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Cancer development and progression are extremely complex due to the alteration of various genes and pathways. In most cases, multiple agents are required to control cancer progression. The purpose of this study is to investigate, using a mouse model, the synergistic interactions of anti-cancer agents, 1'-S-1'-acetoxychavicol acetate (ACA), Mycobacterium indicus pranii (MIP), and cisplatin (CDDP) in double and triple combinations to treat chemo-sensitize and immune-sensitize breast cancer. Changes in tumor volume and body weight were monitored. Organs were harvested and stained using hematoxylin-eosin for histopathological assessment. Milliplex enzyme-linked immunosorbent assay (ELISA) was performed to determine cytokine levels, while immunohistochemistry (IHC) was conducted on tumor biopsies to verify systemic drug effects. In vivo mouse models showed tumor regression with maintenance of regular body weight for all the different treatment regimens. IHC results provided conclusive evidence indicating that combination regimens were able to down-regulate nuclear factor kappa-B activation and reduce the expression of its regulated pro-inflammatory proteins. Reduction of pro-inflammatory cytokines (e.g., IL-6, TNF-α, and IFN-ɣ) levels were observed when using the triple combination, which indicated that the synergistic drug combination was able to significantly control cancer progression. In conclusion, ACA, MIP, and CDDP together serve as promising candidates for further development and for subsequent clinical trials against estrogen-sensitive breast cancer.

Nine analogs of 1' S -1'-acetoxychavicol acetate (ACA) were hemi-synthesized and evaluated for their anticancer activities against seven human cancer cell lines. The aim of this study was to investigate the anti-proliferative, apoptotic, and anti-migration effects of these compounds and to explore the plausible underlying mechanisms of action. We found that ACA and all nine analogs were non toxic to human mammary epithelial cells (HMECs) used as normal control cells, and only ACA, 1'-acetoxyeugenol acetate (AEA), and 1'-acetoxy-3,5-dimethoxychavicol acetate (AMCA) inhibited the growth of MDA-MB-231 breast cancer cells with a half-maximal inhibitory concentration (IC 50 ) value of <30.0 μM based on 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay results, and were selected for further investigation. DNA fragmentation assays showed that these three compounds markedly induced apoptosis of MDA-MB-231 cells. Western blot analysis revealed increased expression levels of cleaved PARP, p53, and Bax, while decreased expression levels of Bcl-2 and Bcl-xL were seen after treatment, indicating that apoptosis was induced via the mitochondrial pathway. Moreover, ACA, AEA, and AMCA effectively inhibited the migration of MDA-MB-231 cells. They also downregulated the expression levels of pFAK/FAK and pAkt/Akt via the integrin β1-mediated signaling pathway. Collectively, ACA and its hemi-synthetic analogs, AEA and AMCA are seen as potential anticancer agents following their abilities to suppress growth, induce apoptosis, and inhibit migration of breast cancer cells., Competing Interests: Disclosure The authors report no conflicts of interest in this work.

The extracellular signal-regulated kinase (ERK) signaling pathway is essential for cell proliferation and is frequently deregulated in human tumors such as melanoma. Melanoma remains incurable despite the use of conventional chemotherapy; consequently, development of new therapeutic agents for melanoma is highly desirable. Here, we carried out a chemical genetic screen using a fission yeast phenotypic assay and showed that ACA-28, a synthetic derivative of 1'-acetoxychavicol acetate (ACA), which is a natural ginger compound, effectively inhibited the growth of melanoma cancer cells wherein ERK MAPK signaling is hyperactivated due to mutations in the upstream activating regulators. ACA-28 more potently inhibited the growth of melanoma cells than did the parental compound ACA. Importantly, the growth of normal human epidermal melanocytes (NHEM) was less affected by ACA-28 at the same 50% inhibitory concentration. In addition, ACA-28 specifically induced apoptosis in NIH/3T3 cells which were oncogenically transformed with human epidermal growth factor receptor-2 (HER2/ErbB2), but not in the parental cells. Notably, the ACA-28-induced apoptosis in melanoma and HER2-transformed cells was abrogated when ERK activation was blocked with a specific MEK inhibitor U0126. Consistently, ACA-28 more strongly stimulated ERK phosphorylation in melanoma cells, as compared in NHEM. ACA-28 might serve as a promising seed compound for melanoma treatment., (© 2017 Molecular Biology Society of Japan and John Wiley & Sons Australia, Ltd.)

