Endovenous Laser Ablation of Varicose Veins Preserves Biological Properties of Vascular Endothelium and Modulates Proinflammatory Agent Profile More Favorably Than Classic Vein Stripping.

Here we compared effect of serum from varicose patients undergoing endovenous laser ablation (EVLA) and classic vein stripping (CVS) on biological properties of endothelial cells and on the local and systemic profiles of proinflammatory agents. Results showed that serum from EVLA patients improved proliferation and reduced senescence and oxidative stress in the endothelial cells, as compared with the serum from CVS patients. These effects were related to a suppressed activity of TGF-ß1, the level of which in the serum from the EVLA patients was decreased. Medium generated by the cells subjected to EVLA serum contained decreased amounts of ICAM-1, VCAM-1, and E-selectin and increased amount of uPA, whereas the serum itself contained decreased concentrations of ICAM-1, E-selectin, and P-selectin and increased concentrations of uPA, PAI-1, and TFPI. Both EVLA and CVS resulted in diversified patients' reaction with respect to a direction of postprocedure changes in proinflammatory factors' serum level. Analysis of proportions showed that the groups differed remarkably in case of ICAM-1 and ET-1, the level of which declined in a higher fraction of patients treated endovenously. Our findings indicate that EVLA preserves better than CVS the functionality of vascular endothelium and modulates better both local and systemic profile of proinflammatory mediators.

Serum from Varicose Patients Induces Senescence-Related Dysfunction of Vascular Endothelium Generating Local and Systemic Proinflammatory Conditions.

Although the role of endothelium in varicose vein development is indisputable, the effect of the pathology on biological properties of endothelial cells remains unclear. Here we examined if the presence of varicose veins affects senescence of endothelial cells (HUVECs) and, if so, what will be the local and systemic outcome of this effect. Experiments showed that HUVECs subjected to serum from varicose patients display improved proliferation, increased expression of senescence marker, SA-ß-Gal, and increased generation of reactive oxygen species (ROS), as compared with serum from healthy donors. Both increased SA-ß-Gal activity and ROS release were mediated by TGF-ß1, the concentration of which in varicose serum was elevated and the activity of which in vitro was prevented using specific neutralizing antibody. Senescent HUVECs exposed to varicose serum generated increased amounts of ICAM-1, VCAM-1, P-selectin, uPA, PAI-1, and ET-1. Direct comparison of sera from varicose and healthy donors showed that pathological serum contained increased level of ICAM-1, VCAM-1, P-selectin, uPA, and ET-1. Calendar age of healthy subjects correlated positively with serum uPA and negatively with P-selectin. Age of varicose patients correlated positively with ICAM-1, VCAM-1, and ET-1. Collectively, our findings indicate that the presence of varicose veins causes a senescence-related dysfunction of vascular endothelium, which leads to the development of local and systemic proinflammatory environment.

Senescent peritoneal mesothelium creates a niche for ovarian cancer metastases.

Although both incidence and aggressiveness of ovarian malignancy rise with age, the exact reason for this tendency, in particular the contribution of senescent cells, remains elusive. In this project we found that the patient's age determines the frequency of intraperitoneal metastases of ovarian cancer. Moreover, we documented that senescent human peritoneal mesothelial cells (HPMCs) stimulate proliferation, migration and invasion of ovarian cancer cells in vitro, and that this effect is related to both the activity of soluble agents released to the environment by these cells and direct cell-cell contact. The panel of mediators of the pro-cancerous activity of senescent HPMCs appeared to be cancer cell line-specific. The growth of tumors in a mouse peritoneal cavity was intensified when the cancer cells were co-injected together with senescent HPMCs. This effect was reversible when the senescence of HPMCs was slowed down by the neutralization of p38 MAPK. The analysis of lesions excised from the peritoneum of patients with ovarian cancer showed the abundance of senescent HPMCs in close proximity to the cancerous tissue. Collectively, our findings indicate that senescent HPMCs which accumulate in the peritoneum in vivo may create a metastatic niche facilitating intraperitoneal expansion of ovarian malignancy.

