Yann Touchefeu

Oncolytic viruses in radiation oncology

Oncolytic viruses are investigational cancer treatments. They are currently being assessed as single agents or in combination with standard therapies such as external beam radiotherapy - a DNA damaging agent that is a standard of care for many tumour types. Preclinical data indicate that combinations of oncolytic viruses and radiation therapy are promising, showing additional or synergistic antitumour effects in in vitro and in vivo studies. This interaction has the potential to be multifaceted: viruses may act as radiosensitizing agents, but radiation may also enhance viral oncolysis by increasing viral uptake, replication, gene expression and cell death (apoptosis, autophagy or necrosis) in irradiated cells. Phase I and II clinical trials investigating combinations of viruses and radiation therapy have been completed, paving the way for ongoing phase III studies. The aim of this review is to focus on the therapeutic potential of these combinations and to highlight their mechanistic bases, with particular emphasis on the role of the DNA damage response.

Endoscopic ultrasound-guided fine-needle aspiration for the diagnosis of solid pancreatic masses: the impact on patient-management strategy

Background  Endoscopic ultrasound‐guided fine‐needle aspiration (EUS‐FNA) is a safe and accurate technique for diagnosing pancreatic cancer. However, its impact for management of these patients is poorly investigated.

Review article: gene therapy, recent developments and future prospects in gastrointestinal oncology

Aliment Pharmacol Ther 2010; 32: 953–968

Synergistic cytotoxicity of radiation and oncolytic Lister strain vaccinia in V600D/E BRAF mutant melanoma depends on JNK and TNF-α signaling

Melanoma is an aggressive skin cancer that carries an extremely poor prognosis when local invasion, nodal spread or systemic metastasis has occurred. Recent advances in melanoma biology have revealed that RAS-RAF-MEK-ERK signaling has a pivotal role in governing disease progression and treatment resistance. Proof-of-concept clinical studies have shown that direct BRAF inhibition yields impressive responses in advanced disease but these are short-lived as treatment resistance rapidly emerges. Therefore, there is a pressing need to develop new targeted strategies for BRAF mutant melanoma. As such, oncolytic viruses represent a promising cancer-specific approach with significant activity in melanoma. This study investigated interactions between genetically-modified vaccinia virus (GLV-1h68) and radiotherapy in melanoma cell lines with BRAF mutant, Ras mutant or wild-type genotype. Preclinical studies revealed that GLV-1h68 combined with radiotherapy significantly increased cytotoxicity and apoptosis relative to either single agent in V600DBRAF/V600EBRAF mutant melanoma in vitro and in vivo. The mechanism of enhanced cytotoxicity with GLV-1h68/radiation (RT) was independent of viral replication and due to attenuation of JNK, p38 and ERK MAPK phosphorylation specifically in BRAF mutant cells. Further studies showed that JNK pathway inhibition sensitized BRAF mutant cells to GLV-1h68-mediated cell death, mimicking the effect of RT. GLV-1h68 infection activated MAPK signaling in V600DBRAF/V600EBRAF mutant cell lines and this was associated with TNF-α secretion which, in turn, provided a prosurvival signal. Combination GLV-1h68/RT (or GLV-1h68/JNK inhibition) caused abrogation of TNF-α secretion. These data provide a strong rationale for combining GLV-1h68 with irradiation in V600D/EBRAF mutant tumors.

Radiovirotherapy: Principles and Prospects in Oncology

Radiovirotherapy is defined as the use of viruses to deliver radioisotopic treatment into infected cells. Oncolytic viruses are able to selectively target and kill cancer cells. The combination of oncolytic viruses and radiation therapies can have synergistic antitumour properties. Viruses may act as radiosensitizers, and radiations can increase viral oncolytic properties. The combination of oncolytic viruses with a virally-directed radioisotope therapy is an innovative method to combine viruses and radiation therapy, selectively within the tumour cells. The sodium/iodide symporter (NIS) is the main transgene that has been studied for this approach. NIS can mediate the uptake of isotopes of iodine and technetium 99m for in vivo gene expression imaging and therapy. This review highlights the principles of radiovirotherapy, and its recent progress. Better understanding of the regulation of NIS opens up pathways by which to potentiate the functional expression of NIS. In terms of the therapeutic isotope, Iodine-131 has been most frequently studied but other isotopes (astatine- 211, rhenium-188) are of growing interest. Oncolytic viruses are able to infect selectively and replicate in cancer cells and promising early phase clinical trials have been recently published. Their development allows a better selectivity of viral infection and adds a virus-specific cytotoxicity to the therapeutic approach. Active research into strategies such as immunosuppressive treatment and cell-based carrier systems is seeking to circumvent the host antiviral immune response and, thus, increase the potential for systemic delivery. Finally, other anticancer therapies such as chemotherapy and external beam radiotherapy may have a synergistic effect with radiovirotherapy and such combinatorial approaches offering the prospect of accelerated translation into clinical studies.

