Minicells: Versatile vectors for targeted drug or si/shRNA cancer therapy

MicroRNAs targeted mTOR as therapeutic agents to improve radiotherapy outcome

MicroRNAs (miRNAs) are small RNA molecules that regulate genes and are involved in various biological processes, including cancer development. Researchers have been exploring the potential of miRNAs as therapeutic agents in cancer treatment. Specifically, targeting the mammalian target of the rapamycin (mTOR) pathway with miRNAs has shown promise in improving the effectiveness of radiotherapy (RT), a common cancer treatment. This review provides an overview of the current understanding of miRNAs targeting mTOR as therapeutic agents to enhance RT outcomes in cancer patients. It emphasizes the importance of understanding the specific miRNAs that target mTOR and their impact on radiosensitivity for personalized cancer treatment approaches. The review also discusses the role of mTOR in cell homeostasis, cell proliferation, and immune response, as well as its association with oncogenesis. It highlights the different ways in which miRNAs can potentially affect the mTOR pathway and their implications in immune-related diseases. Preclinical findings suggest that combining mTOR modulators with RT can inhibit tumor growth through anti-angiogenic and anti-vascular effects, but further research and clinical trials are needed to validate the efficacy and safety of using miRNAs targeting mTOR as therapeutic agents in combination with RT. Overall, this review provides a comprehensive understanding of the potential of miRNAs targeting mTOR to enhance RT efficacy in cancer treatment and emphasizes the need for further research to translate these findings into improved clinical outcomes.

Bacteria-Based Nanoprobes for Cancer Therapy

Surgical removal together with chemotherapy and radiotherapy has used to be the pillars of cancer treatment. Although these traditional methods are still considered as the first-line or standard treatments, non-operative situation, systemic toxicity or resistance severely weakened the therapeutic effect. More recently, synthetic biological nanocarriers elicited substantial interest and exhibited promising potential for combating cancer. In particular, bacteria and their derivatives are omnipotent to realize intrinsic tumor targeting and inhibit tumor growth with anti-cancer agents secreted and immune response. They are frequently employed in synergistic bacteria-mediated anticancer treatments to strengthen the effectiveness of anti-cancer treatment. In this review, we elaborate on the development, mechanism and advantage of bacterial therapy against cancer and then systematically introduce the bacteria-based nanoprobes against cancer and the recent achievements in synergistic treatment strategies and clinical trials. We also discuss the advantages as well as the limitations of these bacteria-based nanoprobes, especially the questions that hinder their application in human, exhibiting this novel anti-cancer endeavor comprehensively.

Deciphering signaling pathway interplay via miRNAs in malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a highly invasive form of lung cancer that adversely affects the pleural and other linings of the lungs. MPM is a very aggressive tumor that often has an advanced stage at diagnosis and a bad prognosis (between 7 and 12 months). When people who have been exposed to asbestos experience pleural effusion and pain that is not explained, MPM should be suspected. After being diagnosed, most MPM patients have a one- to four-year life expectancy. The life expectancy is approximately six months without treatment. Despite the plethora of current molecular investigations, a definitive universal molecular signature has yet to be discovered as the causative factor for the pathogenesis of MPM. MicroRNAs (miRNAs) are known to play a crucial role in the regulation of gene expression at the posttranscriptional level. The association between the expression of these short, non-coding RNAs and several neoplasms, including MPM, has been observed. Although the incidence of MPM is very low, there has been a significant increase in research focused on miRNAs in the past few years. In addition, miRNAs have been found to have a role in various regulatory signaling pathways associated with MPM, such as the Notch signaling network, Wnt/β-catenin, mutation of KRAS, JAK/STAT signaling circuit, protein kinase B (AKT), and Hedgehog signaling pathway. This study provides a comprehensive overview of the existing understanding of the roles of miRNAs in the underlying mechanisms of pathogenic symptoms in MPM, highlighting their potential as viable targets for therapeutic interventions.

Ligand-displaying Escherichia coli cells and minicells for programmable delivery of toxic payloads via type IV secretion systems

IMPORTANCE

The rapid emergence of drug-resistant bacteria and current low rate of antibiotic discovery emphasize the urgent need for alternative antibacterial strategies. We engineered Escherichia coli to conjugatively transfer plasmids to specific E. coli and Pseudomonas aeruginosa recipient cells through the surface display of cognate nanobody/antigen (Nb/Ag) pairs. We further engineered mobilizable plasmids to carry CRISPR/Cas9 systems (pCrispr) for the selective killing of recipient cells harboring CRISPR/Cas9 target sequences. In the assembled programmed delivery system (PDS), Nb-displaying E. coli donors with different conjugation systems and mobilizable pCrispr plasmids suppressed the growth of Ag-displaying recipient cells to significantly greater extents than unpaired recipients. We also showed that anucleate minicells armed with conjugation machines and pCrispr plasmids were highly effective in killing E. coli recipients. Together, our findings suggest that bacteria or minicells armed with PDSs may prove highly effective as an adjunct or alternative to antibiotics for antimicrobial intervention.

Ligand-Displaying E. coli Cells and Minicells for Programmable Delivery of Toxic Payloads via Type IV Secretion Systems

Bacterial type IV secretion systems (T4SSs) are highly versatile macromolecular translocators and offer great potential for deployment as delivery systems for therapeutic intervention. One major T4SS subfamily, the conjugation machines, are well-adapted for delivery of DNA cargoes of interest to other bacteria or eukaryotic cells, but generally exhibit modest transfer frequencies and lack specificity for target cells. Here, we tested the efficacy of a surface-displayed nanobody/antigen (Nb/Ag) pairing system to enhance the conjugative transfer of IncN (pKM101), IncF (F/pOX38), or IncP (RP4) plasmids, or of mobilizable plasmids including those encoding CRISPR/Cas9 systems (pCrispr), to targeted recipient cells. Escherichia coli donors displaying Nb's transferred plasmids to E. coli and Pseudomonas aeruginosa recipients displaying the cognate Ag's at significantly higher frequencies than to recipients lacking Ag's. Nb/Ag pairing functionally substituted for the surface adhesin activities of F-encoded TraN and pKM101-encoded Pep, although not conjugative pili or VirB5-like adhesins. Nb/Ag pairing further elevated the killing effects accompanying delivery of pCrispr plasmids to E. coli and P. aeruginosa transconjugants bearing CRISPR/Cas9 target sequences. Finally, we determined that anucleate E. coli minicells, which are clinically safer delivery vectors than intact cells, transferred self-transmissible and mobilizable plasmids to E. coli and P. aeruginosa cells. Minicell-mediated mobilization of pCrispr plasmids to E. coli recipients elicited significant killing of transconjugants, although Nb/Ag pairing did not enhance conjugation frequencies or killing. Together, our findings establish the potential for deployment of bacteria or minicells as Programmed Delivery Systems (PDSs) for suppression of targeted bacterial species in infection settings.

