Correlative nanomechanical profiling with super-resolution F-actin imaging reveals novel insights into mechanisms of cisplatin resistance in ovarian cancer cells

Exploiting mechanoregulation via FAK/YAP to overcome platinum resistance in ovarian cancer

Cancer cells mechanically interact with the tumor microenvironment during cancer development. Mechano-reciprocity has emerged as a crucial factor affecting anti-cancer drug resistance during adjuvant therapy. Here, we investigated the focal adhesion kinase (FAK)/Yes-associated protein (YAP) signaling axis as a prospective strategy for circumventing cisplatin resistance in ovarian cancer (OC). The Cancer Genome Atlas (TCGA) data analysis revealed that FAK overexpression significantly correlated with unfavorable clinical outcomes in patients with ovarian cancer. AFM indentation experiments showed that cell elasticity depends on FAK activity. Notably, the combination of FAK inhibition and cisplatin treatment led to a 69 % reduction in the IC50 of cisplatin. This combined treatment also increased apoptosis compared to the individual treatments, along with the upregulation of the pro-apoptotic factor BAX and cleaved PARP. Suppressing FAK expression sequestered YAP in the cytosol, potentially reducing cellular proliferation and promoting apoptosis. Moreover, reduced FAK expression sensitized drug-resistant OC cells to cisplatin treatment owing to a decrease in nuclear tension, allowing the relocation of YAP to the cytosol. In a mouse model, the co-administration of an FAK inhibitor and cisplatin significantly suppressed tumor growth and increased apoptotic events and DNA fragmentation. Our findings suggest that drug resistance can be attributed to the perturbation of mechanosensing signaling pathways, which drive the mechanical reinforcement of cancer cells. OC cells can restore their sensitivity to cisplatin treatment by strategically reducing YAP localization in the nucleus through FAK downregulation.

Nanotechnological Advances in the Diagnosis of Gynecological Cancers and Nanotheranostics

Gynecological cancers are one of the main causes of female mortality worldwide. Despite the various strategies to reduce mortality and improve quality of life, there are still many deficiencies in the diagnosis and treatment of gynecological cancers. One of the important steps to ensure optimal cancer treatment is the early detection of cancer cells and the use of drugs to reduce toxicity. Due to the increase in systemic toxicity and resistance to traditional and conventional diagnostic methods, new strategies, including nanotechnology, are being used to improve diagnosis and reduce the severity of the disease. Nanoparticles (NPs) provide exciting opportunities to improve Gynecological Cancers (GCs) diagnosis, particularly in the initial stages. In biomedical investigations and clinical settings, NPs can be used to increase the sensitivity and specificity of recognition and/or imaging of GCs with the help of their molecular and cellular processes. To design more efficient diagnostic NPs for gynecological cancer cells or tissues, determining the specific biomarkers is of great importance. NP-based imaging agents are another solution to trace cancer cells. This review highlights the potential of some NP-based diagnostic techniques in GC detection, which could be translated to clinical settings to improve patient care.

α-Catenin acetylation is essential for its stability and blocks its tumor suppressor effects in breast cancer through Yap1

α-Catenin plays a critical role in tissue integrity, repair, and embryonic development. However, the post-translational modifications of α-catenin and the correlative roles in regulating cancer progression remain unclear. Here, we report that α-catenin is acetylated by p300, and identify three acetylation sites, K45, K866, and K881. Conversely, α-catenin acetylation can be reversed by deacetylase HDAC6. Mechanistically, α-catenin acetylation releases the transcriptional coactivator Yes-associated protein 1 (Yap1) by blocking the interaction between α-catenin and Yap1, and promotes the accumulation of Yap1 in the nucleus. Through this mechanism, acetylation weakens the capacity of α-catenin to inhibit breast cancer cell proliferation and tumor growth in mice. Meanwhile, we show that CDDP induces acetylation of α-catenin, and acetylated α-catenin resists the apoptosis under CDDP conditions. Additionally, acetylation inhibits the proteasome-dependent degradation of α-catenin, thus enhancing the stability of α-catenin for storage. Taken together, our results demonstrate that α-catenin can be acetylated, an event that is key for the subcellular distribution of Yap1 and subsequent facilitation of breast tumorigenesis.

Indentation of living cells by AFM tips may not be what we thought!

The models used to calculate Young's moduli from atomic force microscopy (AFM) force curves consider the shape of the indentation. It is then assumed that the geometry of the indentation is identical to the geometry of the indenter, which has been verified for hard materials (E > 1 MPa). Based on this assumption, the force curves calculated by these models, for the same object with a given Young's modulus, are different if the indenter geometry is different. On the contrary, we observe experimentally that the force curves recorded on soft living cells, with pyramidal, spherical, or tipless indenters, are almost similar. This indicates that this basic assumption on the indentation geometry does not work for soft materials (E of the order of 5 kPa or less). This means that, in this case, the shape of the indentation is therefore different from the shape of the indenter. Indentation of living cells by AFM is not what we thought!

Exploring the Potential of Metal-Based Candidate Drugs as Modulators of the Cytoskeleton

During recent years, accumulating evidence suggested that metal-based candidate drugs are promising modulators of cytoskeletal and cytoskeleton-associated proteins. This was substantiated by the identification and validation of actin, vimentin and plectin as targets of distinct ruthenium(II)- and platinum(II)-based modulators. Despite this, structural information about molecular interaction is scarcely available. Here, we compile the scattered reports about metal-based candidate molecules that influence the cytoskeleton, its associated proteins and explore their potential to interfere in cancer-related processes, including proliferation, invasion and the epithelial-to-mesenchymal transition. Advances in this field depend crucially on determining binding sites and on gaining comprehensive insight into molecular drug-target interactions. These are key steps towards establishing yet elusive structure-activity relationships.

YAP at the Crossroads of Biomechanics and Drug Resistance in Human Cancer

Biomechanical forces are of fundamental importance in biology, diseases, and medicine. Mechanobiology is an emerging interdisciplinary field that studies how biological mechanisms are regulated by biomechanical forces and how physical principles can be leveraged to innovate new therapeutic strategies. This article reviews state-of-the-art mechanobiology knowledge about the yes-associated protein (YAP), a key mechanosensitive protein, and its roles in the development of drug resistance in human cancer. Specifically, the article discusses three topics: how YAP is mechanically regulated in living cells; the molecular mechanobiology mechanisms by which YAP, along with other functional pathways, influences drug resistance of cancer cells (particularly lung cancer cells); and finally, how the mechanical regulation of YAP can influence drug resistance and vice versa. By integrating these topics, we present a unified framework that has the potential to bring theoretical insights into the design of novel mechanomedicines and advance next-generation cancer therapies to suppress tumor progression and metastasis.