MicroRNAs (miRNAs) are short non-coding RNAs that regulate genes posttranscriptionally. Past studies have reported that miR-210 is up-regulated in many cancers including cervical cancer, and plays a pleiotropic role in carcinogenesis. However, its role in regulating response towards anti-cancer agents has not been fully elucidated. We have previously reported that the natural compound 1'S-1'-acetoxychavicol acetate (ACA) is able to induce cytotoxicity in various cancer cells including cervical cancer cells. Hence, this study aims to investigate the mechanistic role of miR-210 in regulating response towards ACA in cervical cancer cells. In the present study, we found that ACA down-regulated miR-210 expression in cervical cancer cells, and suppression of miR-210 expression enhanced sensitivity towards ACA by inhibiting cell proliferation and promoting apoptosis. Western blot analysis showed increased expression of mothers against decapentaplegic homolog 4 (SMAD4), which was predicted as a target of miR-210 by target prediction programs, following treatment with ACA. Luciferase reporter assay confirmed that miR-210 binds to sequences in 3'UTR of SMAD4. Furthermore, decreased in SMAD4 protein expression was observed when miR-210 was overexpressed. Conversely, SMAD4 protein expression increased when miR-210 expression was suppressed. Lastly, we demonstrated that overexpression of SMAD4 augmented the anti-proliferative and apoptosis-inducing effects of ACA. Taken together, our results demonstrated that down-regulation of miR-210 conferred sensitivity towards ACA in cervical cancer cells by targeting SMAD4. These findings suggest that combination of miRNAs and natural compounds could provide new strategies in treating cervical cancer.

Seven new 6-methylsaligenin derivatives, including the trimeric peniphenylanes A-B (1-2) and dimeric peniphenylanes C-G (3-7), together with four known biogenetically related compounds (8-11) were discovered from the extract of the deep-sea-derived fungus Penicillium fellutanum HDN14-323. The structures of the new compounds were established through extensive analysis. Their cytotoxic activity against HeLa, HL-60, and HCT-116 cell lines was evaluated, with compound 4 exhibiting the best activity against the HeLa cell line (IC50 = 9.3 µM)., (Georg Thieme Verlag KG Stuttgart · New York.)

Although the introduction of bortezomib and immunomodulatory drugs has led to improved outcomes in patients with multiple myeloma, the disease remains incurable. In an effort to identify more potent and well-tolerated agents for myeloma, we have previously reported that 1'-acetoxychavicol acetate (ACA), a natural condiment from South-East Asia, induces apoptotic cell death of myeloma cells in vitro and in vivo through inhibition of NF-κB-related functions. Searching for more potent NF-κB inhibitors, we developed several ACA analogs based on quantitative structure-activity relationship analysis. TM-233, one of these ACA analogs, inhibited cellular proliferation and induced cell death in various myeloma cell lines with a lower IC50 than ACA. Treatment with TM-233 inhibited constitutive activation of JAK2 and STAT3, and then downregulated the expression of anti-apoptotic Mcl-1 protein, but not Bcl-2 and Bcl-xL proteins. In addition, TM-233 rapidly decreased the nuclear expression of NF-κB and also decreased the accumulation of cytosolic NF-κB. We also examined the effects of TM-233 on bortezomib-resistant myeloma cells that we recently established, KMS-11/BTZ and OPM-2/BTZ. TM-233, but not bortezomib, inhibited cellular proliferation and induced cell death in KMS-11/BTZ and OPM-2/BTZ cells. Interestingly, the combination of TM-233 and bortezomib significantly induced cell death in these bortezomib-resistant myeloma cells through inhibition of NF-κB activity. These results indicate that TM-233 could overcome bortezomib resistance in myeloma cells mediated through different mechanisms, possibly inhibiting the JAK/STAT pathway. In conclusion, TM-233 might be a more potent NF-κB inhibitor than ACA, and could overcome bortezomib resistance in myeloma cells., (© 2015 The Authors. Cancer Science published by Wiley Publishing Asia Pty Ltd on behalf of Japanese Cancer Association.)

