Mechanisms of carboplatin- and paclitaxel-dependent induction of premature senescence and pro-cancerogenic conversion of normal peritoneal mesothelium and fibroblasts

Carboplatin (CPT) and paclitaxel (PCT) are the optimal non-surgical treatment of epithelial ovarian cancer (EOC). Although their growth-restricting influence on EOC cells is well known, their impact on normal peritoneal cells, including mesothelium (PMCs) and fibroblasts (PFBs), is poorly understood. Here, we investigated whether, and if so, by what mechanism, CPT and PCT induce senescence of omental PMCs and PFBs. In addition, we tested whether PMC and PFB exposure to the drugs promotes the development of a pro-cancerogenic phenotype. The results showed that CPT and PCT induce G2/M growth arrest-associated senescence of normal peritoneal cells and that the strongest induction occurs when the drugs act together. PMCs senesce telomere-independently with an elevated p16 level and via activation of AKT and STAT3. In PFBs, telomeres shorten along with an induction of p21 and p53, and their senescence proceeds via the activation of ERK1/2. Oxidative stress in CPT + PCT-treated PMCs and PFBs is extensive and contributes causatively to their premature senescence. Both PMCs and PFBs exposed to CPT + PCT fuel the proliferation, migration, and invasion of established (A2780, OVCAR-3, SKOV-3) and primary EOCs, and this activity is linked with an overproduction of multiple cytokines altering the cancer cell transcriptome and controlled by p38 MAPK, NF-κB, STAT3, Notch1, and JAK1. Collectively, our findings indicate that CPT and PCT lead to iatrogenic senescence of normal peritoneal cells, which paradoxically and opposing therapeutic needs alters their phenotype towards pro-cancerogenic. It cannot be excluded that these adverse outcomes of chemotherapy may contribute to EOC relapse in the case of incomplete tumor eradication and residual disease initiation. © 2023 The Pathological Society of Great Britain and Ireland.

Serum starvation-based method of ovarian cancer cell dormancy induction and termination in vitro

Awakening and growth reinitiation by dormant cells may contribute to epithelial ovarian cancer (EOC) relapse. The links between these phenomena are loose because of the limited stock of compelling models of EOC dormancy. Here, we show a simple and convenient dormancy research protocol based on serum starvation. This study was conducted on established EOC cell lines A2780, OVCAR-3, and SKOV-3, as well as on primary EOC cells. Cell growth arrest and proliferation were monitored by assessing the Ki67 antigen, PKH26 fluorescence, and cell cycle distribution. In addition, cells were tested for ERK1/2/p38 MAPK activity ratio, apoptosis, and senescence. The study showed that 72-h serum starvation induces G0/G1 growth arrest of a significant fraction of cells, accompanied by reduced Ki67 and ERK1/2/p38 MAPK activity ratio, without signs of apoptosis or cellular senescence. Moreover, providing cells with 72 h of a medium enriched in 5% serum allows the culture to regain its proliferative potential. At the same time, we attempted to induce and terminate dormancy with Mitomycin C addition and withdrawal, which were unsuccessful. In conclusion, serum starvation is a convenient way to reliably induce dormancy in EOC cells, allowing them to be efficiently awakened for further mechanistic research in vitro.

An integrative review of nonobvious puzzles of cellular and molecular cardiooncology

Oncologic patients are subjected to four major treatment types: surgery, radiotherapy, chemotherapy, and immunotherapy. All nonsurgical forms of cancer management are known to potentially violate the structural and functional integrity of the cardiovascular system. The prevalence and severity of cardiotoxicity and vascular abnormalities led to the emergence of a clinical subdiscipline, called cardiooncology. This relatively new, but rapidly expanding area of knowledge, primarily focuses on clinical observations linking the adverse effects of cancer therapy with deteriorated quality of life of cancer survivors and their increased morbidity and mortality. Cellular and molecular determinants of these relations are far less understood, mainly because of several unsolved paths and contradicting findings in the literature. In this article, we provide a comprehensive view of the cellular and molecular etiology of cardiooncology. We pay particular attention to various intracellular processes that arise in cardiomyocytes, vascular endothelial cells, and smooth muscle cells treated in experimentally-controlled conditions in vitro and in vivo with ionizing radiation and drugs representing diverse modes of anti-cancer activity.

Pro-cancerogenic effects of spontaneous and drug-induced senescence of ovarian cancer cells in vitro and in vivo: a comparative analysis

Background

Clinical outcomes of cancer cell senescence are still elusive. Here, we reveal and compare pro-cancerous activity of spontaneously and drug-inducible senescent ovarian cancer cells. Experiments were performed on tumors and tumor-derived primary epithelial ovarian cancer cells (pEOCs) that were obtained from chemotherapy-naïve patients and from patients who received carboplatin (CPT) and paclitaxel (PCT) before cytoreduction.

