Transferrin-liposome-mediated systemic p53 gene therapy in combination with radiation results in regression of human head and neck cancer xenografts

SMARCB1 Gene Therapy Using a Novel Tumor-Targeted Nanomedicine Enhances Anti-Cancer Efficacy in a Mouse Model of Atypical Teratoid Rhabdoid Tumors

Purpose

Atypical teratoid rhabdoid tumor (ATRT) is a deadly, fast-growing form of pediatric brain cancer with poor prognosis. Most ATRTs are associated with inactivation of SMARCB1, a subunit of the chromatin remodeling complex, which is involved in developmental processes. The recent identification of SMARCB1 as a tumor suppressor gene suggests that restoration of SMARCB1 could be an effective therapeutic approach.

Methods

We tested SMARCB1 gene therapy in SMARCB1-deficient rhabdoid tumor cells using a novel tumor-targeted nanomedicine (termed scL-SMARCB1) to deliver wild-type SMARCB1. Our nanomedicine is a systemically administered immuno-lipid nanoparticle that can actively cross the blood-brain barrier via transferrin receptor-mediated transcytosis and selectively target tumor cells via transferrin receptor-mediated endocytosis. We studied the antitumor activity of the scL-SMARCB1 nanocomplex either as a single agent or in combination with traditional treatment modalities in preclinical models of SMARCB1-deficient ATRT.

Results

Restoration of SMARCB1 expression by the scL-SMARCB1 nanocomplex blocked proliferation, and induced senescence and apoptosis in ATRT cells. Systemic administration of the scL-SMARCB1 nanocomplex demonstrated antitumor efficacy as monotherapy in mice bearing ATRT xenografts, where the expression of exogenous SMARCB1 modulates MYC-target genes. scL-SMARCB1 demonstrated even greater antitumor efficacy when combined with either cisplatin-based chemotherapy or radiation therapy, resulting in significantly improved survival of ATRT-bearing mice.

Conclusion

Collectively, our data suggest that restoring SMARCB1 function via the scL-SMARCB1 nanocomplex may lead to therapeutic benefits in ATRT patients when combined with traditional chemoradiation therapies.

Moving beyond traditional therapies: the role of nanomedicines in lung cancer

Amidst a global rise in lung cancer occurrences, conventional therapies continue to pose substantial side effects and possess notable toxicities while lacking specificity. Counteracting this, the incorporation of nanomedicines can notably enhance drug delivery at tumor sites, extend a drug's half-life and mitigate inadvertent toxic and adverse impacts on healthy tissues, substantially influencing lung cancer's early detection and targeted therapy. Numerous studies signal that while the nano-characteristics of lung cancer nanomedicines play a pivotal role, further interplay with immune, photothermal, and genetic factors exist. This review posits that the progression towards multimodal combination therapies could potentially establish an efficacious platform for multimodal targeted lung cancer treatments. Current nanomedicines split into active and passive targeting. Active therapies focus on a single target, often with unsatisfactory results. Yet, developing combination systems targeting multiple sites could chart new paths in lung cancer therapy. Conversely, low drug delivery rates limit passive therapies. Utilizing the EPR effect to bind specific ligands on nanoparticles to tumor cell receptors might create a new regime combining active-passive targeting, potentially elevating the nanomedicines' concentration at target sites. This review collates recent advancements through the lens of nanomedicine's attributes for lung cancer therapeutics, the novel carrier classifications, targeted therapeutic modalities and their mechanisms, proposing that the emergence of multi-target nanocomposite therapeutics, combined active-passive targeting therapies and multimodal combined treatments will pioneer novel approaches and tools for future lung cancer clinical therapies.

GOF Mutant p53 in Cancers: A Therapeutic Challenge

Simple Summary

In normal cells, p53 is a protein which regulates the cell cycle progression to ensure normal cell division, growth, and development. However, in cancer, changes in the p53 DNA sequence, called genetic mutation, results in the protein either losing its normal function or exhibiting advanced pro-tumorigenic functions that lead to cancer. Importantly, cancers with mutations in the p53 protein often represent ones which are more aggressive and more resistant to chemotherapy. As a result, many studies have and continue to investigate multiple ways to target mutant p53-bearing cancer using targeted therapy, gene therapy, immunotherapy, and combination therapies. Knowledge of these strategies is important in improving the overall therapeutic response of cancers with mutant p53. This review highlights new strategies and discusses the progression of such therapies.

Abstract

TP53 is mutated in the majority of human cancers. Mutations can lead to loss of p53 expression or expression of mutant versions of the p53 protein. These mutant p53 proteins have oncogenic potential. They can inhibit any remaining WTp53 in a dominant negative manner, or they can acquire new functions that promote tumour growth, invasion, metastasis and chemoresistance. In this review we explore some of the mechanisms that make mutant p53 cells resistant to chemotherapy. As mutant p53 tumours are resistant to many traditional chemotherapies, many have sought to explore new ways of targeting mutant p53 tumours and reinstate chemosensitivity. These approaches include targeting of mutant p53 stability, mutant p53 binding partners and downstream pathways, p53 vaccines, restoration of WTp53 function, and WTp53 gene delivery. The current advances and challenges of these strategies are discussed.

Differential p53-Mediated Cellular Responses to DNA-Damaging Therapeutic Agents

The gene TP53, which encodes the tumor suppressor protein p53, is mutated in about 50% of cancers. In response to cell stressors like DNA damage and after treatment with DNA-damaging therapeutic agents, p53 acts as a transcription factor to activate subsets of target genes which carry out cell fates such as apoptosis, cell cycle arrest, and DNA repair. Target gene selection by p53 is controlled by a complex regulatory network whose response varies across contexts including treatment type, cell type, and tissue type. The molecular basis of target selection across these contexts is not well understood. Knowledge gained from examining p53 regulatory network profiles across different DNA-damaging agents in different cell types and tissue types may inform logical ways to optimally manipulate the network to encourage p53-mediated tumor suppression and anti-tumor immunity in cancer patients. This may be achieved with combination therapies or with p53-reactivating targeted therapies. Here, we review the basics of the p53 regulatory network in the context of differential responses to DNA-damaging agents; discuss recent efforts to characterize differential p53 responses across treatment types, cell types, and tissue types; and examine the relevance of evaluating these responses in the tumor microenvironment. Finally, we address open questions including the potential relevance of alternative p53 transcriptional functions, p53 transcription-independent functions, and p53-independent functions in the response to DNA-damaging therapeutics.