Nanomechanical Characterization of Ovarian Cancer Cell Lines as a Marker of Response to 2c Treatment

Epithelial ovarian cancers (EOCs) are a heterogeneous group of tumors with different molecular and clinical features. In past decades, few improvements have been achieved in terms of EOC management and treatment efficacy, such that the 5-year survival rate of patients remained almost unchanged. A better characterization of EOCs' heterogeneity is needed to identify cancer vulnerabilities, stratify patients and adopt proper therapies. The mechanical features of malignant cells are emerging as new biomarkers of cancer invasiveness and drug resistance that can further improve our knowledge of EOC biology and allow the identification of new molecular targets. In this study, we determined the inter and intra-mechanical heterogeneity of eight ovarian cancer cell lines and their association with tumor invasiveness and resistance to an anti-tumoral drug with cytoskeleton depolymerization activity (2c).

Nanomechanical Signatures in Glioma Cells Depend on CD44 Distribution in IDH1 Wild-Type but Not in IDH1R132H Mutant Early-Passage Cultures

Atomic force microscopy (AFM) recently burst into biomedicine, providing morphological and functional characteristics of cancer cells and their microenvironment responsible for tumor invasion and progression, although the novelty of this assay needs to coordinate the malignant profiles of patients' specimens to diagnostically valuable criteria. Applying high-resolution semi-contact AFM mapping on an extended number of cells, we analyzed the nanomechanical properties of glioma early-passage cell cultures with a different IDH1 R132H mutation status. Each cell culture was additionally clustered on CD44+/- cells to find possible nanomechanical signatures that differentiate cell phenotypes varying in proliferative activity and the characteristic surface marker. IDH1 R132H mutant cells compared to IDH1 wild-type ones (IDH1wt) characterized by two-fold increased stiffness and 1.5-fold elasticity modulus. CD44+/IDH1wt cells were two-fold more rigid and much stiffer than CD44-/IDH1wt ones. In contrast to IDH1 wild-type cells, CD44+/IDH1 R132H and CD44-/IDH1 R132H did not exhibit nanomechanical signatures providing statistically valuable differentiation of these subpopulations. The median stiffness depends on glioma cell types and decreases according to the following manner: IDH1 R132H mt (4.7 mN/m), CD44+/IDH1wt (3.7 mN/m), CD44-/IDH1wt (2.5 mN/m). This indicates that the quantitative nanomechanical mapping would be a promising assay for the quick cell population analysis suitable for detailed diagnostics and personalized treatment of glioma forms.

A nanomechanical strategy involving focal adhesion kinase for overcoming drug resistance in breast cancer

Despite implementation of nanomechanical studies in cancer research, studies on the nanomechanical aspects of drug resistance in cancer are lacking. Here, we established the mechanical signatures of drug-resistant breast cancer cells using atomic force microscopy-based indentation techniques and functionalized nanopatterned substrates (NPS). Additionally, we examined the expression of proteins pertinent to focal adhesions in order to elucidate the molecular signatures responsible for the acquisition of drug resistance in breast cancer cells. Drug-resistant breast cancer cells exhibited mechanical reinforcement, increased actin stress fibers, dysfunctional mechano-reciprocal interaction with the NPS, vinculin overexpression, and improved focal adhesion kinase (FAK) activity. Owing to differences in FAK activation upon co-treatment with a FAK inhibitor, the drug-resistant breast cancer cells were eradicated more efficiently than invasive breast cancer cells having pro-survival activity. These findings demonstrated the potential of a novel co-treatment regimen using FAK inhibitors for overcoming drug resistance in breast cancer cells.

Cancer cell mechanobiology: a new frontier for cancer research

The study of physical and mechanical features of cancer cells, or cancer cell mechanobiology, is a new frontier in cancer research. Such studies may enhance our understanding of the disease process, especially mechanisms associated with cancer cell invasion and metastasis, and may help the effort of developing diagnostic biomarkers and therapeutic drug targets. Cancer cell mechanobiological changes are associated with the complex interplay of activation/inactivation of multiple signaling pathways, which can occur at both the genetic and epigenetic levels, and the interactions with the cancer microenvironment. It has been shown that metastatic tumor cells are more compliant than morphologically similar benign cells in actual human samples. Subsequent studies from us and others further demonstrated that cell mechanical properties are strongly associated with cancer cell invasive and metastatic potential, and thus may serve as a diagnostic marker of detecting cancer cells in human body fluid samples. In this review, we provide a brief narrative of the molecular mechanisms underlying cancer cell mechanobiology, the technological platforms utilized to study cancer cell mechanobiology, the status of cancer cell mechanobiological studies in various cancer types, and the potential clinical applications of cancer cell mechanobiological study in cancer early detection, diagnosis, and treatment.

Influence of ROCK Pathway Manipulation on the Actin Cytoskeleton Height

The actin cytoskeleton with its dynamic properties serves as the driving force for the movement and division of cells and gives the cell shape and structure. Disorders in the actin cytoskeleton occur in many diseases. Deeper understanding of its regulation is essential in order to better understand these biochemical processes. In our study, we use metal-induced energy transfer (MIET) as a tool to quantitatively examine the rarely considered third dimension of the actin cytoskeleton with nanometer accuracy. In particular, we investigate the influence of different drugs acting on the ROCK pathway on the three-dimensional actin organization. We find that cells treated with inhibitors have a lower actin height to the substrate while treatment with a stimulator for the ROCK pathway increases the actin height to the substrate, while the height of the membrane remains unchanged. This reveals the precise tuning of adhesion and cytoskeleton tension, which leads to a rich three-dimensional structural behaviour of the actin cytoskeleton. This finetuning is differentially affected by either inhibition or stimulation. The high axial resolution shows the importance of the precise finetuning of the actin cytoskeleton and the disturbed regulation of the ROCK pathway has a significant impact on the actin behavior in the z dimension.

