Activation of Caspase‐9/3 and Inhibition of Epithelial Mesenchymal Transition are Critically Involved in Antitumor Effect of Phytol in Hepatocellular Carcinoma Cells

This study was designed to investigate the antitumor mechanism of Phytol in hepatocellular carcinomas including Huh7 and HepG2 cells in association with caspase dependent apoptosis and epithelial mesenchymal transition (EMT) signaling. Phytol significantly suppressed the viability of Huh7 and HepG2 cells. Also, Phytol significantly increased the sub G1 population and terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end labeling (TUNEL) positive cells in a concentration dependent manner in Huh7 and HepG2 cells. Consistently, Phytol cleaved poly (adenosine diphosphate‐ribose) polymerase (PARP), activated caspase‐9/3, and Bax attenuated the expression of survival genes such as Bcl‐2, Mcl‐1, and c‐Myc in Huh7 and HepG2 cells. Of note, Phytol also suppressed typical morphology change of EMT such as loss of cell adhesion and formation of fibroblast like mesenchymal cells in HepG2 cells. Furthermore, Phytol also reversed the loss of E‐cadherin and overexpression of p‐smad2/3, alpha‐smooth muscle actin, and Snail induced by EMT promoter transforming growth factor beta1 in HepG2 cells. Overall, our findings suggest that Phytol exerts antitumor activity via apoptosis induction through activation of caspas‐9/3 and inhibition of EMT in hepatocellular carcinoma cells as a potent anticancer candidate for liver cancer treatment. Copyright © 2015 John Wiley & Sons, Ltd.     

[6]‐Gingerol enhances the cisplatin sensitivity of gastric cancer cells through inhibition of proliferation and invasion via PI3K/AKT signaling pathway

Cisplatin‐based chemotherapy is a widely used chemotherapeutic regimen for gastric cancer; however, drug resistance limits its efficacy. [6]‐Gingerol has been found to exhibit anticancer effects. Here, we aim to explore the potential of [6]‐gingerol in combination with cisplatin as a new regimen for gastric cancer. CCK‐8 assay and colony formation assay were used to determine the effect of [6]‐gingerol in combination with cisplatin on cell viability of gastric cancer cells. Flow cytometry was performed to assess cell cycle distribution. Wound‐healing assay and transwell invasion assay were conducted to examine the migration and invasion abilities. Cell cycle and invasion‐related proteins and mRNAs, as well as PI3K/AKT signaling proteins, were assessed by western blotting and quantitative real‐time polymerase chain reaction. Combination of [6]‐gingerol with cisplatin inhibited cell viability and enhanced cell cycle arrest at G1 phase compared with cisplatin alone. The combination treatment inhibited cell migration and invasion ability and decreased cyclin D1, cyclin A2, matrix metalloproteinase‐9, p‐PI3K, AKT, and p‐AKT protein expressions and increased P21 and P27 mRNA levels. Our study demonstrates that [6]‐gingerol enhances the cisplatin sensitivity of gastric cancer cells and that the mechanisms involve G1 phase arrest, migration and invasion suppression via PI3K/AKT signaling pathway.     

Dihydroartemisinin,an antimalarial drug,induces absent in melanoma 2 inflammasome activation and autophagy in human hepatocellular carcinoma HepG2215 cells

As an effective antimalarial drug, Dihydroartemisinin (DHA) is readily isolated from the traditional Chinese medicine of Artemisia annua. DHA is not only an autophagy promoter but also a substance with strong antitumor efficiency. The relationship between autophagy and inflammasomes has been suggested in hepatocellular carcinoma (HCC). However, there are few reports describing relationships between inflammasomes and autophagy in HCC therapy. The present study demonstrated that DHA suppressed cell proliferation in HepG2215 cells in a dose‐ and time‐dependent manner. The inhibitory activity is mediated by autophagy, in which reactive oxygen species (ROS) production induced nuclear and mitochondrial DNA damage. Then, DHA were first shown to promote AIM2/caspase‐1 inflammasome. Compared with the DHA group, the autophagy inhibitor 3‐MA significantly inhibited the expressions of activated Caspase‐1, a pyroptotic marker proteins. Meanwhile, repression of mTOR by rapamycin promoted autophagy and AIM2/caspase‐1 activation. The caspase‐1 inhibitor Z‐YVAD‐FMK also notably blocked autophagy cell death characterized by the downexpression of Beclin‐1 and LC3‐II. Additionally, the study demonstrated that DHA suppressed pseudopodium formation and cell mobility. Therefore, we first reveal a novel mechanism that DHA promotes AIM2/caspase‐1 inflammasome, which contributes to autophagy in HepG2215 cells. Moreover, nuclear and mitochondrial DNA damage was also involved in this process via ROS production.     

