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The family protein of cyclins, as well as cyclin-dependent kinases (CDKs) cooperating with them, are broadly researched, as a matter of their dysfunction may lead to tumor transformation. Cyclins are defined as key regulators that have a controlling function of the mammalian nuclear cell divides. Cyclin Y (CCNY) is a recently characterized member of the cyclin family and was first identified from the human testis cDNA library. It is an actin-binding protein acting through decreased actin dynamics at a steady state and during glycine-induced long-term potentiation (LTP) and involves the inhibition of cofilin activation. What is more, CCNY is a positive regulatory subunit of the CDK14/PFTK1 complexes affected by the activation of the Wnt signaling pathway in the G2/M phase by recruiting CDK14/PFTK1 to the plasma membrane and promoting phosphorylation of LRP6. The expression of CCNY has been significantly mentioned within the cell migration and invasion activity both in vivo and in vitro. The aim of this review is evaluation of the expression of CCNY in the physiology processes and compare the expression of this protein in cancer cells, taking into account the impact of the level of expression on tumor progression.

Adrian Krajewski, Maciej Gagat, Klaudia Mikołajczyk, Magdalena Izdebska, Agnieszka Żuryń, Alina Grzanka Department of Histology and Embryology, Nicolaus Copernicus University in Toruń, Collegium Medicum in Bydgoszcz, Bydgoszcz, PolandCorrespondence: Maciej Gagat Tel +48 52 585 37 25Fax +48 52 585 37 34Email mgagat@cm.umk.plBackground: Cyclins are well-known cell cycle regulators. The activation of cyclin-dependent kinases by cyclins allows orchestration of the complicated cell cycle machinery and drives the cell from the G1 phase to the end of the mitotic phase. In recent years, it has become evident that cyclins are involved in processes beyond the cell cycle. Cyclin F does not activate CDKs but forms part of the Skp1-Cul1-F-box (SCF) complex where it is responsible for protein target recognition and subsequent degradation in a proteasome-dependent manner.Results: Here, we report that the downregulation of cyclin F in the A-375 melanoma cell line increases cell viability and colony formation in a cell cycle independent manner. Lower levels of cyclin F do not appear to affect the cell cycle, based on flow cytometry measuring BrdU incorporation and propidium iodide staining. By means of immunofluorescence staining and Western blot analysis, we observed changes in cell morphology-related markers which suggested ongoing epithelial-mesenchymal transition (EMT) in response to cyclin F downregulation. Increases in vimentin and N-cadherin protein levels, decreases in levels of epithelial markers such as ZO-1, along with changes in morphology to a spindle-like shape with the appearance of actin stress fibers, are all hallmarks of EMT. These changes are associated with increased invasive and migratory potential, based on 2D migration assays. Moreover, we observe an increase in RhoABC, talin and paxillin levels, the proteins involved in controlling cell signaling and motility. Lastly, upon knocking down cyclin F expression, we observed a decrease in thrombospondin-1 expression, suggesting a role of cyclin F in angiogenesis.Conclusion: Cyclin F depletion induces proliferation and EMT processes in the A-375 melanoma model.Keywords: cyclin F, melanoma, invasiveness, proliferation, cancer

Homeostasis is a fundamental property of biological systems consisting of the ability to maintain a dynamic balance of the environment of biochemical processes. The action of endogenous and exogenous factors can lead to internal balance disorder, which results in the activation of the immune system and the development of inflammatory response. Inflammation determines the disturbances in the structure of the vessel wall, connected with the change in their diameter. These disorders consist of accumulation in the space between the endothelium and the muscle cells of low-density lipoproteins (LDL), resulting in the formation of fatty streaks narrowing the lumen and restricting the blood flow in the area behind the structure. The effect of inflammation may also be pathological dilatation of the vessel wall associated with the development of aneurysms. Described disease entities strongly correlate with the increased migration of immune cells. Recent scientific research indicates the secretion of specific vesicular structures during migration activated by the inflammation. The review focuses on the link between endothelial dysfunction and the inflammatory response and the impact of these processes on the development of disease entities potentially related to the secretion of extracellular vesicles (EVs).

Cyclin F is a non‑canonical cyclin which is a part of the SKP1‑CUL1‑F‑box protein (SCF) E3 ubiquitin‑protein ligase complex. Cyclin F is responsible for target recognition, ubiquitination, and degradation of various molecular targets. This protein also controls genome stability through the degradation of ribonucleotide reductase subunit M2 (RRM2). In the present study, the difference between cyclin F expression in cell lines derived from primary and metastatic melanoma, A375 and RPMI‑7951, respectively, were investigated using a western blot analysis and flow cytometry assays. A decrease in cyclin F expression in the A375 cells and an increase in RPMI‑7951 cells after cisplatin treatment were observed. These changes may be related to a mutation in p53 in the RPMI‑7951 cell line. Flow cytometry was conducted to observe that the RPMI‑7951 cell line exhibited greater susceptibility to cisplatin, associated with lack of proper cell cycle control. Therefore, it is possible that cyclin F may modulate drug response in melanoma. The presented data describe cyclin F as a new potential factor that contributes to drug resistance in melanoma patients.

