Toxicology in Vitro

Glycyrrhizic acid enhances the anticancer activity of cisplatin in the human ovarian cancer cell line

This study aimed to investigate the effects of glycyrrhizic acid (GL) on the anticancer activity of cisplatin in A2780 ovarian cancer cells. Cultured A2780 cells were treated with different concentrations of GL and cisplatin individually and in combination. The MTT assay, flow cytometry, wound-healing, and clonogenic assay, were used to determine cell viability, apoptosis, migration, and colony formation, respectively. The effects on superoxide dismutase (SOD) activity were also evaluated. QPCR was used to study the effects of individual and combined treatments with GL and cisplatin on the expression levels of migration genes (MMP2 and MMP9), and some apoptosis pathway genes (caspase-3, -8, -9, and BCL2). A synergistic effect was observed between GL and cisplatin (CI < 1). Combination therapy was significantly more effective in reducing cell viability, suppressing migration and colony formation, inducing apoptosis, and altering gene expression compared to single therapies. GL significantly increased SOD activity. The relative expression of caspase -3, -8, and - 9 increased significantly, and the expression levels of MMP2 and MMP9 decreased significantly in the treated cells. Our results indicate that GL enhances the anticancer activity of cisplatin in the A2780 cell line. Therefore, the combination of GL and cisplatin can be proposed as a promising therapeutic strategy for ovarian cancer.

Persistent endocrine-disrupting chemicals found in human follicular fluid stimulate IGF1 secretion by adult ovarian granulosa cell tumor spheroids and thereby increase proliferation of non-cancer ovarian granulosa cells

Insulin-like growth factor-1 (IGF1) is a hormone involved in cell proliferation. We previously showed that IGF1 directly stimulates cell proliferation in granulosa cell tumors (GCTs). Estrogen regulates IGF1 expression in several reproductive organs including the uterus and ovaries. This study aimed to investigate the effects of a mixture of endocrine-disrupting chemicals (EDCs) on secretion of IGF1 by COV434 and KGN cells, which have been used as in vitro models of juvenile and adult GCTs, respectively. The EDC mixture contained perfluorooctanoate, perfluorooctane sulfonate, 2,2-dichlorodiphenyldichloroethylene, hexachlorobenzene, and polychlorinated biphenyl 153, which are persistent hormonally active environmental toxicants present in ovarian follicular fluid (FF). Expression and secretion of IGF1 were significantly higher in GTCs than in HGrC1 human non-cancer granulosa cells (with the profile HGrC1 < COV434 < KGN). Treatment with the EDC mixture as well as individual test compounds significantly increased IGF1 secretion in KGN cells. Moreover, IGFBP3 gene expression in KGN cells was downregulated after treatment with the EDC mixtures. The estrogen receptor alpha pathway was involved in this effect. Conditioned medium of KGN cells treated with the EDC mixture increased proliferation of HGrC1 human non-cancer granulosa cells. These results indicate that the mixture of EDCs found in FF increases secretion of IGF1 by KGN cells and thus indirectly contributes to progression of adult GCTs, and increases proliferation of non-cancer granulosa cells.

A novel synergistic anticancer effect of fungal cholestanol glucoside and paclitaxel: Apoptosis induced by an intrinsic pathway through ROS generation in cervical cancer cell line (HeLa)

In the search for efficient therapeutics with economically viable for cancer treatment, combination therapy has developed as a keystone in the pursuit of novel approaches for drug discovery. In this regard, we confirmed the presence of cholestanol glucoside (CG) in Lasiodiplodia theobromae culture filtrate and its production was estimated to be 20.01 mg/l. The purified fungal CG was obtained with a molecular mass of 550.18 m/z. The combination of CG and paclitaxel (PTX) was found to have potent cytotoxicity against HeLa cells. We revealed that the synergistic effect of CG and PTX induced apoptosis through the formation of nuclear fragments, DNA fragmentation and sub G1 cell cycle arrest. Further, it was proven that apoptosis took place by loss of the mitochondrial membrane potential (MMP) through reactive oxygen species (ROS) production and caspase 3/7 activity. Moreover, the data suggests that the synergistic effect of CG and PTX played a role in a mitochondrial intrinsic pathway through the apoptotic gene expression of Bax, caspase-9 and caspase-3. In addition, the down-regulation of Bcl-2 strongly described the induced apoptosis through an intrinsic pathway using the Western blot analysis. The conclusion of this study is that a combination of CG and PTX has synergistic apoptotic effects in HeLa cells, which provides a possible therapeutic strategy for cancer therapy in the future.

Plumbagin downregulates UHRF1, p-Akt, MMP-2 and suppresses survival, growth and migration of cervical cancer CaSki cells

Plumbagin is a natural compound known to impede growth of cancerous cells. However, anti-cervical cancer effects of plumbagin and its underlying molecular mechanism still remains elusive. In this study, plumbagin reduced the viability of CaSki cells in a concentration dependent manner and suppressed their colony formation potential. It led to G2/M phase arrest with downregulation of E2F1 and upregulation of p21. Plumbagin reduced mitochondrial membrane potential and concomitantly increased the percentage of apoptotic cells as revealed by annexin V-propidium iodide staining. Real Time PCR and western blotting confirmed that plumbagin induced apoptosis by reducing the expression of pAkt, procaspase 9 and full-length PARP. Furthermore, scratch assay showed that plumbagin suppressed migratory potential of CaSki cells which could be due to the reduced expression and activity of MMP-2 and upregulation of TIMP2. Interestingly, plumbagin also downregulated UHRF1 expression. Transient silencing of UHRF1 like plumbagin, induced G2/M phase arrest, enhanced apoptosis and suppressed metastasis of CaSki cells suggesting the role of UHRF1 in mediating anti-cancer activities of plumbagin. Plumbagin at IC