Neferine,an alkaloid from lotus seed embryo targets HeLa and SiHa cervical cancer cells via pro‐oxidant anticancer mechanism

Apoptosis and autophagy are important processes that control cellular homeostasis and have been highlighted as promising targets for novel anticancer drugs. This study aims to investigate the inhibitory effects and mechanisms of Neferine (Nef), an alkaloid from the lotus seed embryos of Nelumbo nucifera (N. nucifera), as a dual inducer of apoptosis and autophagy through the reactive oxygen species (ROS) activation in cervical cancer cells. Nef and N. nucifera extract suppressed the cell viability of HeLa and SiHa cells in a dose‐dependent manner. Importantly, Nef showed minimal toxicity to normal cells. Furthermore, Nef inhibited anchorage‐independent growth, colony formation and migration ability of cervical cancer cells. Nef induces mitochondrial apoptosis by increasing pro‐apoptotic protein bax, cytochrome‐c, cleaved caspase‐3 and caspase‐9, poly‐ADP ribose polymerase (PARP) cleavage, DNA damage (pH₂AX) while downregulating Bcl‐2, procaspase‐3 and procaspase‐9, and TCTP. Of note, apoptotic effect by Nef was significantly attenuated in the presence of N‐acetylcysteine (NAC), suggesting pro‐oxidant activity of this compound. Nef also promoted autophagy induction through increasing beclin‐1, atg‐4, atg‐5 and atg‐12, LC‐3 activation, and _P62/SQSTM1 as determined by western blot analysis. Collectively, these results demonstrate that Nef is a potent anticancer compound against cervical cancer cells through inducing apoptosis and autophagic pathway involving ROS.     

Flavonoids of Korean Citrus aurantium L. Induce Apoptosis via Intrinsic Pathway in Human Hepatoblastoma HepG2 Cells

Korean Citrus aurantium L. has long been used as a medicinal herb for its anti‐inflammatory, antioxidant, and anticancer properties. The present study investigates the anticancer role of flavonoids extracted from C. aurantium on human hepatoblastoma cell, HepG2. The Citrus flavonoids inhibit the proliferation of HepG2 cells in a dose‐dependent manner. This result was consistent with the in vivo xenograft results. Apoptosis was detected by cell morphology, cell cycle analysis, and immunoblot. Flavonoids decreased the level of pAkt and other downstream targets of phosphoinositide‐3‐kinase/Akt pathway – P‐4EBP1 and P‐p70S6K. The expressions of cleaved caspase 3, Bax, and Bak were increased, while those of Bcl‐2 and Bcl‐xL were decreased with an increase in the expression of Bax/Bcl‐xL ratio in treated cells. Loss of mitochondrial membrane potential was also observed in flavonoid‐treated HepG2 cells. It was also observed that the P‐p38 protein level was increased both dose and time dependently in flavonoid‐treated cells. Collectively, these results suggest that flavonoid extracted from Citrus inhibits HepG2 cell proliferation by inducing apoptosis via an intrinsic pathway. These findings suggest that flavonoids extracted from C. aurantium L. are potential chemotherapeutic agents against liver cancer. Copyright © 2015 John Wiley & Sons, Ltd.     

