Inhibiting centrosome clustering reduces cystogenesis and improves kidney function in autosomal dominant polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD) is a monogenic disorder accounting for approximately 5% of patients with renal failure, yet therapeutics for the treatment of ADPKD remain limited. ADPKD tissues display abnormalities in the biogenesis of the centrosome, a defect that can cause genome instability, aberrant ciliary signaling, and secretion of pro-inflammatory factors. Cystic cells form excess centrosomes via a process termed centrosome amplification (CA), which causes abnormal multipolar spindle configurations, mitotic catastrophe, and reduced cell viability. However, cells with CA can suppress multipolarity via "centrosome clustering," a key mechanism by which cells circumvent apoptosis. Here, we demonstrate that inhibiting centrosome clustering can counteract the proliferation of renal cystic cells with high incidences of CA. Using ADPKD human cells and mouse models, we show that preventing centrosome clustering with 2 inhibitors, CCB02 and PJ34, blocks cyst initiation and growth in vitro and in vivo. Inhibiting centrosome clustering activates a p53-mediated surveillance mechanism leading to apoptosis, reduced cyst expansion, decreased interstitial fibrosis, and improved kidney function. Transcriptional analysis of kidneys from treated mice identified pro-inflammatory signaling pathways implicated in CA-mediated cystogenesis and fibrosis. Our results demonstrate that centrosome clustering is a cyst-selective target for the improvement of renal morphology and function in ADPKD.

Ultrastructure expansion microscopy (U-ExM) of mouse and human kidneys for analysis of subcellular structures

Ultrastructure expansion microscopy (U-ExM) involves the physical magnification of specimens embedded in hydrogels, which allows for super-resolution imaging of subcellular structures using a conventional diffraction-limited microscope. Methods for expansion microscopy exist for several organisms, organs, and cell types, and used to analyze cellular organelles and substructures in nanoscale resolution. Here, we describe a simple step-by-step U-ExM protocol for the expansion, immunostaining, imaging, and analysis of cytoskeletal and organellar structures in kidney tissue. We detail the critical modified steps to optimize isotropic kidney tissue expansion, and preservation of the renal cell structures of interest. We demonstrate the utility of the approach using several markers of renal cell types, centrioles, cilia, the extracellular matrix, and other cytoskeletal elements. Finally, we show that the approach works well on mouse and human kidney samples that were preserved using different fixation and storage conditions. Overall, this protocol provides a simple and cost-effective approach to analyze both pre-clinical and clinical renal samples in high detail, using conventional lab supplies and standard widefield or confocal microscopy.

Cep120 is essential for kidney stromal progenitor cell growth and differentiation

Mutations in genes that disrupt centrosome structure or function can cause congenital kidney developmental defects and lead to fibrocystic pathologies. Yet, it is unclear how defective centrosome biogenesis impacts renal progenitor cell physiology. Here, we examined the consequences of impaired centrosome duplication on kidney stromal progenitor cell growth, differentiation, and fate. Conditional deletion of the ciliopathy gene Cep120, which is essential for centrosome duplication, in the stromal mesenchyme resulted in reduced abundance of interstitial lineages including pericytes, fibroblasts and mesangial cells. These phenotypes were caused by a combination of delayed mitosis, activation of the mitotic surveillance pathway leading to apoptosis, and changes in both Wnt and Hedgehog signaling that are key for differentiation of stromal cells. Cep120 ablation resulted in small hypoplastic kidneys with medullary atrophy and delayed nephron maturation. Finally, Cep120 and centrosome loss in the interstitium sensitized kidneys of adult mice, causing rapid fibrosis after renal injury via enhanced TGF-β/Smad3-Gli2 signaling. Our study defines the cellular and developmental defects caused by loss of Cep120 and aberrant centrosome biogenesis in the embryonic kidney stroma.

The Role of Bcl-2 and Beclin-1 Complex in "Switching" between Apoptosis and Autophagy in Human Glioma Cells upon LY294002 and Sorafenib Treatment

BACKGROUND

Gliomas are the most malignant tumors of the central nervous system. One of the factors in their high drug resistance is avoiding programmed death (PCD) induction. This is related to the overexpression of intracellular survival pathways: PI3K-Akt/PKB-mTOR and Ras-Raf-MEK-ERK. Apoptosis and autophagy are co-existing processes due to the interactions between Bcl-2 and beclin-1 proteins. Their complex may be a molecular "toggle-switch" between PCD types. The aim of this research was to investigate the role of Bcl-2:beclin-1 complex in glioma cell elimination through the combined action of LY294002 and sorafenib.

METHODS

Drug cytotoxicity was estimated with an MTT test. The type of cell death was evaluated using variant microscopy techniques (fluorochrome staining, immunocytochemistry, and transmission electron microscopy), as well as the Bcl-2:beclin-1 complex formation and protein localization. Molecular analysis of PCD indicators was conducted through immunoblotting, immunoprecipitation, and ELISA testing. SiRNA was used to block Bcl-2 and beclin-1 expression.

RESULTS

The results showed the inhibitors used in simultaneous application resulted in Bcl-2:beclin-1 complex formation and apoptosis becoming dominant. This was accompanied by changes in the location of the tested proteins.

CONCLUSIONS

"Switching" between apoptosis and autophagy using PI3K and Raf inhibitors with Bcl-2:beclin-1 complex formation opens new therapeutic perspectives against gliomas.

Impaired centrosome biogenesis in kidney stromal progenitors reduces abundance of interstitial lineages and accelerates injury-induced fibrosis

Defective centrosome function can disrupt embryonic kidney development, by causing changes to the renal interstitium that leads to fibrocystic disease pathologies. Yet, it remains unknown how mutations in centrosome genes impact kidney interstitial cells. Here, we examined the consequences of defective centrosome biogenesis on stromal progenitor cell growth, differentiation and fate. Conditional deletion of Cep120 , a ciliopathy gene essential for centrosome duplication, in the stromal mesenchyme resulted in reduced abundance of pericytes, interstitial fibroblasts and mesangial cells. This was due to delayed mitosis, increased apoptosis, and changes in Wnt and Hedgehog signaling essential for differentiation of stromal lineages. Cep120 ablation resulted in hypoplastic kidneys with medullary atrophy and delayed nephron maturation. Finally, centrosome loss in the interstitium sensitized kidneys of adult mice, causing rapid fibrosis via enhanced TGF-β/Smad3-Gli2 signaling after renal injury. Our study defines the cellular and developmental defects caused by centrosome dysfunction in embryonic kidney stroma.

