Antimetastatic Agents Research Articles

Genomic and Molecular Analyses Identify Molecular Subtypes of Pancreatic Cancer Recurrence

Genomic and Molecular Analyses Identify Molecular Subtypes of Pancreatic Cancer Recurrence

Design, Synthesis, and Biological Evaluation of Benzo[cd]indol-2(1H)-ones Derivatives as a Lysosome-Targeted Anti-metastatic Agent.

Lysosomes have become a hot topic in tumor therapy; targeting the lysosome is therefore a promising strategy in cancer therapy. Based on our previous lysosome-targeted bio-imaging agent, homospermine-benzo[cd]indol-2(1H)-one conjugate (HBC), we further developed three novel series of polyamine- benzo[cd]indol-2(1H)-one conjugates. Among them, compound 15f showed potent inhibitory activity in hepatocellular carcinoma migration both in vitro and in vivo. Our study results showed that compound 15f entered the cancer cells via the polyamine transporter localized in the lysosomes and caused autophagy and apoptosis. The mechanism of action revealed that the crosstalk between autophagy and apoptosis induced by 15f was mutually reinforcing patterns. Besides, 15f also targeted lysosomes and exhibited stronger green fluorescence than HBC, which indicated its potential as an imaging agent. To summarize, compound 15f could be used as a valuable dual-functional lead compound for future development against liver-cancer metastasis and lysosome imaging.

Inhibition of A549 Lung Cancer Cell Migration and Invasion by Ent-Caprolactin C via the Suppression of Transforming Growth Factor-β-Induced Epithelial-Mesenchymal Transition.

The epithelial–mesenchymal transition (EMT) of cancer cells is a crucial process in cancer cell metastasis. An Aquimarina sp. MC085 extract was found to inhibit A549 human lung cancer cell invasion, and caprolactin C (1), a new natural product, α-amino-ε-caprolactam linked to 3-methyl butanoic acid, was purified through bioactivity-guided isolation of the extract. Furthermore, its enantiomeric compound, ent-caprolactin C (2), was synthesized. Both 1 and 2 inhibited the invasion and γ-irradiation-induced migration of A549 cells. In transforming growth factor-β (TGF-β)-treated A549 cells, 2 inhibited the phosphorylation of Smad2/3 and suppressed the EMT cell marker proteins (N-cadherin, β-catenin, and vimentin), as well as the related messenger ribonucleic acid expression (N-cadherin, matrix metalloproteinase-9, Snail, and vimentin), while compound 1 did not suppress Smad2/3 phosphorylation and the expression of EMT cell markers. Therefore, compound 2 could be a potential candidate for antimetastatic agent development, because it suppresses TGF-β-induced EMT.

The effect of fascin 1 inhibition on head and neck squamous cell carcinoma cells.

Fascin 1 plays important pro-metastatic roles in head and neck carcinoma (HNSCC) migration, invasion, and metastasis. However, limited advancement in targeting metastasis remains a major obstacle in improving HNSCC patients' survival. Therefore, we assessed the therapeutic potential of fascin 1 targeted inhibition and its potential prognostic value in HNSCC patients. Using in vitro and in vivo approaches, we investigated the effect of compound G2, a novel fascin 1 inhibitor, on HNSCC cells migration, invasion, and metastasis. High-throughput screening (HTS) was used to assess cytotoxic activity of compound G2 alone or combined with irradiation. We also evaluated the prognostic potential of fascin 1 in HNSCC patients. Interestingly, compound G2 reduced carcinoma cells migration and invasion in vitro and inhibited metastasis in vivo. Moreover, HTS revealed a modest cytotoxic activity of the compound G2 on HNSCC cell lines. Irradiation did not synergistically enhance the compound G2-mediated cytotoxic activity. Survival analyses showed that high fascin 1 immunoexpression, at the tumor invasive front, was associated with cancer-specific mortality in the advanced stages of HNSCC. Collectively, our findings suggest that fascin 1 represents a promising anti-metastatic therapeutic target and a useful prognostic marker in patients with HNSCC. Novel anti-metastatic agents could provide a valuable addition to cancer therapy.