It has been suggested that the combined effect of natural products may improve the effect of treatment against the proliferation of cancer cells. In this study, we evaluated the combination of 1'-acetoxychavicol acetate (ACA), obtained from Alpinia galangal, and sodium butyrate, a major short chain fatty acid, on the growth of HepG2 human hepatocellular carcinoma cells and found that treatment had a synergistic inhibitory effect. The number of HepG2 cells was synergistically decreased via apoptosis induction when cells were treated with both ACA and sodium butyrate. In ACA- and sodium butyrate-treated cells, intracellular reactive oxygen species (ROS) levels and NADPH oxidase activities were increased significantly. The decrease in cell number after combined treatment of ACA and sodium butyrate was diminished when cells were pretreated with catalase. These results suggest that an increase in intracellular ROS levels is involved in cancer cell death. AMP-activated protein kinase (AMPK), a cellular energy sensor, plays an essential role in controlling processes related to tumor development. In ACA- and sodium butyrate-treated cells, AMPK phosphorylation was induced significantly, and this induction improved when cells were pretreated with catalase. These results suggest that the increase in intracellular ROS is involved in the increase of AMPK phosphorylation. In normal hepatocyte cells, treatment with ACA and sodium butyrate did not decrease cell numbers or increase ROS levels. In conclusion, combined treatment with ACA and sodium butyrate synergistically induced apoptotic cell death via an increase in intracellular ROS and phosphorylation of AMPK. Our findings may provide new insight into the development of novel combination therapies against hepatocellular carcinoma., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

1'-Acetoxychavicol acetate (ACA), extracted from rhizomes of tropical ginger, possesses antitumor properties against a wide variety of malignancies. MicroRNAs have been found to act as oncogenes and as tumor suppressor genes in the development of cancer. The purpose of this study was to investigate the miRNA involved in the molecular mechanisms of ACA action on tumor inhibition. It was found that ACA significantly inhibited the growth of human head and neck squamous cell carcinoma cell line HN4 and induced cell apoptosis. Further studies indicated that ACA downregulated the expression of miR-23a in HN4 cells. Transfection with anti-miR-23a inhibited the proliferation of HN4 cells and induced cell apoptosis. In addition, phosphatase and tensin homolog deleted on chromosome 10 (PTEN) was confirmed to be the target of miR-23a. Taken together, our findings suggest that ACA might have anticancer effects against human head and neck cancer through downregulation of miR-23a, which can repress tumor suppressor PTEN.

A stereoselective route for the total synthesis of anticancer marine natural product (+)-varitriol (1) is detailed herein. The impressive biological activity and interesting structural features of natural (+)-varitriol fuelled us to undertake the synthesis of some higher analogues (1a-j) of this molecule. The key features of the synthetic strategy include one-pot Wittig olefination followed by a highly diastereoselective oxa-Michael addition to assemble stereochemically pure tetrasubstituted THF moiety of the natural varitriol and olefin cross metathesis to couple the aromatic part with tetrasubstituted THF moiety. The total synthesis of title natural product is efficient with 21.8% overall yield for 9 linear steps from D-ribose and thus facilitates the more scaled-up practical route for the synthesis of 1 and its analogues as well. The synthetic (+)-varitriol (1) and its analogues were screened for their cytotoxicity. The present synthetic approach paves the way for preparation of numerous analogues of the title natural product for drug development.

