Synthetic phosphoethanolamine a precursor of membrane phospholipids reduce tumor growth in mice bearing melanoma B16-F10 and in vitro induce apoptosis and arrest in G2/M phase

Ethanolamine-phosphate phospho-lyase (ETNPPL) contributes to the diagnosis, prognosis, and therapy of hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is characterized by high mortality, difficulty in early screening, relapse, and poor prognosis. This study aimed to explore the expression of ethanolamine-phosphate phospho-lyase (ETNPPL) and its clinical significance in HCC.

Methods

Differentially expressed mRNAs were screened using microarray analysis. Functional enrichment was performed using GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis. We used qRT-PCR to measure the expression of ETNPPL in HCC tissues and paired paracarcinoma tissues. A receiver operating characteristic (ROC) curve and Kaplan-Meier curve were conducted to assess the diagnostic and prognostic values. Cell behaviors were evaluated using a scratch test and transwell assay.

Results

The results showed that numerous mRNAs are abnormally expressed in HCC. ETNPPL was decreased in HCC tissues and cells. The area under curve (AUC) of ETNPPL was 0.9089, demonstrating that ETNPPL had diagnostic value. Low expression of ETNPPL was related to poor prognosis for patients with HCC. Moreover, the over-expression of ETNPPL inhibited HCC cell migration and invasion.

Conclusions

In conclusion, downregulated ETNPPL was found in HCC and is related to poor patient prognosis and the promotion of cell metastasis. This suggests that ETNPPL serves both as a promising diagnosis and prognosis biomarker, and a therapy target of HCC.

Bilayer Forming Phospholipids as Targets for Cancer Therapy

Phospholipids represent a crucial component for the structure of cell membranes. Phosphatidylcholine and phosphatidylethanolamine are two phospholipids that comprise the majority of cell membranes. De novo biosynthesis of phosphatidylcholine and phosphatidylethanolamine occurs via the Kennedy pathway, and perturbations in the regulation of this pathway are linked to a variety of human diseases, including cancer. Altered phosphatidylcholine and phosphatidylethanolamine membrane content, phospholipid metabolite levels, and fatty acid profiles are frequently identified as hallmarks of cancer development and progression. This review summarizes the research on how phospholipid metabolism changes over oncogenic transformation, and how phospholipid profiling can differentiate between human cancer and healthy tissues, with a focus on colorectal cancer, breast cancer, and non-small cell lung cancer. The potential for phospholipids to serve as biomarkers for diagnostics, or as anticancer therapy targets, is also discussed.

Local tumour response to neoadjuvant therapy with 2-aminoethyl dihydrogen phosphate in dogs with soft tissue sarcoma

BACKGROUND

In cases of soft tissue sarcoma (STS), neoadjuvant therapy is indicated to downstage the tumour prior to surgery to achieve enhanced local tumour control. The antineoplastic phospholipid compound 2-aminoethyl dihydrogen phosphate (2-AEH2F) is an alkyl phosphate ester capable of inhibiting cell proliferation and inducing cell death by modifying the asymmetry of phospholipids in the cytoplasmic membrane OBJECTIVES: This clinical study was designed to investigate local antitumoural effects of neoadjuvant therapy with 2-AEH2F in dogs with naturally occurring STS MATERIAL AND METHODS: Dogs (n = 11) received four consecutive weekly intravenous injections of 2-AEH2F (70 mg/kg) prior to tumour resection. Tomographic (CT) and thermal (TE) images were used to investigate changes in tumour size and local temperature in response to treatment RESULTS: Comparative analysis of CT images (n = 9/11) failed to reveal complete or partial remission according to selected assessment criteria (RECIST, WHO and volumetric). Comparative analysis of TE images (n = 10/11) revealed significantly (p = 0.01416) lower temperatures in tumoural areas relative to surrounding tissues over the course of treatment CONCLUSIONS: 2-AEH2F had no cytoreductive effects when used at doses and intervals described in this study. However, significant drop in skin temperatures recorded in tumoural areas suggest induction of physiological changes.

