Abstract
217 Background: Activation of signal transducer and activator of transcription 5b (STAT5b) has been associated with tumor growth and metastases in various tumor entities. A number of cytokines, growth factors, and oncogenes that can induce STAT5b activity are also implicated in pancreatic cancer growth and metastases. Hence, we sought to determine STAT5b expression in human pancreatic cancer specimen and effects of selective STAT5b inhibition on pancreatic cancer cells. Methods: Expression of STAT5b in human pancreatic adenocarcinomas was determined by immunohistochemistry. For in vitro experiments, human pancreatic cancer cell lines (BxPC-3, HPAF-II, L3.6pl) were used. Cancer cells were transfected with STAT5b shRNA plasmid to create stable STAT5b knock-down. Effects of STAT5b inhibition on growth and motility of tumor cells was investigated by MTT and modified Boyden chamber assays. In vivo effects of STAT5b blockade were determined in subcutaneous mouse model. Results: Nuclear expression of STAT5b was detected in 42/80 human pancreatic adenocarcinomas. In human cancer cell lines, stable knock-down of STAT5b had no effect on growth of tumor cells in vitro. However, tumor cell motility was significantly reduced upon STAT5b blockade (p<0.05). Moreover, expression of various signaling intermediates and transcription factors including c-myc was impaired upon STAT5b knock-down. In a subcutaneous tumor model, inhibition of STAT5b led to significantly reduced tumor growth (p<0.05) which was also reflected by final tumor weights (p<0.05). Furthermore, as revealed by immunohistochemistry, blockade of STAT5b significantly reduced tumor vascularization in vivo (p<0.05). Conclusions: STAT5b is expressed in human pancreatic adenocarcinomas. Blockade of STAT5b impairs cancer cell motility in vitro, suggesting antimetastatic potential. Moreover, inhibition of STAT5b significantly reduces tumor growth and tumor vascularization in vivo. Hence, STAT5b might be an interesting target for antineoplastic therapy in human pancreatic cancer. No significant financial relationships to disclose.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.