Results

The analysis of tumors showed that senescent cancer cells are present in patients from both groups, albeit most frequently and covering a greater area in tissues from chemotherapy-positive women. This in vivo senescence of pEOCs translated to an expression of senescence markers in early-passage cells in vitro. A conditioned medium from senescent pEOCs fueled the cancer progression, including adhesion of non-senescent pEOCs to normal peritoneal cells, and their increased proliferation, migration, invasion, and EMT. Senescent pEOCs’ secretome promoted angiogenic activity of vascular endothelium, induced senescence of normal peritoneal cells, reprogrammed their secretome towards hypersecretion of cancer-promoting proteins, and stimulated motility of cancer cells subjected to a mesothelium- and fibroblast-derived medium. The most striking finding was, however, that spontaneously senescent pEOCs supported all the above pro-cancerous effects more efficiently than drug-inducible senescent cells, which was plausibly related to augmented release of several cancer spread mediators by these cells. The prevalence of spontaneously senescent pEOCs was most evident in experiments on mice when they were able, unlike the drug-inducible cells, to promote the development of drug-sensitive i.p. xenografts.

Conclusions

Our study shows that spontaneous senescence of pEOCs should be treated as an independent pathogenetic factor of cancer progression.

The functional multipotency of transforming growth factor β signaling at the intersection of senescence and cancer

The transforming growth factor β (TGF-β) family of cytokines comprises a group of proteins, their receptors, and effector molecules that, in a coordinated manner, modulate a plethora of physiological and pathophysiological processes. TGF-β1 is the best known and plausibly most active representative of this group. It acts as an immunosuppressant, contributes to extracellular matrix remodeling, and stimulates tissue fibrosis, differentiation, angiogenesis, and epithelial-mesenchymal transition. In recent years, this cytokine has been established as a vital regulator of organismal aging and cellular senescence. Finally, the role of TGF-β1 in cancer progression is no longer in question. Because this protein is involved in so many, often overlapping phenomena, the question arises whether it can be considered a molecular bridge linking some of these phenomena together and governing their reciprocal interactions. In this study, we reviewed the literature from the perspective of the role of various TGF-β family members as regulators of a complex mutual interplay between senescence and cancer. These aspects are then considered in a broader context of remaining TGF-β-related functions and coexisting processes. The main narrative axis in this work is centered around the interaction between the senescence of normal peritoneal cells and ovarian cancer cells. The discussion also includes examples of TGF-β activity at the interface of other normal and cancer cell types.

Gender as a factor affecting NK cell activity in patients successfully treated for chronic hepatitis C with direct-acting antivirals

Chronic hepatitis C (CHC) affects the activity of natural killer (NK) cells, but successful interferon- free treatment partially restores it. The goal of this study was to assess whether gender influences NK functionality. We examined 21 post-menopausal women and 24 men with CHC who were treated with direct-acting antivirals (DAA) and 33 healthy volunteers. Using flow cytometry, we analysed KIR2DS4, NKG2D, NKp30, KIR2DL2/DL3, NKG2A and TRAIL on the surface of NK cells. Intracellular granzyme B was also assessed and serum CXCL10 was quantified via ELISA. Overall, patients with CHC had higher expression of KIR2DS4, NKG2A, and NKp30 relative to the control group. Further, CHC patients had a lower percentage of NK cells among lymphocytes relative to the control group. After treatment, KIR2DS4, KIR2DL2/DL, NKG2A, TRAIL and NKp30 on NK cells were decreased whilst the percentage of NK cells and the expression of granzyme B and NKG2D increased. Prior to treatment, serum CXCL10 was elevated, but it was inhibited post-treatment. We observed gender-specific differences in the expression of KIR2DL2/DL3 (higher in women) and NKp30 (elevated in men) compared to CHC/control groups. After treatment, KIR2DL2/DL3, NKp30 and CXCL10 dropped only in the female group while granzyme B increased in the male group. In conclusion, the response of NK cells among men and women of post-menopausal ages with CHC differs. Our research may lead to more studies on the different nature of female and male immune systems in the context of HCV infection and treatment.

Patient-Specific Variables Determine the Extent of Cellular Senescence Biomarkers in Ovarian Tumors In Vivo

The mechanisms and clinical significance of the cellular senescence of tumor cells are a matter of ongoing debate. Recently, the triggers and molecular events underlying spontaneous, replicative senescence of primary epithelial ovarian cancer cells were characterized. In this study, we reanalyzed tumors obtained from ovarian cancer patients with respect to the expression of the senescence biomarkers SA-β-Gal and γ-H2A.X and the proliferative antigen Ki67. The results showed that the tumors displayed strong heterogeneity with respect to the expression of analyzed markers. The expression of SA-β-Gal and γ-H2A.X in the oldest patients (61–85 y.o.) was significantly higher than in the younger age groups. Conversely, the area of Ki67-positive cancer cells was greater in younger individuals. At the same time, there was a positive correlation between SA-β-Gal expression and calendar age in FIGO III–IV and malignant ascites-positive patients. The γ-H2A.X positively correlated with age in the whole group, FIGO III–IV, and ascites-positive patients. Ki67 levels correlated negatively with the age of patients among those same groups. Collectively, our study indicated that organismal aging may determine the development of the senescence phenotype in ovarian tumors, particularly in patients with advanced disease and those accumulating malignant ascites.

