Drug-free phototherapy of superficial tumors: White light at the end of the tunnel

Maintaining KEAP1 levels in retinal pigment epithelial cells preserves their viability during prolonged exposure to artificial blue light

Exposure to artificial blue light, one of the most energetic forms of visible light, can increase oxidative stress in retinal cells, potentially enhancing the risk of macular degeneration. Retinal pigment epithelial (RPE) cells play a crucial role in this process; the loss of RPE cells is the primary pathway through which retinal degeneration occurs. In RPE cells, Kelch-like ECH-associated protein 1 (KEAP1) is located in both the nucleus and cytosol, where it binds to nuclear factor erythroid 2-related factor 2 (NRF2) and p62 (sequestosome-1), respectively. Blue light exposure activates the NRF2-heme oxygenase 1 (HMOX1) axis through both canonical and noncanonical p62 pathways thereby reducing oxidative damage, and initiates autophagy, which helps remove damaged proteins. These protective responses may support the survival of RPE cells. However, extended exposure to blue light drastically decreases the viability of RPE cells. This exposure diminishes the ability of KEAP1 to bind to p62 and reduces the level of KEAP1. Inhibition of autophagy does not prevent KEAP1 degradation, the NRF2-HMOX1 axis, or blue-light-induced cytotoxicity. However, proteasome inhibitor along with a transient increase in the amount of KEAP1 in RPE cells, partially restores the p62-KEAP1 complex and reduces blue-light-induced cytotoxicity. In vivo studies confirmed the downregulation of KEAP1 in damaged RPE cells. Mice subjected to periodic blue light exposure exhibited significant atrophy in the outer retina, particularly in the peripheral areas. Additionally, there was a significant decrease in c-wave electroretinography and pupillary light reflex, indicating functional impairments in both visual and nonvisual physiological processes. These data underscore the essential role of KEAP1 in managing oxidative defense and autophagy pathways triggered by blue light exposure in RPE cells.

Effect of 460 nm blue light PBM on human MeWo melanoma cells

Photobiomodulation (PBM) using 460 nm blue light has been shown to have an inhibitory effect on skin cancer cells. In this study, we used a continuous LED light source with a wavelength of 460 nm and designed various combinations of power density (ranging from 6.4 to 25.6 mW) and dose (ranging from 0.96 to 30.72 J/cm2) to conduct treatment experiments on MeWo cells to investigate the effects of blue light on MeWo melanoma cells. We are focusing on cell viability, cytotoxicity, mitochondrial function, oxidative stress, and apoptosis. We found that blue light inhibits these melanoma cells through oxidative stress and DNA damage, and this inhibition intensifies at higher irradiance levels. Although the cells initially attempt to resist the stress induced by the treatment, they eventually undergo apoptosis over time. These findings contribute to understanding melanoma's molecular response to blue light PBM, lay the groundwork for future clinical applications.

Platinum(IV) Prodrugs Incorporating an Indole-Based Derivative, 5-Benzyloxyindole-3-Acetic Acid in the Axial Position Exhibit Prominent Anticancer Activity

Kinetically inert platinum(IV) complexes are a chemical strategy to overcome the impediments of standard platinum(II) antineoplastic drugs like cisplatin, oxaliplatin and carboplatin. In this study, we reported the syntheses and structural characterisation of three platinum(IV) complexes that incorporate 5-benzyloxyindole-3-acetic acid, a bioactive ligand that integrates an indole pharmacophore. The purity and chemical structures of the resultant complexes, P-5B3A, 5-5B3A and 56-5B3A were confirmed via spectroscopic means. The complexes were evaluated for anticancer activity against multiple human cell lines. All complexes proved to be considerably more active than cisplatin, oxaliplatin and carboplatin in most cell lines tested. Remarkably, 56-5B3A demonstrated the greatest anticancer activity, displaying GI50 values between 1.2 and 150 nM. Enhanced production of reactive oxygen species paired with the decline in mitochondrial activity as well as inhibition of histone deacetylase were also demonstrated by the complexes in HT29 colon cells.

Enhanced potency of a chloro-substituted polyaromatic platinum(II) complex and its platinum(IV) prodrug against lung cancer

