Antineoplastic Potential Research Articles

Repurposing Leflunomide for Relapsed/Refractory Multiple Myeloma: A Phase 1 Trial

Introduction: Survival for patients with relapsed/refractory multiple myeloma (RRMM) remains poor; new, well-tolerated and effective treatments are needed. Leflunomide is a commercially available immunosuppressive agent that has been FDA approved since 1998 for the treatment of rheumatoid arthritis. The primary mechanism of action is inhibition of de novo pyrimidine synthesis by targeting dihydroorotate dehydrogenase (DHODH) and thus achieving anti-proliferative effects on B and T lymphocytes. A secondary mechanism of action is inhibition of cytokine and growth factor receptor associated tyrosine kinase activity. Leflunomide has been investigated for its anti-neoplastic potential in a variety of pre-clinical tumor models including multiple myeloma. This study explores the repurposing of leflunomide as a treatment for RRMM.Methods: This phase 1 dose-escalation trial is of single-agent leflunomide in patients with RRMM. Patient enrollment began in December 2015. The study implements a modified rolling six phase 1 dose escalation design. Primary objectives: 1) to determine the maximum tolerated dose and recommended phase 2 dose of leflunomide; 2) to assess the safety and tolerability of leflunomide at each dose level by evaluation of toxicities. Leflunomide is administered using a loading dose of 100 mg daily for the first three days followed by daily dosing in 28-day cycles. The starting dose of daily leflunomide is 20 mg daily, with dose escalation in increments of 20 mg/day, and dose de-escalation in decrements of 10 mg/day. The maximum dose to be tested is 60 mg/day.Results: A total of 10 patients have been enrolled and treated. Median age is 68 (range 48 - 85), median number of prior therapies is 5 (range: 3 - 14), and 9 patients had prior transplant. Double refractory (lenalidomide/bortezomib) disease was noted in 7 patients. One patient discontinued leflunomide for reasons unrelated to toxicity early during cycle 1 and is therefore inevaluable for toxicity or response and was replaced. Nine patients are evaluable for toxicity (see table). Of these patients, the median number of cycles was 3 (range 1- 15). Median follow up is 253 days (range: 28 - 602). High-risk cytogenetics were observed in 5 patients including 2 patients with del17p. One of the nine patients remains on treatment, 7 patients were removed from study due to disease progression, and one was removed because of an adverse event unrelated to study drug that caused delay in treatment. Three patients were treated on DL 1 (20 mg), three on DL3 (40 mg), and 4 patients, thus far, on DL5 (60 mg). The most common toxicities were hematologic. There were 4 patients with grade 1 or 2 neutropenia on the 20 and 40 mg dose levels and 1 patient with grade 4 lymphopenia on the 40 mg dose. All non-hematologic toxicities were ≤ grade 2. There were no DLTs reported at the first three dose levels. Adequate hepatic clearance and tolerance was noted, even in this older population.Response: Eight patients were evaluable for response. While not all patients were treated at the 60 mg dose, a clinical benefit rate of 88% has been seen, with 7/8 achieving stable disease (SD). The median duration of SD among 7 patients thus far is 152 days (range: 0-401). In the four evaluable patients with high risk cytogenetics, all of them achieved a clinical benefit with stable disease.Conclusion: Leflunomide is a safe and well-tolerated option for patients with RRMM. Hematologic responses have not yet occurred at current dosing, but a clinical benefit with single agent dosing has been observed. Additional testing of leflunomide at higher doses and in combination with dexamethasone for RRMM is planned. Moreover, because leflunomide is oral, well tolerated and relatively inexpensive at a cost of approximately $200/month, further investigation as a single agent at earlier stages of disease including high-risk smoldering myeloma is warranted. [Display omitted] DisclosuresRosenzweig:Celgene: Speakers Bureau. Krishnan:Onyx: Speakers Bureau; Janssen: Consultancy, Speakers Bureau; Celgene: Consultancy, Equity Ownership, Speakers Bureau; Takeda: Speakers Bureau; Sutro: Consultancy.

