Analysis of ICAM-1 Expression on Bladder Carcinoma Cell Lines and Infectivity and Oncolysis by Coxsackie Virus A21.

Oncolytic viruses are biological agents which can easily be delivered at high doses directly to the bladder through a catheter (intravesical), with low risk of systemic uptake and toxicity. To date, a number of viruses have been delivered intravesically in patients and in murine models with bladder cancer and antitumour effects demonstrated. Here, we describe in vitro methods to evaluate Coxsackie virus, CVA21, as an oncolytic virus for the treatment of human bladder cancer by determining the susceptibility of bladder cancer cell lines expressing differing levels of ICAM-1 surface receptor to CVA21.

A Comprehensive Review of the Current and Future Role of the Microbiome in Pancreatic Ductal Adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is expected to become the second most common cause of cancer death in the USA by 2030, yet progress continues to lag behind that of other cancers, with only 9% of patients surviving beyond 5 years. Long-term survivorship of PDAC and improving survival has, until recently, escaped our understanding. One recent frontier in the cancer field is the microbiome. The microbiome collectively refers to the extensive community of bacteria and fungi that colonise us. It is estimated that there is one to ten prokaryotic cells for each human somatic cell, yet, the significance of this community in health and disease has, until recently, been overlooked. This review examines the role of the microbiome in PDAC and how it may alter survival outcomes. We evaluate the possibility of employing microbiomic signatures as biomarkers of PDAC. Ultimately this review analyses whether the microbiome may be amenable to targeting and consequently altering the natural history of PDAC.

Synergistic effects of oncolytic reovirus and docetaxel chemotherapy in prostate cancer.

BACKGROUND: Reovirus type 3 Dearing (T3D) has demonstrated oncolytic activity in vitro, in in vivo murine models and in early clinical trials. However the true potential of oncolytic viruses may only be realized fully in combination with other modalities such as chemotherapy, targeted therapy and radiotherapy. In this study, we examine the oncolytic activity of reovirus T3D and chemotherapeutic agents against human prostate cancer cell lines, with particular focus on the highly metastatic cell line PC3 and the chemotherapeutic agent docetaxel. Docetaxel is the standard of care for metastatic prostate cancer and acts by disrupting the normal process of microtubule assembly and disassembly. Reoviruses have been shown to associate with microtubules and may require this association for efficient viral replication. METHODS: The effects of reovirus and chemotherapy on in vitro cytotoxicity were investigated in PC3 and Du 145 cells and the interactions between agents were assessed by combination index analysis. An Annexin V/propidium iodide fluorescence-activated cell sorting-based assay was used to determine mode of cell death. The effects of reovirus and docetaxel administered as single agent or combination therapy were tested in vivo in a murine model. The effects of docetaxel and reovirus, alone and together, on microtubule stabilisation were investigated by Western blot analysis. RESULTS: Variable degrees of synergistic cytotoxicity were observed in PC3 and Du 145 cells exposed to live reovirus and several chemotherapy agents. Combination of reovirus infection with docetaxel exposure led to increased late apoptotic/necrotic cell populations. Reovirus/docetaxel combined therapy led to reduced tumour growth and increased survival in a PC3 tumour bearing mouse model. Microtubule stabilization was enhanced in PC3 cells treated with reovirus/docetaxel combined therapy compared to other reovirus/chemotherapy combinations. CONCLUSIONS: The co-administration of a variety of chemotherapeutic agents with live reovirus was able to enhance cytotoxicity synergistically in vitro. The combination of docetaxel with reovirus also delayed tumour growth and improved survival in vivo. Enhanced microtubule stabilisation following this combination treatment may, in part, explain the mechanism of synergy. These results provide evidence to support the ongoing clinical trials using these agents.

Emergence of potential biomarkers of response to anti-angiogenic anti-tumour agents.

Anti-angiogenic agents targeting tumour vasculature have an established place in clinical practice, and new data are constantly emerging. However, despite rapid clinical uptake, a very large number of questions regarding these agents remain unanswered. One of the main hurdles in clinical practice is lack of accurate and feasible ways of assessing response to drug beyond tumour reduction on conventional imaging. This review summarises recent developments in the field of biomarkers of response to anti-VEGF drugs.

Oncolytic Immunotherapy for Bladder Cancer Using Coxsackie A21 Virus: Using a Bladder Tumor Precision-Cut Slice Model System to Assess Viral Efficacy.