Tanshinone IIA Induces Autophagic Cell Death via Activation of AMPK and ERK and Inhibition of mTOR and p70 S6K in KBM‐5 Leukemia Cells

Although tanshinone IIA (Tan IIA) from Salviae miltiorrhizae was known to induce apoptosis in various cancers, its underlying mechanism of autophagic cell death was not reported yet. Thus, in the present study, the molecular mechanism of autophagic cell death by Tan IIA was investigated in KBM‐5 leukemia cells. Tan IIA significantly increased the expression of microtubule‐associated protein light chain 3 (LC3) II as a hallmark of autophagy in western blotting and immunofluorescence staining. Tan IIA augmented the phosphorylation of adenosine monophosphate‐activated protein kinase (AMPK) and attenuated the phosphorylation of mammalian target of rapamycin (mTOR) and p70 S6K in a dose‐dependent manner. Conversely, autophagy inhibitor 3‐methyladenine partly reversed the cytotoxicity and the phosphorylation of AMPK, mTOR and p70 S6K induced by Tan IIA in KBM‐5 leukemia cells. In addition, Tan IIA dramatically activated the extracellular signal regulated kinase (ERK) signaling pathway including Raf, ERK and p90 RSK in a dose‐dependent and time‐dependent manner. Consistently, ERK inhibitor PD184352 suppressed LC3‐II activation induced by Tan IIA, whereas PD184352 and PD98059 did not affect poly (ADP‐ribose) polymerase cleavage and sub‐G1 accumulation induced by Tan IIA in KBM‐5 leukemia cells. Furthermore, Tan IIA could induce autophagy via LC3‐II activation in various cancer cells such as prostate (PC‐3), multiple myeloma (U266), lung (NCI‐H460), and breast (MDA‐MB‐231) cells. Overall, these findings suggest that Tan IIA induces autophagic cell death via activation of AMPK and ERK and inhibition of mTOR and p70 S6K in KBM‐5 cells as a potent natural compound for leukemia treatment. Copyright © 2013 John Wiley & Sons, Ltd.     

Ursolic acid promotes apoptosis,autophagy, and chemosensitivity in gemcitabine‐resistant human pancreatic cancer cells

Gemcitabine (GEM) resistance in pancreatic adenocarcinoma mediated by the receptor for advanced glycation end products (RAGE) has been demonstrated. Therefore, investigating the safety and the potential of new auxiliary methods for pancreatic cancer treatment is urgent. Ursolic acid (UA), a natural pentacyclic triterpenoid found in apple peels, rosemary, and thyme, has been reported to have anticancer capacity. This study aimed to reveal the underlying mechanisms of UA in cell death and drug enhancement, especially in GEM‐resistant pancreatic cancer cells. First, GEM‐resistant cells (MIA Paca‐2^GEMR cells) were established by incrementally increasing GEM culture concentrations. UA treatment reduced cell viability through cell cycle arrest and endoplasmic reticulum (ER) stress, resulting in apoptosis and autophagy in a dose‐dependent manner in MIA Paca‐2 and MIA Paca‐2^GEMR cells. High RAGE expression in MIA Paca‐2^GEMR cells was suppressed by UA treatment. Interestingly, knocking down RAGE expression showed similar UA‐induced effects in both cell lines. Remarkably, UA had a drug‐enhancing effect by decreasing cell viability and increasing cell cytotoxicity when combined with GEM treatment. In conclusions, UA triggered ER stress, subsequently regulating apoptosis‐ and autophagy‐related pathways and increasing GEM chemosensitivity in pancreatic cancer cells by inhibiting the expression of RAGE.     

Retracted: Ganoderic acid A alleviates hypoxia‐induced apoptosis,autophagy, and inflammation in rat neural stem cells through the PI3K/AKT/mTOR pathways

Effects of ganoderic acid A (GAA), a lanostane triterpene, on hypoxia‐ischemia encephalopathy (HIE) remain unclear. We aimed to figure out the specific role of GAA in hypoxia‐treated neural stem cells (NSCs) as well as the regulatory mechanisms. Primary rat NSCs were incubated under hypoxia to simulate HIE. Viability and apoptosis of hypoxia‐injured NSCs were measured by cell counting kit‐8 and flow cytometry assays, respectively. Proteins related to apoptosis, autophagy, and the PI3K/AKT/mTOR pathways were evaluated by Western blot analysis. LY294002 and rapamycin were added to inhibit the PI3K/AKT pathway and mTOR pathway, respectively. Enzyme‐linked immunosorbent assay was carried out to test the release of proinflammatory cytokines. We found that hypoxia‐induced decrease of cell viability, increases of apoptotic cells and autophagy, and the release of IL‐6, IL‐1β, and TNF‐α were all attenuated by GAA stimulation. Activation of caspases induced by hypoxia was alleviated by GAA. Furthermore, we found that inhibition of the PI3K/AKT pathway eliminated the effects of GAA on apoptosis and proinflammatory cytokines release in hypoxia‐injured NSCs. Meanwhile, inhibition of the mTOR pathway abrogated the effects of GAA on cell autophagy in hypoxia‐injured NSCs. In conclusion, GAA alleviated hypoxia‐induced injury in NSCs might be through activating the PI3K/AKT and mTOR pathways.     