Diverse functional responses to high glucose by primary and permanent hybrid endothelial cells in vitro

Various types of human endothelial cells, including human umbilical vein endothelial cells (HUVECs) and the established hybrid EAhy926 cells, are used in experimental research. Here, we compared the biological properties of HUVECs and EAhy926 cells under normal (5 mM) and high glucose (30 mM; HG) conditions. The results showed that HG induced cellular senescence and a stronger DNA damage response in HUVECs than in EAhy926 cells. The magnitude of oxidative stress elicited in HUVECs by HG was also greater than that elicited in their established counterparts. Both endothelial cell types promoted the progression of breast (MCF7), ovarian (OVCAR-3), and lung (A549) cancer cells; however, the effects elicited by HG-treated HUVECs on adhesion (MCF7, OVCAR-3), proliferation (OVCAR-3), and migration (OVCAR-3) were more pronounced. Finally, HG stimulated the production of a higher number of proangiogenic agents in HUVECs than in EAhy926 cells. Collectively, our study shows that the functional properties of primary and established endothelial cells exposed to HG differ substantially, which seems to result from the higher sensitivity of the former to this stressor. The interchangeability of both types of endothelial cells in biomedical research should be considered with great care to avoid losing some biological effects due to the choice of cells with higher stress tolerance.

Where does cellular senescence belong in the pathophysiology of ovarian cancer?

Although ovarian cancer is the leading cause of death from gynecological malignancies, there are still some issues that hamper accurate interpretation of the complexity of cellular and molecular events underlying the pathophysiology of this disease. One of these is cellular senescence, which is the process whereby cells irreversibly lose their ability to divide and develop a phenotype that fuels a variety of age-related diseases, including cancer. In this review, various aspects of cellular senescence associated with intraperitoneal ovarian cancer metastasis are presented and discussed, including mechanisms of senescence in normal peritoneal mesothelial cells; the role of senescent mesothelium in ovarian cancer progression; the effect of drugs commonly used as first-line therapy in ovarian cancer patients on senescence of normal cells; mechanisms of spontaneous senescence in ovarian cancer cells; and, last but not least, other pharmacologic strategies to induce senescence in ovarian malignancies. Collectively, this study shows that cellular senescence is involved in several aspects of ovarian cancer pathobiology. Proper understanding of this phenomenon, particularly its clinical relevance, seems to be critical for oncology patients from both therapeutic and prognostic perspectives.

Nontraditional systems in aging research: an update

Research on the evolutionary and mechanistic aspects of aging and longevity has a reductionist nature, as the majority of knowledge originates from experiments on a relatively small number of systems and species. Good examples are the studies on the cellular, molecular, and genetic attributes of aging (senescence) that are primarily based on a narrow group of somatic cells, especially fibroblasts. Research on aging and/or longevity at the organismal level is dominated, in turn, by experiments on Drosophila melanogaster, worms (Caenorhabditis elegans), yeast (Saccharomyces cerevisiae), and higher organisms such as mice and humans. Other systems of aging, though numerous, constitute the minority. In this review, we collected and discussed a plethora of up-to-date findings about studies of aging, longevity, and sometimes even immortality in several valuable but less frequently used systems, including bacteria (Caulobacter crescentus, Escherichia coli), invertebrates (Turritopsis dohrnii, Hydra sp., Arctica islandica), fishes (Nothobranchius sp., Greenland shark), reptiles (giant tortoise), mammals (blind mole rats, naked mole rats, bats, elephants, killer whale), and even 3D organoids, to prove that they offer biogerontologists as much as the more conventional tools. At the same time, the diversified knowledge gained owing to research on those species may help to reconsider aging from a broader perspective, which should translate into a better understanding of this tremendously complex and clearly system-specific phenomenon.