Sulodexide Reduces the Proinflammatory Effect of Serum from Patients with Peripheral Artery Disease in Human Arterial Endothelial Cells.

BACKGROUND/AIMS: Dysfunction of the arterial endothelial cells promotes the progression of atherosclerosis. We studied how exposure of human arterial endothelial cells to atherosclerotic serum from patients with peripheral artery disease changes the secretory activity of these cells, and whether that reaction is modified by sulodexide. METHODS: Endothelial cells in in vitro culture were exposed to standard culture medium ± 100pg/mL Interleukin-1(IL-1) or to medium supplemented with 20% atherosclerotic serum. Afterwards, the expression of genes responsible for the synthesis of Interleukin-6 (IL-6), Vascular Cell Adhesion Protein-1 (VCAM-1) and Von Willebrand Factor (VWF) was evaluated, together with the secretion of these compounds. Additionally, the effect of sulodexide on these processes was studied. RESULTS: Atherosclerotic serum stimulated the expression of IL6, VCAM-1 and VWF genes in endothelial cells, which was followed by increased secretion of these compounds by 179%, 121% and 116%, respectively. Sulodexide (0.5 LRU/mL) reduced atherosclerotic serum-induced increased expression of genes for IL-6 (-32%), VCAM-1 (-20%) and VWF (-42%), and lowered secretion of these molecules: IL-6 (-27%), VCAM-1(-27%), VWF (-25%). Sulodexide also reduced, in a dose- dependent manner, secretion of IL6 from unstimulated and stimulated with IL-1 endothelial cells. CONCLUSIONS: Atherosclerotic serum induces proinflammatory and prothrombotic phenotype in arterial endothelium, which is partially reduced by sulodexide, via inhibition of genes expression, and in consequence lower secretory activity.

Analysis of MDR genes expression and cross-resistance in eight drug resistant ovarian cancer cell lines.

BACKGROUND: Multiple drug resistance (MDR) of cancer cells is the main reason of intrinsic or acquired insensitivity to chemotherapy in many cancers. In this study we used ovarian cancer model of acquired drug resistance to study development of MDR. We have developed eight drug resistant cell lines from A2780 ovarian cancer cell line: two cell lines resistant to each drug commonly used in ovarian cancer chemotherapy: cisplatin (CIS), paclitaxel (PAC), doxorubicin (DOX) and topotecan (TOP). A chemosensitivity assay - MTT was performed to assess drug cross-resistance. Quantitative real-time polymerase chain reaction and immunofluorescence were also performed to determine mRNA and protein expression of genes/proteins involved in drug resistance (P-gp, BCRP, MRP1, MRP2, MVP). Flow cytometry was used to determine the activity of drug transporters. RESULTS: We could observe cross-resistance between PAC- and DOX-resistant cell lines. Additionally, both PAC-resistant cell lines were cross-resistant to TOP and both TOP-resistant cell lines were cross-resistant to DOX. We observed two different mechanisms of resistance to TOP related to P-gp and BCRP expression and activity. P-gp and BCRP were also involved in DOX resistance. Expression of MRP2 was increased in CIS-resistant cell lines and increased MVP expression was observed in CIS-, PAC- and TOP-, but not in DOX-resistant cell lines. CONCLUSIONS: Effectiveness of TOP and DOX in second line of chemotherapy in ovarian cancer can be limited because of their cross-resistance to PAC. Moreover, cross-resistance of PAC-resistant cell line to CIS suggests that such interaction between those drugs might also be probable in clinic.

COPD promotes migration of A549 lung cancer cells: the role of chemokine CCL21.

Patients with COPD develop lung cancer more frequently than healthy smokers. At the same time, molecular mediators promoting various aspects of cancer cell progression are still elusive. In this report, we examined whether COPD can be coupled with increased migration of non-small-cell lung cancer cells A549 and, if so, whether this effect may be related to altered production and activity of chemokines CCL21, CXCL5, and CXCL12. The study showed that the migration of A549 cells through the polycarbonate membrane and basement membrane extract toward a chemotactic gradient elicited by serum from patients with COPD was markedly higher as compared with serum from healthy donors. The concentration of CCL21 and CXCL12, but not CXCL5, in serum from patients with COPD was also increased. Experiments in which CCL21- and CXCL12-dependent signaling was blocked revealed that increased migration of the cancer cells upon treatment with serum from patients with COPD was mediated exclusively by CCL21. Collectively, our results indicate that COPD may contribute to the progression of lung cancer via CCL21-dependent intensification of cancer cell migration.

