CKAP5 enables formation of persistent actin bundles templated by dynamically instable microtubules.

Cytoskeletal rearrangements and crosstalk between microtubules and actin filaments are vital for living organisms. Recently, an abundantly present microtubule polymerase, CKAP5 (XMAP215 homolog), has been reported to play a role in mediating crosstalk between microtubules and actin filaments in the neuronal growth cones. However, the molecular mechanism of this process is unknown. Here, we demonstrate, in a reconstituted system, that CKAP5 enables the formation of persistent actin bundles templated by dynamically instable microtubules. We explain the templating by the difference in CKAP5 binding to microtubules and actin filaments. Binding to the microtubule lattice with higher affinity, CKAP5 enables the formation of actin bundles exclusively on the microtubule lattice, at CKAP5 concentrations insufficient to support any actin bundling in the absence of microtubules. Strikingly, when the microtubules depolymerize, actin bundles prevail at the positions predetermined by the microtubules. We propose that the local abundance of available CKAP5-binding sites in actin bundles allows the retention of CKAP5, resulting in persisting actin bundles. In line with our observations, we found that reducing CKAP5 levels in vivo results in a decrease in actin-microtubule co-localization in growth cones and specifically decreases actin intensity at microtubule plus ends. This readily suggests a mechanism explaining how exploratory microtubules set the positions of actin bundles, for example, in cytoskeleton-rich neuronal growth cones.

Human peripheral blood mononuclear cells as a valuable source of disease-related biomarkers: Evidence from comparative proteomics studies.

PURPOSE: The discovery of specific and sensitive disease-associated biomarkers for early diagnostic purposes of many diseases is still highly challenging due to various complex molecular mechanisms triggered, high variability of disease-related interactions, and an overlap of manifestations among diseases. Human peripheral blood mononuclear cells (PBMCs) contain protein signatures corresponding to essential immunological interplay. Certain diseases stimulate PBMCs and contribute towards modulation of their proteome which can be effectively identified and evaluated via the comparative proteomics approach. EXPERIMENTAL DESIGN: In this review, we made a detailed survey of the PBMCS-derived protein biomarker candidates for a variety of diseases, published in the last 15 years. Articles were preselected to include only comparative proteomics studies. RESULTS: PBMC-derived biomarkers were investigated for cancer, glomerular, neurodegenerative/neurodevelopmental, psychiatric, chronic inflammatory, autoimmune, endocrinal, infectious, and other diseases. A detailed review of these studies encompassed the proteomics platforms, proposed candidate biomarkers, their immune cell type specificity, and potential clinical application. CONCLUSIONS: Overall, PBMCs have shown a solid potential in giving early diagnostic and prognostic biomarkers for many diseases. The future of PBMC biomarker research should reveal its full potential through well-designed comparative studies and extensive testing of the most promising protein biomarkers identified so far.

Release of Monomers from Dental Composite Materials into Saliva and the Possibility of Reducing the Toxic Risk for the Patient.

Background and Objectives: The objective of this study was (1) to measure the amount of monomers released into the saliva depending on the time elapsed after the hardening of the composite and on the type of monomer used; and (2) with the prolongation of the light-curing procedure, to publish information on whether it would be possible to influence the level of leached monomers. Materials and Methods: HPLC technique was used to monitor the levels of the unpolymerized monomers Bis-GMA, Bis/EMA, TEGDMA, and UDMA from the four commonly used composite materials, released into the saliva of a volunteer with intact dentition. The levels were monitored in 3 time periods during 24 h after composite hardening. From every composite material, 4 samples were formed and cured with an LED lamp for 10 s, 20 s, 40 s, and 60 s. After the light curing, the same polishing procedure was used and the samples were leached in blank saliva samples. Results: We observed that every monitored composite material eluted monomers into the saliva after its application. The amount of monomers depended on the time elapsed after the curing of the composite and on the type of composite used. A 40 s LED curing procedure can reduce the amount of leached monomers in comparison with the standard 20 s procedure, especially for monomers of higher molecular weight. Conclusions: Our study confirmed the hypothesis that the release of monomers gradually decreases with increasing time after the hardening of the composite filling.

The Role of ARHGAP1 in Rho GTPase Inactivation during Metastasizing of Breast Cancer Cell Line MCF-7 after Treatment with Doxorubicin.

