Search Results (203)

Background: The increased incidence of malignant melanoma is observed in patients with Parkinson’s disease. Methods: The anti-proliferative effects of carbidopa and rasagiline on four human malignant melanoma cell lines (A375, SK-MEL28, FM55P and FM55M2) were determined in MTT assay. The interaction profiles of rasagiline in combinations with cisplatin (CDDP) and mitoxantrone (MTX) in four human melanoma cell lines (A375, SK-MEL28, FM55P and FM55M2) were assessed by means of the isobolographic analysis in the MTT test; Results: Rasagiline, but not carbidopa, produced clear-cut anti-proliferative effects on various melanoma cell lines. The median inhibitory concentrations (IC₅₀ values) of rasagiline in the MTT were 280.69 µM for A375, 402.89 µM for SK-MEL28, 349.44 µM for FM55P, and 117.45 µM for FM55M2, respectively. The experimentally-derived selectivity index for rasagiline ranged from 8.22 to 28.18. Flow cytometry assay revealed, in two melanoma cell lines (FM55P and A375), a significant increase in the number of cells in the G0/G1 (up to 76.48% and 75.46% for cell lines, respectively), accompanied by a decrease in the percentage of cells in the S phase (decrease to 9.91% and 10.83% for cell lines, respectively), which may indicate potential cytostatic properties of rasagiline. The combinations of rasagiline with CDDP (at the fixed-ratio of 1:1) exerted either antagonistic interactions (p < 0.05) in the A375 and SK-MEL28, or additive interactions, with a tendency toward antagonism in the FM55P and FM55M2 cell lines in the MTT test. In contrast, the combinations of rasagiline with MTX (ratio of 1:1) produced either synergistic interaction (p < 0.05) in the FM55P cell line or additive interactions with a tendency toward synergy in the FM55M2, SK-MEL28, and A375 cell lines in the MTT test. Conclusions: Rasagiline combined with MTX exerted the most desirable synergistic interactions in relation to the anti-proliferative effects in four malignant melanoma cell lines, as assessed isobolographically. In contrast, rasagiline should not be combined with CDDP during the treatment of malignant melanoma due to the antagonistic interactions in the MTT assay. Full article

Background: Quercetin is a flavonoid found in various dietary sources. It is a prodrug converted by overexpressed tyrosinase in melanoma into an active o-quinone that suppresses tumour growth. However, injected quercetin is rapidly cleared from the tumour site. Method: Our study aimed to enhance quercetin’s efficacy through nanoencapsulation using biodegradable nanocapsules, which were tested in both mouse and human melanoma cell lines in 2D and 3D models. Results: Nanoencapsulation achieved sustained release and improved bioavailability. In mouse 2D cultures, quercetin nanocapsules (Q-nanos) reduced cell viability to 28%, compared with 46% for free quercetin (Q-only) (p < 0.05). In 3D cultures simulating in vivo conditions, Q-nanos reduced viability to 43%, showing significant anti-melanoma activity, while Q-only resulted in 72% viability (p > 0.05 vs. control). A similar trend was observed in human melanotic melanoma, where both Q-nanos and Q-only were effective compared with the controls, with Q-nanos demonstrating superior tumour inhibition (p < 0.05). Conclusions: These findings show the superior efficacy of nanoencapsulated quercetin over free quercetin. Nanoencapsulation prolonged quercetin’s bioavailability, enhanced tumour regression, and addressed limitations associated with the rapid clearance of free quercetin. Full article

Aldehyde dehydrogenase 2 (ALDH2) is a crucial detoxifying enzyme that eliminates toxic aldehydes. ALDH2 deficiency has been linked to various human diseases, including certain cancers. We have previously reported ALDH2 downregulation in human melanoma tissues. Here, we further investigated the biological significance of ALDH2 downregulation in this malignancy. Analysis of TCGA dataset revealed that low ALDH2 expression correlates with poorer survival in metastatic melanoma. Examination of human metastatic melanoma cell lines confirmed that most had ALDH2 downregulation (ALDH2-low) compared to primary melanocytes. In contrast, a small subset of metastatic melanoma cell lines exhibited normal ALDH2 levels (ALDH2-normal). CRISPR/Cas9-mediated ALDH2 knockout in ALDH2-normal A375 cells promoted tumor growth and MAPK/ERK activation. Given the pivotal role of MAPK/ERK signaling in melanoma and cellular response to acetaldehyde, we compared A375 with ALDH2-low SK-MEL-28 and 1205Lu cells. ALDH2-low cells were intrinsically resistant to BRAF and MEK inhibitors, whereas A375 cells were not. However, A375 cells acquired resistance upon ALDH2 knockout. Furthermore, melanoma cells with acquired resistance to these inhibitors displayed further ALDH2 downregulation. Our findings indicate that ALDH2 downregulation contributes to melanoma progression and therapy resistance in BRAF-mutated human metastatic melanoma cells, highlighting ALDH2 as a potential prognostic marker and therapeutic target in metastatic melanoma. Full article