A naphthalimide-based peptide conjugate for concurrent imaging and apoptosis induction in cancer cells by utilizing endogenous hydrogen sulfide

The excessive production of endogenous hydrogen sulfide (H2S) in cancer cells leads to enhanced tumor growth and metastasis. On the other hand, decreased endogenous H2S suppresses tumor growth. The reported approaches for inhibiting tumor growth are selective silencing of the tumor-promoting genes and pharmacological inhibition of these proteins. To enhance the antitumor efficacy of frontline chemotherapeutic agents, herein, we synthesized a highly sensitive endogenous H2S responsive fluorescent probe, i.e., a hydrogen sulfide-sensing naphthalimide-based peptide conjugate (HSNPc), which showed selective inhibition of proliferation of cancer cells due to apoptosis induction. Furthermore, HSNPc suppressed the glycolytic reserve, a critical energy source for the proliferation of cancer cells. HSNPc also decreased the Young's modulus of HeLa cells compared to the control cells, which demonstrated a direct relation between cell apoptosis and cell stiffness. Taken together, we demonstrated the dual function of detection and killing of cancer cells by HSNPc that can be likened to a theranostic role.

Integrin α5 mediates intrinsic cisplatin resistance in three-dimensional nasopharyngeal carcinoma spheroids via the inhibition of phosphorylated ERK /caspase-3 induced apoptosis

Nasopharyngeal carcinoma (NPC) originates in the nasopharynx epithelium. Although concurrent chemoradiation therapy followed by chemotherapy is considered as an effective treatment, there is substantial drug resistance in locally advanced NPC patients. One major contributor to the chemoresistance includes aberrant expression of cell adhesion molecules, such as integrin α and β subunits, giving rise to cell adhesion-mediated drug resistance. Thus, the aim of this study was to investigate the effect of integrin α5 on the development of intrinsic cisplatin resistance in NPC and the associated underlying mechanisms using in vitro three-dimensional (3D) spheroid models, as well as induced cisplatin-resistant NPC (NPCcisR). We demonstrated that established 3D highly- (5-8F) and lowly- (6-10B) metastatic NPC spheroids overexpressed integrin α5 and aggravated their resistance to cisplatin. Besides, enhanced integrin α5 resulted in substantially reduced growth, corresponding to G₀/G₁ and G₂/M cell cycle arrest. In addition, 5-8FcisR and 6-10BcisR cells in 3D forms synergistically strengthened endurance of their spheroids to cisplatin treatment as observed by increased resistance index (RI) and decreased apoptosis. Mechanistically, the aberrantly expressed integrin α5 decreased drug susceptibility in NPC spheroids by inactivating ERK and inhibition of caspase-3 inducing apoptosis. Furthermore, the effect of integrin α5 inducing intrinsic resistance was verified via treatment with ATN-161, a peptide inhibitor for integrin α5β1. The results showed dramatic reduction in integrin α5 expression, reversal of ERK phosphorylation and caspase-3 cleavage, together with elevated cisplatin sensitivity, indicating regulation of innate drug resistance via integrin α5. Taken together, our findings suggest that integrin α5 could act as a promising target to enhance the chemotherapeutic sensitivity in NPC.

LINC00261 Suppresses Cisplatin Resistance of Esophageal Squamous Cell Carcinoma Through miR-545-3p/MT1M Axis

To improve the survival rate and cure rate of patients, it is necessary to find a new treatment scheme according to the molecular composition of (ESCC) in esophageal squamous cell carcinoma. Long non-coding RNAs (lncRNAs) regulate the progression of ESCC by various pathophysiological pathways. We explored the possible function of the lncRNA LINC00261 (LINC00261) on cisplatin (DDP) resistance of ESCC and its relative molecular mechanisms. In the study, we found that LINC00261 was downregulated in ESCC tissues, cell lines, and DDP-resistant ESCC patients. Besides, overexpression of LINC00261 not only inhibited cell proliferation, and DDP resistance but also promotes cell apoptosis. Further mechanistic research showed that LINC00261 sponged miR-545-3p which was negatively correlated with the expression of LINC00261. In addition, functional experiments revealed that upregulation of miR-766-5p promoted proliferation and enhanced DDP resistance. Subsequently, MT1M was testified to be the downstream target gene of miR-545-3p. Rescue experiments revealed that overexpression of MT1M largely restores miR-545-3p mimics-mediated function on ESCC progression. Our results demonstrate that the LINC00261 suppressed the DDP resistance of ESCC through miR-545-3p/MT1M axis.

Proteomic Analysis of the Non-genetic Response to Cisplatin in Lung Cancer Cells

BACKGROUND

Drug resistance is the main cause of therapy failure in advanced lung cancer. Although non-genetic mechanisms play important roles in tumor chemoresistance, drug-induced epigenetic reprogramming is still poorly understood.

MATERIALS AND METHODS

The A549 cell line was used to generate cells with non-genetic resistance to cisplatin (CDDP), namely A549/CDDP cells. Bioorthogonal non-canonical amino acid tagging (BONCAT) and mass spectrometry were used to identify proteins modulated by CDDP in A549 and A549/CDDP cells.

RESULTS

Proteins related to proteostasis, telomere maintenance, cell adhesion, cytoskeletal remodeling, and cell redox homeostasis were found enriched in both cell lines upon CDDP exposure. On the other hand, proteins involved in drug response, metabolic pathways and mRNA processing and splicing were up-regulated by CDDP only in A549/CDDP cells.

CONCLUSION

Our study revealed proteome dynamics involved in the non-genetic response to CDDP, pointing out potential targets to monitor and overcome epigenetic resistance in lung cancer.

Actin cytoskeleton deregulation confers midostaurin resistance in FLT3-mutant acute myeloid leukemia

The presence of FMS-like tyrosine kinase 3-internal tandem duplication (FLT3-ITD) is one of the most frequent mutations in acute myeloid leukemia (AML) and is associated with an unfavorable prognosis. FLT3 inhibitors, such as midostaurin, are used clinically but fail to entirely eradicate FLT3-ITD + AML. This study introduces a new perspective and highlights the impact of RAC1-dependent actin cytoskeleton remodeling on resistance to midostaurin in AML. RAC1 hyperactivation leads resistance via hyperphosphorylation of the positive regulator of actin polymerization N-WASP and antiapoptotic BCL-2. RAC1/N-WASP, through ARP2/3 complex activation, increases the number of actin filaments, cell stiffness and adhesion forces to mesenchymal stromal cells (MSCs) being identified as a biomarker of resistance. Midostaurin resistance can be overcome by a combination of midostaruin, the BCL-2 inhibitor venetoclax and the RAC1 inhibitor Eht1864 in midostaurin-resistant AML cell lines and primary samples, providing the first evidence of a potential new treatment approach to eradicate FLT3-ITD + AML.

