Gallato Zirconium (IV) Phtalocyanine Complex Conjugated with SiO2 Nanocarrier as a Photoactive Drug for Photodynamic Therapy of Atheromatic Plaque.

A new conjugate of gallato zirconium (IV) phthalocyanine complexes (PcZrGallate) has been obtained from alkilamino-modified SiO2 nanocarriers (SiO2-(CH2)3-NH2NPs), which may potentially be used in photodynamic therapy of atherosclerosis. Its structure and morphology have been investigated. The photochemical properties of the composite material has been characterized. in saline environments when exposed to different light sources Reactive oxygen species (ROS) generation in DMSO suspension under near IR irradiation was evaluated. The PcZrGallate-SiO2 conjugate has been found to induce a cytotoxic effect on macrophages after IR irradiation, which did not correspond to ROS production. It was found that SiO2 as a carrier helps the photosensitizer to enter into the macrophages, a type of cells that play a key role in the development of atheroma. These properties of the novel conjugate may make it useful in the photodynamic therapy of coronary artery disease.

Ceramides and sphingosine-1-phosphate as potential markers in diagnosis of ischaemic stroke.

BACKGROUND: Brain imaging in stroke diagnostics is a powerful tool, but one that can fail in more challenging cases, and one that is not particularly useful in identifying transient ischaemic attacks (TIAs). Thus, new reliable blood biomarkers of cerebral ischaemia are constantly sought. OBJECTIVE: We studied the potential usefulness of sphingolipids (SFs) as biomarkers of acute ischaemic stroke and TIA. MATERIAL AND METHODS: Levels of individual ceramide species and sphingosine-1-phosphate (Sph-1-P) in blood serum of patients with acute ischaemic stroke, TIA, and age-matched neurological patients without cerebral ischaemia, were assessed by tandem mass spectrometry liquid chromatography (LC- MS / MS). RESULTS: We found significant increases of several sphingolipid levels, with particularly strong elevations of Cer-C20:0 in patients with acute stroke. Cer-C24:1 was the only ceramide species to decrease as a result of acute stroke. Moreover, its levels inversely correlated with the number of days after stroke onset, suggesting that Cer-C24:1 is an independent parameter related to the course of stroke. To increase the sensitivity of sphingolipid-based tests in stroke diagnostics, we calculated the values of ratios of Sph-1-P / individual ceramide species and Cer-C24:1 individual ceramide species. We found several ratios significantly changed in stroke patients. Two ratios, Sph-1-P / Cer-C24:1 and Cer-C24:0 / Cer-C24:1, presented especially strong increments in patients with acute stroke. Moreover, Sph-1-P / Cer-C24:1 values were augmented in TIA patients. CONCLUSION: Serum SFs could be good candidates to be ischaemic stroke biomarkers. We have identified two SF ratios, Sph-1-P / Cer-C24:1 and Cer-C24:0 / Cer-C24:1, with strong diagnostic potential in ischaemic stroke. We found Sph-1-P / Cer-C24:1 ratio to be possibly useful in TIA diagnostics, also in the long term after ischaemic incidence.

Sorafenib in Combination with Betulinic Acid Synergistically Induces Cell Cycle Arrest and Inhibits Clonogenic Activity in Pancreatic Ductal Adenocarcinoma Cells.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most deadly cancers in the world due to late diagnosis and poor response to available treatments. It is important to identify treatment strategies that will increase the efficacy and reduce the toxicity of the currently used therapeutics. In this study, the PDAC cell lines AsPC-1, BxPC-3, and Capan-1 were treated with sorafenib and betulinic acid alone and in combination. We examined the effect of combined treatments on viability (MTS test), proliferation and apoptosis (annexin V staining), cell cycle arrest (PI staining), alterations in signaling pathways (Western blotting), and colony-forming ability. The combination of sorafenib with betulinic acid inhibited the viability and proliferation of PDAC cells without the induction of apoptosis. The antiproliferative effect, caused by G2 cell cycle arrest, was strongly associated with increased expression of p21 and decreased expression of c-Myc and cyclin D1, and was induced only by combined treatment. Additionally, decreased proliferation could also be associated with the inhibition of the P13K/Akt and MAPK signaling pathways. Importantly, combination treatment reduced the colony-forming ability of PDAC cells, as compared to both compounds alone. Collectively, we showed that combined treatment with low concentrations of sorafenib and betulinic acid had the capacity to inhibit proliferation and abolish clonogenic activity in PDAC cell lines.

