Jeff Yi-Fu Chen

4β-Hydroxywithanolide E from Physalis peruviana (golden berry) inhibits growth of human lung cancer cells through DNA damage, apoptosis and G2/M arrest

BackgroundThe crude extract of the fruit bearing plant, Physalis peruviana (golden berry), demonstrated anti-hepatoma and anti-inflammatory activities. However, the cellular mechanism involved in this process is still unknown.MethodsHerein, we isolated the main pure compound, 4β-Hydroxywithanolide (4βHWE) derived from golden berries, and investigated its antiproliferative effect on a human lung cancer cell line (H1299) using survival, cell cycle, and apoptosis analyses. An alkaline comet-nuclear extract (NE) assay was used to evaluate the DNA damage due to the drug.ResultsIt was shown that DNA damage was significantly induced by 1, 5, and 10 μg/mL 4βHWE for 2 h in a dose-dependent manner (p < 0.005). A trypan blue exclusion assay showed that the proliferation of cells was inhibited by 4βHWE in both dose- and time-dependent manners (p < 0.05 and 0.001 for 24 and 48 h, respectively). The half maximal inhibitory concentrations (IC50) of 4βHWE in H1299 cells for 24 and 48 h were 0.6 and 0.71 μg/mL, respectively, suggesting it could be a potential therapeutic agent against lung cancer. In a flow cytometric analysis, 4βHWE produced cell cycle perturbation in the form of sub-G1 accumulation and slight arrest at the G2/M phase with 1 μg/mL for 12 and 24 h, respectively. Using flow cytometric and annexin V/propidium iodide immunofluorescence double-staining techniques, these phenomena were proven to be apoptosis and complete G2/M arrest for H1299 cells treated with 5 μg/mL for 24 h.ConclusionsIn this study, we demonstrated that golden berry-derived 4βHWE is a potential DNA-damaging and chemotherapeutic agent against lung cancer.

Serine protease inhibitor (SERPIN) B1 promotes oral cancer cell motility and is over-expressed in invasive oral squamous cell carcinoma

Lymph node metastasis is the hallmark of malignant neoplasms in patients of oral cancer, accounting for the poor diagnosis and reduced 5-year survival rate. Here we sought to identify cell motility-associated proteins of oral cancer by proteomic approach. We compared the proteomes of two oral cancer cells, CAL-27 and SAS, with the highest and the lowest migration potential, respectively, amongst six different oral cancer cell lines. Subsequent identification of differentially expressed proteins by LC-MS/MS and Western analysis revealed that SERPINB1 (serine protease inhibitor, clade B, member1) was highly expressed in CAL-27, the high-motility oral cancer cells. Semi-quantitative and real-time PCR further confirmed differential expression of SERPINB1 in these two cell lines at mRNA level. To verify the motility-promoting function of SERPINB1 in oral cancer cells, we showed that endogenous expression of SERPINB1 correlated positively with cell migration. Moreover, ectopic expression of SERPINB1 in oral cancer cells, SAS, Ca9-22, CAL-27 and HSC-3, increased cell migration by 25%, 52%, 90% and 100%, respectively. Finally, we found that the expression of SERPINB1 was significantly higher in 5 of 8 (62.5%) oral cancer tissues compared with the matched adjacent normal tissues. Besides, immunohistochemical results indicated over-expression of SERPINB1 in clinicopathologically invasive oral squamous cell carcinoma (OSCC) but not in normal oral mucosa (p<0.01). Together, our findings have provided a possible biomarker for oral cancer metastasis.

p38 MAPK and NF-κB pathways are involved in naphtho[1,2-b] furan-4,5-dione induced anti-proliferation and apoptosis of human hepatoma cells

Naphtho[1,2-b] furan-4,5-dione (NFD) was investigated for its anti-proliferation effect on human hepatocellular carcinoma (HCC), Hep3B, HepG(2), and Huh-7 cells. The effect of NFD on inhibiting proliferation and apoptosis was correlated with up-regulation of pro-apoptotic protein and down-regulation of pro-survival proteins. Remarkably, we found that NFD inhibited the nuclear translocation of NF-kappaB, likely accounting for the down-regulation of pro-survival Bcl-2 family. Furthermore, suppression of p38 MAPK activity by a specific inhibitor significantly rescued the cell proliferation inhibited by NFD. These findings suggest that signaling imbalance between p38 MAPK and NF-kappaB by NFD results in the proliferative inhibition and apoptosis of HCC tumor cells.