Pterostilbene-isothiocyanate inhibits breast cancer metastasis by selectively blocking IKK-β/NEMO interaction in cancer cells

Metastasis, the main cause of breast cancer-associated fatalities, relies on many regular pathways involved in normal cell physiology and metabolism, thus, making it challenging to identify disease-specific therapeutic target(s). Chemically synthesized anti-metastatic agents are preferred for their fast and robust actions. However, these agents have adverse side effects, thus, increasingly favouring the identification of phytocompounds as suitable alternatives. Resveratrol and pterostilbene have long been established as potent anti-cancer agents. Earlier studies from our laboratory documented the anti-cancer activities associated with pterostilbene-isothiocyanate (PTER-ITC), a derivative of pterostilbene. The current study focuses on evaluating the anti-metastatic property of PTER-ITC and the underlying mechanism, by employing in silico, in vitro, and in vivo approaches. The significant anti-metastatic activity of PTER-ITC was observed in vitro against breast cancer metastatic cell line (MDA-MB-231) and in vivo in the 4T1 cell-induced metastatic mice model. Epithelial-mesenchymal transition (EMT), a hallmark of metastasis regulated by the transcription factors, Snail1 and Twist, was found to be reverted in vitro by PTER-ITC treatment. PTER-ITC blocked the activation of NF-κB/p65 and its concomitant nuclear translocation, resulting in the transcriptional repression of its target genes, Snail1 and Twist. PTER-ITC prevented the formation of IKK complex, central to NF-κB activation, by binding to the NEMO-binding domain (NBD) of IKK-β and inhibiting its interaction with NEMO (NF-κB essential modulator). According to our observations, PTER-ITC attenuated NF-κB activation selectively in cancerous cells. In conclusion, this study demonstrated that PTER-ITC is a potent anti-metastatic agent capable of targeting physiologically important pathways in a cancer-specific manner.

Study on the effect and mechanism of NFKBIA on cervical cancer progress in vitro and in vivo.

NFKBIA is frequently encountered. However, its expression and relevance of the proliferation, invasion, and migration in human cervical cancer (CC) remain unclear. The role and novel mechanism of NFKBIA in CC progression were investigated in this study. We analyzed the expression of NFKBIA in CC and adjacent normal tissues and explored the proliferation, migration, and invasion of HeLa cells by treating with either wild-type NFKBIA plasmid or NFKBIA siRNA. Effect of NFKBIA on the epithelial-mesenchymal transition (EMT) and the β-catenin-mediated transcription of target genes were evaluated subsequently. NFKBIA expression was lower in CC tissues than that of adjacent tissues. An obvious dysregulation of NFKBIA overexpression was revealed in CC cell proliferation, invasion, and migration, which differed from the effect of knockdown NFKBIA. NFKBIA overexpression facilitated the expression of both phosphorylated β-catenin and E-cadherin protein. It inhibited the expression of vimentin, TWIST, as well as downstream targets of β-catenin including c-MYC, TCF-4 and MMP14. Conversely, NFKBIA silencing elevated the expression of c-MYC, TCF-4, and MMP14, and promoted the EMT in HeLa cells. Both endogenous and exogenous NFKBIA interacted with β-catenin. Moreover, β-catenin overexpression stemmed effects of NFKBIA on the proliferation, migration, and invasion of HeLa cells. By overexpressing NFKBIA in vivo, the volume and size of tumors were notably decreased, while no obvious alteration was found in mice body weight. By inhibiting β-catenin-mediated transcription, NFKBIA functioning as a tumor suppressor might be introduced as a novel anti-metastatic agent for the treatment of targeted CC.

Impact of Tumor Assessment Frequency on Statistical Power in Randomized Cancer Clinical Trials Evaluating Progression-Free Survival.

