Depletion of Survivin suppresses docetaxel-induced apoptosis in HeLa cells by facilitating mitotic slippage

Docetaxel-Induced Cell Death Is Regulated by a Fatty Acid-Binding Protein 12-Slug-Survivin Pathway in Prostate Cancer Cells

Chemotherapy is an important treatment option for advanced prostate cancer, especially for metastatic prostate cancer (PCa). Resistance to first-line chemotherapeutic drugs such as docetaxel often accompanies prostate cancer progression. Attempts to overcome resistance to docetaxel by combining docetaxel with other biological agents have been mostly unsuccessful. A better understanding of the mechanisms underlying docetaxel resistance may provide new avenues for the treatment of advanced PCa. We have previously found that the fatty acid-binding protein 12 (FABP12)-PPARγ pathway modulates lipid-related bioenergetics and PCa metastatic transformation through induction of Slug, a master driver of epithelial-to-mesenchymal transition (EMT). Here, we report that the FABP12-Slug axis also underlies chemoresistance in PCa cells. Cell sensitivity to docetaxel is markedly suppressed in FABP12-expressing cells, along with induction of Survivin, a typical apoptosis inhibitor, and inhibition of cleaved PARP, a hallmark of programmed cell death. Importantly, Slug depletion down-regulates Survivin and restores cell sensitivity to docetaxel in FABP12-expressing cells. Finally, we also show that high levels of Survivin are associated with poor prognosis in PCa patients, with FABP12 status determining its prognostic significance. Our research identifies a FABP12-Slug-Survivin pathway driving docetaxel resistance in PCa cells, suggesting that targeting FABP12 may be a precision approach to improve chemodrug efficacy and curb metastatic progression in PCa.

Preparation, Optimization, and In-Vitro Evaluation of Brusatol- and Docetaxel-Loaded Nanoparticles for the Treatment of Prostate Cancer

Challenges to docetaxel use in prostate cancer treatment include several resistance mechanisms as well as toxicity. To overcome these challenges and to improve the therapeutic efficacy in heterogeneous prostate cancer, the use of multiple agents that can destroy different subpopulations of the tumor is required. Brusatol, a multitarget inhibitor, has been shown to exhibit potent anticancer activity and play an important role in drug response and chemoresistance. Thus, the combination of brusatol and docetaxel in a nanoparticle platform for the treatment of prostate cancer is expected to produce synergistic effects. In this study, we reported the development of polymeric nanoparticles for the delivery of brusatol and docetaxel in the treatment of prostate cancer. The one-factor-at-a-time method was used to screen for formulation and process variables that impacted particle size. Subsequently, factors that had modifiable effects on particle size were evaluated using a 24 full factorial statistical experimental design followed by the optimization of drug loading. The optimization of blank nanoparticles gave a formulation with a mean size of 169.1 nm ± 4.8 nm, in agreement with the predicted size of 168.333 nm. Transmission electron microscopy showed smooth spherical nanoparticles. The drug release profile showed that the encapsulated drugs were released over 24 h. Combination index data showed a synergistic interaction between the drugs. Cell cycle analysis and the evaluation of caspase activity showed differences in PC-3 and LNCaP prostate cancer cell responses to the agents. Additionally, immunoblots showed differences in survivin expression in LNCaP cells after treatment with the different agents and formulations for 24 h and 72 h. Therefore, the nanoparticles are potentially suitable for the treatment of advanced prostate cancer.

PEDOT:PSS-Based Bioelectrodes for Multifunctional Drug Release and Electric Cell-Substrate Impedance Sensing