Reversine suppresses oral squamous cell carcinoma via cell cycle arrest and concomitantly apoptosis and autophagy

BackgroundThe effective therapies for oral cancer patients of stage III and IV are generally surgical excision and radiation combined with adjuvant chemotherapy using 5-Fu and Cisplatin. However, the five-year survival rate is still less than 30% in Taiwan. Therefore, evaluation of effective drugs for oral cancer treatment is an important issue. Many studies indicated that aurora kinases (A, B and C) were potential targets for cancer therapies. Reversine was proved to be a novel aurora kinases inhibitor with lower toxicity recently. In this study, the potentiality for reversine as an anticancer agent in oral squamous cell carcinoma (OSCC) was evaluated.MethodsEffects of reversine on cell growth, cell cycle progress, apoptosis, and autophagy were evaluated mainly by cell counting, flow cytometry, immunoblot, and immunofluorescence.ResultsThe results demonstrated that reversine significantly suppressed the proliferation of two OSCC cell lines (OC2 and OCSL) and markedly rendered cell cycle arrest at G2/M stage. Reversine also induced cell death via both caspase-dependent and -independent apoptosis. In addition, reversine could inhibit Akt/mTORC1 signaling pathway, accounting for its ability to induce autophagy.ConclusionsTaken together, reversine suppresses growth of OSCC via multiple mechanisms, which may be a unique advantage for developing novel therapeutic regimens for treatment of oral cancer in the future.

Fern plant-derived protoapigenone leads to DNA damage, apoptosis, and g2/m arrest in lung cancer cell line H1299

Protoapigenone, isolated from the native fern plant Thelypteris torresiana, has anticancer activity against some cancer cells. However, the toxicological mechanism for protoapigenone is still unknown. Here, we investigated the anticancer effect of protoapigenone on human lung cancer cell lines. The comet assay showed that DNA damage induced by protoapigenone is dose-dependent. Trypan blue exclusion showed that the cell killing by protoapigenone is both time and dose dependent. The IC(50) of protoapigenone for 12, 24, and 48 h in H1299 cells is 6.11, 2.74, and 1.49 microM, respectively. Flow cytometry showed cell cycle perturbation such as sub-G(1) accumulation (at 1.57 microM for 48 h and at 3.57 microM for 12 and 24 h) and G(2)/M arrest (at 3.57 microM for 12 and 24 h) for protoapigenone. The sub-G(1) accumulation phenomena in the 3.57 microM for 24 h sample were shown to be apoptosis using Annexin V-immunofluorescence/propidium iodide staining. These results suggest protoapigenone is a potential chemotherapeutic agent for lung cancers.

Ling-Zhi Polysaccharides Potentiate Cytotoxic Effects of Anticancer Drugs against Drug-Resistant Urothelial Carcinoma Cells

The combined effects of ling-zhi polysaccharide fraction 3 (LZP-F3) and anticancer drugs (cisplatin and arsenic trioxide) were examined in three human urothelial carcinoma (UC) cells (parental, NTUB1; cisplatin-resistant, N/P(14); and arsenic-resistant, N/As(0.5)). MTT assay and median-effect analysis revealed that LZP-F3 could profoundly reverse the chemosensitivity of N/P(14) and N/As(0.5) to cisplatin and arsenic, respectively, in a dose-dependent manner, which involved activation of p38 and down-regulation of Akt and XPA. A dose of 10 mug/mL of LZP-F3 induced significant G1 arrest in N/P(14) and N/As(0.5) cells by flow cytometry, which may be mediated by the induction of p21(WAF1/CIP1). The combination of LZP-F3 and arsenic trioxide produced a significant synergistic growth inhibition of NTUB1 and N/As(0.5) cells. Similar results were also found in N/P(14) cells. These molecular events of combined effects involved significant and earlier induction of Fas, caspase 3 and 8 activation, Bax and Bad up-regulation, Bcl-2 and Bcl-x(L) down-regulatuion, and cytochrome c release.

Proteomic Analysis of Anti-Tumor Effects of 11-Dehydrosinulariolide on CAL-27 Cells

The anti-tumor effects of 11-dehydrosinulariolide, an active ingredient isolated from soft coral Sinularia leptoclados, on CAL-27 cells were investigated in this study. In the MTT assay for cell proliferation, increasing concentrations of 11-dehydrosinulariolide decreased CAL-27 cell viability. When a concentration of 1.5 μg/mL of 11-dehydrosinulariolide was applied, the CAL-27 cells viability was reduced to a level of 70% of the control sample. The wound healing function decreased as the concentration of 11-dehydrosinulariolide increased. The results in this study indicated that treatment with 11-dehydrosinulariolide for 6 h significantly induced both early and late apoptosis of CAL-27 cells, observed by flow cytometric measurement and microscopic fluorescent observation. A comparative proteomic analysis was conducted to investigate the effects of 11-dehydrosinulariolide on CAL-27 cells at the molecular level by comparison between the protein profiling (revealed on a 2-DE map) of CAL-27 cells treated with 11-dehydrosinulariolide and that of CAL-27 cells without the treatment. A total of 28 differential proteins (12 up-regulated and 16 down-regulated) in CAL-27 cells treated with 11-dehydrosinulariolide have been identified by LC-MS/MS analysis. Some of the differential proteins are associated with cell proliferation, apoptosis, protein synthesis, protein folding, and energy metabolism. The results of this study provided clues for the investigation of biochemical mechanisms of the anti-tumor effects of 11-dehydrosinulariolide on CAL-27 cells and could be valuable information for drug development and progression monitoring of oral squamous cell carcinoma (OSCC).