Progression-free survival (PFS) is frequently used as a primary endpoint in late-phase clinical trials for anti-metastatic cancer agents. Previous studies have indicated that the frequency of tumor assessment affects the statistical power for PFS because progression dates are inaccurate; however, this finding may be difficult to generalize because of its unrealistic assumptions. Therefore, we re-examined this issue under realistic assumptions and various scenarios that approximate actual clinical trials. Randomized clinical trials comparing two interventions against a solid tumor were simulated under conditions where progressive disease (PD)-dominant PFS or a non-negligible number of deaths (death-competitive PFS) contributed to PFS events, which are conditions that resemble clinical trials of first-line therapy and later-line therapy, respectively. We assessed the impact of tumor assessment frequency on the statistical power. Under the PD-dominant PFS condition, even in extreme scenarios, statistical power loss was only approximately 3%. Under the death-competitive PFS condition, tumor assessment frequency affected the statistical power of PFS if the effect of the treatment on overall survival was lower than that on time to progression. In this case, loss of statistical power was often more than 10% in some realistic scenarios. In trials investigating first-line treatments (PD-dominant PFS), tumor assessment frequency has a negligible impact on statistical power, whereas in trials investigating late-line therapies (death-competitive PFS), the potential impact of tumor assessment frequency on statistical power should be carefully evaluated at the design stage.

Alkaloid derivative ION-31a inhibits breast cancer metastasis and angiogenesis by targeting HSP90α

Breast cancer has become the number one killer of women. In our previous study, an active compound, ION-31a, with potential anti-metastasis activity against breast cancer was identified through the synthesis of ionone alkaloid derivatives. In the present study, we aimed to identify the therapeutic target of ION-31a. We used a fluorescence tag labeled probe, molecular docking simulation, and surface plasmon resonance (SPR) analysis to identify the target of ION-31a.The main target of ION-31a was identified as heat shock protein 90 (HSP90). Thus, ION-31a is a novel HSP90 inhibiter that could suppress the metastasis of breast cancer and angiogenesis significantly in vitro and in vivo. ION-31a acts via inhibiting the HSP90/hypoxia inducible factor 1 alpha (HIF-1α)/vascular endothelial growth factor (VEGF)/VEGF receptor 2 (VEGFR2) pathway and downregulating downstream signal pathways, including protein kinase B (AKT)/mammalian target of rapamycin (mTOR), AKT2/protein kinase C epsilon (PKCζ), extracellular regulated kinase 1/2 (ERK1/2), focal adhesion kinase (FAK), and mitogen-activated protein kinase 14 (p38MAPK) pathways. ION-31a affects multiple effectors implicated in tumor metastasis and has the potential to be developed as an anti-metastatic agent to treat patients with breast cancer.

Retraction Note to: Lupeol inhibits migration and invasion of colorectal cancer cells by suppressing RhoA-ROCK1 signaling pathway.

Metastasis is the main cause of death in colorectal cancer (CRC) patients. However, current treatment options for CRC metastasis are very limited. Lupeol, a triterpene that is widely found in vegetables and fruits, has been reported to possess the cancer-preventive and anti-inflammatory functions. However, the roles of Lupeol in the migration and invasion of colorectal cancer remain unclear. Here, we evaluated the effect of Lupeol treatment on colorectal cancer cell lines, HCT116 and SW620, and delineated its underlying mechanisms. Our results showed that Lupeol induced a dose-dependent inhibition of HCT116 and SW620 cells viability, measured by CCK8 assay. Wound healing and Transwell migration and invasion assays revealed that Lupeol significantly suppressed the migration and invasion of CRC cells. Using laser confocal microscope, we observed that the pseudopods and protrusions of HCT116 and SW620 cells decreased and disrupted after treatment with Lupeol. In addition, the quantitative real-time PCR and Western blotting results showed that Lupeol downregulated the expression of RhoA and RhoC, and their downstream effectors ROCK1, Cofilin, p-MLC, and the associated regulatory protein Cyclin A2. Interestingly, the migration and invasion capacity of CRC cells was reduced after RhoA knockdown. And there were no additional changes in CRC cells with RhoA knockdown to treat with Lupeol. These findings demonstrate that Lupeol can suppress the migration and invasion of colorectal cancer cells by remodeling the actin cytoskeleton via RhoA-ROCK1 pathway inhibition, which may provide an effective anti-metastatic agent for CRC patients.

