LGR5 as a Therapeutic Target of Antibody-Functionalized Biomimetic Magnetoliposomes for Colon Cancer Therapy.

Purpose: The lack of specificity of conventional chemotherapy is one of the main difficulties to be solved in cancer therapy. Biomimetic magnetoliposomes are successful chemotherapy controlled-release systems, hyperthermia, and active targeting agents by functionalization of their surface with monoclonal antibodies. The membrane receptor Leucine-rich repeat-containing G-protein coupled receptor 5 (LGR5) stands out as colorectal cancer (CRC) biomarker and appears to be related to treatment resistance and the development of metastasis. The aim of this study was to assess the effectiveness and safety of LGR5-targeted biomimetic magnetoliposomes loaded with oxaliplatin (OXA) or 5-fluorouracil (5-FU) in the selective treatment of CRC and their possible application in hyperthermia. Methods: Synthesis, characterization and determination of heating capacity of magnetoliposomes transporting OXA or 5-FU (with and without LGR5 functionalization) were conducted. In vitro antitumoral activity was assayed in multiple colorectal cell lines at different times of exposition. In addition to this, cell internalization was studied by Prussian Blue staining, flow cytometry and fluorescence microscopy. In vivo acute toxicity of magnetoliposomes was performed to evaluate iron-related toxicity. Results: OXA and 5-FU loaded magnetoliposomes functionalized with LGR5 antibody showed higher cellular uptake than non-targeted nanoformulation with a reduction of the percentage of proliferation in colon cancer cell lines up to 3.2-fold of the IC50 value compared to that of free drug. The differences between non-targeted and targeted nanoformulations were more evident after short exposure times (4 and 8 hours). Interestingly, assays in the MC38 transduced cells with reduced LGR5 expression (MC38-L(-)), showed lower cell internalization of LGR5-targeted magnetoliposomes compared to non-transduced MC38 cell line. In addition, magnetoliposomes showed an in vitro favorable heating response under magnetic excitation and great iron-related biocompatibility data in vivo. Conclusion: Drug-loaded magnetoliposomes functionalized with anti-LGR5 antibodies could be a promising CRC treatment strategy for LGR5+ targeted chemotherapy, magnetic hyperthermia, and both in combination.

Active Biomolecules from Vegetable Extracts with Antitumoral Activity against Pancreas Cancer: A Systematic Review (2011-2021).

The emergence of resistance to pancreatic cancer (PC) current treatment requires the development of new therapeutic strategies. In this context, bioactive molecules from plant extracts have shown excellent properties to improve classical therapy against this type of tumor. This systematic review aims to collect all the in vitro studies related to the antiproliferative activity of isolated plant molecules that support their applicability in PC. A total of 620 articles published in the last 10 years were identified, although only 28 were finally included to meet the inclusion criteria. Our results reflect the most important biomolecules from natural compounds that induce cell death in PC and their essential mechanism of cell death, including apoptosis, pathways activated by the KRAS mutation and cycle cell arrest, among others. These in vitro studies provide an excellent molecule guide showing applications against PC and that should be tested in vivo and in clinical trials to determine their usefulness to reduce PC incidence and to improve the prognosis of these patients. However, natural compounds are isolated in small amounts, which prevents comprehensive drug screening, being necessary the role of organic synthesis for the total synthesis of natural compounds or for the synthesis of their simplified and bioactive analogs.

Bioavailability and biotransformation of linolenic acid from basil seed oil as a novel source of omega-3 fatty acids tested on a rat experimental model.

Basil is an aromatic herb with a high concentration of bioactive compounds. The oil extracted from its seeds is a good source of α-linolenic acid (ALA) and also provides substantial amounts of linoleic acid (LA). This study aimed to test the bioavailability of the oil derived from basil seeds and its effects on different physiological parameters using 7-15% dietary inclusion levels. Furthermore, the assimilation of LA and ALA and their transformation in long-chain polyunsaturated fatty acids (LC-PUFAs) have been studied. Digestive utilization of total fat from basil seed oil (BSO) was high and similar to that of olive oil used as a control. Consumption of BSO resulted in increased LA and ALA levels of the plasma, liver, and erythrocyte membrane. In addition, the transformation of LA to arachidonic acid (ARA) was decreased by the high dietary intake of ALA which redirected the pathway of the Δ-6 desaturase enzyme towards the transformation of ALA into eicosapentaenoic acid (EPA). No alterations of hematological and plasma biochemical parameters were found for the 7 and 10% dietary inclusion levels of BSO, whereas a decrease in the platelet count and an increase in total- and HDL-cholesterol as well as plasma alkaline phosphatase (ALP) were found for a 15% BSO dose. In conclusion, BSO is a good source of ALA to be transformed into EPA and decrease the precursor of the pro-inflammatory molecule ARA. This effect on the levels of EPA in different tissues offers potential for its use as a dietary supplement, novel functional food, or a constituent of nutraceutical formulations to treat different pathologies.