The phytochemical constituents and therapeutic uses of genus Aloe: A review

Aloe, the largest genus in the Asphodelaceae family, comprises 548 species, with A. vera, A. arborescens and A. ferox being among the most widely studied species. Aloe species originated in arid climates and cover various habitats, from sea level up to 2700 m, and from desert to closed-canopy forests. For human health, Aloe species are the richest natural sources. The biological activity of Aloe sp. constituents covers a wide spectrum. Most of the indications come from traditional, folkloric use and several have been verified by in vitro or in vivo studies. Emodin, the main phenolic component, has showed anti-neoplastic, anti-inflammatory, anti-angiogenic and toxicological potential for use in pharmacology. Polysaccharides, with acemannan being the most important, are present in high abundance in Aloe gels. Acemannan has been reported to have applications in oral, metabolic and cardiovascular diseases, oncology, dentistry and wound healing. The effectiveness of Aloe sp. constituents on colon, liver, duodenum, skin, pancreas, intestine, lungs and kidneys cancers was highly studied with remarkable findings. Regarding the metabolic syndrome, Aloe sp. can be used as an antidiabetic and reduces cholesterol and total body fat. Constituents of Aloe sp. are nontoxic in experimental acute oral studies and are widely used in cosmetology and as bitter agents or consistence modifiers in food and beverages. Traditional Aloe remedies cover most human diseases; however, in order to gain legitimacy, the Aloe-derived drugs must have a well-established composition, with thoroughly investigated adverse effects and conventional drug interactions.

Anacardic Acids from Amphipterygium adstringens Confer Cytoprotection against 5-Fluorouracil and Carboplatin Induced Blood Cell Toxicity While Increasing Antitumoral Activity and Survival in an Animal Model of Breast Cancer.

Amphipterygium adstringens (cuachalalate) contains anacardic acids (AAs) such as 6-pentadecyl salicylic acid (6SA) that show immunomodulatory and antitumor activity with minimal or no secondary adverse effects. By contrast, most chemotherapeutic agents, such as 5-fluorouracil (5-FU) and carboplatin (CbPt), induce myelosuppression and leukopenia. Here, we investigated the myeloprotective and antineoplastic potential of an AA extract or the 6SA as monotherapy or in combination with commonly used chemotherapeutic agents (5-FU and CbPt) to determine the cytoprotective action of 6SA on immune cells. Treatment of Balb/c breast tumor-bearing female mice with an AA mixture or 6SA did not induce the myelosuppression or leukopenia observed with 5-FU and CbPt. The co-administration of AA mixture or isolated 6SA with 5-FU or CbPt reduced the apoptosis of circulating blood cells and bone marrow cells. Treatment of 4T1 breast tumor-bearing mice with the AA mixture or 6SA reduced tumor growth and lung metastasis and increased the survival rate compared with monotherapies. An increased effect was observed in tumor reduction with the combination of 6SA and CbPt. In conclusion, AAs have important myeloprotective and antineoplastic effects, and they can improve the efficiency of chemotherapeutics, thereby protecting the organism against the toxic effects of drugs such as 5-FU and CbPt.

New drug candidates for osteosarcoma: Drug repurposing based on gene expression signature

Osteosarcoma (OS) is an aggressive bone malignancy and the third most common cancer in adolescence. Since the late 1970s, OS therapy and prognosis had only modest improvements, making it appealing to explore new tools that could help ameliorate the treatment. We present a meta-analysis of the gene expression signature of primary OS, and propose small molecules that could reverse this signature. The meta-analysis was performed using GEO microarray series. We first compared gene expression from eleven primary OS against osteoblasts to obtain the differentially expressed genes (DEGs). We later filtered those DEGs by verifying which ones had a concordant direction of differential expression in a validation group of 82 OS samples versus 30 bone marrow mesenchymal stem cells (BM-MSC) samples. A final gene expression signature of 266 genes (98 up and 168 down regulated) was obtained. The L1000CDS2 engine was used for drug repurposing. The top molecules predicted to reverse the signature were afatinib (PubChem CID 10184653), BRD-K95196255 (PubChem CID 3242434), DG-041 (PubChem CID 11296282) and CA-074 Me (PubChem CID 23760717). Afatinib (Gilotrif™) is currently used for metastatic non-small-cell lung cancer with EGFR mutations, and in vitro evidence shows antineoplastic potential in OS cells. The other three molecules have reports of antineoplastic effects, but are not currently FDA-approved. Further studies are necessary to establish the potential of these drugs in OS treatment. We believe our results can be an important contribution for the investigation of new therapeutic genetic targets and for selecting new drugs to be tested for OS.

