Apoptosis induction in human leukemic promyelocytic HL-60 and monocytic U937 cell lines by goniothalamin

Circ-UBAP2 functions as sponges of miR-1205 and miR-382 to promote glioma progression by modulating STC1 expression

Background

Circular RNAs (circRNAs) exert vital functions in glioma pathogenesis. CircRNA ubiquitin‐associated protein 2 (circ‐UBAP2, hsa_circ_0008344) has been illuminated as a tumor driver in glioma. Nevertheless, the mechanisms underlying the oncogenic regulation of circ‐UBAP2 in glioma are still undefined.

Methods

Circ‐UBAP2, miR‐1205, miR‐382, and GPRC5A were quantified using qRT‐PCR and western blot. Cell viability was detected using a CCK‐8 assay. Cell migration and invasion were measured using the would‐healing and transwell assays. Flow cytometry and colony formation assay were applied to evaluate cell apoptosis and colony formation, respectively. The xenograft model assays were used to examine the impact of circ‐UBAP2 on tumorigenic effect in vivo. Direct relationships among circ‐UBAP2, miR‐1205, miR‐382, and GPRC5A were confirmed using dual‐luciferase reporter assays.

Results

Circ‐UBAP2 expression was upregulated in glioma. The reduced level of circ‐UBAP2 hampered cell proliferation, migration, invasion, and enhanced apoptosis in vitro and weakened tumor growth in vivo. Mechanistically, circ‐UBAP2 directly bound to miR‐1205 and miR‐382. miR‐1205 and miR‐382 mediated the regulation of circ‐UBAP2 silencing on glioma cell behaviors. Moreover, GPRC5A was a functional target of miR‐1205 and miR‐382 in regulating glioma cell behaviors. Furthermore, circ‐UBAP2 mediated GPRC5A expression through miR‐1205 or miR‐382 in glioma cells.

Conclusion

Our current findings identified that circ‐UBAP2 silencing impeded glioma malignant progression partially by downregulating GPRC5A through targeting miR‐1205 and miR‐382.

Goniothalamin Induces Necroptosis and Anoikis in Human Invasive Breast Cancer MDA-MB-231 Cells

Goniothalamin (GTN) is toxic to several types of cancer cells in vitro. However, its effects on non-apoptotic cell death induction of human cancer cells have been poorly documented. Here, an investigation of the anti-cancer activity of GTN and the molecular signaling pathways of non-apoptotic cell death in the invasive human breast cancer MDA-MB-231 cell line were undertaken. Apoptotic cell death was suppressed by using a pan-caspase inhibitor (Benzyloxycarbonyl-Val-Ala-Asp-[O-methyl]-fluoromethylketone), z-VAD-fmk) as a model to study whether GTN induced caspase-independent cell death. In the anoikis study, MDA-MB-231 cells were cultured on poly-(2-hydroxyethyl methacrylate)- or poly-HEMA- coated plates to mimic anoikis-resistance growth and determine whether GTN induced cell death and the mechanisms involved. GTN and z-VAD-fmk induced human breast cancer MDA-MB-231 cells to undergo necroptosis via endoplasmic reticulum (ER) and oxidative stresses, with increased expressions of necroptotic genes such as rip1, rip3, and mlkl. GTN induced MDA-MB-231 cells to undergo anoikis via reversed epithelial-mesenchymal transition (EMT) protein expressions, inhibited the EGFR/FAK/Src survival signaling pathway, and decreased matrix metalloproteinase secretion.

Apoptosis Induction via ATM Phosphorylation, Cell Cycle Arrest, and ER Stress by Goniothalamin and Chemodrugs Combined Effects on Breast Cancer-Derived MDA-MB-231 Cells

Goniothalamin (GTN), a styryl-lactone, exhibits inhibitory effects on many kinds of cancer cells in vitro. The objectives of this study were to investigate the anticancer activities of GTN and molecular signaling pathways associated with cell death in human breast cancer MDA-MB-231 cell line. GTN inhibited the growth of MDA-MB-231 cells. Apoptosis was confirmed by annexin V-FITC and PI staining, and apoptotic morphology was observed by microscopy. Reduction of mitochondrial transmembrane potential and enhanced caspases activities were found in GTN-treated MDA-MB-231 cells. GTN significantly altered apoptosis-related protein expressions, including Noxa, PUMA, Bax, Bim, Bad, Bcl-2, Bcl-xL, and DIABLO, which was related to the gene expression levels. Mitochondrial calcium released to the cytosol and ER stress related proteins increased, which correlated with increases in ER stress gene expression levels. GTN induced hydrogen peroxide and superoxide anion radicals in MDA-MB-231 cells associated with cell cycle arrest in G2/M phase, which was induced by phosphorylation and ATM gene expression. Moreover, GTN had synergistic effects when combined with cyclophosphamide, 5-fluorouracil, paclitaxel, and vinblastine, and additive effect with methotrexate through caspases enzyme-acceleration. In conclusion, goniothalamin-induced MDA-MB-231 cell apoptosis occurred via intrinsic and extrinsic pathways, along with ER stress. These pathways provide new targeted drug strategies for advancements in anticancer medicine.

