Enhancement of Cytotoxicity and Inhibition of Angiogenesis in Oral Cancer Stem Cells by a Hybrid Nanoparticle of Bioactive Quinacrine and Silver: Implication of Base Excision Repair Cascade

The role of green synthesis metal and metal oxide nanoparticles in oral cancer therapy: a review

There are 275,000 new cases of oral cancer (OC) per year, making it the sixth most common cancer in the world. Severe adverse effects, including loss of function, deformity, and systemic toxicity, are familiar with traditional therapies such as radiation, chemotherapy, and surgery; due to their unique properties, nanoparticles (NPs) have emerged as a superior alternative over chemo/radiotherapy and surgery due to their targeting capability, bioavailability, compatibility, and high solubility. Due to their unique properties, metallic NPs have garnered significant attention in OC control. In addition to the fact that metal NPs may be harmful to human cells, the reactive chemicals used to make them pose the same risk, which limits their use in medicine. Green synthesis (GS) is a novel strategy that uses biological materials like yeast, bacteria, fungi, and plant extracts. Compared to more traditional chemical synthesis processes, these are more environmentally benign and manageable for living organisms. This article summarises the GS of NPs made of metals and metal oxides and their anticancer effects on OC. The method's potential benefits and drawbacks in advancing metallic NPs' GS and shaping OC therapy's future were also discussed.

Theranostic implications of Nectin-4 oncoprotein in gynecologic cancers: A review

INTRODUCTION

Gynecologic cancers, in order of prevalence, include uterine, ovarian, cervical, vaginal, and vulvar cancers. In 2024, there will be more than 116,000 new cases of gynecologic cancers and 33,800 disease-related deaths. Therefore, a concerted effort has been made to better understand the underlying pathophysiological processes and identify novel theranostic approaches.

PURPOSE

Comprehensively examine the current peer-reviewed literature surrounding Nectin-4 and its implication in the identification and treatment of gynecologic cancers.

METHODS

PubMed and Google search with relevant keywords for articles published in the last 15 years.

RESULTS

Nectin-4 as a cell adhesion molecule (CAM) promotes cell growth through intra-tumoral angiogenesis, strengthens cell-cell bonds, and creates a tight spheroid structure, which is more chemotherapy resistant. In high-grade serous ovarian cancer (HGSOC), Nectin-4 is strongly associated with the presence of peritoneal metastases and worse prognoses. When compared to CA-125, a common tumor marker for ovarian cancer, Nectin-4 showed higher specificity and sensitivity for predictive value of tumorigenesis. Regarding cervical cancer, inhibition of Nectin-4 by nanoformulated Quinacrine inhibits both cancer stem cell proliferation and DNA damage. Nectin-4 as a tumor marker can discriminate endometrial cancer from healthy adjacent tissue with a specificity of 95.4 % and sensitivity of 82.81 %. Lastly, there is scarce evidence of Nectin-4 and fallopian tube, vaginal, or vulvar cancer but given ovarian cancer cells may originate from the fallopian tube, there is plausibility of using Nectin-4 to detect fallopian and/or ovarian cancer earlier.

CONCLUSION

Overall, Nectin-4 as a promoter of cancer cell growth and metastasis supports the emphasis in current peer-reviewed literature as an effective theranostic biomarker.

Current Review on Nanophytomedicines in the Treatment of Oral Cancer: Recent Trends and Treatment Prospects

Cancer is one of the major life-threatening diseases in the world and oral cancer is the 8th most common type of deadly cancers in Asian countries. Despite many causes, tobacco is the main causative agent as 90% of oral cancer cases were due to daily consumption of tobacco and its products. The major drawback of the conventional therapies for oral cancer including chemotherapy, surgery and radiotherapy or combination of these is the dose limiting toxicity. Developments in technology and research led to new innovative discoveries in cancer treatments. In the past few decades, increased attention has been given to researches in alternative cancer treatment strategies using plants and plant products. Recently many anticancer drugs from natural products or phytochemicals were approved internationally. Due to the low bioavailability and poor solubility of phytochemicals, various research works on nano-carrier based drug delivery systems were exploited in the recent past to make them as promising anticancer agents. In the current review, an overview of oral cancer and its treatment, risk factors, missing links of conventional therapies, contribution of nanotechnology in cancer treatment and research on phytochemical based drug treatment and different polymeric nanoparticles were discussed briefly. The future prospects for the use of various types of polymeric nanoparticles applied in the diagnosis and treatment of oral cancer were also mentioned. The major concern of this review is to give the reader a better understanding on various types of treatment for oral cancer.

Advances in nanotechnology-based approaches for the treatment of head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC), one of the most common types of cancers occurring in the head and neck region, is often associated with high mortality rates due to its invasiveness and morbidity. The mainstream treatment methods in clinical settings, including surgery, chemotherapy, and radiotherapy, may cause poor overall survival rate and prognosis, with issues such as drug resistance, damage to adjacent healthy tissues, and potential recurrences. Other treatment approaches such as immunotherapy, photodynamic therapy (PDT), and photothermal therapy (PPT) also suffer from inefficient tumor targeting and suboptimal therapeutic outcomes. Early detection is vital for HNSCC patients, but it is always limited by insensitivity and confusing clinical manifestations. Hence, it is highly desirable to develop optimized therapeutic and diagnostic strategies. With the boom in nanomaterials, nanotechnology-conducted HNSCC therapy has attracted widespread attention. Nanoparticles (NPs) are distinguished by their unique morphology and superior physicochemical property, and some can exhibit direct antitumor activity, while others serve as promising candidates for drug delivery. In addition, NPs offer the potential for structural modification for drug delivery and tumor targeting, enabling specific delivery to tumor cells through conjugation with biomarker ligands and improving cargo biocompatibility. This work reviews current therapies and diagnosis methods for HNSCC, highlights the characteristics of the major NPs, surveys their uses and advantages in the treatment of HNSCC, and discusses the obstacles and prospects in clinical applications, aiming to enlighten future research directions for nanotechnology-based therapy for HNSCC.

Bimetallic Gold/Silver and Bioactive Camptothecin Hybrid Nanoparticles for Eradication of Cancer Stem Cells in a Combination Manner

The defeat of cancer is still a challenge due to the existence of cancer stem cells (CSCs) because they resist conventional chemotherapy via multifactor regulated mechanisms. Consequently, one-dimensional action toward CSCs cannot work. Herein, we used rationally designed hybrid nanoparticles as a combined cancer therapy, hoping to form a multidimensional control network. In this paper, gold/silver alloy nanoparticle decorated camptothecin nanocrystals were formulated according to complementary anti-CSC mechanisms from gold, silver, and organic drug. This smart drug formulation could combine chemotherapy and thermotherapy, target different tumor sites, and demonstrate versatile toxicity profiles from each component. Major results indicated that this nanosystem demonstrated indiscriminately effective cytotoxic/proapoptotic/necrotic activity against bulk MCF-7 cells and their CSC subpopulation, in particular under laser ablation. Moreover, this nanosystem displayed enhanced antineoplastic activity against CSC spheroids, resulting in a significant reduction in their number and size, that is, their self-renewal capacity. All the results indicated that CSCs upon treatment of these new hybrid nanoparticles underwent reduced stemness and conversion from the original quiescent state and recovered their sensitivity toward chemotherapy. The relevant anticancer mechanism was ascribed to NIR-pH dual responsive drug release, synergistic/combined thermo-chemotherapy of organic drug and inorganic alloy nanoparticles, enhanced cellular uptake mediated by alloy nanoparticles, and Ag+-induced biomembrane damage. This thermo-chemotherapy platform provides a new combinatorial strategy for inorganic and organic agents in the complete elimination of CSCs.

A Green Synthesis of Au-Ag Alloy Nanoparticles using Polydopamine Chemistry: Evaluation of their Anticancer Potency Towards Both MCF-7 Cells and their Cancer Stem Cells Subgroup

BACKGROUND

Limited chemotherapy efficacy and cancer stem cells (CSCs)-induced therapeutic resistance are major difficulties for tumour treatment. Adopting more efficient therapies to eliminate bulk-sensitive cancer cells and resistant CSCs is urgently needed.

