Elucidation of the molecular mechanism underlying tumor-selective replication of the oncolytic adenovirus mutant ONYX-015

New hopes for the breast cancer treatment: perspectives on the oncolytic virus therapy

Oncolytic virus (OV) therapy has emerged as a promising frontier in cancer treatment, especially for solid tumours. While immunotherapies like immune checkpoint inhibitors and CAR-T cells have demonstrated impressive results, their limitations in inducing complete tumour regression have spurred researchers to explore new approaches targeting tumours resistant to current immunotherapies. OVs, both natural and genetically engineered, selectively replicate within cancer cells, inducing their lysis while sparing normal tissues. Recent advancements in clinical research and genetic engineering have enabled the development of targeted viruses that modify the tumour microenvironment, triggering anti-tumour immune responses and exhibiting synergistic effects with other cancer therapies. Several OVs have been studied for breast cancer treatment, including adenovirus, protoparvovirus, vaccinia virus, reovirus, and herpes simplex virus type I (HSV-1). These viruses have been modified or engineered to enhance their tumour-selective replication, reduce toxicity, and improve oncolytic properties.Newer generations of OVs, such as Oncoviron and Delta-24-RGD adenovirus, exhibit heightened replication selectivity and enhanced anticancer effects, particularly in breast cancer models. Clinical trials have explored the efficacy and safety of various OVs in treating different cancers, including melanoma, nasopharyngeal carcinoma, head and neck cancer, and gynecologic malignancies. Notably, Talimogene laherparepvec (T-VEC) and Oncorine have. been approved for advanced melanoma and nasopharyngeal carcinoma, respectively. However, adverse effects have been reported in some cases, including flu-like symptoms and rare instances of severe complications such as fistula formation. Although no OV has been approved specifically for breast cancer treatment, ongoing preclinical clinical trials focus on four groups of viruses. While mild adverse effects like low-grade fever and nausea have been observed, the effectiveness of OV monotherapy in breast cancer remains insufficient. Combination strategies integrating OVs with chemotherapy, radiotherapy, or immunotherapy, show promise in improving therapeutic outcomes. Oncolytic virus therapy holds substantial potential in breast cancer treatment, demonstrating safety in trials. Multi-approach strategies combining OVs with conventional therapies exhibit more promising therapeutic effects than monotherapy, signalling a hopeful future for OV-based breast cancer treatments.

Endoscopic ultrasound role in pancreatic adenocarcinoma treatment: A review focusing on technical success, safety and efficacy

The impressive technological advances in recent years have rapidly translated into the shift of endoscopic ultrasound (EUS) from diagnostic modality into an interventional and therapeutic tool. Despite the great advance in its diagnosis, the majority of pancreatic adenocarcinoma cases are inoperable when diagnosed, thus demanding alternative optional therapies. EUS has emerged as an easy, minimally invasive modality targeting this carcinoma with different interventions that have been reported recently. In this review we summarize the evolving role of interventional therapeutic EUS in pancreatic adenocarcinoma management.

Endoscopic ultrasound-fine needle injection for oncological therapy

The minimal invasiveness and precision of endoscopic ultrasound (EUS) has lead to both its widespread use as a diagnostic and staging modality for gastrointestinal and pancreaticobiliary malignancies, and to its expanding role as a therapeutic modality. EUS-guided celiac plexus neurolysis is now a well-accepted modality for palliation of pain in patients with pancreatic cancer. EUS-guided ablation, brachytherapy, fiducial marker placement, and antitumor agent injection have been described as methods of performing minimally invasive oncological therapy. EUS-fine needle injection may be performed as adjunctive, alternative, or palliative treatment. This review summarizes the studies to date that have described these methods. A literature search using the PubMed/MEDLINE databases was performed. While most published studies to date are limited with disappointing outcomes, the concept of a role of EUS in oncological therapy seems promising.

Direct therapeutic intervention for advanced pancreatic cancer

Currently, chemotherapy is an accredited, standard treatment for unresectable, advanced pancreatic cancer (PC). However, it has been still showed treatment-resistance and followed dismal prognosis in many cases. Therefore, some sort of new, additional treatments are needed for the better therapeutic results for advanced PC. According to the previous reports, it is obvious that interventional endoscopic ultrasonography (EUS) is a well-established, helpful and low-risky procedure in general. As the additional treatments of the conventional therapy for advanced PC, many therapeutic strategies, such as immunotherapies, molecular biological therapies, physiochemical therapies, radioactive therapies, using siRNA, using autophagy have been developing in recent years. Moreover, the efficacy of the other potential therapeutic targets for PC using EUS-fine needle injection, for example, intra-tumoral chemotherapeutic agents (paclitaxel, irinotecan), several ablative energies (radiofrequency ablation and cryothermal treatment, neodymium-doped yttrium aluminum garnet laser, high-intensity focused ultrasound), etc., has already been showed in animal models. Delivering these promising treatments reliably inside tumor, interventional EUS may probably be indispensable existence for the treatment of locally advanced PC in near future.

Viruses, gene therapy and stem cells for the treatment of human glioma

Cancer gene therapy is based on the transfer of genetic material to cancer cells to modify a normal or abnormal cellular function, or to induce cell death. Modified viruses or stem cells have been used as carriers to transfer the genetic material to cancer cells avoiding trafficking through normal cells. However, although the current vectors have been successful in delivering genes in vitro and in vivo, little has been achieved with human cerebral gliomas. Poor transduction efficiency of viruses in human glioma cells and limited spread and distribution to the tumor limits our current expectations for successful gene therapy of central nervous system cancer until and if effective transfer vehicles are available. Nevertheless, continuing research in better vector development may overcome these limitations and offer a therapeutic advantage over the standard therapies for glioma.

