Integrin β3 links therapy resistance and cancer stem cell properties

ITGB3 promotes cisplatin resistance in osteosarcoma tumors

OBJECTIVE

Osteosarcoma is the most malignant and common primary bone tumor with a high rate of recurrence that mainly occurs in children and young adults. Therefore, it is vital to facilitate the development of novel effective therapeutic means and improve the overall prognosis of osteosarcoma patients via a deeper understanding of the mechanisms of chemoresistance in osteosarcoma progression.

METHODS

In this research, the relationship between ITGB3 and the clinical characteristics of patients was detected through analysis of publicly available clinical datasets. The expression of ITGB3 was analysis in collected human osteosarcoma tissues. In addition, the potential functions of ITGB3 in the cisplatin resistance of osteosarcoma cells were investigated in vitro and in tumor xenotransplantation. Finally, the molecular mechanism of ITGB3 in the progression and recurrence of osteosarcoma were explored via transcriptome analysis.

RESULTS

ITGB3 was identified as a potential regulator of tumorigenicity and cisplatin resistance in relapsed osteosarcoma. Furthermore, the decreased osteosarcoma cell proliferation and migration ability in ITGB3 knockout osteosarcoma cells were related to increased apoptosis and slowing cell cycle progression. In addition, ITGB3 had a positive correlation with cisplatin resistance in cells and tumor xenografts in mice. Accordingly, ITGB3 performed the functions of proliferation and cisplatin resistance in osteosarcoma through the MAPK and VEGF signaling pathways.

CONCLUSION

Our results will contribute to a better understanding of the function and mechanism of ITGB3 in osteosarcoma cisplatin resistance and provide a novel therapeutic target to decrease cisplatin resistance and tumor recurrence in osteosarcoma patients.

Molecular Modeling Insights into the Structure and Behavior of Integrins: A Review

Integrins are heterodimeric glycoproteins crucial to the physiology and pathology of many biological functions. As adhesion molecules, they mediate immune cell trafficking, migration, and immunological synapse formation during inflammation and cancer. The recognition of the vital roles of integrins in various diseases revealed their therapeutic potential. Despite the great effort in the last thirty years, up to now, only seven integrin-based drugs have entered the market. Recent progress in deciphering integrin functions, signaling, and interactions with ligands, along with advancement in rational drug design strategies, provide an opportunity to exploit their therapeutic potential and discover novel agents. This review will discuss the molecular modeling methods used in determining integrins' dynamic properties and in providing information toward understanding their properties and function at the atomic level. Then, we will survey the relevant contributions and the current understanding of integrin structure, activation, the binding of essential ligands, and the role of molecular modeling methods in the rational design of antagonists. We will emphasize the role played by molecular modeling methods in progress in these areas and the designing of integrin antagonists.

Unique hypoxia-tolerant subpopulations of adipose-derived stem cells: ITGB3+ cells

BACKGROUND

We found by accident that stem cells could still be isolated from adipose tissue stored for 14 days in sealed tubes, which was distinct from previous protocols. The morphology of these hypoxia-tolerant stem cells also differs from that of conventional adipose-derived stem cells (ADSCs). In this study, we aim to define the newly found subsets.

MATERIALS AND METHODS

Stem cells were isolated from adipose tissue that was aspirated immediately or stored for 14 days. The stem cells were then harvested for flowcytometric analysis and differentiation potentials. The expression of hypoxia-inducible factor 1 alpha (HIF-1α) was assayed to confirm the hypoxia-tolerant ability. RNA sequencing (RNA-seq) was performed to find the common signatures of the hypoxia-tolerant cells. The result of bioinformatics was tested by quantitative real-time reverse transcription-polymerase chain reaction (qPCR) and western blotting.

RESULTS

Certain subsets of ADSCs can be isolated from adipose tissue stored for 14 days. These survived cells were positive for CD90, CD105, and CD73 and showed multilineage differentiation potentials. The hypoxic condition was evidenced by up-regulation of HIF-1α for 2.0-fold changes (p < 0.05). The hypoxia-tolerant stem cells were distinct from multilineage-differentiating stress-enduring (Muse) cells, previously found stress-enduring stromal cells. RNA-seq suggested that integrin beta 3 (ITGB3) was highly expressed in hypoxia-tolerant subpopulations. The result was further confirmed at transcription and translation levels by qPCR and western blotting (mRNA: 2.9 ± 0.4, p < 0.05; protein: 1.5 ± 0.2, p < 0.05; respectively). The conventional ADSCs are positive for ITGB3, which implies that ITGB3+ cells are subpopulations of heterogeneous ADSCs.

