Proteomic characterization and cytotoxic potential of proteins from Cuscuta (Cuscuta epithymum (L.) crude herbal product against MCF-7 human breast cancer cell line.

BACKGROUND: The burden of breast cancer, the second leading cause of death worldwide, is increasing at an alarming rate. Cuscuta, used in traditional medicine for different ailments, including cancer, is known for containing phytochemicals that exhibit anticancer activity; however, the bioactivities of proteins from this plant remain unexplored. This study aimed to screen the cytotoxic potential of proteins from the crude herbal product of Cuscuta epithymum(L.) (CE) harvested from the host plants Alhagi maurorum and Medicago sativa. METHODS: The proteins from CE were extracted using a salting-out method, followed by fractionation with a gel filtration chromatography column. Gel-free shotgun proteomics was subsequently performed for protein characterization. The viability assay using MTT was applied to deduce the cytotoxic potential of proteins against MCF-7 breast cancer cells, with further exploration of the effect of treatment on the expression of the apoptotic mediator BCL2-associated X protein (BAX) and B-cell lymphoma protein 2 (BCL-2) proteins, using western blotting to strengthen the findings from the in vitro viability assay. RESULTS: The crude proteins (CP) of CE were separated into four protein peaks (P1, P2, P3, and P4) by gel filtration chromatography. The evaluation of potency showed a dose-dependent decline in the MCF-7 cell line after CP, P1, P2, and P3 treatment with the respective IC50 values of 33.8, 43.1, 34.5, and 28.6 µg/ml. The percent viability of the cells decreased significantly upon treatment with 50 µg/ml CP, P1, P2, and P3 (P < 0.001). Western-blot analysis revealed upregulation of proapoptotic protein BAX in the cells treated with CP, P3 (P < 0.01), and P2 (P < 0.05); however, the antiapoptotic protein, BCL-2 was downregulated in the cells treated with CP and P3 (P < 0.01), but no significant change was detected in P2 treated cells. The observed cytotoxic effects of proteins in the CP, P1, P2, and P3 from the in vitro viability assay and western blot depicted the bioactivity potential of CE proteins. The database search revealed the identities of functionally important proteins, including nonspecific lipid transfer protein, superoxide dismutase, carboxypeptidase, RNase H domain containing protein, and polyribonucleotide nucleotidyltransferase, which have been previously reported from other plants to exhibit anticancer activity. CONCLUSION: This study indicated the cytotoxic activity of Cuscuta proteins against breast cancer MCF-7 cells and will be utilized for future investigations on the mechanistic effect of active proteins. The survey of CE proteins provided substantial data to encourage further exploration of biological activities exhibited by proteins in Cuscuta.

Regulation of Oxidative Stress and Apoptosis in Streptozotocin-Induced Diabetic Rats by Egyptian Sidr Honey.

Diabetes mellitus is a global health issue characterized by hyperglycemia which leads over time to severe damage to numerous tissues. The present study aimed to estimate the effect of Egyptian Sidr honey against streptozotocin-induced diabetes in rats. Diabetic rats were treated with Sidr honey daily for 4 consecutive weeks. The biochemical profile of blood samples was measured. Furthermore, the activity of antioxidant enzymes, nitric oxide (NO), and malonaldehyde (MDA) were examined in liver and pancreas tissues. Moreover, the expression of Bax, Caspase-3, and Bcl2 proteins were measured. Results revealed that the capability of Sidr honey to decline the elevated blood glucose and fructosamine levels compared to diabetic rats. Also, the honey decreased the levels of NO and MDA. Furthermore, it regulated the antioxidant enzymes activity. Moreover, it reduced the expression levels of Caspase-3 and Bax while increased the Bcl2 level. In conclusion, Sidr honey can regulate hyperglycemia, oxidative stress, apoptosis, and antioxidant enzymes in STZ-induced diabetic rats.

Apilarnil ameliorates Bisphenol A-induced testicular toxicity in adult male rats via improving antioxidant potency and PCNA expression.