Synthesis of fluoro-functionalized diaryl-λ3-iodonium salts and their cytotoxicity against human lymphoma U937 cells

Conscious of the potential bioactivity of fluorine, an investigation was conducted using various fluorine-containing diaryliodonium salts in order to study and compare their biological activity against human lymphoma U937 cells. Most of the compounds tested are well-known reagents for fluoro-functionalized arylation reactions in synthetic organic chemistry, but their biological properties are not fully understood. Herein, after initially investigating 18 fluoro-functionalized reagents, we discovered that the ortho-fluoro-functionalized diaryliodonium salt reagents showed remarkable cytotoxicity in vitro. These results led us to synthesize more compounds, previously unknown sterically demanding diaryliodonium salts having a pentafluorosulfanyl (SF₅) functional group at the ortho-position, that is, unsymmetrical ortho-SF₅ phenylaryl-λ³-iodonium salts. Newly synthesized mesityl(2-(pentafluoro-λ⁶-sulfanyl)phenyl)iodonium exhibited the greatest potency in vitro against U937 cells. Evaluation of the cytotoxicity of selected phenylaryl-λ³-iodonium salts against AGLCL (a normal human B cell line) was also examined.

Mechanism of apoptosis induction associated with ERK1/2 upregulation via goniothalamin in melanoma cells

The present study aimed to investigate the effect of goniothalamin on apoptosis induction in the A375 melanoma cell line. Melanoma is a type of skin cancer with increased prevalence and no potential standard treatment. Goniothalamin is a plant, bioactive styrly-lactone, which has various bioactivities including anti-microbial, anti-inflammatory and anti-cancer. Apoptosis induction by goniothalamin has been studied in numerous cancer cell lines, however not in the melanoma cell line A375. The results of the MTT assay demonstrated that goniothalamin induced anti-proliferation in a dose dependent manner. Hoechst staining assay demonstrated that goniothalamin induced chromatin condensation and apoptotic bodies in A375 treated cells, and JC-1 staining revealed that goniothalamin induced mitochondrial membrane dysfunction in A375 cells. In addition, goniothalamin decreased the level of anti-apoptotic proteins myeloid cell leukemia 1, B cell lymphoma (Bcl)-2 and Bcl-extra large, whereas it increased the level of pro-apoptotic proteins, Bcl-2 Associated X, apoptosis regulator, t-BID and Bim in A375 treated cells. In addition, goniothalamin also increased active caspase-9, -7 and cleaved-poly (ADP-ribose) polymerase expression in A375 treated cells. Furthermore, phosphorylated (p)-pyruvate dehydrogenase kinase (PDK) 1 (Ser241) and p-RAC-alpha serine/threonine-protein kinase (Akt; Ser473) were decreased, however c-Jun and p-extracellular signal-regulated kinase (ERK)1/2 were increased upon goniothalamin treatment. These results suggest that goniothalamin has an effect, as anti-proliferation and apoptosis induction in A375 cells were associated with upregulated p-ERK1/2, c-Jun and downregulated p-PDK1 (Ser241), p-Akt (Ser473) in A375 cells. Therefore, goniothalamin may be a potential candidate for anti-cancer drug development for melanoma treatment.

Goniothalamin induces mitochondria-mediated apoptosis associated with endoplasmic reticulum stress-induced activation of JNK in HeLa cells

Goniothalamin, a natural occurring styryl-lactone isolated from Goniothalamus macrophyllus (Blume) Hook. f. & Thomson var. macrophyllus, can trigger cancer cell death in various types of cancer cell. The present study focused on elucidation of the mitochondria-mediated apoptosis associated with endoplasmic reticulum (ER) stress-induced activation of c-Jun NH₂-terminal kinase (JNK) by goniothalamin in HeLa cervical cancer cells. Cell viability was determined using an MTT assay, and DNA condensation and loss of mitochondrial membrane potential were determined using Hoechst 33342 and JC-1 staining, respectively. Flow cytometry was used for cell cycle and phosphatidyl-serine exposure analyses. Apoptotic-associated ER stress signaling pathways were determined using immunoblotting, reverse transcription-polymerase chain reaction (RT-PCR) and RT-quantitative PCR analyses. The results suggested that goniothalamin suppressed cell proliferation in a time- and dose-dependent manner. The induction of apoptosis was confirmed by increased DNA condensation, loss of mitochondrial membrane potential and cell surface phosphatidyl-serine presentation. The cell cycle analysis demonstrated that the goniothalamin-treated HeLa cells were in G2/M arrest. Determination of the caspase cascade and apoptotic proteins indicated the induction of apoptosis through the intrinsic pathway. In addition, the levels of phosphorylated JNK and the transcription factor, C/EBP homologous protein (CHOP), an ER stress-associated apoptotic molecule, were increased in the goniothalamin-treated cells. These data indicated that goniothalamin exerted a cytotoxic effect against HeLa cells via the induction of mitochondria-mediated apoptosis, associated with ER stress-induced activation of JNK.