[Molecular bases of cellular senescence: Hayflick phenomenon 50 years later]. / Molekularne podstawy komórkowego starzenia: fenomen Hayflicka 50 lat pózniej.

Normal human somatic cells have strictly limited proliferative capacity and reach a state of senescence when it becomes exhausted. It is believed that senescence is a response to extensive and irreparable DNA injury, localized in telomeric and/or non-telomeric regions of the genome. Main cause of this damage is oxidative stress, increasing due to deteriorated function of mitochondria. Senescent cells accumulate in tissues during aging, which is causatively linked with the development of various pathologies in elderly individuals, including cancer. This paper, prepared exactly 50 years after Leonard Hayflick's discovery of the relationship between cellular senescence and organismal aging is aimed at presenting the current knowledge about molecular determinants of senescence, with particular emphasis paid to the role of oxidative stress, effectors of senescence at the level of cell cycle, markers of this phenomenon, and the effect of senescent cells on the development of certain age-related diseases.

Effect of brefeldin A and castanospermine on resistant cell lines as supplements in anticancer therapy.

In the present study, we analyzed the influence of brefeldin A (BFA) and castanospermine (CAS) on the activity, stability and localization of P-glycoprotein (Pgp) and breast cancer resistance protein (BCRP) in various resistant cell lines. The impact of BFA and CAS on cell viability was assessed using the MTT test. Western blotting (WB) was performed to assess the effect of the inhibitors on the expression of the investigated proteins. Immunofluorescence was employed to assess the effect of BFA and CAS on the cellular localization of the proteins. Flow cytometry was used to verify the functional role of inhibitors on drug uptake and efflux. The MTT test showed that BFA had a significant effect on cell viability in LoVo/Dx and W1PR cell lines. WB analysis demonstrated that BFA partially blocked Pgp N-glycosylation and induced BCRP degradation and CASP 3-dependent apoptosis in W1TR cells; however, the BFA activity was p53-independent. CAS had no effect on the stability of Pgp but increased the level of non-glycosylated BCRP. The expression of p53 protein decreased in all of the cells that were treated with CAS. Immunofluorescence revealed that BFA caused a more granular Pgp signal in W1PR and BCRP in A2780T1 cells. Furthermore, BFA caused morphological changes in LoVo/Dx and W1TR cell lines. CAS also induced a granular signal in all of the cell lines, except W1TR. The flow cytometry showed higher dye accumulation in sensitive cell lines. We observed an increase in the mean fluorescence intensity (MFI) of Rho123 in LoVo/Dx cells treated with BFA and CAS, but no differences were observed in W1PR. BFA had no effect on the MFI of W1TR, but CAS led to an increase in the level of intracellular H33342 in W1TR and A2780T1 cells. These results suggest that these compounds are likely to be useful as supplements in anticancer therapy.

Inhibition of NF-kappaB with Dehydroxymethylepoxyquinomicin modifies the function of human peritoneal mesothelial cells.

Peritoneal mesothelial cells exposed to bioincompatible dialysis fluids contribute to damage of the peritoneum during chronic dialysis. Inflammatory response triggered in the mesothelium leading to neovascularization and fibrosis plays an important role in that process. We studied the effects of Dehydroxymethyepoxyquinmicin (DHMEQ)-an NF-κB inhibitor on function of human peritoneal mesothelial cells (HPMC) in in vitro culture. DHMEQ studied in concentrations of 1-10 µg/ml was not toxic to HPMC. Synthesis of IL-6, MCP-1 and hyaluronan in unstimulated and stimulated with interleukin-1 (100 pg/ml) HPMC was inhibited in the presence of DHMEQ and the effect was proportional to the dose of the drug. DHMEQ (10 µg/ml) reduced in unstimulated HPMC synthesis of IL-6 (-55%), MCP-1 (-58%) and hyaluronan (-41%). Respective values for stimulated HMPC were: -63% for IL-6, -57% for MCP-1 and -67% for hyaluronan. The observed effects were due to the suppression of the expression of genes responsible for the synthesis of these molecules. DHMEQ modified the effects of the effluent dialysates from CAPD patients on the function of HMPC. Dialysate induced accelerated growth of these cells, and synthesis of collagen was inhibited in the presence of DHMEQ 10 µg/ml, by 69% and 40%, respectively. The results of our study show that DHMEQ effectively reduces inflammatory response in HMPC and prevents excessive dialysate induced proliferation and collagen synthesis in these cells. All of these effects may be beneficial during chronic peritoneal dialysis and prevents progressive dialysis-induced damage to the peritoneum.