芥子碱硫氰酸盐增强HepG2细胞对吉西他滨敏感性的作用

目的探讨芥子碱硫氰酸盐增强人肝癌细胞HepG2对吉西他滨敏感性的作用及分子机制。方法应用计算机分子对接技术分析芥子碱硫氰酸盐结合多耐药性相关蛋白ABCB1和ABCG2的能力,罗丹明123实验检测芥子碱硫氰酸盐对HepG2细胞外排药物能力的影响,CCK-8、克隆形成实验、流式细胞术分别检测芥子碱硫氰酸盐联合吉西他滨对HepG2细胞增殖、克隆形成、凋亡的影响,Western blot实验检测芥子碱硫氰酸盐联合吉西他滨对HepG2细胞中ABCB1、ABCG2、活化半胱天冬酶-8(Cleave caspase-8)、B淋巴细胞瘤-2基因(Bcl-2)、凋亡相关基因(Bax)表达的影响。结果芥子碱硫氰酸盐可稳定结合多耐药性相关蛋白ABCB1、ABCG2,降低HepG2细胞外排药物的能力,增强吉西他滨对HepG2细胞增殖和克隆形成的抑制作用(P<0.05)及吉西他滨诱导HepG2凋亡的能力(P<0.05),抑制ABCB1、ABCG2蛋白表达,增强吉西他滨诱导的Bcl-2表达减少及Cleave caspase8、Bax表达增加(P<0.05)。结论芥子碱硫氰酸盐能靶向抑制多耐药相关蛋白ABCB1和ABCG2,增强肝癌HepG2细胞对吉西他滨的敏感性。     

Curcumin Induces Autophagy in ACC‐MESO‐1 Cells

Malignant pleural mesothelioma is known to be widely resistant to therapy and new treatment strategies are needed. Curcumin, which has a long history as a dietary spice is known to suppress the growth of multiple cancer lines, but the effects on mesothelioma cells are not well defined. In the present study we examined the effects of curcumin on ACC‐MESO‐1, which is a human derived mesothelioma cell line. We found that curcumin dose‐dependently reduced cell viability but did not induce apoptosis. Curcumin administration increased LC3B‐II/LC3B‐I expression, and induced the formation of autophagosomes on electron microscopy. These changes were attenuated by RNA silencing of atg5. From these findings it was speculated that induction of autophagy was at least in part involved in the reduction of cell viability by curcumin. Copyright © 2012 John Wiley & Sons, Ltd.     

1,7‐Bis(4‐hydroxyphenyl)‐4‐hepten‐3‐one from Betula platyphylla induces apoptosis by suppressing autophagy flux and activating the p38 pathway in lung cancer cells

Betula platyphylla (BP) is frequently administered in the treatment of various human diseases, including cancers. This study was undertaken to investigate the pharmacological function of the active components in BP and the underlying mechanism of its chemotherapeutic effects in human lung cancer cells. We observed that BP extracts and 1,7‐bis(4‐hydroxyphenyl)‐4‐hepten‐3‐one (BE1), one of the components of BP, effectively decreased the cell viability of several lung cancer cell lines. BE1‐treated cells exhibited apoptosis induction and cell cycle arrest at the G2/M phase. Further examination demonstrated that BE1 treatment resulted in suppression of autophagy, as evidenced by increased protein expression levels of both LC3 II and p62/SQSTM1. Interestingly, the pharmacological induction of autophagy with rapamycin remarkably reduced the BE1‐induced apoptosis, indicating that apoptosis induced by BE1 was associated with autophagy inhibition. Our data also demonstrated that BE1 exposure activated the p38 pathway resulting in regulation of the pro‐apoptotic activity. Taken together, we believe that BE1 is a potential anticancer agent for human lung cancer, which exerts its effect by enhancing apoptosis via regulating autophagy and the p38 pathway.     