CONCLUSIONS

Our study reveals the ITGB3⁺ subsets with potent hypoxia tolerance, which has significant implications for improving fat retention rates and curing obesity-related diseases.

NUMB suppression by miR-9-5P enhances CD44+ prostate cancer stem cell growth and metastasis

Experimental and clinical studies over the past two decades have provided overwhelming evidence that human cancers, including prostate cancer (PCa), harbor cancer stem cells (CSCs) that sustain tumor growth, drive tumor progression and mediate therapy resistance and tumor relapse. Recent studies have also implicated NUMB as a PCa suppressor and an inhibitor of PCa stem cells (PCSCs); however, exactly how NUMB functions in these contexts remains unclear. Here, by employing bioinformatics analysis and luciferase assays and by conducting rescue experiments, we first show that NUMB is directly targeted by microRNA-9-5p (miR-9-5p), an oncogenic miR associated with poor prognosis in many malignancies. We further show that miR-9-5p levels are inversely correlated with NUMB expression in CD44+ PCSCs. miR-9-5p reduced NUMB expression and inhibited numerous PCSC properties including proliferation, migration, invasion as well as self-renewal. Strikingly, overexpression of NUMB in CD44+ PCSCs overcame all of the above PCSC properties enforced by miR-9-5p. Taken together, our results suggest that inhibiting the expression of the oncomiR miR-9-5p and overexpressing NUMB may represent novel therapeutic strategies to target PCSCs and PCa metastasis.

Hydrogel Scaffolds to Deliver Cell Therapies for Wound Healing

Cutaneous wounds are a growing global health burden as a result of an aging population coupled with increasing incidence of diabetes, obesity, and cancer. Cell-based approaches have been used to treat wounds due to their secretory, immunomodulatory, and regenerative effects, and recent studies have highlighted that delivery of stem cells may provide the most benefits. Delivering these cells to wounds with direct injection has been associated with low viability, transient retention, and overall poor efficacy. The use of bioactive scaffolds provides a promising method to improve cell therapy delivery. Specifically, hydrogels provide a physiologic microenvironment for transplanted cells, including mechanical support and protection from native immune cells, and cell-hydrogel interactions may be tailored based on specific tissue properties. In this review, we describe the current and future directions of various cell therapies and usage of hydrogels to deliver these cells for wound healing applications.

Bone Marrow Mesenchymal Stem Cells Promote the Stemness of Hypopharyngeal Cancer Cells

A study was to investigate the regulation of bone marrow mesenchymal stem cells (BMSCs) on the stemness of hypopharyngeal cancer cells (FaDu cells). Green fluorescent protein-labeled FaDu cells were cocultured with BMSCs and then were isolated. In vitro experiments, including cell cycle and apoptosis analyses and clonogenic and sphere formation assays, were conducted using the cocultured FaDu cells to determine the stemness of FaDu cells. The tumor formation assay was performed through subcutaneous injection of FaDu cells into nude mice to determine the tumorigenic ability of FaDu cells after coculture. Immunohistochemical analysis of CD44 and ALDH1 was performed on the tumor tissue. After coculturing with human BMSCs, the ratio of FaDu cells at G2 phase was increased, while the ratios at S and G1 phases were decreased. In addition, coculture reduced apoptosis, but increased the clonogenic ability and sphere formation efficiency of FaDu cells. Finally, coculturing FaDu cells induced more robust and faster tumor formation as well as increased expression levels of CD44 and ALDH1 in tumor tissue. BMSCs promote the stemness of hypopharyngeal cancer cells.

Ligustrazine recovers thiram-induced tibial dyschondroplasia in chickens: Involvement of new molecules modulating integrin beta 3

Tetramethyl thiuram disulfide (thiram) is a dithiocarbamate, which is extensively used in agriculture as pesticide and fungicide for treating grains intended for seed purposes and also for storing food grains. One of the most evident and detrimental effect produced by thiram is tibial dyschondroplasia (TD) in many avian species, by feeding diets containing thiram, a growth plate cartilage disease. TD is characterized by the lack of blood vessels and impaired vascular invasion of the hypertrophic chondrocyte resulting in the massive cell death. This study investigated the effects of ligustrazine on the treatment and control of thiram induced-TD. A total of 210 chicks were divided into three equal groups (n = 70): control group (received standard diet), TD group (feed on thiram containing diet from day 3-7), and ligustrazine group (feed on thiram containing diet from day 3-7 and after that ligustrazine @ 30 mg/kg from day 8 to day 18). During the experiment, the lameness, production parameters, tibia bone indicators, pathological index changes and integrin beta 3 (ITGB3) expressions were examined. The results reveal that ligustrazine plays an important role in improving angiogenesis and decreasing chondrocytes damage in TD chicks via a new molecule modulating ITGB3. So, the administration of ligustrazine can be an important way to cope with the losses and costs associated with TD in commercial poultry farming and animal welfare issue due to environmental contamination of thiram.