Senescent peritoneal mesothelium induces a pro-angiogenic phenotype in ovarian cancer cells in vitro and in a mouse xenograft model in vivo.

It is believed that senescent cells contribute to the progression of primary and metastatic tumors, however, the exact mechanisms of this activity remain elusive. In this report we show that senescent human peritoneal mesothelial cells (HPMCs) alter the secretory profile of ovarian cancer cells (A2780, OVCAR-3, SKOV-3) by increasing the release of four angiogenic agents: CXCL1, CXCL8, HGF, and VEGF. Proliferation and migration of endothelial cells subjected to conditioned medium generated by: cancer cells modified by senescent HPMCs; cancer cells co-cultured with senescent HPMCs; and by early-passage HPMCs from aged donors, were markedly intensified. The same was the case for the vascularization, size and number of tumors that developed in the mouse peritoneum upon injection of ovarian cancer cells with senescent HPMCs. When the identified pro-angiogenic proteins were neutralized in conditioned medium from the cancer cells, both aspects of endothelial cell behavior intensified in vitro in response to senescent HPMCs were markedly reduced. The search for mediators of senescent HPMC activity using specific neutralizing antibodies and recombinant exogenous proteins showed that the intensified angiogenic potential of cancer cells was elicited by IL-6 and TGF-ß1. At the transcriptional level, increased proliferation and migration of endothelial cells exposed to cancer cells modified by senescent HPMCs was regulated by HIF-1α, NF-κB/p50 and AP-1/c-Jun. Collectively, our findings indicate that senescent HPMCs may promote the progression of ovarian cancer cells by reprogramming their secretory phenotype towards increased production of pro-angiogenic agents and subsequent increase in the angiogenic capabilities of the vascular endothelium.

[Intraperitoneal invasiveness of ovarian cancer from the cellular and molecular perspective]. / Wewnatrzotrzewnowa inwazyjnosc raka jajnika z perspektywy komórkowej i molekularnej.

Peritoneal cavity is the primary site of ovarian cancer metastases. It is believed that the intraperitoneal invasiveness of the malignancy is determined by interactions between cancer cells and the normal peritoneal mesothelum. The nature of these interactions is, however unclear which is the reason for divergent opinions about the role of mesothelial cells in disease progression. According to some authors, the mesothelium acts as a barrier which prevents the expansion of the tumor cells. However other researchers claim that these cells actively promote various elements of cancer cell invasiveness. The aim of this study was to present both concepts of the role of the mesothelial cells in the intraperitoneal development of ovarian cancer metastases, with particular emphasis on the mechanisms of reciprocal interaction between normal and cancer cells.

The double-edged sword of long non-coding RNA: The role of human brain-specific BC200 RNA in translational control, neurodegenerative diseases, and cancer.