An Anti-Inflammatory Azaphenothiazine Inhibits Interferon ß Expression and CXCL10 Production in KERTr Cells.

An azaphenothiazine derivative, 6-chloroethylureidoethyldiquino[3,2-b;2',3'-e][1,4]thiazine (DQT), has recently been shown to exhibit immunosuppressive activities in mouse models. It also inhibited the expression of CXCL10 at the protein level, at non-toxic concentrations, in the culture of KERTr cells treated with double-stranded RNA, poly(I:C). In this report, we demonstrated that DQT inhibits the transcription of the CXCL10 gene. Although CXCL10 is an IFNγ-inducible protein, we found that the CXCL10 protein was induced without the detectable release of IFNγ or IκB degradation. Hence, we concluded that IFNγ or NFκB was not involved in the regulation of the CXCL10 gene in KERTr cells transfected with poly(I:C), nor in the inhibitory activity of DQT. On the other hand, we found that IFNß was induced under the same conditions and that its expression was inhibited by DQT. Kinetic analysis showed that an increase in IFNß concentrations occurred 4⁻8 h after poly(I:C) treatment, while the concentration of CXCL10 was undetectable at that time and started to increase later, when IFNß reached high levels. Therefore, DQT may be regarded as a new promising inhibitor of IFNß expression and IFNß-dependent downstream genes and proteins, e.g., CXCL10 chemokine, which is implicated in the pathogenesis of autoimmune diseases.

Synergistic activity of sorafenib and betulinic acid against clonogenic activity of non-small cell lung cancer cells.

The highly selective multi-targeted agent sorafenib is an inhibitor of a number of intracellular signaling kinases with anti-proliferative, anti-angiogenic and pro-apoptotic effects in various types of tumors, including human non-small cell lung cancer (NSCLC). Betulin displays a broad spectrum of biological and pharmacological properties, including anticancer and chemopreventive activity. Combination of drugs with different targets is a logical approach to overcome multilevel cross-stimulation among key signaling pathways in NSCLC progression. NSCLC cell lines, A549, H358 and A427, with different KRAS mutations, and normal human peripheral blood lymphocyte cells, were treated with sorafenib and betulinic acid alone and in combination. We examined the effect of different combined treatments on viability (MTS test), proliferation and apoptotic susceptibility based on flow cytometry, alterations in signaling pathways by western blotting and colony-forming ability. The combination of sorafenib with betulinic acid had a strong effect on the induction of apoptosis of different NSCLC cell lines. In addition, this combination was not toxic for human peripheral blood lymphocytes. Combination treatment changed the expression of proteins involved in the mitochondrial apoptosis pathway and induced apoptotic death by caspase activation. Importantly, combination treatment with low drug concentrations tremendously reduced the colony-forming ability of A549, H358 and A427 cells, as compared to both compounds alone. In this study, we showed that combination therapy with low concentrations of sorafenib and betulinic acid had the capacity to induce high levels of cell death and abolish clonogenic activity in some NSCLC cell lines regardless of KRAS mutations.

Opioid Receptors in Psoriatic Skin: Relationship with Itch.

Psoriasis is an inflammatory immunogenetic skin disease, often accompanied by itch. Opioid receptors are known regulators of itch sensation in the central nervous system. In the brain, µ-opioid receptors may potentiate itch, while activation of κ-opioid receptors may reduce or even alleviate itch; however, the role of opioid receptors in itch perception in the skin is poorly understood. To further elucidate the role of opioid receptors in the neurobiology of psoriatic itch, punch biopsies of non-lesional and lesional skin of patients with psoriasis and healthy controls were studied. Real-time polymerase chain reaction and immunofluorescence microscopy were used to detect opioid receptor genes and protein expression, respectively. The OPRK1/κ-opioid receptor pathway was found to be downregulated in lesional skin of psoriasis, correlating positively with itch sensation. In contrast, the OPRM1/µ-opioid receptor system was uniformly expressed by epidermal keratinocytes in all analysed groups. These findings suggest that imbalance of epidermal opioid receptors may result in disordered neuroepidermal homeostasis in psoriasis, which could potentiate transmission of itch.