METHODS

Based on the potential and functional complementarity of gold and silver nanoparticles (AuNPs or AgNPs) on tumour treatment, bimetallic NPs (alloy) have been synthesized to obtain improved or even newly emerging bioactivity from a combination effect. This study reported a facile, green and economical preparation of Au-Ag alloy NPs using biocompatible polydopamine (PDA) as a reductant, capping, stabilizing and hydrophilic agent.

RESULTS

These alloy NPs were quasi-spherical with rough surfaces and recorded in diameters of 80 nm. In addition, these alloy NPs showed good water dispersity, stability and photothermal effect. Compared with monometallic counterparts, these alloy NPs demonstrated a dramatically enhanced cytotoxic/pro-apoptotic/necrotic effect towards bulk-sensitive MCF-7 and MDA-MB-231 cells. The underlying mechanism regarding the apoptotic action was associated with a mitochondria-mediated pathway, as evidenced by Au3+/Ag+ mediated Mitochondria damage, ROS generation, DNA fragmentation and upregulation of certain apoptotic-related genes (Bax, P53 and Caspase 3). Attractively, these Au-Ag alloy NPs showed a remarkably improved inhibitory effect on the mammosphere formation capacity of MCF-7 CSCs.

CONCLUSION

All the positive results were attributed to incorporated properties from Au, Ag and PDA, the combination effect of chemotherapy and photothermal therapy and the nano-scaled structure of Au-Ag alloy NPs. In addition, the high biocompatibility of Au-Ag alloy NPs supported them as a good candidate in cancer therapy.

Transition metals in angiogenesis - A narrative review

The aim of this paper is to offer a narrative review of the literature regarding the influence of transition metals on angiogenesis, excluding lanthanides and actinides. To our knowledge there are not any reviews up to date offering such a summary, which inclined us to write this paper. Angiogenesis describes the process of blood vessel formation, which is an essential requirement for human growth and development. When the complex interplay between pro- and antiangiogenic mediators falls out of balance, angiogenesis can quickly become harmful. As it is so fundamental, both its inhibition and enhancement take part in various diseases, making it a target for therapeutic treatments. Current methods come with limitations, therefore, novel agents are constantly being researched, with metal agents offering promising results. Various transition metals have already been investigated in-depth, with studies indicating both pro- and antiangiogenic properties, respectively. The transition metals are being applied in various formulations, such as nanoparticles, complexes, or scaffold materials. Albeit the increasing attention this field is receiving, there remain many unanswered questions, mostly regarding the molecular mechanisms behind the observed effects. Notably, approximately half of all the transition metals have not yet been investigated regarding potential angiogenic effects. Considering the promising results which have already been established, it should be of great interest to begin investigating the remaining elements whilst also further analyzing the established effects.

Quinacrine and Curcumin in combination decreased the breast cancer angiogenesis by modulating ABCG2 via VEGF A

Cancer stem cells (CSCs) cause drug resistance in cancer due to its extensive drug efflux, DNA repair and self-renewal capability. ATP binding cassette subfamily G member 2 (ABCG2) efflux pump afford protection to CSCs in tumors, shielding them from the adverse effects of chemotherapy. Although the role of ABCG2 in cancer progression, invasiveness, recurrence are known but its role in metastasis and angiogenesis are not clear. Here, using in vitro (CSCs enriched side population [SP] cells), ex vivo (patient derived primary cells), in ovo (fertilized egg embryo) and in vivo (patient derived primary tissue mediated xenograft (PDX)) system, we have systematically studied the role of ABCG2 in angiogenesis and the regulation of the process by Curcumin (Cur) and Quinacrine (QC). Cur + QC inhibited the proliferation, invasion, migration and expression of representative markers of metastasis and angiogenesis. Following hypoxia, ABCG2 enriched cells released angiogenic factor vascular endothelial growth factor A (VEGF A) and induced the angiogenesis via PI3K-Akt-eNOS cascade. Cur + QC inhibited the ABCG2 expression and thus reduced the angiogenesis. Interestingly, overexpression of ABCG2 in SP cells and incubation of purified ABCG2 protein in media induced the angiogenesis but knockdown of ABCG2 decreased the vascularization. In agreement with in vitro results, ex vivo data showed similar phenomena. An induction of vascularization was noticed in PDX mice but reduction of vascularization was also observed after treatment of Cur + QC. Thus, data suggested that in hypoxia, ABCG2 enhances the production of angiogenesis factor VEGF A which in turn induced angiogenesis and Cur + QC inhibited the process by inhibiting ABCG2 in breast cancer.

Applications of Silver Nanoparticles in Dentistry

Silver nanoparticles (AgNPs) have been effectively applicable in most regions because of their antimicrobial activity against various microorganisms. AgNPs can be applied in disinfection and prophylaxis and to prevent diseases of the oral cavity. Because of developing interest in AgNPs, this article shows the application of AgNPs in various fields of dentistry such as nanocomposites, implant coatings, inhibiting the growth of bacteria, preventing dental caries, biofilm, infectious microbes, local anesthesia, microorganisms causing damage to the pulp, as well as deals with diseases such as oral malignancies due to their antitumor properties. AgNPs have a potential system with major features including antibacterial, anti-inflammatory, and anticancer action. They may also be used as a sustained drug delivery vehicle.

Therapeutic significance of molecular hybrids for breast cancer research and treatment

Worldwide, breast cancer is still a leading cause of cancer death in women. Indeed, over the years, several anti-breast cancer drugs have been developed; however, the complex heterogeneous nature of breast cancer disease reduces the applicability of conventional targeted therapies with the upsurge in side effects and multi-drug resistance. Molecular hybrids generated by a combination of two or more active pharmacophores emerged as a promising approach in recent years for the design and synthesis of anti-breast cancer drugs. The hybrid anti-breast cancer molecules are well known for their several advantages compared to the parent moiety. These hybrid forms of anti-breast cancer molecules demonstrated remarkable effects in blocking different pathways contributing to the pathogenies of breast cancer and improved specificity. In addition, these hybrids are patient compliant with reduced side effects and multi-drug resistance. The literature revealed that molecular hybrids are applied to discover and develop novel hybrids for various complex diseases. This review article highlights the recent progress (∼2018-2022) in developing molecular hybrids, including linked, merged, and fused hybrids, as promising anti-breast cancer agents. Furthermore, their design principles, biological potential, and future perspective are discussed. The provided information will lead to the development of novel anti-breast cancer hybrids with excellent pharmacological profiles in the future.

Insight on nano drug delivery systems with targeted therapy in treatment of oral cancer

Oral cancer is a type of cancer that develops in the mouth and is one of the deadliest malignancies in the world. Currently surgical, radiation therapy, and chemotherapy are most common treatments. Better treatment and early detection strategies are required. Chemotherapeutic drugs fail frequently due to toxicity and poor tumor targeting. There are high chances of failure of chemotherapeutic drugs due to toxicity. Active, passive, and immunity-targeting techniques are devised for tumor-specific activity. Nanotechnology-based drug delivery systems are the best available solution and important for precise targeting. Nanoparticles, liposomes, exosomes, and cyclodextrins are nano-based carriers for drug delivery. Nanotechnology is being used to develop new techniques such as intratumoral injections, microbubble mediated ultrasonic therapy, phototherapies, and site-specific delivery. This systematic review delves into the details of such targeted and nano-based drug delivery systems in order to improve patient health and survival rates in oral cancer.