Aloe‐emodin Induces Apoptosis in Human Liver HL‐7702 Cells through Fas Death Pathway and the Mitochondrial Pathway by Generating Reactive Oxygen Species

Aloe‐emodin (1,8‐dihydroxy‐3‐hydroxymethyl‐anthraquinone) is one of the primary active compounds in total rhubarb anthraquinones isolated from some traditional medicinal plants such as Rheum palmatum L. and Cassia occidentalis, which induce hepatotoxicity in rats. Thus, the aim of this study was to determine the potential cytotoxic effects and the underlying mechanism of aloe‐emodin on human normal liver HL‐7702 cells. The CCK‐8 assays demonstrated that aloe‐emodin decreased the viability of HL‐7702 cells in a dose‐dependent and time‐dependent manner. Aloe‐emodin induced S and G2/M phase cell cycle arrest in HL‐7702 cells. This apoptosis was further investigated by flow cytometry and nuclear morphological changes by DAPI staining, respectively. Moreover, aloe‐emodin provoked the production of intracellular reactive oxygen species and the depolarization of mitochondrial membrane potential (MMP). Further studies by western blot indicated that aloe‐emodin dose‐dependently up‐regulated the levels of Fas, p53, p21, Bax/Bcl‐2 ratio, and cleaved caspase‐3, ‐8, ‐9, and subsequent cleavage of poly(ADP‐ribose)polymerase (PARP). Taken together, these results suggest that aloe‐emodin inhibits cell proliferation of HL‐7702 cells and induces cell cycle arrest and caspase‐dependent apoptosis via both Fas death pathway and the mitochondrial pathway by generating reactive oxygen species, indicating that aloe‐emodin should be taken into account in the risk assessment for human exposure. Copyright © 2017 John Wiley & Sons, Ltd.     

Retracted: Ganoderic Acid A exerts the cytoprotection against hypoxia‐triggered impairment in PC12 cells via elevating microRNA‐153

Ganoderic Acid A (GAA) is often applied for healing cardiovascular and cerebrovascular ailments, but the influences in cerebral ischemia injury are still hazy. The research delved into the functions of GAA in hypoxia‐triggered impairment in PC12 cells. PC12 cells received hypoxia management for 12 hr, and subsequently, cell viability, migration, apoptosis, and correlative protein levels were assessed. After preprocessing with GAA, above cell behaviors were monitored again. The vector of microRNA (miR)‐153 inhibitor was utilized for PC12 cell transfection to further explore the functions of miR‐153 in hypoxia‐impaired cells. Pathways of phosphatidylinositol 3‐kinase (PI3K)/protein kinase B (AKT) and mammalian target of rapamycin (mTOR) were investigated via executing western blot for uncovering the latent mechanism. Results revealed that hypoxia disposition triggered PC12 cells impairment via restraining cell viability and migration and accelerating apoptosis. However, GAA visibly mollified hypoxia‐provoked impairment in PC12 cells. Interestingly, the enhancement of miR‐153 triggered by GAA was observed in hypoxia‐impaired PC12 cells. After miR‐153 inhibitor transfection, the protective functions of GAA in hypoxia‐impaired PC12 cells were dramatically inversed. Furthermore, GAA caused PI3K/AKT and mTOR activations via enhancement of miR‐153 in hypoxia‐impaired PC12 cells. The findings evinced that GAA exhibited the protective functions in PC12 cells against hypoxia‐evoked impairment through activating PI3K/AKT and mTOR via elevating miR‐153.     

Nerolidol Protects Against LPS‐induced Acute Kidney Injury via Inhibiting TLR4/NF‐κB Signaling