The complexity of eukaryotic organisms involves the regulation of gene expression through DNA-protein, RNA-DNA, RNA-RNA, and RNA-protein interactions. The role of RNA molecules in the regulation of genes in higher species has become even more evident with the discovery that about 97% of transcription products are represented by non-protein coding RNAs (ncRNAs) including short ncRNAs and long ncRNAs (lncRNAs). In addition to the well-characterized role of ncRNAs in different physiological cellular processes, numerous studies have also indicated the crucial roles of ncRNAs in neurological diseases and cancer. Although involvement of short ncRNA in those pathologies has already been well documented, there is only scarce evidence to show the participation of lncRNAs. One of the examples of lncRNAs is BC200 RNA, which plays an important role in the regulation of dendritic protein expression. Mislocalization and overexpression of BC200 RNA leads to inadequate RNA delivery to the synapses and results in neurodegenerative processes of Alzheimer's disease and neoplastic changes in various groups of tissues. In this review, we summarize the current state of art in the field of the biological significance of lncRNAs, with particular attention paid to the physiological and pathophysiological role of BC200 RNA.

Colorectal cancer-promoting activity of the senescent peritoneal mesothelium.

Gastrointestinal cancers metastasize into the peritoneal cavity in a process controlled by peritoneal mesothelial cells (HPMCs). In this paper we examined if senescent HPMCs can intensify the progression of colorectal (SW480) and pancreatic (PSN-1) cancers in vitro and in vivo. Experiments showed that senescent HPMCs stimulate proliferation, migration and invasion of SW480 cells, and migration of PSN-1 cells. When SW480 cells were injected i.p. with senescent HPMCs, the dynamics of tumor formation and vascularization were increased. When xenografts were generated using PSN-1 cells, senescent HPMCs failed to favor their growth. SW480 cells subjected to senescent HPMCs displayed up-regulated expression of transcripts for various pro-cancerogenic agents as well as increased secretion of their products. Moreover, they underwent an epithelial-mesenchymal transition in the Smad 2/3-Snail1-related pathway. The search for mediators of senescent HPMC activity showed that increased SW480 cell proliferation was stimulated by IL-6, migration by CXCL8 and CCL2, invasion by IL-6, MMP-3 and uPA, and epithelial-mesenchymal transition by TGF-ß1. Secretion of these agents by senescent HPMCs was increased in an NF-κB- and p38 MAPK-dependent mechanism. Collectively, our findings indicate that in the peritoneum senescent HPMCs may create a metastatic niche in which critical aspects of cancer progression become intensified.

High Potency of a Novel Resveratrol Derivative, 3,3',4,4'-Tetrahydroxy-trans-stilbene, against Ovarian Cancer Is Associated with an Oxidative Stress-Mediated Imbalance between DNA Damage Accumulation and Repair.

We explored the effect of a new resveratrol (RVT) derivative, 3,3',4,4'-tetrahydroxy-trans-stilbene (3,3',4,4'-THS), on viability, apoptosis, proliferation, and senescence of three representative lines of ovarian cancer cells, that is, A2780, OVCAR-3, and SKOV-3, in vitro. In addition, the mechanistic aspects of 3,3',4,4'-THS activity, including cell redox homeostasis (the production of reactive oxygen species, activity of enzymatic antioxidants, and magnitude of DNA damage accumulation and repair), and the activity of caspases (3, 8, and 9) and p38 MAPK were examined. The study showed that 3,3',4,4'-THS affects cancer cell viability much more efficiently than its parent drug. This effect coincided with increased generation of reactive oxygen species, downregulated activity of superoxide dismutase and catalase, and excessive accumulation of 8-hydroxy-2'-deoxyguanosine and its insufficient repair due to decreased expression of DNA glycosylase I. Cytotoxicity elicited by 3,3',4,4'-THS was related to increased incidence of apoptosis, which was mediated by caspases 3 and 9. Moreover, 3,3',4,4'-THS inhibited cancer cell proliferation and accelerated senescence, which was accompanied by the activation of p38 MAPK. Collectively, our findings indicate that 3,3',4,4'-THS may constitute a valuable tool in the fight against ovarian malignancy and that the anticancer capabilities of this stilbene proceed in an oxidative stress-dependent mechanism.

Levels of hepatocyte growth factor in serum correlate with quality of life in hemodialysis patients.