Polyester nanomedicines targeting inflammatory signaling pathways for cancer therapy

The growth of cancerous cells and their responses towards substantial therapeutics are primarily controlled by inflammations (acute and chronic) and inflammation-associated products, which either endorse or repress tumor progression. Additionally, major signaling pathways, including NF-κB, STAT3, inflammation-causing factors (cytokines, TNF-α, chemokines), and growth-regulating factors (VEGF, TGF-β), are vital regulators responsible for the instigation and resolution of inflammations. Moreover, the conventional chemotherapeutics have exhibited diverse limitations, including poor pharmacokinetics, unfavorable chemical properties, poor targetability to the disease-specific disease leading to toxicity; thus, their applications are restricted in inflammation-mediated cancer therapy. Furthermore, nanotechnology has demonstrated potential benefits over conventional chemotherapeutics, such as it protected the incorporated drug/bioactive moiety from enzymatic degradation within the systemic circulation, improving the physicochemical properties of poorly aqueous soluble chemotherapeutic agents, and enhancing their targetability in specified carcinogenic cells rather than accumulating in the healthy cells, leading reduced cytotoxicity. Among diverse nanomaterials, polyester-based nanoparticulate delivery systems have been extensively used to target various inflammation-mediated cancers. This review summarizes the therapeutic potentials of various polyester nanomaterials (PLGA, PCL, PLA, PHA, and others)-based delivery systems targeting multiple signaling pathways related to inflammation-mediated cancer.

Green Synthesis of Gold Nanoparticles and Study of Their Inhibitory Effect on Bulk Cancer Cells and Cancer Stem Cells in Breast Carcinoma

Chemo-resistance from cancer stem cells (CSCs) subpopulation is a current issue in cancer treatment. It is important to select alternative therapies to efficiently eradicate both bulk cancer cells and CSCs. Here, gold nanoparticles (AuNPs) have been selected regarding their biocompatibility, facile and controllable synthesis, potent anti-cancer activity and photothermal conversion performance. We reported a green synthesis of functionalized AuNPs using hyaluronic acid (HA) as a reductant, capping, stabilizing and hydrophilic substance. The resultant AuNPs were spherical-shaped with an average diameter of around 30 nm. These AuNPs displayed improved physico-chemical (yield, stability, photothermal effect) and biological properties (cellular uptake, cytotoxicity and apoptotic effect) against bulk MDA-MB-231 cells, in comparison with other organic anti-cancer drugs. The intensified bioactivity was dependent on a mitochondria-mediated cascade, reflected by the damage in mitochondria, oxidative stress, intensified Caspase 3 activity and increased/decreased expression of certain pro-apoptotic (Bax, P53, Caspase 3)/anti-apoptotic (Bcl-2) genes. Moreover, these AuNPs posed a dramatically improved inhibitory effect in cell viability and self-renewable capacity on CSC subpopulation. All the results were attributed from the nano-scaled structure of AuNPs and combined effect from NIR-induced hyperthermia. In addition, the biocompatible nature of these AuNPs supported them to be a potential candidate in the development of novel chemotherapeutic drugs.

Gold Nanoparticle-Decorated Drug Nanocrystals for Enhancing Anticancer Efficacy and Reversing Drug Resistance Through Chemo-/Photothermal Therapy

Limited chemotherapeutic efficiency, drug resistance, and side effects are primary obstacles for cancer treatment. The development of co-delivery systems with synergistic treatment modes should be a promising strategy. Here, we fabricated a multifunctionalized nanocarrier with a combination of chemotherapeutic agents and gold nanoparticles (AuNPs), which could integrate chemo-photothermal therapy, thus enhancing overall anticancer efficacy, sensitizing drug-resistant cancer cells, and diminishing cancer stem cells (CSCs). To be specific, camptothecin nanocrystals (CPT NCs) were prepared as a platform, on the surface of which AuNPs were decorated and a hyaluronic acid layer acted as capping, stabilizing, targeting, and hydrophilic agents for CPT NCs, and reducing agents for AuNPs, providing a bridge connecting AuNPs to CPT. These AuNP-decorated CPT NCs exhibited good physico-chemical properties such as optimal sizes, payload, stability, and photothermal efficiency. Compared to other CPT formulations, they displayed considerably improved biocompatibility, selectivity, intracellular uptake, cytotoxicity, apoptosis induction activity, Pgp inhibitory capability, and anti-CSC activity, owing to a synergistic/cooperative effect from AuNPs, CPT, near-infrared treatment, pH/photothermal-triggered drug release, and nanoscaled structure. A mitochondrial-mediated signaling pathway is the underlying mechanism for cytotoxic and apoptotic effects from AuNP-decorated CPT NCs, in terms of mitochondrial dysfunction, intensified oxidative stress, DNA fragmentation, caspase 3 activation, upregulation of proapoptotic genes such as p53, Bax, and caspase 3, and lower levels of antiapoptotic Bcl-2.

A Review on the Application of Silver Nanoparticles in Oral and Maxillofacial Surgery

Silver nanoparticles (AgNPs) have been taken advantage of in dentistry because of their good antibacterial resistance and self-sustaining potential. However, in oral and maxillofacial surgery and implantology, there is a lesser amount of evidence. The few pieces of evidence need to be accentuated for possible amplification of its use in the dental setting. AgNPs in oral and maxillofacial surgery can be used in wound healing, bone healing, extractions, guided tissue regeneration, apical surgeries, oral cancer, and dental implants. This review aims to feature the utilization and application of AgNPs in oral and maxillofacial surgery and implant dentistry, emphasizing its need for potential future development in clinical settings.

Anti-Cancer Stem Cells Potentiality of an Anti-Malarial Agent Quinacrine: An Old Wine in a New Bottle

Quinacrine (QC) is a tricyclic compound and a derivative of 9-aminoacridine. It has been widely used to treat malaria and other parasitic diseases since the last century. Interestingly, studies have revealed that it also displays anti-cancer activities. Here, we have discussed the anti-cancer mechanism of QC along with its potentiality to specifically target cancer stem cells. The anti-cancer action of this drug includes DNA intercalation, inhibition of DNA repair mechanism, prevention of cellular growth, cell cycle arrest, inhibition of DNA and RNA polymerase activity, induction of autophagy, promotion of apoptosis, deregulation of cell signaling in cancer cells and cancer stem cells, inhibition of metastasis and angiogenesis. In addition, we have also emphasized on the synergistic effect of this drug with other potent chemotherapeutic agents and mentioned its different applications in anti-cancer therapy.

Silver nanoparticles functionalized Paclitaxel nanocrystals enhance overall anti-cancer effect on human cancer cells

For chemotherapeutic drugs, precise tumor-targeting and high anti-cancer efficiency is equally important in order to enhance chemotherapy and reverse drug resistance. The combination of multifunctional agents to achieve synergy should be a promising strategy. In our study, we have successfully developed novel multifunctionalized drug nanocrystals to realize co-delivery of the organic drug Paclitaxel (PTX), inorganic silver nanoparticles (AgNPs) and a tumor targeting agent. To be specific, PTX nanocrystals were first prepared as a template, then coated with polydopamine (PDA). The PDA layer was utilized as the connection bridge to produce and deposit AgNPs in situ, and provide sites for tumor-targeting peptide NR1 (RGDARF) grafting. As a result, these NR1/AgNP-decorated drug nanocrystals exhibited dramatically improved cellular uptake efficiency, in vitro anti-cancer activity and an anti-migratory effect against a variety of cancer cells, which was attributable to the synergistic, or at least additive, effect of the AgNPs and PTX, enhanced cellular uptake efficiency through NR1-receptor interaction, pH-responsive drug release and the nanoscaled nature. In particular, high anti-cancer activity and low side effects from these NR1/AgNP-decorated PTX nanocrystals were well balanced in terms of good selectivity and biocompatibility. Moreover, these novel drug nanocrystals displayed strong apoptotic-inducing potency, resulting in cell membrane lysis, nuclear damage, mitochondria dysfunction, excessive ROS release and double-stranded DNA breakage. The potential acting mechanism and molecular basis of these novel drug nanocrystals is relevant to the regulation of mitochondria-mediated apoptosis with a greater Bax-to-Bcl-2 ratio and the activation of pro-apoptotic P53 and caspase 3.