Protective Effect of Caffeic Acid on Paclitaxel Induced Anti-Proliferation and Apoptosis of Lung Cancer Cells Involves NF-κB Pathway

Caffeic acid (CA), a natural phenolic compound, is abundant in medicinal plants. CA possesses multiple biological effects such as anti-bacterial and anti-cancer growth. CA was also reported to induce fore stomach and kidney tumors in a mouse model. Here we used two human lung cancer cell lines, A549 and H1299, to clarify the role of CA in cancer cell proliferation. The growth assay showed that CA moderately promoted the proliferation of the lung cancer cells. Furthermore, pre-treatment of CA rescues the proliferation inhibition induced by a sub-IC50 dose of paclitaxel (PTX), an anticancer drug. Western blot showed that CA up-regulated the pro-survival proteins survivin and Bcl-2, the down-stream targets of NF-κB. This is consistent with the observation that CA induced nuclear translocation of NF-κB p65. Our study suggested that the pro-survival effect of CA on PTX-treated lung cancer cells is mediated through a NF-κB signaling pathway. This may provide mechanistic insights into the chemoresistance of cancer calls.

Cytotoxic effects of Echinacea purpurea flower extracts and cichoric acid on human colon cancer cells through induction of apoptosis

ETHNOPHARMACOLOGICAL RELEVANCE Echinacea is a top-selling herbal supplement that acts as immunostimulant. It has been used to treat common cold, coughs, bronchitis and upper respiratory infections. It is also a popular product used in anticancer therapy. The cytotoxic effects of Echinacea on cancer cells are still not clear. The aims of this study were to provide a preliminary validation of the effects of 50% aqueous ethanol extract of Echinacea purpurea flowers and its major compound, cichoric acid, on human colon cancer cells Caco-2 and HCT-116. MATERIALS AND METHODS The cytotoxic effects of Echinace flower extracts and cichoric acid on cell viability, telomerase activity, DNA fragmentation, β-catenin, caspase-9, and cleavage of poly-ADP-ribose polymerase (PARP) of human colon cancer cell were examined. RESULTS The results showed a significant inhibition of proliferation in E. purpurea flower extract and cichoric acid in a dose- and time-dependent manner. Cichoric acid treatment decreased telomerase activity in HCT-116 cells. Moreover, cichoric acid effectively induced apoptosis in colon cancer cells, which were characterized by DNA fragmentation, activation of caspase-9, cleavage of PARP and downregulation of β-catenin. CONCLUSIONS Our data indicate that cichoric acid has a strong growth-inhibitory effect against colon cancer cells, presumably resulting from the reduced telomerase activity and the induction of apoptosis. The exact mechanism of action should still be determined in future studies. Overall, the effects of 50% aqueous ethanol extract of E. purpurea flowers and cichoric acid may have provided in vitro evidence for the use as chemotherapeutic agents.

Decreased GRP78 Protein Expression is a Potential Prognostic Marker of Oral Squamous Cell Carcinoma in Taiwan

BACKGROUND/PURPOSE Oral squamous cell carcinoma (OSCC) is an aggressive tumor and its occurrence in Taiwan is closely related to chronic smoking, alcohol consumption, and especially to betel quid chewing. It became the fourth most common malignant tumor of Taiwanese men in 2006. Unfortunately, there are few biomarkers for diagnosis and treatment of this disease. METHODS To find potential markers, two domestic cell lines (OC2 and OCSL) derived from different grades of OSCC were established and their proteins were compared by global proteomic analysis. The expression differences of GRP78 protein in these two cell lines and clinical samples from OSCC patients were verified. RESULTS Of the 11 candidate proteins expressed differentially in both cell lines, six [heat shock protein 90 kDa beta member 1 (94 kDa glucose-regulated protein; GRP94), protein disulfide-isomerase precursor, vimentin, tubulin beta-2C chain, 78 kDa glucose-regulated protein precursor (GRP78), and annexin A2] were increased in OC2 cells (low-grade OSCC), and five (heat shock protein 90-beta, annexin A1, stress-induced phosphoprotein 1, elongation factor-2, and integrin alpha-3 precursor) were increased in OCSL cells (high-grade OSCC). Some of these proteins have been previously associated with malignant tumors, but no previous association of GRP78 with OSCC has been reported. GRP78 protein expression in these two OSCC cell lines was confirmed by Western blotting. Immunohistochemical staining of clinical samples from OSCC patients revealed that decreased GRP78 protein expression was significantly correlated with advance tumor stage (p < 0.001) and neck lymph node metastasis (p = 0.001). CONCLUSION GRP78 protein is a possible biomarker of oral cancer in Taiwan.