Garitano-Trojaola et al. used a combination of human acute myeloid leukemia (AML) cell lines and primary samples to show that RAC1-dependent actin cytoskeleton remodeling through BCL2 family plays a key role in resistance to the FLT3 inhibitor, Midostaurin in AML. They showed that by targeting RAC1 and BCL2, Midostaurin resistance was diminished, which potentially paves the way for an innovate treatment approach for FLT3 mutant AML.

GTPases, genome, actin: A hidden story in DNA damage response and repair mechanisms

The classical small Rho GTPase (Rho, Rac, and Cdc42) protein family is mainly responsible for regulating cell motility and polarity, membrane trafficking, cell cycle control, and gene transcription. Cumulative recent evidence supports important roles for these proteins in the maintenance of genomic stability. Indeed, DNA damage response (DDR) and repair mechanisms are some of the prime biological processes that underlie several disease phenotypes, including genetic disorders, cancer, senescence, and premature aging. Many reports guided by different experimental approaches and molecular hypotheses have demonstrated that, to some extent, direct modulation of Rho GTPase activity, their downstream effectors, or actin cytoskeleton regulation contribute to these cellular events. Although much attention has been paid to this family in the context of canonical actin cytoskeleton remodeling, here we provide a contextualized review of the interplay between Rho GTPase signaling pathways and the DDR and DNA repair signaling components. Interesting questions yet to be addressed relate to the spatiotemporal dynamics of this collective response and whether it correlates with different subcellular pools of Rho GTPases. We highlight the direct and indirect targets, some of which still lack experimental validation data, likely associated with Rho GTPase activation that provides compelling evidence for further investigation in DNA damage-associated events and with potential therapeutic applications in translational medicine.

DNA damage alters nuclear mechanics through chromatin reorganization

DNA double-strand breaks drive genomic instability. However, it remains unknown how these processes may affect the biomechanical properties of the nucleus and what role nuclear mechanics play in DNA damage and repair efficiency. Here, we have used Atomic Force Microscopy to investigate nuclear mechanical changes, arising from externally induced DNA damage. We found that nuclear stiffness is significantly reduced after cisplatin treatment, as a consequence of DNA damage signalling. This softening was linked to global chromatin decondensation, which improves molecular diffusion within the organelle. We propose that this can increase recruitment for repair factors. Interestingly, we also found that reduction of nuclear tension, through cytoskeletal relaxation, has a protective role to the cell and reduces accumulation of DNA damage. Overall, these changes protect against further genomic instability and promote DNA repair. We propose that these processes may underpin the development of drug resistance.

Single Cell Mechanotype and Associated Molecular Changes in Urothelial Cell Transformation and Progression

Cancer cell mechanotype changes are newly recognized cancer phenotypic events, whereas metastatic cancer cells show decreased cell stiffness and increased deformability relative to normal cells. To further examine how cell mechanotype changes in early stages of cancer transformation and progression, an in vitro multi-step human urothelial cell carcinogenic model was used to measure cellular Young's modulus, deformability, and transit time using single-cell atomic force microscopy, microfluidic-based deformability cytometry, and quantitative deformability cytometry, respectively. Measurable cell mechanotype changes of stiffness, deformability, and cell transit time occur early in the transformation process. As cells progress from normal, to preinvasive, to invasive cells, Young's modulus of stiffness decreases and deformability increases gradually. These changes were confirmed in three-dimensional cultured microtumor masses and urine exfoliated cells directly from patients. Using gene screening and proteomics approaches, we found that the main molecular pathway implicated in cell mechanotype changes appears to be epithelial to mesenchymal transition.

The Relationship Between Actin Cytoskeleton and Membrane Transporters in Cisplatin Resistance of Cancer Cells

Cisplatin [cis-diamminedichloroplatinum (II)] is a platinum-based anticancer drug widely used for the treatment of various cancers. It forms interstrand and intrastrand cross-linking with DNA and block DNA replication, resulting in apoptosis. On the other hand, intrinsic and acquired cisplatin resistance restricts its therapeutic effects. Although some studies suggest that dramatic epigenetic alternations are involved in the resistance triggered by cisplatin, the mechanism is complicated and remains poorly understood. Recent studies reported that cytoskeletal structures regulate cisplatin sensitivity and that activities of membrane transporters contribute to the development of resistance to cisplatin. Therefore, we focus on the roles of actin filaments and membrane transporters in cisplatin-induced apoptosis. In this review, we summarize the relationship between actin cytoskeleton and membrane transporters in the cisplatin resistance of cancer cells.

Pristine Cu-MOF Induces Mitotic Catastrophe and Alterations of Gene Expression and Cytoskeleton in Ovarian Cancer Cells

Metals-organic frameworks (MOFs) have been widely explored in biomedicine, mostly in drug delivery, biosensing, and bioimaging due to their large surface area, tunable porosity, readily chemical functionalization, and good biocompatibility. However, the underlining cellular mechanisms controlling the process for MOF cytotoxicity remains almost completely unknown. Here, we demonstrate that pristine Cu-MOF without any loaded drug selectively inhibited ovarian cancer mainly through promoting tubulin polymerization and destroying the cell actin cytoskeleton (F-actin) to trigger the mitotic catastrophe, accompanying by conventional programmed cell death. To our knowledge, this is the first report claiming that mitotic catastrophe may be an explaining mechanism of MOF cytotoxicity. Cu-MOF with an intrinsic protease-like activity also hydrolyzed cellular cytoskeleton proteins (F-actin). The RNA sequencing data indicated the differential expressional mRNA of cell proliferation and actin cytoskeleton (ACTA2, ACTN3, FSCN2, and SCIN) and mitotic spindles (PLK1 and TPX2) related genes. We found that Cu-MOF as a promising candidate in the disruption of cellular cytoskeleton and the change of the gene expression could be actin altering and antimitotic agents against cancer cells, allowing for fundamental biological and biophysical studies of MOFs.