Undaria pinnatifida fucoidan nanoparticles loaded with quinacrine attenuate growth and metastasis of pancreatic cancer

Pancreatic cancer is a devastating gastrointestinal tumor with limited Chemotherapeutic options. Treatment is restricted by its poor vascularity and dense surrounding stroma. Quinacrine is a repositioned drug with an anticancer activity but suffers a limited ability to reach tumor cells. This could be enhanced using nanotechnology by the preparation of quinacrine-loaded Undaria pinnatifida fucoidan nanoparticles. The system exploited fucoidan as both a delivery system of natural origin and active targeting ligand. Lactoferrin was added as a second active targeting ligand. Single and dual-targeted particles prepared through nanoprecipitation and ionic interaction respectively were appraised. Both particles showed a size lower than 200 nm, entrapment efficiency of 80% and a pH-dependent release of the drug in the acidic environment of the tumor. The anticancer activity of quinacrine was enhanced by 5.7 folds in dual targeted particles compared to drug solution with a higher ability to inhibit migration and invasion of cancer. In vivo, these particles showed a 68% reduction in tumor volume compared to only 20% for drug solution. In addition, they showed a higher animals' survival rate with no hepatotoxicity. Hence, these particles could be an effective option for the eradication of pancreatic cancer cells.

Nanoformulated quinacrine regulates NECTIN-4 domain specific functions in cervical cancer stem cells

NECTIN-4 [a poliovirus receptor-related-4 (PVRL-4) encoded gene] has vital roles in cancer proliferation, metastasis and angiogenesis. It possesses three different domains and it is predicted that they have different roles in cancer but the structure-function relationship is still unknown and hence carrying out a detailed study to elucidate the domain-specific functions of NECTIN-4 in cancer is necessary. Using 5-Fluouracil-resistant cervical cancer stem cells (PEMT-5FU-R-MC) and different NECTIN-4 domain-specific constructs, different domains of NECTIN-4 were over-expressed in PEMT-5FU-R-MC cells. Biochemical assays like comet, γ-H2AX immunofluorescence, western blot, in vitro tube formation, gelatin zymography, in ovo CAM assay, etc. were used to delineate the function of each domain of NECTIN-4 in cancer and their regulation by nano-formulated quinacrine (NQC). Endo-domain (lacking extracellular region corresponding to aa 30-347) and ecto-domain (lacking signal peptide and cytoplasmic region corresponding to aa 1-29 and 348-509, respectively) of NECTIN-4 were largely overexpressed in nucleus and cytoplasm, respectively. Endo-domain translocates into nucleus by physically interacting with IMPORTIN-α2, activates the DNA repair and enhances cell growth, whereas ecto-domain specifically activates angiogenesis by modulating representative angiogenic markers, inducing in vitro tube formation and in ovo blood vessel formation. Full-length NECTIN-4 (aa 1-509) was overexpressed in both nucleus and cytoplasm and modulated both DNA repair and angiogenesis. NQC down-regulated these phenomena by modulating the endo-domain and ecto-domain of NECTIN-4. Thus, current study suggested that endo-domain of NECTIN-4 translocated into nucleus and increased the DNA repair and ecto-domain of NECTIN-4 enhanced the angiogenesis, whereas NQC inhibits these processes.

Repurposing Quinacrine for Treatment of Malignant Mesothelioma: In-Vitro Therapeutic and Mechanistic Evaluation

Malignant mesothelioma (MM) is a rare type of cancer primarily affecting mesothelial cells lining the pleural cavity. In this study, we propose to repurpose quinacrine (QA), a widely approved anti-malarial drug, for Malignant Pleural Mesothelioma (MPM) treatment. QA demonstrates high degree of cytotoxicity against both immortalized and primary patient-derived cell lines with sub-micromolar 50% inhibitory concentration (IC₅₀) values ranging from 1.2 µM (H2452) to 5.03 µM (H28). Further, QA also inhibited cellular migration and colony formation in MPM cells, demonstrated using scratch and clonogenic assays, respectively. A 3D-spheroid cell culture experiment was performed to mimic in-vivo tumor conditions, and QA was reported to be highly effective in this simulated cellular model. Anti-angiogenic properties were also discovered for QA. Autophagy inhibition assay was performed, and results revealed that QA successfully inhibited autophagy process in MPM cells, which has been cited to be one of the survival pathways for MPM. Annexin V real-time apoptosis study revealed significant apoptotic induction in MPM cells following QA treatment. Western blots confirmed inhibition of autophagy and induction of apoptosis. These studies highlight anti-mesothelioma efficacy of QA at low doses, which can be instrumental in developing it as a stand-alone treatment strategy for MPM.

Nano Drug Delivery in Treatment of Oral Cancer, A Review of the Literature

Oral Cancer (OC) is a serious and growing problem which constitutes a huge burden on people in more and less economically developed countries alike. The scenario is clearly depicted from the increase in the expected number of new cases in the US diagnosed with OC from 49,670 people in 2016, to 49,750 cases in 2017. The situation is even more alarming in India, with 75,000 to 80,000 new cases being reported every year, thus making it the OC capital of the world. Leukoplakia, erythroplakia, oral lichen planus, oral submucous fibrosis, discoid lupus erythmatosus, hereditary disorders such as dyskeratosis congenital and epidermolisys bullosa are highlighted by WHO expert working group as the predisposing factors increasing the risk of OC. Consumption of tobacco and alcohol, genetic factors, and human papilloma virus are assigned as the factors contributing to the aetiology of OC. On the other hand, pathogenesis of OC involves not only apoptosis but also pain, inflammation and oxidative stress. Inspite of current treatment options (surgery, radiotherapy, and chemotherapy), OC is often associated with recurrence and formation of secondary primary tumours resulting in poor overall survival rates (∼50%). The intervention of nano technology-based drug delivery systems as therapeutics for cancers is often viewed as a cutting edge for technologists. Though ample literature on the usefulness of nano-coutured cancer therapeutics, rarely any product is in pipeline. Yet, despite all the hype about nanotechnology, there are few ongoing trials. This review discusses the current and future trends of nano-based drug delivery for the treatment of OC.

Quinacrine Based Gold Hybrid Nanoparticles Caused Apoptosis through Modulating Replication Fork in Oral Cancer Stem Cells

The presence of cancer stem cells (CSCs) in the tumor microenvironment is responsible for the development of chemoresistance and recurrence of cancer. Our previous investigation revealed the anticancer mechanism of quinacrine-based silver and gold hybrid nanoparticles (QAgNP and QAuNP) in oral cancer cells, but to avoid cancer recurrence, it is important to study the effect of these nanoparticles (NPs) on CSCs. Here, we developed an in vitro CSCs model using SCC-9 oral cancer cells and validated via FACS analysis. Then, 40-60% of cells were found to be CD44+/CD133+ and CD24-. QAuNP showed excellent anti-CSC growth potential against SCC-9-cancer stem like cells (IC₅₀ = 0.4 μg/mL) with the down-regulation of representative CSC markers. Prolonged exposure of QAuNP induced the S-phase arrest and caused re-replication shown by the extended G2/M population and apoptosis to SCC-9-CSC like cells. Up-regulation of BAX, PARP cleavage, and simultaneous down-regulation of Bcl-xL in prolonged treatment to CSCs suggested that the majority of the cells have undergone apoptosis. QAuNP treatment also caused a loss in DNA repair in CSCs. Mostly, the base excision repair (BER) components (Fen-1, DNA ligase-1, Pol-β, RPA, etc.) were significantly down-regulated after QAuNP treatment, which suggested its action against DNA repair machinery. The replication fork maintenance-related proteins, RAD 51 and BRCA-2, were also deregulated. Very surprisingly, depletion of WRN (an interacting partner for Pre-RC and Fen-1) and a significant increase in expression of fork-degrading nuclease MRE-11 in 96 h treated NPs were observed. Results suggest QAuNP treatment caused excessive DNA damage and re-replication mediated replication stress (RS) and stalling of the replication fork. Inhibition of BER components hinders the flap clearance activity of Fen-1, and it further caused RS and stopped DNA synthesis. Overall, QAuNP treatment led to irreparable replication fork movement, and the stalled replication fork might have degraded by MRE-11, which ultimately results in apoptosis and the death of the CSCs.

Progress in Drug and Formulation Development for the Chemoprevention of Oral Squamous Cell Carcinoma: A Review

BACKGROUND

Cancer is a life-threatening global problem with high incidence rates. Prioritizing the prevention of cancer, chemopreventive agents have drawn much attention from the researchers.

