Maciej Małecki

The role of the SHH gene in prostate cancer cell resistance to paclitaxel

The increased activity of the Sonic Hedgehog (SHH) pathway has been demonstrated in many types of cancer including prostate cancer (PCa). It has been shown that SHH pathway is involved in tumor angiogenesis and in regulation of metabolism of cancer stem cells. The increased activity of the SHH pathway is responsible for generation and maintenance of the multidrug resistance in cancer cells. A key role in the development of this insensitivity to cytotoxic drugs play ATP‐binding cassette (ABC) transporters.

Antibacterial Activity and Cytotoxicity of Silver(I) Complexes of Pyridine and (Benz)Imidazole Derivatives. X-ray Crystal Structure of [Ag(2,6-di(CH2OH)py)2]NO3

Selected aspects of the biological activity of a series of six nitrate silver(I) complexes with pyridine and (benz)imidazole derivatives were investigated. The present study evaluated the antibacterial activities of the complexes against three Gram-negative strains: Pseudomonas aeruginosa ATCC 15442, Escherichia coli ATCC 25922 and Proteus hauseri ATCC 13315. The results were compared with those of silver nitrate, a silver sulfadiazine drug and appropriate ligands. The most significant antibacterial properties were exerted by silver(I) complexes containing benzimidazole derivatives. The cytotoxic activity of the complexes was examined against B16 (murine melanoma) and 10T1/2 (murine fibroblasts) cells. All of the tested silver(I) compounds were not toxic to fibroblast cells in concentration inhibited cancer cell (B16) viability by 50%, which ranged between 2.44–28.65 µM. The molecular and crystal structure of silver(I) complex of 2,6-di(hydroxymethyl)pyridine was determined by single-crystal X-ray diffraction analysis. The most important features of the crystal packing and intermolecular non-covalent interactions in the Ag(I) complex were quantified via Hirshfeld surface analysis.

The Angiogenic Activity of Ascites in the Course of Ovarian Cancer as a Marker of Disease Progression

Ovarian cancer cells are able to create invasive implants in the peritoneum and their growth is directly associated with the angiogenetic potential. This effect is probably stimulated by vascular endothelial growth factor (VEGF) and interleukin-8 (IL-8), which are both found in ascites. The aim of this study was to assess the influence of ascites produced by ovarian cancer on the angiogenesis. Peritoneal fluid was collected from patients with advanced ovarian cancer; cancer cells were separated from CD45+ leukocytes. Angiogenesis was assessed in mice, after intradermal injection of full cellular suspension together with supernatant or phosphate buffered saline, purified cancer cells suspension, or CD45+ leukocytes suspension. The angiogenesis index (AI) was assessed after 72 hours. VEGF and Il-8 were measured in the supernatant and cellular suspension. AI was the highest in the isolated cancer cells suspensions as well in the group stimulated with supernatant. Both VEGF and IL-8 were high in supernatants from ascites rich in cancer cells (>45%). A significant correlation was revealed between IL-8 concentration and AI. We conclude that ascites in patients with advanced ovarian cancer stimulates angiogenesis and this mechanism is dependent mostly on cancer cells activity and enhanced by cooperation with infiltrating leukocytes.

Age‐dependent expression of Nav1.9 channels in medial prefrontal cortex pyramidal neurons in rats

Developmental changes that occur in the prefrontal cortex during adolescence alter behavior. These behavioral alterations likely stem from changes in prefrontal cortex neuronal activity, which may depend on the properties and expression of ion channels. Nav1.9 sodium channels conduct a Na+ current that is TTX resistant with a low threshold and noninactivating over time. The purpose of this study was to assess the presence of Nav1.9 channels in medial prefrontal cortex (mPFC) layer II and V pyramidal neurons in young (20‐day old), late adolescent (60‐day old), and adult (6‐ to 7‐month old) rats. First, we demonstrated that layer II and V mPFC pyramidal neurons in slices obtained from young rats exhibited a TTX‐resistant, low‐threshold, noninactivating, and voltage‐dependent Na+ current. The mRNA expression of the SCN11a gene (which encodes the Nav1.9 channel) in mPFC tissue was significantly higher in young rats than in late adolescent and adult rats. Nav1.9 protein was immunofluorescently labeled in mPFC cells in slices and analyzed via confocal microscopy. Nav1.9 immunolabeling was present in layer II and V mPFC pyramidal neurons and was more prominent in the neurons of young rats than in the neurons of late adolescent and adult rats. We conclude that Nav1.9 channels are expressed in layer II and V mPFC pyramidal neurons and that Nav1.9 protein expression in the mPFC pyramidal neurons of late adolescent and adult rats is lower than that in the neurons of young rats.