Combining Nanotechnology and Gas Plasma as an Emerging Platform for Cancer Therapy: Mechanism and Therapeutic Implication

Nanomedicine and plasma medicine are innovative and multidisciplinary research fields aiming to employ nanotechnology and gas plasma to improve health-related treatments. Especially cancer treatment has been in the focus of both approaches because clinical response rates with traditional methods that remain improvable for many types of tumor entities. Here, we discuss the recent progress of nanotechnology and gas plasma independently as well as in the concomitant modality of nanoplasma as multimodal platforms with unique capabilities for addressing various therapeutic issues in oncological research. The main features, delivery vehicles, and nexus between reactivity and therapeutic outcomes of nanoparticles and the processes, efficacy, and mechanisms of gas plasma are examined. Especially that the unique feature of gas plasma technology, the local and temporally controlled deposition of a plethora of reactive oxygen, and nitrogen species released simultaneously might be a suitable additive treatment to the use of systemic nanotechnology therapy approaches. Finally, we focus on the convergence of plasma and nanotechnology to provide a suitable strategy that may lead to the required therapeutic outcomes.

A Bibliometric analysis of folate receptor research

BACKGROUND

The objective of this study was to conduct a bibliometric analysis of the entire field of folate receptor research. Folate receptor is expressed on a wide variety of cancers and certain immune cells.

METHODS

A Web of Science search was performed on folate receptor or folate binding protein (1969-to June 28, 2019). The following information was examined: publications per year, overall citations, top 10 authors, top 10 institutions, top 10 cited articles, top 10 countries, co-author collaborations and key areas of research.

RESULTS

In total, 3248 documents for folate receptor or folate binding protein were retrieved for the study years outlined in the methods section search query. The range was 1 per year in 1969 to 264 for the last full year studied (2018). A total of 123,720 citations for the 3248 documents retrieved represented a mean citation rate per article of 38.09 and range of 1667 citations (range 0 to 1667). Researchers in 71 countries authored publications analyzed in this study. The US was the leader in publications and had the highest ranking institution. The top 10 articles have been cited 7270 times during the time frame of this study. The top cited article had an average citation rate of 110 citations per year. Network maps revealed considerable co-authorship among several of the top 10 authors.

CONCLUSION

Our study presents several important insights into the features and impact of folate receptor research. To our knowledge, this is the first bibliometric analysis of folate receptor.

Current Status and Perspectives of Patient-Derived Models for Ewing's Sarcoma

Simple Summary

A paucity of patient-derived cancer models hinders the development of novel therapeutic strategies in Ewing’s sarcoma. This review aimed to demonstrate the utility and possibility of popular patient-derived cancer models by overviewing the reported studies and to encourage the researchers to develop more models for Ewing’s sarcoma.

Abstract

Patient-derived cancer models, including cell lines, organoids, and xenografts, are indispensable tools in cancer research. These models, which recapitulate molecular features of original tumors, allow studies on the biological significance of cancer-associated genes, antitumor effects of novel agents, and molecular mechanisms underlying clinical behaviors of tumors. Moreover, the predictive utility of patient-derived cancer models is expected to facilitate drug development and precision medicine. Ewing’s sarcoma is a highly aggressive mesenchymal tumor with a high metastasis rate. Previous studies demonstrated the utility of cell lines and xenografts in Ewing’s sarcoma research and clinical studies. However, the number of Ewing’s sarcoma models available from public biobanks is limited; this creates an obstacle for research on Ewing’s sarcoma. Novel Ewing’s sarcoma models are needed to establish their utility, further our understanding of the molecular mechanisms, and help develop effective therapeutic strategies. In this review, the current status of patient-derived cancer models is overviewed, and future prospects of model development are discussed from the perspective of Ewing’s sarcoma research. It should be of interest to researchers and clinicians who work on patient-derived cancer models.

Interactions of Vascular Endothelial Growth Factor and p53 with miR-195 in Thyroid Carcinoma: Possible Therapeutic Targets in Aggressive Thyroid Cancers

BACKGROUND

The clinical pathological features, as well as the cellular mechanisms of miR-195, have not been investigated in thyroid carcinoma.

OBJECTIVE

The aim of this study is to identify the interactions of vascular endothelial growth factor (VEGF), p53 and miR-195 in thyroid carcinoma. The clinical and pathological features of miR-195 were also investigated.

METHODS

The expression levels of miR-195 were identified in 123 primary thyroid carcinomas, 40 lymph nodes with metastatic papillary thyroid carcinomas and seven non-neoplastic thyroid tissues (controls) as well as two thyroid carcinoma cell lines, B-CPAP (from metastasizing human papillary thyroid carcinoma) and MB-1 (from anaplastic thyroid carcinoma), by the real-time polymerase chain reaction. Using Western blot and immunofluorescence, the effects of exogenous miR-195 on VEGF-A and p53 protein expression levels were examined. Then, cell cycle and apoptosis assays were performed to evaluate the roles of miR-195 in cell cycle progression and apoptosis.

RESULTS

The expression of miR-195 was downregulated in majority of the papillary thyroid carcinoma tissue as well as in cells. Introduction of exogenous miR-195 resulted in downregulation of VEGF-A and upregulation of p53 protein expressions. Upregulation of miR-195 in thyroid carcinoma cells resulted in cell cycle arrest. Moreover, we demonstrated that miR-195 inhibits cell cycle progression by induction of apoptosis in the thyroid carcinoma cells.

CONCLUSION

Our findings showed for the first time that miR-195 acts as a tumour suppressor and regulates cell cycle progression and apoptosis by targeting VEGF-A and p53 in thyroid carcinoma. The current study exhibited that miR-195 might represent a potential therapeutic target for patients with thyroid carcinomas having aggressive clinical behaviour.

Nanoparticles for Targeting of Prostate Cancer

Prostate cancer (PCa) is the leading cause of death by cancer in men. Because of the drastic decline in the survival rate of PCa patients with advanced/metastatic disease, early diagnosis of disease and therapy without toxic side effects is crucial. Chemotherapy is widely used to control the progression of PCa at the later stages; however, it is associated with off-target toxicities and severe adverse effects due to the lack of specificity. Delivery of therapeutic or diagnostic agents by using targeted nanoparticles is a promising strategy to enhance accuracy and sensitivity of diagnosis of PCa and to increase efficacy and specificity of therapeutic agents. Numerous efforts have been made in past decades to create nanoparticles with different architectural bases for specific delivery payloads to prostate tumors. Major PCa associated cell membrane protein markers identified as targets for such purposes include folate receptor, sigma receptors, transferrin receptor, gastrin-releasing peptide receptor, urokinase plasminogen activator receptor, and prostate specific membrane antigen. Among these markers, prostate specific membrane antigen has emerged as an extremely specific and sensitive targetable marker for designing targeted nanoparticle-based delivery systems for PCa. In this article, we review contemporary advances in design, specificity, and efficacy of nanoparticles functionalized against PCa. Whenever feasible, both diagnostic as well as therapeutic applications are discussed.