Preventive effects of Brassicaceae family for colon cancer prevention: A focus on in vitro studies.

The emergence of adverse effects and resistance to colorectal cancer (CRC) current therapies calls for the development of new strategies aimed at both preventing and treating. In this context, functional extracts from Brassicaceae family contains abundant bioactive compounds directly related to a positive effect on human health including cancer. The main objective of this systematic review is to compile all recent studies that analyzed the in vitro antiproliferative activity of functional extracts or isolated molecules from the Brassicaceae family against CRC. A total of 711 articles published between January 2011 and May 2021 were identified. Of them, 68 met our inclusion criteria. Different standardized protocols using variable parts of plants of the Brassicaceae family resulted in diverse bioactive extracts and/or compounds. Most of them were related to isothiocyanates, which showed significant antitumor activity against CRC. These in vitro studies provide an excellent guide to direct research on the applications of plants of the Brassicaceae family to the prevention of this type of tumor. The extracts and molecules with demonstrated activity against CRC should be tested in vivo and in clinical trials to determine their usefulness in the prevention of this cancer to reduce its global incidence.

Antioxidant and antiproliferative potential of ethanolic extracts from Moringa oleifera, Tropaeolum tuberosum and Annona cherimola in colorrectal cancer cells.

Moringa oleifera, Tropaeolum tuberosum and Annona cherimola are medicinal plants traditionally used in Ecuador. However, their therapeutic properties are not completely known. We analyzed chromatographically ethanolic extracts of the seeds of M. oleifera, A. cherimola and the tubers of T. tuberosum; all presented a high content of polyphenols. The extract of A. cherimola showed the highest antioxidant activity and M. oleifera had the highest capacity to enhance the activity of detoxifying enzymes such as glutathione S-transferase and quinone oxidoreductase. The antitumor effect of these extracts was evaluated in vitro with colorectal cancer (CRC) cell lines T84, HCT-15, SW480 and HT-29, as well as with cancer stem cells (CSCs). A. cherimola and M. oleifera extracts presented the lowest IC50 in T-84 and HCT-15 (resistant) cells, respectively, as well as the highest level of inhibition of proliferation in multicellular tumor spheroids of HCT-15 cells. The inhibitory effect on CSCs is noteworthy because in vivo, these cells are often responsible for cancer recurrences and resistance to chemotherapy. Moreover, all extracts showed a synergistic activity with 5-Fu. The antiproliferative mechanism of the extracts was related to overexpression of caspases 9, 8 and 3 and increased production of reactive oxygen species. In addition, we observed cell death by autophagy in M. oleifera and T. tuberosum extracts. Therefore, these ethanolic extracts are excellent candidates for future molecular analysis of the presence of bioactive compounds and in vivo studies which could improve colon cancer therapy.

Antitumor Effect of the Ethanolic Extract from Seeds of Euphorbia lathyris in Colorectal Cancer.

The seeds of Euphorbia lathyris have been used in traditional medicine to treat various medical conditions. However, neither all of their active biocompounds nor the molecular mechanisms underlying their therapeutic effects have been described. A new ethanolic extract of defatted flour from mature seeds of Euphorbia lathyris showed a high total polyphenol content and significant antioxidant activity. Chromatographic analysis showed that esculetin, euphorbetin, gaultherin, and kaempferol-3-rutinoside were the most abundant polyphenolic bioactive compounds. Antiproliferative assays showed a high and selective antitumor activity against colon cancer cell lines (T84 and HCT-15). In addition, a significant antiproliferative activity against glioblastoma multiforme cells was also demonstrated. Its mechanism of action to induce cell death was mediated by the overexpression of caspases 9, 3, and 8, and by activation of autophagy. Interestingly, a reduction in the migration capacity of colon cancer cells and a significant antiangiogenic effect on human umbilical vein endothelial cells were also demonstrated. Finally, the extract significantly reduced the subpopulations of cancer stem cells. This extract could be the basis to develop new therapeutic strategies for the treatment of colon cancer, although further experiments will be necessary to determine its in vivo effects.

Identification of PARP-1 in cancer stem cells of gastrointestinal cancers: A preliminary study.