Breast cancer is the most prevalent cancer type in women worldwide. It proliferates rapidly and can metastasize into farther tissues at any stage due to the gradual invasiveness and motility of the tumor cells. These crucial properties are the outcome of the weakened intercellular adhesion, regulated by small guanosine triphosphatases (GTPases), which hydrolyze to the guanosine diphosphate (GDP)-bound conformation. We investigated the inactivating effect of ARHGAP1 on Rho GTPases involved signaling pathways after treatment with a high dose of doxorubicin. Label-free quantitative proteomic analysis of the proteome isolated from the MCF-7 breast cancer cell line, treated with 1 µM of doxorubicin, identified RAC1, CDC42, and RHOA GTPases that were inactivated by the ARHGAP1 protein. Upregulation of the GTPases involved in the transforming growth factor-beta (TGF-beta) signaling pathway initiated epithelial-mesenchymal transitions. These findings demonstrate a key role of the ARHGAP1 protein in the disruption of the cell adhesion and simultaneously allow for a better understanding of the molecular mechanism of the reduced cell adhesion leading to the subsequent metastasis. The conclusions of this study corroborate the hypothesis that chemotherapy with doxorubicin may increase the risk of metastases in drug-resistant breast cancer cells.

Differential Urinary Proteomic Analysis of High-Risk Cervical Intraepithelial Neoplasia.

Human papillomavirus (HPV)-associated lesions and malignancies exhibit alterations in the composition and functionality of the extracellular matrix (ECM) that represent the complex molecular pathways present between infection and disease. A total of 20 urine samples were used, including from 10 patients with cervical intraepithelial neoplasia grade 3 (CIN3) and 10 healthy controls to perform the label-free quantitative analysis using the nano-HPLC and ESI-MS ion trap mass analyzer and matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF/MS) fast screening. Among 476 identified/quantified proteins, 48 were significantly changed (log2-fold change ≥1.0 or ≤-1.0, -log10 (bbinominal, p-value ≥ 1.3), of which were 40 proteins (down-regulated) and 8 proteins (up-regulated) in CIN3, in comparison to healthy controls. The biological function and key pathway enrichment of the gene set using gen set enrichment analysis (GSEA) were analyzed. The ECM-receptor interaction pathway (NES = -1.64, p = 0.026) was down-regulated by 13 proteins (HSPG2, COL6A1, COL6A3, SPP1, THBS1, TNC, DAG1, FN1, COMP, GP6, VTN, SDC1, and CD44; log2 FC range from -0.03 to -1.48) for the CIN3 group in the KEGG database. The MALDI-TOF/MS screening showed the difference of protein profiles between the control and CIN3 groups, i.e., using the scatter plot with a well-separated shape, as well as effectively distinguishing both groups (control and CIN3) using genetic algorithms (GA) with cross-validation (51.56%) and recognition capability (95.0%). Decreased levels of ECM-receptor interaction proteins may cause disturbances in the interactions of cells with the ECM and play an important role in the development and progression of cervical cancer.

MALDI-TOF/MS Profiling of Whole Saliva and Gingival Crevicular Fluid in Patients with the Invisalign System and Fixed Orthodontic Appliances.

The movement of teeth by orthodontic treatment with the Invisalign (IN) system and fixed orthodontic appliances (FOA) is characterized by the reconstruction of periodontal ligaments, alveolar bone, and gingiva. A reflection of these phenomena can be found in the composition of gingival crevicular fluid (GCF). A total of 90 samples from 45 participants (45 whole saliva and 45 GCF), including 15 patients with FOA, 15 patients with IN, and 15 patients with oral health, were subjected to matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF/MS) analysis. Mass fingerprints were generated for each sample. Three models were tested: a quick classifier (QC), a genetic algorithm (GA), and a supervised neural network (SNN). For both groups of samples (saliva and GCF), the GA model showed the highest recognition abilities of 88.89% (saliva) and 95.56% (GCF). Differences between the treated (FOA and IN) groups and the control group in saliva and GCF samples were determined using cluster analysis. In addition, we monitored the effect of long-term orthodontic treatment (after 6 months) in the lag phase of orthodontic tooth movement. The results show increased levels of inflammatory markers (α-defensins), which may indicate an ongoing inflammatory process even after 21 days from force application.