Endocytosis in cellular uptake of drug delivery vectors: Molecular aspects in drug development

Drug delivery vectors are widely applied to increase drug efficacy while reducing the side effects and potential toxicity of a drug. They allow for patient-tailored therapy, dose titration, and therapeutic drug monitoring. A major part of drug delivery systems makes use of large nanocarriers: liposomes or virus-like particles (VLPs). These systems allow for a relatively large amount of cargo with good stability of vectors, and they offer multiple options for targeting vectors in vivo. Here we discuss endocytic pathways that are available for drug delivery by large nanocarriers. We focus on molecular aspects of the process, including an overview of potential molecular targets for studies of drug delivery vectors and for future solutions allowing targeted drug delivery.

Bioelectricity for Drug Delivery: The Promise of Cationic Therapeutics

Biological systems overwhelmingly comprise charged entities generating electrical activity that can have significant impact on biological structure and function. This intrinsic bio-electrical activity can also be harnessed for overcoming the tissue matrix and cell membrane barriers, which have been outstanding challenges for targeted drug delivery, by using rationally designed cationic carriers. The weak and reversible long-range electrostatic interactions with fixed negatively charged groups facilitate electro-diffusive transport of cationic therapeutics through full-tissue thickness to effectively reach intra-tissue, cellular, and intracellular target sites. This article presents a perspective on the promise of using rationally designed cationic biomaterials in targeted drug delivery, the underlying charge-based mechanisms, and bio-transport phenomena while addressing outstanding concerns around toxicity and methods to mitigate them. We also discuss electrically charged drugs that are currently being evaluated in clinical trials and identify areas of further development that have the potential to usher in new treatments.

Targeting strategies for superparamagnetic iron oxide nanoparticles in cancer therapy

Among various nanoparticles, superparamagnetic iron oxide nanoparticles (SPIONs) have been increasingly studied for their excellent superparamagnetism, magnetic heating properties, and enhanced magnetic resonance imaging (MRI). The conjugation of SPIONs with drugs to obtain delivery nanosystems has several advantages including magnetic targeted functionalization, in vivo imaging, magnetic thermotherapy, and combined delivery of anticancer agents. To further increase the targeting efficiency of drugs through a delivery nanosystem based on SPIONs, additional targeting moieties including transferrin, antibodies, aptamers, hyaluronic acid, folate, and targeting peptides are coated onto the surface of SPIONs. Therefore, this review summarizes the latest progresses in the conjugation of targeting molecules and drug delivery nanosystems based on SPIONs, especially focusing on their performances to develop efficient targeted drug delivery systems for tumor therapy. STATEMENT OF SIGNIFICANCE: Some magnetic nanoparticle-based nanocarriers loaded with drugs were evaluated in patients and did not produce convincing results, leading to termination of clinical development in phase II/III. An alternative strategy for drug delivery systems based on SPIONs is the conjugation of these systems with targeting segments such as transferrin, antibodies, aptamers, hyaluronic acid, folate, and targeting peptides. These targeting moieties can be recognized by specific integrin/receptors that are overexpressed specifically on the tumor cell surface, resulting in minimizing dosage and reducing off-target effects. This review focuses on magnetic nanoparticle-based nonviral drug delivery systems with targeting moieties to deliver anticancer drugs, with an aim to provide suggestions on the development of SPIONs through discussion.

Targeted nanocomplex carrying siRNA against MALAT1 sensitizes glioblastoma to temozolomide

Intrinsic therapeutic resistance especially in cancer stem cells (CSCs) together with extensive tumor cell infiltration and restricted permeation of the blood-brain barrier (BBB) by drugs may all contribute to the treatment failure in patients with glioblastoma multiforme (GBM). Accumulating evidence suggests that long non-coding RNA (lncRNA), metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) plays a role in tumor cell infiltration and therapeutic resistance of GBM. Using our tumor-targeted nanocomplex, we have modulated the expression of MALAT1 and investigated its impact on GBM cells. Importantly, our nanocomplex is able to target CSCs that are considered to be the prime culprits in therapeutic resistance and recurrence of GBM. Attenuation of MALAT1 by RNA interference significantly lowered the growth, motility and stemness of GBM cells. In addition, silencing of MALAT1 clearly improved the sensitivity of GBM cells to chemotherapeutic agents including the current first-line therapy of GBM [temozolomide (TMZ)]. In animal models of GBM, tumor involution with a modest but statistically significant survival benefit was achieved with concurrent treatment of TMZ and nanocomplex-mediated silencing of MALAT1. These results suggest that combining standard TMZ treatment with lncRNA-targeting therapies using our nanocomplex could substantially enhance the very poor prognosis for GBM patients.

Targeted Delivery to Tumors: Multidirectional Strategies to Improve Treatment Efficiency

Malignant tumors are characterized by structural and molecular peculiarities providing a possibility to directionally deliver antitumor drugs with minimal impact on healthy tissues and reduced side effects. Newly formed blood vessels in malignant lesions exhibit chaotic growth, disordered structure, irregular shape and diameter, protrusions, and blind ends, resulting in immature vasculature; the newly formed lymphatic vessels also have aberrant structure. Structural features of the tumor vasculature determine relatively easy penetration of large molecules as well as nanometer-sized particles through a blood⁻tissue barrier and their accumulation in a tumor tissue. Also, malignant cells have altered molecular profile due to significant changes in tumor cell metabolism at every level from the genome to metabolome. Recently, the tumor interaction with cells of immune system becomes the focus of particular attention, that among others findings resulted in extensive study of cells with preferential tropism to tumor. In this review we summarize the information on the diversity of currently existing approaches to targeted drug delivery to tumor, including (i) passive targeting based on the specific features of tumor vasculature, (ii) active targeting which implies a specific binding of the antitumor agent with its molecular target, and (iii) cell-mediated tumor targeting.

Combination with SGT-53 overcomes tumor resistance to a checkpoint inhibitor

The tumor suppressor p53 responds to genotoxic and oncogenic stresses by inducing cell cycle arrest and apoptosis. Recent studies suggest that p53 also participates in the regulation of cellular immune responses. Here, we have investigated the potential of p53 gene therapy to augment immune checkpoint inhibition by combining an anti-programmed cell death protein 1 (PD1) antibody with SGT-53, our investigational nanomedicine carrying a plasmid encoding human wild-type p53. In three syngeneic mouse tumor models examined including a breast cancer, a non-small cell lung carcinoma, and a glioblastoma, SGT-53 sensitized otherwise refractory tumors to anti-PD1 antibody. The involvement of p53 in enhancing anti-PD1 immunotherapy appears to be multifaceted, since SGT-53 treatment increased tumor immunogenicity, enhanced both innate and adaptive immune responses, and reduced tumor-induced immunosuppression in a 4T1 breast tumor model. In addition, SGT-53 alleviates a fatal xenogeneic hypersensitivity associated with the anti-PD1 antibody in this model. Our data suggest that restoring p53 function by SGT-53 is able to boost anti-tumor immunity to augment anti-PD1 therapy by sensitizing tumors otherwise insensitive to anti-PD1 immunotherapy while reducing immune-related adverse events.