Antiproliferative and proapoptotic effects of DODAC/synthetic phosphoethanolamine on hepatocellular carcinoma cells

BACKGROUND

Current studies have demonstrated that DODAC/PHO-S (Dioctadecyldimethylammonium Chloride/Synthetic phosphoethanolamine) liposomes induces cytotoxicity in Hepa1c1c7 and B16F10 murine tumor cells, with a higher proportion than PHO-S. Therefore, our aim was to evaluate the potential of DODAC/PHO-S to elucidate the mechanism of cell death whereby the liposomes induces cytotoxicity in hepatocellular carcinoma Hepa1c1c7, compared to the PHO-S alone.

METHODS

Liposomes (DODAC/PHO-S) were prepared by ultrasonication. The cell cycle phases, protein expression and types of cell's death on Hepa1c1c7 were analyzed by flow cytometry. The internalisation of liposomes, mitochondrial electrical potential and lysosomal stability were also evaluated by confocal laser scanning microscopy.

RESULTS

After treatment with liposomes (DODAC/PHO-S), we observed a significant increase in the population of Hepa1c1c7 cells experiencing cell cycle arrest in the S and G₂/M phases, and this treatment was significantly more effective to promote cell death by apoptosis. There also was a decrease in the mitochondrial electrical potential; changes in the lysosomes; nuclear fragmentation and catastrophic changes in Hepa1c1c7 cells. The liposomes additionally promoted increases in the expression of DR4 receptor, caspases 3 and 8, cytochrome c, p53, p21, p27 and Bax. There was also a decrease in the expression of Bcl-2, cyclin D1, CD90 and CD44 proteins.

CONCLUSION

The overall results showed that DODAC/PHO-S liposomes were more effective than PHO-S alone, in promoting cytotoxicity Hepa1c1c7 tumor cells, activating the intrinsic and extrinsic pathways of programmed cell death.

Phosphoethanolamine induces caspase-independent cell death by reducing the expression of C-RAF and inhibits tumor growth in human melanoma model

Phosphoethanolamine (PEA) is a fundamental precursor during the biosynthesis of cell membranes phospholipids. In the past few years, it has been described as a potential antitumor agent. In previous studies, we demonstrated that PEA showed antitumor properties in vitro and in vivo in a wide range of tumor cell lines. Herein, we showed that PEA possesses cytotoxic properties and notably revealed to induce caspase-independent cell death. Of interest, we provided evidence that PEA inhibits melanoma cells proliferation through the reduction of C-RAF. Molecular docking of PEA evidenced that this compound indeed fits satisfactory in the binding site located between the dimers of C-RAF protein with 107,01 Å and score of -29,62. Also, PEA arrested A2058 cells at G2/M phase in the cell cycle. Moreover, cell proliferation, migration and adhesion capacities of A2058 cells were also inhibited by PEA. Most importantly, PEA inhibited tumor growth of melanoma tumors and prolonged survival rate of mice. Also, PEA induced a significant immune response in a syngeneic metastatic melanoma model. Taken together, these data indicate that PEA is a promising candidate for future developments in cancer field.

Modulation of pro-apoptotic effects and mitochondrial potential on B16F10 cells by DODAC/PHO-S liposomes

Objective

We aimed to evaluate the potential of DODAC/PHO-S liposomes on the modulation of the expression of pro-apoptotic proteins, loss of lysosomal integrity and the mitochondrial electrical potential, compared with phosphoethanolamine.

Results

The results of this study demonstrate that DODAC/PHO-S liposomes have exhibited broad cytotoxic potential in B16F10 murine melanoma cells, with significantly greater proportions than treatment with PHO-S. The treatment with the DODAC/PHO-S 2.0 mM liposomal formulation was more efficient in decreasing mitochondrial electrical potential at the same concentrations and treatment time than PHO-S The liposomal formulation DODAC/PHO-S (2.0 mM) was more efficient to promote morphological changes in the cells, without presenting intact lysosomes, at the same time of treatment and concentration as PHO-S Our results demonstrated that the liposomal formulation increased DR4 receptor expression and activated caspases 8 and 3, resulting in the release of cytochrome c in B16F10 tumour cells, when compared to treatment with PHO-S The data obtained prove that the use of DODAC as carrier can maximize the cytotoxic effects of PHO-S This was demonstrated by the translocation of cytochrome c to the cytoplasm and activation of caspase-3 and 8, decreasing the mitochondrial electrical potential and generating morphological changes, in B16F10 cells.