IMPORTANCE

The rapid emergence of drug-resistant bacteria and current low rate of antibiotic discovery emphasize an urgent need for alternative antibacterial strategies. We engineered Escherichia coli to conjugatively transfer plasmids to specific E. coli and Pseudomonas aeruginosa recipient cells through surface display of cognate nanobody/antigen (Nb/Ag) pairs. We further engineered mobilizable plasmids to carry CRISPR/Cas9 systems (pCrispr) for selective killing of recipient cells harboring CRISPR/Cas9 target sequences. In the assembled Programmed Delivery System (PDS), Nb-displaying E. coli donors with different conjugation systems and mobilizable pCrispr plasmids suppressed growth of Ag-displaying recipient cells to significantly greater extents than unpaired recipients. We also showed that anucleate minicells armed with conjugation machines and pCrispr plasmids were highly effective in killing of E. coli recipients. Together, our findings suggest that bacteria or minicells armed with PDSs may prove highly effective as an adjunct or alternative to antibiotics for antimicrobial intervention.

Epidrugs in the Therapy of Central Nervous System Disorders: A Way to Drive on?

The polygenic nature of neurological and psychiatric syndromes and the significant impact of environmental factors on the underlying developmental, homeostatic, and neuroplastic mechanisms suggest that an efficient therapy for these disorders should be a complex one. Pharmacological interventions with drugs selectively influencing the epigenetic landscape (epidrugs) allow one to hit multiple targets, therefore, assumably addressing a wide spectrum of genetic and environmental mechanisms of central nervous system (CNS) disorders. The aim of this review is to understand what fundamental pathological mechanisms would be optimal to target with epidrugs in the treatment of neurological or psychiatric complications. To date, the use of histone deacetylases and DNA methyltransferase inhibitors (HDACis and DNMTis) in the clinic is focused on the treatment of neoplasms (mainly of a glial origin) and is based on the cytostatic and cytotoxic actions of these compounds. Preclinical data show that besides this activity, inhibitors of histone deacetylases, DNA methyltransferases, bromodomains, and ten-eleven translocation (TET) proteins impact the expression of neuroimmune inflammation mediators (cytokines and pro-apoptotic factors), neurotrophins (brain-derived neurotropic factor (BDNF) and nerve growth factor (NGF)), ion channels, ionotropic receptors, as well as pathoproteins (β-amyloid, tau protein, and α-synuclein). Based on this profile of activities, epidrugs may be favorable as a treatment for neurodegenerative diseases. For the treatment of neurodevelopmental disorders, drug addiction, as well as anxiety disorders, depression, schizophrenia, and epilepsy, contemporary epidrugs still require further development concerning a tuning of pharmacological effects, reduction in toxicity, and development of efficient treatment protocols. A promising strategy to further clarify the potential targets of epidrugs as therapeutic means to cure neurological and psychiatric syndromes is the profiling of the epigenetic mechanisms, which have evolved upon actions of complex physiological lifestyle factors, such as diet and physical exercise, and which are effective in the management of neurodegenerative diseases and dementia.

Chemically engineering cells for precision medicine

Cell-based therapy holds great potential to address unmet medical needs and revolutionize the healthcare industry, as demonstrated by several therapeutics such as CAR-T cell therapy and stem cell transplantation that have achieved great success clinically. Nevertheless, natural cells are often restricted by their unsatisfactory in vivo trafficking and lack of therapeutic payloads. Chemical engineering offers a cost-effective, easy-to-implement engineering tool that allows for strengthening the inherent favorable features of cells and confers them new functionalities. Moreover, in accordance with the trend of precision medicine, leveraging chemical engineering tools to tailor cells to accommodate patients individual needs has become important for the development of cell-based treatment modalities. This review presents a comprehensive summary of the currently available chemically engineered tools, introduces their application in advanced diagnosis and precision therapy, and discusses the current challenges and future opportunities.

Bacteria-based bioactive materials for cancer imaging and therapy

Owing to the unique biological functions, bacteria as biological materials have been widely used in biomedical field. With advances in biotechnology and nanotechnology, various bacteria-based bioactive materials were developed for cancer imaging and therapy. In this review, different types of bacteria-based bioactive materials and their construction strategies were summarized. The advantages and property-function relationship of bacteria-based bioactive materials were described. Representative researches of bacteria-based bioactive materials in cancer imaging and therapy were illustrated, revealing general ideas for their construction. Also, limitation and challenges of bacteria-based bioactive materials in cancer research were discussed.

Harnessing Engineered Immune Cells and Bacteria as Drug Carriers for Cancer Immunotherapy

Immunotherapy continues to be in the spotlight of oncology therapy research in the past few years and has been proven to be a promising option to modulate one's innate and adaptive immune systems for cancer treatment. However, the poor delivery efficiency of immune agents, potential off-target toxicity, and nonimmunogenic tumors significantly limit its effectiveness and extensive application. Recently, emerging biomaterial-based drug carriers, including but not limited to immune cells and bacteria, are expected to be potential candidates to break the dilemma of immunotherapy, with their excellent natures of intrinsic tumor tropism and immunomodulatory activity. More than that, the tiny vesicles and physiological components derived from them have similar functions with their source cells due to the inheritance of various surface signal molecules and proteins. Herein, we presented representative examples about the latest advances of biomaterial-based delivery systems employed in cancer immunotherapy, including immune cells, bacteria, and their derivatives. Simultaneously, opportunities and challenges of immune cells and bacteria-based carriers are discussed to provide reference for their future application in cancer immunotherapy.

Advances of bacteria-based delivery systems for modulating tumor microenvironment

The components and hospitable properties of tumor microenvironment (TME) are associated with tumor progression. Recently, TME modulating vectors and strategies have garnished significant attention in cancer therapy. Although a pilot work has reviewed TME regulation via nanoparticle-based delivery systems, there is no systematical review that summarizes the natural bacteria-based anti-tumor system to modulate TME. In this review, we conclude the strategies of bacterial carriers (including whole bacteria, bacterial skeleton and bacterial components) to regulate TME from the perspective of TME components and hospitable properties, and the clinical trials of bacteria-mediated cancer therapy. Current challenges and future prospects for the design of bacteria-based carriers are also proposed that provide critical insights into this natural delivery system and related translation from the bench to the clinic.

The Landscape of Nanovectors for Modulation in Cancer Immunotherapy

Immunotherapy represents a promising strategy for the treatment of cancer, which functions via the reprogramming and activation of antitumor immunity. However, adverse events resulting from immunotherapy that are related to the low specificity of tumor cell-targeting represent a limitation of immunotherapy's efficacy. The potential of nanotechnologies is represented by the possibilities of immunotherapeutical agents being carried by nanoparticles with various material types, shapes, sizes, coated ligands, associated loading methods, hydrophilicities, elasticities, and biocompatibilities. In this review, the principal types of nanovectors (nanopharmaceutics and bioinspired nanoparticles) are summarized along with the shortcomings in nanoparticle delivery and the main factors that modulate efficacy (the EPR effect, protein coronas, and microbiota). The mechanisms by which nanovectors can target cancer cells, the tumor immune microenvironment (TIME), and the peripheral immune system are also presented. A possible mathematical model for the cellular communication mechanisms related to exosomes as nanocarriers is proposed.