Background/Objectives: PAX3 is a transcription factor that drives melanoma progression by promoting cell growth, migration, and survival, while inhibiting cellular terminal differentiation. However, known PAX3 target genes are limited and cannot fully explain the wide impact of PAX3 function. The PAX3 protein can regulate DNA through two separate binding domains, the Paired Domain (PD) and Homeodomain (HD), which bind different DNA motifs. It is not clear if these two domains bind and work together to regulate genes and if they promote all or only a subset of downstream cellular events. Methods: PAX3 direct downstream targets were identified using Cleavage Under Targets & Release Using Nuclease (CUT&RUN) assays in SK-MEL-5 melanoma cells. PAX3-binding genomic regions were identified through MACS2 peak calling, and peaks were categorized based on the presence of PD and/or HD binding sites (or neither) through HOMER motif analysis. The peaks were further characterized as Active, Primed, Poised, Repressed, or Closed based on ATAC-seq data and CUT&RUN for histone Post-Translational Modifications H3K4me1, H3K4me3, H3K27me3, and H3K27Ac. Results: This analysis revealed that most of the PAX3 binding sites in the SK-MEL-5 cell line were primarily through the PD and connected to Active genes. Surprisingly, PAX3 does not commonly act as a repressor in SK-MEL-5 cells. Pathway analysis identified genes involved with transcription, RNA modification, and cell growth. Peaks located in distal enhancer elements were connected to genes involved in neuronal growth, function, and signaling. Conclusions: Our results reveal novel PAX3 regulatory regions and putative genes in a melanoma cell line, with a predominance of PAX3 PD binding on active sites. Full article

Melanoma is one of the most aggressive and fatal cancers; however, effective and long-lasting treatment options for melanoma continue to be sought after due to the development of resistance mechanisms to the currently available therapies. Background: The K-homology-type splicing regulatory protein (KSRP) is an RNA-binding regulatory protein that binds to the AU-rich elements at the 3′-UTR of target mRNAs. Prior studies have demonstrated that KSRP plays a crucial role in the post-transcriptional regulation of gene expression in human melanoma. Subsequently, in this study, we further examined the role of KSRP in cell migration, colony formation, apoptosis, and tumorigenicity of human melanoma. Methods: KSRP was knocked down in two different human melanoma cell lines: A375 and SK-MEL-28, using lenti-shRNA techniques. By doing so, we studied the effects of KSRP inhibition on cell migration, colony formation, proliferation, apoptosis, and tumorigenicity in these melanoma cell lines. Results: We observed a significant decrease in cell migration, colony formation, proliferation, and tumorigenicity, while also observing a substantial increase in apoptosis in the KSRP knock down melanoma cell lines. Conclusions: Our data establishes that KSRP plays a vital role in cell migration, colony formation, proliferation, apoptosis, and tumorigenicity in both the A375 and SK-MEL-28 human melanoma cell lines. Full article

The dinuclear platinum(IV) compound {Pt(CH₃)₃}₂(μ-I)₂(μ-adenine) (abbreviated Pt₂ad), obtained by treating cubic [Pt^IV(CH₃)₃(μ₃-I)]₄ with two equivalents of adenine, was isolated and structurally characterized by single crystal X-ray diffraction. The National Cancer Institute Developmental Therapeutics Program’s in vitro sulforhodamine B assays showed Pt₂ad to be particularly cytotoxic against the central nervous system cancer cell line SF-539, and the human renal carcinoma cell line RXF-393. Furthermore, Pt₂ad displayed some degree of cytotoxicity against non-small cell lung cancer (NCI-H522), colon cancer (HCC-2998, HCT-116, HT29, and SW-620), melanoma (LOX-IMVI, Malme-3M, M14, MDA-MB-435, SK-MEL-28, and UACC-62), ovarian cancer (OVCAR-5), renal carcinoma (A498), and triple negative breast cancer (BT-549, MDA-MB-231, and MDA-MB-468) cells. Although anticancer studies involving some adenine platinum(II) compounds have been reported, this study marks the first assessment of the anticancer activity of an adenine platinum(IV) complex. Full article