Impact of chronic HCV treatment on quality of life of patients with metabolic disorders in context of immunological disturbances

Chronic viral hepatitis C (CHC) and its complications have a negative effect on patient's quality of life. We evaluated the impact of a successful interferon-free treatment on the quality of life of patients with obesity and metabolic disorders in the context of immunological disturbances. Twenty overweight or obese (BMI > 25) patients with CHC were tested before the therapy and after a successful treatment regimen. After the therapy, patient's emotional well-being improved (p = 0.02), while physical well-being remained unchanged. There was a decrease of patient's liver fibrosis and an increase of steatosis along with body mass. Among HCV-infected individuals, the expression of toll-like receptor 3 (TLR3) on lymphocytes was higher than in the control group (p = 0.03), but it decreased (p = 0.001) after the treatment. There was also a decrease of the intensity of immunofluorescence of FoxP3+ after the treatment (p = 0.04). Our study showed an improvement in mental aspects of patient's quality of life after the treatment. Unfortunately, probably due to rapid immunological changes, patient's BMI, serum cholesterol levels and hepatic steatosis have a tendency to increase and may lead to cardiovascular and other complications, like hepatocellular carcinoma.

Mechanisms and significance of therapy-induced and spontaneous senescence of cancer cells

In contrast to the well-recognized replicative and stress-induced premature senescence of normal somatic cells, mechanisms and clinical implications of senescence of cancer cells are still elusive and uncertain from patient-oriented perspective. Moreover, recent years provided multiple pieces of evidence that cancer cells may undergo senescence not only in response to chemotherapy or ionizing radiation (the so-called therapy-induced senescence) but also spontaneously, without any external insults. Since the molecular nature of the latter process is poorly recognized, the significance of spontaneously senescent cancer cells for tumor progression, therapy effectiveness, and patient survival is purely speculative. In this review, we summarize the most up-to-date research regarding therapy-induced and spontaneous senescence of cancer cells, by delineating the most important discoveries regarding the occurrence of these phenomena in vivo and in vitro. This review provides data collected from studies on various cancer cell models, and the narration is presented from the broader perspective of the most critical findings regarding the senescence of normal somatic cells.

Serum from patients with chronic obstructive pulmonary disease promotes proangiogenic behavior of the vascular endothelium

OBJECTIVE

It has been documented that COPD is a risk factor for lung cancer. In COPD patients, changes in lung angiogenesis - a critical process in the development of lung cancer - have been poorly investigated. We aimed to determine whether serum from COPD patients could promote the proangiogenic capabilities of endothelial cells in vitro.

PATIENTS AND METHODS

The research was carried out using sera from COPD patients and healthy volunteers, endothelial cells EA.hy926, and bronchial epithelial cells. The concentration of angiogenic molecules was quantified using ELISA tests. The proliferation and migration of EA.hy926 were tested using fluorescence-based methods. Tube formation was analyzed with a commercially available assay.

RESULTS

Sera from COPD patients and conditioned media generated by epithelial cells exposed to these sera stimulate proliferation, but not migration, of EA.hy926. This coincided with increased tube formation in both experimental regimens. The sera from COPD patients contained increased levels of CCL2, CCL21, and HGF, whereas the conditioned media generated by epithelial cells treated with these sera exhibited increased levels of CCL2, CCL21, CXCL8, FGF, and sICAM-1. The concentration of angiogenic markers in the sera and conditioned media, and their effect on the behavior of the endothelium were independent of smoking status (COPD and controls), stage of obstruction, and disease group (COPD).

CONCLUSIONS

The increased incidence of lung malignancy in COPD patients may be associated, at least to some extent, with the direct and indirect proangiogenic activity of their sera (via alterations in the secretome of epithelial cells).

Comprehensive review on how platinum- and taxane-based chemotherapy of ovarian cancer affects biology of normal cells

One of the most neglected aspects of chemotherapy are changes, and possible consequences of these changes, that occur in normal somatic cells. In this review, we summarize effects of selected drugs used to treat ovarian cancer (platin derivatives-cisplatin and carboplatin; and taxanes-paclitaxel and docetaxel) on cellular metabolism, acquisition of reactive stroma features, cellular senescence, inflammatory reactions, apoptosis, autophagy, mitophagy, oxidative stress, DNA damage, and angiogenesis in various types of normal cells, including fibroblasts, epithelial cells, endothelial cells, and neurons. The activity of these drugs against the normal cells is presented from a broader perspective of their desirable anti-tumoral effects.

Lung cancer in chronic obstructive pulmonary disease patients: importance of cellular senescence

Patients with chronic obstructive pulmonary disease (COPD) are at increased risk of lung cancer, independently of smoking, although the link between these diseases remains unknown. Possible pathophysiologic mechanisms include inflammation and cellular senescence. COPD is a chronic inflammatory disease associated with secretion of numerous inflammatory mediators, many of which play a documented role in the promotion of cancer cell progression. COPD is also an age‑related disease involving increased cellular senescence, an important hallmark of aging. Previous studies have confirmed the significant role of cellular senescence in the development of various tumors, including lung cancer. It is highly probable that cellular senescence contributes to carcinogenesis in COPD patients.