Metabolomics-A Promising Approach to Pituitary Adenomas

Background: Metabolomics-the novel science that evaluates the multitude of low-molecular-weight metabolites in a biological system, provides new data on pathogenic mechanisms of diseases, including endocrine tumors. Although development of metabolomic profiling in pituitary disorders is at an early stage, it seems to be a promising approach in the near future in identifying specific disease biomarkers and understanding cellular signaling networks. Objectives: To review the metabolomic profile and the contributions of metabolomics in pituitary adenomas (PA). Methods: A systematic review was conducted via PubMed, Web of Science Core Collection and Scopus databases, summarizing studies that have described metabolomic aspects of PA. Results: Liquid chromatography tandem mass spectrometry (LC-MS/MS) and nuclear magnetic resonance (NMR) spectrometry, which are traditional techniques employed in metabolomics, suggest amino acids metabolism appears to be primarily altered in PA. N-acetyl aspartate, choline-containing compounds and creatine appear as highly effective in differentiating PA from healthy tissue. Deoxycholic and 4-pyridoxic acids, 3-methyladipate, short chain fatty acids and glucose-6-phosphate unveil metabolite biomarkers in patients with Cushing's disease. Phosphoethanolamine, N-acetyl aspartate and myo-inositol are down regulated in prolactinoma, whereas aspartate, glutamate and glutamine are up regulated. Phosphoethanolamine, taurine, alanine, choline-containing compounds, homocysteine, and methionine were up regulated in unclassified PA across studies. Intraoperative use of ultra high mass resolution matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI), which allows localization and delineation between functional PA and healthy pituitary tissue, may contribute to achievement of complete tumor resection in addition to preservation of pituitary cell lines and vasopressin secretory cells, thus avoiding postoperative diabetes insipidus. Conclusion: Implementation of ultra high performance metabolomics analysis techniques in the study of PA will significantly improve diagnosis and, potentially, the therapeutic approach, by identifying highly specific disease biomarkers in addition to novel molecular pathogenic mechanisms. Ultra high mass resolution MALDI-MSI emerges as a helpful clinical tool in the neurosurgical treatment of pituitary tumors. Therefore, metabolomics appears to be a science with a promising prospect in the sphere of PA, and a starting point in pituitary care.

Enhancement of gama-aminobutyric acid (GABA) and other health-related metabolites in germinated red rice (Oryza sativa L.) by ultrasonication

Red rice (Oryza sativa L.) that has a red (reddish brown) bran layer in de-hulled rice is known to contain rich biofunctional components. Germination is an effective technique to improve the nutritional quality, digestibility, and flavor of de-hulled rice. Ultrasonication, a form of physical stimulation, has been documented as a novel approach to improve the nutritional quality of plant-based food. This study was undertaken to test the use of ultrasound to enhance the nutritional value of red rice. Ultrasonication (5min, 16W/L) was applied to rice during soaking or after 66h germination. Changes of metabolites (amino acids, sugars, and organic acids) in red rice treated by ultrasonication were determined using a GC/MS plant primary metabolomics analysis platform. Differential expressed metabolites were identified through multivariate statistical analysis. Results showed that γ-aminobutyric acid (GABA) and riboflavin (vitamin B₂) in red rice significantly increased after germination for 72h, and then experienced a further increase after treatment by ultrasound at different stages during germination. The metabolomics analysis showed that some plant metabolites, i.e. GABA, O-phosphoethanolamine, and glucose-6-phosphate were significantly increased after the ultrasonic treatment (VIP>1.5) in comparison with the untreated germinated rice. The findings of this study showed that controlled germination with ultrasonic stress is an effective method to enhance GABA and other health-promoted components in de-hulled rice.