1'-Acetoxychavicol acetate (ACA), isolated from the rhizomes and the seeds of the Zingiberaceae plant, has a variety of biological activities such as antitumor, antiallergic and repellent effects. However, ACA seems to have some disadvantages which may limit for future possible clinical applications, for example, its poor water solubility. Furthermore, ACA is not stable in aqueous solutions and undergoes hydrolysis and/or isomerization. To improve the solubility and stability of ACA in water, we prepared the inclusion complexes with various β-cyclodextrins (β-CDs).In aqueous solution, the association constants of ACA with various CDs were estimated at 662±95 (β-CD), 336±70 (methyl-β-CD, Meβ-CD), and 322±44M(-1) (hydroxypropyl-β-CD, HPβ-CD), respectively, by a spectrofluorometric displacement method based on competition between a guest and a fluorescent probe for CDs. It was revealed that almost all ACAs existed as a free molecule in the CD-containing aqueous solution. However, in the case of preparing the inclusion complexes of CDs with ACA by a solid phase 'high-speed vibration milling' technique, the average inclusion rates of the obtained water-soluble complexes were calculated as 88±13% (β-CD), 70±1% (Meβ-CD), and 63±2% (HPβ-CD), respectively, by (1)H NMR analysis. To characterize the structures of the CD·ACA complexes, 2,3,6-trimethyl-β-CD (TMeβ-CD)·ACA complex was prepared as a model compound (inclusion rate: 40%). As a result of 2D ROESY experiments, it was considered that the aromatic ring of ACA is located in the narrow side of the hydrophobic cavity of the TMeβ-CD and both 1'- and 4-acetoxy groups of ACA positioned in the vicinity of the secondary and primary methoxy groups of TMeβ-CD, respectively. Furthermore, we examined the apoptogenic activity of CD·ACA complexes to evaluate whether or not the bioactivities of ACA were affected by their inclusion. Although the cytotoxicity of all CD·ACA complexes in human epithelial carcinoma HeLa cells and murine adenocarcinoma colon26 cells were diminished as compared with the ACA alone, only HPβ-CD·ACA maintained high levels of activity. In addition, HPβ-CD·ACA, and Meβ-CD·ACA showed suppressive effect for the transcription factor NF-κB activation on LPS-activated murine macrophage RAW264.7 cells and the former was more active complex. Furthermore, HPβ-CD·ACA inhibited the in vivo tumor growth of tumor-bearing mice, although the activity was slightly weak compared with that of free ACA. These results indicate that HPβ-CD is the best host molecule for ACA to form a water-soluble complex with the similar biological activity of free ACA., (Copyright © 2011. Published by Elsevier Ltd.)

A series of novel 2-(5-(hydroxymethyl)-3-phenyl-1H-pyrazol-1-yl)-1-phenylethanol derivatives (4) was synthesized from ethyl 1-(2-oxo-2-phenylethyl)-3-phenyl-1H-pyrazole-5-carboxylate derivatives (3) and characterized by means of IR, 1H NMR, HRMS and X-ray crystal diffraction. Structures of 4a, 4d, 4e and 4f were also determined by 13C NMR. Isomeric intermediates, 3a and 5a, were unambiguously confirmed by X-ray crystal structure analysis and successfully differentiated with 1H NMR chemical shifts of methylene bonded to pyrazole ring. Preliminary biological evaluation showed that compounds 4d and 4e could suppress A549 lung cancer cell growth through cell cycle arrest and autophagy., (Copyright © 2010 Elsevier Masson SAS. All rights reserved.)

1'-(S)-1'-Acetoxychavicol acetate (ACA) isolated from the Malaysian ethno-medicinal plant Alpinia conchigera Griff. was investigated for its potential as an anticancer drug. In this communication, we describe the cytotoxic and apoptotic properties of ACA on five human tumour cell lines. Data from MTT cell viability assays indicated that ACA induced both time- and dose-dependent cytotoxicity on all tumour cell lines tested and had no adverse cytotoxic effects on normal cells. Total mortality of the entire tumour cell population was achieved within 30 hrs when treated with ACA at 40.0 µM concentration. Flow cytometric analysis for annexin-V and PI dual staining demonstrated that cell death occurred via apoptosis, followed by secondary necrosis. The apoptotic effects of ACA were confirmed via the DNA fragmentation assay, in which consistent laddering of genomic DNA was observed for all tumour cell lines after a 24 hrs post-treatment period at the IC(50) concentration of ACA. A cell cycle analysis using PI staining also demonstrated that ACA induced cell cycle arrest at the G(0)/G(1) phase, corresponding to oral tumour cell lines. In conclusion, ACA exhibits enormous potential for future development as a chemotherapeutic drug against various malignancies.