Nanocarriers Call the Last Shot in the Treatment of Brain Cancers

Our brain is protected by physio-biological barriers. The blood–brain barrier (BBB) main mechanism of protection relates to the abundance of tight junctions (TJs) and efflux pumps. Although BBB is crucial for healthy brain protection against toxins, it also leads to failure in a devastating disease like brain cancer. Recently, nanocarriers have been shown to pass through the BBB and improve patients’ survival rates, thus becoming promising treatment strategies. Among nanocarriers, inorganic nanocarriers, solid lipid nanoparticles, liposomes, polymers, micelles, and dendrimers have reached clinical trials after delivering promising results in preclinical investigations. The size of these nanocarriers is between 10 and 1000 nm and is modified by surface attachment of proteins, peptides, antibodies, or surfactants. Multiple research groups have reported transcellular entrance as the main mechanism allowing for these nanocarriers to cross BBB. Transport proteins and transcellular lipophilic pathways exist in BBB for small and lipophilic molecules. Nanocarriers cannot enter via the paracellular route, which is limited to water-soluble agents due to the TJs and their small pore size. There are currently several nanocarriers in clinical trials for the treatment of brain cancer. This article reviews challenges as well as fitting attributes of nanocarriers for brain tumor treatment in preclinical and clinical studies.

Emerging Nano-Carrier Strategies for Brain Tumor Drug Delivery and Considerations for Clinical Translation

Treatment of brain tumors is challenging since the blood–brain tumor barrier prevents chemotherapy drugs from reaching the tumor site in sufficient concentrations. Nanomedicines have great potential for therapy of brain disorders but are still uncommon in clinical use despite decades of research and development. Here, we provide an update on nano-carrier strategies for improving brain drug delivery for treatment of brain tumors, focusing on liposomes, extracellular vesicles and biomimetic strategies as the most clinically feasible strategies. Finally, we describe the obstacles in translation of these technologies including pre-clinical models, analytical methods and regulatory issues.

A Perspective on Modelling Metallic Magnetic Nanoparticles in Biomedicine: From Monometals to Nanoalloys and Ligand-Protected Particles

The focus of this review is on the physical and magnetic properties that are related to the efficiency of monometallic magnetic nanoparticles used in biomedical applications, such as magnetic resonance imaging (MRI) or magnetic nanoparticle hyperthermia, and how to model these by theoretical methods, where the discussion is based on the example of cobalt nanoparticles. Different simulation systems (cluster, extended slab, and nanoparticle models) are critically appraised for their efficacy in the determination of reactivity, magnetic behaviour, and ligand-induced modifications of relevant properties. Simulations of the effects of nanoscale alloying with other metallic phases are also briefly reviewed.

Production and Characterization of Motile and Chemotactic Bacterial Minicells

Minicells are nanosized membrane vesicles produced by bacteria. Minicells are chromosome-free but contain cellular biosynthetic and metabolic machinery, and they are robust due to the protection provided by the bacterial cell envelope, which makes them potentially highly attractive in biomedical applications. However, the applicability of minicells and other nanoparticle-based delivery systems is limited by their inefficient accumulation at the target. Here we engineered the minicell-producing Escherichia coli strain to overexpress flagellar genes, which enables the generation of motile minicells. We subsequently performed an experimental and theoretical analysis of the minicell motility and their responses to gradients of chemoeffectors. Despite important differences between the motility of minicells and normal bacterial cells, minicells were able to bias their movement in chemical gradients and to accumulate toward the sources of chemoattractants. Such motile and chemotactic minicells may thus be applicable for an active effector delivery and specific targeting of tissues and cells according to their metabolic profiles.

Bio-Nanocarriers for Lung Cancer Management: Befriending the Barriers

Lung cancer is a complex thoracic malignancy developing consequential to aberrations in a myriad of molecular and biomolecular signaling pathways. It is one of the most lethal forms of cancers accounting to almost 1.8 million new annual incidences, bearing overall mortality to incidence ratio of 0.87. The dismal prognostic scenario at advanced stages of the disease and metastatic/resistant tumor cell populations stresses the requisite of advanced translational interdisciplinary interventions such as bionanotechnology. This review article deliberates insights and apprehensions on the recent prologue of nanobioengineering and bionanotechnology as an approach for the clinical management of lung cancer. The role of nanobioengineered (bio-nano) tools like bio-nanocarriers and nanobiodevices in secondary prophylaxis, diagnosis, therapeutics, and theranostics for lung cancer management has been discussed. Bioengineered, bioinspired, and biomimetic bio-nanotools of considerate translational value have been reviewed. Perspectives on existent oncostrategies, their critical comparison with bio-nanocarriers, and issues hampering their clinical bench side to bed transformation have also been summarized.

miRNA in cardiac development and regeneration

Ischemic heart disease is one of the main causes of morbidity and mortality in the world. In adult mammalian hearts, most cardiomyocytes are terminally differentiated and have extremely limited capacity of proliferation, making it impossible to regenerate the heart after injuries such as myocardial infarction. MicroRNAs (miRNAs), a class of non-coding single-stranded RNA, which are involved in mRNA silencing and the regulation of post-transcriptional gene expression, have been shown to play a crucial role in cardiac development and cardiomyocyte proliferation. Muscle specific miRNAs such as miR-1 are key regulators of cardiomyocyte maturation and growth, while miR-199-3p and other miRNAs display potent activity to induce proliferation of cardiomyocytes. Given their small size and relative pleiotropic effects, miRNAs have gained significant attraction as promising therapeutic targets or tools in cardiac regeneration. Increasing number of studies demonstrated that overexpression or inhibition of specific miRNAs could induce cardiomyocyte proliferation and cardiac regeneration. Some common targets of pro-proliferation miRNAs, such as the Hippo-Yap signaling pathway, were identified in multiple species, highlighting the power of miRNAs as probes to dissect core regulators of biological processes. A number of miRNAs have been shown to improve heart function after myocardial infarction in mice, and one trial in swine also demonstrated promising outcomes. However, technical difficulties, especially in delivery methods, and adverse effects, such as uncontrolled proliferation, remain. In this review, we summarize the recent progress in miRNA research in cardiac development and regeneration, examine the mechanisms of miRNA regulating cardiomyocyte proliferation, and discuss its potential as a new strategy for cardiac regeneration therapy.