Implementation of a Precision Pathology Program Focused on Oncology-Based Prognostic and Predictive Outcomes

Personalized or precision medicine as a diagnostic and therapeutic paradigm was introduced some 10-15 years ago, with the advent of biomarker discovery as a mechanism for identifying prognostic and predictive attributes associated with treatment indication and outcome. While the concept is not new, the successful development and implementation of novel 'companion diagnostics', especially in oncology, continues to represent a significant challenge and is currently at the forefront of smart trial design and therapeutic choice. The ability to determine patient selection for a specific therapy has broad implications including better chances for a positive outcome, limited exposure to potentially toxic drugs and improved health economics. Importantly, a significant step in this paradigm is the role of predictive pathology or the accurate assessment of morphology at the microscopic level. In breast cancer, this has been most useful where histologic attributes such as the classification of tubular and cribriform carcinoma dictates surgery while neoadjuvant studies suggest that patients with lobular carcinoma are not likely to benefit from chemotherapy. The next level of 'personalized pathology' at the tissue-cellular level is the use of 'protein biomarker panels' to classify the disease process and ultimately drive tumor characterization and treatment. The following review article will focus on the evolution of predictive pathology from a subjective, 'opinion-based' approach to a quantitative science. In addition, we will discuss the individual components of the precise pathology platform including advanced image analysis, biomarker quantitation with mathematical modeling and the integration with fluid-based (i.e. blood, urine) analytics as drivers of next generation precise patient phenotyping.

Molecular chess? Hallmarks of anti-cancer drug resistance

Background

The development of resistance is a problem shared by both classical chemotherapy and targeted therapy. Patients may respond well at first, but relapse is inevitable for many cancer patients, despite many improvements in drugs and their use over the last 40 years.

Review

Resistance to anti-cancer drugs can be acquired by several mechanisms within neoplastic cells, defined as (1) alteration of drug targets, (2) expression of drug pumps, (3) expression of detoxification mechanisms, (4) reduced susceptibility to apoptosis, (5) increased ability to repair DNA damage, and (6) altered proliferation. It is clear, however, that changes in stroma and tumour microenvironment, and local immunity can also contribute to the development of resistance. Cancer cells can and do use several of these mechanisms at one time, and there is considerable heterogeneity between tumours, necessitating an individualised approach to cancer treatment. As tumours are heterogeneous, positive selection of a drug-resistant population could help drive resistance, although acquired resistance cannot simply be viewed as overgrowth of a resistant cancer cell population. The development of such resistance mechanisms can be predicted from pre-existing genomic and proteomic profiles, and there are increasingly sophisticated methods to measure and then tackle these mechanisms in patients.

Conclusion

The oncologist is now required to be at least one step ahead of the cancer, a process that can be likened to ‘molecular chess’. Thus, as well as an increasing role for predictive biomarkers to clinically stratify patients, it is becoming clear that personalised strategies are required to obtain best results.

Microfluidic single-cell transcriptional analysis rationally identifies novel surface marker profiles to enhance cell-based therapies

Current progenitor cell therapies have only modest efficacy, which has limited their clinical adoption. This may be the result of a cellular heterogeneity that decreases the number of functional progenitors delivered to diseased tissue, and prevents correction of underlying pathologic cell population disruptions. Here, we develop a high-resolution method of identifying phenotypically distinct progenitor cell subpopulations via single-cell transcriptional analysis and advanced bioinformatics. When combined with high-throughput cell surface marker screening, this approach facilitates the rational selection of surface markers for prospective isolation of cell subpopulations with desired transcriptional profiles. We establish the usefulness of this platform in costly and highly morbid diabetic wounds by identifying a subpopulation of progenitor cells that is dysfunctional in the diabetic state, and normalizes diabetic wound healing rates following allogeneic application. We believe this work presents a logical framework for the development of targeted cell therapies that can be customized to any clinical application.

Unrecognized progenitor cell perturbations underlying a disease state may limit the efficacy of cell therapies. Here, the authors use high-throughput, single-cell transcriptional analysis to identify disease-specific cellular alterations and prospectively isolate restorative cell subpopulations.