Background and Objectives: Cutaneous melanoma (CM) poses a continuous challenge in oncology due to the developing resistance to available treatments. Doxorubicin (DOX) is noted as one of the most effective chemotherapeutics, although associated toxicity and resistance limit its use in CM treatment. Consequently, DOX has become a promising candidate for combination therapies targeting this neoplasm. Genistein (GEN) gathered significant attention due to its anti-neoplastic properties and ability to enhance the effects of DOX against several cancers, yet this association remains underexplored in CM. Therefore, this study investigated the combination therapy regimen comprising GEN and DOX in terms of anti-melanoma activity and safety profile. Materials and Methods: The in vitro experiments were performed on SK-MEL-28 and HaCaT cells. Cell viability was determined using MTT assay. Cell morphology and confluence were inspected microscopically. Nuclear and cytoskeletal aspects were assessed via immunofluorescence. Apoptosis and oxidative stress were quantified through caspase activity and intracellular reactive oxygen species (ROS) production, respectively. The irritant effect was evaluated on the chorioallantoic membrane. Results: The results revealed that the combination of GEN 10 µM with DOX (0.5 and 1 µM) provided augmented cytotoxic events (e.g., reduced cell viability, altered cell morphology and confluence, apoptotic-like impairments in nuclear shape and cytoskeletal network, increased caspases-3/7 and -9 activity, and elevated ROS) in SK-MEL-28 cells, compared to individual treatments, and exerted a strong synergistic interaction. Simultaneously, GEN 10 µM efficiently surpassed the toxic effects (e.g., viability and confluence loss, hypertrophy, and cytoskeletal condensation) of DOX (0.5 and 1 µM) in HaCaT cells. In ovo, GEN 10 µM + DOX 1 µM treatment was classified as non-irritant. Conclusions: These findings stand as one of the first contributions revealing the beneficial therapeutic interplay between GEN and DOX at physiologically achievable concentrations that resulted in elevated anti-tumor properties in CM cells and alleviated toxicity in keratinocytes. Full article

A series of 3-azabicyclo[3.1.0]hexanes and cyclopropa[a]pyrrolizidines spiro-fused to acenaphthylene-1(2H)-one and aceanthrylene-1(2H)-one frameworks have been studied for their in vitro antiproliferative activity against human erythroleukemia (K562), cervical carcinoma (HeLa), melanoma (Sk-mel-2), osteosarcoma (U2OS), as well as murine melanoma (B16) cell lines. Using confocal microscopy, it was found that cultivation with the tested spiro-fused compounds led to the disappearance of stress fibers (granular actin was distributed diffusely in the cytoplasm in up to 56% of treated cells) and decrease in filopodia-like deformations (up to 69% after cultivation), which indirectly suggests a decrease in cell motility. The human melanoma cell line scratch test showed that these cells lose their ability to move after cultivation with the tested spiro-fused compounds and do not fill the scratched strip. This was also supported by docking simulations with actin-related targets (PDB ID: 8DNH, 2Q1N). Using flow cytometry, the impact on the mitochondrial membrane potential showed that the tested compounds led to a significant increase in the number of cells with decreased mitochondrial membrane potential from 10% for the control up to 55–80% for the cyclopropa[a]pyrrolizidine adducts. The obtained results support the antitumor effect of the tested spiro-compounds and encourage the extension of the study in order to improve their anticancer activity as well as reduce their toxicological risks. Full article

Vemurafenib is a BRAF (rapidly accelerated fibrosarcoma B-type)-targeted therapy used to treat patients with advanced, unresectable melanoma. It inhibits the MAPK (mitogen-activated protein kinase)/ERK (extracellular signal-regulated kinase) pathway and tumor proliferation in BRAF^V600E-mutated melanoma cells. Resistance to vemurafenib has been reported in melanoma patients due to secondary NRAS (neuroblastoma RAS viral oncogene homolog) mutations, which lead to paradoxical MAPK pathway activation and tumor proliferation. However, the impact of this paradoxical activation on mitochondrial dynamics and function in NRAS-mutated melanoma is unclear. Here, we investigated the effects of vemurafenib on NRAS^Q61R-mutated melanoma cells, focusing on mitochondrial dynamics and function. As expected, vemurafenib did not exhibit cytotoxicity in SK-MEL-147 NRAS^Q61R-mutated melanoma cells, even after 72 h of incubation. However, it significantly enhanced the MAPK/ERK signaling through paradoxical activation, accompanied by decreased expression of mitochondrial fusion proteins and activation of the fission protein DRP1 (dynamin-related protein 1), leading to small, rounded mitochondrial morphology. These observations were corroborated by transcriptome data obtained from NRAS-mutated melanoma patients, showing MFN1 (mitofusin 1) and OPA1 (optic atrophy 1) downregulation and DNM1L (DRP1 gene) upregulation. Interestingly, inhibition of mitochondrial fission with mdivi-1 or modulation of oxidative phosphorylation via respiratory chain inhibition or uncoupling significantly sensitized NRAS^Q61R-mutated melanoma cells to vemurafenib. Despite vemurafenib’s low cytotoxicity in NRAS-mutated melanoma, targeting mitochondrial dynamics and/or oxidative phosphorylation may offer a promising strategy for combined therapy. Full article

