Alan Wei-Shun Tseng1,2, Chiachen Chen1,3, Mary B Breslin1,3,4, Michael S Lan5,6,7,8. 1. The Research Institute for Children, Children's Hospital, 200 Henry Clay Avenue, New Orleans, LA, 70118, USA. 2. Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, New Orleans, LA, 70112, USA. 3. Laboratory of Diana Helis Henry Medical Research Foundation, New Orleans, LA, 70119, USA. 4. Department of Pediatrics, Louisiana State University Health Sciences Center, New Orleans, LA, 70112, USA. 5. The Research Institute for Children, Children's Hospital, 200 Henry Clay Avenue, New Orleans, LA, 70118, USA. mlan@chnola-research.org. 6. Laboratory of Diana Helis Henry Medical Research Foundation, New Orleans, LA, 70119, USA. mlan@chnola-research.org. 7. Department of Pediatrics, Louisiana State University Health Sciences Center, New Orleans, LA, 70112, USA. mlan@chnola-research.org. 8. Department of Genetics, Louisiana State University Health Sciences Center, New Orleans, LA, 70112, USA. mlan@chnola-research.org.
Abstract
BACKGROUND: Insulinomas are the most common type of neuroendocrine (NE) pancreatic islet tumors. Patients with insulinomas may develop complications associated with hyperinsulinemia. To increase the treatment options for insulinoma patients, we have tested a conditionally replicating adenovirus that has been engineered in such a way that it can specifically express therapeutic genes in NE tumors. METHODS: We used a promoter-specific adenoviral vector delivery system that is regulated by an INSM1 (insulinoma-associated-1) promoter, which is silent in normal adult tissues but active in developing NE cells and tumors. Through a series of modifications, using an insulator (HS4) and neuron-restrictive silencer elements (NRSEs), an oncolytic adenoviral vector was generated that retains tumor specificity and drives the expression of a mutated adenovirus E1A gene (Δ24E1A) and the herpes simplex virus thymidine kinase (HSV-tk) gene. The efficacy of this vector was tested in insulinoma-derived MIN, RIN, βTC-1 and pancreatic (Panc-1) cells using in vitro cell survival and in vivo tumor growth assays. RESULTS: Using in vitro insulinoma-derived cell lines and an in vivo subcutaneous mouse tumor model we found that the INSM1 promoter-driven viruses were able to replicate specifically in INSM1-positive cells. INSM1-specific HSV-tk expression in combination with ganciclovir treatment resulted in dose-dependent tumor cell killing, leaving INSM1-negative cells unharmed. When we combined the INSM1-promoter driven HSV-tk with Δ24E1A and INSM1p-HSV-tk (K5) viruses, we found that the co-infected insulinoma-derived cells expressed higher levels of HSV-tk and exhibited more efficient tumor suppression than cells infected with INSM1p-HSV-tk virus alone. CONCLUSIONS: INSM1 promoter-driven conditionally replicating adenoviruses may serve as a new tool for the treatment of insulinoma and may provide clinicians with additional options to combat this disease.
BACKGROUND:Insulinomas are the most common type of neuroendocrine (NE) pancreatic islet tumors. Patients with insulinomas may develop complications associated with hyperinsulinemia. To increase the treatment options for insulinomapatients, we have tested a conditionally replicating adenovirus that has been engineered in such a way that it can specifically express therapeutic genes in NE tumors. METHODS: We used a promoter-specific adenoviral vector delivery system that is regulated by an INSM1 (insulinoma-associated-1) promoter, which is silent in normal adult tissues but active in developing NE cells and tumors. Through a series of modifications, using an insulator (HS4) and neuron-restrictive silencer elements (NRSEs), an oncolytic adenoviral vector was generated that retains tumor specificity and drives the expression of a mutated adenovirus E1A gene (Δ24E1A) and the herpes simplex virus thymidine kinase (HSV-tk) gene. The efficacy of this vector was tested in insulinoma-derived MIN, RIN, βTC-1 and pancreatic (Panc-1) cells using in vitro cell survival and in vivo tumor growth assays. RESULTS: Using in vitro insulinoma-derived cell lines and an in vivo subcutaneous mousetumor model we found that the INSM1 promoter-driven viruses were able to replicate specifically in INSM1-positive cells. INSM1-specific HSV-tk expression in combination with ganciclovir treatment resulted in dose-dependent tumor cell killing, leaving INSM1-negative cells unharmed. When we combined the INSM1-promoter driven HSV-tk with Δ24E1A and INSM1p-HSV-tk (K5) viruses, we found that the co-infected insulinoma-derived cells expressed higher levels of HSV-tk and exhibited more efficient tumor suppression than cells infected with INSM1p-HSV-tk virus alone. CONCLUSIONS:INSM1 promoter-driven conditionally replicating adenoviruses may serve as a new tool for the treatment of insulinoma and may provide clinicians with additional options to combat this disease.
Authors: Mathias S Gierl; Nikolaos Karoulias; Hagen Wende; Michael Strehle; Carmen Birchmeier Journal: Genes Dev Date: 2006-09-01 Impact factor: 11.361
Authors: Hong-Wei Wang; Mary B Breslin; Chiachen Chen; Victoria Akerstrom; Qiu Zhong; Michael S Lan Journal: Hum Gene Ther Date: 2009-11 Impact factor: 5.695