Endoscopic ultrasound-guided intratumoural therapy for pancreatic cancer

Pancreatic cancer is the second most frequent gastrointestinal malignancy and carries a dismal prognosis. The current standard of care includes resection, if possible, as well as systemic chemoradiation therapy. Endoscopic ultrasound (EUS) is an established technique for the diagnosis and staging of pancreatic adenocarcinoma. Interventional EUS via fine needle injection (FNI) for the treatment of pancreatic cancer is a rapidly expanding field. The present article reviews the up-to-date developments in EUS FNI for intratumoural pancreatic cancer therapy, including antitumoural agents, immunotherapy, ablative techniques and new delivery systems. The therapeutic modalities discussed are currently under development and will hopefully reach clinical practice if benefit is demonstrated through clinical trials. EUS FNI may be an exciting new technique for the delivery of desperately needed novel therapies for pancreatic cancer.

Myxoma virus and oncolytic virotherapy: a new biologic weapon in the war against cancer

Oncolytic virotherapy is an innovative alternative to more conventional cancer therapies. The ability of some viruses to specifically target and kill malignant cancerous cells while leaving normal tissue unscathed has opened a large repertoire of new and selective cancer killing therapeutic candidates. Poxviruses, such as vaccinia virus, have a long history of use in humans as live vaccines and have more recently been studied as potential platforms for delivery of immunotherapeutics and attenuated variants of vaccinia have been explored as oncolytic candidates. In contrast, the poxvirus myxoma virus is a novel oncolytic candidate that has no history of use in humans directly, as it has a distinct and absolute host species tropism to lagomorphs (rabbits). Myxoma virus has been recently shown to be able to also selectively infect and kill human tumor cells, a unique tropism that is linked to dysregulated intracellular signalling pathways found in the majority of human cancers. This review outlines the existing knowledge on the tropism of myxoma virus for human cancer cells, as well as preclinical data exhibiting its ability to infect and clear tumors in animal models of cancer. This is an exciting new therapeutic option for treating cancer, and myxoma virus joins a growing group of oncolytic virus candidates that are being developed as a new class of cancer therapies in man.

p53 gene in treatment of hepatic carcinoma: status quo

Hepatocellular carcinoma (HCC) is one of the 10 most common cancers worldwide. There is no ideal treatment for HCC yet and many researchers are trying to improve the effects of treatment by changing therapeutic strategies. As the majority of human cancers seem to exhibit either abnormal p53 gene or disrupted p53 gene activation pathways, intervention to restore wild-type p53 (wt-p53) activities is an attractive anti-cancer therapy including HCC. Abnormalities of p53 are also considered a predisposition factor for hepatocarcinogenesis. p53 is frequently mutated in HCC. Most HCCs have defects in the p53-mediated apoptotic pathway although they carry wt-p53. High expression of p53 in vivo may exert therapeutic effects on HCC in two aspects: (1) High expression of exogenous p53 protein induces apoptosis of tumor cells by inhibiting proliferation of cells through several biologic pathways and (2) Exogenous p53 renders HCC more sensitive to some chemotherapeutic agents. Several approaches have been designed for the treatment of HCC via the p53 pathway by restoring the tumor suppression function from inactivation, rescuing the mutated p53 gene from instability, or delivering therapeutic exogenous p53. Products with p53 status as the target have been studied extensively in vitro and in vivo. This review elaborates some therapeutic mechanisms and advances in using recombinant human adenovirus p53 and oncolytic virus products for the treatment of HCC.

The highly attenuated vaccinia virus strain modified virus Ankara induces apoptosis in melanoma cells and allows bystander dendritic cells to generate a potent anti-tumoral immunity

Vaccinia virus (VV) has been tested as oncolytic virus against malignant melanoma in clinical trials for more than 40 years. Until now, mainly strains comparable to viral strains used for smallpox vaccination have been probed for anti-tumoral therapy. We have shown recently that the wild-type strain Western Reserve (WR) can interfere with crucial functions of monocyte-derived dendritic cells (DCs). Our aim was to examine whether viral immune evasion mechanisms might be responsible for the ineffectiveness of WR-based vaccination strategies and whether the highly attenuated strain modified virus Ankara (MVA) differs from WR with respect to its possible immunostimulatory capacity after intratumoral injection. Using in vitro experiments, we compared the effect of both strains on melanoma cells and on local bystander DCs. We found that both VV-strains infected melanoma cells efficiently and caused disintegration of the actin cytoskeleton, as shown by fluorescence microscopy. In addition, both VV-strains caused apoptotic cell death in melanoma cells after infection. In contrast to MVA, WR underwent a complete viral replication cycle in melanoma cells. Bystander DCs were consecutively infected by newly generated WR virions and lost their capacity to induce allogeneic T cell proliferation. DCs in contact with MVA-infected melanoma cells retained their capacity to induce T cell proliferation. Immature DCs were capable of phagocytosing MVA-infected melanoma cells. Priming of autologous CD8(+) T cells by DCs that had phagocytosed MVA-infected, MelanA positive melanoma cells resulted in the induction of T cell clones specifically reactive against the model antigen MelanA as shown by enzyme-linked immunospot (ELISPOT) analysis. We conclude that the clinical trials with oncolytic wild-type VV failed probably because of suppression of bystander DCs and consecutive suppression of T cell-mediated anti-melanoma immunity. The attenuated VV-strain MVA facilitates the generation of tumour associated antigen (TAA)-specific T cell response as it is oncolytic for melanoma cells, but non-toxic for DC, and should be a promising candidate for intralesional metastatic melanoma therapy.