ABSTRACT
BACKGROUND: Gliomas are the most malignant tumors of the central nervous system. One of the factors in their high drug resistance is avoiding programmed death (PCD) induction. This is related to the overexpression of intracellular survival pathways: PI3K-Akt/PKB-mTOR and Ras-Raf-MEK-ERK. Apoptosis and autophagy are co-existing processes due to the interactions between Bcl-2 and beclin-1 proteins. Their complex may be a molecular "toggle-switch" between PCD types. The aim of this research was to investigate the role of Bcl-2:beclin-1 complex in glioma cell elimination through the combined action of LY294002 and sorafenib. METHODS: Drug cytotoxicity was estimated with an MTT test. The type of cell death was evaluated using variant microscopy techniques (fluorochrome staining, immunocytochemistry, and transmission electron microscopy), as well as the Bcl-2:beclin-1 complex formation and protein localization. Molecular analysis of PCD indicators was conducted through immunoblotting, immunoprecipitation, and ELISA testing. SiRNA was used to block Bcl-2 and beclin-1 expression. RESULTS: The results showed the inhibitors used in simultaneous application resulted in Bcl-2:beclin-1 complex formation and apoptosis becoming dominant. This was accompanied by changes in the location of the tested proteins. CONCLUSIONS: "Switching" between apoptosis and autophagy using PI3K and Raf inhibitors with Bcl-2:beclin-1 complex formation opens new therapeutic perspectives against gliomas.
Subject(s)
Glioma , Phosphatidylinositol 3-Kinases , Sorafenib , Humans , Apoptosis , Autophagy , Beclin-1 , Glioma/drug therapy , Glioma/pathology , Phosphatidylinositol 3-Kinases/metabolism , Sorafenib/pharmacology , Sorafenib/therapeutic useABSTRACT
Human gamma-delta (γδ) T cells are a heterogeneous cell population that bridges the gap between innate and acquired immunity. They are involved in a variety of immunological processes, including tumor escape mechanisms. However, by being prolific cytokine producers, these lymphocytes also participate in antitumor cytotoxicity. Which one of the two possibilities takes place depends on the tumor microenvironment (TME) and the subpopulation of γδ T lymphocytes. The aim of this paper is to summarize existing knowledge about the phenotype and dual role of γδ T cells in cancers, including ovarian cancer (OC). OC is the third most common gynecological cancer and the most lethal gynecological malignancy. Anticancer immunity in OC is modulated by the TME, including by immunosuppressive cells, cytokines, and soluble factors. Immune cells are exposed in the TME to many signals that determine their immunophenotype and can manipulate their functions. The significance of γδ T cells in the pathophysiology of OC is enigmatic and remains to be investigated.
Subject(s)
Neoplasms , T-Lymphocytes , Humans , Receptors, Antigen, T-Cell, gamma-delta , Adaptive Immunity , Tumor Microenvironment , Tumor Escape , Cytokines , Neoplasms/pathologyABSTRACT
Obesity is a civilization disease associated with an increased risk of developing cardiovascular diseases, diabetes, and some malignancies. The results concerning the relationship between obesity and epithelial ovarian cancer (EOC) are inconclusive. The higher incidence of neoplasms in obese subjects has led to the development of the adipokine hypothesis. Omental adipocyte cells interact with cancer cells, promoting their migration and metastasis via the secretion of adipokines, growth factors, and hormones. One of the adipokines is resistin. It was shown in vitro that resistin stimulates the growth and differentiation of ovarian cancer cells. Moreover, it increases the level of angiogenesis factors, e.g., matrix metalloproteinase 2 (MMP-2) and vascular epithelial growth factor (VEGF). Additionally, resistin induces epithelial-mesenchymal transition (EMT) and stemness in EOC cell lines. A positive correlation has been shown between a higher level of resistin expression and the stage of histological differentiation of EOC or the occurrence of lymph node metastases. In addition, the overexpression of resistin has been found to act as an independent factor determining disease-free survival as well as overall survival in EOC patients. Growing evidence supports the finding that resistin plays an important role in some mechanisms leading to the progression of EOC, though this issue still requires further research.