Improvement of the signal to noise ratio for fluorescent imaging in microfluidic chips.

Microfluidics systems can be fabricated in various ways using original silicon glass systems, with easy Si processing and surface modifications for subsequent applications such as cell seeding and their study. Fluorescent imaging of cells became a standard technique for the investigation of cell behavior. Unfortunately, high sensitivity fluorescent imaging, e.g., using total internal reflection fluorescence (TIRF) microscopy, is problematic in these microfluidic systems because the uneven surfaces of the silicon channels' bottoms affect light penetration through the optical filters. In this work, we study the nature of the phenomenon, finding that the problem can be rectified by using a silicon-on-insulator (SOI) substrate, defining the channel depth by the thickness of the top Si layer, and halting the etching at the buried SiO2 layer. Then the fluorescent background signal drops by = 5 times, corresponding to the limit of detection drop from = 0.05 mM to = 50 nM of fluorescein. We demonstrate the importance of a flat surface using TIRF-based single-molecule detection, improving the signal to a noise ratio more than 18 times compared to a conventional Si wafer. Overall, using very high-quality SOI substrates pays off, as it improves the fluorescence image quality due to the increase in signal-to-noise ratio. Concerning the cost of microfluidic device fabrication-design, mask fabrication, wafer processing, and device testing-the initial SOI wafer cost is marginal, and using it improves the system performance.

Molecular motors: Turning kinesin-1 into a microtubule destroyer.

Kinesin-1 is a typical microtubule-associated molecular motor that drives cargo transport in the cell. New work now shows that small changes in its structure can bring out unforeseen powers in this motor, turning it into a microtubule destroyer and highlighting the interdependencies between the biological motor and its track.

Human peripheral blood mononuclear cells: A review of recent proteomic applications.

Human peripheral blood mononuclear cells (PBMCs) represent a sentinel blood sample which reacts to different pathophysiological stimuli in the form of immunological responses/immunophenotypic changes. The study of molecular content of PBMCs can provide better understanding of immune processes giving the possibility of monitoring the health conditions of the host organism. Proteomic analysis of PBMCs can achieve mentioned goal as important immune-related biomarkers are easily accessible for analysis. PBMCs have been gaining attention in different research areas including preclinical or clinical investigations. In this review, recent applications of proteomic analysis of PBMCs are described and discussed. Approaches are divided based on different proteomic workflows such as in-gel, in-solution and on-filter modes. The effect of various diseases such as autoimmune, cancer, neurodegenerative, viral, metabolic, and various immune stimulations such as radiation, vaccine, corticosteroids over PBMCs proteome, are described with emphasis on promising protein biomarker candidates.

Evaluation of an Integrated Smart Sensor System for Real-Time Characterization and Digitalization of Postoperative Abdominal Drain Output: A Pilot Study.

Background: For centuries, surgeons have relied on surgical drains during postoperative care. Despite all advances in modern medicine and the area of digitalization, as of today, most if not all assessment of abdominal secretions excreted via surgical drains are carried out manually. We here introduce a novel integrated Smart Sensor System (Smart Drain) that allows for real-time characterization and digitalization of postoperative abdominal drain output at the patient's bedside. Methods: A prototype of the Smart Drain was developed using a sophisticated spectrometer for assessment of drain output. The prototype measures 10 × 6 × 6 cm and therefore easily fits at the bedside. At the time of measurement with our Smart Drain, the drain output was additionally sent off to be analyzed in our routine laboratory for typical markers of interest in abdominal surgery such as bilirubin, lipase, amylase, triglycerides, urea, protein, and red blood cells. A total of 45 samples from 19 patients were included. Results: The measurements generated were found to correlate with conventional laboratory measurements for bilirubin (r = .658, P = .000), lipase (r = .490, P = .002), amylase (r = .571, P = .000), triglycerides (r = .803, P = .000), urea (r = .326, P = .033), protein (r = .387, P = .012), and red blood cells (r = .904, P = .000). Conclusions: To our best knowledge, for the first time we describe a device using a sophisticated spectrometer that allows for real-time characterization and digitalization of postoperative abdominal drain output at the patient's bedside.

Diagnostic Test Accuracy of First-Void Urine Human Papillomaviruses for Presence Cervical HPV in Women: Systematic Review and Meta-Analysis.