Background: NF-kappaB is a survival signaling transcription factor complex involved in the malignant phenotype of many cancers, including squamous cell carcinomas (SCC). The citrus coumarin, auraptene (AUR), and the ethno-medicinal ginger (Alpinia galanga) phenylpropanoid, 1'-acetoxychavicol acetate (ACA), were previously shown to suppress 12-O-tetradecanoylphorbol-13-acetate (TPA) induced mouse skin tumor promotion. The goal of the present study was to determine whether AUR and ACA are effective either alone or in combination with all-trans retinoic acid (ATRA) for suppressing SCC tumor growth., Methods: We first determined the effects of orally administered ACA (100 mg/kg bw) and AUR (200 mg/kg bw) on lipopolysaccharide (LPS)-induced NF-kappaB activation in NF-kappaB-RE-luc (Oslo) luciferase reporter mice. Dietary administration of AUR and ACA +/- ATRA was next evaluated in a xenograft mouse model. Female SCID/bg mice were fed diets containing the experimental compounds, injected with 1 x 106 SRB12-p9 cells s.c., palpated and weighed twice a week for 28 days following injection., Results: Both ACA and AUR suppressed LPS-induced NF-kappaB activation in the report mice. In the xenograft model, AUR (1000 ppm) and ACA (500 ppm) modestly suppressed tumor volume. However, in combination with ATRA at 5, 10, and 30 ppm, ACA 500 ppm significantly inhibited tumor volume by 56%, 62%, and 98%, respectively. The effect of ATRA alone was 37%, 33%, and 93% inhibition, respectively. AUR 1000 ppm and ATRA 10 ppm were not very effective when administered alone, but when combined, strongly suppressed tumor volume by 84%., Conclusions: Citrus AUR may synergize the tumor suppressive effects of ATRA, while ACA may prolong the inhibitory effects of ATRA. Further studies will be necessary to determine whether these combinations may be useful in the control of human SCC.

Nine new gentisyl alcohol derivatives, namely, the trimeric terrestrol A (8), dimeric terrestrols B-H (1-7), and a monomeric derivative (12), together with four known analogues (9-11, 13) were isolated from the marine-derived fungus Penicillium terrestre. The structures of the new compounds were elucidated by spectroscopic methods including one- and two-dimensional NMR as well as low- and high-resolution mass spectrometric analysis. These new compounds (1-8, 12) showed cytotoxic effects on HL-60, MOLT-4, BEL-7402, and A-549 cell lines with IC50 values in the range 5-65 microM. Compound 6 also showed moderate inhibitory activity against protein tyrosine kinases (Src and KDR). Furthermore, all new compounds exhibited moderate radical scavenging activity against DPPH with IC50 values in the range 2.6-8.5 microM.

The design, synthesis, and initial biological evaluation of a doxorubicin prodrug that contains a dual tumor specific moiety, which allows enhanced tumor recognition potential, is reported. Both a tumor-specific recognition site and a tumor selective enzymatic activation sequence are incorporated in the prodrug. The first tumor-specific sequence is the bicyclic CDCRGDCFC (RGD-4C) peptide that selectively binds alpha v beta 3 and alpha v beta 5 integrins. These integrins are highly overexpressed on invading tumor endothelial cells. The second tumor-specific sequence is a D-Ala-Phe-Lys tripeptide that is selectively recognized by the tumor-associated protease plasmin, which is involved in tumor invasion and metastasis. An aminocaproyl residue was incorporated as a spacer between the two peptide sequences, whereas a self-eliminating 4-aminobenzyl alcohol spacer was inserted between the plasmin substrate and doxorubicin. Although the prodrug showed a decreased binding affinity as compared with the unconjugated reference peptide, it was still a potent ligand for alpha v beta 3 and alpha v beta 5 integrin receptors. The synthesized construct also possessed plasmin substrate properties as demonstrated by doxorubicin release from 1 upon incubation with plasmin. The release of doxorubicin from 1 was not complete, possibly related to low prodrug solubility. In vitro prodrug 1 showed plasmin-dependent cytotoxicity for endothelial cells and HT1080 fibrosarcoma cells. On the basis of these in vitro results, derivatives of 1 with improved water solubility are considered good candidates for additional development and in vivo evaluation of this dual targeting concept.

The direct effect of selected cytostatic drugs on natural killer (NK) cell activity was evaluated. Peripheral blood mononuclear cells from healthy donors were tested for their cytolytic activity in vitro in the presence of adriamycin, methotrexate, leucovorin, vincristin, cytosine arabinoside and teniposide. Most of the tested cytostatic drugs did not show to be active at concentrations comparable to their plasma level. However, diluents of some preparations (cytosine arabinoside, teniposide) containing organic solutions and stabilizing additives (e.g. benzyl alcohol) suppressed the NK activity more than chemotherapeutic agents alone. Thus teniposide, containing such additives, inhibited NK activity already at 5 mg/ml, while its peak plasma concentration was 23.8 mg/ml. The inhibitory concentrations of teniposide did not affect the target binding of effector cells and the expression of 14 tested leukocyte differentiation markers. This implies that a postbinding step of the lytic process was altered by the preparation. Likewise, no inhibition of lectin dependent cellular cytotoxicity by teniposide and its diluent was observed, suggesting that the lectin may substitute the missing lytic signal.