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Background: Triple-negative breast cancer (TNBC) recurrence and metastasis are the major causes of failure in TNBC therapy. The difficulties in treating TNBCs may be because of increased cancer cell plasticity that involves the fine-tuning of cellular redox homeostasis, mitochondrial bioenergetics, metabolic characteristics, and the development of cancer stem cells (CSCs)., Purpose: To investigate the effects and the underlying mechanisms of the phytosesquiterpene lactone deoxyelephantopin (DET) and its semi-synthesized derivative (DETD-35) in suppressing different phenotypic TNBC cell populations that contribute to tumor metastasis., Methods: A timelapse microfluidic-based system was established to analyze the effects of DETD-35 and DET on cell migration behavior in an oxygen gradient. Seahorse real-time cell metabolic analyzer and gas chromatography/quadrupole-time-of-flight mass spectrometry (GC/Q-TOF MS) were utilized to analyze the effects of the compounds on mitochondrial bioenergetics in TNBC cells. A miRNA knockout technique and miRNA sponges were employed to evaluate the miR-4284 involvement in the anti-TNBC cell effect of either compound., Results: DETD-35 and DET attenuated TNBC cell migration toward hypoxic regions under a 2-19 % oxygen gradient in a timelapse microfluidic-based system. DETD-35 and DET also suppressed CSC-like phenotypes, including the expression of Sox2, Oct4, and CD44 in TNBC cells under hypoxic conditions. DETD-35 and DET affected mitochondrial basal respiration, ATP production, proton leak, and primary metabolism, including glycolysis, the TCA cycle, and amino acid metabolism in the lung-metastatic TNBC cells. Furthermore, the expression of mitophagy markers PARKIN, BNIP3, PINK1, LC3-II, and apoptotic markers Bax, cleaved caspase 7, and cleaved PARP in hypoxic and lung-metastatic TNBC cells was also regulated by treatment with either compound. In miR-4284 knockout cells or miR-4284 inhibitor co-treated TNBC cells, DET- and DETD-35-induced over-expression of mitophagic and apoptotic markers was partially reversed, indicating miR-4284 involved with the compounds caused programmed cell death., Conclusion: This study demonstrated the novel activities of DETD-35 and DET in suppressing CSC-like phenotypes and metastatic TNBC cells through the de-regulation of mitochondrial bioenergetics., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2024 Elsevier GmbH. All rights reserved.)

Eight vilasinin-class limonoids, including the unusually chlorinated rubescins K-M ( 1 - 3 ), the 2,3-epoxylated rubescin N ( 4 ), and rubescins O-R ( 5 - 8 ), were newly isolated from Trichilia rubescens . The structures of the isolated compounds were determined through spectroscopic and spectrometric analyses, as well as ECD calculations. The natural occurrence of chlorinated limonoids 1 - 3 was confirmed by chemical methods and HPLC analysis of a roughly fractionated portion of the plant extract. Eight selected limonoids, including previously known and new compounds, were evaluated for antiproliferative activity against five human tumor cell lines. All tested limonoids, except 8 , exhibited significant potency, with IC 50 values of <10 μM; in particular, limonoid 14 strongly inhibited tumor cell growth, with IC 50 values of 0.54-2.06 μM against all tumor cell lines, including multi-drug-resistant cells.

The suppression of androgen receptor (AR) expression exacerbates the migration potential of prostate cancer. This study identified a previously unrecognized regulation of the AR-controlled pathway that promotes migration potential in prostate cancer cells. Prostate cancer cells that pass through a transwell membrane (mig cells) have a higher migration potential with a decreased AR expression than parental cells. In this study, we aimed to elucidate the mechanism of migration enhancement associated with the suppression of AR signaling. Expression of C-C motif ligand 20 (CCL20) is upregulated in mig cells, unlike in the parental cells. Knockdown of AR with small interfering RNA (siAR) in LNCaP and C4-2B cells increased CCL20 secretion and enhanced the migration of cancer cells. Mig cells, CCL20-treated cells, and siAR cells promoted cell migration with an enhancement of AKT phosphorylation and Snail expression, while the addition of a C-C chemokine receptor 6 (CCR6, the specific receptor of CCL20) inhibitor, anti-CCL20 antibody, and AKT inhibitor suppressed the activation of AKT and Snail. With 59 samples of prostate cancer tissue, CCL20 secretion was profuse in metastatic cases despite low AR expression levels. Snail expression was associated with the expression of CCL20 and CCR6. A xenograft study showed that the anti-CCL20 antibody significantly inhibited Snail expression, thereby suggesting a new therapeutic approach for castration-resistant prostate cancer with the inhibition of the axis between CCL20 and CCR6., (© 2022 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.)