Ethical issues on the "synthetic" phosphoethanolamine clinical trial

Notwithstanding its approval by the National Committee for Ethics in Research (Conep) on April 19, 2016, a trial of the so-called "synthetic" phosphoethanolamine (syn-phospho) pill in cancer patients raises ethical concerns. An analysis by a laboratory contracted by the Ministry of Science, Technology and Innovation (MCTI) revealed that syn-phospho contained a great amount of impurities and did not meet standards of pharmaceutical quality required for an investigational drug. Cytotoxicity against human tumor cell lines and in vivo rodent xenograft tumor assays consistently failed to demonstrate a potential anticancer activity of syn-phospho. Preclinical safety studies of syn-phospho were also insufficient to support a trial of this investigational drug in cancer patients. Moreover, the ethical approval decision apparently overlooked two previous findings that suggested a possible enhancement of mammary carcinoma cell proliferation by phosphoethanolamine, and an apparent increase in lung metastases (rat implanted tumor assay) by syn-phospho. The syn-phospho risk-benefit ratio is clearly unfavorable and, thus, this trial in cancer patients does not fulfill a key requirement to make a clinical research ethical. There are also concerns regarding whether the study design is robust enough (scientific validity), and the social value of the trial of syn-phospho in cancer patients is questionable.

Preclinical Development of a Nontoxic Oral Formulation of Monoethanolamine, a Lipid Precursor, for Prostate Cancer Treatment

Purpose: Most currently available chemotherapeutic agents target rampant cell division in cancer cells, thereby affecting rapidly dividing normal cells resulting in toxic side-effects. This nonspecificity necessitates identification of novel cellular pathways that are reprogrammed selectively in cancer cells and can be exploited to develop pharmacologically superior and less toxic therapeutics. Despite growing awareness on dysregulation of lipid metabolism in cancer cells, targeting lipid biosynthesis is still largely uncharted territory. Herein, we report development of a novel nontoxic orally deliverable anticancer formulation of monoethanolamine (Etn) for prostate cancer by targeting the Kennedy pathway of phosphatidylethanolamine (PE) lipid biosynthesis.Experimental Design: We first evaluated gastrointestinal tract stability, drug-drug interaction liability, pharmacokinetic, and toxicokinetic properties of Etn to evaluate its suitability as a nontoxic orally deliverable agent. We next performed in vitro and in vivo experiments to investigate efficacy and mechanism of action.Results: Our data demonstrate that Etn exhibits excellent bioavailability, gastrointestinal tract stability, and no drug-drug interaction liability. Remarkably, orally fed Etn inhibited tumor growth in four weeks by approximately 67% in mice bearing human prostate cancer PC-3 xenografts without any apparent toxicity. Mechanistically, Etn exploits selective overexpression of choline kinase in cancer cells, resulting in accumulation of phosphoethanolamine (PhosE), accompanied by downregulation of HIF-1α that induces metabolic stress culminating into cell death.Conclusions: Our study provides first evidence for the superior anticancer activity of Etn, a simple lipid precursor formulation, whose nontoxicity conforms to FDA-approved standards, compelling its clinical development for prostate cancer management. Clin Cancer Res; 23(14); 3781-93. ©2017 AACR.

A "miracle" cancer drug in the era of social media: A survey of Brazilian oncologists' opinions and experience with phosphoethanolamine

INTRODUCTION

Patients who are treating cancer have often used alternative therapies. In the internet era, information can be broadcasted widely, and this happened with phosphoethanolamine in Brazil, where this substance was claimed by the population to be the "cure for cancer."

METHOD

This is a cross-sectional study developed by the Brazilian Society of Clinical Oncology (SBOC). An objectively structured questionnaire was sent by e-mail and SMS to active MDs members of the SBOC. Descriptive statistics was used to evaluate the data. Statistical significance between the variables was tested by Pearson's Chi-squared test (p<0.05 was considered significance).

