High expression level and nuclear localization of Sam68 are associated with progression and poor prognosis in colorectal cancer.
Src-associated in mitosis (Sam68; 68 kDa) has been implicated in the oncogenesis and progression of several human cancers. The aim of this study was to investigate the clinicopathologic significance of Sam68 expression and its subcellular localization in colorectal cancer (CRC).



Sam68 expression was examined in CRC cell lines, nine matched CRC tissues and adjacent noncancerous tissues using reverse transcription (RT)-PCR, quantitative RT-PCR and Western blotting. Sam68 protein expression and localization were determined in 224 paraffin-embedded archived CRC samples using immunohistochemistry. Statistical analyses were applied to evaluate the clinicopathologic significance.



Sam68 was upregulated in CRC cell lines and CRC, as compared with normal tissues; high Sam68 expression was detected in 120/224 (53.6%) of the CRC tissues. High Sam68 expression correlated significantly with poor differentiation (P = 0.033), advanced T stage (P < 0.001), N stage (P = 0.023) and distant metastasis (P = 0.033). Sam68 nuclear localization correlated significantly with poor differentiation (P = 0.002) and T stage (P =0.021). Patients with high Sam68 expression or Sam68 nuclear localization had poorer overall survival than patients with low Sam68 expression or Sam68 cytoplasmic localization. Patients with high Sam68 expression had a higher risk of recurrence than those with low Sam68 expression.



Overexpression of Sam68 correlated highly with cancer progression and poor differentiation in CRC. High Sam68 expression and Sam68 nuclear localization were associated with poorer overall survival.
Wen-Ting
WT
Liao
Jun-Ling
JL
Liu
Zheng-Gen
ZG
Wang
Yan-Mei
YM
Cui
Ling
L
Shi
Ting-Ting
TT
Li
Xiao-Hui
XH
Zhao
Xiu-Ting
XT
Chen
Yan-Qing
YQ
Ding
Li-Bing
LB
Song
D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism*; D045744:Cell Line, Tumor; D015179:Colorectal Neoplasms / Q000378:metabolism* / Q000473:pathology*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D018450:Disease Progression; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012333:RNA, Messenger / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism*; D016019:Survival Analysis; D015854:Up-Regulation; D055815:Young Adult
D048868:Adaptor Proteins, Signal Transducing; D014408:Biomarkers, Tumor; D004268:DNA-Binding Proteins; C489559:KHDRBS1 protein, human; D012333:RNA, Messenger; D016601:RNA-Binding Proteins