James J Lee

Publications of James J Lee

• Hypoxia activates the cyclooxygenase-2-prostaglandin E synthase axis.

  Authors: James J Lee, Mitsuteru Natsuizaka, Shinya Ohashi, Gabrielle S Wong, Munenori Takaoka, Carmen Z Michaylira, Daniela Budo, John W Tobias, Michiyuki Kanai, Yasuhiro Shirakawa, Yoshio Naomoto, Andres J P Klein-Szanto, Volker H Haase, Hiroshi Nakagawa

  Carcinogenesis. 03/2010; 31(3):427-34.

  Hypoxia-inducible factors (HIFs), in particular HIF-1alpha, have been implicated in tumor biology. However, HIF target genes in the esophageal tumor microenvironment remain elusive. Gene expressionHypoxia-inducible factors (HIFs), in particular HIF-1alpha, have been implicated in tumor biology. However, HIF target genes in the esophageal tumor microenvironment remain elusive. Gene expression profiling was performed upon hypoxia-exposed non-transformed immortalized human esophageal epithelial cells, EPC2-hTERT, and comparing with a gene signature of esophageal squamous cell carcinoma (ESCC). In addition to known HIF-1alpha target genes such as carbonic anhydrase 9, insulin-like growth factor binding protein-3 (IGFBP3) and cyclooxygenase (COX)-2, prostaglandin E synthase (PTGES) was identified as a novel target gene among the commonly upregulated genes in ESCC as well as the cells exposed to hypoxia. The PTGES induction was augmented upon stabilization of HIF-1alpha by hypoxia or cobalt chloride under normoxic conditions and suppressed by dominant-negative HIF-1alpha. Whereas PTGES messenger RNA (mRNA) was negatively regulated by normoxia, PTGES protein remained stable upon reoxygenation. Prostaglandin E(2) (PGE(2)) biosynthesis was documented in transformed human esophageal cells by ectopic expression of PTGES as well as RNA interference directed against PTGES. Moreover, hypoxia stimulated PGE(2) production in a HIF-1alpha-dependent manner. In ESCC, PTGES was overexpressed frequently at the mRNA and protein levels. Finally, COX-2 and PTGES were colocalized in primary tumors along with HIF-1alpha and IGFBP3. Activation of the COX-2-PTGES axis in primary tumors was further corroborated by concomitant upregulation of interleukin-1beta and downregulation of hydroxylprostaglandin dehydrogenase. Thus, PTGES is a novel HIF-1alpha target gene, involved in prostaglandin E biosynthesis in the esophageal tumor hypoxic microenvironment, and this has implications in diverse tumors types, especially of squamous origin.

• From Virtual Organization to E-Business: Transformational Structuration.

  Authors: James J. Lee, Bandula Jayatilaka, Ben B. Kim, Ted E. Lee, Pairin Katerattanakul, Soongoo Hong

  IJEBR. 01/2010; 6:13-25.

• Effect of Business Characteristics and ERP Implementation Strategies on ERP Outcomes: An Exploratory Study.

  Authors: Pairin Katerattanakul, James J. Lee, Soongoo Hong, Hwee-Joo Kam

  Proceedings of the 15th Americas Conference on Information Systems, AMCIS 2009, San Francisco, California, USA, August 6-9, 2009; 01/2009

• Migrating Legacy Systems in the Global Merger & Acquisition Environment Teaching Case.

  Authors: Pairin Katerattanakul, Hwee-Joo Kam, James J. Lee, Soongoo Hong

  Learning from the past & charting the future of the discipline. 14th Americas Conference on Information Systems, AMCIS 2008, Toronto, Ontario, Canada, August 14-17, 2008; 01/2008

• IGFBP-3 regulates esophageal tumor growth through IGF-dependent and independent mechanisms.

  Authors: Munenori Takaoka, Seok Hyun Kim, Takaomi Okawa, Carmen Z Michaylira, Douglas B Stairs, Cameron N Johnstone, Claudia D Andl, Ben Rhoades, James J Lee, Andres J P Klein-Szanto, Wafik S El-Deiry, Hiroshi Nakagawa

  Cancer biology & therapy. 05/2007; 6(4):534-40.

  Insulin-like growth factor binding protein (IGFBP)-3 exerts either proapoptotic or growth stimulatory effects depending upon the cellular context. IGFBP-3 is overexpressed frequently in esophagealInsulin-like growth factor binding protein (IGFBP)-3 exerts either proapoptotic or growth stimulatory effects depending upon the cellular context. IGFBP-3 is overexpressed frequently in esophageal cancer. Yet, the role of IGFBP-3 in esophageal tumor biology remains elusive. To delineate the functional consequences of IGFBP-3 overexpression, we stably transduced Ha-Ras(V12)-transformed human esophageal cells with either wild-type or mutant IGFBP-3, the latter incapable of binding Insulin-like growth factor (IGFs) as a result of substitution of amino-terminal Ile56, Leu80, and Leu81 residues with Glycine residues. Wild-type, but not mutant, IGFBP-3 prevented IGF-1 from activating the IGF-1 receptor and AKT, and suppressed anchorage-independent cell growth. When xenografted in nude mice, in vivo bioluminescence imaging demonstrated that wild-type, but not mutant IGFBP-3, abrogated tumor formation by the Ras-transformed cells with concurrent induction of apoptosis, implying a prosurvival effect of IGF in cancer cell adaptation to the microenvironment. Moreover, there was more aggressive tumor growth by mutant IGFBP-3 overexpressing cells than control cell tumors, without detectable caspase-3 cleavage in tumor tissues, indicating an IGF-independent growth stimulatory effect of mutant IGFBP-3. In aggregate, these data suggest that IGFBP-3 contributes to esophageal tumor development and progression through IGF-dependent and independent mechanisms.