Nanocell-mediated delivery of miR-34a counteracts temozolomide resistance in glioblastoma

BACKGROUND

Glioblastoma is the most common primary brain tumor and remains uniformly fatal, highlighting the dire need for developing effective therapeutics. Significant intra- and inter-tumor heterogeneity and inadequate delivery of therapeutics across blood-brain barrier continue to be significant impediments towards developing therapies which can significantly enhance survival. We hypothesize that microRNAs have the potential to serve as effective therapeutics for glioblastoma as they modulate the activity of multiple signaling pathways, and hence can counteract heterogeneity if successfully delivered.

METHODS

Using a computational approach, we identified microRNA-34a as a microRNA that maximally reduces the activation status of the three core signaling networks (the receptor tyrosine kinase, p53 and Rb networks) that have been found to be deregulated in most glioblastoma tumors. Glioblastoma cultures were transfected with microRNA-34a or control microRNA to assess biological function and therapeutic potential in vitro. Nanocells were derived from genetically modified bacteria and loaded with microRNA-34a for intravenous administration to orthotopic patient-derived glioblastoma xenografts in mice.

RESULTS

Overexpression of microRNA-34a strongly reduced the activation status of the three core signaling networks. microRNA-34a transfection also inhibited the survival of multiple established glioblastoma cell lines, as well as primary patient-derived xenograft cultures representing the proneural, mesenchymal and classical subtypes. Transfection of microRNA-34a enhanced temozolomide (TMZ) response in in vitro cultures of glioblastoma cells with primary TMZ sensitivity, primary TMZ resistance and acquired TMZ resistance. Mechanistically, microRNA-34a downregulated multiple therapeutic resistance genes which are associated with worse survival in glioblastoma patients and are enriched in specific tumor spatial compartments. Importantly, intravenous administration of nanocells carrying miR-34a and targeted to epidermal growth factor receptor (EGFR) strongly enhanced TMZ sensitivity in an orthotopic patient-derived xenograft mouse model of glioblastoma.

CONCLUSIONS

Targeted bacterially-derived nanocells are an effective vehicle for the delivery of microRNA-34a to glioblastoma tumors. microRNA-34a inhibits survival and strongly sensitizes a wide range of glioblastoma cell cultures to TMZ, suggesting that combination therapy of TMZ with microRNA-34a loaded nanocells may serve as a novel therapeutic approach for the treatment of glioblastoma tumors.

Delivery of cancer therapies by synthetic and bio-inspired nanovectors

BACKGROUND

As a complement to the clinical development of new anticancer molecules, innovations in therapeutic vectorization aim at solving issues related to tumor specificity and associated toxicities. Nanomedicine is a rapidly evolving field that offers various solutions to increase clinical efficacy and safety. MAIN: Here are presented the recent advances for different types of nanovectors of chemical and biological nature, to identify the best suited for translational research projects. These nanovectors include different types of chemically engineered nanoparticles that now come in many different flavors of 'smart' drug delivery systems. Alternatives with enhanced biocompatibility and a better adaptability to new types of therapeutic molecules are the cell-derived extracellular vesicles and micro-organism-derived oncolytic viruses, virus-like particles and bacterial minicells. In the first part of the review, we describe their main physical, chemical and biological properties and their potential for personalized modifications. The second part focuses on presenting the recent literature on the use of the different families of nanovectors to deliver anticancer molecules for chemotherapy, radiotherapy, nucleic acid-based therapy, modulation of the tumor microenvironment and immunotherapy.

CONCLUSION

This review will help the readers to better appreciate the complexity of available nanovectors and to identify the most fitting "type" for efficient and specific delivery of diverse anticancer therapies.

Non-coding RNA therapeutics for cardiac regeneration

A growing body of evidence indicates that cardiac regeneration after myocardial infarction can be achieved by stimulating the endogenous capacity of cardiomyocytes (CMs) to replicate. This process is controlled, both positively and negatively, by a large set of non-coding RNAs (ncRNAs). Some of the microRNAs (miRNAs) that can stimulate CM proliferation is expressed in embryonic stem cells and is required to maintain pluripotency (e.g. the miR-302∼367 cluster). Others also govern the proliferation of different cell types, including cancer cells (e.g. the miR-17∼92 cluster). Additional miRNAs were discovered through systematic screenings (e.g. miR-199a-3p and miR-590-3p). Several miRNAs instead suppress CM proliferation and are involved in the withdrawal of CMs from the cell cycle after birth (e.g. the let-7 and miR-15 families). Similar regulatory roles on CM proliferation are also exerted by a few long ncRNAs. This body of information has obvious therapeutic implications, as miRNAs with activator function or short antisense oligonucleotides against inhibitory miRNAs or lncRNAs can be administered to stimulate cardiac regeneration. Expression of miRNAs can be achieved by gene therapy using adeno-associated vectors, which transduce CMs with high efficiency. More effective and safer for therapeutic purposes, small nucleic acid therapeutics can be obtained as chemically modified, synthetic molecules, which can be administered through lipofection or inclusion in lipid or polymer nanoparticles for efficient cardiac delivery. The notion that it is possible to reprogramme CMs into a regenerative state and that this property can be enhanced by ncRNA therapeutics remains exciting, however extensive experimentation in large mammals and rigorous assessment of safety are required to advance towards clinical application.

Gene Therapy as an Emerging Therapeutic Approach to Breast Cancer: New Developments and Challenges

Breast cancer is a heterogeneous disease, which is the consequence of several genetic and environmental factors. Also, it is one of the most common causes of cancer death and second leading cancer among women all around the world. Therefore, it is necessary to develop novel therapeutic approaches useful for the successful treatment of breast cancer. As conventional treatments had limited success, alternative approaches for the treatment of breast cancer have been applied in recent years. Hence, the molecular basis of breast cancer has provided the opportunity of using genetic materials for therapeutic uses. In this regard, gene therapy as one of the potentially efficient and beneficial treatments among various techniques became a popular treatment for different cancers, especially breast cancer. Accordingly, there are plenty of targets available for gene therapy of breast cancer. Gene therapy strategies have the potential to correct molecular defects that contributed to the cancer progression. These techniques should selectively target tumor cells without affecting normal cells. Moreover, data of clinical trials in gene therapy for breast cancer indicated that this approach has little toxicity compared to other therapeutic approaches. In this study, different aspects of breast neoplasm, gene therapy techniques, challenges, and recent developments will be mentioned.

New technologies in developing recombinant-attenuated bacteria for cancer therapy

Cancer has always been a global problem, with more cases of cancer patients being diagnosed every year. Conventional cancer treatments, including radiotherapy, chemotherapy, and surgery, are still unable to bypass their obvious limitations, and developing effective targeted therapies is still required. More than one century ago, the doctor William B. Coley discovered that cancer patients had tumor regression by injection of Streptococcus bacteria. The studies of cancer therapy using bacterial microorganisms are now very widespread. In particular, the facultative anaerobic bacteria Salmonella typhimurium is widely investigated as it can selectively colonize different types of tumors, locally deliver various antitumor drugs, and inhibit tumor growth. The exciting antitumor efficacy and safety observed in animal tumor models prompted the well-known attenuated Salmonella bacterial strain VNP20009 to be tested in human clinical trials in the early 21st century. Regrettably, no patients showed significant therapeutic effects and even bacterial colonization in tumor tissue was undetectable in most patients. Salmonella bacteria are still considered as a promising agent or vehicle for cancer therapy. Recent efforts have been focused on the generation of attenuated bacterial strains with higher targeting for tumor tissue, and optimization of the delivery of therapeutic antitumor cargoes into the tumor microenvironment. This review will summarize new technologies or approaches that may improve bacteria-mediated cancer therapy.