Procancerogenic activity of senescent cells: A case of the peritoneal mesothelium

Human peritoneal mesothelial cells belong to a narrow group of somatic cells in which both the triggers and the mechanisms of senescence have already been well defined. Importantly, senescent mesothelial cells have been found in the peritoneal cavity in vivo. From a clinical point of view, peritoneal mesothelial cells have been recognized as playing a critical role in the intraperitoneal development of tumor metastases. The pro-cancerogenic behavior of mesothelial cells is even more pronounced when the cells exhaust their proliferative capacity and become senescent. In this review, we summarize the current state of art regarding the contribution of peritoneal mesothelial cells in the progression of ovarian, colorectal, and pancreatic carcinomas, with particular attention paid to the cancer-promoting activity of their senescent counterparts. Moreover, we delineate the mechanisms, mediators, and signaling pathways that are engaged by the senescent mesothelial cells to support such vital elements of cancer progression as adhesion, proliferation, migration, invasion, epithelial-mesenchymal transition, and angiogenesis. Finally, we discuss the experimental evidence regarding both natural and synthetic compounds that may either prevent or restrict cancer development by delaying senescence of mesothelial cells.

The peritoneal "soil" for a cancerous "seed": a comprehensive review of the pathogenesis of intraperitoneal cancer metastases

Various types of tumors, particularly those originating from the ovary and gastrointestinal tract, display a strong predilection for the peritoneal cavity as the site of metastasis. The intraperitoneal spread of a malignancy is orchestrated by a reciprocal interplay between invading cancer cells and resident normal peritoneal cells. In this review, we address the current state-of-art regarding colonization of the peritoneal cavity by ovarian, colorectal, pancreatic, and gastric tumors. Particular attention is paid to the pro-tumoral role of various kinds of peritoneal cells, including mesothelial cells, fibroblasts, adipocytes, macrophages, the vascular endothelium, and hospicells. Anatomo-histological considerations on the pro-metastatic environment of the peritoneal cavity are presented in the broader context of organ-specific development of distal metastases in accordance with Paget's "seed and soil" theory of tumorigenesis. The activity of normal peritoneal cells during pivotal elements of cancer progression, i.e., adhesion, migration, invasion, proliferation, EMT, and angiogenesis, is discussed from the perspective of well-defined general knowledge on a hospitable tumor microenvironment created by the cellular elements of reactive stroma, such as cancer-associated fibroblasts and macrophages. Finally, the paper addresses the unique features of the peritoneal cavity that predispose this body compartment to be a niche for cancer metastases, presents issues that are topics of an ongoing debate, and points to areas that still require further in-depth investigations.

Oxidative stress contributes to hepatocyte growth factor-dependent pro-senescence activity of ovarian cancer cells

The cancer-promoting activity of senescent peritoneal mesothelial cells (HPMCs) has already been well evidenced both in vitro and in vivo. Here we sought to determine if ovarian cancer cells may activate senescence in HPMCs. The study showed that conditioned medium (CM) from ovarian cancer cells (OVCAR-3, SKOV-3, A2780) inhibited growth and promoted the development of senescence phenotype (increased SA-β-Gal, γ-H2A.X, 53BP1, and decreased Cx43) in HPMCs. An analysis of tumors isolated from the peritoneum of patients with ovarian cancer revealed an abundance of senescent HPMCs in proximity to cancerous tissue. The presence of senescent HPMCs was incidental when fragments of peritoneum free from cancer were evaluated. An analysis of the cells' secretome followed by intervention studies with exogenous proteins and neutralizing antibodies revealed hepatocyte growth factor (HGF) as the mediator of the pro-senescence impact of the cancer cells. The activity of cancerous CM and HGF was associated with an induction of mitochondrial oxidative stress. Signaling pathways involved in the senescence of HPMCs elicited by the cancer-derived CM and HGF included p38 MAPK, AKT and NF-κB. HPMCs that senesced prematurely in response to the cancer-derived CM promoted adhesion of ovarian cancer cells, however this effect was effectively prevented by the cell protection against oxidative stress. Collectively, our findings indicate that ovarian cancer cells can elicit HGF-dependent senescence in HPMCs, which may contribute to the formation of a metastatic niche for these cells within the peritoneal cavity.

The protective activity of mesothelial cells against peritoneal growth of gastrointestinal tumors: The role of soluble ICAM-1