Apilarnil, a bee-derived product originating from drone larvae, offers a range of advantageous properties for both humans and animals. It functions as an antioxidant, provides neuroprotection, boosts fertility, and has antiviral capabilities. Additionally, it is a provider of androgenic hormones. These beneficial functions are supported by its chemical composition, which comprises mineral salts, vitamins, carbs, lipids, hormones, and amino acids. The current study aimed to evaluate the ameliorative effect of apilarnil against Bisphenol A (BPA)-induced testicular toxicity in male adult rats. Forty-eight Wistar albino rats were randomly classified into six groups. The first, second, and third received olive oil, BPA at a dose of 50 mg/kg body weight (bwt), and apilarnil at a dose of 0.6 g/kg bwt, respectively. The fourth, fifth, and sixth groups received apilarnil with, before, or after BPA administration, respectively. Phytochemical analysis using included linear ion trap-ultra-performance liquid chromatography-tandem mass spectrometry (LTQ-UPLC-MS/MS) and global natural products social molecular networking (GNPS) revealed the presence of lysine, 10-hydroxy-(E)-2-dodecenoic acid, apigenin7-glucoside, testosterone, progesterone, and campesterol. BPA administration decreased serum level of follicle stimulating hormone (FSH), luteinizing hormone (LH), testosterone, glutathione (GSH) concentration, total sperm count, motility, and vitality. Additionally, BPA increased sperm abnormalities, malondialdehyde concentration (MDA), and decreased proliferating cell nuclear antigen (PCNA) expression. The treatment with apilarnil ameliorated BPA reproductive toxicity in rats which was indicated by increased serum testosterone levels, normalized serum levels of FSH and LH, and concentration of MDA and GSH activity. Moreover, apilarnil improved sperm count, motility, morphology, and PCNA expression. Apilarnil was found to enhance reproductive hormones, MDA levels, antioxidant activity, and PCNA expression.

Cryptolepine Analog exhibits Antitumor Activity against Ehrlich Ascites Carcinoma Cells in Mice via Targeting Cell Growth, Oxidative Stress, and PTEN/Akt/mTOR Signaling Pathway.

BACKGROUND: The efficacy of chemotherapy continues to be limited due to associated toxicity and chemoresistance. Thus, synthesizing and investigating novel agents for cancer treatment that could potentially eliminate such limitations is imperative. OBJECTIVE: The current study aims to explore the anticancer potency of cryptolepine (CPE) analog on Ehrlich ascites carcinoma cells (EACs) in mice. METHODS: The effect of a CPE analog on EAC cell viability and ascites volume, as well as malonaldehyde, total antioxidant capacity, and catalase, were estimated. The concentration of caspase-8 and mTOR in EACs was also measured, and the expression levels of PTEN and Akt were determined. RESULTS: Results revealed that CPE analog exerts a cytotoxic effect on EAC cell viability and reduces the ascites volume. Moreover, this analog induces oxidative stress in EACs by increasing the level of malonaldehyde and decreasing the level of total antioxidant capacity and catalase activity. It also induces apoptosis by elevating the concentration of caspase-8 in EACs. Furthermore, it decreases the concentration of mTOR in EACs. Moreover, it upregulates the expression of PTEN and downregulates the expression of Akt in EACs. CONCLUSION: Our findings showed the anticancer activity of CPE analog against EACs in mice mediated by regulation of the PTEN/Akt/mTOR signaling pathway.

The structural characterization and bioactivity assessment of nonspecific lipid transfer protein 1 (nsLTP1) from caraway (Carum carvi) seeds.