Cadmium sulfide nanoparticles (CdSNPs) modulate key oncogenic pathways in PA1 ovarian cancer cells: Insights from transcriptomic analysis

Transcriptomics has become a useful tool for comparing the levels of gene expression in healthy and malignant cells, holding potential for the discovery of new cancer therapies. This study used RNA-sequencing and transcriptome analysis on the PA1 ovarian cancer cell line to examine the potential of Cadmium Sulfide Nanoparticles (CdSNPs) as a therapeutic agent. A total of 5.42 Gb of high-quality reads was estimated based on the findings of gene expression techniques, comprising 2.25 Gb of treated PA1 cells and 3.17 Gb of control cells. Of these, 1641 genes with padj2 were found to be significantly regulated DEGs (differentially expressed genes). Analysis of gene ontology (GO) assays demonstrates the molecular mechanism behind CdSNPs anticancer effects. GO:0006915, GO:0012501, GO:1903561, and GO:0070588 are a few significant highlights of elevated GO (enriched DEGs) that are involved in apoptotic pathways, extracellular vesicles, programmed cell death, and Ca++ signaling. KEGG analysis elucidated that up and downregulated DEGs were enriched in a few pathways: calcium signaling pathway, Apoptosis, and TNF signaling pathway. Important pathways like MAP kinase, JAK/STAT, cAMP, and folate biosynthesis, showed inhibitory effects on ovarian cancer cell proliferation. The results of this work provide insight into possible therapeutic approaches employing CdSNPs and encourage additional research using a variety of cell lines and in vivo models to improve ovarian cancer treatment.

Chelerythrine hydrochloride inhibits proliferation and induces mitochondrial apoptosis in cervical cancer cells via PI3K/BAD signaling pathway

Cervical cancer is the fourth most common female cancer worldwide, and drug targeted therapy plays a crucial role in delaying the progression of cervical carcinoma. Chelerythrine hydrochloride (CHE) is a natural alkaloid, which is a focal point in anti-tumor research. In this study, we investigated the effect of CHE on HeLa cells by using MTT assay, RTCA, and colony formation assay. In addition, the flow cytometric analysis, immunofluorescence staining assay and western blot analysis were performed to study the mechanism of CHE. The results showed that CHE exhibited a significant inhibitory effect in HeLa cells, and it could suppress the expression of PI3K subunits in a dose-dependent manner. Moreover, we found that the treatment of CHE further restrained the downstream AKT/mTOR and PKCα signaling. In addition, CHE induced mitochondrial apoptosis of HeLa cells by regulating the BCL-2 family member's expression. Immunofluorescence staining assay indicated that AIF and Cytochrome C were translocated from mitochondria to cytoplasm or nucleus, and notable changes in mitochondrial morphology of HeLa cells were also observed. Finally, the aberrant expression of CHE led to the mitochondrial apoptosis by upregulating the expression of APAF1, Cleaved-Caspase9, Cleaved-Caspase3, and Cleaved-PARP. In summary, CHE suppresses the proliferation of HeLa cells by trigging the mitochondrial apoptosis through the PI3K/BAD signaling pathway.

Dual effects of metformin and resveratrol on compromising viability of endometrial cancer cells

Raising of mitogenic and anti-apoptotic agents - such as insulin, insulin-like growth factor type 1, and estrogen - during obesity and diabetes mellitus (types 1 and 2) favors the endometrial cancer (EC) development. Metformin, commonly used for treating type 2 diabetes, and resveratrol, a natural polyphenol, can both decrease cancer cell proliferation by modulating the PI3K/Akt/mTOR pathway. We evaluate the effects of metformin and/or resveratrol in an in vitro model of human type 1 endometrioid EC. Ishikawa cells were treated with 0.1 to 50 mM of metformin and/or 0.1 to 75 μM of resveratrol from 24 h to 72 h. Analyses assessed cell viability, cytotoxicity, caspases activation, mitochondrial function, cellular death, cell cycle, and the PI3K/Akt/mTOR pathway gene expression. In-silico analysis was conducted using Cytoscape. Metformin induced mitochondrial swelling, caspase-mediated apoptosis, and cell cycle arrest. Resveratrol decreased mitochondrial mass, cytotoxicity, and induced cell cycle arrest. Combined treatment with the highest concentrations reduced mitochondrial activity, cytotoxicity, and caspase activation while maintaining apoptotic features and cell cycle arrest. Resveratrol attenuated the toxic effects of metformin but it could be inducing a caspase-independent cell death in co-treated cells. Although in-silico analysis suggested potential molecular targets and interconnected mechanisms, lower concentrations did not alter PI3K/Akt/mTOR gene expression.

Discovering the structure–activity relationships of different O-prenylated coumarin derivatives as effective anticancer agents in human cervical cancer cells

Cervical cancer remains one of the greatest life threatening diseases for women worldwide. Although chemotherapy is considered as a standard treatment for advanced cervical cancers, there are still some drawbacks in this procedure including side effects and acquired drug resistance, which necessitate further research on development of more effective agents with less side effects. Among natural compounds, coumarin derivatives have shown anticancer properties on various cancerous cells and coumarin ring has proven to have a paramount role in development of anticancer drugs. Here, we aimed to establish the structure-activity relationships of eighteen O-prenylated coumarin derivatives and determined their anticancer properties on HeLa cervical cancer and HDF normal cells by MTT assay. Moreover, the mechanism of cell death induced by these compounds and their effects on cell cycle were studied using flow cytometry. MTT results indicated that twelve O-prenylated coumarin derivatives exhibited selective toxicity on HeLa cells, while they had no significant toxic effects on normal cells. Besides, flow cytometric analyses, showed that the selected compounds induced apoptosis in HeLa cells, and could also result to G