Chemoresistance remains one of the major obstacles to cancer treatment. The search for specific molecules that could improve cancer treatment has become one of the objectives of biomedical research. Identifying new natural molecules to enhance chemotherapy treatment or improve sensitization to conventional therapies has become a key objective. Here, we evaluated the effect of Xanthohumol (XN) extracted from hop on SKMEL-28 melanoma cells and their sensitization to vemurafenib (VEM) treatment. We measured the XN effect on cell viability and apoptosis. We also assessed the effect of XN on membrane fluidity and membrane cholesterol levels. Finally, we studied the impact of XN on cell sensitization to VEM. Here, we showed that XN reduced SKMEL-28 cell viability through an apoptotic mechanism. Our results demonstrated the potential role of XN in sensitizing cancer cells to VEM with a less toxic effect on non-tumor cells. A study of XN’s molecular mechanism showed that XN was able to induce cholesterol depletion and increased fluidity in SKMEL-28 cancer cells. This leads to an increase in VEM incorporation. Here, we describe the importance of the strategy to modulate membrane fluidity by XN in order to significantly improve anticancer therapy. Full article

Background/Objectives: Rice bran oil (RBO) is rich in phytochemical compounds and has many pharmaceutical applications. This work evaluated the regenerative potential of nanofibers incorporating RBO, focusing on their efficacy in tissue engineering and dermatological formulations. The main objective was to investigate the impact of RBO on SK-MEL-28 melanoma cell migration and wound closure through an in vitro healing assay. In addition, the biocompatibility and cell adhesion properties of the nanofibers were examined. Methods: The study employed cell culture techniques and field emission gun scanning electron microscopy (FEG-SEM) investigation. RBO was tested at different concentrations (0.5%, 1%, 5%, or 10%), both in isolation and incorporated into nanofibers. Cell migration was assessed through a wound-healing assay, while cell adhesion to the nanofibers was assessed using FEG-SEM. Statistical analyses were conducted to assess the significance of the findings. Results: Higher cell migration was achieved with 5% (p < 0.002) and 10% (p < 0.05) RBO nanofibers compared to the control and isolated RBO. The biocompatibility study found cell adhesion capability, highlighting the potential of these nanofibers for tissue engineering applications. Conclusions: Our results showed enhanced SK-MEL-28 cell migration and wound closure with RBO-incorporated nanofibers compared to isolated RBO. Biocompatibility was confirmed, suggesting potential for tissue engineering. Our findings indicate that the incorporation of RBO into nanofibers improves their oxidative stability, which is essential for preserving their phytochemical compounds and their beneficial effects on human skin cells in vitro. Full article

This study investigated the antiproliferative activity of three classes of benzo[f]pyrrolo[1,2-a]quinoline azatetracyclic derivatives. All compounds were screened against 60 cancer cell lines at a single dose of 10 μM. When we compared the activity of the three classes of azatetracyclic derivatives (azide, monobrominated and dibrominated), we found that the dibrominated compounds were less active, while the azides were the most active molecules. Compounds 3b and 5a, showing the best growth inhibition profile of all the drugs evaluated, were selected for the second stage of a full five-dose testing. According to the results of the in vitro screening, compounds 3b and 5a exhibit good to moderate anticancer activity (in micromolar range) against all nine cancer sub-panels, with compound 5a being more selective than compound 3b. Both compounds presented better activity than phenstatin on T–47D breast cancer cells, with compound 3b also being more active on SK–MEL–28 melanoma cells, while compound 5a was more active than phenstatin on COLO 205 colon cancer cells. As for the probable mechanism of action, the benzoquinoline derivatives could act as PI5P4Kα and PI5P4Kβ inhibitors or topoisomerase II inhibitors. Full article

