Expression of the human phosphatases of regenerating liver (PRLs) in colonic adenocarcinoma and its correlation with lymph node metastasis.
BACKGROUND
Human phosphatases of regenerating liver (PRLs) can induce cell growth, differentiation, and malignant transformation. In this study, we used specific polyclonal antibodies against PRLs to investigate their expression in colonic adenocarcinomas and its correlation with patient gender, age, tumor differentiation, localization, invasion, and metastasis.


METHODS
The polyclonal antibodies against PRL-1, PRL-2, and PRL-3 were produced and purified. The expression of PRLs in human colorectal carcinoma cell lines (SW480 and SW620) was examined by Western blotting. We also examined their expression in normal and pathologic tissues from the human colon. The tissues included 49 primary colonic adenocarcinomas, 14 cases with lymph node metastases, 15 colonic adenomas, and 12 normal colon samples. Hematoxylin and eosin staining, immunohistochemistry, and semiquantitative morphological analysis were used to evaluate the sections.


RESULTS
PRLs were widely expressed in SW480 and SW620. PRL-1, PRL-2, and PRL-3 were expressed, respectively, in 16, 10, and 16% of primary colonic adenocarcinomas. In contrast, PRLs were strongly expressed in all lymph node metastases. There were no significant correlations between the expression of PRLs and patient gender, age, tumor differentiation, depth of invasion, or localization of tumor within the different sections of the colon. PRLs were not expressed in normal colon tissues or in colonic adenomas. PRLs were mainly expressed in the cytoplasm and at the cytoplasmic membranes of the colonic adenocarcinoma cells as well as in the endothelial cells and the surrounding smooth muscle cells of larger vessels in the lymph node metastases.


CONCLUSIONS
Colonic adenocarcinoma cells have the ability to produce PRLs, which may relate to the lymph node metastasis of colonic adenocarcinoma.
Wang
Ying
Y
The Key Laboratory of Pathobiology, Ministry of Education, Jilin University, Changchun, China. happywy123@yahoo.com.cn
Li
Zhao-Fa
ZF
He
Jin
J
Li
Yi-Lei
YL
Zhu
Gui-Bin
GB
Zhang
Li-Hong
LH
Li
Yu-Lin
YL
D000230:Adenocarcinoma / Q000201:enzymology* / Q000473:pathology; D018797:Cell Cycle Proteins / Q000378:metabolism*; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000201:enzymology* / Q000473:pathology; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis / Q000473:pathology*; D008565:Membrane Proteins / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000378:metabolism*; D017027:Protein Tyrosine Phosphatases / Q000378:metabolism*
D018797:Cell Cycle Proteins; D008565:Membrane Proteins; D009363:Neoplasm Proteins; C490198:PTP4A1 protein, human; C487561:PTP4A2 protein, human; C484730:PTP4A3 protein, human; D017027:Protein Tyrosine Phosphatases