Gene Therapy for the Heart Lessons Learned and Future Perspectives

While clinical gene therapy celebrates its first successes, with several products already approved for clinical use and several hundreds in the final stages of the clinical approval pipeline, there is not a single gene therapy approach that has worked for the heart. Here, we review the past experience gained in the several cardiac gene therapy clinical trials that had the goal of inducing therapeutic angiogenesis in the ischemic heart and in the attempts at modulating cardiac function in heart failure. Critical assessment of the results so far achieved indicates that the efficiency of cardiac gene delivery remains a major hurdle preventing success but also that improvements need to be sought in establishing more reliable large animal models, choosing more effective therapeutic genes, better designing clinical trials, and more deeply understanding cardiac biology. We also emphasize a few areas of cardiac gene therapy development that hold great promise for the future. In particular, the transition from gene addition studies using protein-coding cDNAs to the modulation of gene expression using small RNA therapeutics and the improvement of precise gene editing now pave the way to applications such as cardiac regeneration after myocardial infarction and gene correction for inherited cardiomyopathies that were unapproachable until a decade ago.

RNA-Based Therapeutics: From Antisense Oligonucleotides to miRNAs

The first therapeutic nucleic acid, a DNA oligonucleotide, was approved for clinical use in 1998. Twenty years later, in 2018, the first therapeutic RNA-based oligonucleotide was United States Food and Drug Administration (FDA) approved. This promises to be a rapidly expanding market, as many emerging biopharmaceutical companies are developing RNA interference (RNAi)-based, and RNA-based antisense oligonucleotide therapies. However, miRNA therapeutics are noticeably absent. miRNAs are regulatory RNAs that regulate gene expression. In disease states, the expression of many miRNAs is measurably altered. The potential of miRNAs as therapies and therapeutic targets has long been discussed and in the context of a wide variety of infections and diseases. Despite the great number of studies identifying miRNAs as potential therapeutic targets, only a handful of miRNA-targeting drugs (mimics or inhibitors) have entered clinical trials. In this review, we will discuss whether the investment in finding potential miRNA therapeutic targets has yielded feasible and practicable results, the benefits and obstacles of miRNAs as therapeutic targets, and the potential future of the field.

Improved Nucleic Acid Therapy with Advanced Nanoscale Biotechnology

Due to a series of systemic and intracellular obstacles in nucleic acid (NA) therapy, including fast degradation in blood, renal clearance, poor cellular uptake, and inefficient endosomal escape, NAs may need delivery methods to transport to the cell nucleus or cytosol to be effective. Advanced nanoscale biotechnology-associated strategies, such as controlling the particle size, charge, drug loading, response to environmental signals, or other physical/chemical properties of delivery carriers, have provided great help for the in vivo and in vitro delivery of NA therapeutics. In this review, we introduce the characteristics of different NA modalities and illustrate how advanced nanoscale biotechnology assists NA therapy. The specific features and challenges of various nanocarriers in clinical and preclinical studies are summarized and discussed. With the help of advanced nanoscale biotechnology, some of the major barriers to the development of NA therapy will eventually be overcome in the near future.

Antibody-based nanotechnology

Antibodies are considered the hallmark of the adaptive immune system in that they mediate various key biological functions, such as direct neutralization and recruitment of effector immune cells to eliminate invading pathogens. Antibodies exhibit several unique properties, including high diversity (enabling binding to a wide range of targets), high specificity and structural integrity. These properties and the understanding that antibodies can be utilized in a wide range of applications have motivated the scientific community to develop new approaches for antibody repertoire analysis and rapid monoclonal antibody discovery. Today, antibodies are key modules in the pharmaceutical and diagnostic industries. By virtue of their high affinity and specificity to their targets and the availability of technologies to engineer different antibodies to a wide range of targets, antibodies have become the most promising natural biological molecules in a range of biotechnological applications, such as: highly specific and sensitive nanobiosensors for the diagnostics of different biomarkers; nanoparticle-based targeted drug delivery systems to certain cells or tissues; and nanomachines, which are nanoscale mechanical devices that enable energy conversion into precise mechanical motions in response to specific molecular inputs. In this review, we start by describing the unique properties of antibodies, how antibody diversity is generated, and the available technologies for antibody repertoire analysis and antibody discovery. Thereafter, we provide an overview of some antibody-based nanotechnologies and discuss novel and promising approaches for the application of antibodies in the nanotechnology field. Overall, we aim to bridge the knowledge gap between the nanotechnology and antibody engineering disciplines by demonstrating how technological advances in the antibody field can be leveraged to develop and/or enhance new technological approaches in the nanotechnology field.

Clinical advances of siRNA therapeutics

Small interfering RNA (siRNA) enables efficient target gene silencing by employing a RNA interference (RNAi) mechanism, which can compromise gene expression and regulate gene activity by cleaving mRNA or repressing its translation. Twenty years after the discovery of RNAi in 1998, ONPATTRO™ (patisiran) (Alnylam Pharmaceuticals, Inc.), a lipid formulated siRNA modality, was approved for the first time by United States Food and Drug Administration and the European Commission in 2018. With this milestone achievement, siRNA therapeutics will soar in the coming years. Here, we review the discovery and the mechanisms of RNAi, briefly describe the delivery technologies of siRNA, and summarize recent clinical advances of siRNA therapeutics.

RNAi therapeutic and its innovative biotechnological evolution

Recently, United States Food and Drug Administration (FDA) and European Commission (EC) approved Alnylam Pharmaceuticals' RNA interference (RNAi) therapeutic, ONPATTRO™ (Patisiran), for the treatment of the polyneuropathy of hereditary transthyretin-mediated (hATTR) amyloidosis in adults. This is the first RNAi therapeutic all over the world, as well as the first FDA-approved treatment for this indication. As a milestone event in RNAi pharmaceutical industry, it means, for the first time, people have broken through all development processes for RNAi drugs from research to clinic. With this achievement, RNAi approval may soar in the coming years. In this paper, we introduce the basic information of ONPATTRO and the properties of RNAi and nucleic acid therapeutics, update the clinical and preclinical development activities, review its complicated development history, summarize the key technologies of RNAi at early stage, and discuss the latest advances in delivery and modification technologies. It provides a comprehensive view and biotechnological insights of RNAi therapy for the broader audiences.