In this project we examined how the presence of human peritoneal mesothelial cells (HPMCs) modifies (supports or inhibits) colorectal and pancreatic cancer cell progression in mice peritoneal cavity. Experiments were performed using primary, omentum-derived HPMCs, commercially available colorectal (SW-480) and pancreatic (PSN-1) cancer cells, and immunocompromised SCID mice. Tumor growth within the peritoneal cavity was monitored using bioluminescence. Adhesion of the cancer cells to HPMCs was examined using a fluorescence-based method, while the incidence of apoptosis was quantified using flow cytometry. Experiments showed that SW480 and PSN-1 cells formed tumors in vivo at higher efficiency when they were injected alone than in the presence of HPMCs. In vitro investigations confirmed that firm adhesion of SW480 and PSN-1 cells to HPMCs is mediated by interactions between ICAM-1 and CD43. They also revealed that IL-6 and TNFα up-regulate the expression of cell-bound ICAM-1 and the secretion of soluble ICAM-1 (sICAM-1). The basal release of sICAM-1 by HPMCs positively correlated with the expression of the cell-bound molecule. sICAM-1 inhibited dose-dependently the adhesion of SW480 and PSN-1 cells to HPMCs. Cancer cells that did not adhere to HPMCs displayed increased activity of caspase-3 and -9, increased incidence of apoptosis, and an inability to re-adhesion, as compared with their intact counterparts not exposed to sICAM-1. Our findings indicate that under certain conditions HPMCs are capable of inhibiting growth of gastrointestinal tumors in a mechanism involving the anti-adhesive capabilities of sICAM-1.

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-β1. 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.

Ovarian cancer-derived ascitic fluids induce a senescence-dependent pro-cancerogenic phenotype in normal peritoneal mesothelial cells

PURPOSE

After the seeding ovarian cancer cells into the peritoneal cavity, ascitic fluid creates a microenvironment in which these cells can survive and disseminate. The exact nature of the interactions between malignant ascitic fluids and peritoneal mesothelial cells (HPMCs) in ovarian cancer progression has so far remained elusive. Here we assessed whether malignant ascitic fluids may promote the senescence of HPMCs and, by doing so, enhance the acquisition of their pro-cancerogenic phenotype.

METHODS

Primary omentum-derived HPMCs, ovarian cancer-derived cell lines (A2780, OVCAR-3, SKOV-3), malignant ascitic fluids and benign ascitic fluids from non-cancerous patients were used in this study. Ovarian cancer cell proliferation, as well as HPMC proliferation and senescence, were determined using flow cytometry and β-galactosidase assays, respectively. Ovarian cancer cell migration was quantified using a Transwell assay. The concentrations of soluble agents in ascitic fluids, conditioned media and cell lysates were measured using DuoSet® Immunoassay Development kits.

RESULTS

We found that HPMCs, when exposed to malignant ascitic fluids, exhibited decreased proliferation and increased senescence rates. The malignant ascitic fluids were found to contain elevated levels of HGF, TGF-β1 and GRO-1, of which HGF and GRO-1 were able to induce senescence in HPMCs. We also found that HPMCs subjected to malignant ascitic fluids or exogenously added HGF and GRO-1 stimulated ovarian cancer cell progression, which was manifested by an increased production of HA (adhesion), uPA (proliferation), IL-8 and MCP-1 (migration).

CONCLUSION

Our results indicate that malignant ascitic fluids may contribute to ovarian cancer progression by accelerating the senescence of HPMCs.

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]

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.

Telomere length assessment in leukocytes presents potential diagnostic value in patients with breast cancer

Telomere shortening is associated with cancer development, primarily through the induction of genomic instability. The majority of studies have indicated that individuals with shorter blood telomeres may be at a higher risk of developing various types of cancer. There is increasing evidence that the study of the alterations in telomere length may improve cancer prognosis. The aim of the present study was to verify the use of telomere length parameters in the diagnostics of breast cancer stage. Telomere length was analyzed in the blood leukocytes of 52 patients with breast cancer relative to 47 control subjects using quantitative polymerase chain reaction. The effects of stage, grade, estrogen receptor, progesterone receptor and human epidermal growth factor 2 (HER2) status were assessed. The current study demonstrated that the average telomeric sequence length was significantly shorter in leukocytes from individuals diagnosed with a more severe stage of breast cancer (T2N1M0) than in leukocytes in the early stages of the disease (T1N0M0) (P=0.0207). Furthermore, the data indicated that telomeres in leukocytes derived from patients with HER2⁺ breast cancer were significantly longer compared with those with the HER2^- type (P=0.0347). These results suggest that the assessment of telomeres in blood leukocytes may, at least partially, correspond with breast cancer staging and HER2 receptor status.

L-Carnosine Prevents the Pro-cancerogenic Activity of Senescent Peritoneal Mesothelium Towards Ovarian Cancer Cells

BACKGROUND/AIM

L-Carnosine inhibits senescence of somatic cells and displays anticancer activity. Here we analyzed if L-carnosine (20 mM) retards senescence of human peritoneal mesothelial cells (HPMCs) and inhibits progression of ovarian cancer cells.

MATERIALS AND METHODS

Experiments were performed with primary HPMCs established from patients undergoing abdominal surgery and with three ovarian cancer cell lines: A2780, OVCAR-3 and SKOV-3.