Background: Melanoma is the most aggressive and lethal skin cancer that affects thousands of people worldwide. Ruthenium complexes have shown promising results as cancer chemotherapeutics, offering several advantages over platinum drugs, such as potent efficacy, low toxicity, and less drug resistance. Additionally, anthraquinone derivatives have broad therapeutic applications, including melanoma. Objectives: Thus, two new ruthenium complexes with 1-hydroxy-9,10-anthraquinone were obtained: trans-[Ru(HQ)(PPh₃)₂(bipy)]PF₆ (1) and cis-[RuCl₂(HQ)(dppb)] (2), where HQ = 1-hydroxy-9,10-anthraquinone, PPh₃ = triphenylphospine, bipy = 2,2′-bipyridine, PF₆ = hexafluorophosphate, and dppb = 1,4-bis(diphenylphosphine)butane. Methods: The complexes were characterized by infrared (IR), UV–vis, ¹H, ¹³C{¹H}, and ³¹P{¹H} NMR spectroscopies, molar conductivity, cyclic voltammetry, and elemental analysis. Furthermore, density functional theory (DFT) calculations were performed. Results: Compound (2) was determined by single-crystal X-ray diffraction, which confirms the bidentate coordination mode of HQ through the carbonyl and phenolate oxygens. Additionally, DNA-binding experiments yielded constants of 10⁵ M⁻¹ (Kb = 6.93 × 10⁵ for (1) and 1.60 × 10⁵ for (2)) and demonstrate that both complexes can interact with DNA through intercalation, electrostatic attraction, or hydrogen bonding. Conclusions: The cytotoxicity profiles of the compounds were evaluated in human melanoma cell lines (SK-MEL-147, CHL-1, and WM1366), revealing greater cytotoxic activity for (1) on the CHL-1 cell line with an IC₅₀ of 14.50 ± 1.09 µM. Subsequent studies showed that (1) inhibits the proliferation of CHL-1 cells and induces apoptosis, associated at least in part with the pro-oxidant effect and cell cycle arrest at the G1/S transition. Full article

Background: A series of spiro-fused heterocyclic compounds containing cyclopropa[a]pyrrolizidine-2,3′-oxindole and 3-spiro[3-azabicyclo[3.1.0]-hexane]oxindole frameworks were synthesized and studied for their in vitro antiproliferative activity against human erythroleukemia (K562), cervical carcinoma (HeLa), acute T cell leukemia (Jurkat), melanoma (Sk-mel-2) and breast cancer (MCF-7) as well as mouse colon carcinoma (CT26) cell lines. Methods: Cell proliferation was evaluated in vitro by MTS assay. Confocal microscopy was used to study actin cytoskeleton structure and cell motility. Cell cycle analysis was evaluated by flow cytometry. Results: It was found that compounds 4, 8, 18 and 24 showed antiproliferative activity against the Jurkat, K-562, HeLa and Sk-mel-2 cell lines with IC₅₀ ranging from 2 to 10 μM (72 h). Evaluation of the impact on cell cycle progression showed that the tested compounds achieved significant cell-cycle perturbation with a higher accumulation of cells in the SubG1 and G0/G1 phases of the cell cycle, in comparison to the negative control. I Incubation with tested compounds led to the disappearance of stress fibers (granular actin was distributed diffusely in the cytoplasm in up to 38% of treated HeLa cells) and changes in the number of filopodia-like deformations (reduced from 93% in control cells to 64% after treatment). The impact on the Sk-mel-2 cell actin cytoskeleton structure was even greater: granular actin was distributed diffusely in the cytoplasm in up to 90% of treated cells while the number of filopodia-like deformations was reduced by up to 23%. A scratch test performed on the human melanoma cell line showed that these cells did not fill the scratched strip and lose their ability to move under treatment. Conclusions: The obtained results support the antitumor effect of the tested spiro-compounds and encourage the extension of this study in order to improve their anticancer activity as well as reduce their toxicological risks. Full article

The migratory and invasive capabilities of melanoma cells contribute to metastasis. Therefore, targeting the genes driving these processes can support melanoma therapy. Rab27A and Rab27B contribute to tumor formation progression in many types of cancer through various mechanisms, including the secretion of small extracellular vesicles (sEVs). We explored the role of these GTPases in melanoma cell functioning in three RAB27A knockout (KO) cell lines (A375, DMBC12, and SkMel28) and a double RAB27A/B KO A375 cell line. The loss of RAB27A impaired the migration and invasion of DMBC12 and SkMel28 cells; however, the behavior of highly aggressive A375 cells was unaffected. The RAB27A/B double knockout moderately decreased the migratory capacity of A375 cells without disturbing their invasiveness. Additionally, the silencing of RAB27A did not affect the number and mean size of the sEVs, despite some alterations in the protein content of the vesicles. Both Rab27 isoforms can, at least partially, act independently. The potential role of Rab27A in the functioning of melanoma cells depends on the individual character of the cell line, but not on its basal expression, and seems to be unrelated to the secretion of sEVs. Full article