Highlights

Defective centrosome biogenesis in kidney stroma causes:Reduced abundance of stromal progenitors, interstitial and mesangial cell populationsDefects in cell-autonomous and paracrine signalingAbnormal/delayed nephrogenesis and tubular dilationsAccelerates injury-induced fibrosis via defective TGF-β/Smad3-Gli2 signaling axis.

Involvement of PI3K Pathway in Glioma Cell Resistance to Temozolomide Treatment

The aim of the study was to investigate the anticancer potential of LY294002 (PI3K inhibitor) and temozolomide using glioblastoma multiforme (T98G) and anaplastic astrocytoma (MOGGCCM) cells. Apoptosis, autophagy, necrosis, and granules in the cytoplasm were identified microscopically (fluorescence and electron microscopes). The mitochondrial membrane potential was studied by flow cytometry. The activity of caspases 3, 8, and 9 and Akt was evaluated fluorometrically, while the expression of Beclin 1, PI3K, Akt, mTOR, caspase 12, and Hsp27 was determined by immunoblotting. SiRNA was used to block Hsp27 and PI3K expression. Cell migration and localization of Hsp27 were tested with the wound healing assay and immunocytochemistry, respectively. LY294002 effectively diminished the migratory potential and increased programmed death of T98G and MOGGCCM. Autophagy was dominant in MOGGCCM, while apoptosis was dominant in T98G. LY294002 with temozolomide did not potentiate cell death but redirected autophagy toward apoptosis, which was correlated with ER stress. A similar effect was observed after blocking PI3K expression with siRNA. Transfection with Hsp27 siRNA significantly increased apoptosis related to ER stress. Our results indicate that inhibition of the PI3K/Akt/mTOR pathway sensitizes glioma cells to apoptosis upon temozolomide treatment, which was correlated with ER stress. Hsp27 increases the resistance of glioma cells to cell death upon temozolomide treatment.

Coumarins modulate the anti-glioma properties of temozolomide

In the recent years, coumarin bioactive compounds have been identified to posess anticancer properties. Therefore, the aim of the present study was to investigate for the first time the efficacy of osthole, umbelliferone, esculin, and 4-hydroxycoumarin, alone and in combination with Temozolomide, in the elimination of deadly brain tumors, anaplastic astrocytoma (AA) and glioblastoma multiforme (GBM) cells via programmed death. Our results indicated that osthole, umbelliferone, esculin, and 4-hydroxycoumarin initiated mainly apoptosis in the T98G and MOGGCCM cells. Osthole was the most effective. It also initiated autophagy in a small percentage of the cell population. The co-incubation with Temozolomide did not increase the pro-apoptotic potential of natural compounds but decreased the level of autophagy in the T98G cells. Apoptosis was associated with reduced mitochondrial membrane potential, activation of caspase 3, inhibition of Bcl-2 expression and the presence of a Bcl-2/Beclin 1. Blocking of Bcl-2 expression resulted in promotion of apoptosis, but not autophagy, in the MOGGCCM and T98G lines. It also sensitized astrocytoma cells, but not GBM, to the combined osthole and TMZ treatment, which was correlated with a reduced level of Beclin 1 and increased expression of caspase 3. Osthole and TMZ, alone and in combination, inhibited the migratory phenotype of the GBM and AA cells. In summary, our results indicated that osthole effectively eliminated glioma cells via apoptosis, what was correlated with Bcl-2/Beclin 1 complex formation. Considering the anti-migratory effect, osthole and Temozolomide display antiglioma potential but it needs further extensive studies.

A Tryptophan Metabolite, 8-Hydroxyquinaldic Acid, Exerts Antiproliferative and Anti-Migratory Effects on Colorectal Cancer Cells

8-Hydroxyquinaldic acid, the end-metabolite of tryptophan, is well-known metal chelator; however, its role in humans, especially in cancer promotion and progression, has not been fully revealed. Importantly, 8-hydroxyquinaldic acid is the analog of kynurenic acid with evidenced antiproliferative activity towards various cancer cells. In this study, we revealed that 8-hydroxyquinaldic acid inhibited not only proliferation and mitochondrial activity in colon cancer HT-29 and LS-180 cells, but it also decreased DNA synthesis up to 90.9% for HT-29 cells and 76.1% for LS-180 cells. 8-Hydroxyquinaldic acid induced changes in protein expression of cell cycle regulators (CDK4, CDK6, cyclin D1, cyclin E) and CDKs inhibitors (p21 Waf1/Cip1, p27 Kip1), but the effect was dependent on the tested cell line. Moreover, 8-hydroxyquinaldic acid inhibited migration of colon cancer HT-29 and LS-180 cells and increased the expression of β-catenin and E-cadherin. Importantly, antiproliferative and anti-migratory concentrations of 8-hydroxyquinaldic acid were non-toxic in vitro and in vivo. We reported for the first time antiproliferative and anti-migratory activity of 8-hydroxyquinaldic acid against colon cancer HT-29 and LS-180 cells.

Quinaldic acid induces changes in the expression of p53 tumor suppressor both on protein and gene level in colon cancer LS180 cells

BACKGROUND

Origin, synthesis and activity of quinaldic acid (QA), proposed derivative of kynurenic acid, have been poorly studied to date. Previously, we have demonstrated the antiproliferative effect of QA in a colon cancer model in vitro. The goal of present study was to verify QA activity to modify the expression of p53 tumor suppressor in colon cancer cells, and to relate it to its cancer cell growth inhibiting activity in vitro.

METHODS

LS180 colon cancer cells possessing the wild type form of p53 were used in the study. Real-time PCR and immunobloting techniques were used to test the expression of p53 at gene and protein level, respectively. Next, immunocytochemistry was used to visualize the localization of p53 protein within the cells. Furthermore, the antiproliferative activity of QA was retested in cells with siRNA silenced P53 gene.

RESULTS

The activity of QA to modify both the expression and phosphorylation of p53 protein as well as the level of P53 gene is shown. Concomitantly, the nuclear and cytoplasmic localization of phospho-p53 protein upon QA treatment is also presented. Moreover, reduced activity of QA in colon cancer cells with silenced p53 expression is observed.