Galectin-1 induces hepatocellular carcinoma EMT and sorafenib resistance by activating FAK/PI3K/AKT signaling

Galectin-1 (Gal-1) is involved in several pathological activities associated with tumor progression and chemoresistance, however, the role and molecular mechanism of Gal-1 activity in hepatocellular carcinoma (HCC) epithelial–mesenchymal transition (EMT) and sorafenib resistance remain enigmatic. In the present study, forced Gal-1 expression promoted HCC progression and sorafenib resistance. Gal-1 elevated αvβ3-integrin expression, leading to AKT activation. Moreover, Gal-1 overexpression induced HCC cell EMT via PI3K/AKT cascade activation. Clinically, our data revealed that Gal-1 overexpression is correlated with poor HCC survival outcomes and sorafenib response. These data suggest that Gal-1 may be a potential therapeutic target for HCC and a biomarker for predicting response to sorafenib treatment.

Multifunctional Tandem Peptide Modified Paclitaxel-Loaded Liposomes for the Treatment of Vasculogenic Mimicry and Cancer Stem Cells in Malignant Glioma

The chemotherapy of aggressive glioma is usually accompanied by a poor prognosis because of the formation of vasculogenic mimicry (VM) and brain cancer stem cells (BCSCs). VM provided a transporting pathway for nutrients and blood to the extravascular regions of the tumor, and BCSCs were always related to drug resistance and the relapse of glioma. Thus, it is important to evaluate the inhibition effect of antiglioma drug delivery systems on both VM and BCSCs. In this study, paclitaxel-loaded liposomes modified with a multifunctional tandem peptide R8-c(RGD) (R8-c(RGD)-Lip) were used for the treatment of glioma. An in vitro cellular uptake study proved the strongest targeting ability to be that of R8-c(RGD)-Lip to glioma stem cells. Drug loaded R8-c(RGD)-Lip exhibited an efficient antiproliferation effect on BCSCs and could induce the destruction of VM channels in vitro. The following pharmacodynamics study demonstrated that R8-c(RGD)-modified drug-loaded liposomes achieved both anti-VM and anti-BCSC effects in vivo. Finally, no significant cytotoxicity of the blood system or major organs of the drug-loaded liposomes was observed under treatment dosage in the safety evaluation. In conclusion, all of the results proved that R8-c(RGD)-Lip was a safe and efficient antiglioma drug delivery system.

Nsc23925 prevents the development of paclitaxel resistance by inhibiting the introduction of P-glycoprotein and enhancing apoptosis

Strategies to prevent the emergence of drug resistance will increase the effectiveness of chemotherapy treatment and prolong survival of women with ovarian cancer. The aim of our study is to determine the effects of NSC23925 on preventing the development of paclitaxel resistance in ovarian cancer both in cultured cells in vitro and in mouse xenograft models in vivo, and to further elucidate these underlying mechanisms. We first developed a paclitaxel-resistant ovarian cancer cell line, and demonstrated that NSC23925 could prevent the introduction of paclitaxel resistance by specifically inhibiting the overexpression of P-glycoprotein (Pgp) in vitro. The paclitaxel-resistant ovarian cancer cells were then established in a mouse model by continuous paclitaxel treatment in combination with or without NSC23925 administration in the mice. The majority of mice continuously treated with paclitaxel alone eventually developed paclitaxel resistance with overexpression of Pgp and antiapoptotic proteins, whereas mice remained sensitivity to paclitaxel and displayed lower expression levels of Pgp and antiapoptotic proteins after administered continuously with combination of paclitaxel-NSC23925. Paclitaxel-NSC23925-treated mice experienced significantly longer overall survival time than paclitaxel-treated mice. Furthermore, the combination of paclitaxel and NSC23925 therapy did not induce obvious toxicity as measured by mice body weight changes, blood cell counts and histology of internal organs. Collectively, our observations provide evidence that NSC23925 in combination with paclitaxel may prevent the onset of Pgp or antiapoptotic-mediated paclitaxel resistance, and improve the long-term clinical outcome in patients with ovarian cancer.