Abstract 2842: 6-gingerol attenuates metastasis in aged mice model of colorectal cancer through modulation of epithelial-mesenchymal transition mediators genes and e-cadherin upregulation

Abstract Colorectal cancer (CRC) is the third most common cancer in America, and the third cause of cancer related death. Metastasis is the major cause of death in patient with CRC. Many CRC are likely to spread from primary site to the other parts of the body before and after detection of malignant tumor. 6-gingerol, the bioactive component of fresh ginger have been reported to have myriad of biological activities including anti-inflammatory and antioxidant properties. We have previously reported the anti-CRC effect of 6-gingerol. However there is dearth of information on the anti-metastatic effect 6-gingerol in CRC. Thus, the effect of 6-gingerol on epithelial-mesenchymal transition mediators' genes and E-Cadherin repression in aged mice model of CRC was assessed in this study. Following institutional ethical approval. Aged male BALB/c mice (10 months) were divided into four groups of 10 mice each. Mice were fed with AIN-93 diet and allowed access to water ad libitum. Group 1 mice serve as control, group 2 mice received 6-gingerol 10mg/kg/day by oral gavage for 10 weeks. Group 3 mice received a single dose of azoxymethane (AOM) 10mg/kg (iP) and on the seventh day they received three cycles of dextran sulfate sodium (DSS) 2% (W/V) in drinking water ( each cycle is define as one week of DSS followed by two weeks of plain drinking water) Group 4 mice received 6-gingerol 10mg/kg/day by oral gavage in combination with single dose of azoxymethane 10mg/kg (iP) and on the seventh day they received three cycles of dextran sulfate sodium salt 2% (W/V) in drinking water. Mice were humanely sacrificed under anesthesia and colon tissues were processed for RT-PCR and multiplex immunohistochemistry analysis. Mice that received both 6-gingerol and AOM and DSS showed a significant decreased expression of Lymphocyte function-associated antigen-1, N-cadherin, SNAIL 1, ZEB 1, AP4 and HMGA1 with concomitant Upregulation miR-34, miR-15a, miR-218 and miR-302 expression as compared with the AOM and DSS only group. The result obtained from this study showed 6-gingerol inhibited metastasis through modulation of epithelial-mesenchymal transition mediators' genes and E-Cadherin upregulation, and as such 6-gingerol could be a promising anti-metastatic agent in CRC treatment. Citation Format: Babajide Oluwaseun Ajayi, Ayomiposi Adenigba, Anuoluwapo Adeshina. 6-gingerol attenuates metastasis in aged mice model of colorectal cancer through modulation of epithelial-mesenchymal transition mediators genes and e-cadherin upregulation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2842.

Redox-sensitive hyaluronic acid-cholesterol nanovehicles potentiate efficient transmembrane internalization and controlled release for penetrated “full-line” inhibition of pre-metastatic initiation

Metastatic breast cancer is a major cause of cancer-related mortality worldwide. The tumor-specific penetration and triggered drug release for “full-line” inhibition of pre-metastatic initiation are of essential importance in improving mortality rates. Here, a crosslinked, redox-sensitive amphiphilic conjugate (cHLC) was constructed with a combination of features, including hyaluronic acid (HA)-mediated tumor active targeting, lipoic acid (LA) core-crosslinking based bio-stability and reducibility, and lipid raft anchoring-promoted HA-mediated endocytosis through cholesterol (CHO) modification for the penetrated co-delivery of paclitaxel (PTX) and the multi-targeted anti-metastatic agent, silibinin (SB). Resultantly, the nanodrug (cHLC/(PTX + SB)) demonstrated enhanced tumor cytoplasm-selective rapid drug delivery in a 4T1 model both in vitro and in vivo. The released SB efficiently sensitized cells to PTX treatment and inhibited the whole process of pre-metastatic initiation including epithelial-to-mesenchymal transition (EMT), local and blood vessel invasion. The exquisite design of this delivery system provides a deep insight into enhancing focus accessibility of multi-targeted drugs for an efficient inhibition of tumor metastasis.