OBJECTIVE

This review focuses on the discussion of the progress in the development of chemopreventive agents and formulations related to the prevention of oral cancer.

METHODS

In this perspective, an extensive literature survey was carried out to understand the mechanism, control and chemoprevention of oral cancer. Different patented agents and formulations have also exhibited cancer preventive efficacy in experimental studies. This review summarizes the etiology of oral cancer and developments in prevention strategies.

RESULTS

The growth of oral cancer is a multistep activity necessitating the accumulation of genetic as well as epigenetic alterations in key regulatory genes. Many risk factors are associated with oral cancer. Genomic technique for sequencing all tumor specimens has been made available to help detect mutations. The recent development of molecular pathway and genetic tools has made the process of diagnosis easier, better forecast and efficient therapeutic management. Different chemical agents have been studied for their efficacy to prevent oral cancer and some of them have shown promising results.

CONCLUSION

Use of chemopreventive agents, either synthetic or natural origin, to prevent carcinogenesis is a worthy concept in the management of cancers. Preventive measures are helpful in controlling the occurrence or severity of the disease. The demonstrated results of preventive agents have opened an arena for the development of promising chemopreventive agents in the management of oral squamous cell carcinoma.

Clinical significance of a pvrl 4 encoded gene Nectin-4 in metastasis and angiogenesis for tumor relapse

PURPOSE

In the present study, we have systematically examined the clinical significance of Nectin-4 (encoded by the PVRL-4 gene), a marker for breast cancer stem cells (CSCs), in cancer metastasis and angiogenesis using a variety of human specimens, including invasive duct carcinoma (IDC) with multiple grades, several types of primary tumors to local and distant relapses, lymph node metastases and circulating tumor cells (CTCs).

METHODS

Nectin-4 was overexpressed in more than 92% of samples with 65.2% Nectin-4-positive cells. The level of expression was increased with increasing tumor grade (GI-III) and size (T1-4) of IDC specimens.

RESULTS

More induction of Nectin-4 was noted in relapsed samples from a variety of tumors (colon, tongue, liver, kidney, ovary, buccal mucosa) in comparison to primary tumors, while paired adjacent normal tissues do not express any Nectin-4. A high expression of Nectin-4 along with other representative markers in CTCs and lymph node metastasis was also observed in cancer specimens. An increased level of Nectin-4 along with representative metastatic (CD-44, Sca1, ALDH1, Nanog) and angiogenic (Ang-I, Ang-II, VEGF) markers were noted in metastatic tumors (local and distant) in comparison to primary tumors that were correlated with different grades of tumor progression. In addition, greater expression of Nectin-4 was observed in secondary tumors (distant metastasis, e.g., breast to liver or stomach to gall bladder) in comparison to primary tumors.

CONCLUSION

Our study demonstrated a significant correlation between Nectin-4 expression and tumor grade as well as stages (p < 0.001), suggesting its association with tumor progression. Nectin-4 was overexpressed at all stages of metastasis and angiogenesis, thus appearing to play a major role in tumor relapse through the PI3K-Akt-NFκβ pathway.

Silver nanoparticles for delivery purposes

The synthesis of nanostructured materials can be considered a research field of high importance, especially in the recent past, due to the unique properties that make these materials applicable in different fields of science and technology. Metallic nanoparticles gained significant interest due to the possibility to obtain them through biological means, among other techniques. Silver nanoparticles are some of the most investigated metallic nanoparticles, due to their recognized anticancer, antimicrobial, and antiviral potential. This chapter aims to summarize the emerging efforts to address current challenges and solutions in the treatment of infectious diseases, particularly through the use of silver nanoparticles biosynthesized via microbes and plants pathways.

Quinacrine and curcumin synergistically increased the breast cancer stem cells death by inhibiting ABCG2 and modulating DNA damage repair pathway

Cancer stem cell like cells (CSCs) present a challenge in the management of cancers due to their involvement in the development of resistance against various chemotherapeutic agents. Over expression of ABCG2 transporter gene is one of the factors responsible for drug resistance in CSCs, which causes efflux of therapeutic drugs from these cells. The development of inhibitors against CSCs has not achieved any significant success, till date. In this work, we have evaluated the anti-proliferative activity of curcumin (Cur) and quinacrine (QC) against CSCs using in vitro model system. Cur and QC synergistically inhibited the proliferation, migration and invasion of CSCs enriched side population (SP) cells of cigarette smoke condensate induced breast epithelial transformed (MCF-10A-Tr) generated metastatic cells. Cur + QC combination increased the DNA damage and inhibited the DNA repair pathways in SP cells. Uptake of QC increased in Cur pre-treated SP cells and this combination inhibited the ABCG2 activity by the reduction of ATP hydrolysis in cells. In vitro DNA binding reconstitution system suggests that QC specifically binds to DNA and caused DNA damage inside the cell. Decreased level of ABCG2, representative cell survival and DNA repair proteins were noted after Cur + QC treatment in SP cells. The molecular docking studies were performed to examine the binding behaviour of these drugs with ABCG2, which showed that QC (-53.99 kcal/mol) and Cur (-45.90 kcal/mol) occupy a highly overlapping interaction domain. This suggested that in Cur pre-treated cells, the Cur occupied the ligand-binding site in ABCG2, thus making the ligand binding site unavailable for the QC. This causes an increase in the intracellular concentration of QC. The results indicate that Cur + QC combination causes CSCs death by increasing the concentration of QC in the cells and thus causing the DNA damage and inhibiting the DNA repair pathways through modulating the ABCG2 activity.

Controlled Drug Delivery Systems for Oral Cancer Treatment-Current Status and Future Perspectives

Oral squamous cell carcinoma (OSCC), which encompasses the oral cavity-derived malignancies, is a devastating disease causing substantial morbidity and mortality in both men and women. It is the most common subtype of the head and neck squamous cell carcinoma (HNSCC), which is ranked the sixth most common malignancy worldwide. Despite promising advancements in the conventional therapeutic approaches currently available for patients with oral cancer, many drawbacks are still to be addressed; surgical resection leads to permanent disfigurement, altered sense of self and debilitating physiological consequences, while chemo- and radio-therapies result in significant toxicities, all affecting patient wellbeing and quality of life. Thus, the development of novel therapeutic approaches or modifications of current strategies is paramount to improve individual health outcomes and survival, while early tumour detection remains a priority and significant challenge. In recent years, drug delivery systems and chronotherapy have been developed as alternative methods aiming to enhance the benefits of the current anticancer therapies, while minimizing their undesirable toxic effects on the healthy non-cancerous cells. Targeted drug delivery systems have the potential to increase drug bioavailability and bio-distribution at the site of the primary tumour. This review confers current knowledge on the diverse drug delivery methods, potential carriers (e.g., polymeric, inorganic, and combinational nanoparticles; nanolipids; hydrogels; exosomes) and anticancer targeted approaches for oral squamous cell carcinoma treatment, with an emphasis on their clinical relevance in the era of precision medicine, circadian chronobiology and patient-centred health care.

Nanoquinacrine sensitizes 5-FU-resistant cervical cancer stem-like cells by down-regulating Nectin-4 via ADAM-17 mediated NOTCH deregulation

PURPOSE

Cervical cancer is a major cause of cancer-related death in women world-wide. Although the anti-metabolite 5-FU is widely used for its treatment, its clinical utility is limited due to the frequent occurrence of drug resistance during metastasis. Cancer stem-like cells (CSCs), present in the heterogeneous population of CC cells, are thought to contribute to this resistance. Nectin-4, a CSC marker, is known to play an important role in the cellular aggressiveness associated with metastatic CC. This study was designed to assess the role of Nectin-4 in the acquisition of 5-FU resistance by metastatic CC cells, including its relation to the NOTCH signalling pathway.