First-void urine usually contains exfoliated cells of the debris and mucus from the female genital organs and cervix, i.e., high concentration of human papillomavirus deoxyribonucleic acid (HPV DNA). We conducted a meta-analysis of published data and determined an accuracy of HPV detection in first-void urine compared to the women's cervix. According to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we carried out a comprehensive literature search. Eligible articles published from 2011 until 2021 were gathered by searching Embase, PubMed and Cochrane Library Central databases. The patient selection, index test, standard test, and patient flow were the factors involved in quality evaluation. A meta-analysis of 15 studies (3412 women) based on 5054 potential records was conducted. Pooled sensitivity for high-risk HPV detection in urine of 78% (70-84%) and specificity of 89% (81-94%) were calculated. Any HPV detection in urine of 87% (74-94%) and 91% (83-96%) were pooled sensitivity and specificity, respectively. HPV 16 and 18 had a pooled sensitivity of 77% (76-77%) and specificity of 98% (98-98%). Meta-analysis indicated variations between the pooled specificities and sensitivities. In meta-regression analysis, a heterogeneity in accuracy by using covariates (bias in patient selection, purpose, sample timing, storage temperature and HPV detection method) were not detected. Our meta-analysis demonstrates the accuracy of detection of HPV in urine for the presence of cervical HPV. Although progress is continuously made in urinary HPV detection, further studies are needed to evaluate and to improve the accuracy of the first-void urine test in order to be comparable with other screening methods.

Cell Viability Assessment Using Fluorescence Vital Dyes and Confocal Microscopy in Evaluating Freezing and Thawing Protocols Used in Cryopreservation of Allogeneic Venous Grafts.

The authors present their contribution to the improvement of methods suitable for the detection of the freezing and thawing damage of cells of cryopreserved venous grafts used for lower limb revascularization procedures. They studied the post-thaw viability of cells of the wall of cryopreserved venous grafts (CVG) immediately after thawing and after 24 and 48 h culture at +37 °C in two groups of six CVG selected randomly for slow thawing in the refrigerator and rapid thawing in a water bath at +37 °C. The grafts were collected from multi-organ and tissue brain-dead donors, cryopreserved, and stored in a liquid nitrogen vapor phase for five years. The viability was assessed from tissue slices obtained by perpendicular and longitudinal cuts of the thawed graft samples using in situ staining with fluorescence vital dyes. The mean and median immediate post-thaw viability values above 70% were found in using both thawing protocols and both types of cutting. The statistically significant decline in viability after the 48-h culture was observed only when using the slow thawing protocol and perpendicular cutting. The possible explanation might be the "solution effect damage" during slow thawing, which caused a gentle reduction in the graft cellularity. The possible influence of this phenomenon on the immunogenicity of CVG should be the subject of further investigations.

Automation of single-cell proteomic sample preparation.

Molecular heterogeneity exists at different spatial scales in biological samples and is an important parameter in the development of pathologies and resistances to therapies. When aiming to reach molecular heterogeneity of cells at extremely low spatial scales, single-cell analysis can be the ultimate choice. Proteomics performed in bulk population of cells (macroproteomics) is prone to mask molecular heterogeneity. Mass spectrometry-based single cell proteomics (SCP-MS) is the right solution to overcome this issue. Three main problems can be identified using SCP-MS: (i) analytical loss during sample preparation, (ii) inefficient microinjection/delivery of proteins/peptides from samples to MS and (iii) low analytical throughput. Technologies for automation of SCP have recently gained attention to improve methods accuracy, sensitivity, throughput and in-depth and low-biased proteome analysis. In this minireview, we therefore overview the state-of-the-art of automation of SCP-MS sample preparation approaches.

Invadopodia Structure in 3D Environment Resolved by Near-Infrared Branding Protocol Combining Correlative Confocal and FIB-SEM Microscopy.

Cancer cell invasion through tissue barriers is the intrinsic feature of metastasis, the most life-threatening aspect of cancer. Detailed observation and analysis of cancer cell behaviour in a 3D environment is essential for a full understanding of the mechanisms of cancer cell invasion. The inherent limits of optical microscopy resolution do not allow to for in-depth observation of intracellular structures, such as invadopodia of invading cancer cells. The required resolution can be achieved using electron microscopy techniques such as FIB-SEM. However, visualising cells in a 3D matrix using FIB-SEM is challenging due to difficulties with localisation of a specific cell deep within the resin block. We have developed a new protocol based on the near-infrared branding (NIRB) procedure that extends the pattern from the surface grid deep inside the resin. This 3D burned pattern allows for precise trimming followed by targeted 3D FIB-SEM. Here we present detailed 3D CLEM results combining confocal and FIB-SEM imaging of cancer cell invadopodia that extend deep into the collagen meshwork.

