05 vs. gemcitabine or oridonin alone). Taken together, our results demonstrate that oridonin can potentiate the effects of gemcitabine in PaCa through the mitogen-activated protein kinase (MAPK)-p38 signaling pathway, which is dependent on p53 activation.

When assessed as a categorical variable, LNR was the most powerful method to predict survival for Stage II-III RC patients with limited TNLN. Rather, LODDS was the most accurate staging system regardless of the TNLN when LN status was modeled as continuous variable.

5-Aza-2′-deoxycytidine (5-Aza-CdR) is currently acknowledged as a demethylation drug, and causes a certain degree of demethylation in a variety of cancer cells, including pancreatic cancer cells. Emodin, a traditional Chinese medicine (TCM), is an effective monomer extracted from rhubarb and has been reported to exhibit antitumor activity in different manners in pancreatic cancer. In the present study, we examined whether emodin caused demethylation and increased the demethylation of three tumor-suppressor genes P16, RASSF1A and ppENK with a high degree of methylation in pancreatic cancer when combined with 5-Aza-CdR. Our research showed that emodin inhibited the growth of pancreatic cancer Panc-1 cells in a dose- and time-dependent manner. Dot-blot results showed that emodin combined with 5-Aza-CdR significantly suppressed the expression of genome 5mC in PANC-1 cells. In order to verify the effect of methylation, methylation-specific PCR (MSP) and bisulfite genomic sequencing PCR (BSP) combined with TA were selected for the cloning and sequencing. Results of MSP and BSP confirmed that emodin caused faint demethylation, and 5-Aza-CdR had a certain degree of demethylation. When emodin was combined with 5-Aza-CdR, the demethylation was more significant. At the same time, fluorescent quantitative PCR and western blot analysis results confirmed that when emodin was combined with 5-Aza-CdR, the expression levels of P16, RASSF1A and ppENK were increased more significantly compared to either treatment alone. In contrast, the expression levels of DNA methyltransferase 1 (DNMT1) and DNMT3a were more significantly reduced with the combination treatment than the control or either agent alone, further proving that emodin in combination with 5-Aza-CdR enhanced the demethylation effect of 5-Aza-CdR by reducing the expression of meth-yltransferases. In conclusion, the present study confirmed that emodin in combination with 5-Aza-CdR enhanced the demethylation by 5-Aza-CdR of tumor-suppressor genes p16, RASSF1A and ppENK by reducing the expression of methyltransferases DNMT1 and DNMT3a.

Capsaicin, main pungent ingredient of hot chilli peppers, has been shown to have anticarcinogenic effect on various cancer cells through multiple mechanisms. In this study, we investigated the apoptotic effect of capsaicin on human pancreatic cancer cells in both in vitro and in vivo systems, as well as the possible mechanisms involved. In vitro, treatment of both the pancreatic cancer cells (PANC-1 and SW1990) with capsaicin resulted in cells growth inhibition, G0/G1 phase arrest, and apoptosis in a dose-dependent manner. Knockdown of growth arrest- and DNA damage-inducible gene 153 (GADD153), a marker of the endoplasmic-reticulum-stress- (ERS-) mediated apoptosis pathway, by specific siRNA attenuated capsaicin-induced apoptosis both in PANC-1 and SW1990 cells. Moreover, in vivo studies capsaicin effectively inhibited the growth and metabolism of pancreatic cancer and prolonged the survival time of pancreatic cancer xenograft tumor-induced mice. Furthermore, capsaicin increased the expression of some key ERS markers, including glucose-regulated protein 78 (GRP78), phosphoprotein kinase-like endoplasmic reticulum kinase (phosphoPERK), and phosphoeukaryotic initiation factor-2α (phospho-eIF2α), activating transcription factor 4 (ATF4) and GADD153 in tumor tissues. In conclusion, we for the first time provide important evidence to support the involvement of ERS in the induction of apoptosis in pancreatic cancer cells by capsaicin.