Rho GTPases in Gynecologic Cancers: In-Depth Analysis toward the Paradigm Change from Reactive to Predictive, Preventive, and Personalized Medical Approach Benefiting the Patient and Healthcare

Rho guanosine triphospatases (GTPases) resemble a conserved family of GTP-binding proteins regulating actin cytoskeleton dynamics and several signaling pathways central for the cell. Rho GTPases create a so-called Ras-superfamily of GTPases subdivided into subgroups comprising at least 20 members. Rho GTPases play a key regulatory role in gene expression, cell cycle control and proliferation, epithelial cell polarity, cell migration, survival, and apoptosis, among others. They also have tissue-related functions including angiogenesis being involved in inflammatory and wound healing processes. Contextually, any abnormality in the Rho GTPase function may result in severe consequences at molecular, cellular, and tissue levels. Rho GTPases also play a key role in tumorigenesis and metastatic disease. Corresponding mechanisms include a number of targets such as kinases and scaffold/adaptor-like proteins initiating GTPases-related signaling cascades. The accumulated evidence demonstrates the oncogenic relevance of Rho GTPases for several solid malignancies including breast, liver, bladder, melanoma, testicular, lung, central nervous system (CNS), head and neck, cervical, and ovarian cancers. Furthermore, Rho GTPases play a crucial role in the development of radio- and chemoresistance e.g. under cisplatin-based cancer treatment. This article provides an in-depth overview on the role of Rho GTPases in gynecological cancers, highlights relevant signaling pathways and pathomechanisms, and sheds light on their involvement in tumor progression, metastatic spread, and radio/chemo resistance. In addition, insights into a spectrum of novel biomarkers and innovative approaches based on the paradigm shift from reactive to predictive, preventive, and personalized medicine are provided.

Single Cell Hydrodynamic Stretching and Microsieve Filtration Reveal Genetic, Phenotypic and Treatment-Related Links to Cellular Deformability

Deformability is shown to correlate with the invasiveness and metastasis of cancer cells. Recent studies suggest epithelial-to-mesenchymal transition (EMT) might enable cancer metastasis. However, the correlation of EMT with cancer cell deformability has not been well elucidated. Cellular deformability could also help evaluate the drug response of cancer cells. Here, we combine hydrodynamic stretching and microsieve filtration to study cellular deformability in several cellular models. Hydrodynamic stretching uses extensional flow to rapidly quantify cellular deformability and size with high throughput at the single cell level. Microsieve filtration can rapidly estimate relative deformability in cellular populations. We show that colorectal cancer cell line RKO with the mesenchymal-like feature is more flexible than the epithelial-like HCT116. In another model, the breast epithelial cells MCF10A with deletion of the TP53 gene are also significantly more deformable compared to their isogenic wildtype counterpart, indicating a potential genetic link to cellular deformability. We also find that the drug docetaxel leads to an increase in the size of A549 lung cancer cells. The ability to associate mechanical properties of cancer cells with their phenotypes and genetics using single cell hydrodynamic stretching or the microsieve may help to deepen our understanding of the basic properties of cancer progression.

Rho GTPases: Promising candidates for overcoming chemotherapeutic resistance

Despite therapeutic advances, resistance to chemotherapy remains a major challenge to patients with malignancies. Rho GTPases are essential for the development and progression of various diseases including cancer, and a vast number of studies have linked Rho GTPases to chemoresistance. Therefore, understanding the underlying mechanisms can expound the effects of Rho GTPases towards chemotherapeutic agents, and targeting Rho GTPases is a promising strategy to downregulate the chemo-protective pathways and overcome chemoresistance. Importantly, exceptions in certain biological conditions and interactions among the members of Rho GTPases should be noted. In this review, we focus on the role of Rho GTPases, particularly Rac1, in regulating chemoresistance and provide an overview of their related mechanisms and available inhibitors, which may offer novel options for future targeted cancer therapy.

Molecular Imaging in Oncology: Advanced Microscopy Techniques

Preclinical studies usually require high levels of morphological, functional, and biochemical information at subcellular resolution. This type of information cannot be obtained from clinical imaging techniques, such as MRI, PET/CT, or US. Luckily, many microscopy techniques exist that can offer this information, also for malignant tissues and therapeutic approaches. In this overview, we discuss the various advanced optical microscopy techniques and their applications in oncological research. After a short introduction in Sect. 16.1, we continue in Sect. 16.2 with a discussion on fluorescent labelling strategies, followed in Sect. 16.3 by an in-depth description of confocal, light-sheet, two-photon, and super-resolution microscopy. We end in Sect. 16.4 with a focus on the applications, specifically in oncology.

Harnessing the Power of Optical Microscopic and Macroscopic Imaging for Natural Products as Cancer Therapeutics

Natural products (NPs) are an important source for new drug discovery over the past decades, which have been demonstrated to be effectively used in cancer prevention, treatment, and adjuvant therapy. Many methods, such as the genomic and metabolomic approaches, immunochemistry, mass spectrometry, and chromatography, have been used to study the effects of NPs on cancer as well as themselves. Because of the advantages in specificity, sensitivity, high throughput, and cost-effectiveness, optical imaging (OI) approaches, including optical microscopic imaging and macroscopic imaging techniques have also been applied in the studies of NPs. Optical microscopic imaging can observe NPs as cancer therapeutics at the cellular level and analyze its cytotoxicity and mechanism of action. Optical macroscopic imaging observes the distribution, metabolic pathway, and target lesions of NPs in vivo, and evaluates NPs as cancer therapeutics at the whole-body level in small living animals. This review focuses on the recent advances in NPs as cancer therapeutics, with particular emphasis on the powerful use of optical microscopic and macroscopic imaging techniques, including the studies of observation of ingestion by cells, anticancer mechanism, and in vivo delivery. Finally, we prospect the wider application and future potential of OI approaches in NPs as cancer therapeutics.

An optical study of drug resistance detection in endometrial cancer cells by dynamic and quantitative phase imaging

Platinum chemosensitivity detection plays a vital role during endometrial cancer treatment because chemotherapy responses have profound influences on patient's prognosis. Although several methods can be used to detect drug resistance characteristics, studies on detecting drug sensitivity based on dynamic and quantitative phase imaging of cancer cells are rare. In this study, digital holographic microscopy was applied to distinguish drug-resistant and nondrug-resistant endometrial cancer cells. Based on the reconstructed phase images, temporal evolutions of cell height (CH), cell projected area (CPA) and cell volume were quantitatively measured. The results show that change rates of CH and CPA were significantly different between drug-resistant and nondrug-resistant endometrial cancer cells. Furthermore, the results demonstrate that morphological characteristics have the potential to be utilized to distinguish the drug sensitivity of endometrial cancer cells, and it may provide new perspectives to establish optical methods to detect drug sensitivity and guide chemotherapy in endometrial cancer.