ABSTRACT
BACKGROUND: Gliomas are highly malignant brain tumours with high resistance to chemotherapy. Therefore, investigations of new therapeutic molecules with high anti-glioma activity are of great importance. OBJECTIVES: In this work, biocatalytic esterification of terpene alcohols with proven anti-cancer activity was performed to enhance their potency to induce cell death in human glioblastoma multiforme T98G and anaplastic astrocytoma MOGGCCM cell lines in vitro. METHODS AND RESULTS: We used primary terpene alcohols and carboxylic acids with a length of two to nine carbon atoms. The structure of the alcohols had an influence on the esterification efficiency, which decreased in the following order: monocyclic > linear > bicyclic. Terpene alcohols and their esters only induced apoptotic cell death, which is highly desirable from a therapeutic point of view, but did not induce autophagy and necrosis. The esterification of perillyl alcohol with butyric acid caused a 4-fold increase in cell death induction in the T98G line. Citronellol valerate, caprylate, and pelargonate and myrtenol butyrate, caprylate and pelargonate also showed higher activity than their alcohol precursors. CONCLUSION: We have herein shown that esterification of natural alcohols by biocatalysis can be used for improving the activity of other compounds investigated for their anti-glioma activity.
Subject(s)
Astrocytoma , Glioblastoma , Glioma , Astrocytoma/drug therapy , Biocatalysis , Esters/therapeutic use , Glioblastoma/drug therapy , Glioma/drug therapy , Glioma/metabolism , Humans , Terpenes/pharmacology , Terpenes/therapeutic useABSTRACT
The aim of the study was to investigate the anticancer potential of LY294002 (PI3K inhibitor) and temozolomide using glioblastoma multiforme (T98G) and anaplastic astrocytoma (MOGGCCM) cells. Apoptosis, autophagy, necrosis, and granules in the cytoplasm were identified microscopically (fluorescence and electron microscopes). The mitochondrial membrane potential was studied by flow cytometry. The activity of caspases 3, 8, and 9 and Akt was evaluated fluorometrically, while the expression of Beclin 1, PI3K, Akt, mTOR, caspase 12, and Hsp27 was determined by immunoblotting. SiRNA was used to block Hsp27 and PI3K expression. Cell migration and localization of Hsp27 were tested with the wound healing assay and immunocytochemistry, respectively. LY294002 effectively diminished the migratory potential and increased programmed death of T98G and MOGGCCM. Autophagy was dominant in MOGGCCM, while apoptosis was dominant in T98G. LY294002 with temozolomide did not potentiate cell death but redirected autophagy toward apoptosis, which was correlated with ER stress. A similar effect was observed after blocking PI3K expression with siRNA. Transfection with Hsp27 siRNA significantly increased apoptosis related to ER stress. Our results indicate that inhibition of the PI3K/Akt/mTOR pathway sensitizes glioma cells to apoptosis upon temozolomide treatment, which was correlated with ER stress. Hsp27 increases the resistance of glioma cells to cell death upon temozolomide treatment.