Estudos In silico sobre as atividades anticancerígenas do Eugenol presente no Cravo Da Índia (Syzygium aromaticum)

Objetivo: Investigar as propriedades anticancerígenas do eugenol usando métodos In silico. Metodologia: é um artigo original utilizando a metodologia In silico atraves dos softwares PASS (Prediction of activity spectra for substances) online e GUSAR disponíveis de forma gratuita e livre. Resultados: Os resultados do sistema operacional online PASS demonstraram diversas atividades biológicas positiva, tais quais efeito antimutagênico, estimulante de caspase, tratamento pré neoplásico e agonista de apoptose tendo uma probabilidade de atividade (PA) bem superior a 0,700. Tais achados reforçam aos descritos na literatura que evidenciam um potencial antineoplásico devido o componente ter efeitos antioxidante, e estar vinculado a expressão de genes envolvidos na apoptose e inflamação. Tal como efeitos na regulação negativa de Bcl-2, COX-2 e IL-1ß, e ações na regulação positiva de P53, Bax e expressão ativa de Caspase-3, caspase-9 além de induzir a via da apoptose mitocondrial. Já pelo software GUSAR, foi observado a toxicidade, demonstrando que na categoria 4, estão as vias de administração intravenosa, oral, e subcutânea, indicando que é pouco tóxico. Já na categoria 5 enquadra-se a via intraperitoneal é relativamente atóxico. Tal achado ainda é obscuro e possui poucos artigos científicos para o embasamento. Conclusão: O Eugenol possui efeitos favoráveis para o tratamento e prevenção de diversos canceres e células mutagênicas, porém ainda há pouco conhecimento sobre a toxicidade deste componente. Assim, necessita de um maior aprofundamento sobre a temática.

Prevention of doxorubicin-induce renal function abnormalities by turmeric in Wistar rats

Doxorubicin is an anthracycline antibiotic with anti-neoplastic potentials mediated mainly by affecting the DNA synthetic machinery of the cell. It is found to be effective against a wide range of cancers including the ovary, uterus, lung, breast etc. Doxorubicin exerts its nephrotoxicity on the kidney by inducing inflammatory changes leading to increased capillary porousness and glomerular shrinking. This study investigated the effect of turmeric on the renal function biomarkers in doxorubicin-induced oxidative stress in Wistar rats. 54 adult Wistar rats were divided into 9 groups of six animals each. Group 1 animals served as control (normal saline), group 2 animals served as negative control, and received doxorubicin, group 3 animals were given doxorubicin and turmeric, group 4 animals received doxorubicin and vitamin C, group 5 animals received doxorubicin and vitamin E, group 6 animals received doxorubicin, vitamins C and turmeric, group 7 animals received doxorubicin, vitamin E and turmeric, while group 8 animals received doxorubicin, vitamin C and vitamin E and finally, group 9 animals receive doxorubicin, vitamin C, vitamin E and turmeric. The experiment lasted for 28 days and blood samples were collected from each animal from the various groups for renal function assay. Doxorubicin caused significant increase in the serum levels of urea, creatinine, sodium (Na+), calcium (Ca2+), and decrease serum levels of chloride (Cl-), magnesium (Mg2+) and potassium (K+). These abnormal electrolyte imbalances were prevented by administration of turmeric alone or in combination with vitamins C and or E along with doxorubicin concomitantly.

Multimodal treatment combining cold atmospheric plasma and acidic fibroblast growth factor for multi‐tissue regeneration

