Overexpression　of　the　neutrophil　gelatinase-associated　lipocalin　(NGAL)　gene　is　related　to　malignant　transformation　of　human　immortalized　esophageal　epithelial　cell　induced　by　12-O-tetradecanoyl　phorbol　13-acetate　(TPA).　However,　the　mechanisms　of　the　transcriptional　activation　of　this　gene　remain　unclear.　The　recent　study　indicated　that　there　might　be　TPA　response　elements　in　the　5′　flanking　promoter　region　and　the　sequences　surrounding　it.　In　order　to　locate　the　position　of　TPA　response　elements,　the　NGAL　fragments　for　-152∼+84,　-140∼+84,　-78∼+84,　-59∼+84,　-50∼+84,　-41∼+84,　-37∼+84,　-29∼+84　and　-10∼+84　were　obtained　from　esophageal　cancer　cells　by　PCR　and　nested　deletion　and　cloned　into　pGL3-Basic　(pGLB),　pGL3-Enhancer　(pGLE)　and　pGL3-promoter　(pGLP)　vector　which　are　luciferase　reporters,　respectively.　The　constructed　recombinant　expression　plasmids　pGLB-152,　pGLP-152,　pGLE-152,　pGLB-140,　pGLB-78,　pGLB-59,　pGLB-50,　pGLB-41,　pGLB-37,　pGLB-29　and　pGLB-10　were　adopted　to　cotransfect　with　pRL-TK　into　EC109　esophageal　cancer　cells　stimulated　with　TPA　(5　μg/L)　respectively　or　not.　Relative　luciferase　activity　of　whole　cell　extracts　from　cells　was　measured　with　Dual　Luciferase　Report　Gene　Assay　System　(DLR)　to　verify　the　position　of　TPA　response　elements.　Results　showed　that　the　TPA　response　elements　of　NGAL　are　located　on　-152∼-60　region　and　have　a　strong　response　to　TPA　stimulation　in　the　esophageal　cancer　cells.　The　analysis　by　bioinformatics　showed　that　the　potential　TPA　responsive　element　in　-152∼-60　position　of　NGAL　is　a　new　sequence.　This　suggested　that　there　is　the　structural　character　responding　to　TPA　induction　in　the　gene.　These　results　will　help　to　clarify　the　molecular　mechanisms　of　NGAL　overexpression　in　malignant　transformation　of　human　immortalized　esophageal　epithelial　cell　induced　by　TPA.