Metformin induces apoptosis via a mitochondria-mediated pathway in human breast cancer cells in vitro

Breast cancer is the most commonly occurring cancer and second leading cause of mortality in women. Metformin is a widely prescribed anti-hyperglycemic drug, which is emerging as a potential cancer preventative and treatment agent. However, the mechanisms underlying the suppressive effects of metformin on cancer cell growth and the induction of cancer cell apoptosis are not fully elucidated. The present study aimed to identify the pathways regulated by metformin in two breast cancer cell lines, MDA-MB-231 and MDA-MB-435. Cells were treated with various concentrations of metformin and then evaluated with respect to viability, proliferation, adenosine triphosphate (ATP) and reactive oxygen species (ROS) levels, mitochondrial membrane potential (∆ψm), and the expression of anti- and pro-apoptotic proteins. Metformin caused apoptosis in a concentration- and time-dependent manner, and decreased cell viability and ATP production. Furthermore, metformin induced the generation of ROS and decreased the ∆ψm. Moreover, metformin downregulated the expression of the anti-apoptotic proteins B-cell lymphoma 2 (BCL-2) and myeloid cell leukemia-1, and upregulated the expression of the pro-apoptotic BCL-2-associated X protein in MDA-MB-231 cells. These results demonstrate that the apoptotic and cytotoxic effects of metformin on breast cancer cells are mediated by the intrinsic mitochondria-mediated apoptosis pathway.

Antiproliferative activity of goniothalamin enantiomers involves DNA damage, cell cycle arrest and apoptosis induction in MCF-7 and HB4a cells

(R)-goniothalamin (R-GNT) is a styryl lactone that exhibits antiproliferative property against several tumor cell lines. (S)-goniothalamin (S-GNT) is the synthetic enantiomer of R-GNT, and their biological properties are poorly understood. The aim of this study was to evaluate the antiproliferative mechanisms of (R)-goniothalamin and (S)-goniothalamin in MCF-7 breast cancer cells and HB4a epithelial mammary cells. To determine the mechanisms of cell growth inhibition, we analyzed the ability of R-GNT and S-GNT to induce DNA damage, cell cycle arrest and apoptosis. Moreover, the gene expression of cell cycle components, including cyclin, CDKs and CKIs, as well as of genes involved in apoptosis and the DNA damage response were evaluated. The natural enantiomer R-GNT proved more effective in both cell lines than did the synthetic enantiomer S-GNT, inhibiting cell proliferation via cell cycle arrest and apoptosis induction, likely in response to DNA damage. The cell cycle inhibition caused by R-GNT was mediated through the upregulation of CIP/KIP cyclin-kinase inhibitors and through the downregulation of cyclins and CDKs. S-GNT, in turn, was able to cause G0/G1 cell cycle arrest and DNA damage in MCF-7 cells and apoptosis induction only in HB4a cells. Therefore, goniothalamin presents potent antiproliferative activity to breast cancer cells MCF-7. However, exposure to goniothalamin brings some undesirable effects to non-tumor cells HB4a, including genotoxicity and apoptosis induction.

Emerging anticancer potentials of goniothalamin and its molecular mechanisms

The treatment of most cancers is still inadequate, despite tremendous steady progress in drug discovery and effective prevention. Nature is an attractive source of new therapeutics. Several medicinal plants and their biomarkers have been widely used for the treatment of cancer with less known scientific basis of their functioning. Although a wide array of plant derived active metabolites play a role in the prevention and treatment of cancer, more extensive scientific evaluation of their mechanisms is still required. Styryl-lactones are a group of secondary metabolites ubiquitous in the genus Goniothalamus that have demonstrated to possess antiproliferative activity against cancer cells. A large body of evidence suggests that this activity is associated with the induction of apoptosis in target cells. In an effort to promote further research on the genus Goniothalamus, this review offers a broad analysis of the current knowledge on Goniothalamin (GTN) or 5, 6, dihydro-6-styryl-2-pyronone (C₁₃H₁₂O₂), a natural occurring styryl-lactone. Therefore, it includes (i) the source of GTN and other metabolites; (ii) isolation, purification, and (iii) the molecular mechanisms of actions of GTN, especially the anticancer properties, and summarizes the role of GTN which is crucial for drug design, development, and application in future for well-being of humans.