Michał Chojnacki

Tryptophan (TRP) and its metabolites are involved in numerous physiological and pathological processes within the skin. They may influence melanoma biology, but their role remains insufficiently understood. This study investigated the effects of TRP, anthranilic acid (AA), and cinnabarinic acid (CBA) in melanoma cells in vitro and their potential interaction with the B-Raf proto-oncogene, serine/threonine kinase (BRAF) inhibitor vemurafenib. A375, G361, and SK-MEL-3 melanoma cell lines and a THP-1-derived macrophage model were used. Cell proliferation and metabolic activity were assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, migration using a scratch assay, and cell-cycle distribution by flow cytometry. Western blotting was used to analyze selected signaling proteins. Reactive oxygen species (ROS) and nitric oxide (NO) production were evaluated. Bioinformatic analyses investigated associations between BRAF and genes related to tryptophan metabolism and the kynurenine pathway. All compounds showed dose-dependent antiproliferative effects, with prolonged exposure increasing efficacy. TRP and AA increased G0/G1 cell-cycle arrest, whereas CBA increased the G2/M population. TRP also reduced A375 cell migration. All three compounds enhanced the antiproliferative effect of vemurafenib, with CBA showing the strongest effect (approximately 20%). Western blot analysis indicated modulation of p21 expression and ERK1/2 phosphorylation, suggesting implications for cell cycle and stress signaling pathways. Moreover, conditioned medium from A375 cells exposed to tested compounds affected cell viability, ROS, and NO production in THP-1-derived macrophages. TRP and its metabolites may be considered potential supportive agents for melanoma BRAF-targeted therapy. However, further in vivo studies are needed to clarify their therapeutic value and to elucidate the underlying molecular mechanisms.

Introduction and objective: Hypersensitivity pneumonitis (HP) is a chronic immune-mediated interstitial lung disease driven by persistent antigen exposure, macrophage activation, and progressive lung remodelling. Macrophage-derived transforming growth factor beta (TGF-β) plays a key role in...

Introduction and objective: Endometrial cancer involves uncontrolled cell proliferation and cell cycle dysregulation. Natural compounds, such as microalgae-derived extracts, are being studied as potential chemopreventive agents. The aim of the study is to assess the effects of Chlorella...

Our earlier studies have revealed the beneficial impact of vitamin D3 (VD3) metabolites on the development of pulmonary fibrosis in a murine model of hypersensitivity pneumonitis (HP). Despite the discovery of the great antifibrotic potential of both the bioactive form of VD3, 1,25(OH)₂-VD3 and its direct precursor, 25(OH)-VD3, study designs based on the co-administration of VD3-metabolites and fibrosis-inducers do not reflect the clinical situation. Thus, the presented study aims to examine the effectiveness of therapeutic interventions based on the mentioned inhalations, initiated during the acute phase of HP at the first signs of pulmonary fibrosis. The research was performed using VD3-deficient mice with HP, while VD3-sufficient mice were used as the main control. The data were collected after 28 days of daily exposure of the mice to a fibrosis-inducer (an antigen of Pantoea agglomerans, a well-known etiological factor in HP), with 25(OH)-VD3 or 1,25(OH)₂-VD3 administered daily during the last 14 days of the experiment. The effect of the intervention was monitored by whole-body plethysmography, histological assessment, flow cytometry, RealTime-PCR, and ELISA. Treatment with VD3 metabolites initiated during the acute phase of HP alleviated the disease courses and restored respiratory function, thanks to inhibition of pathological extracellular matrix deposition, immune-cell infiltration of lung parenchyma, profibrotic cytokine production, and EMT progression. Despite the discovery of the beneficial features of the investigated VD3-based therapies, none of them caused full recovery in mice with HP. Nevertheless, after verification in additional animal models and a deeper understanding of the underlying molecular mechanisms, the identified beneficial features of the investigated metabolites have the potential to serve as a foundation for future therapies for HP fibrosis.