Treatment and management of adrenal cancer in a specialized Australian endocrine surgical unit: approaches, outcomes and lessons learnt

BACKGROUND

Adrenocortical carcinoma is a rare and heterogeneous malignancy with poor outcomes. Recent research has suggested that outcomes may be improved by centralization of care in specialist centres. We review our evolving 21-year experience in managing adrenocortical carcinoma with a view towards outcomes and lessons learnt.

METHODS

A retrospective study of patients treated in our specialist endocrine surgical unit over 21 years was undertaken.

RESULTS

Thirty-five patients were treated from diagnosis, 29 forming a primary study cohort. Additionally, seven patients were referred to us for quaternary care, forming a secondary study cohort. The European Network for the Study of Adrenal Tumours (ENSAT) stage and immunohistochemical marker Ki-67 index were strong prognostic indicators for survival.

CONCLUSIONS

Early stage, complete resection and Ki-67 <10% are the best prognosticators for survival. Aggressive surgical resection at index operation and of recurrent oligometastatic disease along with multimodal adjuvant treatment has led to long-term survivors of patients with Stage 4 disease in our aggregate cohort.

RNA interference to enhance radiation therapy: Targeting the DNA damage response

RNA interference (RNAi) therapy is an emerging class of biopharmaceutical that has immense potential in cancer medicine. RNAi medicines are based on synthetic oligonucleotides that can suppress a target protein in tumour cells with high specificity. This review explores the attractive prospect of using RNAi as a radiosensitiser by targeting the DNA damage response. There are a multitude of molecular targets involved in the detection and repair of DNA damage that are suitable for this purpose. Recent developments in delivery technologies such nanoparticle carriers and conjugation strategies have allowed RNAi therapeutics to enter clinical trials in the treatment of cancer. With further progress, RNAi targeting of the DNA damage response may hold great promise in guiding radiation oncology into the era of precision medicine.

Nucleic Acid-Based Therapeutics for Pulmonary Diseases

Nucleic acid-based therapeutics present huge potential in the treatment of pulmonary diseases ranging from lung cancer to asthma and chronic pulmonary diseases, which are often fatal and widely prevalent. The susceptibility of nucleic acids to degradation and the complex structure of lungs retard the effective pulmonary delivery of nucleic acid drug. To overcome these barriers, different strategies have been exploited to increase the delivery efficiency using chemically synthesized nucleic acids, vector encapsulation, proper formulation, and administration route. However, several limitations regarding off-target effects and immune stimulation of nucleic acid drugs hamper their translation into the clinical practice. Therefore, their successful clinical application will ultimately rely on well-developed carriers and methods to ensure safety and efficacy. In this review, we provide a comprehensive overview of the nucleic acid application for pulmonary diseases, covering action mechanism of the nucleic acid drugs, the novel delivery systems, and the current formulation for the administration to lungs. The latest advances of nucleic acid drugs under clinical evaluation to treat pulmonary disorders will also be detailed.

Safety and activity of microRNA-loaded minicells in patients with recurrent malignant pleural mesothelioma: a first-in-man, phase 1, open-label, dose-escalation study

BACKGROUND

TargomiRs are minicells (EnGeneIC Dream Vectors) loaded with miR-16-based mimic microRNA (miRNA) and targeted to EGFR that are designed to counteract the loss of the miR-15 and miR-16 family miRNAs, which is associated with unsuppressed tumour growth in preclinical models of malignant pleural mesothelioma. We aimed to assess the safety, optimal dosing, and activity of TargomiRs in patients with malignant pleural mesothelioma.

METHODS

In this first-in-man, open-label, dose-escalation phase 1 trial at three major cancer centres in Sydney (NSW, Australia), we recruited adults (aged ≥18 years) with a confirmed diagnosis of malignant pleural mesothelioma, measurable disease, radiological signs of progression after previous chemotherapy, Eastern Cooperative Oncology Group performance status of 0 or 1, life expectancy of 3 months or more, immunohistochemical evidence of tumour EGFR expression, and adequate bone marrow, liver, and renal function. Patients were given TargomiRs via 20 min intravenous infusion either once or twice a week (3 days apart) in a traditional 3 + 3 dose-escalation design in five dose cohorts. The dose-escalation steps planned were 5 × 10⁹, 7 × 10⁹, and 9 × 10⁹ TargomiRs either once or twice weekly, but after analysis of data from the first eight patients, all subsequent patients started protocol treatment at 1 × 10⁹ TargomiRs. The primary endpoints were to establish the maximum tolerated dose of TargomiRs as measured by dose-limiting toxicity, define the optimal frequency of administration, and objective response (defined as the percentage of assessable patients with a complete or partial response), duration of response (defined as time from the first evidence of response to disease progression in patients who achieved a response), time to response (ie, time from start of treatment to the first evidence of response) and overall survival (defined as time from treatment allocation to death from any cause). Analyses were based on the full analysis set principle, including every patient who received at least one dose of TargomiRs. The study was closed for patient entry on Jan 3, 2017, and registered with ClinicalTrials.gov, number NCT02369198, and the Australian Registry of Clinical Trials, number ACTRN12614001248651.

FINDINGS

Between Sept 29, 2014, and Nov 24, 2016, we enrolled 27 patients, 26 of whom received at least one TargomiR dose (one patient died before beginning treatment). Overall, five dose-limiting toxicities were noted: infusion-related inflammatory symptoms and coronary ischaemia, respectively, in two patients given 5 × 10⁹ TargomiRs twice weekly; anaphylaxis and cardiomyopathy, respectively, in two patients given 5 × 10⁹ TargomiRs once weekly but who received reduced dexamethasone prophylaxis; and non-cardiac pain in one patient who received 5 × 10⁹ TargomiRs once weekly. We established that 5 × 10⁹ TargomiRs once weekly was the maximum tolerated dose. TargomiR infusions were accompanied by transient lymphopenia (25 [96%] of 26 patients), temporal hypophosphataemia (17 [65%] of 26 patients), increased aspartate aminotransferase or alanine aminotranferase (six [23%] of 26 patients), and increased alkaline phosphatase blood concentrations (two [8%]). Cardiac events occurred in five patients: three patients had electrocardiographic changes, one patient had ischaemia, and one patient had Takotsubo cardiomyopathy. Of the 22 patients who were assessed for response by CT, one (5%) had a partial response, 15 (68%) had stable disease, and six (27%) had progressive disease. The proportion of patients who achieved an objective response was therefore one (5%) of 22, and the duration of the objective response in that patient was 32 weeks. Median overall survival was 200 days (95% CI 94-358). During the trial, 21 deaths occurred, of which 20 were related to tumour progression and one was due to bowel perforation.

INTERPRETATION

The acceptable safety profile and early signs of activity of TargomiRs in patients with malignant pleural mesothelioma support additional studies of TargomiRs in combination with chemotherapy or immune checkpoint inhibitors.

FUNDING

Asbestos Diseases Research Foundation.