METHODS

5FU-resistant CC cell lines were deduced from ME-180 and SiHA cells by continuous exposure to a single concentration of 5-FU. Thymidylate synthase (TS) positive cells were isolated from the 5-FU resistant cells, after which a metastatic model was developed. The role of Nectin-4 in the sensitization of 5-FU resistant metastatic CC cells upon incubation with Nano-formulated Quinacrine (NQC) was investigated using multiple bioassays including MTT, FACS, ELISA, immunoflurescence, Western blotting, comet and in vivo plasmid-based short patch and long patch base excision repair assays.

RESULTS

We found that the expression level of Nectin-4, as well as that of other CSC markers (Oct-4, β-catenin, SOX2) and representative NOTCH signalling components (NOTCH-1, Jagged-1, γ-secretase, ADAM-17) were elevated in the 5-FU resistant metastatic cells compared to those in control cells. Increased nuclear translocation of Nectin-4 and increased proliferation and invasion rates were observed after culturing the metastatic cells under hypoxic conditions. Treatment with NQC inhibited the nuclear translocation of Nectin-4 and decreased the proliferation and invasion rates of the cells by inhibiting the induction of base excision repair (BER) pathway components and ADAM-17 expression levels. After combination treatment of Nectin-4 overexpressing metastatic CC cells with a specific ADAM-17 inhibitor (GW280264) and NQC, a decreased Nectin-4 expression, without alterations in BER and/or other NOTCH pathway components, was noted.

CONCLUSION

Our data indicate that Nectin-4 may play a prominent role in 5-FU resistance of metastatic CC cells and that NQC sensitizes these cells by Nectin-4 deregulation through ADAM-17 inhibition, a major component of the NOTCH signalling pathway.

The soluble nectin-4 ecto-domain promotes breast cancer induced angiogenesis via endothelial Integrin-β4

Cancer stem cells secrete diffusible factors into the microenvironment that bind to specific endothelial cell receptors and initiate an angiogenesis cascade. Tumor-induced angiogenesis is an important parameter of tumorigenesis and is critical for tumor growth and metastasis. A pvrl-4 encoded gene, NECTIN-4, has potential roles in cancer cell growth and aggressiveness, and it is only expressed in cancer cells. There is evidence that nectin-4 plays a role in tumorigenesis, but the function of nectin-4 in tumor angiogenesis has lacked thorough evidence of mechanism. Using highly metastatic breast cancer cells and human umbilical vein endothelial cells (HUVECs), we have developed an excellent angiogenesis model and systematically studied the contribution of nectin-4 to angiogenesis. We also provide in-depth in ovo, in vivo and in vivo evidence that nectin-4 causes angiogenesis. Following hypoxia, metastatic breast cancer stem cells (mBCSCs) driven ADAM-17 expression causes the shedding of the ecto-domain of nectin-4 into the microenvironment, which physically interacts with integrin-β4 specifically on endothelial cells. This interaction promotes angiogenesis via the Src, PI3K, AKT, iNOS pathway and not by Phospho-Erk or NF-κβ pathways. In vitro, in ovo and in vivo induction and abrogation of an angiogenesis cascade in the presence and absence of the nectin-4 ecto-domain, respectively, confirms its role in angiogenesis. Thus, disrupting the interaction between nectin-4 ecto-domain and integrin-β4 may provide a means of targeting mBCSC-induced angiogenesis.

A Current Overview of the Biological and Cellular Effects of Nanosilver

Nanosilver plays an important role in nanoscience and nanotechnology, and is becoming increasingly used for applications in nanomedicine. Nanosilver ranges from 1 to 100 nanometers in diameter. Smaller particles more readily enter cells and interact with the cellular components. The exposure dose, particle size, coating, and aggregation state of the nanosilver, as well as the cell type or organism on which it is tested, are all large determining factors on the effect and potential toxicity of nanosilver. A high exposure dose to nanosilver alters the cellular stress responses and initiates cascades of signalling that can eventually trigger organelle autophagy and apoptosis. This review summarizes the current knowledge of the effects of nanosilver on cellular metabolic function and response to stress. Both the causative effects of nanosilver on oxidative stress, endoplasmic reticulum stress, and hypoxic stress—as well as the effects of nanosilver on the responses to such stresses—are outlined. The interactions and effects of nanosilver on cellular uptake, oxidative stress (reactive oxygen species), inflammation, hypoxic response, mitochondrial function, endoplasmic reticulum (ER) function and the unfolded protein response, autophagy and apoptosis, angiogenesis, epigenetics, genotoxicity, and cancer development and tumorigenesis—as well as other pathway alterations—are examined in this review.

Novel applications for an established antimalarial drug: tumoricidal activity of quinacrine

Quinacrine (QC), a synthetic antimalarial drug, was consistently used worldwide to combat malaria during the last century. Interestingly, later studies revealed that it also displays various additional properties, specifically antitumor activity. QC's antitumor activity occurs via a variety of pathways, including DNA intercalation, angiogenesis inhibition, signal transduction regulation, cell cycle arrest and autophagy induction. In combination with traditional therapies such as chemotherapy and radiotherapy, QC has also displayed synergistic effects against tumors, which may open promising therapeutic avenues. However, the breadth and complexity of its antitumor mechanisms have not yet been fully elucidated. In this review, we have systematically categorized QC's reported antitumor mechanisms from recent studies, to enable a deeper understanding of its antitumor activity.

Cancer stem cells (CSCs), cervical CSCs and targeted therapies

Accumulating evidence has shown that cancer stem cells (CSCs) have a tumour-initiating capacity and play crucial roles in tumour metastasis, relapse and chemo/radio-resistance. As tumour propagation initiators, CSCs are considered to be promising targets for obtaining a better therapeutic outcome. Cervical carcinoma is the most common gynaecological malignancy and has a high cancer mortality rate among females. As a result, the investigation of cervical cancer stem cells (CCSCs) is of great value. However, the numbers of cancer cells and corresponding CSCs in malignancy are dynamically balanced, and CSCs may reside in the CSC niche, about which little is known to date. Therefore, due to their complicated molecular phenotypes and biological behaviours, it remains challenging to obtain “purified” CSCs and continuously culture CSCs for further in vitro studies without the cells losing their stem properties. At present, CSC-related markers and functional assays are used to purify, identify and therapeutically target CSCs both in vitro and in vivo. Nevertheless, CSC-related markers are not universal to all tumour types, although some markers may be valid in multiple tumour types. Additionally, functional identifications based on CSC-specific properties are usually limited in in vivo studies. Furthermore, an optimal method for identifying potential CCSCs in CCSC studies has not been previously published, and these techniques are currently of great importance. This article updates our knowledge on CSCs and CCSCs, reviews potential stem cell markers and functional assays for identifying CCSCs, and describes the potential of targeting CCSCs in the treatment of cervical carcinoma.

Quinacrine induces apoptosis in cancer cells by forming a functional bridge between TRAIL-DR5 complex and modulating the mitochondrial intrinsic cascade

Death Receptor 5 (DR5) is known to be an important anti-cancer drug target. TRAIL is a natural ligand of DR5, but its drug action is limited because of several factors. A few agonistic ligands were identified as TRAIL-DR5 axis modulators, which enhance the cellular apoptosis. Literature suggest that quinacrine (QC) acts as a DR5 agonistic ligand. However, the detailed mechanism explaining how QC interacts with TRAIL-DR5 axis has not been established. Also focused in vitro and in vivo experimental analysis to validate the hypothesis is not yet performed. In this work, extensive studies have been carried out using in silico analysis (molecular dynamics), in vitro analysis (cell based assays) and in vivo analysis (based on mice xenograft model), to delineate the mechanism of QC action in modulating the TRAIL-DR5 signaling. The MD simulations helped in identifying the important residues contributing to the formation of a QC-TRAIL-DR5 complex, which provide extra stability to it, consequently leading to the enhanced cellular apoptosis. QC caused a dose dependent increase of DR5 expression in cancer cells but not in normal breast epithelial cells, MCF-10A. QC showed a synergistic effect with TRAIL in causing cancer cell apoptosis. In DR5-KD MCF-10A-Tr (DR5 knocked down) cells, TRAIL+ QC failed to significantly increase the apoptosis but over expression of full length DR5 in DR5-silence cells induced apoptosis, further supporting DR5 as a drug target for QC. An increase in the release of reactive species (ROS and RNS) and activation of enzymes (FADD, CASPASES 3, 8, 9 and cytochrome-C) indicated the involvement of mitochondrial intrinsic pathway in TRAIL+QC mediated apoptosis. In vivo study pointed out that TRAIL+QC co-administration increases the expression of DR5 and reduce the tumor size in xenograft mice. This combined in silico, in vitro and in vivo analysis revealed that QC enhances the cellular apoptosis via the modulation of TRAIL-DR5 complexation and the mitochondrial intrinsic pathway.