The present study investigates the anti-neoplastic activity of a platinum (II) complex, Pt(II)5ClSS, and its platinum (IV) di-hydroxido analogue, Pt(IV)5ClSS, against mesenchymal cells (MCs), lung (A549), melanoma (A375) and breast (MDA-MB-231) cancer cells. Both complexes exhibited up to 14-fold improved cytotoxicity compared to cisplatin. NMR was used to determine that ∼25 % of Pt(IV)5ClSS was reduced to Pt(II)5ClSS in the presence of GSH (Glutathione) after 72 h. The complex 1H NMR spectra acquired for Pt(II)5ClSS with GSH shows evidence of degradation and environmental effects (∼30 %). The prominence of the 195Pt peak at ∼ -2800 ppm suggests that a significant amount of Pt(II)5ClSS remained in the mixture. Pt(II)5ClSS and Pt(IV)5ClSS have shown exceptional selectivity to cancer cells in comparison to MCs (IC50 > 150 μM). Western blot analysis of Pt(II)5ClSS and Pt(IV)5ClSS on A549 cells revealed significant upregulation of cleaved PARP-1, BAX/Bcl2 ratio, cleaved caspase 3 and cytochrome thus suggesting apoptosis was induced through the intrinsic pathway. Flow cytometry also revealed significant cell death by apoptosis. Treatment with Pt(II)5ClSS and Pt(IV)5ClSS also showed significant amounts of free radical production while the COMET assay showed that both complexes cause minimal DNA damage. Cellular uptake results via ICP-MS suggest a time-dependent active mode of transport for both complexes with Pt(II)5ClSS being transported at a higher rate compared to Pt(IV)5ClSS. A Dose Escalation Study carried out on BALB/c mice showed that Pt(II)5ClSS and Pt(IV)5ClSS were approximately 8- folds and 12.5-folds, respectively, more tolerated than cisplatin. The present study provides evidence that both complexes may have the characteristics of an efficient and potentially safe anti-tumor drug that could support NSCLC treatment.

A Ru(II)-Strained Complex with 2,9-Diphenyl-1,10-phenanthroline Ligand Induces Selective Photoactivatable Chemotherapeutic Activity on Human Alveolar Carcinoma Cells via Apoptosis

[Ru(bipy)2(dpphen)]Cl2 (where bipy = 2,2'-bipyridine and dpphen = 2,9-diphenyl-1,10-phenanthroline) (complex 1) is a sterically strained compound that exhibits promising in vitro photocytotoxicity on an array of cell lines. Since lung adenocarcinoma cancer remains the most common lung cancer and the leading cause of cancer deaths, the current study aims to evaluate the plausible effect and uptake of complex 1 on human alveolar carcinoma cells (A549) and mesenchymal stem cells (MSC), and assess its cytotoxicity in vitro while considering its effect on cell morphology, membrane integrity and DNA damage. MSC and A549 cells showed similar rates of complex 1 uptake with a plateau at 12 h. Upon photoactivation, complex 1 exhibited selective, potent anticancer activity against A549 cells with phototoxicity index (PI) values of 16, 25 and 39 at 24, 48 and 72 h, respectively. This effect was accompanied by a significant increase in A549-cell rounding and detachment, loss of membrane integrity and DNA damage. Flow cytometry experiments confirmed that A549 cells undergo apoptosis when treated with complex 1 followed by photoactivation. In conclusion, this present study suggests that complex 1 might be a promising candidate for photochemotherapy with photoproducts that possess selective anticancer effects in vitro. These results are encouraging to probe the potential activity of this complex in vivo.

Urtica dioica Leaf Infusion Enhances the Sensitivity of Triple-Negative Breast Cancer Cells to Cisplatin Treatment

Urtica dioica (UD) has been widely used in traditional medicine due to its therapeutic benefits, including its anticancer effects. Natural compounds have a promising potential when used in combination with chemotherapeutic drugs. The present study explores the anticancer and anti-proliferative properties of UD tea in combination with cisplatin on MDA-MB-231 breast cancer cells in vitro. To elucidate the effect of this combination, a cell viability assay, Annexin V/PI dual staining, cell death ELISA, and Western blots were performed. The results showed that the combination of UD and cisplatin significantly decreased the proliferation of MDA-MB-231 cells in a dose- and time-dependent manner compared to each treatment alone. This was accompanied by an increase in two major hallmarks of apoptosis, the flipping of phosphatidylserine to the outer membrane leaflet and DNA fragmentation, as revealed by Annexin V/PI staining and cell death ELISA, respectively. DNA damage was also validated by the upregulation of the cleaved PARP protein as revealed by Western blot analysis. Finally, the increase in the Bax/Bcl-2 ratio further supported the apoptotic mechanism of death induced by this combination. Thus, a leaf infusion of Urtica dioica enhanced the sensitivity of an aggressive breast cancer cell line to cisplatin via the activation of apoptosis.