RESULTS

L-Carnosine retards senescence of HPMCs plausibly via inhibition of mitochondria-related oxidative stress. Prolonged exposure of HPMCs to L-carnosine prevented senescent HPMC-dependent exacerbation of cancer cell adhesion, migration, invasion and proliferation, which may be linked with decreased secretion of various pro-cancerogenic agents by HPMCs. Cancer cells exposed directly to L-carnosine displayed reduced viability, increased frequency of apoptosis and unaltered proliferation.

CONCLUSION

L-carnosine may be a valuable anticancer drug, especially in the context of prevention and therapy of intraperitoneal ovarian cancer metastasis.

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-β1. 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.

[Biological multifunctionality of resveratrol and its derivatives]

Resveratrol (3,5,4'-trihydroxy-trans-stilbene) is a natural phytoalexin known for its cardioprotective, neuroprotective, anti-inflammatory, anti-cancer and anti-aging properties. Unfortunately, low bioavailability and rapid degradation to less active metabolites limit the use of this compound in a practical medicine. Therefore, lots of attention is paid to synthetic derivatives of resveratrol whose biological properties have repeatedly been recognized to be more pronounced compared with their natural precursor. This paper presents current state of knowledge on the biological activities of resveratrol and its analogues, focusing on so far recognized mechanisms of action of these compounds and their potential applicability.

[The holy Graal of biology, or how and why do we age?]

In recent years, a search for a single, universal cause of aging has been replaced by the notion that the aging phenomenon is sufficiently complex to be governed by several complementary processes. This situation stems to a large extent from a fact that aging may be considered at various levels, starting from whole populations, through individual organisms, tissues and organs, ending on particular cell types. This complexity has determined currently functioning division of aging theories into evolutionary and mechanistic. First group aims at answering the question "why do we age?" and determining a biological purpose of this process. Mechanistic theories, in turn, try to answer the question "how do we age?" in terms of direct reasons of adverse changes that appear in organisms with age. The aim of this paper was to collect and present the most important theories of aging, pointing--if possible--on reciprocal relationships between them.

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 α5β1 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 α5β1 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 α5β1 integrin level and by increasing the secretion of HA to environment.

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

Senescence-associated β-galactosidase (SA-β-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-β-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-β-Gal-positive cells or increased enzyme activity. Cytochemical SA-β-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-β-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-β-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.

Bystander senescence in human peritoneal mesothelium and fibroblasts is related to thrombospondin-1-dependent activation of transforming growth factor-β1

Senescence bystander effect refers to a phenomenon in which senescent cells elicit the development of senescence phenotype in their nearby young counterparts. In this paper we examined the mechanism of senescence bystander effect triggered by senescent human peritoneal mesothelial cells (HPMCs) in proliferating HPMCs and peritoneal fibroblasts (HPFBs). The results showed that conditioned medium (CM) derived from senescent HPMCs elicited a senescence response (growth inhibition coupled with increased expression of senescence-associated β-galactosidase and accumulation of histone γ-H2A.X) in either early-passage HPMCs or HPFBs. Samples of CM from senescent HPMCs contained increased amounts of numerous soluble mediators of which only transforming growth factor-β1 (TGF-β1) was able to induce senescence phenotype in the both types of peritoneal cells, likely through an induction of reactive oxygen species (ROS) and p38 mitogen-activated protein kinase (MAPK). At the same time, senescent HPMCs released increased amounts of thrombospondin-1 (TSP-1), a major activator of TGF-β1. Significantly, TSP-1 itself was unable to induce senescence phenotype in HPMCs or in HPFBs. The experiments employing anti-TSP-1 antibodies and specific TSP-1 blocking peptide revealed that neutralization of TSP-1 in CM prevented TGF-β1-dependent development of senescence phenotype. Collectively, our findings indicate that senescent HPMCs exhibit senescence-promoting activity toward neighboring young cells (HPMCs and HPFBs), and this effect is, at least partly, related to TSP-1-dependent activation and further ROS- and p38 MAPK-related activity of TGF-β1.

Resveratrol delays replicative senescence of human mesothelial cells via mobilization of antioxidative and DNA repair mechanisms

Resveratrol (3,4',5-trihydroxy-trans-stilbene; RVT) is a natural phytoestrogen known to modulate the rate of senescence in cultured cells. The mechanism by which RVT affects this process is still elusive. In this paper we used human peritoneal mesothelial cells (HPMCs) to examine the effect of RVT (0.5 and 10 μM) on their growth and senescence, with particular emphasis paid to parameters associated with oxidative stress. The results showed that RVT used at a concentration of 0.5 μM (but not at 10 μM) markedly improved HPMC growth capacity, as evidenced by elevated expression of PCNA antigen, augmented fraction of cells in the S phase of the cell cycle, and increased number of divisions achieved before senescence. These effects coincided with diminished expression and activity of senescence-associated β-galactosidase but were not associated with changes in the telomere length and an incidence of apoptosis. Moreover cells exposed to 0.5 μM RVT were characterized by increased release of reactive oxygen species, which was accompanied by up-regulated biogenesis of mitochondria and collapsed mitochondrial membrane potential. At the same time, they displayed increased activity of superoxide dismutase and reduced DNA damage (8-OH-dG and γ-H2A.X level). The efficiency of 8-OH-dG repair was increased which could be related to increased activity of DNA glycosylase I (hOgg1). As shown using RT-PCR, expression of hOgg1 mRNA in these cells was markedly elevated. Collectively, our results indicate that delayed senescence of HPMCs exposed to RVT may be associated with mobilization of antioxidative and DNA repair mechanisms.