Advanced-stage gastrointestinal tumors have high mortality due to chemotherapy limitations. One of the causes of treatment failure is the presence of cancer stem cells (CSCs), which show resistance mechanisms against DNA damage, such as poly (adenosine diphosphate-ribose) polymerase 1 (PARP-1). However, little is known about the relevance of PARP-1 in these tumor cells. Our purpose is to analyze the expression of PARP-1 in cancer cells and CSCs from gastrointestinal tumors, its relationship with the DNA damage repair process and its modulation by cytotoxic and PARP-1 inhibitors. We used pancreatic, liver and colon cancer cell lines and isolated CSCs using Aldefluor technology to analyze PARP-1 expression. In addition, we examined the effect of classic cytotoxic drugs (Doxorubicin, Gemcitabine, Irinotecan and 5-Fluorouracil) and a PARP-1 inhibitor (Olaparib) in cultured cells and 3D tumorspheres. We demonstrated that PARP-1 is highly expressed in pancreatic, liver and colon tumor cells and that this expression was significantly higher in cell populations with CSC characteristics. In addition, Doxorubicin and Gemcitabine increased their cytotoxic effect when administered simultaneously with Olaparib, decreasing the formation of 3D tumorspheres. Our findings suggest that PARP-1 is a common and relevant resistance mechanism in CSCs from gastrointestinal tumors and that the use of PARP-1 inhibitors may be an adjuvant therapy to increase apoptosis in this type of cells which are responsible to cancer recurrence and metastasis.

Latest in Vitro and in Vivo Assay, Clinical Trials and Patents in Cancer Treatment using Curcumin: A Literature Review.

Curcumin, the main active compound of the curcuma root, shows antioxidant, anti-inflammatory, and antitumor properties which have been demonstrated in preclinical and clinical trials. Its antitumor activity is mediated by its ability to act directly on the tumor cell, activating apoptosis pathways and indirectly inhibiting the process of inflammation, angiogenesis, and metastasis in the tumor microenvironment. In addition, it has a preventive activity such as radio and/or chemosensitizer. These effects have been evident in in vitro assays but have also been corroborated in patient trials either through the isolated use of curcumin or through its association with other agents. Moreover, curcumin has demonstrated a low induction of side effects. Numerous patents have been developed in connection with the administration and use of curcumin against different types of cancer. All this justifies the interest for the development of new laboratory studies and especially of clinical trials to validate this compound as a dietary supplement in both the healthy and the oncological population. The present review aims to address the most recent in vitro investigations and the latest clinical trials and patents related to the curcumin agent to provide an up-to-date overview of the latest advances in relation to its antitumor effect.

Nano-engineering of biomedical prednisolone liposomes: evaluation of the cytotoxic effect on human colon carcinoma cell lines.

OBJECTIVES: Liposomes have attracted the attention of researchers due to their potential to act as drug delivery systems for cancer treatment. The present investigation aimed to develop liposomes loaded with prednisolone base and the evaluation of the antiproliferative effect on human colon carcinoma cell lines. METHODS: Liposomes were elaborated by following a reproducible thin film hydration technique. The physicochemical characterization of liposomes included photon correlation spectroscopy, microscopy analysis, Fourier transform infrared spectroscopy, rheological behaviour and electrophoresis. On the basis of these data and drug loading values, the best formulation was selected. Stability and drug release properties were also tested. KEY FINDINGS: Resulting liposomes exhibited optimal physicochemical and stability properties, an excellent haemocompatibility and direct antiproliferative effect on human colon carcinoma T-84 cell lines. CONCLUSIONS: This study shows direct antitumour effect of prednisolone liposomal formulation, which opens the door for liposomal glucocorticoids as novel antitumour agents.

Nanoemulsion Strategy for Ursolic and Oleanic Acids Isolates from Plumeria Obtusa Improves Antioxidant and Cytotoxic Activity in Melanoma Cells.

BACKGROUND: Triterpenoids are an important class of natural bioactive products present in many medicinal plants. OBJECTIVE: The aim of present study is to investigate the antioxidant and anticarcinogenic potential of Oleanolic Acid (OA) and Ursolic Acid (UA) on B16 murine melanoma cell line isolated from Plumeria obtusa, free and loaded in a nanoemulsion (NEm) system. METHODS: The nanoemulsion was characterized by dynamic light scattering, transmission electron microscopy. The viscosity was also evaluated. The antioxidant activity was determined by the reduction of 2,2-diphenyl-2- picrylhydrazyl (DPPH) free radical. In vitro proliferation studies were determined using the sulforhodamine-B method. RESULTS: OA/UA natural mixture exhibited high percentage of inhibition of DPPH (86.06% and 85.12%, with and without irradiation). Percentages of inhibition higher than 85% in samples with and without ultraviolet irradiation were recorded when loaded in the NEm system. The natural mixture incorporated into the NEm showed cytotoxic activity from 2.9 µM, whereas the free compounds from 17.4 µM. CONCLUSION: We conclude that these pentacyclic triterpenes loaded in a NEm system could be considered as a new potential tool for further investigation as anticancer agents.

Magnetic solid lipid nanoparticles in hyperthermia against colon cancer.