BACKGROUND: Carum carvi (caraway) of the Apiaceae family has been used in many cultures as a cooking spice and part of the folk medicine. Previous reports primarily focus on the medicinal properties of caraway seed essential oil and the whole seeds extract. However, no effort has been made to study caraway proteins and their potential pharmacological properties, including nonspecific lipid transfer protein (nsLTP), necessitating further research. The current study aimed to characterize nonspecific lipid transfer protein 1 (nsLTP1) from caraway seed, determine its three-dimensional structure, and analyze protein-ligand complex interactions through docking studies. We also evaluated nsLTP1 in vitro cytotoxic effect and antioxidant capacity. Additionally, nsLTP1 thermal- and pH- stability were investigated. METHODS: Caraway nsLTP1 was purified using two-dimensional chromatography. The complete amino acid sequence of nsLTP1 was achieved by intact protein sequence for the first 20 residues and the overlapping digested peptides. The three-dimensional structure was predicted using MODELLER. Autodock Vina software was employed for docking fatty acids against caraway nsLTP1. Assessment of nsLTP1 cytotoxic activity was achieved by MTS assay, and the Trolox equivalent antioxidant capacity (TAC) was determined. Thermal and pH stability of the nsLTP1 was examined by circular dichroism (CD) spectroscopy. RESULTS: Caraway nsLTP1 is composed of 91 residues and weighs 9652 Da. The three-dimensional structure of caraway nsLTP1 sequence was constructed based on searching known structures in the PDB. We chose nsLTP of Solanum melongena (PDB ID: 5TVI) as the modeling template with the highest identity among all other homologous proteins. Docking linolenic acid with caraway protein showed a maximum binding score of -3.6 kcal/mol. A preliminary screening of caraway nsLTP1 suppressed the proliferation of human breast cancer cell lines MDA-MB-231 and MCF-7 in a dose­dependent manner with an IC50 value of 52.93 and 44.76 µM, respectively. Also, nsLTP1 (41.4 µM) showed TAC up to 750.4 µM Trolox equivalent. Assessment of nsLTP1 demonstrated high thermal/pH stability. CONCLUSION: To the best of our knowledge, this is the first study carried out on nsLTP1 from caraway seeds. We hereby report the sequence of nsLTP1 from caraway seeds and its possible interaction with respective fatty acids using in silico approach. Our data indicated that the protein had anticancer and antioxidant activities and was thermally stable.

Design, Synthesis, and Antiproliferative Activity of Benzopyran-4-One-Isoxazole Hybrid Compounds.

The biological significance of benzopyran-4-ones as cytotoxic agents against multi-drug resistant cancer cell lines and isoxazoles as anti-inflammatory agents in cellular assays prompted us to design and synthesize their hybrid compounds and explore their antiproliferative activity against a panel of six cancer cell lines and two normal cell lines. Compounds 5a-d displayed significant antiproliferative activities against all the cancer cell lines tested, and IC50 values were in the range of 5.2-22.2 µM against MDA-MB-231 cancer cells, while they were minimally cytotoxic to the HEK-293 and LLC-PK1 normal cell lines. The IC50 values of 5a-d against normal HEK-293 cells were in the range of 102.4-293.2 µM. Compound 5a was screened for kinase inhibitory activity, proteolytic human serum stability, and apoptotic activity. The compound was found inactive towards different kinases, while it completely degraded after 2 h of incubation with human serum. At 5 µM concentration, it induced apoptosis in MDA-MB-231 by 50.8%. Overall, these findings suggest that new benzopyran-4-one-isoxazole hybrid compounds, particularly 5a-d, are selective anticancer agents, potentially safe for human cells, and could be synthesized at low cost. Additionally, Compound 5a exhibits potential anticancer activity mediated via inhibition of cancer cell proliferation and induction of apoptosis.

Chemistry and the Potential Antiviral, Anticancer, and Anti-Inflammatory Activities of Cardiotonic Steroids Derived from Toads.

Cardiotonic steroids (CTS) were first documented by ancient Egyptians more than 3000 years ago. Cardiotonic steroids are a group of steroid hormones that circulate in the blood of amphibians and toads and can also be extracted from natural products such as plants, herbs, and marines. It is well known that cardiotonic steroids reveal effects against congestive heart failure and atrial fibrillation; therefore, the term "cardiotonic" has been coined. Cardiotonic steroids are divided into two distinct groups: cardenolides (plant-derived) and bufadienolides (mainly of animal origin). Cardenolides have an unsaturated five-membered lactone ring attached to the steroid nucleus at position 17; bufadienolides have a doubly unsaturated six-membered lactone ring. Cancer is a leading cause of mortality in humans all over the world. In 2040, the global cancer load is expected to be 28.4 million cases, which would be a 47% increase from 2020. Moreover, viruses and inflammations also have a very nebative impact on human health and lead to mortality. In the current review, we focus on the chemistry, antiviral and anti-cancer activities of cardiotonic steroids from the naturally derived (toads) venom to combat these chronic devastating health problems. The databases of different research engines (Google Scholar, PubMed, Science Direct, and Sci-Finder) were screened using different combinations of the following terms: "cardiotonic steroids", "anti-inflammatory", "antiviral", "anticancer", "toad venom", "bufadienolides", and "poison chemical composition". Various cardiotonic steroids were isolated from diverse toad species and exhibited superior anti-inflammatory, anticancer, and antiviral activities in in vivo and in vitro models such as marinobufagenin, gammabufotalin, resibufogenin, and bufalin. These steroids are especially difficult to identify. However, several compounds and their bioactivities were identified by using different molecular and biotechnological techniques. Biotechnology is a new tool to fully or partially generate upscaled quantities of natural products, which are otherwise only available at trace amounts in organisms.