Murine stroma adopts a human-like metabolic phenotype in the PDX model of colorectal cancer and liver metastases

Cancer research is increasingly dependent of patient-derived xenograft model (PDX). However, a major point of concern regarding the PDX model remains the replacement of the human stroma with murine counterpart. In the present work we aimed at clarifying the significance of the human-to-murine stromal replacement for the fidelity of colorectal cancer (CRC) and liver metastasis (CRC-LM) PDX model. We have conducted a comparative metabolic analysis between 6 patient tumors and corresponding PDX across 4 generations. Metabolic signatures of cancer cells and stroma were measured separately by MALDI-imaging, while metabolite changes in entire tumors were quantified using mass spectrometry approach. Measurement of glucose metabolism was also conducted in vivo using [¹⁸F]-fluorodeoxyglucose (FDG) and positron emission tomography (PET). In CRC/CRC-LM PDX model, human stroma was entirely replaced at the second generation. Despite this change, MALDI-imaging demonstrated that the metabolic profiles of both stromal and cancer cells remained stable for at least four generations in comparison to the original patient material. On the tumor level, profiles of 86 water-soluble metabolites as well as 93 lipid mediators underlined the functional stability of the PDX model. In vivo PET measurement of glucose uptake (reflecting tumor glucose metabolism) supported the ex vivo observations. Our data show for the first time that CRC/CRC-LM PDX model maintains the functional stability at the metabolic level despite the early replacement of the human stroma by murine cells. The findings demonstrate that human cancer cells actively educate murine stromal cells during PDX development to adopt the human-like phenotype.

Safety and Efficacy in Advanced Solid Tumors of a Targeted Nanocomplex Carrying the p53 Gene Used in Combination with Docetaxel: A Phase 1b Study

Loss of p53 suppressor function, through mutations or inactivation of the p53 pathway, occurs in most human cancers. SGT-53 is a liposomal nanocomplex designed for systemic, tumor-targeting delivery of the wt p53 gene. In this nanodelivery system, an anti-transferrin receptor single-chain antibody fragment serves as the targeting moiety. In an initial phase 1 trial in patients with advanced solid tumors, SGT-53 demonstrated tumor-specific targeting, was shown to be well tolerated, and was associated with an antitumor effect in several patients. Our preclinical studies have also demonstrated enhanced antitumor activity with the combination of SGT-53 and docetaxel. Thus, this dose-escalation trial was undertaken to assess the combination of SGT-53 and docetaxel for safety and potential efficacy in 14 advanced cancer patients. Results reveal that the combination of SGT-53 (maximum dose, 3.6 mg DNA/infusion) and docetaxel (75 mg/m(2)/infusion) was well tolerated. Moreover, clinical activity involving 12 evaluable patients was observed. Three of these patients achieved RECIST-verified partial responses with tumor reductions of -47%, -51%, and -79%. Two others had stable disease with significant shrinkage (-25% and -16%). These results support phase 2 testing of SGT-53 in combination with docetaxel.

Radiogenic Therapy: Novel Approaches for Enhancing Tumor Radiosensitivity

Radiotherapy (RT) is a well established modality for treating many forms of cancer. However, despite many improvements in treatment planning and delivery, the total radiation dose is often too low for tumor cure, because of the risk of normal tissue damage. Gene therapy provides a new adjunctive strategy to enhance the effectiveness of RT, offering the potential for preferential killing of cancer cells and sparing of normal tissues. This specificity can be achieved at several levels including restricted vector delivery, transcriptional targeting and specificity of the transgene product. This review will focus on those gene therapy strategies that are currently being evaluated in combination with RT, including the use of radiation sensitive promoters to control the timing and location of gene expression specifically within tumors. Therapeutic transgenes chosen for their radiosensitizing properties will also be reviewed, these include:

gene correction therapy, in which normal copies of genes responsible for radiation-induced apoptosis are transfected to compensate for the deletions or mutated variants in tumor cells (p53 is the most widely studied example). enzymes that synergize the radiation effect, by generation of a toxic species from endogenous precursors ( e.g., inducible nitric oxide synthase) or by activation of non toxic prodrugs to toxic species ( e.g., herpes simplex virus thymidine kinase/ganciclovir) within the target tissue. conditionally replicating oncolytic adenoviruses that synergize the radiation effect. membrane transport proteins ( e.g., sodium iodide symporter) to facilitate uptake of cytotoxic radionuclides.

The evidence indicates that many of these approaches are successful for augmenting radiation induced tumor cell killing with clinical trials currently underway.

A Phase l Study of a Tumor-targeted Systemic Nanodelivery System, SGT-94, in Genitourinary Cancers

Gene therapy development has been limited by our inability to target multifocal cancer with systemic delivery. We developed a systemically administered, tumor-targeted liposomal nanodelivery complex (SGT-94) carrying a plasmid encoding RB94, a truncated form of the RB gene. In preclinical studies, RB94 showed marked cytotoxicity against tumor but not normal cells. SGT-94 was administered intravenously in a first-in-man study in metastatic genitourinary cancer. Minimal side effects were observed; dose-limiting toxicity (DLT) has not been reached in 11 evaluable patients. There was evidence of clinical activity at the 2.4 mg dose with one complete remission (CR) and one partial remission (PR). The patient in CR was retreated upon progression and had a second PR. Furthermore, there was tumor-specific targeting of the SGT-94 complex. One patient had wedge resections of two lung metastases which demonstrated RB94 expression at the DNA level by polymerase chain reaction (PCR) and at the protein level by Western blotting, with no RB94 present in normal contiguous lung. In conclusion, systemically delivered SGT-94 showed evidence of selective tumor targeting and was well tolerated with evidence of clinical activity. Additional studies are warranted to explore the activity of this drug as a single agent and in combination therapy.

Curcumin and Resveratrol as Promising Natural Remedies with Nanomedicine Approach for the Effective Treatment of Triple Negative Breast Cancer

Researchers have made considerable progress in last few decades in understanding mechanisms underlying pathogenesis of breast cancer, its phenotypes, its molecular and genetic changes, its physiology, and its prognosis. This has allowed us to identify specific targets and design appropriate chemical entities for effective treatment of most breast cancer phenotypes, resulting in increased patient survivability. Unfortunately, these strategies have been largely ineffective in the treatment of triple negative breast cancer (TNBC). Hormonal receptors lacking render the conventional breast cancer drugs redundant, forcing scientists to identify novel targets for treatment of TNBC. Two natural compounds, curcumin and resveratrol, have been widely reported to have anticancer properties. In vitro and in vivo studies show promising results, though their effectiveness in clinical settings has been less than satisfactory, owing to their feeble pharmacokinetics. Here we discuss these naturally occurring compounds, their mechanism as anticancer agents, their shortcomings in translational research, and possible methodology to improve their pharmacokinetics/pharmacodynamics with advanced drug delivery systems.