Although vitamin D3 (VD3) deficiency has been recognized as a harmful agent in several respiratory diseases, the present study is the first one to investigate its influence on the development of hypersensitivity pneumonitis (HP). This research was conducted in a murine model of HP, wherein pulmonary fibrosis was induced by antigen of Pantoea agglomerans. VD3 deficiency was provoked by diet with 10-times less cholecalciferol than feed given to VD3-sufficient mice. Before and after 14 and 28 days of nebulization, lung function was evaluated. Moreover, at indicated time points, lungs were collected and subjected to histological assessment, flow cytometry, gene expression assays, and ELISA. The performed research showed a higher sensitivity of VD3-deficient mice to fibrosis response to P. agglomerans antigen, which was strongly associated with enhanced epithelial-to-mesenchymal transition, the signs of which were over-expression of EMT-transcription factors (Snail2, Zeb1, Zeb2) and mesenchymal cell markers (Cdh2/N-cadherin, Acta2/SMA, Fn1/Fibronectin, Vim/Vimentin). Indicated negative changes in VD3-deficient mice with developed HP were supported by deepening calcitriol deficiency and worsening respiratory functions, including the frequency of breathing, minute volume, total cycle times, expiratory and inspiratory time. Moreover, typical for VD3-deficient mice with HP, there was also an increased influx of immune cells into the lungs (especially neutrophils, macrophages, dendritic cells and lymphocytes Tc), a disturbed cytokine profile with over-production of growth factors favoring fibrosis (FGF2 and TGFβ), and lowered synthesis of several cytokines (IL1β, IL6, IL12, IL4 IL10, IL13). The present study reveals that VD3 deficiency promotes the development of pulmonary fibrosis in the murine model of HP.

Chlorella species are classified as functional food, with great anticancer effects. Despite the huge popularity of Chlorella-based products, there is a lack of evidence showing their usefulness in the prevention and treatment of endometrial cancer. The study presented here aimed to enrich knowledge resources in this area. The chemopreventive effect of water extracts of Chlorella pyrenoidosa was investigated in human endometrial adenocarcinoma HEC-1-B, KLE and EDC cells using MTT, BrdU, LDH, Wound assays, Cell Death Detection ELISA and nuclear double staining. C. pyrenoidosa extract inhibited the metabolic activity, DNA synthesis and migratory capacity of endometrial cancer cells. Moreover, the extract eliminated cancer cells, causing damage to their cell membranes and inducing apoptosis. The cells most resistant to chlorella extract were EDC cells (low grade), while the best response to the treatment was noted in KLE cells (high grade). The performed study revealed the chemopreventive properties of C. pyrenoidosa extract based on inhibition of endometrial cancer cell viability, proliferation and migratory capacity, as well as induction of cytotoxicity and apoptosis. Collected data suggested enhancement of extract chemopreventive properties with increasing advancement and malignancy of cancer cells. Obtained results encourage future clinical research and detailed chemical evaluation to specify the extract’s phytochemical composition.

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.

Glioblastoma multiforme is a highly aggressive intrinsic brain tumor with a very poor survival rate. The main treatment for cancer is surgery combined with postoperative radiotherapy and temozolomide chemotherapy. Since the outcomes of treatment are unsatisfactory, the search for more effective drugs is crucial. Our previous study indicated that mephedrone, a synthetic cathinone, reduced neuron and astrocyte viability and oligodendrocyte proliferation. The aim of the present study was to investigate the effect of mephedrone on selected human glioblastoma (LN-18, LN-229, T98G) and human anaplastic astrocytoma (MOGGCCM) cell lines. The effects of mephedrone on cell viability and proliferation, DNA synthesis, cell cycle progression and the type of cell death were studied. Our results showed that mephedrone possesses potential anticancer activity. The viability and proliferation of all four human glioblastoma and human anaplastic astrocytoma cell lines used were decreased in a concentration-dependent manner. Studies conducted on LN-18 and T98G cells confirmed the significant antiproliferative properties of mephedrone, which reduced DNA synthesis and affected cell cycle progression. Microscopic evaluation supported the antiproliferative effect of the tested compounds. Moreover, substantial cytoplasmic vacuolization in the LN-18 cell line was revealed. This finding may indicate the potential of mephedrone in anticancer therapy.