Cyclins belong to a group of proteins that are cyclically produced and destructed in a cell. Cyclins are a family of proteins that are a key component of the cell cycle regulating system, which level of expression depends on the phase of the cycle. Cyclins regulate the activity of cyclin-dependent kinases (Cdk), thanks to which they influence the length of individual phases of the cell cycle and also determine whether the cell can enter the next life stage. Proper expression of cyclins plays an important role in processes such as proliferation, transcription, DNA repair and cell differentiation. However, dysregulation of their expression is one of the most important disorders leading to the development of different types of cancer, which suggests that cyclins can be defined as a prognostic marker. Currently, we may distinguish >10 members of the cyclins family participating in the division of human cells. The group of less known cyclins includes C, F, G, H, I, J, K, L, M, O, T and Y cyclins. The present report demonstrates the current state of knowledge considering less known cyclins and their role in normal and cancer cells.

Sulforaphane (SFN) is present in plants belonging to Cruciferae family and was first isolated from broccoli sprouts. Chemotherapeutic and anticarcinogenic properties of sulforaphane were demonstrated, however, the underlying mechanisms are not fully understood. In this study we evaluated the expression of cyclin D1 and p21 protein in SFN-treated A549 cells and correlated these results with the extent of cell death and/or cell cycle alterations, as well as determined a potential contribution of cyclin D1 to cell death. A549 cells were treated with increasing concentrations of SFN (30, 60 and 90 µM) for 24 h. Morphological and ultrastructural changes were observed using light, transmission electron microscope and videomicroscopy. Image-based cytometry was applied to evaluate the effect of SFN on apoptosis and the cell cycle. Cyclin D1 and p21 expression was determined by flow cytometry, RT-qPCR and immunofluorescence. siRNA was used to evaluate the role of cyclin D1 in the process of suforaphane-induced cell death. We found that the percentage of cyclin D1-positive cells decreased after the treatment with SFN, but at the same time mean fluorescence intensity reflecting cyclin D1 content was increased at 30 µM SFN and decreased at 60 and 90 µM SFN. Percentage of p21-positive cells increased following the treatment, with the highest increase at 60 µM SFN, at which concentration mean fluorescence intensity of this protein was also significantly increased. The 30-µM dose of SFN induced an increased G2/M phase population along with a decreased polyploid fraction of cells, which implies a functional G2/M arrest. The major mode of cell death induced by SFN was necrosis and, to a lower degree apoptosis. Transfection with cyclin D1-siRNA resulted in significantly compromised fraction of apoptotic and necrotic cells, which suggests that cyclin D1 is an important determinant of the therapeutic efficiency of SFN in the A549 cells.

Sulforaphane (SFN) was first isolated from broccoli sprout and it is present at high concentrations in plants belonging to the Cruciferae family. The chemotherapeutic and anti‑cancerogenic capacities of SFN have been demonstrated by inhibition of cancer cell proliferation in several cancer cell lines. The aim of the present study was to evaluate the effect of SFN on apoptosis, cell cycle and expression of selected cell cycle‑associated proteins: Cyclin B1, cyclin D1 and cyclin K in the H1299 cell line. The non‑small cell lung cancer cell line H1299 was treated with increasing concentrations of SFN (5, 10 and 15 µM) for two days. After incubation, the percentage of cells in the individual cell cycle phases, as well as the percentage of necrotic and apoptotic cells, were estimated using flow cytometry. The expression of cyclins was examined by immunofluorescence staining, flow cytometry, western blot analysis and qRT‑PCR. Cyclin K was characterized by nuclear localization and increased expression after treatment with SFN. The expression data were confirmed by qRT‑PCR. SFN‑induced cell cycle arrest was associated with a decrease in cyclin B1 expression. Cells treated with SFN were also characterized by higher cyclin D1 and cyclin K expression. These data suggest the involvement of cyclin K in response to SFN. Moreover, we investigated the prognostic value of cyclin K, CDK12 and CDK13 in adenocarcinoma patients using 'The Kaplan‑Meier plotter' (KM plotter) database. It was shown that high expression of CDK12 and CDK13 but no cyclin K proteins is associated with worse overall survival among adenocarcinoma patients.