How can nanomedicines overcome cellular-based anticancer drug resistance?

This review discusses the mechanisms of anticancer drug resistance according to its cellular level of action and outlines the nanomedicine-based strategies adopted to overcome it.

Nucleic acid targeting: towards personalized therapy for head and neck cancer

In light of a detailed characterization of genetic aberrations in cancer, nucleic acid targeting represents an attractive therapeutic approach with significant translational potential. Head and neck squamous cell carcinoma (HNSCC) is a leading cause of cancer deaths worldwide with stagnant 5-year survival rates. Advances in conventional treatment have done little to improve survival and combined chemoradiation is associated with significant adverse effects. Recent reports have characterized the genetic alterations in HNSCC and demonstrated that mutations confer resistance to conventional and molecular targeted therapies. The ability to use specific nucleic acid sequences to inhibit cancer-associated genes including non-druggable targets facilitates personalized medicine approaches with less adverse effects. Additionally, advances in drug delivery mechanisms have increased the transfection efficiency aiding in greater therapeutic responses. Given these advances, the stage has been set to translate the information garnered from genomic studies into personalized treatment strategies. Genes involved in the tumor protein 53 (TP53) and epidermal growth factor receptor (EGFR) pathways have been extensively investigated and many promising preclinical studies have shown tumor inhibition through genetic modulation. We, and others, have demonstrated that targeting oncogene expression with gene therapy approaches is feasible in patients. Other methods such as RNA interference have proven to be effective and are potential candidates for clinical studies. This review summarizes the major advances in sequence-specific gene modulation in the preclinical setting and in clinical trials in head and neck cancer patients.

Encapsulation of temozolomide in a tumor-targeting nanocomplex enhances anti-cancer efficacy and reduces toxicity in a mouse model of glioblastoma

Although temozolomide (TMZ) is the current first-line chemotherapy for glioblastoma multiforme (GBM), most patients either do not respond or ultimately fail TMZ treatment. Both intrinsic tumor resistance and limited access of TMZ to brain tumors as a result of the blood-brain barrier (BBB) contribute to poor response and ultimately to poor prognosis for GBM patients. We have developed a "dual-targeting" nanomedicine that both actively crosses the BBB and actively targets cancer cells once in the brain parenchyma. This nanomedicine (termed scL-TMZ) is sized ~40 nm and comprised of a cationic liposome (DOTAP:DOPE) encapsulating TMZ. The surface of liposome is decorated with anti-transferrin receptor single-chain antibody fragments to facilitate the crossing of the BBB by the scL-TMZ in addition to targeting GBM in the brain. This novel formulation was found to be markedly more effective than standard TMZ in both TMZ-resistant and TMZ-sensitive GBM. Encapsulation of TMZ also markedly enhanced its efficacy in killing a variety of non-GBM tumor cells. The scL-TMZ nanocomplex was shown to target cancer stem cells, which have been linked to both drug resistance and recurrence in GBM. Most significantly, systemically administered scL-TMZ significantly prolonged survival in mice bearing intracranial GBM tumors. The improved efficacy of scL-TMZ compared to standard TMZ was accompanied by reduced toxicity, so we conclude that the scL-TMZ nanomedicine holds great promise as a more effective therapy for GBM and other tumor types.

Cancer active targeting by nanoparticles: a comprehensive review of literature

PURPOSE

Cancer is one of the leading causes of death, and thus, the scientific community has but great efforts to improve cancer management. Among the major challenges in cancer management is development of agents that can be used for early diagnosis and effective therapy. Conventional cancer management frequently lacks accurate tools for detection of early tumors and has an associated risk of serious side effects of chemotherapeutics. The need to optimize therapeutic ratio as the difference with which a treatment affects cancer cells versus healthy tissues lead to idea that it is needful to have a treatment that could act a the "magic bullet"-recognize cancer cells only. Nanoparticle platforms offer a variety of potentially efficient solutions for development of targeted agents that can be exploited for cancer diagnosis and treatment. There are two ways by which targeting of nanoparticles can be achieved, namely passive and active targeting. Passive targeting allows for the efficient localization of nanoparticles within the tumor microenvironment. Active targeting facilitates the active uptake of nanoparticles by the tumor cells themselves.

METHODS

Relevant English electronic databases and scientifically published original articles and reviews were systematically searched for the purpose of this review.

RESULTS

In this report, we present a comprehensive review of literatures focusing on the active targeting of nanoparticles to cancer cells, including antibody and antibody fragment-based targeting, antigen-based targeting, aptamer-based targeting, as well as ligand-based targeting.

CONCLUSION

To date, the optimum targeting strategy has not yet been announced, each has its own advantages and disadvantages even though a number of them have found their way for clinical application. Perhaps, a combination of strategies can be employed to improve the precision of drug delivery, paving the way for a more effective personalized therapy.

Nanotechnology in bladder cancer: current state of development and clinical practice

Nanotechnology is being developed for the diagnosis and treatment of both nonmyoinvasive bladder cancer (NMIBC) and invasive bladder cancer. The diagnostic applications of nanotechnology in NMIBC mainly focus on tumor identification during endoscopy to increase complete resection of bladder cancer while nanotechnology to capture malignant cells or their components continues to be developed. The therapeutic applications of nanotechnology in NMIBC are to reformulate biological and cytotoxic agents for intravesical instillation, combine both diagnostic and therapeutic application in one nanoformulation. In invasive and advanced bladder cancer, magnetic resonance imaging with supraparamagnetic iron oxide nanoparticles can improve the sensitivity and specificity in detecting small metastasis to lymph nodes. Nanoformulation of cytotoxic agents can potentially decrease the toxicity while increasing efficacy.

A tumor-targeting p53 nanodelivery system limits chemoresistance to temozolomide prolonging survival in a mouse model of glioblastoma multiforme

Development of temozolomide (TMZ) resistance contributes to the poor prognosis for glioblastoma multiforme (GBM) patients. It was previously demonstrated that delivery of exogenous wild-type tumor suppressor gene p53 via a tumor-targeted nanocomplex (SGT-53) which crosses the blood-brain barrier could sensitize highly TMZ-resistant GBM tumors to TMZ. Here we assessed whether SGT-53 could inhibit development of TMZ resistance. SGT-53 significantly chemosensitized TMZ-sensitive human GBM cell lines (U87 and U251), in vitro and in vivo. Furthermore, in an intracranial GBM tumor model, two cycles of concurrent treatment with systemically administered SGT-53 and TMZ inhibited tumor growth, increased apoptosis and most importantly, significantly prolonged median survival. In contrast TMZ alone had no significant effect on median survival compared to a single cycle of TMZ. These results suggest that combining SGT-53 with TMZ appears to limit development of TMZ resistance, prolonging its anti-tumor effect and could be a more effective therapy for GBM.