Subject(s)
Biomarkers, Tumor/metabolism , Chromones/pharmacology , Drug Resistance, Neoplasm/genetics , Gene Expression Regulation, Neoplastic , Glioblastoma/drug therapy , Morpholines/pharmacology , Phosphatidylinositol 3-Kinases/metabolism , Temozolomide/pharmacology , Antineoplastic Agents, Alkylating/pharmacology , Apoptosis , Biomarkers, Tumor/genetics , Cell Proliferation , Enzyme Inhibitors/pharmacology , Glioblastoma/genetics , Glioblastoma/metabolism , Glioblastoma/pathology , Humans , Membrane Potential, Mitochondrial , Necrosis , Phosphatidylinositol 3-Kinases/chemistry , Phosphatidylinositol 3-Kinases/genetics , Tumor Cells, CulturedABSTRACT
AIM: The anti-glioma effect of lensoside Aß alone and in combination with sorafenib (pro-survival Raf kinase inhibitor) was evaluated for the first time in terms of programmed cell death induction in anaplastic astrocytoma and glioblastoma multiforme cell lines as an experimental model. Apoptosis, autophagy, and necrosis were identified microscopically (fluorescence and scanning microscopes) and confirmed by flow cytometry (mitochondrial membrane potential MMP and cell death). The expression of apoptotic (caspase 3) and autophagic markers (beclin 1) as well as Raf kinase were estimated by immunoblotting. The FTIR method was used to determine the interaction of the studied drugs with lipid and protein groups within cells, while the modes of drug action within the cells were assessed with the FLIM technique. RESULTS: Lensoside Aß itself does not exhibit anti-glioma activity but significantly enhances the anti-cancer potential of sorafenib, initiating mainly apoptosis of up to 90% of cells. It was correlated with an increased level of active caspase 3, a reduced MMP value, and a lower level of Raf kinase. The interaction with membrane structures led to morphological changes typical of programmed death. CONCLUSIONS: Our results indicate that lensoside Aß plays an important role as an adjuvant in chemotherapy with sorafenib and may be a potential candidate in anti-glioma combination therapy.
ABSTRACT
Coumarins, which occur naturally in the plant kingdom, are diverse class of secondary metabolites. With their antiproliferative, chemopreventive and antiangiogenetic properties, they can be used in the treatment of cancer. Their therapeutic potential depends on the type and location of the attachment of substituents to the ring. Therefore, the aim of our study was to investigate the effect of simple coumarins (osthole, umbelliferone, esculin, and 4-hydroxycoumarin) combined with sorafenib (specific inhibitor of Raf (Rapidly Accelerated Fibrosarcoma) kinase) in programmed death induction in human glioblastoma multiforme (T98G) and anaplastic astrocytoma (MOGGCCM) cells lines. Osthole and umbelliferone were isolated from fruits: Mutellina purpurea L. and Heracleum leskowii L., respectively, while esculin and 4-hydroxycoumarin were purchased from Sigma Aldrich (St. Louis, MO, USA). Apoptosis, autophagy and necrosis were identified microscopically after straining with specific fluorochromes. The level of caspase 3, Beclin 1, PI3K (Phosphoinositide 3-kinase), and Raf kinases were estimated by immunoblotting. Transfection with specific siRNA (small interfering RNA) was used to block Bcl-2 (B-cell lymphoma 2), Raf, and PI3K expression. Cell migration was tested with the wound healing assay. The present study has shown that all the coumarins eliminated the MOGGCCM and T98G tumor cells mainly via apoptosis and, to a lesser extent, via autophagy. Osthole, which has an isoprenyl moiety, was shown to be the most effective compound. Sorafenib did not change the proapoptotic activity of this coumarin; however, it reduced the level of autophagy. At the molecular level, the induction of apoptosis was associated with a decrease in the expression of PI3K and Raf kinases, whereas an increase in the level of Beclin 1 was observed in the case of autophagy. Inhibition of the expression of this protein by specific siRNA eliminated autophagy. Moreover, the blocking of the expression of Bcl-2 and PI3K significantly increased the level of apoptosis. Osthole and sorafenib successfully inhibited the migration of the MOGGCCM and T98G cells.
