Cancer cells use nutrients like D-glucose (Glc) and L-glutamine (Q) more efficiently for their development. This increased nutritional dependency of malignant cells has been commonly employed in various in vitro and in vivo models of anticancer therapies. This study utilized a combination of a low dose (25 μg mL−1) of S2, a phytosynthesized gold nanoparticle (AuNP) that was previously proven to be non-toxic, and deprivation of extracellular glutamine as an anticancer strategy in the human cervical cancer cell line HeLa. We discovered that 24 h Q deprivation led to a less significant decrease in the viability of HeLa cells while a low dose of S2 caused a non-significant reduction in the viability of HeLa cells. However, combining these two treatments resulted in highly significant inhibition of cell growth, as measured by the MTT test and morphological examination. Glutamine starvation in HeLa cells was found to induce cellular uptake of S2 via clathrin-mediated endocytosis, thus facilitating the improved antitumor effects of the combined treatment. Flow cytometry-based assays using fluorescent probes H2DCFDA and MitoSOX Red confirmed that this combination therapy involved the development of oxidative stress conditions owing to a surplus of cytosolic reactive oxygen species (cytoROS) and mitochondrial superoxide (mtSOX) generation. Furthermore, the investigated combinatorial treatment also indicated mitochondrial inactivity and disintegration, as evidenced by the drop in the mitochondrial membrane potential (Δψm) and the decrease in the mitochondrial mass (mtMass) in a flow-cytometric assay utilizing the probes. Tetramethylrhodamine ethyl ester and MitoTracker Green FM, respectively. Cell cycle arrest in the G0/G1 phase, induction of cell death via apoptosis/necrosis, and inhibition of migration capacities of HeLa cells were also seen after the combined treatment. Thus, this research provides insight into a new combinatorial approach for reducing the dose of nanoparticles and increasing their efficacy to better inhibit the growth of human cervical cancer cells by leveraging their extracellular glutamine dependence.
1 April 2015 in Journal of Trace Elements in Medicine and Biology
Current studies are focusing on the anti-cancerous properties of natural bioactive compounds, primarily those included in the human diet. These compounds have the potential to alter the redox balance that can hinder cancer cell's growth. In cancer cells, an abnormal rate of ROS production is balanced with higher antioxidant activities, which if not maintained, results in cancer cells being prone to cell death due to oxidative stress. Here, we have analyzed the effects of Chrysin and Capsaicin on the HeLa cells viability and cellular redox signaling. Both these compounds stimulate cellular and mitochondrial ROS overproduction that perturbs the cellular redox state and results in mitochondrial membrane potential loss. Apart from this, these compounds induce cell cycle arrest and induce premature senescence, along with the overexpression of p21, p53, and p16 protein at lower concentration treatment of Chrysin or Capsaicin. Moreover, at higher concentration treatment with these compounds, pro-apoptotic activity was observed with the high level of Bax and cleaved caspase-3 along with suppression of the Bcl-2 protein levels. In-Silico analysis with STITCH v5 also confirms the direct interaction of Chrysin and Capsaicin with target protein p53. This suggests that Chrysin and Capsaicin trigger an increase in mitochondrial ROS, and p53 interaction leading to premature senescence and apoptosis in concentration dependent manner and have therapeutic potential for cancer treatment.
11 December 2023 in Journal of Materials Chemistry B
This study delves into investigating alternative methodologies for anti-microbial therapy by focusing on the mechanistic assessment of carbon dots (CDs) synthesized from F. benghalensis L. extracts.
The ubiquitous hyaladherin, hyaluronan-binding protein 1 (HABP1/p32/gC1qR) upon stable overexpression in normal fibroblasts (F-HABP07) has been reported to induce mitochondrial dysfunction, growth retardation and apoptosis after 72 h of growth. HABP1 has been observed to accumulate in the mitochondria resulting in generation of excess Reactive Oxygen Species (ROS), mitochondrial Ca++ efflux and drop in mitochondrial membrane potential. In the present study, autophagic vacuolation was detected with monodansylcadaverin (MDC) staining from 36 h to 60 h of culture period along with elevated level of ROS in F-HABP07 cells. Increased expression of autophagic markers like MAP-LC3-II, Beclin 1 and autophagic modulator, DRAM confirmed the occurrence of the phenomenon. Reduced vacuole formation was observed upon treatment with 3-MA, a known PI3 kinase inhibitor, only at 32 h and was ineffective if treated later, as high ROS level was already attained. Treatment of F111 and F-HABP07 cells with bafilomycin A1 further indicated an increase in autophagosome formation along with autophagic degradation in HABP1 overexpressed fibroblasts. Comparison between normal fibroblast (F111) and F-HABP07 cells indicate reduced level of polymeric HA, its depolymerization and perturbed HA-HABP1 interaction in F-HABP07. Interestingly, supplementation of polymeric HA, an endogenous ROS scavenger, in the culture medium prompted reduction in number of vacuoles in F-HABP07 along with drop in ROS level, implying that excess ROS generation triggers initiation of autophagic vacuole formation prior to apoptosis due to overexpression of HABP1. Thus, the phenomenon of autophagy takes place prior to apoptosis induction in the HABP1 overexpressing cell line, F-HABP07.