Cold atmospheric plasma (CAP) is an emerging technology for biomedical applications, exemplified by its antimicrobial and antineoplastic potentials. On the contrary, acidic fibroblast growth factor (aFGF) has been a long-standing potent mitogen for cells from various origins. In this study, we are the first to develop a multimodal treatment combining the aforementioned physicochemical and pharmacological treatments and investigated their individual and combined effects on wound healing, angiogenesis, neurogenesis, and osteogenesis. This work was performed at the tissue, cellular, protein, and gene levels, using histochemical staining, flow cytometry, ELISA, and PCR, respectively. Depending on the type of target tissue, various combinations of aforementioned methods were used. The results showed that the enhancement on would healing and angiogenesis by CAP and aFGF were synergistic. The former was manifested by increased murine fibroblast proliferation and reduced cutaneous tissue inflammation, whereas the latter by upregulated proangiogenic markers in vivo, for example, CD31, VEGF, and TGF-β, and downregulated antiangiogenic proteins in vitro, for example, angiostatin and angiopoietin-2, respectively. In addition, aFGF outperformed CAP during neurogenesis, which was evidenced by superior neurite outgrowth, while CAP exceeded aFGF in osteogenesis which was demonstrated by more substantial bone nodule formation. These novel findings not only support the fact that CAP and aFGF are both multipotent agents during tissue regeneration, but also highlight the potential of our multimodal treatment combining the individual advantages of CAP and aFGF. The versatile administration route, that is, topical and/or systemic, might further broaden its applications.

Activation of anti-oxidant Keap1/Nrf2 pathway modulates efficacy of dihydroartemisinin-based monotherapy and combinatory therapy with ionizing radiation

The efficacy of radiotherapy depends not only on DNA damage but also on ROS production, both induced by ionizing radiation. Massive ROS production can induce cell death or activate protective pathways such as Keap1/Nrf2 pathway, which regulates intracellular cysteine availability through upregulation of SLC7A11, a subunit of xCT transporter, and subsequently glutathione synthesis, thus improving antioxidative defense. The anti-malaria drug dihydroartemisinin (DHA) shows anti-neoplastic potential. Previous publications suggested that DHA increased ROS production. We intended to enhance oxidative stress with DHA to improve the efficacy of radiotherapy. Therefore, we first analyzed the oxidative response to DHA in HCT116 colorectal and NCI–H460 lung adenocarcinoma cells. In response to DHA, we detected lipid peroxidation and protein oxidation, which resulted in mitochondrial damage and eventually in iron-dependent cell death. Concurrently, DHA activated Keap1/Nrf2 pathway in HCT116 cells, leading to increased SLC7A11 expression and glutathione level. In Keap1-mutant NCI–H460 cells, Nrf2 was constantly activated and responsible for high SLC7A11 and glutathione levels. Pancancer analysis revealed that lung cancer is the tumor entity with the most frequent Keap1 alterations. Although NCI–H460 cells reacted more refractory to DHA-induced cell death than HCT116 cells, eradication of clonogenic cells by DHA was more efficient in both cell lines when Keap1/Nrf2 pathway was inhibited. When applied simultaneously, radiotherapy and DHA more efficiently eradicated clonogenic cells than either therapy alone, but treatment schedule can mitigate the combinatory effect in HCT116 cells. In summary, DHA improved efficacy of radiotherapy, but treatment schedule must be considered with care especially in Keap1-wildtype cells.

Enzymatically Extracted Apple Pectin Possesses Antioxidant and Antitumor Activity.

The biological activity of apple pectin extracted conventionally or enzymatically using endo-xylanase and endo-cellulase, was tested in vitro. The analyses were performerd in tetraplicates and the statistical significance of the differences were assessed using ANOVA, Tukey post hoc and LSD (the least significant difference) tests. Multivariate regression analysis was applied to determine the structural components that have a crucial importance for antioxidant and antitumor properties of pectins. The pectins extracted by enzymes contained up to four times more ferulic acid and showed twice as great ability to neutralize free radicals and Fe(III) reduction. The antiradical potential positively correlated with phenols, fucose and rhamnose content. In the assays performed on HT-29 human adenocarcinoma and B16F10 melanoma cell cultures, the “green” pectins, contrary to acid isolated ones, exhibited remarkable anti-neoplastic potential while being nontoxic to nontransformed L929 cell line. The pectins in the dose of 1 mg/mL were capable of inhibiting adhesion (max 23.1%), proliferation (max 40.4%), invasion (max 76.9%) and anchorage-independent growth (max 90%) of HT-29 cells (significance level p < 0.001). These pectin preparations were slightly less active towards B16F10 cells. The enzyme-isolated apple pectins may be useful as a functional food additive and an ingredient of the ointment formulas for post-surgical melanoma treatment.