Metallic gold and bioactive quinacrine hybrid nanoparticles inhibit oral cancer stem cell and angiogenesis by deregulating inflammatory cytokines in p53 dependent manner

Complete eradication of aggressive oral cancer remains a challenge due to the presence of CSCs. They resist conventional chemotherapeutic agents due to their self-renewal, drug efflux, and efficient DNA repair capacity. Here, we formulated a hybrid-nanoparticle (QAuNP) using quinacrine and gold and characterized/investigated its anti-angiogenic and anti-metastatic effect on OSCC-CSCs. QAuNP significantly inhibited cellular proliferation, caused apoptosis in vitro, and disrupted angiogenesis in vivo and tumor regression in xenograft mice model. It not only inhibited crucial angiogenic markers Ang-1, Ang-2 and VEGF but also depleted MMP-2 in H-357-PEMT cells in a p53 and p21-dependent manner. QAuNP also increased the ROS and NO generation in OSCC-CSCs and reduced the mitochondrial membrane potential. It altered the level of inflammatory cytokines IL-6, IL-1β, TNF-α and metastasis-associated markers (CD-44, CD-133) in H-357-PEMT and CM-treated endothelial cells (HUVEC) in p53/p21-dependent manner. Therefore, QAuNP will be a useful therapeutic agent against metastatic OSCC.

Design and synthesis of novel quinacrine-[1,3]-thiazinan-4-one hybrids for their anti-breast cancer activity

In an attempt to develop effective and safe anticancer agents, we designed, synthesized and examined 23 novel quinacrine (QC) derivatives by combining the 9-aminoacridine scaffold and the [1,3]thiazinan-4-ones group. Most of these hybrids showed strong anticancer activities, among which 3-(3-(6-chloro-2-methoxyacridin-9-ylamino)propyl)-2-(thiophen-2-yl)-1,3-thiazinan-4-one (25; VR151) effectively killed many different cancer cell types, including eight breast cancer cell lines with different genetic background, two prostate cancer and two lung cancer cell lines. In contrast, compound 25 is less effective against non-cancer cells, suggesting it may be less toxic to humans. Our data showed that cancer cells are arrested in S phase for a prolonged period due to the down-regulation of DNA replication, leading to eventual cell death. We have also shown that the S phase arrest may be resulted by the down-regulation of cyclin A coupled with the continued up-regulation of cyclin E, which coincide with the down-regulation of mTor-S6K and mTor-4EBP1 pathways.

Nanomedicine, an emerging therapeutic strategy for oral cancer therapy

Oral cavity and oropharyngeal carcinomas (oral cancer) represents a significant cause of morbidity and mortality. Despite efforts in improving early diagnosis and treatment, the 5-year survival rate of advanced stage of the disease is less than 63%. The field of nanomedicine has offered promising diagnostic and therapeutic advances in cancer. Indeed, several platforms have been clinically approved for cancer therapy, while other promising systems are undergoing exploration in clinical trials. With its ability to deliver drugs, nucleic acids, and MRI contrast agents with high efficiency, nanomedicine platforms offer the potential to improve drug efficacy and tolerability. The aim of the present mini-review is to summarize the current preclinical status of nanotechnology systems for oral cancer therapy. The nanoplatforms for delivery of chemopreventive agents presented herein resulted in significantly higher anti-tumor activity than free forms of the drug, even against a chemo-resistant cell line. Impressive results have also been obtained using nanoparticles to deliver chemotherapeutics, resulting in reduced toxicity both in vitro and in vivo. Nanoparticles have also led to improvements in efficacy of photodynamic therapies through the development of targeted magnetic nanoparticles. Finally, gene therapy using nanoparticles demonstrated promising results specifically with regards to inhibition of gene expression. Of the few in vivo studies that have been reported, many of these used animal models with several limitations, which will be discussed herein. Lastly, we will discuss several future perspectives in oral cancer nanoparticle-based therapy and the development of appropriate animal models, distinguishing between oral cavity and oropharyngeal carcinoma.

Silver nanoparticles in dentistry

OBJECTIVE

Silver nanoparticles (AgNPs) have been extensively studied for their antimicrobial properties, which provide an extensive applicability in dentistry. Because of this increasing interest in AgNPs, the objective of this paper was to review their use in nanocomposites; implant coatings; pre-formulation with antimicrobial activity against cariogenic pathogens, periodontal biofilm, fungal pathogens and endodontic bacteria; and other applications such as treatment of oral cancer and local anesthesia. Recent achievements in the study of the mechanism of action and the most important toxicological aspects are also presented.

METHODS

Systematic searches were carried out in Web of Science (ISI), Google, PubMed, SciFinder and EspaceNet databases with the keywords "silver nano* or AgNP*" and "dentist* or dental* or odontol*".

RESULTS

A total of 155 peer-reviewed articles were reviewed. Most of them were published in the period of 2012-2017, demonstrating that this topic currently represents an important trend in dentistry research. In vitro studies reveal the excellent antimicrobial activity of AgNPs when associated with dental materials such as nanocomposites, acrylic resins, resin co-monomers, adhesives, intracanal medication, and implant coatings. Moreover, AgNPs were demonstrated to be interesting tools in the treatment of oral cancers due to their antitumor properties.

SIGNIFICANCE

The literature indicates that AgNPs are a promising system with important features such as antimicrobial, anti-inflammatory and antitumor activity, and a potential carrier in sustained drug delivery. However, there are some aspects of the mechanisms of action of AgNPs, and some important toxicological aspects arising from the use of this system that must be completely elucidated.

Exposure to Engineered Nanomaterials: Impact on DNA Repair Pathways

Some engineered nanomaterials (ENMs) may have the potential to cause damage to the genetic material in living systems. The mechanistic machinery functioning at the cellular/molecular level, in the form of DNA repair processes, has evolved to help circumvent DNA damage caused by exposure to a variety of foreign substances. Recent studies have contributed to our understanding of the various DNA damage repair pathways involved in the processing of DNA damage. However, the vast array of ENMs may present a relatively new challenge to the integrity of the human genome; therefore, the potential hazard posed by some ENMs necessitates the evaluation and understanding of ENM-induced DNA damage repair pathways. This review focuses on recent studies highlighting the differential regulation of DNA repair pathways, in response to a variety of ENMs, and discusses the various factors that dictate aberrant repair processes, including intracellular signalling, spatial interactions and ENM-specific responses.

Polymeric drug delivery systems for intraoral site-specific chemoprevention of oral cancer

Oral cancer is among the most prevalent cancers in the world. Moreover, it is one of the major health problems and causes of death in many regions of the world. The traditional treatment modalities include surgical removal, radiation therapy, systemic chemotherapy, or a combination of these methods. In recent decades, there has been significant interest in intraoral site-specific chemoprevention via local drug delivery using polymeric systems. Because of its easy accessibility and clear visibility, the oral mucosa is amenable for local drug delivery. A variety of polymeric systems-such as gels, tablets, films, patches, injectable systems (e.g., millicylindrical implants, microparticles, and in situ-forming depots), and nanosized carriers (e.g., polymeric nanoparticles, nanofibers, polymer-drug conjugates, polymeric micelles, nanoliposomes, nanoemulsions, and polymersomes)-have been developed and evaluated for the local delivery of natural and synthetic chemopreventive agents. The findings of in vitro, ex vivo, and in vivo studies and the positive outcome of clinical trials demonstrate that intraoral site-specific drug delivery is an attractive, highly effective and patient-friendly strategy for the management of oral cancer. Intraoral site-specific drug delivery provides unique therapeutic advantages when compared to systemic chemotherapy. Moreover, intraoral drug delivery systems are self-administrable and can be removed when needed, increasing patient compliance. This article covers important aspects and advances related to the design, development, and efficacy of polymeric systems for intraoral site-specific drug delivery. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1383-1413, 2018.