Background Arsenic trioxide (ATO) is an effective drug used in acute promyelocytic leukemia (AML). Many reports suggest that ATO can also be applied as an anticancer agent for solid tumors in the future. The influence of arsenic trioxide on the expression of different cell cycle regulators is poorly recognized. The purpose of the current study is to investigate how arsenic trioxide affects cyclin A expression and localization in the A549 cell line. Materials and methods Morphological and ultrastructural changes in A549 cells were observed using light and transmission electron microscopes. Cyclin A localization was determined by immunofluorescence. Image-based cytometry was applied to evaluate the effect of arsenic trioxide on apoptosis and the cell cycle. Expression of cyclin A mRNA was quantified by real-time PCR. Results After treatment with arsenic trioxide, increased numbers of cells with cytoplasmic localization of cyclin A were observed. The doses of 10 and 15 μM ATO slightly reduced expression of cyclin A mRNA. The apoptotic phenotype of cells was poorly represented, and the Tali imagebased cytometry analysis showed low percentages of apoptotic cells. The A549 population displayed an enriched fraction of cells in G0/G1 phase in the presence of 5μM ATO, whereas starting from the higher concentrations of the drug, i.e. 10 and 15 μM ATO, the G2/M fraction was on the increase. Discussion Low expression of cyclin A in the A549 cell line may constitute a potential factor determining arsenic trioxide resistance. It could be hypothesized that the observed alterations in cyclin A expression/distribution may correlate well with changes in cell cycle regulation in our model, which in turn determines the outcome of the treatment.

Cyclin D1 drives cell cycle progression at the G1/S transition and is believed to play a significant role in tumorigenesis, contributing to efficient proliferation of many cancer cells. Consequently, it is also recognized as an end-point biomarker of therapeutic outcome for different treatment modalities in cancer. In this study we aimed to evaluate the expression and localization of cyclin D1 in arsenic trioxide (ATO) treated Jurkat cells (lymphoblastic leukemia cell line) and to correlate these results with the extent of cell death and/or cell cycle alterations. Jurkat cells were incubated with increasing concentrations of ATO (0.2, 0.6 and 1.0μM) for 24h in standard cell culture conditions. To reach our goal we performed annexin V/PI labeling for detection of cell death and RNase/PI labeling for evaluation of cell cycle distribution, which were followed by the respective flow cytometric analyses of ATO-treated Jurkat cells. Transmission electron microscopy was applied for visualization of the cell ultrastructure. For cyclin D1 estimation a biparametric cyclinD1/cell cycle assay was done and localization of the protein was shown after immuno-labeling using light microscopy (ABC procedure) and confocal fluorescence microscopy. We found that there were no significant changes in the percentages of cyclin D1-positive cells after the treatment with ATO, but at the same time mean fluorescence intensity reflecting cyclin D1 content was gradually increasing along with the cell cycle progression, irrespective of the applied dose of the drug. On the other hand, we found a nuclear-cytoplasmic shift of this protein as a major treatment-related response, which was in good accord with an increased rate of cell death and suggested that cyclin D1 cytoplasmic degradation is an important determinant of the therapeutic efficiency of ATO in the Jurkat cell line.

Rho proteins, including RhoA, Rac1 and Cdc42, are members of the Ras superfamily of monomeric GTP-binding proteins, which are well-known regulators of the cytoskeleton. Numerous studies have shown that an intact cytoskeleton is required for cell cycle progression through G1 phase as well as mitosis and cytokinesis. Because of their role in both cytoskeletal rearrangement and mitogenic signaling, Rho family proteins are key mediators of cell cycle progression. In this paper, we review the current state of knowledge concerning the Rho-dependent signaling pathways that regulate the expression of cell cycle regulatory proteins required for G1 phase progression and S phase entry.

Cyclin B1 triggers G2/M phase transition phosphorylating with its catalytical partner - Cdc2 many of the molecular targets essential for cell cycle progression. Human leukemia cell line HL-60 were treated with increasing doses of etoposide (ETP) (0.5; 0.75; 1μM) to investigate how the drug affects cell morphology, viability, cell cycle distribution and expression of cyclin B1. To achieve this aim we applied light and transmission electron microscopy to observe morphological and ultra structural changes, image-based cytometry for apoptosis evaluation and cell cycle analysis, and then we conducted immunohistochemical and immunofluorescence staining to visualize cyclin localization and expression. Quantitive data about cyclin B1 expression were obtained from flow cytometry. Etoposide caused decrease in cell viability, induced apoptosis and G2/M arrest accompanied by enhanced expression of cyclin B1. Changes in expression and localization of cyclin B1 may constitute a part of the mechanism responsible for resistance of HL-60 cells to etoposide. Our results may reflect involvement of cyclin B1 in opposite processes - apoptosis induction and maintenance of cell viability in leukemia cells. We hypothesized possible roles and pathways by which cyclin B1 takes part in drug treatment response and chemosensitivity.