Tumor Decelerating and Chemo-Potentiating Action of Methyl Jasmonate on a T Cell Lymphoma In Vivo: Role of Altered Regulation of Metabolism, Cell Survival, Drug Resistance, and Intratumoral Blood Flow.

Methyl jasmonate (MJ), a natural oxylipin, possesses a broad spectrum of antineoplastic potential in vitro. However, its tumor growth impeding and chemo-potentiating action has not been adequately investigated in vivo. Using a murine thymus-derived tumor named Dalton’s Lymphoma (DL), in the present study, we examined if intra-tumoral administration of MJ can cause tumor growth impedance. We also explored the associated molecular mechanisms governing cell survival, carbohydrate & lipid metabolism, chemo-potentiation, and angiogenesis. MJ administration to tumor-transplanted mice caused deceleration of tumor growth accompanying prolonged survival of the tumor-bearing mice. MJ-dependent tumor growth retardation was associated with the declined blood supply in tumor milieu, cell cycle arrest, augmented induction of apoptosis and necrosis, deregulated glucose and lipid metabolism, enhanced membrane fragility of tumor cells, and altered cytokine repertoire in the tumor microenvironment. MJ administration modulated molecular network implicating Hsp70, Bcl-2, TERT, p53, Cyt c, BAX, GLUT-1, HK 2, LDH A, PDK-1, HIF-1α, ROS, MCT-1, FASN, ACSS2, SREBP1c, VEGF, cytokine repertoire, and MDR1, involved in the regulation of cell survival, carbohydrate and fatty acid metabolism, pH homeostasis, and drug resistance. Thus, the present study unveils novel molecular mechanisms of the tumor growth decelerating action of MJ. Besides, this preclinical study also establishes the adjunct therapeutic potential of MJ. Hence, the present investigation will help to design novel anti-cancer therapeutic regimens for the treatment of hematological malignancies.

Antioxidant, genotoxic, antigenotoxic, and antineoplastic activities of apitoxin produced by Apis mellifera in Northeast, Brazil

ABSTRACT: The objective was to evaluate the in vitro antioxidant, genotoxic, antigenotoxic, and antineoplastic activities of apitoxin produced by the bee Apis mellifera. The antioxidant activity of the apitoxin solution was evaluated using the DPPH (2,2-diphenyl-1-picrilhydrazyl) method. Genotoxic potential of apitoxin was analyzed by comparing the mean DNA damage indices (idDNA) of L929 strain fibroblasts exposed to hydrogen peroxide (H2O2 - genotoxic substance), distilled water, or apitoxin. The antigenotoxic effect of apitoxin was analyzed by assessing the percentage decrease in H2O2-induced genotoxicity in L929 fibroblasts co-treated with three concentrations of the aqueous apitoxin solution and subjected to comet assay. In vitro antineoplastic activity in human tumor cell lines of prostate adenocarcinoma (PC3), hepatocellular carcinoma (HEPGE2), melanoma (MAD-MB435), and astrocytoma (SNB19), were verified by MTT [3- (4) bromide colorimetric method, 5-dimethylthiazol-2-yl) -2,5-diphenyltetrazolium]. Apitoxin had no genotoxic effect on L929 cells at concentrations of 30, 10, and 5 µg/mL after 24 hours of exposure. This effect was only evident at 50 µg/mL. Apitoxin promoted a significant reduction in DNA damage index (idDNA) at all concentrations tested. At 30 µg/mL, apitoxin attenuated the genotoxic effects induced by H2O2. Apitoxin also demonstrated in vitro antineoplastic potential, since the cytotoxic effect was observed at concentrations of 50 µg/mL and 25 µg/mL, with significant reduction in viability percentage of PC3 tumor cell lines, HEPGE2, MAD-MB435, and SNB19. The high antioxidant activity associated with the absence of genotoxic effect and the genoprotective and antineoplastic effect demonstrated by apitoxin here provide indications of apitoxin’s therapeutic potential.