Chitosan-Dextran sulfate coated doxorubicin loaded PLGA-PVA-nanoparticles caused apoptosis in doxorubicin resistance breast cancer cells through induction of DNA damage

To overcome the toxicity, pharmacokinetics and drug resistance associated with doxorubicin (DOX), a strategy was developed by encapsulating DOX- loaded-PLGA-PVA- nanoparticles within chitosan-dextran sulfate nanoparticles (CS-DS) [CS-DS-coated-DOX-loaded -PLGA-PVA-NP] and study the sensitivity against DOX- resistance- breast cancer cells (MCF-7-DOX-R). These CS-DS and PLGA-PVA double coated DOX are spherical, stable, polydispersed and have zeta potential +2.89 mV. MCF-7- DOX-R cells were derived by exposing increasing doses of DOX in MCF-7 cells. These cells were resistance to 500 nM of DOX while parental cells were susceptible at 150 nM. The double coated NP caused more cytotoxicity in cancer and MCF-7-DOX-R cells without affecting the normal cells in comparison to DOX-loaded-PLGA-PVA-NP. These NP enhances the uptake of DOX in MCF-7-DOX-R cells and caused apoptosis by increasing apoptotic nuclei, Bax/Bcl-xL ratio, cleaved product PARP-1, tumor suppressor gene p21, p53, topoisomerase inhibition activity, DNA damage and decreasing the migratory potential of cells. An increased S phase arrest was noted in DOX and DOX- loaded- PLGA-PVA-NP treated cells but reduction of S phase and simultaneous increase of Sub-G1 was observed in double coated-NP. Thus, data revealed that CS-DS- DOX- loaded PLGA-PVA- NP caused DOX-resistance cell death by inducing inhibition of topoisomerase activity followed by DNA damage.

Evaluation of Tumor Treatment of Magnetic Nanoparticles Driven by Extremely Low Frequency Magnetic Field

Recently, magnetic nanoparticles (MNPs), which can be manipulated in the magnetic field, have received much attention in tumor therapy. Extremely low frequency magnetic field (ELMF) system can initiate MNPs vibrating and the movement of MNPs inside of cells can be controlled by adjusting the frequency and intensity of ELMF towards irreversible cell damages. In this study, we investigated the detrimental effects on tumor cells with MNPs under various ELMF exposure conditions. An in-house built ELMF system was developed and utilized for evaluating the treatment efficiency of MNPs on tumor cells with specific intensities (2–20 Hz) and frequencies (0.1–20 mT). Significant morphological changes were found in tumor cells treated with MNPs in combing with ELMF, which were consistent with noticeable decrease in cell viability. With the increase of the intensity and frequency of the magnetic field, the structural integrity of tumor tissue can be further destroyed. Destructive effects of MNPs and ELMF on tumor tissues were further determined by the pathophysiological changes observed in vivo in animal study. Taken together, the combination of MNPs and ELMF had a great potential as an innovative treatment approach for tumor intervention.

Reprogramming Factors Remodel Melanoma Cell Phenotype by Changing Stat3 Expression

The limited availability of melanoma stem cells is a major challenge for therapeutic reagent screening and study of molecular mechanisms. It has been shown that induced expression of four stem cell factors (Oct4, Sox2, Klf4, and c-Myc) changes the phenotype of osteosarcoma and breast cancer cells to osteosarcoma stem cells and breast cancer stem cells, respectively. The present study aimed to explore whether these four factors might change the phenotype of melanoma cells to melanoma stem cells and, if so, to examine the possible molecular signal involved. Melanoma B16-F10 cells were transfected with the plasmid TetO-FUW-OSKM which contains cDNA expressing four factors, driven by the Tet-On element. We found that expression of the four transcription factors was highly induced by DOX in the stable melanoma cell clones. Further studies confirmed that induced expression of these factors remodeled the phenotype of the melanoma cells to melanoma stem cells (MSCs). This conclusion was supported by the evidence that induced expression of these factors increased the numbers of tumor-initiating cells, (namely MSCs), both in an in vitro cell culture system and in a mouse in vivo model. The conclusion was further supported by the observation that the induction of these factors exclusively increased the mRNA of signal transducer and activator of transcription 3 which has been reported to play a crucial role in stem cell maintenance. Thus, phenotypic remodeling of melanoma cells following the induction of these four factors provided a simple and optimal means to constantly obtain MSCs for screening new therapeutic reagents. The result also reveals that Stat3 may be a crucial link between the induction of the four factors and the cell remodeling, suggesting its potential role as a target to fight melanoma.

Anti-cancer activity of camptothecin nanocrystals decorated by silver nanoparticles

CPT/Ag nanocrystals display extreme and broad-spectrum anti-cancer activity and high selectivity through a cooperation effect between CPT and AgNPs.

Ursolic Acid Loaded PLGA Nanoparticles: in vitro and in vivo Evaluation to Explore Tumor Targeting Ability on B16F10 Melanoma Cell Lines

PURPOSE

Ursolic acid (UA), a pentacyclic triterpenoid extracted from plants, shows promising inhibitory effect in different tumor bearing cell lines. In the present study we fabricated UA loaded PLGA nanoparticles (UA-NPs) as the drug carrier and thoroughly evaluated in vitro and in vivo the differential tumor targeting effects of UA and UA-NPs in B16F10 melanoma cells.

METHODS

Ursolic acid loaded PLGA nanoparticles were prepared by emulsion solvent evaporation technique and evaluated for particle size, polydispersity, zeta potential and drug release potency. MTT assay as well as flow cytometric and confocal microscopic analyses were done in B16F10 mouse melanoma cell lines. Formulations were labeled with technetium-99m to evaluate the biodistribution and perform scintigraphic imaging studies following intravenous administration in tumor bearing mice model.

RESULTS

Single emulsification technique produced smooth spherical nanoparticles of small size with relatively narrow size distribution (154 ± 4.56 nm). On B16F10 cell line, the formulation showed higher cytotoxicity compared to the free drug due to increased in vitro cellular uptake. The formulation was successfully radiolabeled and remained substantially (>90%) stable when incubated (37°C, 6 h) separately in normal saline or freshly collected rat serum or histidine solution. The radiolabeled UA-NPs exhibited slower blood clearance and comparatively high uptake in tumor region as evidenced by biodistribution and scintigraphic studies.

CONCLUSIONS

The in vitro and in vivo studies have proved the tumor targeting potential of UA-NPs in B16F10 melanoma cell lines.

SURVIVIN as a marker for quiescent-breast cancer stem cells-An intermediate, adherent, pre-requisite phase of breast cancer metastasis

Cancer stem cells drive the metastatic cascade by undergoing epithelial to mesenchymal transition (EMT) and again mesenchymal to epithelial transition (MET). Using multiple breast cancer cell lines including cigarette smoke induced breast cancer cells and tumor derived primary cells from patient sample; we developed a breast cancer metastasis model and reported the existence of an adherent, distinct pre-metastatic phase, quiescent-breast cancer stem cells (Q-BCSCs) prior to attaining an EMT. SURVIVIN was found to be expressed in Q-BCSCs. Time dependant biphasic expression of SURVIVIN in Q-BCSCs reveals that Q-BCSCs is a pre-metastatic phase distinct from both epithelial and mesenchymal counterparts. SURVIVIN favours metastasis and up-regulates WNT/β-CATENIN pathway in a PI3 K/AKT-dependant manner for self-renewal. Knockdown of SURVIVIN in Q-BCSCs lost the metastatic property of cells by inhibiting invasion, EMT-MET, PI3 K/AKT/WNT cascade, and induced apoptosis. Thus, our data suggest the existence of a novel pre-metastatic phase (Q-BCSCs) before EMT and SURVIVIN acts as a marker for Quiescent-BCSCs.