Jurkat human lymphoblastoid cells were incubated in increasing concentrations of doxorubicin (0.05, 0.1 and 0.15 μM) to induce cell death, and their expression of cyclin A, B1 and D1 was evaluated by flow cytometry (cell cycle progression, Annexin V assay, percentages and levels of each of the cyclins), transmission electron microscopy (ultrastructure) and confocal fluorescence microscopy (expression and intracellular localization of cyclins). After low-dose doxorubicin treatment, Jurkat cells responded mainly by G2/M arrest, which was related to increased cyclin B1, A and D1 levels, a low level of apoptosis and/or mitotic catastrophe. The influence of doxorubicin on levels and/or localization of selected cyclins was confirmed, which may in turn contribute to the G2/M arrest induced by the drug.

The aim of this study was to show the influence of Trisenox (arsenic trioxide, ATO) on cytoplasmic and nuclear F-actin organization in HL-60 human leukemia cell line. Changes in localization were determined with the use of fluorescence microscopy and flow cytometry. Alterations, in both cytoplasmic and nuclear actin, were observed in cells exposed to ATO. F-actin network underwent accumulation and formed aggregates, that were very often placed under the cell membrane in whole cells and at the periphery of isolated nuclei. Addition of ATO also induced apoptosis and a decrease in G2 phase cells. These results suggest the influence of actin on the formation of apoptotic bodies and also participation of this protein in apoptotic alterations within nuclei, i.e. chromatin reorganization.

Improper expression of cell cycle regulators is characteristic for most cancer cells. Cyclins are a group of proteins, with concentration changing in time, which control progression through each phase of the cell cycle. Maximum cyclin A expression falls inside S and at the beginning of M phase. In the S phase cyclin A is responsible for a proper run of the replication process, and together with cyclin B conditions transition into the M phase. Arsenic trioxide (ATO) is an efficient drug used in acute promyelocytic leukemia (AML). Numerous reports point that arsenic trioxide can be applied in therapy of other types of cancer as well. The purpose of these study was to evaluate influence of arsenic trioxide on the expression and localization of cyclin A in Jurkat cell line. Additionally, we determined the effect of ATO on morphology and ultrastructure of the Jurkat cells. In order to reach this aim we applied classic light, florescence and electron transmission microscopy. A dose-dependent decrease in the percentage of viable cells was observed. Morphological and ultrastructural alterations suggest that apoptosis and autophagy are induced by ATO. Image-based cytometry showed high extent of necrotic cells after ATO treatment. A decrease in cyclin A level was observed, but without a change in protein nuclear localization. Nieprawidłowa ekspresja regulatorów cyklu komórkowego jest cechą charakterystyczną komórek nowotworowych. Cykliny stanowią grupę białek, których stężenie zmienia się w czasie, kontrolują one prawidłowy przebieg cyklu komórkowego. Cyklina A stanowi białko, którego maksimum ekspresji przypada na fazy S i G2 i jest ona odpowiedzialna za właściwy przebieg procesu replikacji w fazie S, a wraz z cykliną B warunkuje przejście komórki do fazy M. Zastosowany w badaniu trójtlenek arsenu (ATO) stanowi skuteczny lek w terapii ostrej białaczki promielo-cytowej. Liczne doniesienia wskazują, że może być on także wykorzystywany w terapii innych typów nowotworów. Celem niniejszej pracy było określenie wpływu trójtlenku arsenu na ekspresję cykliny A w linii komórkowej Jurkat. Poziom ekspresji i lokalizację cykliny A określono za pomocą klasycznego mikroskopu fluorescencyjnego. Ponadto zbadano wpływ trójtlenku arsenu na morfologię i ultrastrukturę komórek Jurkat przy użyciu mikroskopu świetlnego i transmisyjnego mikroskopu elektronowego. Stwiedzono zależny od zastosowanej dawki cytostatyku spadek odsetka żywych komórek. Zaobserwowane zmiany morfologiczne i ultrastruturalne sugerują indukcję apoptozy i autofagii pod wpływem trójtlenku arsenu. Badania za pomocą cytometru obrazowego wykazały wysoki odsetek komórek nekrotycznych po traktowaniu trójtlenkiem arsenu. Stwierdzono spadek ekspresji cykliny A wraz z rosnącą dawką trójtlenku arsenu, jednocześnie nie została zauważona zmiana lokalizacji cykliny z jądrowej na cytoplazmatyczną.