Targeting microRNA to improve diagnostic and therapeutic approaches for malignant mesothelioma

Malignant mesothelioma is an aggressive and often fatal cancer associated with asbestos exposure. The disease originates in the mesothelial lining of the serosal cavities, most commonly affecting the pleura. Survival rates are low as diagnosis often occurs at an advanced stage and current treatments are limited. Identifying new diagnostic and therapeutic targets for mesothelioma remains a priority, particularly for the new wave of victims exposed to asbestos through do-it-yourself renovations and in countries where asbestos is still mined and used. Recent advances have demonstrated a biological role for the small but powerful gene regulators microRNA (miRNA) in mesothelioma. A number of potential therapeutic targets have been identified. MiRNA have also become popular as potential biomarkers for mesothelioma due to their stable expression in bodily fluid and tissues. In this review, we highlight the current challenges associated with the diagnosis and treatment of mesothelioma and discuss how targeting miRNA may improve diagnostic, prognostic and therapeutic approaches.

Enzyme/Prodrug Systems for Cancer Gene Therapy

The use of enzyme/prodrug system has gained attention because it could help improve the efficacy and safety of conventional cancer chemotherapies. In this approach, cancer cells are first transfected with a gene that can express an enzyme with ability to convert a non-toxic prodrug into its active cytotoxic form. As a result, the activated prodrug could kill the transfected cancer cells. Despite the significant progress of different suicide gene therapy protocols in preclinical studies and early clinical trials, none has reached the clinic due to several shortcomings. These include slow prodrug-drug conversion rate, low transfection/transduction efficiency of the vectors and nonspecific toxicity/immunogenicity related to the delivery systems, plasmid DNA, enzymes and/or prodrugs. This mini review aims at providing an overview of the most widely used enzyme/prodrug systems with emphasis on reporting the results of the recent preclinical and clinical studies.

NANOMEDICINE: will it offer possibilities to overcome multiple drug resistance in cancer?

This review is written with the purpose to review the current nanomedicine literature and provide an outlook on the developments in utilizing nanoscale drug constructs in treatment of solid cancers as well as in the potential treatment of multi-drug resistant cancers. No specific design principles for this review have been utilized apart from our active choice to avoid results only based on in vitro studies. Few drugs based on nanotechnology have progressed to clinical trials, since most are based only on in vitro experiments which do not give the necessary data for the research to progress towards pre-clinical studies. The area of nanomedicine has indeed spark much attention and holds promise for improved future therapeutics in the treatment of solid cancers. However, despite much investment few targeted therapeutics have successfully progressed to early clinical trials, indicating yet again that the human body is complicated and that much more understanding of the fundamentals of receptor interactions, physics of nanomedical constructs and their circulation in the body is indeed needed. We believe that nanomedical therapeutics can allow for more efficient treatments of resistant cancers, and may well be a cornerstone for RNA based therapeutics in the future given their general need for shielding from the harsh environment in the blood stream.

A First-Time-In-Human Phase I Clinical Trial of Bispecific Antibody-Targeted, Paclitaxel-Packaged Bacterial Minicells

BACKGROUND

We have harnessed a novel biological system, the bacterial minicell, to deliver cancer therapeutics to cancer cells. Preclinical studies showed that epidermal growth factor receptor (EGFR)-targeted, paclitaxel-loaded minicells (EGFRminicellsPac) have antitumor effects in xenograft models. To examine the safety of the minicell delivery system, we initiated a first-time-in-human, open-label, phase I clinical study of EGFRminicellsPac in patients with advanced solid tumors.

METHODOLOGY

Patients received 5 weekly infusions followed by a treatment free week. Seven dose levels (1x108, 1x109, 3x109, 1x1010, 1.5x1010, 2x1010, 5x1010) were evaluated using a 3+3 dose-escalation design. Primary objectives were safety, tolerability and determination of the maximum tolerated dose. Secondary objectives were assessment of immune/inflammatory responses and antitumor activity.

PRINCIPAL FINDINGS

Twenty eight patients were enrolled, 22 patients completed at least one cycle of EGFRminicellsPac; 6 patients did not complete a cycle due to rapidly progressive disease. A total of 236 doses was delivered over 42 cycles, with a maximum of 45 doses administered to a single patient. Most common treatment-related adverse events were rigors and pyrexia. No deaths resulted from treatment-related adverse events and the maximum tolerated dose was defined as 1x1010 EGFRminicellsPac. Surprisingly, only a mild self-limiting elevation in the inflammatory cytokines IL-6, IL-8 and TNFα and anti-inflammatory IL-10 was observed. Anti-LPS antibody titers peaked by dose 3 and were maintained at that level despite repeat dosing with the bacterially derived minicells. Ten patients (45%; n = 22) achieved stable disease as their best response.

CONCLUSIONS/SIGNIFICANCE

This is the first study in humans of a novel biological system that can provide targeted delivery of a range of chemotherapeutic drugs to solid tumor cells. Bispecific antibody-targeted minicells, packaged with the chemotherapeutic paclitaxel, were shown to be safe in patients with advanced solid tumors with modest clinical efficacy observed. Further study in Phase II trials is planned.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry ACTRN12609000672257.

Nanocell targeting using engineered bispecific antibodies

There are many design formats for bispecific antibodies (BsAbs), and the best design choice is highly dependent on the final application. Our aim was to engineer BsAbs to target a novel nanocell (EnGeneIC Delivery Vehicle or EDV^TMnanocell) to the epidermal growth factor receptor (EGFR). EDV^TMnanocells are coated with lipopolysaccharide (LPS), and BsAb designs incorporated single chain Fv (scFv) fragments derived from an anti-LPS antibody (1H10) and an anti-EGFR antibody, ABX-EGF. We engineered various BsAb formats with monovalent or bivalent binding arms and linked scFv fragments via either glycine-serine (G4S) or Fc-linkers. Binding analyses utilizing ELISA, surface plasmon resonance, bio-layer interferometry, flow cytometry and fluorescence microscopy showed that binding to LPS and to either soluble recombinant EGFR or MDA-MB-468 cells expressing EGFR, was conserved for all construct designs. However, the Fc-linked BsAbs led to nanocell clumping upon binding to EDV^TMnanocells. Clumping was eliminated when additional disulfide bonds were incorporated into the scFv components of the BsAbs, but this resulted in lower BsAb expression. The G4S-linked tandem scFv BsAb format was the optimal design with respect to EDV binding and expression yield. Doxorubicin-loaded EDV^TMnanocells actively targeted with tandem scFv BsAb in vivo to MDA-MB-468-derived tumors in mouse xenograft models enhanced tumor regression by 40% compared to passively targeted EDV^TMnanocells. BsAbs therefore provide a functional means to deliver EDV^TMnanocells to target cells.

miRNA therapeutics: a new class of drugs with potential therapeutic applications in the heart

miRNAs are small non-coding RNAs (ncRNAs), which regulate gene expression. Here, the authors describe the contribution of miRNAs to cardiac biology and disease. They discuss various strategies for manipulating miRNA activity including antisense oligonucleotides (antimiRs, blockmiRs), mimics, miRNA sponges, Tough Decoys and miRNA mowers. They review developments in chemistries (e.g., locked nucleic acid) and modifications (sugar, 'ZEN', peptide nucleic acids) and miRNA delivery tools (viral vectors, liposomes, nanoparticles, pHLIP). They summarize potential miRNA therapeutic targets for heart disease based on preclinical studies. Finally, the authors review current progress of miRNA therapeutics in clinical development for HCV and cancer, and discuss challenges that will need to be overcome for similar therapies to enter the clinic for patients with cardiac disease.