A phytochemical study on Spermacoce ocymoides has led to the isolation of a novel bis-indole alkaloid, spermaocymine A (2), together with the known alkaloid 4-methyl-borreverine (1), as well as an anthraquinone, 8-hydroxy-2-(hydroxymethyl)-1-methoxyanthracene-9,10-dione (3). The structures of the isolated compounds were elucidated by analyzing spectroscopic and spectrometric data, including one-dimensional (1D)- and 2D-NMR and high resolution (HR)-MS. Newly isolated alkaloid 2 was a C-3,14-stereoisomer of 1, the first natural stereoisomer of related bis-indoles containing an indeno[1,2-b]indole skeleton with an epiminoethano bridge. When 1-3 were assayed against five tumor cell lines including multi-drug resistant cells, compound 1 exhibited potent antiproliferative activity with IC 50 values of 6.2-11.5 µM.

Cryptolaevilactones (CLs) A-L, found in the leaves and twigs of Cryptocarya laevigata, are unique natural meroterpenoids with a spiro[3.5]nonane skeleton. We report the total synthesis of a simplified model compound of CLs A-C. The synthetic route included introduction of a styryl group and coupling of a lactone moiety to a spiro ring system, which was constructed by a pinacol-like rearrangement.

The oxygen in the benzofuran (BF) of three antiproliferative natural neolignans, salvinal ( 1 ), obovaten ( 2 ), and 2-[7-methoxy-2-(4-methoxyphenyl)-3-methylbenzofuran-5-yl]ethanol ( 3 ), was replaced with sulfur to form the new biological scaffold benzothiophene (BT) thio-lignans 4 - 6 . Compounds 1 - 6 and 18 synthesized derivatives were evaluated for antiproliferative activity against five human cancer cell lines, including a multidrug-resistant cell line. Thio-salvinal ( 4 ) displayed significant antiproliferative effects with half-maximal inhibitory concentration (IC 50 ) values of 0.57-0.95 μM against all tested cell lines, except for the HER2 negative breast cancer cell line MCF-7. This thio-lignan was 6.5-9.4 times more potent than parent 1 . However, the related thio-lignans, 5 and 6 , showed much weaker antiproliferative effects than 4 and were less potent than the parent natural benzofuran lignans 2 and 3 . Newly synthesized thio-lignan 33 affected cell cycle progression at 24 and 48 h in the G2/M transition and S phase, respectively, as well as promoted sub-G1 induction by stimulating microtubule depolymerization and nuclear fragmentation. Since a highly reactive aldehyde in salvinal is generally not appropriate for drug development, we have successfully found nonaldehyde derivative 33 showing biological activity similar to salvinal by replacing BF with BT and an aldehyde with 1,3-dioxolane.

α-Trifluoromethyl chalcones were prepared and evaluated for their antiproliferative activities against androgen-independent prostate cancer cell lines as well as five additional types of human tumor cell lines. The most potent chalcone 5 showed superior antitumor activity in vivo with both oral and intraperitoneal administration at 3 mg/kg. Cell-based mechanism of action studies demonstrated that 5 induced cell accumulation at sub-G1 and G2/M phases without interfering with microtubule polymerization. Furthermore, several cancer cell growth-related proteins were identified by using chalcone 5 as a bait for the affinity purification of binding proteins.