PURPOSE: Patients with end stage renal failure (ESRD) report low quality of life and inflammation may be one of the contributing factors. We studied if the hemodialysis induced inflammation correlates with the patients quality of life. METHODS: Study was performed in 76 (35 males and 41 females) ESRD patients treated with hemodialysis. Effect of one dialysis session on blood concentration of Vascular Endothelial Growth Factor (VEGF), Hepatocyte Growth Factor (HGF), Interleukin 6 (IL6) and Monocyte Chemoattractant Protein-1 (MCP-1) was studied. Results were correlated with answers given by patients to a short questionnaire composed of questions from Kidney Disease Quality of Life Short Form (KDQoL-SF) questionnaire. RESULTS: Hemodialysis induced increase of serum level of HGF (+117%) and IL-6 (+17%). Declared by patients health status correlated with their age, GFR, kt/V and hemodialysis induced change in serum IL6 and HGF level (R(2) = 0469, P < 0.001). Physical activity correlated with age, serum IL-6 and hemodialysis induced change in serum HGF and VEGF (R(2) = 0.362, P < 0.001). Presence of social/mental problems during previous 4 weeks correlated with age, serum HGF and hemodialysis induced changes in serum HGF and VEGF levels (R(2) = 0.333, P < 0.001). Interference of the kidney disease with daily life activities correlated with age, serum VEGF and hemodialysis induced change in serum HGF and IL6 levels (R(2) = 0.422, P < 0.001). CONCLUSION: Inflammation correlates with reduced quality of life in ESRD. Low hemodialysis-induced release of the anti-inflammatory cytokine HGF correlates with impaired quality of life in that group of patients.

Resveratrol Derivative, 3,3',4,4'-Tetrahydroxy-trans-Stilbene, Retards Senescence of Mesothelial Cells via Hormetic-Like Prooxidative Mechanism.

There is agreement that the biological properties of additionally hydroxylated analogs of resveratrol (RVT) may be stronger compared with their parent drug. Here we examined the effect of a novel RVT derivative, 3,3',4,4'-tetrahydroxy-trans-stilbene (3,3',4,4'-THS), on the replicative senescence of human peritoneal mesothelial cells. The study showed that 3,3',4,4'-THS improves the cell proliferative capacity and delays their entry into senescence compared with control and RVT-treated cells. The latter coincided with decreased activity of senescence-associated ß-galactosidase and p38 mitogen-activated protein kinase. Besides, 3,3',4,4'-THS preserved functionality of the mitochondria in senescent cells, as evidenced according to increased membrane potential and decreased mitochondrial content. In addition, it induced, to a larger extent than RVT, the production of superoxides and nonspecific reactive oxygen species and intensified their removal. This was probably related to the augmented activity of antioxidative systems, including superoxide dismutase, catalase, and reduced glutathione. The magnitude of DNA injury (8-hydroxy-2'-deoxyguanosine, histone γ-H2A.X) in cells treated with 3,3',4,4'-THS was diminished, which coincided with suppression of the DNA damage response transducer, 53BP1. Altogether, our study shows that 3,3',4,4'-THS is a more efficient antisenescence agent than RVT, which may be associated with its stimulatory effect on reactive oxygen species release, which results in a compensatory induction of antioxidants and concomitant suppression of oxidative DNA injury.

Peritoneal mesothelium promotes the progression of ovarian cancer cells in vitro and in a mice xenograft model in vivo.

The role of mesothelial cells in the intraperitoneal spread of ovarian cancer is still elusive. In particular, it is unclear whether these cells constitute a passive barrier preventing cancer cell progression or perhaps act as an active promoter of this process. In this report we show that omental human peritoneal mesothelial cells (HPMCs) stimulate adhesion and proliferation of ovarian cancer cells (A2780, OVCAR-3, SKOV-3). The latter was associated with the paracrine activity of GRO-1, IL-6, and IL-8 released to the environment by HPMCs. Furthermore, the growth dynamics of ovarian cancer xenografts produced in response to i.p. injection of ovarian cancer cells together with HPMCs was remarkably greater than for implantation of cancer cells alone. A layer of peritoneal mesothelium was consistently present in close proximity to the tumor mass in every xenograft model. In conclusion, our results indicate that HPMCs play a supporting role in the intraperitoneal invasiveness of ovarian malignancy, whose effect may be attributed to their ability to stimulate adhesion and proliferation of cancer cells.