Experimental and theoretical study on spectral features, reactivity, solvation, topoisomerase I inhibition and in vitro cytotoxicity in human HepG2 cells of guadiscine and guadiscidine aporphine alkaloids

In this study, guadiscine (G1) and guadiscidine (G2), 7,7-dimethylaporphine alkaloids from Guatteria friesiana, have they geometric paramaters, vibrational behavior and quantum chemical properties (HOMO-LUMO, MEP, ALIE and Fukui indices) analyzed through a theoretical view, by density functional theory (DFT), using the Becker's three-parameter hybrid exchange functional combined with the Lee–Yang–Parr correlation functional (B3LYP) and 6–311G(2d,p) and 6–311G++(2df,3p) basis sets. The obtained geometry data were compared with x-ray data for (−)-N-acetyl-anonaine, showing close values. Vibrational analysis, together with potential energy distribution (PED) calculations, revealed several characteristic vibrations that characterize the 7,7 dimethylaporphine skeleton, besides enabling the observation of intermolecular H-bonds through dimers formation. Molecular dynamic simulations were carried out, allowing to evaluate the solvation free energies of G1 and G2 in water, methanol and ethanol, as well as H-bonds formation between G1 and G2 and the tested solvents. The antineoplastic potential of the title molecules was evaluated via molecular docking calculations with topoisomerase I complexed with DNA. Guadiscine and guadiscidine showed, respectively, binding free energies of -8.0 and -8.5 kcal/mol, while topotecan, a DNA topoisomerase I inhibitor, showed a binding free energy value of -12 kcal/mol, indicating that the studied molecules are good topoisomerase I inhibitors. In vitro cytotoxicity assay with HepG2 cell line were performed, revealing significant antitumor potential for G2.

Sphingosine Analogs and Protein Phosphatase 2A as a Molecular Targeted Cancer Therapy: A Mini Systematic Review

Background: Regulation of protein phosphatase 2A (PP2A) plays an important role in hematologic and solid neoplasms. Therefore, the use of sphingosine analogs as anti-neoplastic drugs has shown potential due to their role as PP2A activators. Objective: Investigation of whether sphingosine analogs bind to endogenous inhibitor proteins of PP2A, such as I2 PP2A/SET and/or CIP2A, and whether this binding reactivates PP2A, allowing it to resume its role as a tumor suppressor. Methods: Literature from the PubMed database was searched and those articles related to PP2A and sphingosine analogs were reviewed. Results: Utilization of sphingosine analogs in hematologic and solid neoplasms revealed numerous mechanisms of inducing cell death. Regulation of PP2A through modulation of I2 PP2A/SET and/or CIP2A was demonstrated in a variety of neoplastic processes; however, unique mechanisms such as cell necrosis via the production of reactive oxygen species was also appreciated. Conclusion: Only certain malignancies expressed endogenous inhibitor proteins, yet sphingosine analogs were able to induce cell death in neoplasms that did not express these proteins. This suggests that sphingosine analogs may be utilized for anti-neoplastic therapy via reactivation of PP2A however, it is not the exclusive mechanism for inducing cell death. Further investigation of sphingosine analogs as a novel or adjunctive chemotherapeutic treatment is warranted.

Novel chalcones derivatives with potential antineoplastic activity investigated by docking and molecular dynamics simulations

Glioblastoma is an aggressive primary tumor of the central nervous system (CNS). Is the most aggressive among infiltrative gliomas arising from the CNS. This tumor has low patient survival rate and several studies aiming at developing new drugs have increased. Patients with this cancer type face significant morbidity and mortality. This study evaluated the antineoplastic activity of synthetic chalcones (3a-3f) using in vitro glioblastoma models and molecular modeling. Cytotoxicity assay showed that Astrocitoma Hospital Ofir Loyola No 1 (AHOL1) and Uppsala 87 neoplastic glioblastoma lines (U87) cellular viability were significantly reduced compared to Healthy human fibroblasts cell lines (AN27) when exposed to chalcones. Interaction with the serine amino acid was present in the most promising and the reference binder docking, suggesting its importance inhibiting cell growth. Comparative analysis between the reference ligands and the molecules showed that the amino acid LYS352 present in all fittings, suggesting that this is the main amino acid for interaction with tubulin and are consistent with those in cytotoxicity assay, suggesting antineoplastic potential in glioblastoma. Long trajectory molecular dynamics studies were also carried out in order to investigate stability and conformations amongst the chalcones bound tubulin as well, in comparison to doxorubicin (here used as control), however future studies are needed to further assess the mechanism of inhibition of chalcones used in this investigation. Communicated by Ramaswamy H. Sarma

Anti-neoplastic Potential of Flavonoids and Polysaccharide Phytochemicals in Glioblastoma.