CONCLUSION

QA affects the expression of p53 tumor suppressor, both at gene and protein level. The prominent contribution of p53 to the antiproliferative effect of QA in LS180 colon cancer cells can be suggested.

Lycopene, sulforaphane, quercetin, and curcumin applied together show improved antiproliferative potential in colon cancer cells in vitro

Lycopene, sulforaphane, quercetin, and curcumin, ingredients of daily diet, show significant anticancer and chemopreventive potential; however, no data are available showing thorough evaluation of jointly used phytochemicals on cancer cell proliferation. Here, we compare anticancer potential of mentioned substances applied separately or in combination (as MIX) by measuring mitochondrial activity (MTT test), DNA synthesis (BrdU test) and lactate dehydrogenase release (LDH test) in colon epithelial (CCD841 CoTr), and colon cancer (HT-29, LS174T) cells. Additive inhibitory effect of simultaneously used phytochemicals on cancer cells proliferation has been shown. In epithelial cells, tested combination effectively inhibited mitochondrial activity, but not DNA synthesis. LDH test revealed cytotoxicity of tested mixture against cancer cells without negative effect on normal cells. Furthermore, we demonstrated that MIX enhances antiproliferative effect of common cytostatics: 5-fluorouracil and cisplatin. Presented data suggest chemopreventive potential of the proposed combination of natural substances and their usefulness as adjuvant strategy during chemotherapy. PRACTICAL APPLICATIONS: Colorectal cancer is one of the most common causes of cancer death worldwide. Since its development and progression is strongly correlated with dietary habits, healthy diet as well as supplementation with proved anticancer agents seems to be reasonable strategy of colon cancer prevention and treatment. In the present study, we have focused on four natural compounds abundantly found in daily diet i.e., lycopene, sulforaphane, quercetin, and curcumin, with well established anticancer potential. Their individual and collective impact both on normal colon epithelium cells and colon cancer cells viability, growth, and proliferation was examined. Furthermore, activity of the substances combined as MIX to influence antiproliferative potential of commonly used in colon cancer treatment cytostatics, 5-fluorouracil, and cisplatin was verified. Proposed in the study combination of phytochemicals with experimentally proven antiproliferative activity may propose an effective strategy for prevention and treatment of colon cancer.

Development of the 1,2,4-triazole-based anticonvulsant drug candidates acting on the voltage-gated sodium channels. Insights from in-vivo, in-vitro, and in-silico studies

The treatment of epilepsy remains difficult mostly since almost 30% of patients suffer from pharmacoresistant forms of the disease. Therefore, there is an urgent need to search for new antiepileptic drug candidates. Previously, it has been shown that 4-alkyl-5-substituted-1,2,4-triazole-3-thione derivativatives possessed strong anticonvulsant activity in a maximal electroshock-induced seizure model of epilepsy. In this work, we examined the effect of the chemical structure of the 1,2,4-triazole-3-thione-based molecules on the anticonvulsant activity and the binding to voltage-gated sodium channels (VGSCs) and GABA_A receptors. Docking simulations allowed us to determine the mode of interactions between the investigated compounds and binding cavity of the human VGSC. Selected compounds were also investigated in a panel of ADME-Tox assays, including parallel artificial membrane permeability assay (PAMPA), single cell gel electrophoresis (SCGE) and cytotoxicity evaluation in HepG2 cells. The obtained results indicated that unbranched alkyl chains, from butyl to hexyl, attached to 1,2,4-triazole core are essential both for good anticonvulsant activity and strong interactions with VGSCs. The combined in-vivo, in-vitro and in-silico studies emphasize 4-alkyl-5-substituted-1,2,4-triazole-3-thiones as promising agents in the development of new anticonvulsants.

Quinaldic acid in synovial fluid of patients with rheumatoid arthritis and osteoarthritis and its effect on synoviocytes in vitro

BACKGROUND

Previously, we have demonstrated that kynurenic acid (KYNA), an endogenous metabolite of tryptophan formed along kynurenine pathway, is present in synovial fluid of rheumatoid arthritis (RA) and osteoarthritis (OA) patients. In this study, the goal was to investigate the presence of quinaldic acid (QUDA), a putative metabolite of KYNA, in synovial fluid of RA and OA patients.

METHODS

The effect of QUDA on proliferation and motility of synovial fibroblasts and its interaction with KYNA were determined in vitro. The study was conducted on synovial fluid obtained from 38 patients with RA and 15 patients with OA. QUDA was identified and quantified using the gas chromatography-mass spectrometry (GC-MS) method. In vitro experiments were conducted on rabbit synoviocyte cell line HIG-82.

RESULTS

Presence of QUDA was detected in all 53 samples of synovial fluid. The concentration of QUDA in synovial fluid obtained from patients with RA was 28.6 ± 14.9 pmol/ml, which was lower in comparison with OA 42.3 ± 10.0 pmol/ml. QUDA content positively correlated with the number of tender joints and negatively with the total cell counts determined in synovial fluid of RA patients. It did not correlate with KYNA content. QUDA reduced both proliferation and motility of synoviocytes in a dose-dependent manner. The enhancement of antiproliferative action of QUDA by KYNA was evidenced.

CONCLUSIONS

Data show a local deficit of QUDA in RA patients and suggest its potential role as an endogenous substance controlling synoviocyte viability.

Temozolomide and sorafenib as programmed cell death inducers of human glioma cells

BACKGROUND

Gliomas are aggressive brain tumors with very high resistance to chemotherapy. Therefore, the aim of the present study was to investigate the effectiveness of sorafenib and Temozolomide in elimination of human glioma cells through apoptosis and autophagy.

METHODS

MOGGCCM (anaplastic astrocytoma) and T98G (glioblastoma multiforme) cell lines incubated with sorafenib and/or Temozolomide were used in the experiments. Cell morphology (ER stress, apoptosis, autophagy, and necrosis) was analyzed microscopically while apoptosis and mitochondrial membrane potential were assessed with flow cytometry. Beclin1, LC3, p62, Hsp27, and Hsp72 levels were analyzed by immunoblotting. The activity of caspase 3, 8, and 9 was evaluated fluorometrically. Expression of Hsps was blocked by transfection with specific siRNA.