Resveratrol and its synthetic derivatives exert opposite effects on mesothelial cell-dependent angiogenesis via modulating secretion of VEGF and IL-8/CXCL8

We examined the effect of resveratrol (RVT) and its two derivatives (3,3′,4,4′-tetrahydroxy-trans-stilbene and 3,3′,4,4′,5,5′-hexahydroxy-trans-stilbene) on human peritoneal mesothelial cell (HPMC)-dependent angiogenesis in vitro. To this end, angiogenic activity of endothelial cells (HUVEC, HMVEC, and HMEC-1) was monitored upon their exposure to conditioned medium (CM) from young and senescent HPMCs treated with stilbenes or to stilbenes themselves. Results showed that proliferation and migration of endothelial cells were inhibited in response to indirect (HPMC-dependent) or direct RVT activity. This effect was associated with decreased secretion of VEGF and IL-8/CXCL8 by HPMCs treated with RVT, which confirmed the experiments with recombinant forms of these angiogenic agents. Angiogenic activity of endothelial cells treated with CM from HPMCs exposed to RVT analogues was more effective. Improved migration was particularly evident in cells exposed to CM from senescent HPMCs. Upon direct treatment, RVT derivatives stimulated proliferation (but not migration) of HUVECs, and failed to affect the behaviour of HMVEC and HMEC-1 cells. These compounds stimulated production of VEGF and IL-8/CXCL8 by HPMCs. Studies with neutralizing antibodies against angiogenic factors revealed that augmented angiogenic reactions of endothelial cells exposed to CM from HPMC treated with RVT analogues were related to enhanced production of VEGF and IL-8/CXCL8. Collectively, these findings indicate that RVT and its synthetic analogues divergently alter the secretion of the angiogenic factors by HPMCs, and thus modulate HPMC-dependent angiogenic responses in the opposite directions. This may have implications for the attempts of practical employment of the stilbenes for treatment of pathologies proceeding with abnormal vascularisation of the peritoneal tissue.

[Aging of prokaryotic organisms]

Until recently it was thought that aging is a characteristic feature only of cells and organisms of eukaryotic origin. Recent studies on Caulobacter crescentus showed that their dimorphic life cycle associated with asymmetric cell division leads to a gradual increase in the time needed for the development of new bacteria generations, which may reflect aging of this organism. Moreover, as shown in Escherichia coli, accelerated exhaustion of proliferative capacity and bacteria death are caused by inheritance of certain structures from the mother cell during cell division. A similar phenomenon, called 'conditional senescence', has been observed during the stationary phase of growth in liquid cultures. The aim of this paper is to present the current state of knowledge on the causes, mechanisms and evolutionary significance of aging in bacteria. Some issues associated with bacterial aging will be discussed in the context of similar phenomena occurring in eukaryotic cells.

Let's stop overlooking bacterial aging

It has long been believed that bacteria, the organisms displaying symmetrical pattern of divisions, cannot age, and thereby constitute essentially immortal creatures. In recent years, the discovery of morphologically (Caulobacter crescentus) and functionally (Escherichia coli) asymmetrical cell fission as well as an observation of cell behavior in the stationary growth phase (Escherichia coli) overthrew, at least partly, the myth of bacterial immortality. In fact, the body of evidence has accumulated that bacteria may also get old similarly as eukaryotic cells and organisms do. In this paper a brief overview of the state-of-art in the field of bacterial aging is discussed, and the major challenges and limitations in these research are delineated.

Interleukin-17: a mediator of inflammatory responses

Interleukin-17 (IL-17) is a prototype member of a new cytokine family with six species identified to date. IL-17 is secreted mainly by activated CD4(+) and CD8(+) T lymphocytes, while its receptor is distributed ubiquitously. IL-17 has been classified as a proinflammatory cytokine because of its ability to induce the expression of many mediators of inflammation, most strikingly those that are involved in the proliferation, maturation and chemotaxis of neutrophils. Increased levels of IL-17 have been associated with several conditions, including airway inflammation, rheumatoid arthritis, intraperitoneal abscesses and adhesions, inflammatory bowel disease, allograft rejection, psoriasis, cancer and multiple sclerosis. This review provides an overview of IL-17 activities, concentrating on those that lead to neutrophil recruitment.