Melanoma is a highly metastatic disease with an increasing rate of incidence worldwide. It is treatment refractory and has poor clinical prognosis; therefore, the development of new therapeutic agents for metastatic melanoma are urgently required. In this study, we created a lung-seeking A375LM5 IF4g/Luc BRAF V600E mutant melanoma cell clone and investigated the bioefficacy of a plant sesquiterpene lactone deoxyelephantopin (DET) and its novel semi-synthetic derivative, DETD-35, in suppressing metastatic A375LM5 IF4g/Luc melanoma growth in vitro and in a xenograft mouse model. DET and DETD-35 treatment inhibited A375LM5 IF4g/Luc cell proliferation, and induced G 2 /M cell-cycle arrest and apoptosis. Furthermore, A375LM5 IF4g/Luc exhibited clonogenic, metastatic and invasive abilities, and several A375LM5 IF4g/Luc metastasis markers, N -cadherin, MMP 2 , vimentin and integrin α4 were significantly suppressed by treatment with either compound. Interestingly, DET- and DETD-35-induced Reactive Oxygen Species (ROS) generation and glutathione (GSH) depletion were found to be upstream events important for the in vitro activities, because exogenous GSH supplementation blunted DET and DETD-35 effects on A375LM5 IF4g/Luc cells. DET and DETD-35 also induced mitochondrial DNA mutation, superoxide production, mitochondrial bioenergetics dysfunction, and mitochondrial protein deregulation. Most importantly, DET and DETD-35 inhibited lung metastasis of A375LM5 IF4g/Luc in NOD/SCID mice through inhibiting pulmonary vascular permeability and melanoma cell (Mel-A+) proliferation, angiogenesis (VEGF+, CD31+) and EMT ( N -cadherin) in the tumor microenvironment in the lungs. These findings indicate that DET and DETD-35 may be useful in the intervention of lung metastatic BRAF V600E mutant melanoma.

To improve the biological effects of the lead compound 5'-chloro-2,2'-dihydroxychalcone (Cl-DHC), bicyclic aromatic chalcones were designed, synthesized, and evaluated against androgen-independent prostate cancer (PCa) DU145 and PC-3 cell proliferation. Newly synthesized bi-naphthyl derivatives 2 and 3 suppressed the proliferation of these two cell lines and also taxane-resistant prostate cancer cell lines at a submicromolar level. The two compounds were 4-18 times more potent than the parent molecule Cl-DHC. A structure-activity relationship analysis revealed that the orientation of the 10π-electron ring-A naphthalene had a significant effect on the activity. Mode-of-action studies in KB-VIN cells demonstrated that 2 and 3 arrested cells in mitosis at prometaphase and metaphase followed by induction of sub-G1 accumulation. Thus, 2 and 3 have good potential as leads for continued development of treatments for cancers especially for not only androgen-independent PCa but also multidrug-resistant tumors., Competing Interests: The authors declare no competing financial interest., (© 2021 The Authors. Published by American Chemical Society.)

Despite improvements in systemic therapy options for renal cancer, it remains one of the most drug-resistant malignancies. Interestingly, reports have shown that kahweol and cafestol, natural diterpenes extracted from coffee beans, exhibit anti-cancer activity. However, the multiple potential pharmacological actions of both have yet to be fully understood. This study therefore investigated the effects of kahweol acetate and cafestol on human renal cancer ACHN and Caki-1 cells. Accordingly, the combination of kahweol acetate and cafestol administration synergistically inhibited cell proliferation and migration by inducing apoptosis and inhibiting epithelial-mesenchymal transition. Mechanistic dissection revealed that kahweol acetate and cafestol inhibited Akt and ERK phosphorylation. Moreover, kahweol acetate and cafestol downregulated the expression of not only C-C chemokine receptors 2, 5, and 6 but also programmed death-ligand 1, indicating their effects on the tumor microenvironment. Thus, kahweol acetate and cafestol may be novel therapeutic candidates for renal cancer considering that they exert multiple pharmacological effects.

We appreciate Zins and Abraham [1] commenting on our paper studying the role of the CCL20-CCR6 axis on renal cell carcinoma (RCC) cells [2]. As they pointed out, our study has certain limitations. Although M1- and M2-types cannot be separated clearly and a consecutive change of character might exist between them, it has been reported that plural specific markers express on M1- and M2-types. Unfortunately, a definite difference between M1 and M2 macrophages was not confirmed in our study. For more differentiation, multiple stimulations, such as suggested in the comments of Zins and Abraham, might be needed. Hence, we needed to expediently use "M1-like" and "M2-like" to mention specific status of these macrophage-like cells. Meanwhile, CCL20 expression levels of M2-like-THP-1 cells co-cultured with RCC cells were dramatically increased compared with parental THP-1 cells, indicating that certain stimulations within the tumor microenvironment rather than theoretical stimulations make macrophages differentiated; however, further studies are needed to clarify this mechanism using a more appropriate co-culture system mimicking the tumor microenvironment. Immunohistochemistry of CCL20 and M2 markers will help to better understand the role of tissue infiltrating macrophages, even tissue CD68 staining intensity itself was reported to correlate with prognosis of RCC patients [3]. [...]., Competing Interests: The authors declare no conflict of interest.