RESULTS

In MOGGCCM cells, Temozolomide most frequently induced autophagy, which was accompanied by decreased p62 and increased beclin1 and LC3II levels. Sorafenib initiated mainly apoptosis. Additional incubation with Temozolomide, synergistically potentiated the pro-apoptotic properties of sorafenib, but it was mediated in a caspase-independent way. In T98G cells, the effect of the analyzed drugs on programmed cell death induction was different from that in MOGGCCM cells. Sorafenib induced autophagy, while Temozolomide initiated mainly apoptosis. After simultaneous drug application, apoptosis dominated, suggesting synergistic action of both drugs. Inhibition of Hsp27 and Hsp72 expression increased the sensitivity of both cell lines to ER stress and, to a lesser extent, to induction of apoptosis, but not autophagy.

CONCLUSIONS

Sorafenib and Temozolomide applied in combination are potent apoptosis inducers in T98G and MOGGCCM cells. ER stress precedes the elimination. Blocking of Hsp expression has a greater impact on ER stress rather than apoptosis induction.

Kynurenic Acid Induces Impairment of Oligodendrocyte Viability: On the Role of Glutamatergic Mechanisms

Kynurenic acid (KYNA) is an end stage product of tryptophan metabolism with a variety of functions in the human body, both in the central nervous system (CNS) and in other organs. Although its activity in the human brain has been widely studied and effects on neural cells were emphasized, the effect of KYNA on oligodendroglial cells remains unknown. Present study aims at describing the activity of high concentration of KYNA in OLN-93 cells. The inhibition of OLN-93 oligodendrocytes viability by KYNA in a medium with reduced serum concentration has been demonstrated. Although decreased metabolic activity of KYNA treated OLN-93 cells was shown, the cells proliferation was not altered. KYNA treatment did not alter morphology as well as expression level of cell cycle and proliferation regulating proteins. Furthermore, glutamate receptor antagonists and agonists did not alter the inhibitory effect of KYNA on viability of OLN-93 oligodendrocytes. This study contributes to the elucidation of effects of KYNA on oligodendrocytes in vitro, yet further analyses are necessary to explain the mechanisms behind the damage and loss of myelin sheaths.

Synthesis, characterization, and pharmacological evaluation of novel azolo- and azinothiazinones containing 2,4-dihydroxyphenyl substituent as anticancer agents

ABSTRACT

We reported the synthesis and characterization of a series of azolo- and azino[1,3]thiazinones containing the 2,4-dihydroxyphenyl substituent. The compounds were prepared by a new one-step reaction of aryl-modified sulfinylbis[(2,4-dihydroxyphenyl)methanethione]s and the corresponding aminoazolo(azino)carboxamides. Their chemical structures were confirmed by IR, NMR: 1H, 13C, HSQC, and EI-MS spectral data. The compounds inhibited proliferation and viability of lung cancer A549, colon cancer HT-29, and glioma C6 cells in a structure- and concentration-dependent manner. The activity of some analogues was below 10 μmol dm-3 (IC50). Glioma C6 cells were the most sensitive to tested compounds. Generally, the derivatives were not toxic for the skin fibroblast HSF culture. Moreover, some of them exerted a protective effect on the treated normal cells. Evaluation of compound properties in silico showed that they possess significant drug-like characteristics and most of them display a low toxicity.

GRAPHICAL ABSTRACT

Quinaldic acid inhibits proliferation of colon cancer ht-29 cells in vitro: effects on signaling pathways

Quinaldic acid is presumed to be a derivative of kynurenic acid, a tryptophan metabolite with proven antiproliferative activity towards cancer cells in vitro. The aim of present study was to evaluate the activity of quinaldic acid in colon cancer cells. The antiproliferative potential of quinaldic acid was assessed in HT-29, LS180 and Caco-2 cells. Suppression of metabolic activity (IC50 of 0.5mM for HT-29 and LS180 cells, 0.9mM for Caco-2 cells) and DNA synthesis (IC50 of 2.7, 4.3, 2mM for HT-29, LS180 and Caco-2 cells, respectively) were observed in all tested cell lines. It is noteworthy that quinaldic acid in antiproliferative concentrations was non-toxic to normal colon epithelium CCD 841 CoTr cells. Concomitantly, alterations in several signaling pathways in HT-29 cells were observed. Quinaldic acid led to changes in the phosphorylation level of extracellular-signal-regulated kinase (ERK) 1/2, p38, cAMP response element-binding protein (CREB) and Akt (protein kinase B) kinases. Moreover, changes in the CREB transcription factor were also found at the gene expression level. Antiproliferative activity and signaling pathways modulatory potential of quinaldic acid in colon cancer cells in vitro has been stated.

The effect of quercetin and imperatorin on programmed cell death induction in T98G cells in vitro

BACKGROUND

High expression of HSP27 and HSP72 in glioma cells has been closely associated with chemoresistance and decreased sensitivity to programmed cell death induction. Therefore, it is important to devise therapies that effectively target invasive cancer cells by inducing cell death. The aim of our study was to assess the effect of quercetin and imperatorin applied separately and in combinations on the apoptosis and autophagy induction in human T98G cells cultured in vitro.

METHODS

Cell death induction was analyzed by the staining method. The Western blotting technique and fluorimetric measurements of activity were used to assess the expression of marker proteins of apoptosis and autophagy. The specific siRNA transfected method was used for blocking of the expression of HSP27 and HSP72 genes.

RESULTS

The experiments revealed the highest percentage of apoptotic cells after using a 50?M concentration of both compounds. Simultaneous quercetin and imperatorin administration induced apoptosis more effectively than incubation with single drugs. These results were accompanied with decreased HSP27 and HSP72 expression, and a high level of caspase-3 and caspase-9 activity. Autophagy was not observed. Additional experiments were performed on a cell line with blocked Hsp27 and Hsp72 expression and significant increase the sensitivity to apoptosis induction upon quercetin and imperatorin treatment was noticed.

CONCLUSIONS

The present study indicates that quercetin and imperatorin are potent apoptosis inducers, especially when they act synergistically, which may be a promising combination useful in glioma therapy. Our results also demonstrated that blocking the HSP27 and HSP72 gene expression might serve as a therapeutic target for the human brain cancer.