RESULTS

The survey was sent to 1,072 oncologists, and 398 (37.1%) answered at least part of it. One hundred and fifteen (28.9%) had followed patients who had used phosphoethanolamine. Among these, 14 (12.2%) observed adverse events and four (3.5%) attributed clinical benefit to the substance. Most of the oncologists (n=331; 83.2%) believe that it should only be used as part of a clinical trial protocol. Most physicians did not recommend this drug to their patients (n=311; 78.1%). Oncologists in Southeast, South and Midwest Brazil were more likely to have patients taking the drug compared to the Northern and Northeastern regions.

CONCLUSION

This is the first survey to assess the opinion and experience of oncologists about this alternative therapy. Most oncologists in Brazil do not believe that synthetic phosphoethanolamine is active in cancer treatment, do not recommend its use without proper evaluation, and state that it should only be available to patients in the context of clinical trials.

Targeting Phospholipid Metabolism in Cancer

All cancers tested so far display abnormal choline and ethanolamine phospholipid metabolism, which has been detected with numerous magnetic resonance spectroscopy (MRS) approaches in cells, animal models of cancer, as well as the tumors of cancer patients. Since the discovery of this metabolic hallmark of cancer, many studies have been performed to elucidate the molecular origins of deregulated choline metabolism, to identify targets for cancer treatment, and to develop MRS approaches that detect choline and ethanolamine compounds for clinical use in diagnosis and treatment monitoring. Several enzymes in choline, and recently also ethanolamine, phospholipid metabolism have been identified, and their evaluation has shown that they are involved in carcinogenesis and tumor progression. Several already established enzymes as well as a number of emerging enzymes in phospholipid metabolism can be used as treatment targets for anticancer therapy, either alone or in combination with other chemotherapeutic approaches. This review summarizes the current knowledge of established and relatively novel targets in phospholipid metabolism of cancer, covering choline kinase α, phosphatidylcholine-specific phospholipase D1, phosphatidylcholine-specific phospholipase C, sphingomyelinases, choline transporters, glycerophosphodiesterases, phosphatidylethanolamine N-methyltransferase, and ethanolamine kinase. These enzymes are discussed in terms of their roles in oncogenic transformation, tumor progression, and crucial cancer cell properties such as fast proliferation, migration, and invasion. Their potential as treatment targets are evaluated based on the current literature.

Phosphoethanolamine and the danger of unproven drugs

The use of unproven forms of therapy in cancer treatment is very common. In Brazil, the distribution by researchers to patients of an investigational agent called phophoethanolamine (PHOS) has led to a widely publicized scientific scandal. PHOS is a precursor to components of the cell membrane, with some published pre-clinical studies suggesting cytotoxic activity in cancer cells. The willingness of courts and of legislators to guarantee access to PHOS in spite of the lack of any clinical data and against the recommendations of scientific and medical organisations underscores the risks that unproven agents pose to regulatory authorities, health care systems and patients, and bears resemblance to other cases such as the controversy surrounding the approval of zidovudine for AIDS treatment by the FDA.

Potential antitumor activity of novel DODAC/PHO-S liposomes

In recent studies, we showed that synthetic phosphoethanolamine (PHO-S) has a great potential for inducing cell death in several tumor cell lines without damage to normal cells. However, its cytotoxic effect and selectivity against tumor cells could increase with encapsulation in cationic liposomes, such as dioctadecyldimethylammonium chloride (DODAC), due to electrostatic interactions between these liposomes and tumor cell membranes. Our aim was to use cationic liposomes to deliver PHO-S and to furthermore maximize the therapeutic effect of this compound. DODAC liposomes containing PHO-S (DODAC/PHO-S), at concentrations of 0.3-2.0 mM, prepared by ultrasonication, were analyzed by scanning electron microscopy (SEM) and dynamic light scattering. The cytotoxic effect of DODAC/PHO-S on B16F10 cells, Hepa1c1c7 cells, and human umbilical vein endothelial cells (HUVECs) was assessed by MTT assay. Cell cycle phases of B16F10 cells were analyzed by flow cytometry and the morphological changes by SEM, after treatment. The liposomes were spherical and polydisperse in solution. The liposomes were stable, presenting an average of ∼ 50% of PHO-S encapsulation, with a small reduction after 40 days. DODAC demonstrated efficient PHO-S delivery, with the lowest values of IC50% (concentration that inhibits 50% of the growth of cells) for tumor cells, compared with PHO-S alone, with an IC50% value of 0.8 mM for B16F10 cells and 0.2 mM for Hepa1c1c7 cells, and without significant effects on endothelial cells. The Hepa1c1c7 cells showed greater sensitivity to the DODAC/PHO-S formulation when compared to B16F10 cells and HUVECs. The use of DODAC/PHO-S on B16F10 cells induced G2/M-phase cell cycle arrest, with the proportion significantly greater than that treated with PHO-S alone. The morphological analysis of B16F10 cells by SEM showed changes such as "bleb" formation, cell detachment, cytoplasmic retraction, and apoptotic bodies after DODAC/PHO-S treatment. Cationic liposomal formulation for PHO-S delivery promoted cytotoxicity more selectively and effectively against B16F10 and Hepa1c1c7 cells. Thus, the DODAC/PHO-S liposomal formulation presents great potential for preclinical studies.