The first total synthesis of (±)-neocaryachine (1) was achieved using a radical cyclization to produce the dibenzo-9-azabicyclo[3.3.1]nonane pavine skeleton, following a Bischler-Napieralski reaction to construct an intermediate benzylisoquinoline. The resulting racemic mixture was separated by chiral column chromatography to provide pure (+)- and (-)-1.

This study investigated tumor-associated macrophages activity in the microenvironment of renal cell carcinoma. Via a co-culture with macrophage-like cells differentiated from human monocyte cell line THP-1 and U937 cells, the migration ability of ACHN and Caki-1 cells, which are human renal cell carcinoma cell line cells, was significantly increased, as was the epithelial-mesenchymal transition change. A chemokine array identified the CCL20-CCR6 axis as a concentration-dependent signal in ACHN and Caki-1 cell migration. Akt in the ACHN and Caki-1 cells was activated by macrophage-like cells, and the CCL20 neutralizing antibody suppressed migration ability, epithelial-mesenchymal transition, and Akt phosphorylation in the ACHN and Caki-1 cells. Akt inhibitor AZD5363 also decreased the epithelial-mesenchymal transition change and migration ability in the ACHN and Caki-1 cells. In 42 renal cell carcinoma tissues, patients with CCR6 and macrophage infiltration indicated poor prognoses. In the tumor microenvironment of renal cell carcinoma, cancer cells are activated by CCL20 secreted by tumor-associated macrophages through Akt activation, followed by epithelial-mesenchymal transition and an acquired migration ability. Thus, inhibition of the CCL20-CCR6 axis may be a potential therapeutic strategy for renal cell carcinoma.

Seven new butanolides, peltanolides A-G ( 1 - 7 ), and two lignan glucosides, peltasides A ( 8 ) and B ( 9 ), along with eleven known compounds, 10 - 20 , were isolated from a crude CH 3 OH/CH 2 Cl 2 (1:1) extract of the fruit of Hernandia nymphaeifolia (Hernandiaceae). The structures of 1 - 9 were characterized by extensive 1D and 2D NMR spectroscopic and HRMS analysis. The absolute configurations of newly isolated compounds 1 - 9 were determined from data obtained by optical rotation and electronic circular dichroism (ECD) exciton chirality methods. Butanolides and lignan glucosides have not been isolated previously from this genus. Several isolated compounds were evaluated for antiproliferative activity against human tumor cell lines. Lignans 15 and 16 were slightly active against chemosensitive tumor cell lines A549 and MCF-7, respectively. Furthermore, both compounds displayed significant activity (IC 50 = 5 µM) against a P-glycoprotein overexpressing multidrug-resistant tumor cell line (KB-VIN) but were less active against its parent chemosensitive cell line (KB).

The first syntheses of 4- epi-parviflorons A, C, and E (4- epi-1-3) were achieved in 12-13 steps from commercially available (-)-abietic acid (5). All synthesized compounds, including intermediates and derivatives, were evaluated for antiproliferative activity against five human tumor cell lines. A structure-activity relationship study revealed no significant difference between Pf E and 4- epi-Pf E, the importance of two oxygen functional groups at C-11 and C-12 for antiproliferative activity, as well as a combination of carbomethoxy at C-4 and a benzoyl ester with electron-drawing group at C-12 or hydroxymethyl at C-4 and an appropriate oxidation state of ring-B/C for triple-negative breast cancer cell selectivity.