Dehydrocrenatidine inhibits head and neck cancer cells invasion and migration by modulating JNK1/2 and ERK1/2 pathway and decreases MMP‐2 expression

Head and neck cancer is associated with poor prognosis because of its highly metastatic nature. For the better management of head and neck cancer patients, it is very important to diagnose the cancer at an early stage, as well as to prevent the rapid spread of cancer either through direct invasion or lymphatic metastasis. In present study, the effect of dehydrocrenatidine, which is a beta-carboline alkaloid found in the medicinal plant Picrasma quassioides, on human head and neck cancer metastasis was investigated. The study results revealed the treatment of FaDu, SCC9, and SCC47 cells with 5, 10, and 20 μM of dehydrocrenatidine significantly decreased the motility, migration, and invasion of head and neck cancer cells. Moreover, the dehydrocrenatidine treatment significantly decreased the expression of MMP-2 and phosphorylation of ERK1/2 and JNK1/2. Additional experiments revealed that the cotreatment of dehydrocrenatidine with either ERK1/2 or JNK1/2 inhibitor caused further reduction in cancer cell motility and migration compared to that in dehydrocrenatidine treatment alone. Moreover, similar trend was observed in case of ERK1/2 and JNK1/2 phosphorylation and MMP-2 expression after the cotreatment. Taken together, the mechanism by which dehydrocrenatidine can decrease the phosphorylation of ERK1/2 and JNK1/2, follow decrease the expression of MMP-2 and inhibits head and neck cancer cells invasion and migration. This present study identifies dehydrocrenatidine as a potent antimetastatic agent that can be used clinically to improve head and neck cancer prognosis.

Terrein Inhibits Aggressive Phenotype of A549 Human Lung Cancer Cell through Suppression of HIF-1α

Terrein is a fungal metabolite that has already been reported with anticancer properties. However, the effect on the aggressive phenotype of cancer cells has not been elucidated yet. In the present study, the cytotoxicity of terrein was first determined against lung cancer cells (A549) model and compared with several normal cell lines (Vero, L6, and H9C2 cells). The data demonstrated that terrein had a specific effect on A549 cells relative to normal cells with high selectivity index values. Then, the hypoxic model that recognized to induce aggressive abilities was established in A549 cells by cobalt chloride (CoCl2) stimulation. With this model, terrein could reduce HIF-1α, a marker of hypoxia, and inhibit both migration and invasion of which the effect on invasion is more explicit. Our results demonstrated that terrein has a potential new role as the anti-aggressive phenotype by inhibiting cancer cell migration and invasion through HIF-1α reduction. HIGHLIGHTS Terrein, a secondary bioactive metabolite extracted from Aspergillus terreus, demonstrates anticancer effect on lung cancer cells with less cytotoxic on normal cells CoCl2 treatment was successfully used for creating hypoxic model which resulting in HIF-1a augmentation and aggressive abilities enhancement in lung cancer cells Terrein could reduce HIF-1a expression and invasive ability of lung cancer cells demonstrated the potential role as anti-metastatic agent for lung cancer GRAPHICAL ABSTRACT

Antimetastatic effect of organotin compounds on the model of melanoma B16 in the experiment.