A reproducible double emulsion/solvent evaporation procedure is developed to formulate magnetic solid lipid nanoparticles (average size≈180 nm) made of iron oxide cores embedded within a glyceryl trimyristate solid matrix. The physicochemical characterization of the nanocomposites ascertained the efficacy of the preparation conditions in their production, i.e. surface properties (electrokinetic and thermodynamic data) were almost indistinguishable from those of the solid lipid nanomatrix, while electron microscopy characterizations and X-ray diffraction patterns confirmed the satisfactory coverage of the magnetite nuclei. Hemocompatibility of the particles was established in vitro. Hysteresis cycle determinations defined the appropriate magnetic responsiveness of the nanocomposites, and their heating characteristics were investigated in a high frequency alternating gradient of magnetic field: a constant maximum temperature of 46 °C was obtained within 40 min. Finally, in vitro tests performed on human HT29 colon adenocarcinoma cells demonstrated a promising decrease in cell viability after treatment with the nanocomposites and exposure to that alternating electromagnetic field. To the best of our knowledge, this is the first time that such type of nanoformulation with very promising hyperthermia characteristics has been developed for therapeutic aims.

Nano-engineering of 5-fluorouracil-loaded magnetoliposomes for combined hyperthermia and chemotherapy against colon cancer.

The present investigation aimed to develop magnetoliposome nanoparticles loaded with 5-fluorouracil by following a reproducible thin film hydration technique. The physicochemical characterization (including electron microscopy analysis, dynamic light scattering, infrared spectrometry, X-ray diffractometry, electrophoresis, and surface thermodynamics) suggested that superparamagnetic magnetite nuclei were successfully embedded into a multilamellar lipid vesicle. Magnetic responsiveness of these nanocomposites was quantitatively analyzed by determining the hysteresis cycle and qualitatively confirmed by microscopic visualizations. A high frequency alternating electromagnetic field was further used to define their heating properties. The absence of cytotoxicity in human colon fibroblast CCD-18 and in human colon carcinoma T-84 cell lines and excellent hemocompatibility of these core/shell particles were demonstrated. Additionally, 5-fluorouracil incorporation was investigated by two procedures: (i) entrapment into the nanoparticulate matrix and (ii) surface deposition onto already formed magnetoliposome particles. The former method reported greater drug loading values and a sustained release profile. Interestingly, 5-fluorouracil release was also triggered by the heating properties of the nanoparticles (hyperthermia-triggered drug release). Hence, we put forward that magnetoliposome particles hold important properties, that is, magnetically targeted delivery, hyperthermia inducing capability, high 5-fluorouracil loading capability, and hyperthermia-triggered burst drug release, suggestive of their potential for a combined antitumor therapy against colon cancer.

Antitumor properties of natural compounds and related molecules.

Cancer is the main cause of death in developing countries. Its development requires multiple steps in which the occurrence of certain events determines the state transition from a normal to a tumor cell. These events are related to the loss of mechanisms that control various biological processes, which results from the accumulation of genetic alterations, including mutations, chromosomal rearrangements, and variations in gene copy number, as well as from epigenetic alterations. In general, chemotherapeutic agents used for toxicity treatments have shown limited antitumor activity, with a high recurrence rate. This has prompted major research efforts to identify novel effective and selective anti-tumor compounds. In this article, we review recent patents that protect the antitumor properties of natural compounds and related molecules derived from plants, animals, or microorganisms. We consider their structure, mechanism of action, molecular targets and, in some cases, the clinical trial phase reached. We also report on various natural agents that appear to prevent cancer development.

E phage gene transfection associated to chemotherapeutic agents increases apoptosis in lung and colon cancer cells.

The limited ability of conventional therapies to achieve the long-term survival of metastatic lung and colon cancer patients suggests the need for new treatment options. In this respect, genes encoding cytotoxic proteins have been proposed as a new strategy to enhance the activity of drugs, and combined therapies involving such genes and classical antitumoral drugs have been studied intensively. The E gene from phiX174 encodes a membrane protein with a toxic domain that leads to a decrease in tumour cell growth rates. Therefore, in order to improve the anti-tumour effects of currently used chemotherapeutic drugs on cancer cells, we investigated the association of the E suicide gene with these antineoplastic drugs. The E gene has antitumoral effects in both lung and colon cancer cells. In addition, expression of this gene induces ultrastructural changes in lung cancer transfected cells (A-549), although the significance of these changes remains unknown. The effect of combined therapy (gene and cytotoxic therapy) enhances the inhibition of tumour cell proliferation in comparison to single treatments. Indeed, our in vitro results indicate that an experimental therapeutic strategy based on this combination of E gene therapy and cytotoxic drugs may result in a new treatment strategy for patients with advanced lung and colon cancer.