title: An essential role of PDCD4 in progression and malignant proliferation of gastrointestinal stromal tumors.
abstract: Programmed cell death 4 (PDCD4) is a tumor suppressor that can inhibit tumorigenesis by suppressing activator protein (AP)-1 activation and protein translation. Lost or decreased PDCD4 expression has been found in multiple types of human cancers, which was also associated with progression and metastasis of the tumors. However, the status and significance of PDCD4 in gastrointestinal stromal tumors have not been evaluated. In the present study, we examined the PDCD4 expression in a total of 63 gastrointestinal stromal tumor samples at both mRNA and protein levels by RT-PCR, western blot, and immunohistochemistry. We demonstrated that the expression of PDCD4 mRNA was diminished in 68% (17/25) of the tumor samples, and the level of PDCD4 protein appeared to be decreased in 66.7% (42/63) of the samples, as compared to adjacent normal gastrointestinal tissues, which expressed high levels of PDCD4 mRNA and protein. In addition, altered expression of PDCD4 was associated with clinicopathological parameters including risk group, tumor size, and mitosis. Moreover, PDCD4 expression had a negative correlation with the Ki-67 labeling index (r = -0.6059, P < 0.0001). All these results suggest that downregulation of PDCD4 expression may have an essential role in the progression and malignant proliferation of human gastrointestinal stromal tumors.
authors.affiliation: Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health, Shandong University Qilu Hospital, Jinan 250012, Shandong, China.
authors.forename: Lingling
authors.initials: L
authors.lastname: Ding
authors.forename: Xia
authors.initials: X
authors.lastname: Zhang
authors.forename: Miaoqing
authors.initials: M
authors.lastname: Zhao
authors.forename: Zhonghua
authors.initials: Z
authors.lastname: Qu
authors.forename: Shanying
authors.initials: S
authors.lastname: Huang
authors.forename: Mei
authors.initials: M
authors.lastname: Dong
authors.forename: Fei
authors.initials: F
authors.lastname: Gao
mesh_terms: D051017:Apoptosis Regulatory Proteins / Q000032:analysis / Q000096:biosynthesis*; D014408:Biomarkers, Tumor / Q000032:analysis*; D015153:Blotting, Western; D018450:Disease Progression; D015536:Down-Regulation; D005260:Female; D046152:Gastrointestinal Stromal Tumors / Q000378:metabolism* / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D016601:RNA-Binding Proteins / Q000032:analysis / Q000096:biosynthesis*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D051017:Apoptosis Regulatory Proteins; D014408:Biomarkers, Tumor; C114487:PDCD4 protein, human; D016601:RNA-Binding Proteins