e21564 Background: Melanoma is an extremely malignant tumor. The unfavorable prognosis in the treatment of patients is mainly due to aggressive metastasis of the tumor in various ways: hematogenic, lymphogenic and lymphohematogenic. Metastatic melanoma cells are relatively drug - resistant. Despite some successes in the treatment of melanoma, the search for new antimetastatic substances remains an urgent task of experimental pharmacology and oncology. Organotin compounds were studied by us as promising candidates for antimetastatic agents. Methods: The study was conducted on experimental C57BL/6 mice (n =72, each cohort contained 12 mice) with B16 melanoma (subcutaneous transplantation) to determine the intensity of metastasis in the presence of the cytotoxic organotin compound dimethyltin bis (3,5-di-tert-butyl-4-hydroxyphenylthiolate) [1-3] (Me3). All manipulations were carried out in accordance with the European Convention for the Protection of Vertebrates Used for Experimental and Other Scientific Purposes (ETS 123). Female mice (8 weeks of age, weighing 21-22 g) were administered intraperitoneal 1% aqueous gelatin solution of organotin Me3 daily for 5 days. The total doses in the first series of the experiment were 150, 250, 375 mg/kg (I, II, III cohorts and IV control group), which allowed us to choose the most effective dose of Me3. After that, in the second series of experiments, the metastasis inhibition index was evaluated in group V (total dose 375 mg/kg) and control group VI. The animals were euthanized on the 18th day after the tumor was inoculated. Results: It was shown that when administered intraperitoneal to mice, Me3 did not inhibit the growth of B16 melanoma in any of the groups. The results showed that the average life expectancy of animals in the experimental group III with the introduction of Me3 at a dose of 375 mg/kg significantly increased and amounted to 30.1±2.5 days, in control mice of group IV-21.8±2.6 days. In the second series of the experiment, after 18 days, the index of metastasis inhibition was almost twice lower (54%) in group V than in the control group (VI). Conclusions: It is concluded that the overall result of this study clearly demonstrates that the organotin compound dimethyltin bis (3,5-di-tert-butyl-4-hydroxyphenylthiolate) (Me3) is an effective antimetastatic agent in transplanted experimental mouse melanoma B16 at a total dose of 375 mg/kg.

Organotin compounds as effective antimetastatic substances in the treatment of epidermoid lung carcinoma Lewis (LLC) in an experiment.

e15054 Background: Lung cancer occupies one of the first places in the structure of oncological diseases in the world. Reducing the life expectancy of patients, as a rule, occurs as a result of metastatic complications, so the search for new antimetastatic agents is an urgent task for experimental pharmacology and oncology. The aim of our study is to assess the severity of metastatic lesion in the Lewis lung epidermoid carcinoma (LLC) model in the presence of an organotin compound. Methods: The study was conducted on experimental C57BL/6 mice (n = 24, each group contained 12 mice) with LLC (subcutaneous transplantation) in the presence of the cytotoxic organotin compound 2,6-bis (1,1-dimethylethyl) - 4 - [(triphenylstannyl)thio]phenol (Me5). All manipulations were carried out in accordance with the European Convention for the Protection of Vertebrates Used for Experimental and Other Scientific Purposes (ETS 123). Female mice (8 weeks of age, weighing 21-22 g) were intraperitoneally injected with a 1% aqueous gelatin solution of organotin Me5 daily for 5 days. The most effective total dose of Me5 was 250 mg / kg. The animals of the control group received saline solution in similar modes and volumes. In the experimental and control groups, the degree of metastatic lesion was assessed on the 21-day post-grafting period according to the scale proposed by D. Tarin and J. E. Price, which allows us to differentiate the severity of the lesion depending on the number of metastases and their size. The experiment describes three degrees of lesion: LCP-1 (metastases less than 10 pcs. with a diameter not exceeding 1 mm); LCP-2 (metastases from 10 to 30 pieces, some of them larger than 1 mm) and HCP-3 (metastases larger than 30 pieces of different sizes, but no drain). The pathohistological structure was studied by the light-optical method with hematoxylin and eosin staining. Results: When administered intraperitoneal to mice, Me5 did not inhibit the growth of the primary tumor site in the experimental group, but significantly reduced the severity of metastatic lesions in the lungs. In the control group, 75 % of mice with LLC had LCP - 2 (low colonization potential) and in 25% of HCP-3 (high colonization potential) metastatic lesions, in the experimental group only mild lesions were noted in all animals: 58% of mice had LCP – 1, 42% - LCP-2. Conclusions: It is concluded that the overall result of this study clearly demonstrates that the organotin compound 2,6-bis (1,1-dimethylethyl) - 4 - [(triphenylstannyl)thio] phenol (Me5) is an effective antimetastatic agent in the Lewis lung epidermoid carcinoma (LLC) model at a total dose of 250 mg/kg.