New phthalimide analog ameliorates CCl4 induced hepatic injury in mice via reducing ROS formation, inflammation, and apoptosis.

The present study aimed, for the first time, to examine the biochemical effects of new phthalimide analog, 2-[2-(2-Bromo-1-ethyl-1H-indol-3-yl) ethyl]-1H-isoindole-1,3(2H)-dione, compared to thalidomide drug against liver injury induced in mice. Carbon tetrachloride was intraperitoneal injected in mice for 6 consecutive weeks at a dose of 0.4 mL/kg twice a week for liver injury induction. Histopathological examination, levels of malondialdehyde, nitric oxide, and antioxidant enzymes were determined. Additionally, the protein levels of vascular endothelial growth factor, proliferating cell nuclear protein, tumor necrosis factor-alfa, nuclear factor kappa B-p65, B-cell lymphoma-2, and cysteine-aspartic acid protease-3 were determined. Results revealed that the treatment with phthalimide analog improved the detected liver damage and presented an obvious antioxidant activity through decreasing malondialdehyde and nitric oxide levels accompanied by increasing the levels of the antioxidant enzymes. Furthermore, the analog exhibited an effective inhibitory activity towards the studied protein expressions in liver tissues. Moreover, the B-cell lymphoma-2 protein level was increased while the cysteine-aspartic acid protease-3 level was suppressed after the treatment with phthalimide analog. Together, these results propose that phthalimide analog can ameliorate carbon tetrachloride-induced liver injury in mice through its potent inhibition mediating effect in oxidative stress, inflammation, and apoptosis mechanisms.

Protective Effects of Flavone from Tamarix aphylla against CCl4-Induced Liver Injury in Mice Mediated by Suppression of Oxidative Stress, Apoptosis and Angiogenesis.

The current study aimed to investigate, for the first time, the beneficial effects of 3,5-dihydroxy-4',7-dimethoxyflavone isolated from Tamarix aphylla L. against liver injury in mice. Liver injury was induced by intraperitoneal (i.p.) injection of carbon tetrachloride (CCl4) at a dose of 0.4 mL/kg mixed in olive oil at ratio (1:4) twice a week for 6 consecutive weeks. The administration of CCl4 caused significant histopathological changes in liver tissues while the pre-treatment with the flavone at dose of 10 and 25 mg/kg ameliorated the observed liver damages. Also, it markedly reduced hepatic malondialdehyde (MDA) level as well as increased the activities of liver superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (Gpx) compared with their recorded levels in CCl4 model group. Moreover, the immunohistochemical analysis demonstrated the enhancement in the protein level of B-cell lymphoma-2 (Bcl-2) while the protein levels of cysteine-aspartic acid protease-3 (caspase-3), Bcl-2-associated x protein (Bax), transforming growth factor-ß1 (TGF-ß1) and CD31 were suppressed following the flavone treatement. These results suggest that the flavone can inhibit liver injury induced in mice owning to its impact on the oxidation, apoptotic and angiogenesis mechanisms. Further pharmacological investigations are essential to determine the effectiveness of the flavone in human.

Synthesis, Characterization, and In Vivo Anti-Cancer Activity of New Metal Complexes Derived from Isatin-N(4)antipyrinethiosemicarbazone Ligand Against Ehrlich Ascites Carcinoma Cells.