Oncolytic viruses are anticancer agents that selectively target and kill cancer cells by direct lysis, while at the same time stimulating a tumor antigen-specific adaptive immune response. These promising therapeutic agents target multiple cancers and have already proven to be an effective treatment option for solid malignancies. One such agent, T-Vec (Talimogene laherparepvec) has been licensed and is in routine clinical use for treatment of malignant melanoma.Non-muscle invasive bladder cancer (NMIBC) is an ideal potential target for oncolytic immunotherapy as locally instilled live biological therapy using Bacille Calmette-Guerin (BCG) is already well established in the clinical setting. Coxsackievirus A21 (CVA21) is a novel intercellular adhesion molecule-1 (ICAM-1)-targeted immunotherapeutic virus. We have investigated CVA21-induced cytotoxicity in a panel of human bladder cancer cell lines, revealing a range of sensitivities largely correlating with expression of the viral receptor ICAM-1. CVA21 in combination with low doses of mitomycin-C enhanced CVA21 viral replication and oncolysis by increasing surface expression levels of ICAM-1. In addition to cell lines and an animal model a key component of our studies into oncolytic immunotherapy for bladder cancer was the use of a bladder tumor precision slice preclinical model system which represents tumor architecture, heterogeneity, and the complexity of a tumor in vitro. Results seen in cell lines were reflected in the tumor slice model whereby levels of virus protein expression and induction of apoptosis were enhanced with prior exposure to mitomycin-C. In this chapter we demonstrate the utility of the precision cut tumor slice model as a unique organotypic model to test oncolytic viruses. We will describe how to prepare and slice the tumor using a vibrating microtome together with the optimum culture and conditions for treatment.

Synergistic antitumour effects of rapamycin and oncolytic reovirus.

There are currently numerous oncolytic viruses undergoing clinical trial evaluation in cancer patients and one agent, Talimogene laherparepvec, has been approved for the treatment of malignant melanoma. This progress highlights the huge clinical potential of this treatment modality, and the focus is now combining these agents with conventional anticancer treatments or agents that enhance viral replication, and thereby oncolysis, in the tumour microenvironment. We evaluated the combination of reovirus with rapamycin in B16F10 cell, a murine model of malignant melanoma, based on potential mechanisms by which mTOR inhibitors might enhance viral oncolysis. Rapamycin was not immunomodulatory in that it had no effect on the generation of an antireovirus-neutralising antibody response in C57/black 6 mice. The cell cycle effects of reovirus (increase G0/G1 fraction) were unaffected by concomitant or sequential exposure of rapamycin. However, rapamycin attenuated viral replication if given prior or concomitantly with reovirus and similarly reduced reovirus-induced apoptotic cell death Annexin V/PI and caspase 3/7 activation studies. We found clear evidence of synergistic antitumour effects of the combination both in vitro and in vivo, which was sequence dependent only in the in vitro setting. In conclusion, we have demonstrated synergistic antitumour efficacy of reovirus and rapamycin combination.

Cancer immunotherapy via combining oncolytic virotherapy with chemotherapy: recent advances.

Oncolytic viruses are multifunctional anticancer agents with huge clinical potential, and have recently passed the randomized Phase III clinical trial hurdle. Both wild-type and engineered viruses have been selected for targeting of specific cancers, to elicit cytotoxicity, and also to generate antitumor immunity. Single-agent oncolytic virotherapy treatments have resulted in modest effects in the clinic. There is increasing interest in their combination with cytotoxic agents, radiotherapy and immune-checkpoint inhibitors. Similarly to oncolytic viruses, the benefits of chemotherapeutic agents may be that they induce systemic antitumor immunity through the induction of immunogenic cell death of cancer cells. Combining these two treatment modalities has to date resulted in significant potential in vitro and in vivo synergies through various mechanisms without any apparent additional toxicities. Chemotherapy has been and will continue to be integral to the management of advanced cancers. This review therefore focuses on the potential for a number of common cytotoxic agents to be combined with clinically relevant oncolytic viruses. In many cases, this combined approach has already advanced to the clinical trial arena.

Adenoviral strategies for the gene therapy of cancer.