Long-lasting reduction in clonogenic potential of colorectal cancer cells by sequential treatments with 5-azanucleosides and topoisomerase inhibitors.

BACKGROUND: The currently approved therapies fail in a substantial number of colorectal cancer (CRC) patients due to the molecular heterogeneity of CRC, hence new efficient drug combinations are urgently needed. Emerging data indicate that 5-azanucleosides are able to sensitize cancer cells to the standard chemotherapeutic agents and contribute to overcoming intrinsic or acquired chemoresistance. METHODS: CRC cells with different genetic backgrounds (HCT116, DLD-1, HT-29) were sequentially treated with 5-azanucleosides and topoisomerase inhibitors. The combined effects of these two drug classes on cell viability, apoptosis, signaling pathways, and colony formation were investigated. RESULTS: Here, we demonstrate that pretreatment with DNA demethylating agents, 5-aza-2'-deoxycytidine and 5-azacytidine, sensitizes CRC cells to topoisomerase inhibitors (irinotecan, etoposide, doxorubicin, mitoxantrone), reducing cell viability and clonogenicity and increasing programmed cell death more effectively than individual compounds at the same or even higher concentrations. 5-Azanucleosides did not cause considerable immediate toxic effects as evaluated by analysis of cell viability, apoptosis, DNA damage (γH2A.X), and endoplasmic reticulum (ER) stress (CHOP). However, 5-azanucleosides exerted long-lasting effects, reducing cell viability, changing cell morphology, and affecting phosphoinositide 3-kinase (PI3-kinase)/Akt signaling pathway. We found that a single exposure to 5-azanucleosides is sufficient to induce long-lasting sensitization to topoisomerase inhibitors. The combinatorial, but not separate, treatment with low doses of 5-aza-2'-deoxycytidine (0.1 µM) and etoposide (0.5 µM) caused a long-lasting (almost 70 days) reduction in clonogenic/replating ability of DLD-1 cells. CONCLUSIONS: These results suggest that sequential treatments with DNA demethylating agents and topoisomerase inhibitors may exert clinically relevant anticancer effects.

Advanced Glycation End-Products in Blood Serum-Novel Ischemic Stroke Risk Factors? Implication for Diabetic Patients.

New predictors of ischemic incidents are constantly sought since they raise the awareness of patients and their doctors of stroke occurrence. The goal was to verify whether Advanced Glycation End Products (AGEs), in particular AGE10, could be one of them. The AGE10 measurement was conducted using a non-commercial ELISA assay in the blood serum of neurological patients without cerebrovascular event (n = 24), those with transient brain attack (TIA) (n = 17), and severe ischemic stroke (n = 35). Twice as many of the people with TIA or severe stroke presented high AGE10 serum concentrations compared to the patients with other neurological conditions (χ2 = 8.2, p = 0.004; χ2 = 8.0, p = 0.005, respectively). The risk of ischemic incident was significantly risen in people with higher levels of AGE10 (OR = 6.5, CI95%: 1.7-24.8; OR = 4.7, CI95%: 1.5-14.5 for TIA and stroke subjects, respectively). We observed a positive correlation (r = 0.40) between high AGE10 levels and diabetes. Moreover, all the diabetic patients that had a high AGE10 content experienced either a severe ischemic stroke or TIA. The patients with high levels of AGE10 exhibited higher grades of disability assessed by the NIHSS scale (r = 0.35). AGE10 can be considered a new biomarker of ischemic stroke risk. Patients with diabetes presenting high AGE10 levels are particularly prone to the occurrence of cerebrovascular incidents.

The interplay between epigenetic silencing, oncogenic KRas and HIF-1 regulatory pathways in control of BNIP3 expression in human colorectal cancer cells.

