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Pancreatic carcinoma is one of the most aggressive tumors, and, being refractory to conventional therapies, is an excellent target for new therapeutic approaches. Based on our previous finding of high HMGA1 expression in pancreatic cancer cells compared to normal pancreatic tissue, we evaluated whether suppression of HMGA1 protein expression could be a treatment option for patients affected by pancreatic cancer. Here we report that HMGA1 proteins are overexpressed in pancreatic carcinoma cell lines, and their downregulation through an adenovirus carrying the HMGA1 gene in an antisense orientation (Ad Yas-GFP) results in the death of three human pancreatic carcinoma cell lines (PANC1, Hs766T and PSN1). Pretreatment of PANC1 and PSN1 cells with Ad Yas-GFP suppressed and reduced, respectively, their ability to form xenograft tumors in nude mice. To further verify the role of HMGA1 in pancreatic tumorigenesis, we used a HMGA1 antisense phosphorothioate oligodeoxynucleotide (ODN); its addition induced a decrease in HMGA1 protein levels and a significant reduction of the proliferation rate of PANC1-, Hs766T- and PSN1-treated cells. Therefore, suppression of HMGA1 protein synthesis by an HMGA1 antisense approach seems to be a feasible treatment strategy in pancreatic carcinomas.Cancer Gene Therapy (2004) 11, 633-641. doi:10.1038/sj.cgt.7700745 Published online 23 July 2004 [ABSTRACT FROM AUTHOR]

Osteosarcoma (OS) is among the most frequently occurring primary bone tumors, primarily affecting adolescents and young adults. This malignant osteoid forming tumor is characterized by its metastatic potential, mainly to lungs. We recently demonstrated that WW domain-containing oxidoreductase (WWOX) is frequently inactivated in human OS and that WWOX restoration in WWOX-negative OS cells suppresses tumorigenicity. Of note, WWOX levels are reduced in paired OS samples of post-treatment metastastectomies as compared to pre-treatment biopsies suggesting that decreased WWOX levels are associated with a more aggressive phenotype at the metastatic site. Nevertheless, little is known about WWOX function in OS metastasis. Here, we investigated the role of tumor suppressor WWOX in suppressing pulmonary OS metastasis both in vitro and in vivo. We demonstrated that ectopic expression of WWOX in OS cells, HOS and LM-7, inhibits OS invasion and cell migration in vitro. Furthermore, WWOX expression reduced tumor burden in vivo and inhibited metastases' seeding and colonization. Mechanistically, WWOX function is associated with reduced levels of RUNX2 metastatic target genes implicated in adhesion and motility. Our results suggest that WWOX plays a critical role in determining the aggressive phenotype of OS, and its expression could be an attractive therapeutic target to combat this devastating adolescent disease. [ABSTRACT FROM AUTHOR]