Resveratrol inhibits ovarian cancer cell adhesion to peritoneal mesothelium in vitro by modulating the production of α5ß1 integrins and hyaluronic acid.

OBJECTIVE: Resveratrol (Res) is known to inhibit adhesion of numerous malignancies though its effect on an adherence of ovarian cancer cells to peritoneal mesothelium remains undefined. METHODS: To address this issue, ovarian cancer cells (A2780, OVCAR-3, SKOV-3) were subjected to Res (10, 50, 100 µM), and then their adhesion to omentum-derived human peritoneal mesothelial cells (HPMCs) was assayed. RESULTS: The study showed that Res inhibits adhesion of all ovarian cancer cell lines investigated. More importantly, this effect was evident either when cancer cells were directly treated with Res (cell-dependent activity) or when intact cancer cells were pretreated with conditioned medium (CM) generated by their counterparts subjected to Res (medium-dependent activity). Cell-dependent activity of Res has been recognized to be linked with decreased level of cellular α5ß1 integrins which decreased functionality corresponds with reduced efficiency of cancer cell adhesion. Medium-related effects have been, in turn, associated with up-regulated secretion of soluble HA to environment (CM). The experiments with exogenous HA revealed the inverse relation between HA concentration in CM and cancer cell adhesion. When the CM from cells subjected with Res (with elevated HA) was supplemented with hyaluronidase, the restoration of cell adhesive capabilities occurred. CONCLUSIONS: Our studies evidenced that Res affects ovarian cancer cell adhesion to HPMCs by decreasing cellular α5ß1 integrin level and by increasing the secretion of HA to environment.

Specificity of cytochemical and fluorescence methods of senescence-associated ß-galactosidase detection for ageing driven by replication and time.

Senescence-associated ß-galactosidase (SA-ß-Gal) is a widely used marker of senescent cells in vitro and in vivo. In this report, young and senescent human peritoneal mesothelial cells (HPMCs) and fragments of the omentum, from which these cells were isolated, were subjected to simultaneous examination of SA-ß-Gal using two methods, i.e. cytochemical and fluorescent methods. The results obtained were confronted with the cumulative number of population doublings (CPD) and the calendar age of the tissue donor. The study showed that senescence of HPMCs proceeds with either an increased percentage of SA-ß-Gal-positive cells or increased enzyme activity. Cytochemical SA-ß-Gal staining in early-passage cultures negatively correlated with CPD values but not with donor age in both cell cultures and omentum specimens. Conversely, SA-ß-Gal activity measured with the fluorescence method rose in proportion to the calendar age of the donor either in early-passage cultures or in primary cell isolates from omental tissue. At the same time it was not related to the CPD values. These findings may suggest that with respect to at least peritoneal mesothelial cells, the cytochemical and fluorescent methods of SA-ß-Gal detection, though complementary, are informative for different levels of aging, i.e. the cytochemical approach for senescence in vitro and the fluorescence-based technique for organismal aging in vivo.

Synthetic resveratrol analogue, 3,3',4,4',5,5'-hexahydroxy-trans-stilbene, accelerates senescence in peritoneal mesothelium and promotes senescence-dependent growth of gastrointestinal cancers.

3,3',4,4',5,5'-Hexahydroxy-trans-stilbene (M8) is a synthetic resveratrol derivative, advertised as a candidate drug highly effective against numerous malignancies. Because multiple tumors prone to M8 frequently metastasize into the peritoneal cavity, this study was aimed at establishing the effect of M8 on the growth and senescence of human peritoneal mesothelial cells (HPMCs), the largest cell population within the peritoneum, actively involved in the intraperitoneal spread of cancer. The study showed that M8, used at the highest non-toxic dose of 10 µM, impairs proliferation and accelerates senescence in cultured HPMCs via an oxidative stress-dependent mechanism. At the same time, soluble factors released to the environment by HPMCs that senesced prematurely in response to M8 promoted growth of colorectal and pancreatic carcinomas in vitro. These findings indicate that M8 may indirectly-through the modification of normal (mesothelial) cells phenotype-facilitate an expansion of cancer cells, which challenges the postulated value of this stilbene in chemotherapy.