Clinically, gliomas are classified into four grades, with grade IV glioblastoma multiforme being the most malignant and deadly, which accounts for 50% of all gliomas. Characteristically, glioblastoma involves the aggressive proliferation of cells and invasion of normal brain tissue, outcomes as poor patient prognosis. With the current standard therapy of glioblastoma; surgical resection and radiotherapy followed by adjuvant chemotherapy with temozolomide, it remains fatal, because of the development of drug resistance, tumor recurrence, and metastasis. Therefore, the need for the effective therapeutic option for glioblastoma remains elusive. Previous studies have demonstrated the chemopreventive role of naturally occurring pharmacological agents through preventing or reversing the initiation phase of carcinogenesis or arresting the cancer progression phase. In this review, we discuss the role of natural phytochemicals in the amelioration of glioblastoma, with the aim to improve therapeutic outcomes, and minimize the adverse side effects to improve patient’s prognosis and enhancing their quality of life.

Marine bioprospecting: Investigating new bioactive compounds with antineoplastic potential in glioblastoma

Background: Glioblastoma is the most malignant brain tumor of the central nervous system, with a high rate of proliferation and invasive growth, which limits its treatment. Cyanobacteria are photoautotrophic prokaryote organisms, recognized as major producers of secondary metabolites with unique structural characteristics, presenting anti-inflammatory and antitumor activities. The aim of this study was to evaluate the antitumoral effect of extracts from different species of marine cyanobacteria in human glioblastoma cells.

Assessments of in vitro and in vivo antineoplastic potentials of β-sitosterol-loaded PEGylated niosomes against hepatocellular carcinoma

β-sitosterol (BS), a phytosterol, exhibits ameliorative effects on hepatocellular carcinoma (HCC) due to its antioxidant activities. However, its poor aqueous solubility and negotiated bioavailability and short elimination half-life is a huge limitation for its therapeutic applications. To overcome these two shortcomings, BS-loaded niosomes were made to via, film hydration method and process parameters were optimized using a three-factor Box–Behnken design. The optimized formulation (BSF) was further surface-modified with polyethylene glycol (PEG). The resulting niosomes (BSMF) have spherical shapes, particle sizes, 219.6 ± 1.98 nm with polydispersity index (PDI) and zeta potential of 0.078 ± 0.04 and −19.54 ± 0.19 mV, respectively. The drug loading, entrapment efficiency, and drug release at 24 h of the BSMF were found to be 16.72 ± 0.09%, 78.04 ± 0.92%, and 75.10 ± 3.06%, respectively. Moreover, BSMF showed significantly greater cytotoxic potentials on Hep G2 cells with an enhanced cellular uptake relative to pure BS and BSF. The BSMF also displayed potentially improved curative property of HCC in albino wistar rat. Thus, the BSMF could be one of the promising therapeutic modalities for HCC treatment in terms of targeting potential resulting in enhanced therapeutic efficacy.

The anti-malaria agent artesunate exhibits cytotoxic effects in primary effusion lymphoma.

Primary effusion lymphoma (PEL), caused by Kaposi's sarcoma-associated herpesvirus (KSHV), presents as a lymphomatous effusion in body cavities and has a poor prognosis. The anti-malaria drug, artesunate, possesses anti-neoplastic potential. Therefore, we aimed to investigate its effect on KSHV-infected PEL cell lines. Artesunate inhibited cell growth and viability of PEL cells, but its effect on peripheral blood mononuclear cells was less pronounced. Artesunate induced G1 phase arrest by downregulating cyclin D1/D2, CDK2/6 and c-Myc. Artesunate increased reactive oxygen species and DNA damage, but did not affect the expression of latent and lytic genes of KSHV. It exhibited cytotoxicity through caspase-dependent and -independent pathways and reduced Bcl-xL, survivin, XIAP and c-IAP1/2 levels. Furthermore, artesunate suppressed NF-κB and AP-1 by inhibiting IκB kinase and IκBα phosphorylation as well as JunB expression. Finally, artesunate treatment attenuated PEL development in mice. Our data support that artesunate is a potential drug for PEL treatment.