Bcl-2/adenovirus E1B-19kDa-interacting protein 3 (BNIP3) is an important mediator of cell survival and a member of the Bcl-2 family of proteins that regulate programmed cell death and autophagy. We have previously established a link between the expression of oncogenic HRas and up-regulation of BNIP3 and the control of autophagy in cancer cells. However, in view of varied expression of BNIP3 in different tumor types and emerging uncertainties as to the role of epigenetic silencing, oncogenic regulation and the role of BNIP3 in cancer are still poorly understood. In the present study we describe profound effect of KRas on the expression of methylated BNIP3 in colorectal cancer cells and explore the interplay between HIF-1, hypoxia pathway and oncogenic KRas in this context. We observed that BNIP3 mRNA remains undetectable in aggressive DLD-1 cells harboring G13D mutant KRAS and HT-29 colorectal cancer cells unless the cells are exposed to demethylating agents such as 5-aza-2'-deoxycytidine. Following this treatment BNIP3 expression remains uniquely dependent on the Ras activity. We found that hypoxia or pharmacological activation of HIF-1 alone contributes to, but is not sufficient for efficient induction of BNIP3 mRNA transcription in cells lacking mutant KRas activity. The up-regulation of BNIP3 by KRas in this setting is mediated by the MAPK pathway, and is attenuated by the respective inhibitors (PD98059, U0126). Thus, we demonstrate the novel mechanism where activity of Ras is essential for 5-aza-2'-deoxycytidine-mediated BNIP3 expression. Moreover, we found that 5-aza-2'-deoxycytidine-mediated or enforced up-regulation of BNIP3 in DLD-1 cells results in KRas-dependent resistance to 5-Fluorouracil.

Novel genistein derivatives induce cell death and cell cycle arrest through different mechanisms.

Genistein is a natural compound belonging to isoflavone family of secondary plant metabolites, characterized by pleiotropic biological activity. Here we present the results of a study on new analogs and polysaccharide complexes of genistein as potent antiproliferative and cell death-inducing agents. Most potent were 2 analogs (i.e., IFG-027 and IFG-043) and 2 complexes (i.e., SPG-G and XG-G), which had higher or similar antiproliferative activity in comparison to genistein. However, these 2 analogs decreased the number of cells in G2/M phase in contrast to genistein and SPG-G complex. Genistein analogs, IFG-027 and IFG-043, and also SPG-G complex decreased mitochondrial membrane potential and induced the externalization of phosphatidylserine to the extracellular membrane site, which indicates the induction of apoptosis. Interestingly, genistein and its analogs induced caspase 3-activation supporting apoptotic mechanism of cell death but SPG-G supported caspase 3-independent apoptosis. XG-G complex probably did not induce cell death through the apoptotic pathway, as we did not find the externalization of phosphatidylserine and activation of caspase-3. After the treatment of HL-60 cells with genistein, SPG-G and XG-G formation of acidic vesicular organelle (AVO) was detected. In contrast, in the cells that were treated with genistein analogs IFG-027 and IFG-043, AVO formation was not observed.

[Autophagy and BNIP3 protein in tumorogenesis]. / Autofagia i bialko BNIP3 w nowotworach.

Autophagy is a process necessary for maintaining cell homeostasis in physiological conditions, as well as during certain stresses like nutrients or oxygen deprivation. Autophagy also plays an essential role in tumorigenesis. It prevents cell transformation, but on the other hand, autophagy enables existing cancer cells to adapt to harmful conditions and increased glucose demand, supports maintaining of cellular metabolism and accelerates tumor growth. Among others, it refers to Ras-transformed cells. Recent research unveiled BNIP3 protein as one of the key players involved in autophagy. Although BNIP3 is classified as proapoptotic member of BH3-only subfamily, its proapoptotic activity is questionable. However, BNIP3 demonstrates ability to induce or stimulate autophagy and its specific variant--mitophagy. This paper aims to summarize the existing body of knowledge related to the role of BNIP3 in autophagy, as well as the importance of this process in tumorigenesis. In particular, we emphasize the relation between autophagy and BNIP3 expression induced by Ras oncogene.

Heterogeneity of Extracellular Vesicles and Particles: Molecular Voxels in the Blood Borne "Hologram" of Organ Function, Disfunction and Cancer.