Subject(s)
Antineoplastic Agents, Phytogenic/pharmacology , Coumarins/pharmacology , Glioblastoma/drug therapy , Magnoliopsida/chemistry , Plant Extracts/pharmacology , Sorafenib/pharmacology , 4-Hydroxycoumarins/pharmacology , Antineoplastic Agents, Phytogenic/isolation & purification , Apoptosis/drug effects , Autophagy/drug effects , Beclin-1/genetics , Beclin-1/metabolism , Caspase 3/metabolism , Cell Line, Tumor , Cell Proliferation/drug effects , Esculin/pharmacology , Gene Expression Regulation/drug effects , Humans , Necrosis/drug therapy , Phosphatidylinositol 3-Kinases/genetics , Phosphatidylinositol 3-Kinases/metabolism , Proto-Oncogene Proteins c-bcl-2/genetics , Proto-Oncogene Proteins c-bcl-2/metabolism , RNA, Small Interfering/metabolism , Umbelliferones/pharmacology , raf Kinases/metabolismABSTRACT
In the recent years, coumarin bioactive compounds have been identified to posess anticancer properties. Therefore, the aim of the present study was to investigate for the first time the efficacy of osthole, umbelliferone, esculin, and 4-hydroxycoumarin, alone and in combination with Temozolomide, in the elimination of deadly brain tumors, anaplastic astrocytoma (AA) and glioblastoma multiforme (GBM) cells via programmed death. Our results indicated that osthole, umbelliferone, esculin, and 4-hydroxycoumarin initiated mainly apoptosis in the T98G and MOGGCCM cells. Osthole was the most effective. It also initiated autophagy in a small percentage of the cell population. The co-incubation with Temozolomide did not increase the pro-apoptotic potential of natural compounds but decreased the level of autophagy in the T98G cells. Apoptosis was associated with reduced mitochondrial membrane potential, activation of caspase 3, inhibition of Bcl-2 expression and the presence of a Bcl-2/Beclin 1. Blocking of Bcl-2 expression resulted in promotion of apoptosis, but not autophagy, in the MOGGCCM and T98G lines. It also sensitized astrocytoma cells, but not GBM, to the combined osthole and TMZ treatment, which was correlated with a reduced level of Beclin 1 and increased expression of caspase 3. Osthole and TMZ, alone and in combination, inhibited the migratory phenotype of the GBM and AA cells. In summary, our results indicated that osthole effectively eliminated glioma cells via apoptosis, what was correlated with Bcl-2/Beclin 1 complex formation. Considering the anti-migratory effect, osthole and Temozolomide display antiglioma potential but it needs further extensive studies.
Subject(s)
Antineoplastic Combined Chemotherapy Protocols/pharmacology , Brain Neoplasms/drug therapy , Coumarins/pharmacology , Glioma/drug therapy , Temozolomide/pharmacology , Apoptosis/drug effects , Autophagy/drug effects , Beclin-1/genetics , Beclin-1/metabolism , Brain Neoplasms/genetics , Brain Neoplasms/metabolism , Brain Neoplasms/pathology , Caspase 3/metabolism , Cell Line, Tumor , Cell Movement/drug effects , Gene Expression Regulation, Neoplastic , Glioma/genetics , Glioma/metabolism , Glioma/pathology , Humans , Membrane Potential, Mitochondrial/drug effects , Necrosis , Proto-Oncogene Proteins c-bcl-2/genetics , Proto-Oncogene Proteins c-bcl-2/metabolism , Signal TransductionABSTRACT
Furanocoumarins are a class of natural compounds produced by several plants, including those consumed by humans. They have been used medicinally in eastern countries for ages. Given the growing body of evidence about their anticancer potential and observations that naturally occurring compounds potentiate the antitumor activity of chemotherapeutics, more attention is paid to elucidation of the nature of furanocoumarins and the possibility of using thereof in practice. The general mechanism by which furanocoumarins eliminate cancer cells is based on cell cycle blockage and initiation of programmed death like apoptosis or autophagy. The precise molecular mechanism of such an action depends on the chemical structure of furanocoumarins, which is based on the furan ring attached to the coumarin backbone in a linear or angular form as well as the type, location, and number of the substituents attached. The review summarizes the current evidence of the antitumor properties of linear and angular furanocoumarins with special emphasis on the molecular mechanism of elimination of cancer cells via apoptosis and autophagy. Negative aspects of the use of coumarins in anticancer therapy will be also discussed especially in the context of their phototoxicity and potential cancerogenic effect.