Rb94 Gene ¦Ã-ray Irradiation Effects On K150 Cell Growth In Vivo, In Vitro Studies

Retinoblastoma gene is the first cloned human tumor suppressor gene, Rb gene deletions and mutations will lead to unlimited growth and reproduction of cells, thus resulting in tumorigenesis. So far, there are many anti-tumor gene therapy study reports about Rb as a target gene. A NH2-terminal truncated RB protein of 94 kDa (pRB94), lacking 112-amino acid residues, has been found to have greater efficacy than wild-type pRB in tumor suppression pRB94 was reported to remain in a hypophosphorylated state and showed a significantly greater half-life than the wild-type pRB. The present study investigates the combined effect of foreign retinoblastoma 94 gene and ionizing radiation on the growth of esophageal carcinoma cells K150, and provide a base for further clinical approach of Rb94 gene therapy for tumors.K150 cells was transfected by recombinant Rb94 gene adenovirus vector and irradiated by 6Gy Csγ-ray after transfection. The cohorts were divided into blank control, Ad-lacZ, Ad-Rb94, radiation and Ad-Rb94 combined with radiation. Cell growth, cell cycle, cell apoptosis and expression of retinoblastoma 94 gene of K150 cells were detected. K150 cell were treated in a nude mouse xenograft model with Ad-lacZ, Ad-Rb94, radiation and Ad-Rb94 combined with radiation or untreated as mock control. Tumor growth were evaluated.The growth of K150 cells transfected with Ad-Rb94, radiation and Ad-Rb94 combined with radiation group at 6 day after infection was all inhibited. The group of Ad-Rb94 combined with radiation resulted in greater inhibition of cells growth, reached 45.49%, compared with Ad-Rb94 infection (20.26%) and radiation group (35.11%) (P<0.05). Cells of G, phases and apoptosis of K150 cells for the Ad-Rb94 combined with radiation group were the highest, reached 73.4% and 15.7% respectively. The combination of Ad-Rb94 and radiation resulted in the greatest expression of retinoblastoma 94 gene, which was 1.87 fold and 2.92 fold of Ad-Rb94 infection and radiation respectively. Ad-Rb94 combined with radiation caused significant tumor regression compared with mock control. Ad-Rb94 gene transfer combined with radiation show synergism for the inhibition of esophageal cancer K150 cells growth.