Comparison of the anti-cancer activity of 5-aminolevulinic acid-mediated photodynamic therapy after continuous wave and pulse irradiation in different histological types of canine mammary sarcoma tumors

Canine mammary sarcoma tumors (CMST) are the most aggressive tumors with poor prognosis in dogs. Due to inadequate treatment options for CMST, recent studies have focused on alternative treatment strategies. We previously determined the optimized protocol of 5-ALA-based photodynamic therapy (PDT) in canine liposarcoma. However, its molecular mechanisms in the treatment of different histological types of CMST remain unclear.In this context, we, for the first time, assessed 5-aminolevulinic acid (5-ALA)-PDT-mediated anti-cancer activity and its molecular mechanism after continuous wave (CW) and pulse radiation (PR) on three different histological types (liposarcoma, chondrosarcoma, and osteosarcoma) of CMST cells by WST-1, Annexin V, ROS, acridine orange/propidium iodide staining, RT-PCR, and western blot analysis.Our findings showed that 5-ALA/PDT significantly suppressed the proliferation of CMST cells (p < 0.01) and induced apoptosis via increased ROS level and overexpression of Caspase-9 and Caspase-3 mRNA and cleaved protein levels in especially liposarcoma and chondrosarcoma cells following CW and PR irradiation at 9 J/cm2. However, the response of CMST cells to 5-ALA was different upon CW and PR irradiation due to differences in their origin.Collectively, our findings provided the first evidence that 5-ALA-based PDT could be used as an alternative treatment strategy, especially liposarcoma and chondrosarcoma. However, further in vitro and in vivo studies are required to elucidate the underlying molecular mechanism of the efficacy of 5-ALA in CMST cells at the molecular level.

Efficacy of 5-aminolevulinic acid-based photodynamic therapy in different subtypes of canine mammary gland cancer cells

Canine mammary gland tumors (CMGTs) are heterogeneous disease and subclassified [sarcomas (S), carcinomas (C), and carcinosarcomas (CS)] according to histopathological differentiation. Photodynamic therapy (PDT) is a promising treatment strategy based on the use of a photosensitizer (PS) activated by light. However, the therapeutic potential of PDT in the treatment of CMGTs has not been investigated, yet. Therefore, the aim of this study was to determine the in vitro protocol of 5-ALA-based-PDT for the treatment of three subtypes of CMGTs, for the first time. The intracellular PpIX florescence intensity was measured for 5-ALA (0.5 and 1 mM). After irradiation with different light doses (6, 9, 12, 18, and 24 J/cm²) for two different modes [continuous wave (CW) and pulse radiation (PR)], the cytotoxic effects of 5-ALA (0.5 and 1 mM) on the subtypes (C, S, and CS) of CMGTs were analyzed by WST-1. Finally, the optimal PDT treatment protocol was validated through Annexin V and AO/EtBr staining. Our results showed that 1 mM 5-ALA for 4-h incubation was the best treatment condition in all subtypes of CMGTs due to higher intracellular PpIX level. After irradiation with different light doses, PR mode was more effective in S primary cells at 9 J/cm². However, a significant decrease in the viability of C and CS cells was detected at 12 /cm² in CW mode (p < 0.05). Additionally, 1 mM 5-ALA induced apoptotic cell death in each subtype of CMGTs. Our preliminary findings suggest that (i) each subtype of CMGTs differentially responds to PDT and (ii) the light dose and mode could play an important role in the effective PDT treatment. However, further studies are needed to investigate the role of the different light sources and PDT-based apoptotic cell death in CMGTs cells.

Single-crystal X-ray structural characterization, Hirshfeld surface analysis, electronic properties, NBO, and NLO calculations and vibrational analysis of the monomeric and dimeric forms of 5-nitro-2-oxindole

The information of interactions is given by RDG versus sign(λ₂)ρ product of the sign of the second largest eigenvalue of electron density Hessian matrix and electron density) investigated by RDG surface analysis.