Quercetin and sorafenib as a novel and effective couple in programmed cell death induction in human gliomas

The aim of the present study was to investigate the effect of sorafenib and quercetin on the induction of apoptosis and autophagy in human anaplastic astrocytoma (MOGGCCM) and glioblastoma multiforme (T98G) cell lines. In MOGGCCM cells, sorafenib initiated mainly apoptosis, mediated by the mitochondrial pathway with mitochondrial membrane permeabilization, cytochrome c release to the cytoplasm, and activation of caspase 9 and 3. Additional incubation with quercetin potentiated the pro-apoptotic properties of sorafenib. In T98G cells, autophagy was observed most frequently after the sorafenib treatment. It was accompanied by increased beclin 1 and LC3II expression. Administration of quercetin after the sorafenib treatment resulted in an increased number of autophagic cells. After simultaneous drug application, the level of autophagy was lower in favour of apoptosis. Inhibition of heat shock proteins expression by specific small interfering RNA significantly increased the sensitivity of both the cell lines to induction of apoptosis, but not autophagy. We demonstrated for the first time that sorafenib and quercetin are very effective programmed cell death inducers in T98G and MOGGCCM cells, especially in cells with blocked expression of heat shock proteins.

Apoptosis induction in human glioblastoma multiforme T98G cells upon temozolomide and quercetin treatment

Glioblastoma multiforme is the most aggressive primary brain tumour. At the cellular and molecular levels, several mechanisms responsible for apoptosis or autophagy induction are blocked. Identification of molecular targets stimulating cells to initiate programmed cell death should be performed for therapeutic purposes. A promising solution is the combination of temozolomide and quercetin. The aim of our study was to evaluate the effect of both drugs, applied alone and in combinations, on apoptosis and autophagy induction in human glioblastoma multiforme T98G cells. Our results clearly indicate that quercetin and temozolomide induce apoptosis very significantly, having no effect on autophagy induction. At the molecular level, it was correlated with caspase 3 and 9 activation, cytochrome c release from the mitochondrium and a decrease in the mitochondrial membrane potential. Both drugs are also potent Hsp27 and Hsp72 inhibitors. This suggests that the apoptotic signal goes through an internal pathway. Increased expression of caspase 12 and the presence of several granules in the cytoplasm after temozolomide treatment with or without quercetin preceding appearance of apoptosis may suggest that apoptosis is initiated by ER stress. Additionally, it was accompanied by changes in the nuclear morphology from circular to 'croissant like'.

Expression of matricellular proteins in human uterine leiomyomas and normal myometrium

Growth of human leiomyomas can probably be initiated as a response to injury, in a way similar to the development of keloids. Among many bioactive molecules, which are implicated in tissue repair, a pivotal role is attributed to matricellular proteins. The aim of the current study was to evaluate the immunohistochemical expression of tenascin-C (TNC), thrombospondin-1 (TSP-1), SPARC/osteonectin and tenascin-X (TNX) in human uterine leiomyomas and normal myometrium. Immunostaining was performed on 33 pairs of paraffin-fixed sections and 9 cell-lines derived from uterine leiomyomas and normal myometrium. Fifteen (45.5%) leiomyomas investigated were positive for TNC, whereas all normal myometrial samples were immunonegative (χ²=19.41; p<0.001). Immunostaining for TSP-1 was observed in 20 (60.6%) uterine fibroids and in 12 (36.4%) control samples (χ²=3.88; p<0.05). The expression of SPARC/osteonectin protein was more frequently found in leiomyomas than in normal myometrium, but this difference was not significant. Apart from one fibroid culture and one myometrial culture, all the others revealed strong TNC immunostaining. Expression of TSP-1 and SPARC/osteonectin was weak to moderate in all established cell-lines. None of the tissues or cell lines investigated showed positive staining for TNX. In conclusion, TSP-1 and TNC are likely to play important roles in the pathogenesis of uterine leiomyomas, presumably affecting cell proliferation and/or extracellular matrix deposition.

Neuroprotective activity of 2-amino-1,3,4-thiadiazole derivative 4BrABT--an in vitro study

4BrABT (2-(4-Bromophenylamino)-5-(2,4-dihydroxyphenyl)-1,3,4-thiadiazole) is a compound known for its interesting in vitro anticancer profile. 4BrABT inhibited proliferation and motility of several cancer cell lines in concentrations which were not toxic to normal cells. A major problem associated with cancer chemotherapy, but also caused by environmental factors such as pesticides, is neurotoxicity. Therefore, the aim of the presented study was an in vitro evaluation of the neuroprotective activity of this compound. 4BrABT activity (1-100 μM) was tested in cultures of mouse neurons, rat astrocytes and rat oligodendrocytes. A possible protective action of the compound in different neurodegenerative models, as serum deprivation (SD), excitotoxicity (presence of 500 μM glutamate in culture medium), as well as cisplatin toxicity (astroglia--50 μM and oligodendroglia--100 μM) was investigated. Cell viability in the tested cultures was assessed with the use of LDH and MTT methods. Moreover, 4BrABT ability to prevent the cisplatin-induced apoptosis in astrocyte and oligodendrocyte cultures was analysed after Hoechst 33342 fluorostaining. The obtained results indicate that 4BrABT was not toxic to neurons, astrocytes and oligodendrocytes. Moreover, a decrease in the neuronal LDH level was observed, which may suggest the ability of 4BrABT to act as a trophic agent. Furthermore, the protective action of the studied compound was shown in neuronal cultures exposed to neurotoxic conditions (presence of glutamate and trophic stress) and in cisplatin-treated astrocytes and oligodendrocytes. The expression of anticancer and neuroprotective activity raises hopes for the potential use of 4BrABT as a safe anticancer drug, or neuroprotective agent in chemotherapy-associated neurotoxicity.

Alpha-ketoglutarate (AKG) inhibits proliferation of colon adenocarcinoma cells in normoxic conditions

BACKGROUND AND OBJECTIVE

Alpha-ketoglutarate (AKG), a key intermediate in Krebs cycle, is an important biological compound involved in the formation of amino acids, nitrogen transport, and oxidation reactions. AKG is already commercially available as a dietary supplement and its supplementation with glutamine, arginine, or ornithine alpha-ketoglutarate has been recently considered to improve anticancer immune functions. It is well documented that AKG treatment of Hep3B hepatoma cells in hypoxia induced HIF-alpha (hypoxia-inducible factor) degradation and reduced vascular endothelial growth factor (VEGF) synthesis. Moreover, AKG showed potent antitumor effects in murine tumor xenograft model, inhibiting tumor growth, angiogenesis, and VEGF gene expression. However, the mechanisms of its anticancer activity in normoxia have not been examined so far.