Piezoelectric needle sensor reveals mechanical heterogeneity in human thyroid tissue lesions

Palpable thyroid lesions are common, and although mostly benign, lethal malignant nodules do occur and may be difficult to differentiate. Here, we introduce the use of a piezoelectric system called Smart-touch fine needle (or STFN) mounted directly onto conventional biopsy needles, to evaluate abnormal tissues, through quantitative real-time measurements of variations in tissue stiffness as the needle penetrates tissue. Using well-characterized biomaterials of known stiffness and explanted animal tissue models, we first established experimental protocols for STFN measures on biological tissues, as well as optimized device design for high signal-to-noise ratio. Freshly excised patient thyroids with varying fibrotic and malignant potential revealed discrete variations in STFN based tissue stiffness/stiffness heterogeneity and correlated well with final histopathology. Our piezoelectric needle sensor reveals mechanical heterogeneity in thyroid tissue lesions and provides a foundation for the design of hand-held tools for the rapid, mechano-profiling of malignant lesions in vivo while performing fine needle aspiration (FNA).

The roles of nuclear focal adhesion kinase (FAK) on Cancer: a focused review

FAK is a tyrosine kinase overexpressed in cancer cells and plays an important role in the progression of tumors to a malignant phenotype. Except for its typical role as a cytoplasmic kinase downstream of integrin and growth factor receptor signaling, related studies have shown new aspects of the roles of FAK in the nucleus. FAK can promote p53 degradation through ubiquitination, leading to cancer cell growth and proliferation. FAK can also regulate GATA4 and IL-33 expression, resulting in reduced inflammatory responses and immune escape. These findings establish a new model of FAK from the cytoplasm to the nucleus. Activated FAK binds to transcription factors and regulates gene expression. Inactive FAK synergizes with different E3 ligases to promote the turnover of transcription factors by enhancing ubiquitination. In the tumor microenvironment, nuclear FAK can regulate the formation of new blood vessels, affecting the tumor blood supply. This article reviews the roles of nuclear FAK in regulating gene expression. In addition, the use of FAK inhibitors to target nuclear FAK functions will also be emphasized.

Cisplatin enhances cell stiffness and decreases invasiveness rate in prostate cancer cells by actin accumulation

We focused on the biomechanical and morphological characteristics of prostate cancer cells and their changes resulting from the effect of docetaxel, cisplatin, and long-term zinc supplementation. Cell population surviving the treatment was characterized as follows: cell stiffness was assessed by atomic force microscopy, cell motility and invasion capacity were determined by colony forming assay, wound healing assay, coherence-controlled holographic microscopy, and real-time cell analysis. Cells of metastatic origin exhibited lower height than cells derived from the primary tumour. Cell dry mass and CAV1 gene expression followed similar trends as cell stiffness. Docetaxel- and cisplatin-surviving cells had higher stiffness, and decreased motility and invasive potential as compared to non-treated cells. This effect was not observed in zinc(II)-treated cells. We presume that cell stiffness changes may represent an important overlooked effect of cisplatin-based anti-cancer drugs. Atomic force microscopy and confocal microscopy data images used in our study are available for download in the Zenodo repository ( https://zenodo.org/ , Digital Object Identifiers:10.5281/zenodo.1494935).

Cisplatin-Membrane Interactions and Their Influence on Platinum Complexes Activity and Toxicity

Cisplatin and other platinum(II) analogs are widely used in clinical practice as anti-cancer drugs for a wide range of tumors. The primary mechanism by which they exert their action is through the formation of adducts with genomic DNA. However, multiple cellular targets by platinum(II) complexes have been described. In particular, the early events occurring at the plasma membrane (PM), i.e., platinum-membrane interactions seem to be involved in the uptake, cytotoxicity and cell-resistance to cisplatin. In fact, PM influences signaling events, and cisplatin-induced changes on membrane organization and fluidity were shown to activate apoptotic pathways. This review critically discusses the sequence of events caused by lipid membrane-platinum interactions, with emphasis on the mechanisms that lead to changes in the biophysical properties of the membranes (e.g., fluidity and permeability), and how these correlate with sensitivity and resistance phenotypes of cells to platinum(II) complexes.

Chemotherapeutic resistance: a nano-mechanical point of view

Chemotherapeutic resistance is one of the main obstacles for cancer remission. To understand how cancer cells acquire chemotherapeutic resistance, biochemical studies focusing on drug target alteration, altered cell proliferation, and reduced susceptibility to apoptosis were performed. Advances in nano-mechanobiology showed that the enhanced mechanical deformability of cancer cells accompanied by cytoskeletal alteration is a decisive factor for cancer development. Furthermore, atomic force microscopy (AFM)–based nano-mechanical studies showed that chemotherapeutic treatments reinforced the mechanical stiffness of drug-sensitive cancer cells. However, drug-resistant cancer cells did not show such mechanical responses following chemotherapeutic treatments. Interestingly, drug-resistant cancer cells are mechanically heterogeneous, with a subpopulation of resistant cells showing higher stiffness than their drug-sensitive counterparts. The signaling pathways involving Rho, vinculin, and myosin II were found to be responsible for these mechanical alterations in drug-resistant cancer cells. In the present review, we highlight the mechanical aspects of chemotherapeutic resistance, and suggest how mechanical studies can contribute to unravelling the multifaceted nature of chemotherapeutic resistance.

Cortical Actin Dynamics in Endothelial Permeability

The pulmonary endothelial cell forms a critical semi-permeable barrier between the vascular and interstitial space. As part of the blood-gas barrier in the lung, the endothelium plays a key role in normal physiologic function and pathologic disease. Changes in endothelial cell shape, defined by its plasma membrane, determine barrier integrity. A number of key cytoskeletal regulatory and effector proteins including non-muscle myosin light chain kinase, cortactin, and Arp 2/3 mediate actin rearrangements to form cortical and membrane associated structures in response to barrier enhancing stimuli. These actin formations support and interact with junctional complexes and exert forces to protrude the lipid membrane to and close gaps between individual cells. The current knowledge of these cytoskeletal processes and regulatory proteins are the subject of this review. In addition, we explore novel advancements in cellular imaging that are poised to shed light on the complex nature of pulmonary endothelial permeability.

Atomic force microscopy correlates antimetastatic potentials of HepG2 cell line with its redox/energy status: effects of curcumin and Khaya senegalensis

OBJECTIVE

The fatality of cancer is mostly dependent on the possibility of occurrence of metastasis. Thus, if the development of metastasis can be prevented through novel therapeutic strategies targeted against this process, then the success of cancer treatment will drastically increase. In this study, therefore, we evaluated the antimetastatic potentials of an extract of Khaya senegalensis and curcumin on the metastatic liver cell line HepG2, and also assessed the anticancer property of the extract.