Acute kidney injury (AKI) is a critical care syndrome, resulting in acute reduction of renal function and up to 22% mortality of hospitalized patients. Nerolidol is a major component in several essential oils that possesses various pharmacological properties. The present study aimed to investigate the potential effect of nerolidol on lipopolysaccharide (LPS)‐induced AKI. Nerolidol dose‐dependently reduced the pathological injuries of kidney induced by LPS in rats. Nerolidol significantly decreased the levels of blood urea nitrogen and creatinine in LPS‐treated rats in a dose‐dependent manner. In addition, nerolidol inhibited LPS‐induced decrease of cell viability in NRK‐52E rat proximal tubular cells, which effect was concentration dependent. Nerolidol notably inhibited the increase of TNFα and IL‐1β in LPS‐treated rats and the mRNA expression of TNFα and IL‐1β in LPS‐treated NRK‐52E cells. Nerolidol suppressed the increase of toll‐like receptor 4 (TLR4) expression, phosphorylation and nuclear translocation of p65 NF‐κB in kidneys of LPS‐treated rats and LPS‐treated NRK‐52E cells. Overexpression of TLR4 and p65 NF‐κB significantly suppressed nerolidol‐induced inhibition of TNFα and IL‐1β expression and increase of cell viability in LPS‐treated cells. In summary, we found that nerolidol played a critical anti‐inflammatory effects through inhibition of TLR4/NF‐κB signaling and protected against LPS‐induced AKI. Copyright © 2017 John Wiley & Sons, Ltd.     

褐藻素诱导肝癌HepG2细胞凋亡和自噬的机制

目的：通过c-Jun氨基末端激酶（c-jun N-terminal kinase,JNK）信号通路来研究蹄叶橐吾醇化乙酸乙酯萃取物的抗炎作用机制。方法：采用噻唑蓝比色法（MTT法）测定倍比稀释的蹄叶橐吾醇化乙酸乙酯萃取物（浓度区间为0~640 mg·L^-1）作用于密度为5×10⁴个/mL的RAW264.7细胞24 h后的细胞活力,计算出药物对细胞的无毒浓度;测定JNK抑制剂SP600125（终浓度分别为25,12.5,6.25 μmol·L^-1）作用于细胞密度为5×10⁴个/mL的RAW264.7细胞24 h后的细胞活力,计算出SP600125作用的安全有效浓度;测定蹄叶橐吾醇化乙酸乙酯萃取物（终质量浓度分别为5,2.5,1 mg·L^-1）作用于LPS诱导细胞密度为5×10⁴个/mL的RAW264.7细胞12,24,36,48 h后的细胞活力,计算出药物抑制细胞增殖的浓度。采用蛋白质印迹（Western-blot）法测定蹄叶橐吾醇化乙酸乙酯萃取物（5 mg·L^-1）作用于LPS诱导的RAW264.7细胞24 h后p-JNK（磷酸化c-Jun氨基末端激酶）蛋白、JNK蛋白和环氧化酶-2（COX-2）蛋白的表达变化。结果：蹄叶橐吾醇化乙酸乙酯萃取物作用于LPS诱导的RAW264.7细胞,测定p-JNK,JNK,COX-2相对灰度值分别为：0.12±0.03,0.48±0.03,0.18±0.04,无药物作用的LPS诱导的RAW264.7细胞,测定p-JNK,JNK,COX-2,相对灰度值分别为：0.68±0.05,0.83±0.04,0.58±0.04,两组数据比较具有明显差异（P<0.01）。蹄叶橐吾醇化乙酸乙酯萃取物抑制LPS诱导的RAW264.7细胞增殖,下调p-JNK,JNK,COX-2等炎性蛋白的表达。结论：蹄叶橐吾醇化乙酸乙酯萃取物抗炎机制通过JNK信号通路来完成。     

Anti‐Proliferative Effects of Polyphenols from Pomegranate Rind (Punica granatum L.) on EJ Bladder Cancer Cells Via Regulation of p53/miR‐34a Axis

miRNAs and their validated miRNA targets appear as novel effectors in biological activities of plant polyphenols; however, limited information is available on miR‐34a mediated cytotoxicity of pomegranate rind polyphenols in cancer cell lines. For this purpose, cell viability assay, Realtime quantitative PCR for mRNA quantification, western blot for essential protein expression, p53 silencing by shRNA and miR‐34a knockdown were performed in the present study. EJ cell treatment with 100 µg (GAE)/mL PRE for 48 h evoked poor cell viability and caspase‐dependent pro‐apoptosis appearance. PRE also elevated p53 protein and triggered miR‐34a expression. The c‐Myc and CD44 were confirmed as direct targets of miR‐34a in EJ cell apoptosis induced by PRE. Our results provide sufficient evidence that polyphenols in PRE can be potential molecular clusters to suppress bladder cancer cell EJ proliferation via p53/miR‐34a axis. Copyright © 2015 John Wiley & Sons, Ltd.     