Extracellular vesicles (EVs) and particles (EPs) serve as unique carriers of complex molecular information with increasingly recognized roles in health and disease. Individual EVs/EPs collectively contribute to the molecular fingerprint of their producing cell, reflecting its identity, state, function and phenotype. This property is of particular interest in cancer where enormous heterogeneity of cancer cells is compounded by the presence of altered stromal, vascular and immune cell populations, which is further complicated by systemic responses elicited by the disease in individual patients. These diverse and interacting cellular compartments are dynamically represented by myriads of EVs/EPs released into the circulating biofluids (blood) during cancer progression and treatment. Current approaches of liquid biopsy seek to follow specific elements of the EV/EP cargo that may have diagnostic utility (as biomarkers), such as cancer cell-derived mutant oncoproteins or nucleic acids. However, with emerging technologies enabling high-throughput EV/EP analysis at a single particle level, a more holistic approach may be on the horizon. Indeed, each EV/EP carries multidimensional information (molecular "voxel") that could be integrated across thousands of particles into a larger and unbiased landscape (EV/EP "hologram") reflecting the true cellular complexity of the disease, along with cellular interactions, systemic responses and effects of treatment. Thus, the longitudinal molecular mapping of EV/EP populations may add a new dimension to crucial aspects of cancer biology, personalized diagnostics, and therapy.

H-Ras increases release of sphingosine resulting in down-regulation of TSP-1 in non-transformed cells.

Tumour progression is continuously driven by a sequence of genetic events. The presence of mutant or activated Ras proteins represents an interesting paradigm for the investigation of oncogene-dependent induction of tumour angiogenesis. These genes are widely distributed in human cancers. Previously we have shown that cells harbouring mutant H-Ras release soluble unidentified factor(s) associated with lowered expression of an angiogenesis inhibitor - Thrombospondin-1 - (TSP-1) in adjacent normal tissue. In this study, we have addressed the question as to whether or not introduction of the H-ras oncogene leads to increased production of sphingosine. To assess the amount of sphingosine in conditioned media, we developed a technique based on sphingolipid isolation and GC-MSMS detection of specific silylated sphingosine derivatives. Cells harbouring mutant H-Ras, release significant amounts of sphingosine in contrast to normal isogenic cells or premalignant cells. Increased concentration of sphingosine in conditioned media was correlated with their ability to down-regulate the expression of TSP-1. Moreover, medium collected in the presence of U0126, an inhibitor of MAPK kinase (MEK), contained undetectable amounts of sphingosine and had no ability to down-regulate TSP-1 expression. Overall, our studies suggest a H-Ras-dependent mechanism of changing the equilibrium of angiogenic factors in favour of induction of angiogenesis, where a central role is played by sphingosine, a low molecular entity. This represents an example of how a mechanism of translating genetic changes within transformed cells could be amplified into a much larger effect involving the tumour parenchyma and stroma, and this could greatly in turn accelerate local tumour growth and metastasis.

The Contrasting Delayed Effects of Transient Exposure of Colorectal Cancer Cells to Decitabine or Azacitidine.

(1) Background: Decitabine and azacitidine are cytosine analogues representing the class of drugs interfering with DNA methylation. Due to their molecular homology and similar clinical application, both drugs are often regarded as interchangeable. Despite their unique mechanism of action the studies designed for observation and comparison of the prolonged activity of these drugs are rare. (2) Methods: The short-time (20-72 h) and long-term (up to 20 days) anti-cancer activity of decitabine and azacitidine has been studied in colorectal cancer cells. We observe the impact on cell culture's viability, clonogenicity, proliferation, and expression of CDKN1A, CCND1, MDM2, MYC, CDKN2A, GLB1 genes, and activity of SA-ß-galactosidase. (3) Results: Decitabine has much stronger anti-clonogenic activity than azacitidine. We show that azacitidine, despite significant immediate toxicity, has negligible long-term effects. Contrary, decitabine, which does not exert initial toxicity, profoundly worsened the condition of the cells over time. On the 13th day after treatment, the viability of cells was decreased and proliferation inhibited. These functional changes were accompanied by up-regulation of expression CDKN1A, CCND1, and CDKN2A genes and increased activation of SA-ß-galactosidase, indicating cellular senescence. (4) Conclusions: Our head-to-head comparison revealed profound differences in the activities of decitabine and azacitidine important in their anti-cancer potential and clinical application. The effects of decitabine need relatively long time to develop. This property is crucial for proper design of studies and therapy concerning decitabine and undermines opinion about the similar therapeutic mechanism and interchangeability of these drugs.