The current study aimed to synthesize new metal coordination complexes with potential biomedical applications. Metal complexes were prepared via the reaction of isatin-N(4)anti- pyrinethiosemicarbazone ligand 1 with Cu(II), Ni(II), Co(II), Zn(II), and Fe(III) ions. The obtained metal complexes 2-12 were characterized using elemental, spectral (1H-NMR, EPR, Mass, IR, UV-Vis) and thermal (TGA) techniques, as well as magnetic moment and molar conductance measurements. In addition, their geometries were studied using EPR and UV-Vis spectroscopy. To evaluate the in vivo anti-cancer activities of these complexes, the ligand 1 and its metal complexes 2, 7 and 9 were tested against solid tumors. The solid tumors were induced by subcutaneous (SC) injection of Ehrlich ascites carcinoma (EAC) cells in mice. The impact of the selected complexes on the reduction of tumor volume was determined. Also, the expression levels of vascular endothelial growth factor (VEGF) and cysteine aspartyl-specific protease-7 (caspase-7) in tumor and liver tissues of mice bearing EAC tumor were determined. Moreover, their effects on alanine transaminase (ALT), aspartate transaminase (AST), albumin, and glucose levels were measured. The results revealed that the tested compounds, especially complex 9, reduced tumor volume, inhibited the expression of VEGF, and induced the expression of caspase-7. Additionally, they restored the levels of ALT, AST, albumin, and glucose close to their normal levels. Taken together, our newly synthesized metal complexes are promising anti-cancer agents against solid tumors induced by EAC cells as supported by the inhibition of VEGF and induction of caspase-7.

Cancer stem cell induction from mouse embryonic stem cells.

Although cancers are often removed by surgery and treated by chemotherapy and/or radiation therapies, they often reoccur following treatment due to the presence of resistant residual cells such as cancer stem cells (CSCs). CSCs are characterized by their self-renewal, pluripotency, and tumorigenicity properties, and are promising therapeutic targets for the complete therapy of cancers; however, the number of CSCs in cancer tissue is typically too small to investigate fully. We have previously reported that CSCs could be established from induced pluripotent stem cells (iPSCs) using a conditioned medium during cancer cell culture. In the present study, mouse embryonic stem cells (mESCs) were observed to be converted to CSCs (mES-CSCs). This demonstrated that CSC induction does not exclusively occur following gene editing in somatic cells, and that conditioned medium from cancer cells may contain factors that can induce CSCs. Therefore, not only iPSCs but also mESCs, were demonstrated to be able to produce CSCs as one of the potentials of pluripotency of stem cells, suggesting that the conversion to CSCs is not specific to iPSCs. The resultant mES-CSCs would be also useful to generate tissue specific cancers and these naturally occurring cancers can contribute to drug screenings, but also undergo further investigation in order to reveal cancer mechanisms.

Alpinia zerumbet (Pers.): Food and Medicinal Plant with Potential In Vitro and In Vivo Anti-Cancer Activities.

BACKGROUND/AIM: Plants play an important role in anti-cancer drug discovery, therefore, the current study aimed to evaluate the biological activity of Alpinia zerumbet (A. zerumbet) flowers. METHODS: The phytochemical and biological criteria of A. zerumbet were in vitro investigated as well as in mouse xenograft model. RESULTS: A. zerumbet extracts, specially CH2Cl2 and MeOH extracts, exhibited the highest potent anti-tumor activity against Ehrlich ascites carcinoma (EAC) cells. The most active CH2Cl2 extract was subjected to bioassay-guided fractionation leading to isolatation of the naturally occurring 5,6-dehydrokawain (DK) which was characterized by IR, MS, 1H-NMR and 13C-NMR. A. zerumbet extracts, specially MeOH and CH2Cl2 extracts, exhibited significant inhibitory activity towards tumor volume (TV). Furthermore, A. zerumbet extracts declined the high level of malonaldehyde (MDA) as well as elevated the levels of superoxide dismutase (SOD) and catalase (CAT) in liver tissue homogenate. Moreover, DK showed anti-proliferative action on different human cancer cell lines. The recorded IC50 values against breast carcinoma (MCF-7), liver carcinoma (Hep-G2) and larynx carcinoma cells (HEP-2) were 3.08, 6.8, and 8.7 µg/mL, respectively. CONCLUSION: Taken together, these findings open the door for further investigations in order to explore the potential medicinal properties of A. zerumbet.