New tropolone derivative to inhibit cell motility in colorectal cancer cells.

e15043 Background: Tropolones are small, naturally occurring organic compounds that have anti-cancer effects in a variety of cancer cell lines. Among proposed mechanisms of tropolone derivatives anti-cancer activity are caspase activation, matrix metalloproteinases and histone deacetylases inhibition and other actions. Since matrix metalloproteinases are the major proteins that contribute to tumor cell tissue invasion and migration their blockers are extensively studied as prospective anti metastatic agents. We assumed that tropolones may also have potential as metastases prevention drugs. The aim of the study was to investigate the influence of new tropolone derivative 2-(6,8-dimethyl-5-nitro-4-chloroquinolin-2-yl)-5,6,7-trichloro-1,3-tropolone on the cell migration capacity in colorectal cancer cells. Methods: Cell migration in permanent colorectal cancer cell lines HT29, Caco2 and HCT116 was studied using the standard wound healing assay with automated image acquisition and analysis on Lionheart FX (BioTek) cell imager. Cell cultures were maintained in DMEM medium with L-glutamine (1 μM) (Gibco) and 10% FBS (Gibco) at 37C0 and 5.0% CO2. The day before assay establishment cells were seeded at 250 000 cells per well on 24-well plates. After attachment of cells, a vertical wound in cell layer was made manually in each well, and then medium with studied tropolone derivative (5 μM) was added. Plates with cells were continuously incubated and photographed in cell imager at 37C0 and 5.0% CO2. The extent of cells migration was measured as the percent of wound area decrease after 48 hours of incubation in relation to starting time point. Data are given as: Mean ± 95% confidence interval. Results: The new tropolone derivative under study exhibited pronounced anti migratory activity in all studied colorectal cancer cell cultures. The most prominent effect was observed in HCT116 cell line: after 48 hours of incubation relative wound area decrease was 48.2%±5.7% in control and 7.2%±3.15% in experimental groups. In Caco2 cell line cell migration inhibition was the least with 65%± 6.9% relative wound area decrease in control and 51.5%± 7.7% in experimental groups. The moderate effect was observed in HT29 cell line (measured parameter was 63.6%±7.6% and 36.9%±11.6% in control and experimental groups accordingly). The obtained difference between control and experimental groups was significant in all tested cell cultures at 0.05 level (df = 30). Conclusions: Results of the present study prove tropolone derivative to be prospective candidates for anti-metastatic drug development. Further investigations are needed to reveal the exact mechanisms of tropolones anti-migratory activity.

Selective anticancer activities of ruthenium(II)-tetrazole complexes and their mechanistic insights

Ruthenium-based metallotherapeutics is an interesting alternative for platinum complexes acting as anticancer agents after the entry of KP1019, NAMI-A, and TLD1339 in clinical trials. Herein, we have synthesized three new arene ruthenium(II)-tetrazole complexes viz. [Ru2(η6-p-cymene)2(2-pytz)2Cl2] (1), [Ru2(η6-p-cymene)2(3-pytz)Cl3] (2), [Ru2(η6-p-cymene)2(4-pytz)Cl3] (3) [2-pytzH = 2-pyridyl tetrazole; 3-pytzH = 3-pyridyl tetrazole; 4-pytzH = 4-pyridyl tetrazole] which have been characterized by different analytical techniques. To aid the understanding of the complex formation, reactions of the arene ruthenium(II) dimer with tetrazoles were investigated using the first principles-based Density Functional Theory (DFT) B3LYP method. Electronic structures, equilibrium geometries of the reactants and products with the first-order saddle points, reactions mechanism, the changes of enthalpy (∆H) and free energy (∆G), chemical stability, and reaction barriers of the complexes were computed using the B3LYP DFT approach. The in vitro cytotoxicity of these complexes was investigated by MTT assay on different cancer cell lines which reveal complex 2 as the most significant cytotoxic agent toward the HeLa cell line. The complexes have also shown a strong binding affinity towards CT-DNA and albumin proteins (HSA and BSA) as analyzed through spectroscopic techniques. Investigation of the mechanism of cell death by complex 2 was further performed by various staining techniques, flow cytometry, and gene expression analysis by RT-PCR. Inhibition of cell migration study has been also revealed the possibility of complex 2 to act as a prospective anti-metastatic agent.

A naphthalimide-polyamine conjugate preferentially accumulates in hepatic carcinoma metastases as a lysosome-targeted antimetastatic agent.