Anti-angiogenic and anti-metastatic activity of synthetic phosphoethanolamine

BACKGROUND

Renal cell carcinoma (RCC) is the most common type of kidney cancer, and represents the third most common urological malignancy. Despite the advent of targeted therapies for RCC and the improvement of the lifespan of patients, its cost-effectiveness restricted the therapeutic efficacy. In a recent report, we showed that synthetic phosphoethanolamine (Pho-s) has a broad antitumor activity on a variety of tumor cells and showed potent inhibitor effects on tumor progress in vivo.

METHODOLOGY/PRINCIPAL FINDINGS

We show that murine renal carcinoma (Renca) is more sensitive to Pho-s when compared to normal immortalized rat proximal tubule cells (IRPTC) and human umbilical vein endothelial cells (HUVEC). In vitro anti-angiogenic activity assays show that Pho-s inhibits endothelial cell proliferation, migration and tube formation. In addition, Pho-s has anti-proliferative effects on HUVEC by inducing a cell cycle arrest at the G2/M phase. It causes a decrease in cyclin D1 mRNA, VEGFR1 gene transcription and VEGFR1 receptor expression. Pho-s also induces nuclear fragmentation and affects the organization of the cytoskeleton through the disruption of actin filaments. Additionally, Pho-s induces apoptosis through the mitochondrial pathway. The putative therapeutic potential of Pho-s was validated in a renal carcinoma model, on which our remarkable in vivo results show that Pho-s potentially inhibits lung metastasis in nude mice, with a superior efficacy when compared to Sunitinib.

CONCLUSIONS/SIGNIFICANCE

Taken together, our findings provide evidence that Pho-s is a compound that potently inhibits lung metastasis, suggesting that it is a promising novel candidate drug for future developments.

Synthetic phosphoethanolamine induces cell cycle arrest and apoptosis in human breast cancer MCF-7 cells through the mitochondrial pathway

Phosphoethanolamine (Pho-s) is a compound involved in phospholipid turnover, acting as a substrate for many phospholipids of the cell membranes. In a recent study, we showed that Pho-s has antitumor effect in the several tumor cells. In this study we evaluated the antitumor activity of synthetic Pho-s on MCF-7 breast cancer cells. Here we demonstrate that Pho-s is cytotoxic to MCF-7 cells in a dose-dependent manner, while it is cytotoxic to MCF10 only at higher concentrations. In addition, Pho-s induces a disruption in mitochondrial membrane potential (Δψm). Furthermore, Pho-s induces mitochondria aggregates in the cytoplasm and DNA fragmentation of MCF-7 cells visualized by confocal microscopy. In agreement with the reduction on Δψm, we showed that Pho-s induces apoptosis followed by an increase in cytochrome c expression and capase-3-like activity in MCF-7 cells. Our results demonstrate that Pho-s induces a cell cycle arrest in the G1 phase through an inhibition of cyclin D1 and stimulates p53. An additional highlight of this study is the finding that Pho-s inhibits Bcl-2, inducing apoptosis through the mitochondrial pathway. Taken together, these results show that Pho-s is a promising compound in the fight against cancer.