Retargeted adenoviruses for radiation-guided gene delivery

The combination of radiation with radiosensitizing gene delivery or oncolytic viruses promises to provide an advantage that could improve the therapeutic results for glioblastoma. X-rays can induce significant molecular changes in cancer cells. We isolated the GIRLRG peptide that binds to radiation-inducible 78 kDa glucose-regulated protein (GRP78), which is overexpressed on the plasma membranes of irradiated cancer cells and tumor-associated microvascular endothelial cells. The goal of our study was to improve tumor-specific adenovirus-mediated gene delivery by selectively targeting the adenovirus binding to this radiation-inducible protein. We employed an adenoviral fiber replacement approach to conduct a study of the targeting utility of GRP78-binding peptide. We have developed fiber-modified adenoviruses encoding the GRP78-binding peptide inserted into the fiber-fibritin. We have evaluated the reporter gene expression of fiber-modified adenoviruses in vitro using a panel of glioma cells and a human D54MG tumor xenograft model. The obtained results demonstrated that employment of the GRP78-binding peptide resulted in increased gene expression in irradiated tumors following infection with fiber-modified adenoviruses, compared with untreated tumor cells. These studies demonstrate the feasibility of adenoviral retargeting using the GRP78-binding peptide that selectively recognizes tumor cells responding to radiation treatment

Can PPH3 be helpful to assess the discordant grade in primary and metastatic enteropancreatic neuroendocrine tumors?

Therapeutic strategy in neuroendocrine tumors (NETs) is based on histological characteristics of the primary tumor (PT), even in case of metastatic disease. Our aim was to compare the tumor grade between PT and their liver metastases (LM) in patients with enteropancreatic NETs. Forty-one patients treated for sporadic NETs (10 pancreatic, 31 intestinal) were included. All presented synchronous (35) or metachronous (6) LM. Tumor grade was evaluated for PT and LM according to the WHO classification, using Ki-67 labeling and mitotic count (MC) evaluated with or without phospho-histone H3 (PPH3). Tumor grade differed between primary and metastatic tumor in 16/41 patients (39 %), with an increase of grade in 13 of them (32 %). The median Ki-67, MC, and PPH3 in metastases were statistically higher than in PT (p = 0.0002, 0.02, and 0.01). In 17 of 65 cases tested with PPH3 (26 %), this antibody was more efficient in assessing the grade compared to the usual MC, and in 2/65 cases compared to the Ki-67. A better correlation was observed between Ki-67 and PPH3 (p = 0.0001) than between Ki-67 and MC without immunohistochemistry. There is a significant difference in tumor grade between primary and metastatic NETs, underlining the necessity of a systematic biopsy on LM for patient management. Moreover, PPH3 appears to be a powerful antibody to assess the MC and the tumor grade much more accurately when associated with Ki-67

Survival and prognostic factors analysis of 151 intestinal and pancreatic neuroendocrine tumors: a single center experience

Background: Intestinal and pancreatic neuroendocrine tumors (IP-NETs) are rare tumors with heterogeneous outcomes. The aim of our study was to determine the clinical, therapeutic and pathological factors which impact the overall survival (OS) in IP-NETs. Methods: All the patients diagnosed with IP-NETs at the Nantes University Hospital between October 1994 and October 2013 were retrospectively analysed. Patients with MEN-1 (Type 1 Multiple Endocrine Neoplasia) or Von Hippel-Lindau syndrome were excluded. Additionally, a prospective analysis of tumor grade (mitotic index and Ki67 index) was performed on tumor samples. OS was evaluated by Kaplan-Meier method and prognostic factors by log-rank test and Cox model. Results: The study included 151 patients. Median age was 60 (range, 14-81). Primary tumor was pancreatic in 86 patients (56.95%) and intestinal in 65 patients (43.05%). Tumors were metastatic (synchronous or metachronous) in 72 patients (47.7%). The median OS was 157 months. For all IP-NETs, age >65 years (P<0.0001), Ki67 >5% (P=0.03), synchronous metastases (P=0.016), primary tumor size >25 mm (P=0.03) and emergency surgery (P=0.007) were independent poor prognostic factors. Conclusions: In this large series of patients with IP-NET, age >65 years, Ki67 >5%, primary tumor size >25 mm, synchronous metastases and emergency surgery for acute complications have been identified as independent poor prognostic factors

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