Hypoxia increases the apoptotic response to betulinic acid and betulin in human non-small cell lung cancer cells.

Betulinic acid and betulin show promising activity against cancers cells, but the mechanism of their action is still unclear. In this study, non-small cell lung cancer (NSCLC) cell lines: A549, H358 and NCI-H1703 were treated with betulinic acid and betulin under normoxic and hypoxic conditions as hypoxia is critically involved in the response of solid tumors to chemotherapy. The treatment inhibits viability and proliferation of NSCLC cells. The anti-proliferative effect was induced by G1 cell cycle arrest with increased p21 expression and decreased cyclin D1 and cyclin B1 expression. Additionally, downregulation of p-GSK3ß activity and the Wnt/ß-catenin pathway were also observed under hypoxia. We found that hypoxia increased apoptosis in NSCLC cells. Cell death was associated with changes in the expression of proteins involved in the mitochondrial apoptosis pathway and induction of apoptotic death by caspase activation. Additionally, hypoxia exposure deregulated HIF-1α and p53 expression levels. Importantly, treatment with betulinic acid and betulin reduced colony-forming ability under normoxia, however, only betulinic acid reduced clonogenic activity under hypoxia. Our findings that betulinic acid increases apoptotic cell death and clonogenic activity under hypoxic conditions reveal new attractive strategies for treating hypoxic cancer tumors, such as NSCLC.

A newly established canine NK-type cell line and its cytotoxic properties.

We established a canine natural killer (NK)-type cell line called CNK-89 derived from a dog with NK cell neoplasia. Immunophenotyping analysis showed positive staining for CD5, CD8, CD45, CD56, CD79a and NKp46, while negative for CD3, CD4, CD14, CD20, CD21, CD34, Thy1, IgG, IgM and MHCII. Polymerase chain reaction analysis revealed the presence of CD56, NKG2D, NKp30, NKp44, NKp46 and perforin, but the absence of CD16, Ly49 and granzyme B mRNA. Treating CNK-89 cells with IL-2 did not change the expression of activating receptors, TNFα and IFNγ secretion and cytotoxic activity, however, treatment with IL-12 alone or in combinations with IL-15, IL-18 and IL-21 caused an increase in granzyme B and CD16 mRNA, IFNγ secretion and cytotoxic properties of the CNK-89 cell line.

Anti-Inflammatory Activity of a Cyclic Tetrapeptide in Mouse and Human Experimental Models.

A cyclic tetrapeptide Pro-Pro-Pheß3ho-Phe (4B8M) was tested for immunosuppressive activity and potential therapeutic utility in several in vitro and in vivo mouse and human models. The tetrapeptide was less toxic for mouse splenocytes in comparison to cyclosporine A (CsA) and a parent cyclolinopeptide (CLA). The tetrapeptide demonstrated potent anti-inflammatory properties in antigen-specific skin inflammatory reactions to oxazolone and toluene diisocyanate as well to nonspecific irritants such as salicylic acid. It also inhibited inflammatory processes in an air pouch induced by carrageenan. In addition, 4B8M proved effective in amelioration of animal models corresponding to human diseases, such as nonspecific colon inflammation induced by dextran sulfate and allergic pleurisy induced by ovalbumin (OVA) in sensitized mice. The tetrapeptide lowered expression of EP1 and EP3 but not EP2 and EP4 prostaglandin E2 (PGE2) receptors on lipopolysaccharide-stimulated Jurkat T cells and ICAM-1 expression on human peripheral blood mononuclear cells (PBMC). Its anti-inflammatory property in the carrageenan reaction was blocked by EP3 and EP4 antagonists. In addition, 4B8M induced an intracellular level of PGE2 in a human KERTr keratinocyte cell line. In conclusion, 4B8M is a low toxic and effective inhibitor of inflammatory disorders with potential therapeutic use, affecting the metabolism of prostanoid family molecules.

Therapeutic effects of an azaphenothiazine derivative in mouse experimental colitis.