Crystal structure and Hirshfeld surface analysis of 4-[4-(1H-benzo[d]imidazol-2-yl)phen-oxy]phthalo-nitrile dimethyl sulfoxide monosolvate

This work presents the synthesis and structural characterization of [4-(1H-benzo[d]imidazol-2-yl)phen-oxy]phthalo-nitrile, a phthalo-nitrile derivative carrying a benzimidazole moiety. The compound crystallizes as its dimethyl sulfoxide monosolvate, C₂₁H₁₂N₄O·(CH₃)₂SO. The dihedral angle between the two fused rings in the heterocyclic ring system is 2.11 (1)°, while the phenyl ring attached to the imidazole moiety is inclined by 20.7 (1)° to the latter. In the crystal structure, adjacent mol-ecules are connected by pairs of weak inter-molecular C-H⋯N hydrogen bonds into inversion dimers. N-H⋯O and C-H⋯O hydrogen bonds with R ₂ ¹(7) graph-set motifs are also formed between the organic mol-ecule and the disordered dimethyl sulfoxide solvent [occupancy ratio of 0.623 (5):0.377 (5) for the two sites of the sulfur atom]. Hirshfeld surface analysis and fingerprint plots were used to investigate the inter-molecular inter-actions in the crystalline state.

Synthesis, characterization, and determination of genotoxic effect of a novel dimeric 8-hydroxyquinoline Cd(II) SCN complex

In this study, a Cd(II) complex was synthesized using 8-hydroxyquinoline and thiocyanate as the ligands and structurally characterized with the combination of FTIR, ¹H-NMR, ¹³C-NMR, UV-vis, and MS spectral data. Then, genotoxic effects of the prepared complex were investigated. Genotoxic properties of the dimeric 8-hydroxyquinolinthiocyanatoCd(II) [Cd₂(8Q)₂(SCN)₂] complex synthesized as drug raw material were analyzed in human peripheral blood lymphocytes. Concentrations of 1, 2, 4, 6, and 8 μg/mL [Cd₂(8Q)₂(SCN)₂] were used for 24 and 48  h durations. [Cd₂(8Q)₂(SCN)₂] significantly increased chromosomal aberrations (CAs) at 4, 6, and 8 μg/mL concentrations after a 24- h period and 2 and 4 μg/mL after a 48-h period. [Cd₂(8Q)₂(SCN)₂] significantly decreased the mitotic index (MI) at all concentrations, both at 24 and 48 h. Micronuclei frequency (MN) was not affected by [Cd₂(8Q)₂(SCN)₂] treatment compared with the control. After application for a 48 h period, 6 and 8 μg/mL concentrations showed toxic effects both in chromosomal abnormality and in micronucleus tests. It also decreased the cytokinesis-block proliferation index (CBPI), but this result was statistically significant only at 6 and 8 μg/mL concentrations. In the comet assay (single-cell gel electrophoresis (SCGE)), significant increases in comet tail length, tail moment, and tail intensity were observed at all concentrations. [Cd₂(8Q)₂(SCN)₂] displays clastogenic effect in the concentrations used in human peripheral lymphocytes at chromosomal abnormality, micronucleus tests, and cytokinesis-block proliferation index parameters. Further studies should be conducted in other test systems to evaluate the complete genotoxic potential of [Cd₂(8Q)₂(SCN)₂].

Hydroxyphthalocyanines as potential photodynamic agents for cancer therapy

A series of benzyl-substituted phthalonitriles, substituted at the 3-, 4-, and 4,5-positions, underwent varied condensations with phthalonitrile to give a series of protected (monohydroxy- and polyhydroxyphthalocyaninato)zinc(II) derivatives which were readily cleaved to give several hydroxyphthalocyanines (ZnPc) (phthalocyanine phenol analogues). Their efficacy as sensitizers for the photodynamic therapy (PDT) of cancer was evaluated on the EMT-6 mammary tumor cell line. In vitro, the 2-hydroxy ZnPc (32) was the most active, followed by the 2,3- and 2,9-dihydroxy ZnPc (39 and 45), with the 2,9,16-trihydroxy ZnPc (33) exhibiting the least activity. In vivo, the monohydroxy derivative 32 and the 2,3-dihydroxy derivative 39 were both efficient in inducing tumor necrosis at 1 micromol kg-1, but complete tumor regression was poor, even at 2 micromol/kg. In contrast, the 2,9-dihydroxy isomer 45, at 2 micromol kg-1, induced tumor necrosis in all animals treated, with 75% complete regression. These results underline the importance of the position of the substituents on the Pc macrocycle to optimize tumor response and confirm the PDT potential of the unsymmetrical Pcs bearing functional groups on adjacent benzene rings.