FROM THE CLINICAL EDITOR

Using human glioblastoma multiforma cell lines, this research team demonstrated that the delivery of exogenous wild-type tumor suppressor gene p53 via a tumor-targeted nanocomplex limited the development of temozolomide resistance and prolonged its anti-tumor effect, which may enable future human application of this or similar techniques.

A nanoparticle carrying the p53 gene targets tumors including cancer stem cells, sensitizes glioblastoma to chemotherapy and improves survival

Temozolomide (TMZ)-resistance in glioblastoma multiforme (GBM) has been linked to upregulation of O(6)-methylguanine-DNA methyltransferase (MGMT). Wild-type (wt) p53 was previously shown to down-modulate MGMT. However, p53 therapy for GBM is limited by lack of efficient delivery across the blood brain barrier (BBB). We have developed a systemic nanodelivery platform (scL) for tumor-specific targeting (primary and metastatic), which is currently in multiple clinical trials. This self-assembling nanocomplex is formed by simple mixing of the components in a defined order and a specific ratio. Here, we demonstrate that scL crosses the BBB and efficiently targets GBM, as well as cancer stem cells (CSCs), which have been implicated in recurrence and treatment resistance in many human cancers. Moreover, systemic delivery of scL-p53 down-modulates MGMT and induces apoptosis in intracranial GBM xenografts. The combination of scL-p53 and TMZ increased the antitumor efficacy of TMZ with enhanced survival benefit in a mouse model of highly TMZ-resistant GBM. scL-p53 also sensitized both CSCs and bulk tumor cells to TMZ, increasing apoptosis. These results suggest that combining scL-p53 with standard TMZ treatment could be a more effective therapy for GBM.

Nanomedicine for drug targeting: strategies beyond the enhanced permeability and retention effect

The growing research interest in nanomedicine for the treatment of cancer and inflammatory-related pathologies is yielding encouraging results. Unfortunately, enthusiasm is tempered by the limited specificity of the enhanced permeability and retention effect. Factors such as lack of cellular specificity, low vascular density, and early release of active agents prior to reaching their target contribute to the limitations of the enhanced permeability and retention effect. However, improved nanomedicine designs are creating opportunities to overcome these problems. In this review, we present examples of the advances made in this field and endeavor to highlight the potential of these emerging technologies to improve targeting of nanomedicine to specific pathological cells and tissues.

Nanopreparations to overcome multidrug resistance in cancer

Multidrug resistance is the most widely exploited phenomenon by which cancer eludes chemotherapy. Broad variety of factors, ranging from the cellular ones, such as over-expression of efflux transporters, defective apoptotic machineries, and altered molecular targets, to the physiological factors such as higher interstitial fluid pressure, low extracellular pH, and formation of irregular tumor vasculature are responsible for multidrug resistance. A combination of various undesirable factors associated with biological surroundings together with poor solubility and instability of many potential therapeutic small & large molecules within the biological systems and systemic toxicity of chemotherapeutic agents has necessitated the need for nano-preparations to optimize drug delivery. The physiology of solid tumors presents numerous challenges for successful therapy. However, it also offers unique opportunities for the use of nanotechnology. Nanoparticles, up to 400 nm in size, have shown great promise for carrying, protecting and delivering potential therapeutic molecules with diverse physiological properties. In this review, various factors responsible for the MDR and the use of nanotechnology to overcome the MDR, the use of spheroid culture as well as the current technique of producing microtumor tissues in vitro are discussed in detail.

The clinical potential of targeted nanomedicine: delivering to cancer stem-like cells

Cancer stem-like cells (CSCs) have been implicated in recurrence and treatment resistance in many human cancers. Thus, a CSC-targeted drug delivery strategy to eliminate CSCs is a desirable approach for developing a more effective anticancer therapy. We have developed a tumor-targeting nanodelivery platform (scL) for systemic administration of molecular medicines. Following treatment with the scL nanocomplex carrying various payloads, we have observed exquisite tumor-targeting specificity and significant antitumor response with long-term survival benefit in numerous animal models. We hypothesized that this observed efficacy might be attributed, at least in part, to elimination of CSCs. Here, we demonstrate the ability of scL to target both CSCs and differentiated nonstem cancer cells (non-CSCs) in various mouse models including subcutaneous and intracranial xenografts, syngeneic, and chemically induced tumors. We also show that systemic administration of scL carrying the wtp53 gene was able to induce tumor growth inhibition and the death of both CSCs and non-CSCs in subcutaneous colorectal cancer xenografts suggesting that this could be an effective method to reduce cancer recurrence and treatment resistance. This scL nanocomplex is being evaluated in a number of clinical trials where it has been shown to be well tolerated with indications of anticancer activity.

Delivery of therapeutic nucleic acids via transferrin and transferrin receptors: lipoplexes and other carriers

INTRODUCTION

The overexpression of transferrin (Tf) receptors on cancer cells renders them a useful target for the delivery of small-molecule drugs and nucleic acid therapeutics to these cells. This approach could alleviate the non-target effects of the drugs.

AREAS COVERED

The function of the Tf receptor, the development of Tf-lipid-DNA complexes (Tf lipoplexes), therapeutic use of lipoplexes and polymer-DNA complexes (poylplexes), and the therapeutic use of Tf-lipoplexes and anti-Tf-receptor antibody-lipoplexes are outlined. The literature search for this review was based primarily on the terms 'lipoplexes,' 'lipopolyplexes' 'transferrin,' 'transferrin receptor,' and 'gene therapy.' However, the review was not intended to be comprehensive.

EXPERT OPINION

Complexes of Tf with cationic liposomes and nucleic acids, or liposomes with covalently attached Tf or anti-transferrin receptor antibodies have been used for the delivery of therapeutic genes, antisense oligodeoxynucleotides, and short interfering RNA. Although such targeted nonviral delivery vehicles may benefit from further enhancement of their efficacy, current achievements at the cell culture and animal model level should be translated into clinical applications, restricted initially to localized delivery into accessible tissues to avoid potential systemic side-effects and non-target delivery.

Perspectives of nanotechnology in minimally invasive therapy of breast cancer

Breast cancer, the most common type of cancer among women in the western world, affects approximately one out of every eight women over their lifetime. In recognition of the high invasiveness of surgical excision and severe side effects of chemical and radiation therapies, increasing efforts are made to seek minimally invasive modalities with fewer side effects. Nanoparticles (<100 nm in size) have shown promising capabilities for delivering targeted therapeutic drugs to cancer cells and confining the treatment mainly within tumors. Additionally, some nanoparticles exhibit distinct properties, such as conversion of photonic energy into heat, and these properties enable eradication of cancer cells. In this review, current utilization of nanostructures for cancer therapy, especially in minimally invasive therapy, is summarized with a particular interest in breast cancer.