Phenothiazines represent a class of compounds of potential therapeutic utility. In this report we evaluated therapeutic value of an azaphenothiazine derivative, 6-acetylaminobutyl-9-chloroquino[3,2-b]benzo[1,4]thiazine (QBT), given intragastrically, in the model of dextran sodium sulfate-induced colitis in C57BL/6 mice using 5-aminosalicylic acid (5-ASA) as a reference drug. Colitis symptoms such as body weight loss, diarrhea and hematochezia (blood in stool) were observed and registered and disease activity index (DAI) was calculated. In addition, weight and cell numbers in the lymphatic organs and histological parameters of the colon wall were analyzed. The effects of QBT on viability of colon epithelial cell lines were also determined. We showed that weight and cell number of draining mesenteric lymph nodes were lower in mice treated with QBT in comparison to their control counterparts. The number of thymocytes, drastically reduced in control mice, was elevated in mice treated with the compounds with a significant effect of 5-ASA. In addition, an abnormal composition of blood cell types was partially corrected in these groups. Histological analysis of the colon revealed that the pathological changes were partially normalized by QBT and even to a higher degree by 5-ASA. In conclusion we demonstrated a therapeutic efficacy of the compound in amelioration of local and systemic pathological changes associated with chemically-induced colitis in mice. A possible mechanism of action of the compound is discussed.

[BNIP3 as an atypical representative of the Bcl-2 protein family. Part 1: BNIP3, a regulator of non-apoptotic programmed cell death]. / BNIP3 jako nietypowy przedstawiciel rodziny Bcl-2. Czesc 1: BNIP3 - regulator nieapoptotycznej programowanej smierci komórek.

BNIP3 is classified as a member of the Bcl-2 protein family that regulates programmed cell death and of the BH3-only protein subfamily as it only contains one BH domain. However, the transmembrane domain of BNIP3 is involved in at least some of its pro-apoptotic functions. Although there are some similarities between BNIP3 and other BH3-only proteins, for example the ability to interact with anti-apoptotic Bcl-2 proteins and to induce cytochrome c release from mitochondria, BNIP3 is undoubtedly distinct in regard to its activity and regulatory mechanisms. Not only can BNIP3 activate apoptosis, but also, or perhaps first of all, it can activate necrosis-like cell death due to its direct interaction with the mitochondrial membrane. BNIP3 is also involved is autophagy, but its role in this process is not yet clearly understood. It is possible that the induction or stimulation of autophagy by this protein can simultaneously inhibit apoptosis, for example in cardiac myocytes. In some cells, BNIP3 is sequestered in the nucleus, where it also acts as an anti-apoptotic factor, namely as a repressor of AIF transcription. This activity may enable tumor cells to achieve resistance to chemotherapeutics. Understanding BNIP3 functions and regulatory mechanisms can point to new molecular targets in the treatment of cancer and ischemic heart or brain diseases.

[BNIP3 as an atypical representative of the Bcl-2 protein family. Part 2: Regulation of the expression and activity of BNIP3 protein and its role in tumorigenesis]. / BNIP3 jako nietypowy przedstawiciel rodziny Bcl-2. Czesc 2: Regulacja ekspresji i aktywnosci BNIP3 oraz jego rola w chorobie nowotworowej.

BNIP3 belongs to the Bcl-2 protein family that regulates programmed cell death. It is the only known pro-apoptotic protein expressed during hypoxia and this effect is determined by the HIF-1 responsive element in the bnip3 promoter. However, there is evidence that hypoxia is not a sufficient factor to activate BNIP3; possible cell death dependent on this protein occurs as a result of secondary effects of oxygen deprivation, such as acidosis. BNIP3 expression is also regulated by other factors, such as E2F-1, NF-kappaB, and Rb during hypoxia and nitrogen oxide during normoxia. Posttranslational modifications also seem to be essential for BNIP3 activity, but their actual significance is still unclear. Phosphorylation of BNIP3 by PKC promotes its accumulation under hypoxic conditions, but phosphorylation by CK2 can accelerate its degradation. In turn, glycosylation and interactions with anti-apoptotic Bcl-2 proteins suppress BNIP3 activity. Our knowledge about the role of BNIP3 protein in tumor progression is incomplete. It seems to be dependent on the stage of tumor progression. Tumor cells evolved multiple mechanisms of silencing BNIP3 expression or activity and promoter methylation is one of the most frequently observed among them