RESULTS

Here, we report that in normoxia, AKG inhibited proliferation of colon adenocarcinoma cell lines: Caco-2, HT-29, and LS-180, representing different stages of colon carcinogenesis. Furthermore, AKG influenced the cell cycle, enhancing the expression of the inhibitors of cyclin-dependent kinases p21 Waf1/Cip1 and p27 Kip1. Moreover, expression of cyclin D1, required in G1/S transmission, was decreased, which accompanied with the significant increase in cell number in G1 phase. AKG affected also one the key cell cycle regulator, Rb, and reduced its activation status.

CONCLUSION

In this study for the first time, the antiproliferative activity of AKG on colon adenocarcinoma Caco-2, HT-29, and LS-180 cells in normoxic conditions was revealed. Taking into consideration an anticancer activity both in hypoxic and normoxic conditions, AKG may be considered as a new potent chemopreventive agent.

Identification of an Hsp90 mutation that selectively disrupts cAMP/PKA signaling in Saccharomyces cerevisiae

The molecular chaperone Hsp90 cooperates with multiple cochaperone proteins as it promotes the folding and activation of diverse client proteins. Some cochaperones regulate the ATPase activity of Hsp90, while others appear to promote Hsp90 interaction with specific types of client proteins. Through its interaction with the adenylate cyclase Cyr1, the Sgt1 cochaperone modulates the activity of the cAMP pathway in Saccharomyces cerevisiae. A specific mutation in yeast Hsp90, hsc82-W296A, or a mutation in Sgt1, sgt1-K360E, resulted in altered transcription patterns genetically linked to the cAMP pathway. Hsp90 interacted with Cyr1 in vivo and the hsc82-W296A mutation resulted in reduced accumulation of Cyr1. Hsp90-Sgt1 interaction was altered by either the hsc82-W296A or sgt1-K360E mutation, suggesting defective Hsp90-Sgt1 cooperation leads to reduced Cyr1 activity. Microarray analysis of hsc82-W296A cells indicated that over 80 % of all transcriptional changes in this strain may be attributed to altered cAMP signaling. This suggests that a majority of the cellular defects observed in hsc82-W296A cells are due to altered interaction with one specific essential cochaperone, Sgt1 and one essential client, Cyr1. Together our results indicate that specific interaction of Hsp90 and Sgt1 with Cyr1 plays a key role in regulating gene expression, including genes involved in polarized morphogenesis.

Kinetic studies of the effects of Temodal and quercetin on astrocytoma cells

The aim of the present study was to investigate the kinetics of the effects exerted by Temodal and quercetin on the survival of the human astrocytoma MOGGCCM cell line. Our results indicate that quercetin was toxic and induced necrosis, whereas Temodal induced autophagy-mediated cell death most effectively. The amount of cell death directly correlated with drug concentration and length of exposure. During combined administration of both drugs, Temodal attenuated the cytotoxic effects of quercetin. Combinations of both drugs were effective in inducing programmed cell death, but the type of cell death was concentration-dependent. Co-administration of Temodal (100 μM) with a low quercetin concentration (5 μM) resulted in a very significant induction of autophagy; however, after treatment with quercetin at a higher concentration (30 μM), apoptosis became the primary mechanism of cell death. The sequence of drug administration was also important. The highest number of dead cells was observed after simultaneous administration of both drugs or after pre-incubation with Temodal followed by treatment with quercetin. Apoptosis was identified through activation of the mitochondrial pathway including cleavage of caspase-3 and release of cytochrome c. Autophagy was identified through increased levels of LC3II. Our results indicate that Temodal and quercetin are synergistic inducers of programmed cell death, better together than applied separately. This drug combination appears to be a potent and promising therapeutic relevant to the treatment of gliomas.

Kynurenic acid synthesis and kynurenine aminotransferases expression in colon derived normal and cancer cells

BACKGROUND

Kynurenic acid (KYNA), a tryptophan metabolite, was found in human saliva, gastric juice, bile, pancreatic juice and mucus of rat small intestine.

METHODS

KYNA content in mucus aspirated from human caecum or colon ascendens and KYNA production in colon epithelial and cancer cells were determined using HPLC. Moreover, biological properties of KYNA and kynurenine aminotransferases (KATs) expression in colon epithelial and colon cancer cells were studied.

RESULTS

Considerably higher KYNA concentration was detected in samples from patients diagnosed with colon carcinoma (269.40 ± 107.00 pmol/ml, N = 4), Adenoma tubulovillosum (200.50 ± 36.72, N = 10) or Adenoma tubulare (243.50 ± 38.09, N = 9) than in control group (82.22 ± 7.61 pmol/ml, N = 30). Moreover, colon epithelium CCD 841 CoTr cells actively synthesized KYNA in a concentration- and time-dependent manner. This process was decreased by aminooxyacetic acid and L-glutamate in opposite to 4-aminopyridine treatment. Interestingly, KYNA production in colon cancer cells (HT-29 1.39 ± 0.27, LS-180 1.18 ± 0.15 and Caco-2 4.21 ± 0.30 pmol/1 x 10(5) cells/2 h) was considerably higher in comparison to normal colon epithelial cells (0.70 ± 0.07 pmol/1 x 10(5) cells/2 h). However, KATs I and II were expressed at similar level in both colon epithelium and cancer cells. Furthermore, KYNA exerted an antiproliferative effect at higher micro- and millimolar concentrations against colon cancer cells with the IC(50) of 0.9, 0.2 and 1.2 mM for HT-29, LS-180 and Caco-2 cells, respectively.

CONCLUSION

Summarizing, this is the first report presenting KYNA synthesis and KAT expression in colon derived normal and cancer cells.