The changing face of vascular interventional radiology: the future role of pharmacotherapies and molecular imaging

Interventional radiology has had to evolve constantly because there is the ever-present competition and threat from other specialties within medicine, surgery, and research. The development of new technologies, techniques, and therapies is vital to broaden the horizon of interventional radiology and to ensure its continued success in the future. In part, this change will be due to improved chronic disease prevention altering what we treat and in whom. The most important of these strategies are the therapeutic use of statins, Beta-blockers, angiotensin-converting enzyme inhibitors, and substances that interfere with mast cell degeneration. Molecular imaging and therapeutic strategies will move away from conventional techniques and nano and microparticle molecular technology, tissue factor imaging, gene therapy, endothelial progenitor cells, and photodynamic therapy will become an important part of interventional radiology of the future. This review looks at these new and exciting technologies.

Phase I study of a systemically delivered p53 nanoparticle in advanced solid tumors

Selective delivery of therapeutic molecules to primary and metastatic tumors is optimal for effective cancer therapy. A liposomal nanodelivery complex (scL) for systemic, tumor-targeting delivery of anticancer therapeutics has been developed. scL employs an anti-transferrin receptor (TfR), scFv as the targeting molecule. Loss of p53 suppressor function, through mutations or inactivation of the p53 pathway, is present in most human cancers. Rather than being transiently permissive for tumor initiation, persistence of p53 dysfunction is a continuing requirement for maintaining tumor growth. Herein, we report results of a first-in-man Phase I clinical trial of restoration of the normal human tumor suppressor gene p53 using the scL nanocomplex (SGT-53). Minimal side effects were observed in this trial in patients with advanced solid tumors. Furthermore, the majority of patients demonstrated stable disease. One patient with adenoid cystic carcinoma had his status changed from unresectable to resectable after one treatment cycle. More significantly, we observed an accumulation of the transgene in metastatic tumors, but not in normal skin tissue, in a dose-related manner. These results show not only that systemically delivered SGT-53 is well tolerated and exhibits anticancer activity, but also supply evidence of targeted tumor delivery of SGT-53 to metastatic lesions.

A systematic analysis of peptide linker length and liposomal polyethylene glycol coating on cellular uptake of peptide-targeted liposomes

PEGylated liposomes are attractive pharmaceutical nanocarriers; however, literature reports of ligand-targeted nanoparticles have not consistently shown successful results. Here, we employed a multifaceted synthetic strategy to prepare peptide-targeted liposomal nanoparticles with high purity, reproducibility, and precisely controlled stoichiometry of functionalities to evaluate the role of liposomal PEG coating, peptide EG-linker length, and peptide valency on cellular uptake in a systematic manner. We analyzed these parameters in two distinct disease models where the liposomes were functionalized with either HER2- or VLA-4-antagonistic peptides to target HER2-overexpressing breast cancer cells or VLA-4-overexpressing myeloma cells, respectively. When targeting peptides were tethered to nanoparticles with an EG45 (∼PEG2000) linker in a manner similar to a more traditional formulation, their cellular uptake was not enhanced compared to non-targeted versions regardless of the liposomal PEG coating used. Conversely, reduction of the liposomal PEG to PEG350 and the peptide linker to EG12 dramatically enhanced cellular uptake by ∼9 fold and ∼100 fold in the breast cancer and multiple myeloma cells, respectively. Uptake efficiency reached a maximum and a plateau with ∼2% peptide density in both disease models. Taken together, these results demonstrate the significance of using the right design elements such as the appropriate peptide EG-linker length in coordination with the appropriate liposomal PEG coating and optimal ligand density in efficient cellular uptake of liposomal nanoparticles.

Enhanced therapeutic efficacy of iRGD-conjugated crosslinked multilayer liposomes for drug delivery

Targeting nanoparticles by conjugating various specific ligands has shown potential therapeutic efficacy in nanomedicine. However, poor penetration of antitumor drugs into solid tumors remains a major obstacle. Here, we describe a targeting strategy for antitumor drug delivery by conjugating a crosslinked multilamellar liposomal vesicle (cMLV) formulation with a tumor-penetrating peptide, iRGD. The results showed that iRGD peptides could facilitate the binding and cellular uptake of drug-loaded cMLVs and consequently enhance the antitumor efficacy in breast tumor cells, including multidrug-resistant cells. Moreover, colocalization data revealed that iRGD-conjugated cMLVs (iRGD-cMLVs) entered cells via the clathrin-mediated pathway, followed by endosome-lysosome transport for efficient drug delivery. Finally, in vivo study indicated that iRGD-cMLVs could deliver anticancer drugs efficiently to mediate significant tumor suppression.

Transferrin receptor targeting nanomedicine delivering wild-type p53 gene sensitizes pancreatic cancer to gemcitabine therapy

To overcome gene therapy barriers such as low transfection efficiency and nonspecific delivery, liposomal nanoparticles targeted by a single-chain antibody fragment to the transferrin receptor (TfRscFv) delivering wild-type (wt) human p53 (SGT-53) were developed for tumor-specific targeting. We hypothesize that SGT-53 in combination with gemcitabine will demonstrate enhanced therapeutic benefit in an in vivo metastatic pancreatic cancer model. Intrasplenic injection of 1 × 10(6) Panc02 murine pancreatic cancer cells was used to generate in vivo hepatic metastatic tumors. Nanoparticle localization was assessed by tail vein injection of TfRscFv with fluorescently labeled oligonucleotides (6-carboxyfluorescein phosphoramidite (6FAM) ODN) imaged by Xenogen IVIS 200 scan. SGT-53 (equivalent to 30 μg of p53 intravenously) and gemcitabine (20 mg/kg intraperitoneally) alone and in combination were administered biweekly and compared with untreated mice. Survival was determined by blinded daily assessment of morbidity. Human wtp53 expression and transferrin levels in the tumors were assessed by western blot analysis. Tumor burden was quantified by liver weight. Xenogen imaging demonstrated tumor-specific uptake of TfRscFv-6FAM ODN. Exogenous human wtp53 protein was detected in the SGT-53-treated tumors compared with control. Compared with untreated mice with metastatic tumors demonstrating median survival of 20 days, SGT-53, gemcitabine and the combination demonstrated improved median survival of 29, 30 and 37 days, respectively. The combination treatment prolonged median survival when compared with single drug treatment and decreased tumor burden. The tumor targeting liposomal-based SGT-53 nanoparticle is capable of sensitizing pancreatic cancer to conventional chemotherapy in pancreatic cancer models. This approach has the potential to be translated into a new, more effective therapy for pancreatic cancer. Further optimization is ongoing, moving towards a Phase 1B/2 clinical trial.

