Involvement of the mitochondrial pathway in bruceine D-induced apoptosis in Capan-2 human pancreatic adenocarcinoma cells

Abstract

Abstract. The fruit of Brucea javanica L. is a common herb used in Chinese medicine for the treatment of a variety of cancers. Our research group has previously identified bruceine D (BD), a quassinoid found abundantly in B. javanica, to have potent cytotoxic effect on a number of pancreatic cancer cell lines, including Panc-1, SW1990 and Capan-1 cells. In the present study, we showed that BD was also able to inhibit the growth of the Capan-2 human pancreatic adenocarcinoma cell line, but it exerted only modest cytotoxicity on the WRL68 human hepatocyte cell line and a human pancreatic progenitor cell line. The antiproliferative effects of BD were comparable to those exhibited by camptothecin and gemcitabine in our culture system. We found a dose-dependent decrease of the mitochondrial membrane potential in BD-treated Capan-2 cells as measured by the JC-1 assay. BD exposure was able to attenuate the expression of Bcl-2 protein in Capan-2 cells as detected by western blot analysis. In addition, the expression of both caspase 9 and caspase 3 in BD-treated Capan-2 cells was significantly accentuated. Moreover, BD was capable of inducing the fragmentation of genomic DNA in Capan-2 cells as evidenced by Hoechst staining. Cell cycle analysis demonstrated that BD could increase the percentage of Capan-2 cells in the subG 1 phase in a dose-related manner. An increase in the apoptosis of Capan-2 cells was also observed by Annexin V and PI staining. These results unequivocally indicate that BD induces cytotoxicity in Capan-2 cells via the induction of cellular apoptosis involving the mitochondrial pathway. IntroductionHuman pancreatic cancer is a gastrointestinal malignancy with extremely poor prognosis owing to a lack of early clinical diagnosis and its intrinsic resistance to radiotherapy and chemotherapy (1,2). According to the Hong Kong Cancer Registry in 2009 pancreatic cancer was the 8th and 6th major cause of cancer-related deaths in males and females, respectively. As for the management of pancreatic cancer, surgical resection remains the only potentially curative treatment of pancreatic cancer. However, only 5-25% of the patients diagnosed with pancreatic cancer were operable, and chemotherapy thus remains the mainstay of palliative management for the locally advanced and metastatic stage of this cancer. The median disease-free survival following complete resection of the pancreatic tumor and adjuvant chemotherapy with the first line chemotherapeutic agent gemcitabine is 13.4 and 6.9 months, respectively (3-6). Although camptothecin has a positive effect on arresting pancreatic tumor growth, many unwanted sideeffects limit its clinical application (5,7). All these dismal data highlight an urgent need for new therapeutic agents that could produce better clinical outcomes for this deadly disease.Our previous studies have shown that the fruit of Brucea javanica L., a Chinese medicinal plant commonly used for cancer treatment, has potent in vitro anti-pancreatic cancer activity (8). Furthermore, bruceine D (BD), a qu...

Apoptosis induced by bruceine�D in human non‑small‑cell lung cancer cells involves mitochondrial ROS‑mediated death signaling

“…Therefore, treatment of A549 cells with bruceine D inhibited the cell cycle transition from the G1 to the S phase, suggesting that inhibition of cell cycle progression may be one of the mechanisms through which bruceine D inhibits the proliferation of A549 NSCLC cells. The present results are consistent with those of previous studies demonstrating that bruceine D induces G1 phase arrest in cancer cell lines (6,10).…”

“…bruceine D, one of the major active quassinoids isolated from B. javanica , has been reported to exert an inhibitory effect against several types of cancer (8,22,23). In our previous research, bruceine D was found to exhibit a prominent suppressive effect on the proliferation of various pancreatic cancer cells, displaying only modest cytotoxicity against normal tissue cell lines, including GES-1 cells, human pancreatic progenitor cells and the WRL68 human hepatocyte cell line (6,8-10). Furthermore, bruceine D administration at a high dose (3 mg/kg) was associated with no obvious toxicity or distant organ metastasis in mice (8).…”

“…Our previous studies have demonstrated that bruceine D exerts potent antiproliferative effects on cultured human pancreatic adenocarcinoma cells through induction of apoptosis involving the activation of the p38-MAPK, NF-κB, and reactive oxygen species (ROS)-associated PI3K/Akt signaling pathways (6-8). By contrast, bruceine D was shown to exert only mild cytotoxic effects on human gastric mucosal epithelial GES-1 cells, human foreskin fibroblast Hs68 cells and the WRL68 human hepatocyte cell line (8-10). Furthermore, bruceine D effectively reduced the rate of xeno-graft human pancreatic tumor and orthotopic xenograft in nude mice, with no overt toxicity (7,8).…”

ABHD5 blunts the sensitivity of colorectal cancer to fluorouracil via promoting autophagic uracil yield

“…This can explain why the content of uracil showed a remarkable increase in control SW480 cells but a little shift in ABHD5 knockdown SW480 cells under the challenge of FU. To date, different pharmacological autophagy inhibitors have been developed and used in clinical cancer therapy 35–39 . Different autophagy inhibitors block the autophagic process at different stages.…”

Basic research Suppression of human hepatocellular cancer cell proliferation by Brucea javanica oil-loaded liposomes via induction of apoptosis

“…Brucea javanica oil emulsion can induce apoptosis of the bladder cancer cell line BIU-87 and human promyelocytic leukemia cell line HL-60 [ 21 , 22 ]. It was also found that BJOE can induce apoptosis of human pancreatic adenocarcinoma cells [ 23 ]. However, BJOE has been used with a high concentration and thus the toxic effects of BJOE on the normal cells are relatively high.…”