Latest developments in our understanding of the pathogenesis of mesothelioma and the design of targeted therapies

Malignant mesothelioma is an aggressive cancer whose pathogenesis is causally linked to occupational exposure to asbestos. Familial clusters of mesotheliomas have been observed in settings of genetic predisposition. Mesothelioma incidence is anticipated to increase worldwide in the next two decades. Novel treatments are needed, as current treatment modalities may improve the quality of life, but have shown modest effects in improving overall survival. Increasing knowledge on the molecular characteristics of mesothelioma has led to the development of novel potential therapeutic strategies, including: molecular targeted approaches, that is the inhibition of vascular endothelial growth factor with bevacizumab; immunotherapy with chimeric monoclonal antibody, immunotoxin, antibody drug conjugate, vaccine and viruses; inhibition of asbestos-induced inflammation, that is aspirin inhibition of HMGB1 activity may decrease or delay mesothelioma onset and/or growth. We elaborate on the rationale behind new therapeutic strategies, and summarize available preclinical and clinical results, as well as efforts still ongoing.

First in human nanotechnology doxorubicin delivery system to target epidermal growth factor receptors in recurrent glioblastoma

There are limited treatment options for patients with recurrent glioblastoma (GBM). The EnGeneIC delivery vehicle (EDV) is a novel nanocellular (minicell) compound which packages theoretically effective concentrations of chemotherapeutic drugs that are designed to target tumors via minicell-surface attached bispecific proteins (EnGeneIC, Lane Cove West, NSW, Australia). Epidermal growth factor receptor (EGFR) is overexpressed in 40-50% of patients with GBM and is a promising target for new therapeutics. (V)EDVDox contains doxorubicin (Dox) within the minicells and targets EGFR through Vectibix (V; Amgen Biologicals, Thousand Oaks, CA, USA). We conducted a first in human Phase I study of (V)EDVDox in adults with recurrent GBM expressing EGFR on immunohistochemistry, following standard therapy including radiation and temozolomide, to establish a safe maximum tolerated dose and determine a recommended Phase II dose (RPTD). (V)EDVDox was administered weekly in an 8week cycle, with dose escalation in successive cohorts of patients using a standard 3+3 design. In total, 14 patients were treated at three dose levels, and the RPTD was identified as 5×10(9)(V)EDVDox. Overall (V)EDVDox was well tolerated, with no dose limiting toxicity and no withdrawals from the study due to adverse events. The most common adverse events were nausea, fever, and chills or rigors, experienced in seven, five and five patients, respectively. Transient uncomplicated hypophosphatemia was seen in seven patients and was not dose-related. Our results demonstrate that (V)EDVDox, up to a dose of 5×10(9)(V)EDVDox weekly, is well tolerated in patients with recurrent GBM.

Potent and tumor specific: arming bacteria with therapeutic proteins

Bacteria are perfect vessels for targeted cancer therapy. Conventional chemotherapy is limited by passive diffusion, and systemic administration causes severe side effects. Bacteria can overcome these obstacles by delivering therapeutic proteins specifically to tumors. Bacteria have been modified to produce proteins that directly kill cells, induce apoptosis via signaling pathways, and stimulate the immune system. These three modes of bacterial treatment have all been shown to reduce tumor growth in animal models. Bacteria have also been designed to convert nontoxic prodrugs to active therapeutic compounds. The ease of genetic manipulation enables creation of arrays of bacteria that release many new protein drugs. This versatility will allow targeting of multiple cancer pathways and will establish a platform for individualized cancer medicine.

MicroRNAs in mesothelioma: from tumour suppressors and biomarkers to therapeutic targets

Malignant mesothelioma remains a difficult proposition in the clinic, with few accurate molecular markers available to guide diagnosis and patient management, and a dearth of effective treatments. Recent evidence implicates microRNAs-short non-coding RNAs involved in post-transcriptional regulation of gene expression-in mesothelioma biology. Emerging evidence suggests that exploring aberrant microRNA expression will not only improve our understanding of the disease, but will also lead to the identification of new molecular biomarkers and therapeutic targets.

Cancer stem cells: a challenging paradigm for designing targeted drug therapies

Despite earlier controversies about their role and existence within tumors, cancer stem cells (CSCs) are now emerging as a plausible target for new drug discovery. Research and development (R&D) efforts are being directed against key gene(s) driving initiation, growth, and metastatic pathways in CSCs and the tumor microenvironment (TME). However, the niche signals that enable these pluripotent CSCs to evade radio- and chemotherapy, and to travel to secondary tissues remain enigmatic. Small-molecule drugs, biologics, miRNA, RNA interference (RNAi), and vaccines, among others, are under active investigation. Here, we examine the feasibility of leveraging current knowhow of the molecular biology of CSCs and their cellular milieu to design futuristic, targeted drugs with potentially lower toxicity that can override the multiple drug-resistance issues currently observed with existing therapeutics.

The Min system and other nucleoid-independent regulators of Z ring positioning

Rod-shaped bacteria such as E. coli have mechanisms to position their cell division plane at the precise center of the cell, to ensure that the daughter cells are equal in size. The two main mechanisms are the Min system and nucleoid occlusion (NO), both of which work by inhibiting assembly of FtsZ, the tubulin-like scaffold that forms the cytokinetic Z ring. Whereas NO prevents Z rings from constricting over unsegregated nucleoids, the Min system is nucleoid-independent and even functions in cells lacking nucleoids and thus NO. The Min proteins of E. coli and B. subtilis form bipolar gradients that inhibit Z ring formation most at the cell poles and least at the nascent division plane. This article will outline the molecular mechanisms behind Min function in E. coli and B. subtilis, and discuss distinct Z ring positioning systems in other bacterial species.

Nanomedical research in Australia and New Zealand

Although Australia and New Zealand have a combined population of less than 30 million, they have an active and interlinked community of nanomedical researchers. This report provides a synopsis and update on this network with a view to identifying the main topics of interest and their likely future trajectories. In addition, our report may also serve to alert others to opportunities for joint projects. Australian and New Zealand researchers are engaged in most of the possible nanomedical topics, but the majority of interest is focused on drug and nucleic acid delivery using nanoparticles or nanoporous constructs. There are, however, smaller programs directed at hyperthermal therapy and radiotherapy, various kinds of diagnostic tests and regenerative technologies.