The isolation studies of a crude MeOH/CH 2 Cl 2 (1:1) extract (N005829) of the bark of Laetia corymbulosa yielded 15 new clerodane diterpenes, designated corymbulosins I-W (1-15), as well as four known diterpenes, 16-19. The structures of 1-15 were characterized on the basis of extensive 1D and 2D NMR and HRMS analyses. The absolute configurations of newly isolated compounds 1-15, as well as known 16-19, which were reported previously with only relative configurations, were determined through ECD experiments, X-ray analysis, chemical methods, including Mosher esterification, and comparison of their spectroscopic data. The isolated compounds were evaluated for cytotoxicity against human cancer cell lines. Flow cytometric and immunocytochemical observations of cells treated with cytotoxic clerodanes demonstrated that the chromatin was fragmented and dispersed with formation of apoptotic microtubules.

A novel plant sesquiterpene lactone derivative, DET derivative (DETD)-35, originating from parental deoxyelephantopin (DET) was previously observed to effectively suppress human triple negative breast cancer (TNBC) MDA-MB-231 cell activity and tumor growth in mice. In this study, the mechanisms underlying the activity of DETD-35 were elucidated. DET and DETD-35 induced reactive oxygen species (ROS) which caused structural damage and dysfunction of mitochondria and increased cytosolic calcium level, subsequently evoking exosome release from the cancer cells. Intriguingly, exosomes induced by both compounds had an atypical function. Cancer cell-derived exosomes commonly show metastatic potential, but upon DET/DETD-35 treatment exosomes showed anti-proliferative activity against MDA-MB-231 cells. Quantitative proteome analysis of TNBC cell-secreted exosomes showed that DET and DETD-35 attenuated the expression of proteins related to cell migration, cell adhesion, and angiogenesis. Furthermore, several exosomal proteins participating in biological mechanisms such as oxidative stress and decrease of transmembrane potential of mitochondria were found deregulated by treatment with either compound. Pretreatment with ROS scavenger, N -acetylcysteine, blockaded DET- or DETD-35-induced oxidative stress and calcium dependent exosome release mechanisms, and also reverted DET- or DETD-35-induced reprogramming exosomal protein expression profiles resulting in attenuation of exosomal toxicity against TNBC cell proliferation. In summary, this study shows that a plant-derived sesquiterpene lactone DET and its analog DETD-35 inhibitory TNBC cell activities through oxidative stress-induced cancer cell releasing exosomes in tandem with alteration of exosomal protein composition and functions. The findings of this study suggest that DETD-35 may be suitable for further development into an anti-TNBC drug.

Triple negative breast cancer (TNBC) is a highly metastatic cancer among the breast cancer subgroups. A thorny issue for clinical therapy of TNBC is lack of an efficient targeted therapeutic strategy. We previously created a novel sesquiterpene lactone analog (named DETD-35) derived from plant deoxyelephantopin (DET) which exhibits potent effects against human TNBC MDA-MB-231 tumor growth in a xenograft mouse model. Here we studied the mechanisms of both DET and DETD-35 against MDA-MB-231 cells. DETD-35 (3-fold decreased in IC 50 ) exhibited better anti-TNBC cell activity than DET as observed through induction of reactive oxygen species production (within 2 h treatment) and damage to the ER structures, resulting in ER-derived cytoplasmic vacuolation and ubiquitinated protein accumulation in the treated cells. Intriguingly, the effects of both compounds were blockaded by pretreatment with ROS scavengers, N -acetylcysteine and reduced glutathione, and protein synthesis inhibitor, cycloheximide. Further, knockdown of MEK upstream regulator RAF1 and autophagosomal marker LC3, and co-treatment with JNK or ERK1/2 inhibitor resulted in the most significant attenuation of DETD-35-induced morphological and molecular or biochemical changes in cancer cells, while the inhibitory effect of DET was not influenced by MAPK inhibitor treatment. Therefore, DETD-35 exerted both ER stress-mediated paraptosis and apoptosis, which may explain its superior activity to DET against TNBC cells. Although the chemotherapeutic drug paclitaxel induced vacuole-like structures in MDA-MB-231 cells, no paraptotic cell death features were detected. This study provides a strategy for combating TNBC through sesquiterpene lactone analogs by induction of oxidative and ER stresses that cause paraptosis-like cell death., Competing Interests: CONFLICTS OF INTEREST The authors declare no conflicts of interests.