Despite slow clinical progress, efforts to develop specific nontoxic cancer gene therapies are increasing exponentially. Adenoviral vectors are one of the most popular vehicles for gene transfer currently being used in worldwide clinical trials for cancer. Over the past decade our knowledge of the adenoviral life cycle together with the discovery of novel tumor antigens has permitted the targeting of adenoviral vectors to specific tumors. Targeting adenoviral vectors to tumors is crucial for their use in clinical applications in order to allow for systemic administration and the use of reduced vector doses. In addition, novel approaches to tumor killing have also been explored, which will have greater potency and selectivity than currently available treatments such as chemotherapy or radiation. This review discusses the basic concepts behind the use of adenoviral vectors for cancer gene therapy and their potential for clinical application, as well as ongoing and completed clinical trials.

Prostate cancer vaccines.

In 2010, the US FDA approved the first therapeutic cancer vaccine for the treatment of castration refractory prostate cancer - sipuleucel-T. Prostate cancer is an ideal model for cancer vaccine development based on the ready demonstration of humoral and cellular immunity to a range of cancer antigens as well as often slow progression which means that patients who are otherwise well may have a radiologically evaluable minor progression, after conventional treatment and can undergo vaccine therapy over sufficient periods of time, so as to allow the generation of a robust antitumor response. The association of prostate cancer with one of the few serum cancer biomarkers in general use has also allowed assessment of response and risk stratification of patients. In this review, we will examine key aspects of the evolution of prostate cancer vaccines, which provides an accurate prototype for other cancers, and the challenges we face.

Prognostic significance of erythropoietin expression in human renal cell carcinoma.

OBJECTIVES: To investigate, in a retrospective study, the expression of erythropoietin (Epo) in human renal cell carcinoma (RCC) and its correlation with overall survival, as Epo (an haematopoietic cytokine that regulates the production of red blood cells), with its receptor, was recently localized in non-haematopoietic tissues, e.g. liver, uterus, central nervous system, vascular endothelial cells and solid tumours. PATIENTS AND METHODS: We used data from 113 patients who had radical nephrectomy for RCC between 1990 and 2000, taking sections from formalin-fixed and paraffin wax-embedded tissue blocks. The association between Epo staining and the patients' characteristics was assessed by either chi-squared tests (for categorical variables) or two-sample independent t-tests (for continuous variables). RESULTS: Tissue from 37 patients (33%) was positive for cytoplasmic Epo expression; 76 (67%) samples were negative. Univariate hazard ratio analysis confirmed that those with positive Epo staining were more than twice as likely to die as those with negative staining (hazard ratio 2.34, 95% confidence interval 1.27-4.3). CONCLUSION: This study shows that the expression of Epo in RCC is adversely associated with overall survival. This is the first report of such an association, and might be explained by the loss of Von Hippel-Lindau protein function in clear cell RCC. The expression of Epo might have potential use in clinical trials when stratifying high-risk patients for adjuvant therapy after nephrectomy.

Antitumor effects of aminobisphosphonates on renal cell carcinoma cell lines.

PURPOSE: Bisphosphonates are established as a supportive therapy for a number of malignancies that metastasize to bone. Previous reports have also suggested potent antitumor and anti-angiogenic properties. We investigated the in vitro activity of the 2 aminobisphosphonates pamidronate (Faulding Pharmaceuticals, Paramus, New Jersey) and zoledronic acid (Novartis, Basel, Switzerland) on the growth and survival of the 3 renal cell carcinoma cell lines Caki-2, 769-P (American Type Culture Collection, Manassas, Virginia) and D69581. MATERIALS AND METHODS: Cell lines were exposed to bisphosphonates in vitro and evaluated by MTS (3-(4,5-dimethylahiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay and cell cycle analysis. Mechanisms of apoptotic cell death were investigated by ApoDIRECT assay (BioVision, Mountain View, California) and Kinetworks analysis. RESULTS: Zoledronic acid was consistently more potent than pamidronate for inducing apoptotic cell death. Zoledronic acid was capable of overcoming resistance to pamidronate in 1 cell line. Although it was ultimately less potent, the inhibitory effects of pamidronate appeared earlier than those of zoledronic acid. The pro-apoptotic effect of zoledronic acid was achieved through nonmitochondrial pathways and it was associated with the activation of caspase 6 and 3, and poly adenosine diphosphate-ribosyltransferase polymerase cleavage. Furthermore, we observed a marked decrease in and intracellular distribution of MSH2, a protein involved in DNA mismatch repair, as well as evidence of a greater cellular response to zoledronic acid as increased expression of superoxide dismutase. CONCLUSIONS: These findings add further support to the clinical use of aminobisphosphonates, particularly zoledronic acid, in patients with renal cell carcinoma with disease metastatic to bone.