Oncogenic effect of Polo-like kinase 1 expression in human gastric carcinomas.
Polo-like kinase 1 (Plk1) is one of the serine/threonine kinases involved in various mitotic processes, such as centrosome maturation and chromosome segregation. Although Plk1 is increased in several tumor types, the effect of Plk1 in gastric cancer is not clear because of the limited patient numbers in previous studies. This study was performed to investigate the prognostic significance and the expression profiles of Plk1 in gastric carcinoma tissues from 280 Korean patients. The expression of Plk1 was analyzed by reverse transcriptional PCR and a tissue array using immunohistochemical staining method in gastric adenocarcinoma tissues. The oncogenic potential of Plk1 was analyzed by using Plk1-specific small interference RNA in gastric cancer cells. The message of Plk1 was increased in various gastric cancer cell types and in primary cancer specimens in comparison with normal tissue. The expression rate of Plk1 was 95% (268/280) in gastric carcinoma patients. Although Plk1 expression had no specific correlation in male or female patients, among the differentiation types of cancer, its expression was generally increased in gastric cancers. Plk1 expression was significantly associated with accumulation of proliferation-related genes and oncogenes, and reversely correlated with tumor suppressor genes. When Plk1 expression was blocked, cancer cell growth was inhibited and apoptotic phenotypes were detected. Overexpression of Plk1 was important in abnormal proliferation and showed oncogenic potential in gastric cancer. Plk1 might have potential as a tumor prognostic marker for gastric cancer.
Jang
Young-Joo
YJ
Laboratory of Biochemistry, The School of Dentistry, Dankook University, Cheonan-Si, Chungnam 330-714, Korea. yjjang@dku.edu
Kim
Yong Sung
YS
Kim
Woo Ho
WH
D000230:Adenocarcinoma / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D014408:Biomarkers, Tumor / Q000235:genetics*; D018797:Cell Cycle Proteins / Q000235:genetics*; D002454:Cell Differentiation; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002471:Cell Transformation, Neoplastic; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology*; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D009857:Oncogenes / Q000502:physiology*; D011379:Prognosis; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D000097869:Polo-Like Kinase 1
D014408:Biomarkers, Tumor; D018797:Cell Cycle Proteins; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D000097869:Polo-Like Kinase 1