Electric cell-substrate impedance sensing (ECIS) is an innovative approach for the label-free and real-time detection of cell morphology, growth, and apoptosis, thereby playing an essential role as both a viable alternative and valuable complement to conventional biochemical/pharmaceutical analysis in the field of diagnostics. Constant improvements are naturally sought to further improve the effective range and reliability of this technology. In this study, we developed poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) conducting polymer (CP)-based bioelectrodes integrated into homemade ECIS cell-culture chamber slides for the simultaneous drug release and real-time biosensing of cancer cell viability under drug treatment. The CP comprised tailored PEDOT:PSS, poly(ethylene oxide) (PEO), and (3-glycidyloxypropyl)trimethoxysilane (GOPS) capable of encapsulating antitumor chemotherapeutic agents such as doxorubicin (DOX), docetaxel (DTX), and a DOX/DTX combination. This device can reliably monitor impedance signal changes correlated with cell viability on chips generated by cell adhesion onto a predetermined CP-based working electrode while simultaneously exhibiting excellent properties for both drug encapsulation and on-demand release from another CP-based counter electrode under electrical stimulation (ES) operation. Cyclic voltammetry curves and surface profile data of different CP-based coatings (without or with drugs) were used to analyze the changes in charge capacity and thickness, respectively, thereby further revealing the correlation between their drug-releasing performance under ES operation (determined using ultraviolet-visible (UV-vis) spectroscopy). Finally, antitumor drug screening tests (DOX, DTX, and DOX/DTX combination) were performed on MCF-7 and HeLa cells using our developed CP-based ECIS chip system to monitor the impedance signal changes and their related cell viability results.

The prognostic gene CRABP2 affects drug sensitivity by regulating docetaxel-induced apoptosis in breast invasive carcinoma: A pan-cancer analysis

Cellular retinoic acid-binding protein 2 (CRABP2), a specific transporter of retinoic acid, has been shown to have an important biological role in human cancers. However, due to the substantial variability among different tumors, the role of CRABP2 remains uncertain and has not yet been subjected to systematic analysis. Utilizing The Cancer Genome Atlas (TCGA), Genotype-Tissue Expression (GTEx), Clinical Proteomic Tumor Analysis Consortium (CPTAC), Human Protein Atlas (HPA), Gene Expression Profiling Interactive Analysis 2 (GEPIA2), Kaplan-Meier Plotter, Biomarker Exploration of Solid Tumors (BEST), Cancer Cell Line Encyclopedia (CCLE), Receiver Operating Characteristic plotter (ROC plotter), and other online public tools, expression levels of CRABP2 in breast invasive carcinoma (BRCA), lung adenocarcinoma (LUAD), and ovarian serous cystadenocarcinoma (OV) were found to be significantly greater than those in adjacent normal tissues, suggesting a correlation to poor prognosis. Among the three, CRABP2 expression in BRCA was most closely associated with clinical prognosis. In a study of docetaxel-treated BRCA patients, CRABP2 expression was significantly higher in the drug-resistant group. Colony formation and flow cytometry analysis were used to further investigate the relationship between CRABP2 and docetaxel sensitivity in BRCA cells MDA-MB-231and BT549. The knockdown of CRABP2 expression significantly reduced cell growth and increased sensitivity to the chemotherapeutic agent docetaxel in BRCA cells. Furthermore, CRABP2 knockdown augmented docetaxel-induced apoptosis. Molecular docking using SwissDock tool revealed that CRABP2 had a greater binding affinity to docetaxel than docetaxel-targeted proteins. This research provides an insight into the expression and prognostic potential of CRABP2 in cancers and suggests that CRABP2 may control docetaxel sensitivity in BRCA cells through apoptosis, warranting further investigation.

The second half of mitosis and its implications in cancer biology

The nucleus undergoes dramatic structural and functional changes during cell division. With the entry into mitosis, in human cells the nuclear envelope breaks down, chromosomes rearrange into rod-like structures which are collected and segregated by the spindle apparatus. While these processes in the first half of mitosis have been intensively studied, much less is known about the second half of mitosis, when a functional nucleus reforms in each of the emerging cells. Here we review our current understanding of mitotic exit and nuclear reformation with spotlights on the links to cancer biology.

Therapy-Induced Tumor Cell Senescence: Mechanisms and Circumvention

Plasticity of tumor cells (multitude of molecular regulation pathways) allows them to evade cytocidal effects of chemo- and/or radiation therapy. Metabolic adaptation of the surviving cells is based on transcriptional reprogramming. Similarly to the process of natural cell aging, specific features of the survived tumor cells comprise the therapy-induced senescence phenotype. Tumor cells with this phenotype differ from the parental cells since they become less responsive to drugs and form aggressive progeny. Importance of the problem is explained by the general biological significance of transcriptional reprogramming as a mechanism of adaptation to stress, and by the emerging potential of its pharmacological targeting. In this review we analyze the mechanisms of regulation of the therapy-induced tumor cell senescence, as well as new drug combinations aimed to prevent this clinically unfavorable phenomenon.