Abstract 612: ONC212 affects ClpXP complex, impairs mitochondrial bioenergetics and synergizes with glycolysis inhibition in pancreatic cancer

Abstract Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest human cancers and still represents an unmet clinical need. Survival, proliferation and drug-resistance of pancreatic cancer cells are driven by KRAS mutation, which supports both mitochondrial and glycolytic bioenergetics. ONC212 is a fluorinated imipridone with cytotoxic activity against pancreatic cancer cell lines and patient-derived xenografts. It has been reported to bind to and hyperactivate ClpXP, a mitochondrial protease composed by the regulatory subunit ClpX and the catalytic chamber ClpP, which is involved in the maintenance of respiratory chain function. Here we evaluated the effect of ONC212 on ClpXP expression in a panel of pancreatic cancer cell lines and investigated the metabolic changes occurring in vitro upon ONC212 exposure. Western blot analysis showed that ONC212 destabilized ClpXP complex through the suppression of its regulatory subunit ClpX, while leaving ClpP relatively unaffected. NDUFA12, SDH-A and SDH-B, three ClpP substrates belonging to the respiratory chain complexes I and II, decreased after treatment with ONC212. Moreover, ClpP transient knockdown partially protected cancer cells from ONC212 cytotoxicity. Seahorse XF ATP assay revealed that mitochondrial ATP production was impaired by ONC212, while glycolytic ATP proportionally increased. Accordingly, ONC212 caused a dose-dependent accumulation of lactate in culture supernatant along with the restoration of NAD+, an essential coenzyme fueling glycolytic flux. Interestingly, there was an inverse correlation between basal mitoATP% and ONC212 GI50. Furthermore, AsPC1, one of the most sensitive cell lines, was far less efficient in upregulating glycolysis as compared to the others and suffered a profound decline in ATP production. As a consequence of bioenergy imbalance, AMPK became phosphorylated at Thr172 upon ONC212 treatment in most cell lines. Culturing PDAC cells in galactose-containing medium, favoring mitochondrial metabolism over glycolysis, sensitized them to ONC212. Conversely, hypoxia, which forces cancer cells to generate ATP through glycolysis, rendered them more resistant to the drug. The combination of ONC212 plus 2-Deoxy-d-Glucose, an inhibitor of the first steps of the glycolytic pathway, resulted in highly synergistic loss of cell viability. In addition, the combination treatment, but not ONC212 alone, inhibited ERK1/2 phosphorylation and induced PARP cleavage in PANC1 and BxPC3 cells. Overall, ONC212 targets ClpXP and compromises mitochondrial bioenergetics in pancreatic cancer. Enhancement of glycolytic flux may represent an escape mechanism active in most PDAC cells. Switching metabolic dependence towards mitochondria or combining ONC212 with a glycolytic inhibitor may significantly increase its antineoplastic potential in this highly aggressive malignancy. Citation Format: Isacco Ferrarini, Lanlan Zhou, Wafik S. El-Deiry. ONC212 affects ClpXP complex, impairs mitochondrial bioenergetics and synergizes with glycolysis inhibition in pancreatic cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 612.

An analysis of mitotic catastrophe induced cell responses in melanoma cells exposed to flubendazole

Mitotic catastrophe induced by mictotubule-targeting drugs such as benzimidazole carbamates has been demonstrated to be an efficient mechanism for suppression of tumor cells growth and proliferation, with variable resulting endpoints. The present study was designed to explore some of these endpoints; i.e. the apoptosis as well as autophagy and their related signaling in several stabilized cell lines as well as human explant melanoma cells treated with flubendazole (FLU). FLU-induced mitotic catastrophe resulted in mitochondrial and caspase-dependent apoptosis, which occurred at various rates in all treated cells during 96 h of treatment. The process was characterized by enhanced transcriptional activity of TP53 and NF-κB as well as upregulated Noxa expression. Also, inactivation of Bcl-2, BclXL and Mcl-1 proteins by JNK mediated phosphorylation was observed. Although increased autophagic activity took place in treated cells too, no discernible functional linkage with ongoing cell death process was evidenced. Together these results advance our evidence over the effectiveness of FLU cytotoxicity-related killing of melanoma cells while calling for more extensive testing of melanoma samples as a prerequisite of further preclinical evaluation of FLU antineoplastic potential.