METHODS

Cells were cultured and treated with graded concentrations of test substances for 24, 48, or 72 h with provisions made for negative controls. Treated cells were assessed as follows: nanotechnologically - atomic force microscopy (AFM) was used to determine cell stiffness; biochemically - cell cytotoxicity, glutathione level and adenosine triphosphate status, caspase activation and mitochondrial toxicity were considered; and microbiologically - a carrot disk assay was used to assess the anticancer property of the extract of K. senegalensis.

RESULTS

Curcumin and K. senegalensis increased the cell stiffness by 2.6- and 4.0-fold respectively, indicating their antimetastatic effects. Corresponding changes in redox (glutathione level) and energy (adenosine triphosphate) status of the cells were also demonstrated. Further mechanistic studies indicated that curcumin was not mitotoxic in HepG2 cells unlike the K. senegalensis extract. In addition, the extract potently inhibited the Agrobacterium tumefaciens-induced genetic transformation based on carrot disk assay.

CONCLUSION

Cell elasticity measurement data, using AFM, strongly suggested, for the first time, that both curcumin and the extract of K. senegalensis exhibited antimetastatic properties on HepG2 cells.

HIC1 and RassF1A Methylation Attenuates Tubulin Expression and Cell Stiffness in Cancer

Cell stiffness is a potential biomarker for monitoring cellular transformation, metastasis, and drug resistance development. Environmental factors relayed into the cell may result in formation of inheritable markers (e.g., DNA methylation), which provide selectable advantages (e.g., tumor development-favoring changes in cell stiffness). We previously demonstrated that targeted methylation of two tumor suppressor genes, hypermethylated in cancer 1 (HIC1) and Ras-association domain family member 1A (RassF1A), transformed mesenchymal stem cells (MSCs). Here, transformation-associated cytoskeleton and cell stiffness changes were evaluated. Atomic force microscopy (AFM) was used to detect cell stiffness, and immunostaining was used to measure cytoskeleton expression and distribution in cultured cells as well as in vivo. HIC1 and RassF1A methylation (me_HR)-transformed MSCs developed into tumors that clonally expanded in vivo. In me_HR-transformed MSCs, cell stiffness was lost, tubulin expression decreased, and F-actin was disorganized; DNA methylation inhibitor treatment suppressed their tumor progression, but did not fully restore their F-actin organization and stiffness. Thus, me_HR-induced cell transformation was accompanied by the loss of cellular stiffness, suggesting that somatic epigenetic changes provide inheritable selection markers during tumor propagation, but inhibition of oncogenic aberrant DNA methylation cannot restore cellular stiffness fully. Therefore, cell stiffness is a candidate biomarker for cells' physiological status.

Mechanical Alteration Associated With Chemotherapeutic Resistance of Breast Cancer Cells

Background

The mechanical deformability of cancer cells has attracted particular attention as an emerging biomarker for the prediction of anti-cancer drug sensitivity. Nevertheless, it has not been possible to establish a general rubric for the identification of drug susceptibility in breast cancer cells from a mechanical perspective. In the present study, we investigated the mechanical alteration associated with resistance to adjuvant therapy in breast cancer cells.

Methods

We performed an ‘atomic force microscopy (AFM)-based nanomechanical study’ on ‘drug-sensitive (MCF-7)’ and ‘drug-resistant (MCF-7/ADR)’ breast cancer cells. We also conducted cell viability tests to evaluate the difference in doxorubicin responsiveness between two breast cancer cell lines. We carried out a wound closure experiment to investigate the motility changes associated with chemotherapeutic resistance. To elucidate the changes in molecular alteration that accompany chemotherapeutic resistance, we investigated the expression of vinculin and integrin-linked kinase-1–which are proteins involved in substrate adhesion and the actin cytoskeleton–using Western blotting analysis.

Results

A MTT assay confirmed that the dose-dependent efficacy of doxorubicin was reduced in MCF-7/ADR cells compared to that in MCF-7 cells. The wound assay revealed enhanced two-dimensional motility in the MCF-7/ADR cells. The AFM mechanical assay showed evidence that the drug-resistant breast cancer cells exhibited a significant decrease in mechanical deformability compared to their drug-sensitive counterparts. The mechanical alteration in the MCF-7/ADR cells was accompanied by upregulated vinculin expression.

Conclusions

The obtained results manifestly showed that the altered mechanical signatures–including mechanical deformability and motility–were closely related with drug resistance in the breast cancer cells. We believe that this investigation has improved our understanding of the chemotherapeutic susceptibility of breast cancer cells.

Low-level shear stress promotes migration of liver cancer stem cells via the FAK-ERK1/2 signalling pathway

Cancer stem cells (CSCs) are a small subpopulation of tumour cells that have been proposed to be responsible for cancer initiation, chemotherapy resistance and cancer recurrence. Shear stress activated cellular signalling is involved in cellular migration, proliferation and differentiation. However, little is known about the effects of shear stress on the migration of liver cancer stem cells (LCSCs). Here, we studied the effects of shear stress that are generated from a parallel plated flow chamber system, on LCSC migration and the activation of focal adhesion kinase (FAK) and extracellular signal regulated kinase1/2 (ERK1/2), using transwell assay and western blot, respectively. We found that 2 dyne/cm² shear stress loading for 6 h promotes LCSC migration and activation of the FAK and ERK1/2 signalling pathways, whereas treatment with the FAK phosphorylation inhibitor PF573228 or the ERK1/2 phosphorylation inhibitor PD98059 suppressed the shear stress-promoted migration, indicating the involvement of FAK and ERK1/2 activation in shear stress-induced LCSC migration. Additionally, atomic force microscopy (AFM) analysis showed that shear stress lowers LCSC stiffness via the FAK and ERK1/2 pathways, suggesting that the mechanism by which shear stress promotes LCSC migration might partially be responsible for the decrease in cell stiffness. Further experiments focused on the role of the actin cytoskeleton, demonstrating that the F-actin filaments in LCSCs are less well-defined after shear stress treatment, providing an explanation for the reduction in cell stiffness and the promotion of cell migration. Overall, our study demonstrates that shear stress promotes LCSC migration through the activation of the FAK-ERK1/2 signalling pathways, which further results in a reduction of organized actin and softer cell bodies.

