Geranylated 4-phenylcoumarins extracted from Mesua elegans induced caspase-independent cell death in prostate cancer cell lines through calpain-2 and cathepsin B

Photodynamic therapy of cancer using graphene nanomaterials

INTRODUCTION

High incidence and fatality rates of cancer remain a global challenge. The success of conventional treatment modalities is being questioned on account of adverse effects. Photodynamic therapy (PDT) is a potential alternative. It utilizes a combination of photosensitizer (PS), light and oxygen to target the tissues locally, thereby minimizing the damage to neighboring healthy tissues. Conventional PSs suffer from poor selectivity, high hydrophobicity and sub-optimal yield of active radicals. Graphene nanomaterials (GNs) exhibit interesting particulate and photophysical properties in the context of their use in PDT.

AREA COVERED

We focus on describing the mechanistic aspects of PDT-mediated elimination of cancer cells and the subsequent development of adaptive immunity. After covering up-to-date literature on the significant enhancement of PDT capability with GNs, we have discussed the probability of combining PDT with chemo-, immuno-, and photothermal therapy to make the treatment more effective.

EXPERT OPINION

GNs can be synthesized in various size ranges, and their biocompatibility can be improved through surface functionalization and doping. These can be used as PS to generate ROS or conjugated with other PS molecules for treating deep-seated tumors. With increasing evidence on biosafety, such materials offer hope as antitumor therapeutics.

The endoplasmic reticulum stress response in prostate cancer

In order to proliferate in unfavourable conditions, cancer cells can take advantage of the naturally occurring endoplasmic reticulum-associated unfolded protein response (UPR) via three highly conserved signalling arms: IRE1α, PERK and ATF6. All three arms of the UPR have key roles in every step of tumour progression: from cancer initiation to tumour growth, invasion, metastasis and resistance to therapy. At present, no cure for metastatic prostate cancer exists, as targeting the androgen receptor eventually results in treatment resistance. New research has uncovered an important role for the UPR in prostate cancer tumorigenesis and crosstalk between the UPR and androgen receptor signalling pathways. With an improved understanding of the mechanisms by which cancer cells exploit the endoplasmic reticulum stress response, targetable points of vulnerability can be uncovered.

Silencing of α-N-acetylgalactosaminidase in the gastric cancer cells amplified cell death and attenuated migration, while the multidrug resistance remained unchanged

Although the elevated level of the α-N-acetylgalactosaminidase enzyme (encoded by the NAGA gene) is a well-recognized feature of cancer cells; little research works have been undertaken on the cancer malignancy mechanisms. The effects of NAGA gene downregulation on cancer cells' features such as drug resistance, impaired programmed cell death, and migration were analyzed in this study. The cells grew exponentially with a doubling time of 30 h in an optimal condition. Toxicity of daunorubicin chemotherapy drug on NAGA-transfected EPG85.257RDB cells was evaluated in comparison to control cells and no significant change was recorded. Quantitative transcript analyses and protein levels revealed that the MDR1 pump almost remained unchanged during the study. Moreover, the NAGA gene downregulation enhanced the late apoptosis rate in EPG85.257RDB cells at 24 h posttransfection. The investigated expression level of genes and proteins involved in the TNFR2 signaling pathway, related to cancer cell apoptosis, showed considerable alterations after NAGA silencing as well. MAP3K14 and CASP3 genes were downregulated while IL6, RELA, and TRAF2 experienced an upregulation. Also, NAGA silencing generally diminished the migration ability of EPG85.257RDB cells and the MMP1 gene (as a critical gene in metastasis) expression decreased significantly. The expression of the p-FAK protein, which is located in the downstream of the α₂ β₁ integrin signaling pathway, was reduced likewise. It could be concluded that despite drug resistance, NAGA silencing resulted in augmentative and regressive effects on cell death and migration.

Improving ligand-ranking of AutoDock Vina by changing the empirical parameters

AutoDock Vina (Vina) achieved a very high docking-success rate, p ^ , but give a rather low correlation coefficient, R , for binding affinity with respect to experiments. This low correlation can be an obstacle for ranking of ligand-binding affinity, which is the main objective of docking simulations. In this context, we evaluated the dependence of Vina R coefficient upon its empirical parameters. R is affected more by changing the gauss2 and rotation than other terms. The docking-success rate p ^ is sensitive to the alterations of the gauss1, gauss2, repulsion, and hydrogen bond parameters. Based on our benchmarks, the parameter set1 has been suggested to be the most optimal. The testing study over 800 complexes indicated that the modified Vina provided higher correlation with experiment R set 1 = 0.556 ± 0.025 compared with R Default = 0.493 ± 0.028 obtained by the original Vina and R Vina 1.2 = 0.503 ± 0.029 by Vina version 1.2. Besides, the modified Vina can be also applied more widely, giving R ≥ 0.500 for 32/48 targets, compared with the default package, giving R ≥ 0.500 for 31/48 targets. In addition, validation calculations for 1036 complexes obtained from version 2019 of PDBbind refined structures showed that the set1 of parameters gave higher correlation coefficient ( R set 1 = 0.617 ± 0.017 ) than the default package ( R Default = 0.543 ± 0.020 ) and Vina version 1.2 ( R Vina 1.2 = 0.540 ± 0.020 ). The version of Vina with set1 of parameters can be downloaded at https://github.com/sontungngo/mvina. The outcomes would enhance the ranking of ligand-binding affinity using Autodock Vina.