Oncolytic Vaccinia virus and radiotherapy in head and neck cancer

OBJECTIVE Oncolytic forms of attenuated Vaccinia virus are now in clinical development, assessing the compatibility of this novel treatment with radiotherapy may reveal exploitable synergistic relationships. MATERIALS AND METHODS In vitro analyses of cell killing, cell cycle effects and caspase activation were carried out on HN3, HN5, CAL27, Detroit, SIHN5B, and PJ41 cells. In vivo studies of the virus and X-radiation were performed on H&N xenografts in CD1 nude mice. RESULTS Cell killing in vitro was demonstrated to be dose- and time-dependent. Infection causes an increase in S-phase and sub-G1 cells. A dose dependent increase in active caspase-3 indicated induction of apoptosis. Xenografts injected with Vaccinia stabilised and frequently completely regressed. Combination with radiation generated additional cell death, induction of caspase activity and in vivo further improved long term regression rates. CONCLUSIONS These data support continued exploration of this therapy combination and indicates potential for clinical trials in head and neck cancer.

Optimising measles virus-guided radiovirotherapy with external beam radiotherapy and specific checkpoint kinase 1 inhibition.

BACKGROUND AND PURPOSE We previously reported a therapeutic strategy comprising replication-defective NIS-expressing adenovirus combined with radioiodide, external beam radiotherapy (EBRT) and DNA repair inhibition. We have now evaluated NIS-expressing oncolytic measles virus (MV-NIS) combined with NIS-guided radioiodide, EBRT and specific checkpoint kinase 1 (Chk1) inhibition in head and neck and colorectal models. MATERIALS AND METHODS Anti-proliferative/cytotoxic effects of individual agents and their combinations were measured by MTS, clonogenic and Western analysis. Viral gene expression was measured by radioisotope uptake and replication by one-step growth curves. Potential synergistic interactions were tested in vitro by Bliss independence analysis and in in vivo therapeutic studies. RESULTS EBRT and MV-NIS were synergistic in vitro. Furthermore, EBRT increased NIS expression in infected cells. SAR-020106 was synergistic with EBRT, but also with MV-NIS in HN5 cells. MV-NIS mediated (131)I-induced cytotoxicity in HN5 and HCT116 cells and, in the latter, this was enhanced by SAR-020106. In vivo studies confirmed that MV-NIS, EBRT and Chk1 inhibition were effective in HCT116 xenografts. The quadruplet regimen of MV-NIS, virally-directed (131)I, EBRT and SAR-020106 had significant anti-tumour activity in HCT116 xenografts. CONCLUSION This study strongly supports translational and clinical research on MV-NIS combined with radiation therapy and radiosensitising agents.