Synchronized cell attachment triggered by photo-activatable adhesive ligands allows QCM-based detection of early integrin binding

The Quartz Crystal Microbalance with dissipation (QCM-D) technique was applied to monitor and quantify integrin-RGD recognition during the early stages of cell adhesion. Using QCM-D crystals modified with a photo-activatable RGD peptide, the time point of presentation of adhesive ligand at the surface of the QCM-D crystal could be accurately controlled. This allowed temporal resolution of early integrin-RGD binding and the subsequent cell spreading process, and their separate detection by QCM-D. The specificity of the integrin-RGD binding event was corroborated by performing the experiments in the presence of soluble cyclicRGD as a competitor, and cytochalasin D as inhibitor of cell spreading. Larger frequency change in the QCM-D signal was observed for cells with larger spread area, and for cells overexpressing integrin α_vβ₃ upon stable transfection. This strategy enables quantification of integrin activity which, in turn, may allow discrimination among different cell types displaying distinct integrin subtypes and expression levels thereof. On the basis of these findings, we believe the strategy can be extended to other photoactivatable ligands to characterize cell membrane receptors activity, a relevant issue for cancer diagnosis (and prognosis) as other several pathologies.

Translational horizons in the tumor microenvironment: harnessing breakthroughs and targeting cures

Chemotherapy and targeted therapy have opened new avenues in clinical oncology. However, there is a lack of response in a substantial percentage of cancer patients and diseases frequently relapse in those who even initially respond. Resistance is, at present, the major barrier to conquering cancer, the most lethal age-related pathology. Identification of mechanisms underlying resistance and development of effective strategies to circumvent treatment pitfalls thereby improving clinical outcomes remain overarching tasks for scientists and clinicians. Growing bodies of data indicate that stromal cells within the genetically stable but metabolically dynamic tumor microenvironment confer acquired resistance against anticancer therapies. Further, treatment itself activates the microenvironment by damaging a large population of benign cells, which can drastically exacerbate disease conditions in a cell nonautonomous manner, and such off-target effects should be well taken into account when establishing future therapeutic rationale. In this review, we highlight relevant biological mechanisms through which the tumor microenvironment drives development of resistance. We discuss some unsolved issues related to the preclinical and clinical trial paradigms that need to be carefully devised, and provide implications for personalized medicine. In the long run, an insightful and accurate understanding of the intricate signaling networks of the tumor microenvironment in pathological settings will guide the design of new clinical interventions particularly combinatorial therapies, and it might help overcome, or at least prevent, the onset of acquired resistance.

α integrin targeting for radiosensitization of three-dimensionally grown human head and neck squamous cell carcinoma cells

Integrin cell adhesion molecules play a crucial role in tumor cell resistance to radio- and chemotherapy and are therefore considered attractive targets for cancer therapy. Here, we assessed the role of β1 integrin-interacting α integrin subunits in more physiological three-dimensional extracellular matrix grown head and neck squamous cell carcinoma (HNSCC) cell cultures for evaluating cytotoxic and radiosensitizing potential. α2, α3, α5 and α6 integrins, which are overexpressed in HNSCC according to Oncomine database analysis, were coprecipitated with β1 integrin. More potently than α2, α5 or α6 integrin inhibition, siRNA-based α3 integrin targeting resulted in reduced clonogenic cell survival, induced apoptosis and enhanced radiosensitivity. These events were associated with diminished phosphorylation of Akt, Cortactin and Paxillin. Cell line-dependently, simultaneous α3 and β1 integrin inhibition led to higher cytotoxicity and radiosensitization than α3 integrin blocking alone. Stable overexpression of wild-type and constitutively active forms of the integrin signaling mediator focal adhesion kinase (FAK) revealed FAK as a key determinant of α3 integrin depletion-mediated radiosensitization. Our findings show that α3 integrin is essentially involved in HNSCC cell radioresistance and critical for a modified cellular radiosensitivity along with β1 integrins.

Overcoming tumor heterogeneity in the molecular diagnosis of urological cancers

Our understanding of tumor heterogeneity and impact on treatment response is still in its infancy, presenting significant challenges to the molecular pathologist, treating physician and ultimately for the patient. Given that tumor recurrence due to treatment resistance is the most common cause of cancer death, there remains a critical unmet need to change the current paradigm. The mechanisms which underlie tumor heterogeneity can be broadly divided into genomic instability and non-mutational processes, including stochastic variations in cellular responses, modulation by tumor microenvironment and or phenotypic/ functional plasticity relating to cancer stem cells. We believe that these biological mechanisms are not mutually exclusive and emphasize the need for more suitable methodologies to exploit the spatiotemporal patterns of intratumoral heterogeneity using novel approaches such as quantitative tissue-based biomarker assessment and systemic fluid analytics. Generating a comprehensive patient-centric phenotypic disease profile should generate a 'codex' which can be employed to change the current treatment decision process.