ABSTRACT
<p><b>BACKGROUND</b>Pancreatic cancer is a highly malignant tumor affecting an ever increasing number of patients with a mean 5-year survival rate below 4%. Therefore, gene therapy for cancer has become a potential novel therapeutic modality. In this study we sought to determine the inhibitory effects of adenovirus-mediated human interleukin-24 (AdhIL-24) on pancreatic cancer.</p><p><b>METHODS</b>Human interleukin-24 gene was cloned into replication-defective adenovirus specific for patu8988 tumor cells by virus recombination technology. Reverse transcription-polymerase chain reaction and Western blotting analysis were used to determine the expression of human interleukin-24 mRNA in patu8988 cells in vitro. Induction of apoptosis by overexpression of human interleukin-24 in patu8988 cells was determined by flow cytometry. In vivo efficacy of adenoviral delivery of human interleukin-24 was assessed in nude mice (n = 10 for each group) bearing patu8988 pancreatic cancer cell lines by determining inhibition of tumor growth, endothelial growth factor and CD34 expression, and intratumoral microvessel density (MVD).</p><p><b>RESULTS</b>The recombinant adenovirus vector AdVGFP/IL-24 was constructed with a packaged recombinant retrovirus titer of 1.0 x 10(10) pfu/ml and successfully expressed of both mRNA and protein in patu8988 cells. The AdVGFP/IL-24 induced apoptosis of patu8988 tumor cells in vitro and significantly inhibited tumor growth in vivo (P < 0.05). The intratumoral MVD decreased significantly in the treated tumors (P < 0.05).</p><p><b>CONCLUSION</b>The recombinant adenovirus AdGFP/IL-24 can effectively express biologically active human interleukin-24, which results in inhibition of pancreatic cancer growth.</p>
Subject(s)
Animals , Humans , Male , Mice , Adenoviridae , Genetics , Antigens, CD34 , Blotting, Western , Flow Cytometry , Genetic Therapy , Genetic Vectors , Interleukins , Genetics , Mice, Inbred BALB C , Pancreatic Neoplasms , Pathology , Therapeutics , Transfection , Vascular Endothelial Growth Factor AABSTRACT
Glucoamylase overproducing A. niger T21 was mutated by UV mutagensis. An extracellular acid protease-deficient mutant, A. niger T21-201, which produced only 0.76% extracellular acid protease activity of the parent strain, was screened by casein-degradating plate and determination of protease activity. Moreover, the growth properties and the ability to secrete glucoamylase of A. niger T21-201 are identical to these of starting strain T21. The comparison of expression-secretion levels of heterologous gene in A. niger T21-201 and T21 was carried out with bacterial vhb as reporter, the level of expression-secretion of VHb in A. niger T21-201 was 6-7 times higher than that in T21, but the transcriptional levels of vhb gene in both strains were similar revealed by Northern blot. Therefore, it was demonstrated that the deficiency of acid protease of recipient T21-201 has significant effect on the protection of heterologous protein.