Versatile Platinum(IV) Prodrugs of Naproxen and Acemetacin as Chemo-Anti-Inflammatory Agents

Developing new and versatile platinum(IV) complexes that incorporate bioactive moieties is a rapidly evolving research strategy for cancer drug discovery. In this study, six platinum(IV) complexes (1-6) that are mono-substituted in the axial position with a non-steroidal anti-inflammatory molecule, naproxen or acemetacin, were synthesised. A combination of spectroscopic and spectrometric techniques confirmed the composition and homogeneity of 1-6. The antitumour potential of the resultant complexes was assessed on multiple cell lines and proved to be significantly improved compared with cisplatin, oxaliplatin and carboplatin. The platinum(IV) derivatives conjugated with acemetacin (5 and 6) were determined to be the most biologically potent, demonstrating GI₅₀ values ranging between 0.22 and 250 nM. Remarkably, in the Du145 prostate cell line, 6 elicited a GI₅₀ value of 0.22 nM, which is 5450-fold more potent than cisplatin. A progressive decrease in reactive oxygen species and mitochondrial activity was observed for 1-6 in the HT29 colon cell line, up to 72 h. The inhibition of the cyclooxygenase-2 enzyme was also demonstrated by the complexes, confirming that these platinum(IV) complexes may reduce COX-2-dependent inflammation and cancer cell resistance to chemotherapy.

Bioactive Platinum(IV) Complexes Incorporating Halogenated Phenylacetates

A new series of cytotoxic platinum(IV) complexes (1-8) incorporating halogenated phenylacetic acid derivatives (4-chlorophenylacetic acid, 4-fluorophenylacetic acid, 4-bromophenylacetic acid and 4-iodophenylacetic acid) were synthesised and characterised using spectroscopic and spectrometric techniques. Complexes 1-8 were assessed on a panel of cell lines including HT29 colon, U87 glioblastoma, MCF-7 breast, A2780 ovarian, H460 lung, A431 skin, Du145 prostate, BE2-C neuroblastoma, SJ-G2 glioblastoma, MIA pancreas, the ADDP-resistant ovarian variant, and the non-tumour-derived MCF10A breast line. The in vitro cytotoxicity results confirmed the superior biological activity of the studied complexes, especially those containing 4-fluorophenylacetic acid and 4-bromophenylacetic acid ligands, namely 4 and 6, eliciting an average GI₅₀ value of 20 nM over the range of cell lines tested. In the Du145 prostate cell line, 4 exhibited the highest degree of potency amongst the derivatives, displaying a GI₅₀ value of 0.7 nM, which makes it 1700-fold more potent than cisplatin (1200 nM) and nearly 7-fold more potent than our lead complex, 56MESS (4.6 nM) in this cell line. Notably, in the ADDP-resistant ovarian variant cell line, 4 (6 nM) was found to be almost 4700-fold more potent than cisplatin. Reduction reaction experiments were also undertaken, along with studies aimed at determining the complexes' solubility, stability, lipophilicity, and reactive oxygen species production.

Potent Chlorambucil-Platinum(IV) Prodrugs

The DNA-alkylating derivative chlorambucil was coordinated in the axial position to atypical cytotoxic, heterocyclic, and non-DNA coordinating platinum(IV) complexes of type, [Pt^IV(H_L)(A_L)(OH)₂](NO₃)₂ (where H_L is 1,10-phenanthroline, 5-methyl-1,10-phenanthroline or 5,6-dimethyl-1,10-phenanthroline, A_L is 1S,2S-diaminocyclohexane). The resultant platinum(IV)-chlorambucil prodrugs, PCLB, 5CLB, and 56CLB, were characterized using high-performance liquid chromatography, nuclear magnetic resonance, ultraviolet-visible, circular dichroism spectroscopy, and electrospray ionization mass spectrometry. The prodrugs displayed remarkable antitumor potential across multiple human cancer cell lines compared to chlorambucil, cisplatin, oxaliplatin, and carboplatin, as well as their platinum(II) precursors, PHENSS, 5MESS, and 56MESS. Notably, 56CLB was exceptionally potent in HT29 colon, Du145 prostate, MCF10A breast, MIA pancreas, H460 lung, A2780, and ADDP ovarian cell lines, with GI₅₀ values ranging between 2.7 and 21 nM. Moreover, significant production of reactive oxygen species was detected in HT29 cells after treatment with PCLB, 5CLB, and 56CLB up to 72 h compared to chlorambucil and the platinum(II) and (IV) precursors.

Drivers of Research Outcomes in Developing Countries: The Case of Lebanon

This paper uses a unique dataset from Lebanon, a developing country with unstable political conditions, to explore the drivers of research outcomes. We use the Negative Binomial model to empirically examine the determinants of the total number of publications and single and co-authored articles. The results indicate that males are more likely to publish co-authored papers than females. Moreover, our findings show a quadratic relationship between age and the number of published papers with a peak at the age of 40. After this turning point, the publication rate starts to decrease at an increasing rate. When we run the model by gender, we find that females in large departments tend to publish more co-authored papers. We also find that full professors tend to publish more papers in Q1 and Q2 journals, while associate professors have more papers in Q2 and Q3 journals.