Chapter seven--Cancer treatment with gene therapy and radiation therapy

Radiation therapy methods have evolved remarkably in recent years which have resulted in more effective local tumor control with negligible toxicity of surrounding normal tissues. However, local recurrence and distant metastasis often occur following radiation therapy mostly due to the development of radioresistance through the deregulation of the cell cycle, apoptosis, and inhibition of DNA damage repair mechanisms. Over the last decade, extensive progress in radiotherapy and gene therapy combinatorial approaches has been achieved to overcome resistance of tumor cells to radiation. In this review, we summarize the results from experimental cancer therapy studies on the combination of radiation therapy and gene therapy.

Viral and nonviral delivery systems for gene delivery

Gene therapy is the process of introducing foreign genomic materials into host cells to elicit a therapeutic benefit. Although initially the main focus of gene therapy was on special genetic disorders, now diverse diseases with different patterns of inheritance and acquired diseases are targets of gene therapy. There are 2 major categories of gene therapy, including germline gene therapy and somatic gene therapy. Although germline gene therapy may have great potential, because it is currently ethically forbidden, it cannot be used; however, to date human gene therapy has been limited to somatic cells. Although numerous viral and nonviral gene delivery systems have been developed in the last 3 decades, no delivery system has been designed that can be applied in gene therapy of all kinds of cell types in vitro and in vivo with no limitation and side effects. In this review we explain about the history of gene therapy, all types of gene delivery systems for germline (nuclei, egg cells, embryonic stem cells, pronuclear, microinjection, sperm cells) and somatic cells by viral [retroviral, adenoviral, adeno association, helper-dependent adenoviral systems, hybrid adenoviral systems, herpes simplex, pox virus, lentivirus, Epstein-Barr virus)] and nonviral systems (physical: Naked DNA, DNA bombardant, electroporation, hydrodynamic, ultrasound, magnetofection) and (chemical: Cationic lipids, different cationic polymers, lipid polymers). In addition to the above-mentioned, advantages, disadvantages, and practical use of each system are discussed.

Multifunctional targeting micelle nanocarriers with both imaging and therapeutic potential for bladder cancer

Background

We previously developed a bladder cancer-specific ligand (PLZ4) that can specifically bind to both human and dog bladder cancer cells in vitro and in vivo. We have also developed a micelle nanocarrier drug-delivery system. Here, we assessed whether the targeting micelles decorated with PLZ4 on the surface could specifically target dog bladder cancer cells.

Materials and methods

Micelle-building monomers (ie, telodendrimers) were synthesized through conjugation of polyethylene glycol with a cholic acid cluster at one end and PLZ4 at the other, which then self-assembled in an aqueous solution to form micelles. Dog bladder cancer cell lines were used for in vitro and in vivo drug delivery studies.

Results

Compared to nontargeting micelles, targeting PLZ4 micelles (23.2 ± 8.1 nm in diameter) loaded with the imaging agent DiD and the chemotherapeutic drug paclitaxel or daunorubicin were more efficient in targeted drug delivery and more effective in cell killing in vitro. PLZ4 facilitated the uptake of micelles together with the cargo load into the target cells. We also developed an orthotopic invasive dog bladder cancer xenograft model in mice. In vivo studies with this model showed the targeting micelles were more efficient in targeted drug delivery than the free dye (14.3×; P < 0.01) and nontargeting micelles (1.5×; P < 0.05).

Conclusion

Targeting micelles decorated with PLZ4 can selectively target dog bladder cancer cells and potentially be developed as imaging and therapeutic agents in a clinical setting. Preclinical studies of targeting micelles can be performed in dogs with spontaneous bladder cancer before proceeding with studies using human patients.

Feasibility and effect of ultrasound microbubble-mediated wild-type p53 gene transfection of HeLa cells

Gene therapy holds great promise for the treatment of diseases. The key problem of gene therapy is the choice of an effective vector. Ultrasound-mediated microbubble technique (UMMT) has already shown promising applications in numerous types of tumors apart from cervical carcinoma. In the present study, according to the results of an MTT assay, we initially chose an ultrasound intensity of 0.5 W/cm(2), an ultrasound exposure time of 30 sec and a microbubble concentration of 10% as the optimum experimental condition for wtp53 plasmid transfection into HeLa cells. To further investigate the transfection efficiency of ultrasound combined with microbubbles, RT-PCR analysis was used to examine the mRNA level of p53. The transfection efficiency in the plasmid plus microbubbles and ultrasound group was significantly higher than that of the other groups. Following transfection of the wtp53 gene, flow cytometric analysis showed that the cell cycle of HeLa cells was arrested in the G1 phase. The results of the present study suggest that UMMT, a new gene delivery system, increases the transfection efficiency of the wtp53 gene. Moreover, the growth of HeLa cells was arrested by introducing wtp53. This study may afford a new trend for the gene therapy of cervical carcinoma.

Liposomal formulations of Etoposide and Docetaxel for p53 mediated enhanced cytotoxicity in lung cancer cell lines

The objective of present investigation was to develop and assess comparative enhancement in cytotoxicity of liposomal Etoposide and Docetaxel in non-small cell lung cancer cell lines after pre-treatment and co-administration of p53 tumor suppressor gene and to assess direct lung targeting of optimized formulations by dry powder inhaler technology. Cationic liposomes with and without drug were prepared and allowed to form p53-lipoplex for undertaking cytotoxicity studies in H-1299 (p53 null) and A-549 (p53 wt) cell lines. The optimized lipoplexes showed average size of 200-350 nm, zeta potential of 25-32 mV and sustained drug release up to 16-24 h. The developed liposomes and lipoplexes showed significant intracellular uptake and demonstrated enhanced cytotoxicity of 13-28 % after p53-drug co-administration and 41-63 % after p53 pre-treatment. The p53 mediated enhanced cytotoxicity by increased apoptosis and necrosis was also confirmed using Annexin V - FITC assay. The increased apoptosis suggested restored p53 function and reduced anti-apoptotic drug resistance theirby causing cell sensitization and synergism towards cytotoxicity. The studies conducted above demonstrated significant cell chemo-sensitization after p53 pre-treatment followed by Etoposide/Docetaxel liposomes administration than p53-Etoposide or p53-Docetaxel lipoplex co-administration; more significantly in Docetaxel and in H 1299 cell line. All the formulations when developed as dry powder inhalers showed significant in vitro lung deposition pattern in cascade impactor with fine particle faction of 33-37%. The study opens up a new strategy to treat lung cancer especially in cases of drug resistance. Moreover direct delivery to lung may provide an important role in complete remission of the disease due to target specificity.