Exploring the Expression of Survivin on Neoadjuvant Chemotherapy in Invasive Breast Carcinoma

Background:   Biomarkers are required to monitor the response to neoadjuvant chemotherapy (NC) in patients with invasive breast cancer (IBC). The purpose of this study is to determine the function of Survivin in the administration of NC, both taxane- and non-taxane-based, to patients with IBC. Methods: Thirty-one samples were categorized according to the NC's administrative status (before or after) and the type of NC used (taxane- or non-taxane-based). Age, tumor grade, receptor status (ER, PR, HER2, Ki-67), and survivin expression were evaluated. Survivin expressions were evaluated by IHC staining and categorized according median H-score cut-offs, while other data were collected from archives. Data was gathered and analyzed using generalized linear model.  Results:  Survivin expression decreased following NC administration, although not significantly (p=0.285). The taxane group had lower survivin expression. Statistically, this was not significant (p=0.329). The non-taxane group had the same outcome (p=0.792). The decline in survivin expression was greater in the taxane group than in the non-taxane group, although it was not statistically significant (p=0.369). Conclusion: Although the changes in survivin expression were not statistically significant, when clinical and laboratory data are analyzed, survivin expression has the potential to be a predictive biomarker of NC response as well as clinical outcome in IBC.

Development of Multi-Scale X-ray Fluorescence Tomography for Examination of Nanocomposite-Treated Biological Samples

Simple Summary

Metal-oxide nanomaterials enter cancer and normal cells even when not specifically targeted, and often interact with specific cellular structures and biological molecules solely due to their innate physical-chemical properties. This raises concerns for the use of nanoparticles, which can be alleviated only with rigorous studies of nanoparticle–cell interactions, studies independent of post-interaction labeling of nanomaterials. X-ray fluorescence microscopy is an imaging technique that quantifies and maps all chemical elements from the periodic table solely based on their native fluorescence excited by the incoming X-ray. We used two different instruments to interrogate the same sample in 3D at two different resolutions and determine heterogeneity of cell-to-cell interactions with nanomaterials, as well as subcellular nanoparticle distribution. This is the first example of multi-scale 3D X-ray fluorescence imaging. This work begins a new era of study on how nanoparticle-based therapies can be developed to be more predictable and safer for use.

Abstract

Research in cancer nanotechnology is entering its third decade, and the need to study interactions between nanomaterials and cells remains urgent. Heterogeneity of nanoparticle uptake by different cells and subcellular compartments represent the greatest obstacles to a full understanding of the entire spectrum of nanomaterials’ effects. In this work, we used flow cytometry to evaluate changes in cell cycle associated with non-targeted nanocomposite uptake by individual cells and cell populations. Analogous single cell and cell population changes in nanocomposite uptake were explored by X-ray fluorescence microscopy (XFM). Very few nanoparticles are visible by optical imaging without labeling, but labeling increases nanoparticle complexity and the risk of modified cellular uptake. XFM can be used to evaluate heterogeneity of nanocomposite uptake by directly imaging the metal atoms present in the metal-oxide nanocomposites under investigation. While XFM mapping has been performed iteratively in 2D with the same sample at different resolutions, this study is the first example of serial tomographic imaging at two different resolutions. A cluster of cells exposed to non-targeted nanocomposites was imaged with a micron-sized beam in 3D. Next, the sample was sectioned for immunohistochemistry as well as a high resolution “zoomed in” X-ray fluorescence (XRF) tomography with 80 nm beam spot size. Multiscale XRF tomography will revolutionize our ability to explore cell-to-cell differences in nanomaterial uptake.

Platinum drugs and taxanes: can we overcome resistance?

Cancer therapy is aimed at the elimination of tumor cells and acts via the cessation of cell proliferation and induction of cell death. Many research publications discussing the mechanisms of anticancer drugs use the terms "cell death" and "apoptosis" interchangeably, given that apoptotic pathways are the most common components of the action of targeted and cytotoxic compounds. However, there is sound evidence suggesting that other mechanisms of drug-induced cell death, such as necroptosis, ferroptosis, autophagy, etc. may significantly contribute to the fate of cancer cells. Molecular cross-talks between apoptotic and nonapoptotic death pathways underlie the successes and the failures of therapeutic interventions. Here we discuss the nuances of the antitumor action of two groups of the widely used anticancer drugs, i.e., platinum salts and taxane derivatives. The available data suggest that intelligent interference with the choice of cell death pathways may open novel opportunities for cancer treatment.