New clerodane diterpene, 16-hydroxy-pentandralactone (1) and known diterpene acuminolide (2) were isolated from the methanol extract of Vitex cofassus leaves. The chemical structure and the absolute configuration of 1 were determined by MS, NMR and electron circular dichroism (ECD) experiments. The isolated compounds were evaluated for their antiproliferative activities against a panel of human tumor cell lines, including a multidrug-resistant (MDR) cell line. Both compounds showed potent antiproliferative activities against all the tested cell lines with IC 50 values of 5.4-11.4 µM. Their effects on cell viability were also tested using vascular endothelial growth factor (VEGF)-stimulated human umbilical vein endothelial cells (HUVECs). Compound 1 inhibited VEGF-stimulated HUVEC proliferation in a dose-dependent manner. Based on these results, compound 1 could be a candidate for antitumor agent and inhibitor of angiogenesis.

Triple-negative breast cancer (TNBC) is associated with high grade, metastatic phenotype, younger patient age, and poor prognosis. The discovery of an effective anti-TNBC agent has been a challenge in oncology. In this study, fifty-eight ester derivatives (DETDs) with a novel sesquiterpene dilactone skeleton were organically synthesized from a bioactive natural product deoxyelephantopin (DET). Among them, DETD-35 showed potent antiproliferative activities against a panel of breast cancer cell lines including TNBC cell line MDA-MB-231, without inhibiting normal mammary cells M10. DETD-35 exhibited a better effect than parental DET on inhibiting migration, invasion, and motility of MDA-MB-231 cells in a concentration-dependent manner. Comparative study of DETD-35, DET and chemotherapeutic drug paclitaxel (PTX) showed that PTX mainly caused a typical time-dependent G2/M cell-cycle arrest, while DETD-35 or DET treatment induced cell apoptosis. In vivo efficacy of DETD-35 was evaluated using a lung metastatic MDA-MB-231 xenograft mouse model. DETD-35 significantly suppressed metastatic pulmonary foci information along with the expression level of VEGF and COX-2 in SCID mice. DETD-35 also showed a synergistic antitumor effect with PTX in vitro and in vivo. This study suggests that the novel compound DETD-35 may have a potential to be further developed into a therapeutic or adjuvant agent for chemotherapy against metastatic TNBC., Competing Interests: statement The authors declare no competing financial interest., (Copyright © 2016 Federation of European Biochemical Societies. All rights reserved.)

Acquired resistance to vemurafenib develops through reactivation of RAF/MEK/ERK signaling or bypass mechanisms. Recent combination therapies such as a MEK inhibitor combined with vemurafenib show improvement in major clinical end points, but the percentage of patients with adverse toxic events is higher than with vemurafenib monotherapy and most patients ultimately relapse. Therefore, there is an urgent need to develop new antimelanoma drugs and/or adjuvant agents for vemurafenib therapy. In this study, we created a novel semiorganically modified derivative, DETD-35, from deoxyelephantopin (DET), a plant sesquiterpene lactone demonstrated as an anti-inflammatory and anti-mammary tumor agent. Our results show that DETD-35 inhibited proliferation of a panel of melanoma cell lines, including acquired vemurafenib resistance A375 cells (A375-R) established in this study, with superior activities to DET and no cytotoxicity to normal melanocytes. DETD-35 suppressed tumor growth and reduced tumor mass as effectively as vemurafenib in A375 xenograft study. Furthermore, DETD-35 also reduced tumor growth in both acquired (A375-R) and intrinsic (A2058) vemurafenib resistance xenograft models, where vemurafenib showed no antitumor activity. Notably, the combination of DETD-35 and vemurafenib exhibited the most significant effects in both in vitro and in vivo xenograft studies due to synergism of the compound and the drug. Mechanistic studies suggested that DETD-35 overcame acquired vemurafenib resistance at least in part through deregulating MEK-ERK, Akt, and STAT3 signaling pathways and promoting apoptosis of cancer cells. Overall, our results suggest that DETD-35 may be useful as a therapeutic or adjuvant agent against BRAF(V600E) mutant and acquired vemurafenib resistance melanoma. Mol Cancer Ther; 15(6); 1163-76. ©2016 AACR., (©2016 American Association for Cancer Research.)