Prenyl Ammonium Salts--New Carriers for Gene Delivery: A B16-F10 Mouse Melanoma Model.

Purpose Prenyl ammonium iodides (Amino-Prenols, APs), semi-synthetic polyprenol derivatives were studied as prospective novel gene transfer agents. Methods AP-7, -8, -11 and -15 (aminoprenols composed of 7, 8, 11 or 15 isoprene units, respectively) were examined for their capacity to form complexes with pDNA, for cytotoxicity and ability to transfect genes to cells. Results All the carriers were able to complex DNA. The highest, comparable to commercial reagents, transfection efficiency was observed for AP-15. Simultaneously, AP-15 exhibited the lowest negative impact on cell viability and proliferation—considerably lower than that of commercial agents. AP-15/DOPE complexes were also efficient to introduce pDNA to cells, without much effect on cell viability. Transfection with AP-15/DOPE complexes influenced the expression of a very few among 44 tested genes involved in cellular lipid metabolism. Furthermore, complexes containing AP-15 and therapeutic plasmid, encoding the TIMP metallopeptidase inhibitor 2 (TIMP2), introduced the TIMP2 gene with high efficiency to B16-F10 melanoma cells but not to B16-F10 melanoma tumors in C57BL/6 mice, as confirmed by TIMP2 protein level determination. Conclusion Obtained results indicate that APs have a potential as non-viral vectors for cell transfection.

Rise in antifibrotic and decrease in profibrotic microRNA protect the heart against fibrosis during pregnancy: A preliminary study

BACKGROUND Physiological pregnancy is associated with volume overload. Unlike cardiac pathologies linked with volume overload, such as mitral or aortic regurgitation, pregnancy is thought to be unrelated to fibrosis of the heart. However, changes in the cardiac extracellular matrix during pregnancy remain poorly understood. OBJECTIVES The aim of the study was to examine the expression of 11 microRNAs associated with cardiac fibrosis (miR-21, miR-26a, miR-26b-5p, miR-29b-3p, miR-29c-3p, miR-101a, miR-146a, miR-208a, miR-223 and miR-328) during pregnancy and to compare them with a healthy control group. MATERIAL AND METHODS Six women in singleton pregnancy (30-36 weeks) and 6 non-pregnant women as a control group were included in the study. Each woman underwent an echocardiographic examination, and had blood pressure on both arms measured and a blood sample taken. MicroRNAs expression was analyzed using Custom TaqMan® Array MicroRNA Cards (Applied Biosystems, Foster City, USA). RESULTS Median age of the pregnant women was 34 years (range 25-39 years) and of the control group 32 years (range 29-43 years). Median week of pregnancy was 34 years (range 31-36 years). Most of the examined microRNAs had a lower expression in the pregnancy group (fold change 1.0). CONCLUSIONS In the 3rd trimester of physiological pregnancy, there is a 244% increase in expression of miR-101a and a decrease by 73% in expression of miR-328. Both of these changes can protect against fibrosis during volume overload occurring in physiological pregnancy.

Anticancer activity of a trans-platinum(II) complex of 3-aminoflavone to ovarian cancer cells

OBJECTIVES Cisplatin is a classical anticancer drug used in the treatment of ovarian cancer. Unfortunately, the treatment is associated with numerous adverse effects. Studies concerning new platinum derivatives with less organ toxicity are conducted. The aim of this study was to analyse the effect of a new trans-platinum(II) complex of 3-aminoflavone on the viability and mortality of the cells from OVCAR 3 and CAOV 3 ovarian cancer cell lines and on the expression of the selected genes involved in the process of apoptosis. MATERIAL AND METHODS The viability of ovarian cancer cells and the cytotoxicity of a trans-platinum(II) complex of 3-amino-flavone: [trans-Pt(3-af )₂Cl₂), trans-bis-(3-aminoflavone) dichloridoplatinum(II)] and cisplatin were analysed using a spectrophotometric method with the use of MTT assay and LDH assay. BAX, BCL2, BIRC5 gene expression analysis on mRNA level was conducted with the use of Real-Time PCR method. RESULTS It was observed that parallel to an increase in the concentration of the new complex compound and cisplatin there is a decrease in viability and an increase in mortality of ovarian cancer cells. As a result of exposure to the studied compound and cisplatin, an increased BAX gene expression and decreased BCL2 and BIRC5 gene expression were observed in the studied ovarian cancer cell lines. CONCLUSION Trans-Pt(3-af )₂Cl₂ exhibits anticancer activity towards OVCAR 3 and CAOV 3 ovarian cancer cell lines. The studied complex compound can be considered as a potential anticancer drug.