Natural Compounds and PCL Nanofibers: A Novel Tool to Counteract Stem Cell Senescence.

Tissue homeostasis mainly depends on the activity of stem cells to replace damaged elements and restore tissue functions. Within this context, mesenchymal stem cells and fibroblasts are essential for maintaining tissue homeostasis in skin, in particular in the dermis. Modifications in collagen fibers are able to affect stem cell features. Skin properties can be significantly reduced after injuries or with aging, and stem cell niches, mainly comprising extracellular matrix (ECM), may be compromised. To this end, specific molecules can be administrated to prevent the aging process induced by UV exposure in the attempt to maintain a youngness phenotype. NanoPCL-M is a novel nanodevice able to control delivery of Mediterranean plant myrtle (Myrtus communis L.) extracts. In particular, we previously described that myrtle extracts, rich in bioactive molecules and nutraceuticals, were able to counteract senescence in adipose derived stem cells. In this study, we analyzed the effect of NanoPCL-M on skin stem cells (SSCs) and dermal fibroblasts in a dynamic cell culture model in order to prevent the effects of UV-induced senescence on proliferation and collagen depot. The BrdU assay results highlight the significantly positive effect of NanoPCL-M on the proliferation of both fibroblasts and SSCs. Our results demonstrate that-M is able to preserve SSCs features and collagen depot after UV-induced senescence, suggesting their capability to retain a young phenotype.

Microproteomic sample preparation.

Multiple applications of proteomics in life and health science, pathology and pharmacology, require handling size-limited cell and tissue samples. During proteomic sample preparation, analyte loss in these samples arises when standard procedures are used. Thus, specific considerations have to be taken into account for processing, that are summarised under the term microproteomics (µPs). Microproteomic workflows include: sampling (e.g., flow cytometry, laser capture microdissection), sample preparation (possible disruption of cells or tissue pieces via lysis, protein extraction, digestion in bottom-up approaches, and sample clean-up) and analysis (chromatographic or electrophoretic separation, mass spectrometric measurements and statistical/bioinformatic evaluation). All these steps must be optimised to reach wide protein dynamic ranges and high numbers of identifications. Under optimal conditions, sampling is adapted to the studied sample types and nature, sample preparation isolates and enriches the whole protein content, clean-up removes salts and other interferences such as detergents or chaotropes, and analysis identifies as many analytes as the instrumental throughput and sensitivity allow. In the suggested review, we present and discuss the current state in µP applications for processing of small number of cells (cell µPs) and microscopic tissue regions (tissue µPs).

An overview on the recent applications of agarose as a green biopolymer in micro-extraction-based sample preparation techniques.

Introducing a myriad array of chemicals in different industrial fields has made sample preparation inevitable for trace analysis. Classical extraction techniques such as solid phase extraction (SPE) and liquid-liquid extraction (LLE) techniques often suffer from tedious procedures (huge workload) and hazards to personnel and environment (samples and reagents are often user-unfriendly and processed in high amounts). For addressing these problems, microextraction techniques have been introduced. These systems benefit from using a minute amount of sample, reduced consumption of organic solvents, enhanced clean-up, high recovery and high enrichment factors. Moreover, approaches based on the use of natural materials have emerged during the last 10 years. Agarose is a natural biopolymer used as a green material in the form of gel-based separation medium. It has been recently utilized in the microextraction schemes. Easy fabrication, adjustability to get various dimensions and shapes, high inertness and biodegradability are of its main attributes. The present overview is focused on applications of agarose in solid phase microextraction (SPME), micro-solid phase extraction (µ-SPE) and liquid phase microextraction (LPME) - agarose film-liquid phase microextraction (AF-LPME) and gel electromembrane extraction (G-EME) since 2012. Besides, the pros and cons of agarose employment in the mentioned techniques will be described in depth.

Recent advances in robotic protein sample preparation for clinical analysis and other biomedical applications.