Hamartomatous Tumors in the Gastrointestinal Tract

Background: Digestive hamartomatous polyps are a rare entity. They may be sporadic (solitary Peutz-Jeghers polyp or solitary juvenile polyp) or reveal genetic predisposition like Peutz-Jeghers syndrome, juvenile polyposis or Cowden disease. Summary: Diagnosis is based on personal and family history and on clinical data including physical signs (in particular dermatological), endoscopic findings (the number of polyps) and histological features of the polyps. The risk of complications and of digestive and extra-digestive cancers may be high, especially in case of genetic predisposition syndromes, and requires multidisciplinary management of the patients (oncogenetic counseling, gastroenterologist, pathologist, dermatologist, gynecologist and endocrinologist). Endoscopic evaluation is very helpful to establish the current situation, to perform polypectomy and to allow for good histological examination of the polyps, whose degeneration has been exceptionally described. The recent development of new molecular techniques (next-generation DNA sequencing) allows for rapid multiple gene sequencing and facilitates diagnosis. Key Message: Discovery of a hamartomatous polyp requires a rigorous work-up which should be performed by a multidisciplinary team, including a genetic oncologist, experienced in this pathology. Practical Implications: The diagnostic procedure in hamartomatous polyps should be based on the number of polyps identified during endoscopy (solitary versus multiple) and on their histological characteristics. The clinical examination must search for mucosal and skin lesions. If a polyposis syndrome is identified, oncogenetic consultation is necessary in order to define screening modalities for family members, aiming at preventing cancer development. Endoscopic resection (polypectomy) of the lesions may prevent complications like bleeding and degeneration and also diminish the risk of surgery and subsequent short bowel syndrome.

Short article: Evaluation of O6-methylguanine-DNA methyltransferase as a predicting factor of response to temozolomide-based chemotherapy in well-differentiated metastatic pancreatic neuroendocrine tumors

Objective Temozolomide (TMZ) is an alkylating agent frequently used in well-differentiated metastatic pancreatic neuroendocrine tumors (PNETs) with very variable responses. O6-methylguanine-DNA methyltransferase (MGMT) is a DNA repair enzyme whose loss of expression has been suggested to be predictive of response to TMZ in various human tumors. We evaluated the predictive value of MGMT status, assessed by immunohistochemistry (IHC) and methylation-specific PCR (MS-PCR), in well-differentiated metastatic PNETs treated by a TMZ-based chemotherapy. Patients and methods All patients with metastatic PNETs treated with TMZ-based chemotherapy between 2010 and 2016 in two academic centers, for whom the tumor samples were available, were included. Clinical data were collected and the MGMT status of the tumors was analyzed using MS-PCR and IHC. Results Twenty-two patients (nine men, median age 61 years) were included. The loss of MGMT protein expression detected by IHC was observed in 13 (59%) patients and MGMT promoter hypermethylation was detected by MS-PCR in three (15%) out of 20 interpretable cases. MGMT status did not correlate significantly with the best radiological response according to the Response Evaluation Criteria In Solid Tumors criteria or with progression-free survival. There was no correlation between MGMT protein expression and MGMT gene promoter methylation. Conclusion These results indicate that a deficient MGMT status in PNETs, determined by loss of protein expression in IHC or by the presence of MGMT gene promoter methylation measured by MS-PCR, is not associated with a better response to TMZ-based chemotherapy and cannot be used as a predictive marker to lead treatment decisions.

Gemcitabine plus platinum-based chemotherapy for first-line treatment of hepatocholangiocarcinoma: an AGEO French multicentre retrospective study

Background:Hepatocholangiocarcinoma (cHCC-ICC) is a rare liver tumour for which no data on chemosensitivity exist. The aims of this multicentre study were to evaluate overall survival (OS), progression-free survival (PFS), and prognostic factors in cHCC-ICC treated by gemcitabine plus platinum as first-line.Methods:Unresectable cHCC-ICC treated by gemcitabine plus platinum-based chemotherapy between 2008 and 2017 were retrospectively analysed. Diagnosis was based on histology or, in case of ICC or HCC histology, on discordant computerised tomography scan enhancement patterns associated with discordant serum tumour marker elevation suggesting the alternative tumour. OS and PFS were evaluated by Kaplan–Meier method and prognostic factors by Log-rank test and Cox model.Results:Among 30 patients included, cHCC-ICC was histologically proven in 22 (73.3%). 18 (60%) received gemcitabine plus oxaliplatin (GEMOX), 9 (30%) GEMOX plus bevacizumab, and 3 (10%) gemcitabine plus cisplatin. RECIST criteria were reported in 28 patients: 8 (28.6%) showed partial response, 14 (50%) stable disease, and 6 (21.4%) tumour progression at first evaluation. Median PFS and OS were 9.0 and 16.2 months, respectively. Serum bilirubin ⩾30 μmol l−1 (P=0.001) and positive serology for HBV and/or HCV (P=0.014) were independent poor prognostic factors for OS.Conclusions:Gemcitabine plus platinum-based chemotherapy is effective as first-line for advanced cHCC-ICC.