Melittin Exerts Beneficial Effects on Paraquat-Induced Lung Injuries In Mice by Modifying Oxidative Stress and Apoptosis.

Melittin (MEL) is a 26-amino acid peptide with numerous biological activities. Paraquat (PQ) is one of the most widely used herbicides, although it is extremely toxic to humans. To date, PQ poisoning has no effective treatment, and therefore the current study aimed to assess for the first time the possible effects of MEL on PQ-induced lung injuries in mice. Mice received a single intraperitoneal (IP) injection of PQ (30 mg/kg), followed by IP treatment with MEL (0.1 and 0.5 mg/kg) twice per week for four consecutive weeks. Histological alterations, oxidative stress, and apoptosis in the lungs were studied. Hematoxylin and eosin (H&E) staining indicated that MEL markedly reduced lung injuries induced by PQ. Furthermore, treatment with MEL increased superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activity, and decreased malonaldehyde (MDA) and nitric oxide (NO) levels in lung tissue homogenates. Moreover, immunohistochemical staining showed that B-cell lymphoma-2 (Bcl-2) and survivin expressions were upregulated after MEL treatment, while Ki-67 expression was downregulated. The high dose of MEL was more effective than the low dose in all experiments. In summary, MEL efficiently reduced PQ-induced lung injuries in mice. Specific pharmacological examinations are required to determine the effectiveness of MEL in cases of human PQ poisoning.

Design, synthesis, biological evaluations, molecular docking, and in vivo studies of novel phthalimide analogs.

A series of novel phthalimide analogs containing an indole or brominated indole moiety were synthesized and their antimicrobial activity was evaluated. Compound 8 showed a broad spectrum activity, revealing 53-67% of erythromycin activity on the tested bacteria and 60-70% of miconazole activity on the tested fungi. Anticancer activity was evaluated on the cell lines HepG2, MCF-7, A549, H1299, and Caco2. The results revealed that the new phthalimide analog 8 has broad-spectrum anticancer activity toward all the tested cancer cell lines, followed by compound 11, which showed good activity toward all the tested cell lines except for MCF-7. The ability of the promising analogs 5, 8, and 11 to bind to topoisomerase II DNA gyrase was investigated. Caspase-3 activation and Bcl-2 assay of the best active derivatives 8, 11 in addition to compound 5 were evaluated. The antifibrotic activity was studied in an in vivo model and the histopathological studies revealed that treatment with the new compound 8 improved the fibrotic liver tissues to normality.

Anticancer effects of novel thalidomide analogs in A549 cells through inhibition of vascular endothelial growth factor and matrix metalloproteinase-2.

Lung cancer is one of the major causes of cancer-related mortality worldwide, and non-small-cell lung cancer is the most common form of lung cancer. Several studies had shown that thalidomide has potential for prevention and therapy of cancer. Therefore, the current study aimed to investigate the antitumor effects of two novel thalidomide analogs in human lung cancer A549 cells. The antiproliferative, antimigratory, and apoptotic effects in A549 cells induced by thalidomide analogs were examined. In addition, their effects on the expression of mRNAs encoding vascular endothelial growth factor165 (VEGF165) and matrix metalloproteinase-2 (MMP-2) were evaluated. Their influence on the tumor volume in nude mice was also determined. Results revealed that thalidomide analogs exhibited antiproliferative, antimigratory, and apoptotic activities with more pronounced effect than thalidomide drug. Furthermore, analogs 1 and 2 suppressed the expression levels of VEGF165 by 42% and 53.2% and those of MMP-2 by 45% and 52%, respectively. Thalidomide analogs 1 and 2 also reduced the tumor volume by 30.11% and 53.52%, respectively. Therefore, this study provides evidence that thalidomide analogs may serve as a new therapeutic option for treating lung cancer.

In vitro anti-proliferative and anti-angiogenic activities of thalidomide dithiocarbamate analogs.