Discovery of new protein biomarker candidates has become a major research goal in the areas of clinical chemistry, analytical chemistry, and biomedicine. These important species constitute the molecular target when it comes to diagnosis, prognosis, and further monitoring of disease. However, their analysis requires powerful, selective and high-throughput sample preparation and product (analyte) characterisation approaches. In general, manual sample processing is tedious, complex and time-consuming, especially when large numbers of samples have to be processed (e.g., in clinical studies). Automation via microtiter-plate platforms involving robotics has brought improvements in high-throughput performance while comparable or even better precisions and repeatability (intra-day, inter-day) were achieved. At the same time, waste production and exposure of laboratory personnel to hazards were reduced. In comprehensive protein analysis workflows (e.g., liquid chromatography-tandem mass spectrometry analysis), sample preparation is an unavoidable step. This review surveys the recent achievements in automation of bottom-up and top-down protein and/or proteomics approaches. Emphasis is put on high-end multi-well plate robotic platforms developed for clinical analysis and other biomedical applications. The literature from 2013 to date has been covered.

The unfolded protein response controls endoplasmic reticulum stress-induced apoptosis of MCF-7 cells via a high dose of vitamin C treatment.

Recent in vitro studies have shown that vitamin C (Vit C) with pro-oxidative properties causes cytotoxicity of breast cancer cells by selective oxidative stress. However, the effect of Vit C in itself at different concentration levels on MCF-7 breast cancer cell line after 24 h, has not yet been described. We aimed to examine the effect of Vit C on the viability and signalling response of MCF-7/WT (MCF-7 wild-type) cells that were exposed to various concentrations (0.125-4 mM) of Vit C during 24 h. The cytotoxic effect of Vit C on MCF-7/VitC (MCF-7/WT after added 2 mM Vit C) was observed, resulting in a decrease of cell index after 12 h. Also, the cytotoxicity of Vit C (2 mM) after 24 h was confirmed by flow cytometry, i.e., increase of dead, late apoptotic, and depolarized dead MCF-7/VitC cells compared to MCF-7/WT cells. Moreover, changes in proteomic profile of MCF-7/VitC cells compared to the control group were investigated via label-free quantitative mass spectrometry and post-translational modification. Using bioinformatics assessment (i.e., iPathwayGuide and SPIA R packages), a significantly impacted pathway in MCF-7/VitC was identified, namely the protein processing in endoplasmic reticulum. The semi-quantitative change (log2fold change = 4.5) and autophosphorylation at Thr-446 of protein kinase (PKR) (involved in this pathway) indicates that PKR protein could be responsible for the unfolded protein response and inhibition of the cell translation during endoplasmic reticulum stress, and eventually, for cell apoptosis. These results suggest that increased activity of PKR (Thr-446 autophosphorylation) related to cytotoxic effect of Vit C (2 mM) may cause the MCF-7 cells death.

RHOA and mDia1 Promotes Apoptosis of Breast Cancer Cells Via a High Dose of Doxorubicin Treatment.

BACKGROUND: Transforming RhoA proteins (RHOA) and their downstream Diaphanous homolog 1 proteins (DIAPH1) or mDia1 participate in the regulation of actin cytoskeleton which plays critical role in cells, i.e., morphologic changes and apoptosis. METHODOLOGY: To determine the cell viability the real time cell analysis (RTCA) and flow cytometry were used. To perform proteomic analysis, the label-free quantitative method and post-translation modification by the nano-HPLC and ESI-MS ion trap mass analyser were used. RESULTS: The results of the cell viability showed an increase of dead cells (around 30 %) in MCF-7/DOX-1 (i.e., 1µM of doxorubicin was added to MCF-7/WT breast cancer cell line) compared to MCF-7/WT (control) after 24 h doxorubicin (DOX) treatment. The signalling pathway of the Regulation of actin cytoskeleton (p<0.0026) was determined, where RHOA and mDia1 proteins were up-regulated. Also, post-translational modification analysis of these proteins in MCF-7/DOX-1 cells revealed dysregulation of the actin cytoskeleton, specifically the collapse of actin stress fibbers due to phosphorylation of RHOA at serine 188 and mDia1 at serine 22, resulting in their deactivation and cell apoptosis. CONCLUSION: These results pointed to an assumed role of DOX to dysregulation of actin cytoskeleton and cell death.