Antiproliferative activity of melanoidins isolated from heated potato fiber (potex) in glioma cell culture model

Potex constitutes a potato fiber preparation widely used as an ingredient to meat and bakery products which thermal treatment results in creation of new compounds. Melanoidins are high molecular weight brown end products of Maillard reaction, and few data presenting tumor cell growth inhibiting activity of melanoidins have been reported. Thus, in present study we utilized water extract of Potex roasted (180 °C for 2 h), whose chemical characterization revealed the presence of melanoidin complexes. Heated Potex extract inhibited C6 glioma cell proliferation in a dose-dependent manner measured by MTT method. High molecular weight components present in initial extract were responsible for stronger antiproliferative effect compared with low molecular weight fraction. Impaired MAPK (mitogen-activated protein kinase) and Akt signaling was found in cells treated with the extract. Moreover, flow cytometry analyses revealed the extract to induce G1/S arrest in glioma cells. Simultaneously, Western blot analysis showed elevated levels of p21 protein with concomitant decrease of cyclin D1. In conclusion, observed antiproliferative activity of melanoidins present in heated Potex was linked to disregulated MAPK and Akt signaling pathways, as well as to cell cycle cessation. These results suggest potential application of Potex preparation as a functional food ingredient and chemopreventive agent.

Temozolomide, quercetin and cell death in the MOGGCCM astrocytoma cell line

The aim of the present study was to investigate the effect of Temozolomide (an alkylating chemotherapeutic agent) and quercetin (natural flavonoid) on cell death in the human astrocytoma cell line MOGGCCM (WHO grade III). Our results indicate that Temozolomide induces autophagy, while quercetin promotes severe necrosis in the cell line in a manner dependent on the drug concentration. We demonstrated for the first time that combinations of both drugs were much more effective in programmed cell death induction in glioma cells. At a low (5muM) drug concentration, quercetin potentiated a pro-autophagic effect of Temozolomide, while after treatment with a higher drug concentration (30muM), autophagy switched to apoptosis. Temozolomide attenuated the toxic effect of quercetin. Apoptosis was mediated by the mitochondrial pathway and the activation of caspase 3 and cytochrome C release, but no changes in caspase 8 expression was observed. It was accompanied by decreased mitochondrial membrane potential and inhibition of Hsp27 and Hsp72 expression. Autophagy was correlated with an increased level of LC3II. Temozolomide and quercetin also inhibited migratory phenotype of MOGGCCM cells and changed the nuclei morphology from a circular to an irregular shape. Our results indicate that quercetin acts in synergy with Temozolomide and when used in combination rather than in separate pharmacological application, both drugs are more effective in programmed cell death induction. Temozolomide administered with quercetin seems to be a potent and promising combination which might be useful in glioma therapy.

Separation of an aqueous extract Inonotus obliquus (Chaga). A novel look at the efficiency of its influence on proliferation of A549 human lung carcinoma cells

Aqueous extract of Inonotus obliquus was hydrolyzed in dilute hydrochloric acid. The products were extracted applying organic solvents, and separated chromatographically on a silica gel-packed column. Eluted fractions were analyzed by means of GC-MS. The presence of hydrocarbons, alcohols, phenols and various carbonyl compounds in analyzed fractions has been detected and quantified. Preliminarily experiments on the influence of certain separated samples on the proliferation of A549 human lung carcinoma cells were performed. Therefore, we hypothesize that the major antiproliferative effects are related to the presence of benzaldehyde, which is a benzyl alcohol metabolite formed in situ in the cells culture with the yield moderated by the presence of trace amounts of "high molecular mass compounds".

The T/G mutation in exon 8 of hMSH2 gene in the sporadic colon cancer patients

The DNA mismatch repair (MMR) system guards against genomic instability, therefore the mutations in the human MMR genes cause the majority of the hereditary nonpolyposis colorectal cancer (HNPCC) and a small percentage of the sporadic colon cancer. hMSH2 is one of MMR genes involved in the correction of mispairing during replication and its mutations are associated with both--microsatellite instability and the hereditary and sporadic colon tumourgenesis. The aim of this study was to analyse the T/G mutation (codon 458) in exon 8 of hMSH2 gene in the sporadic colon cancer cells. We also examined the relationship between the T/G mutation of hMSH2 gene, and the selected prognostic factors such as Dukes' stage, histological grade and lymph node metastasis. We analysed samples of tumour from 75 patients with sporadic colorectal cancers. The mutation in the hMSH2 gene ware determined by the RFLP-PCR. We found T/G mutation in exon 8 of hMSH2 gene in 5 patients (6,7%). There was no statistically significant difference between this mutation and selected clinical parameters. The results of our studies revealed that mutations of hMSH2 gene may lead to development of colorectal cancer. No dependence between the mutation of hMSH2 gene and clinical parameters, suggests that the mutation of hMSH2 gene may have a critical significance for the first steps of carcinogenesis in colon epithelial.

[Genetics analysis of microsatellite instability in patients from hereditary nonpolyposis colorectal cancer (HNPCC) families]

Microsatellite instability (MSI) is due to defective DNA mismatch repair and is characteristic of HNPCC tumours.

THE AIM

The role of MSI in familial predisposition to colorectal cancer was investigated in this study by microsatellite analysis among familial cases.

MATERIAL AND METHODS

PCR-based microsatellite analysis was performed in blood obtained from 30 members from HNPCC families. Blood samples age matched healthy individuals (n = 28) served as control. MSI was studied at five loci containing single- or dinucleotide repeat sequences and mapping to different chromosomal locations: BAT-25 (at locus 4q12), BAT-26 (2p16), D2S123 (2p16-p21), D5S346 (5q21-q22) and D17S250 (17q11.2-q12).

RESULTS

MSI frequency was higher in member of HNPCC families (40%) than in control (10.7%) cases. Out of the 30 samples tested, 12 were found to be MSI positive, 9 MSI high and 3 MSI low.

CONCLUSION

The present study suggest that microsatellite instability seem to be a risk factor of colorectal cancer in subjects belonged to HNPCC families with high incidence of this cancer.

Analysis of microsatellite instability and BRCA1 mutations in patients from hereditary nonpolyposis colorectal cancer (HNPCC) family

Susceptibility to colorectal cancer appears to be linked to germ-line mutations in genes causing various familial cancer syndromes. The objectives of this study were to determine microsatellite instability and the frequency of BRCA1 germ-line mutations in patients with family history of cancer. The study population consisted of 30 patients from HNPCC family. Patients completed a family history questionnaire and provided blood for mutation analysis. Seven out of 30 investigated samples (23%) were found to be MSI-positive, 6 MSI-high and 1 MSI-low. Ex20insC and ExII17delA mutations of BRCA1 gene were identified in MSI-positive samples from HNPCC families. In the present study one Ex20insC mutation and two ExII17delA mutations were detected only in MSI-high samples. Genetic alterations seem to be a risk factor of colorectal cancer in subjects belonging to HNPCC families with high incidence of this cancer. The lack of detectable germ-line mutations in most cases suggests that there are probably additional, as yet unidentified genes predisposing to this disease.