Disseminated tumors lead to approximately 90% of cancer-associated deaths especially for hepatocellular carcinoma (HCC), indicating the imperative need of antimetastatic drugs and the ineffectiveness of current therapies. Recently polyamine derivatives have been identified as a promising prospect in dealing with metastatic tumors. Herein, a novel class of naphthalimide-polyamine conjugates 8a-8d, 13a-13c, 17 and 21 were synthesized and the mechanism was further determined. The polyamine conjugate 13b displayed remarkably elevated anti-tumor and anti-metastatic effects (76.01% and 75.02%) than the positive control amonafide (46.91% and 55.77%) at 5mg/kg invivo. The underlying molecular mechanism indicated that in addition to induce DNA damage by up-regulating p53 and γH2AX, 13b also targeted lysosome to modulate polyamine metabolism and function in a totally different way from that of amonafide. Furthermore, the HMGB1/p62/LC3II/LC3I and p53/SSAT/β-catenin pathways were mainly involved in the inhibition of 13b-induced HCC metastasis by targeting polyamine transporters (PTs) overexpressed in HCC. At last, 13b down-regulated the concentrations of Put, Spd and Spm by modulating polyamine metabolism key enzymes SSAT and PAO, which favored the suppression of fast growing tumor cells. Taken together, our study implies a promising strategy for naphthalimide conjugates to treat terminal cancer of HCC by targeting autophagy and tumor microenvironment with reduced toxicities and notable activities.

Identification of trans-AT polyketide clusters in two marine bacteria reveals cryptic similarities between distinct symbiosis factors.

Glutarimide-containing polyketides are known as potent antitumoral and antimetastatic agents. The associated gene clusters have only been identified in a few Streptomyces producers and Burkholderia gladioli symbiont. The new glutarimide-family polyketides, denominated sesbanimides D, E and F along with the previously known sesbanimide A and C, were isolated from two marine alphaproteobacteria Stappia indica PHM037 and Labrenzia aggregata PHM038. Structures of the isolated compounds were elucidated based on 1D and 2D homo and heteronuclear NMR analyses and ESI-MS spectrometry. All compounds exhibited strong antitumor activity in lung, breast and colorectal cancer cell lines. Subsequent whole genome sequencing and genome mining revealed the presence of the trans-AT PKS gene cluster responsible for the sesbanimide biosynthesis, described as sbn cluster. Strikingly, the modular architecture of downstream mixed type PKS/NRPS, SbnQ, revealed high similarity to PedH in pederin and Lab13 in labrenzin gene clusters, although those clusters are responsible for the production of structurally completely different molecules. The unexpected presence of SbnQ homologues in unrelated polyketide gene clusters across phylogenetically distant bacteria, raises intriguing questions about the evolutionary relationship between glutarimide-like and pederin-like pathways, as well as the functionality of their synthetic products.

Discovery of β-carboline-(phenylsulfonyl)furoxan hybrids as potential anti-breast cancer agents

The cytotoxicity properties of the β-carboline alkaloids have been broadly investigated. However, the potential application of β-carbolines was hindered due to the moderate activity in cancer. In the present study, thirty β-carboline-(phenylsulfonyl)furoxan hybrids (11a–j, 12a–j and 13a–j) were designed and synthesized through esterification and amidation reaction strategy, and their inhibitory activities against the human breast cancer cell lines MCF-7 and MDA-MB-231 were evaluated by CCK-8 assay. Biological evaluation presented that the most promising amide derivative 13h, substituted with p-methoxyphenyl group at position 1, generated high concentration of NO and evidently depressed the MCF-7 (IC50 = 0.89 μM) and MDA-MB-231 (IC50 = 0.62 μM) cells proliferation. Particularly, the wound healing and transwell assays demonstrated that 13h significantly inhibited the migration and invasion of MDA-MB-231cells. Furthermore, the preliminary mechanisms studies indicated that 13h induced G2/M phase arrest and apoptosis possibly causing by ROS accumulation and ROS-mediated DNA damage. Based on these considerations, 13h may be a promising antimetastatic agent for breast cancer, which is noteworthy for further exploration.