Icmt inhibition exerts anti-angiogenic and anti-hyperpermeability activities impeding malignant pleural effusion

Small GTPases are pivotal regulators of several aspects of tumor progression. Their implication in angiogenesis, vascular permeability and tumor-associated inflammatory responses is relevant to the pathobiology of Malignant Pleural Effusion (MPE). Inhibition of isoprenylcysteine carboxylmethyltransferase (Icmt) abrogates small GTPase activation. We therefore hypothesized that cysmethynil, an Icmt inhibitor would limit pleural fluid accumulation in two models, a lung-adenocarcinoma and a mesothelioma-induced MPE. Cysmethynil significantly reduced MPE volume in both models and tumor burden in the adenocarcinoma model. It inhibited pleural vascular permeability and tumor angiogenesis in vivo and reduced endothelial cell proliferation, migration and tube formation in vitro. Cysmethynil also promoted M1 anti-tumor macrophage homing in the pleural space in vivo, and inhibited tumor-induced polarization of macrophages towards a M2 phenotype in vitro. In addition, the inhibitor promoted adenocarcinoma cell apoptosis in vivo. Inhibition of small GTPase might thus represent a valuable strategy for pharmacotherapy of MPE.

Cisplatin, Oxaliplatin, and Kiteplatin Subcellular Effects Compared in a Plant Model

The immediate visual comparison of platinum chemotherapeutics’ effects in eukaryotic cells using accessible plant models of transgenic Arabidopsis thaliana is reported. The leading anticancer drug cisplatin, a third generation drug used for colon cancer, oxaliplatin and kiteplatin, promising Pt-based anticancer drugs effective against resistant lines, were administered to transgenic A. thaliana plants monitoring their effects on cells from different tissues. The transgenic plants’ cell cytoskeletons were labelled by the green fluorescent protein (GFP)-tagged microtubule-protein TUA6 (TUA6-GFP), while the vacuolar organization was evidenced by two soluble chimerical GFPs (GFPChi and AleuGFP) and one transmembrane GFP-tagged tonoplast intrinsic protein 1-1 (TIP1.1-GFP). The three drugs showed easily recognizable effects on plant subcellular organization, thereby providing evidence for a differentiated drug targeting. Genetically modified A. thaliana are confirmed as a possible rapid and low-cost screening tool for better understanding the mechanism of action of human anticancer drugs.

Super-resolution imaging for monitoring cytoskeleton dynamics

The cytoskeleton is a key cellular structure that is important in the control of cellular movement, structure, and sensing. To successfully image the individual cytoskeleton components, high resolution and super-resolution fluorescence imaging methods are needed. This review covers the three basic cytoskeletal elements and the relative benefits and drawbacks of fixed versus live cell imaging before moving on to recent studies using high resolution and super-resolution techniques. The techniques covered include the near-diffraction limited imaging methods of confocal microscopy and TIRF microscopy and the super-resolution fluorescence imaging methods of STORM, PALM, and STED.

Nano-mechanical Phenotype as a Promising Biomarker to Evaluate Cancer Development, Progression, and Anti-cancer Drug Efficacy

Since various bio-mechanical assays have been introduced for studying mechanical properties of biological samples, much progress has been made in cancer biology. It has been noted that enhanced mechanical deformability can be used as a marker for cancer diagnosis. The relation between mechanical compliances and the metastatic potential of cancer cells has been suggested to be a promising prognostic marker. Although it is yet to be conclusive about its clinical application due to the complexity in the tissue integrity, the nano-mechanical compliance of human cell samples has been evaluated by several groups as a promising marker in diagnosing cancer development and anticipating its progression. In this review, we address the mechanical properties of diverse cancer cells obtained by atomic force microscopy-based indentation experiments and reiterate prognostic relations between the nano-mechanical compliance and cancer progression. We also review the nano-mechanical responses of cancer cells to the anti-cancer drug treatment in order to interrogate a possible use of nano-mechanical compliance as a means to evaluate the effectiveness of anti-cancer drugs.

Mesenchymal stem cells maintain their defining stem cell characteristics after treatment with cisplatin

Mesenchymal stem cells (MSCs) aid the regeneration of tissues damaged by treatment with cisplatin. However, the effects of this cytotoxic drug on the stem cells have been largely unknown. Here we demonstrate that human bone marrow-derived MSCs are relatively resistant to cisplatin treatment and show resistance levels comparable to these of differentiated fibroblasts. Cisplatin did not affect cellular morphology, adhesion or induction of apoptosis in MSCs. The potential for differentiation was preserved after exposure to cisplatin, and established MSC surface markers were observed to be stably expressed irrespective of cisplatin treatment. Cytoskeletal rearrangements and high expression levels of individual heat shock proteins were detected in MSCs and may be partly responsible for the observed cisplatin resistance. The cisplatin-resistant phenotype of human MSCs supports the concept of further investigating these stem cells as a potential treatment option for cisplatin-induced tissue damage.

The impact of sphingosine kinase inhibitor-loaded nanoparticles on bioelectrical and biomechanical properties of cancer cells

Cancer progression and physiological changes within the cells are accompanied by alterations in the biophysical properties. Therefore, the cell biophysical properties can serve as promising markers for cancer detection and physiological activities. To aid in the investigation of the biophysical markers of cells, a microfluidic chip has been developed which consists of a constriction channel and embedded microelectrodes. Single-cell impedance magnitudes at four frequencies and entry and travel times are measured simultaneously during their transit through the constriction channel. This microchip provides a high-throughput, label-free, automated assay to identify biophysical signatures of malignant cells and monitor the therapeutic efficacy of drugs. Here, we monitored the dynamic cellular biophysical properties in response to sphingosine kinase inhibitors (SphKIs), and compared the effectiveness of drug delivery using poly lactic-co-glycolic acid (PLGA) nanoparticles (NPs) loaded with SphKIs versus conventional delivery. Cells treated with SphKIs showed significantly higher impedance magnitudes at all four frequencies. The bioelectrical parameters extracted using a model also revealed that the highly aggressive breast cells treated with SphKIs shifted electrically towards that of a less malignant phenotype; SphKI-treated cells exhibited an increase in cell-channel interface resistance and a significant decrease in specific membrane capacitance. Furthermore, SphKI-treated cells became slightly more deformable as measured by a decrease in their channel entry and travel times. We observed no significant difference in the bioelectrical changes produced by SphKI delivered conventionally or with NPs. However, NPs-packaged delivery of SphKI decreased the cell deformability. In summary, this study showed that while the bioelectrical properties of the cells were dominantly affected by SphKIs, the biomechanical properties were mainly changed by the NPs.