Inhibition of angiogenesis is currently perceived as a promising strategy in the treatment of cancer. The anti-angiogenicity of thalidomide has inspired a second wave of research on this teratogenic drug. The present study aimed to investigate the anti-proliferative and anti-angiogenic activities of two thalidomide dithiocarbamate analogs by studying their anti-proliferative effects on human umbilical vein endothelial cells (HUVECs) and MDA-MB-231 human breast cancer cell lines. Their action on the expression levels of IL-6, IL-8, TNF-α, VEGF165, and MMP-2 was also assessed. Furthermore, their effect on angiogenesis was evaluated through wound healing, migration, tube formation, and nitric oxide (NO) assays. Results illustrated that the proliferation of HUVECs and MDA-MB-231 cells was not significantly affected by thalidomide at 6.25-100µM. Thalidomide failed to block angiogenesis at similar concentrations. By contrast, thalidomide dithiocarbamate analogs exhibited significant anti-proliferative action on HUVECs and MDA-MB-231 cells without causing cytotoxicity and also showed powerful anti-angiogenicity in wound healing, migration, tube formation, and NO assays. Thalidomide analogs 1 and 2 demonstrated more potent activity to suppress expression levels of IL-6, IL-8, TNF-α, VEGF165, and MMP-2 than thalidomide. Analog 1 consistently, showed the highest potency and efficacy in all the assays. Taken together, our results support further development and evaluation of novel thalidomide analogs as anti-tumor and anti-angiogenic agents.

Mouse induced pluripotent stem cell microenvironment generates epithelial-mesenchymal transition in mouse Lewis lung cancer cells.

Induced pluripotent stem (iPS) cells may be a powerful tool in regenerative medicine, but their potential tumorigenicity is a significant challenge for the clinical use of iPS cells. Previously, we succeeded in converting miPS cells into cancer stem cells (CSCs) under the conditions of tumor microenvironment. Both stem cells and tumor cells are profoundly influenced by bi-directional communication with their respective microenvironment, which dictates cell fate determination and behavior. The microenvironment derived from iPS cells has not been well studied. In this paper, we have investigated the effects of secreted factors from Nanog-mouse iPS (miPS) cells on mouse Lewis lung cancer (LLC) cells that are found in the conditioned media. The results demonstrated that miPS cells secrete factors that can convert the epithelia phenotype of LLC cells to a mesenchymal phenotype, and that can promote tumorigenisity, migration and invasion. Furthermore, LLC cells that have been exposed to miPS conditioned medium became resistant to apoptosis. These various biological effects suggest that the miPS microenvironment contain factors that can promote an epithelial-mesenchymal transition (EMT) through an active Snail-MMP axis or by suppressing differentiation in LLC cells.

Identification of caveolin-1 as a potential causative factor in the generation of trastuzumab resistance in breast cancer cells.

The oncogenic tyrosine kinase receptor ErbB2 is a prognostic factor and target for breast cancer therapeutics. In contrast with the other ErbB receptors, ErbB2 is hardly internalized by ligand induced mechanisms, indicating a prevalent surface expression. Elevated levels of ErbB2 in tumor cells are associated with its defective endocytosis and down regulation. Here we show that caveolin-1 expression in breast cancer derived SKBR-3 cells (SKBR-3/Cav-1) facilitates ligand induced ErbB2 endocytosis using an artificial peptide ligand EC-eGFP. Similarly, stimulation with humanized anti ErbB2 antibody Trastuzumab (Herceptin) was found to be internalized and co-localized with caveolin-1 in SKBR-3/Cav-1 cells. Internalized EC-eGFP and Trastuzumab in SKBR-3/Cav-1 cells were then delivered via caveolae to the caveolin-1 containing early endosomes. Consequently, attenuated Fc receptor mediated ADCC functions were observed when exposed to Trastuzumab and EC-Fc (EC-1 peptide conjugated to Fc part of human IgG). On the other hand, this caveolae dependent endocytic synergy was not observed in parental SKBR-3 cells. Therefore, caveolin-1 expression in breast cancer cells could be a predictive factor to estimate how cancer cells are likely to respond to Trastuzumab treatment.