7,7'-Dimethoxyagastisflavone-induced apoptotic or autophagic cell death in different cancer cells

7,7'-Dimethoxyagastisflavone (DMGF), a biflavonoid isolated from the needles of Taxus × media cv. Hicksii, was evaluated for its antiproliferative and antineoplastic effects in three human cancer cell lines. Interestingly, DMGF caused cell death via different pathways in different cancer cells. DMGF induced apoptosis, activated caspase-3 activity and changed the mitochondrial membrane potential in HT-29 human colon cancer cells. However, the apoptotic pathway is not the major pathway involved in DMGF-induced cell death in A549 human lung cancer cells and HepG2 human hepatoma cells. Treatment with 3-MA, an inhibitor of autophagy, significantly decreased DMGF-induced cell death in HepG2 and A549 cells, but did not affect DMGF-induced cell death in HT-29 cells. Following DMGF treatment, the HepG2 cells increased expression of LC3B-II, a marker used to monitor autophagy in cells. Thus, DMGF induced apoptotic cell death in HT-29 cells, triggered both apoptotic and autophagic death in A549 cells and induced autophagic cell death in HepG2 cells.     

Distinct Responses of Cytotoxic Ganoderma lucidum Triterpenoids in Human Carcinoma Cells

The medicinal mushroom Ganoderma lucidum is well recognized for its effective cancer‐preventative and therapeutic properties, while specific components responsible for these anticancer effects are not well studied. Six triterpenoids that are ganolucidic acid E, lucidumol A, ganodermanontriol, 7‐oxo‐ganoderic acid Z, 15‐hydroxy‐ganoderic acid S, and ganoderic acid DM were isolated and identified from an extract of the mushroom. All compounds reduced cell growth in three human carcinoma cells (Caco‐2, HepG2, and HeLa cells) dose dependently with LC50s from 20.87 to 84.36 μM. Moreover, the six compounds induced apoptosis in HeLa cells with a maximum increase (22%) of sub‐G1 accumulations and 43.03% apoptotic cells in terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay (15‐hydroxy‐ganoderic acid S treatment). Apoptosis was further confirmed by annexin‐V staining. Four of the compounds also caused apoptosis in Caco‐2 cells with maximum 9.5% increase of sub‐G1 accumulations (7‐oxo‐ganoderic acid Z treatment) and maximum 29.84% apoptotic cells in TUNEL assay (ganoderic acid DM treatment). Contrarily, none of the compounds induced apoptosis in HepG2 cells. The different responses of the three cell lines following these treatments indicated that the bioactive properties of these compounds may vary from cells of different sites of origin and are likely acting under diverse regulatory mechanisms. Copyright © 2015 John Wiley & Sons, Ltd.     

Carvacrol induces cytotoxicity in human cervical cancer cells but causes cisplatin resistance: Involvement of MEK–ERK activation

Carvacrol has been shown to possess anticancer activity, but the mechanism is unknown, as well as the possibility of interaction with anticancer drugs. The aim of this study was to investigate the role of mitogen‐activated protein kinase kinase (MEK)/extracellular signal‐regulated kinase (ERK) signaling in carvacrol‐induced human cervical cancer HeLa cell cytotoxicity. In addition, we studied sensitization of HeLa cells to cisplatin (CP) by carvacrol. Both carvacrol and CP showed dose‐dependent cytotoxicity against HeLa cells and activated ERK1/2. The MEK inhibitor PD325901 suppressed ERK expression and further increased cytotoxicity of carvacrol but increased viability of CP‐treated cells by modulating apoptosis. The MEK inhibitor also increased microtubule‐associated protein 1A/1B‐light chain 3 beta expression in CP treatment. Cotreatment with CP and carvacrol resulted in increased viability of the cancer cells compared with CP treatment, which was associated with the suppression of apoptosis. MEK inhibition decreased the cell viability, without changes in apoptosis. Concomitantly, carvacrol increased CP‐induced expression of light chain 3 beta, which was enhanced by MEK inhibition. The results of the current study suggest the opposite role of ERK1/2 in carvacrol and CP‐induced HeLa cell cytotoxicity. Interestingly, carvacrol induced CP resistance in HeLa cells through ERK1/2‐independent suppression of apoptosis and ERK1/2‐dependent modulation of autophagy.