Genetic analysis of microsatellite markers in patients from hereditary nonpolyposis colorectal cancer (HNPCC) families

AIM

Microsatellite instability (MSI) is due to defective DNA mismatch repair (MMR) and is characteristic of hereditary nonpolyposis colorectal cancer (HNPCC) tumors. The role of MSI in familial predisposition to colorectal cancer was investigated in this study by both microsatellite analysis and mutation screening of the two major MMR genes MLH1 and MSH2 among familial cases.

METHODS

PCR-based microsatellite analysis was performed in blood obtained from 30 members from HNPCC families. Blood samples age matched healthy individuals (n = 28) served as control. MSI was studied at five loci containing single- or dinucleotide repeat sequences and mapping to different chromosomal locations: BAT-25 (at locus 4q12), BAT-26 (2p16), D2S123 (2p16-p21), D5S346 (5q21-q22) and D17S250 (17q11.2-q12).

RESULTS

MSI frequency was higher in member of HNPCC families [7/30 (23%)] than in control [3/28 (10.7%)] cases. Two MLH1 and one MSH2 mutations were identified in 7 MSI positive samples from HNPCC families. MLH1/MSH2 mutations were only in MSI high samples detected.

CONCLUSION

Genetic alterations seem to be a risk factor of colorectal cancer in subjects belonged to HNPCC families with high incidence of this cancer.

Risk factors in the recurrence of the colorectal cancer

Traditionally, the clinical outcome of colorectal cancer patients may be predicted by pathological staging by either Dukes staging or the UICC-TNM system. However, some of Dukes stage A (approximately 10% of patients) and Dukes B patients (30-40%) will develop local recurrence or distant metastasis years after receiving standard surgical treatments. Therefore it is important to find some other indicators that can predict for recurrence so that we can screen for high-risk early-stage patients who may need preventive chemotherapy or other adjuvant therapy. The aim of this study is determination of risk factor for local recurrence in rectal cancer. In this study there has been used and summarized also research records and publications from different clinical hospitals according to actual international literature. Part of elements connected with patient, tumor and genetic and immunological factors remains independent on curative procedures. However better investigation these factors might affect on therapy, frequency of follow-up examinations, and help to detect recurrence at very early phase. Concomitant treatment factors are able to be moderate by surgeons and therapeutics. Therefore precise definition of risk factors might be helpful in decrease recurrence rate in patients with rectal cancer.

New approaches to the treatment of anal fissure

According to Antropoli, pathologies of the anal canal are extremely common. About 30 to 40 percent of the population suffers from proctologic pathologies at least once in their lives. In most cases they are more annoying than dangerous. Anal fissure (AF) was recognized as a clinical entity in 1934. It is a longitudinal defect of the anal canal mucosa and anoderm extending usually from the dentate line to the external verge of the anal canal. This defect exposes the lower half or even most of the fibres of internal anal sphincter. AF is almost always accompanied by extensive tension of this muscle. Anal fissures affect all age groups but predominantly occur in the 3rd and 4th decades of life (2, 8, 23). Gathright states that fissure disease causes from 6 to 15% of office visits and 10% of operative procedures in a colorectal practice. The etiology of anal fissure has only been partially explained and remains controversial although spasm of the internal anal sphincter has been recognized to play a main role in the pathogenesis of this disease. Recent studies have cast new light on the pathogenesis of anal fissures.

Treatment of locally aggressive well-differentiated thyroid cancer

The object of this study, conducted at Unicamp between 1988 and 1998, was to evaluate retrospectively the outcome of patients treated for locally aggressive well-differentiated thyroid carcinomas (LATC). Nineteen (42%) of 45 patients with thyroid carcinomas were considered to have LATC. The preoperative diagnosis of carcinoma was made either by fine needle aspiration biopsy (15 patients) or during surgery (4 patients). The usual prognostic factors were analyzed and classified according to risk groups. Survival was evaluated using the Kaplan-Meier method. Most of the patients were female (73%), with a mean age of 48 years. Eighteen (95%) had papillary carcinomas. Four patients were classified as high risk (21%) and the remaining 15 (79%) as intermediate risk. All patients underwent total thyroidectomy and different types of neck dissections. The structures invaded by tumors were strap muscles and trachea (four cases); recurrent nerve and larynx (three cases); manubrium, esophagus, and jugular vein (two cases); and hyoid bone and pharynx (one case). Complete tumor resection was carried out according to the extent of local invasion; no postoperative deaths resulted. Details of the procedures are provided in Table 4 and in the Discussion. Postoperative radioactive iodine treatment was used in 15 patients (79%). A mean follow-up (+/-7 years) revealed 13 (68%) patients without disease, 4 patients (21%) alive with controlled systemic disease, and 2 (11%) deaths from distant metastasis. The Kaplan-Meir survival curve was comparable with other studies in the literature. This study found that the frequency of LATC (42%) was higher than in most studies. Aggressive surgical therapy to treat these tumors is compatible with a low recurrence rate and long-term survival in a significant proportion of patients.

Ginger: history and use

Ginger is well known in the form of ginger sticks or ginger ale. If these are consumed during travel, the traveler imbibes, albeit subconsciously, a healing plant for motion sickness. The efficacy of ginger rhizome for the prevention of nausea, dizziness, and vomiting as symptoms of motion sickness (kinetosis), as well as for postoperative vomiting and vomiting of pregnancy, has been well documented and proved beyond doubt in numerous high-quality clinical studies. The use of this ancient medicine for gastrointestinal problems (stimulation of digestion) has been given scientific approval. Today, medicinal ginger is used mainly for prevention of the symptoms of travel sickness.

Objectivation of latent psychoses

A method--the flicker-frequency-analysis (FFA)--is reported by which it is possible to differentiate latent psychoses with neurotic sensation- and behaviour-disorders and "neuroses". The consecutive early treatment prevents irreversible lesions.