Collapsin response mediator protein-1 and the invasion and metastasis of cancer cells.
BACKGROUND
Numerous genetic changes are associated with metastasis and invasion of cancer cells. To identify differentially expressed invasion-associated genes, we screened a panel of lung cancer cell lines (CL(1-0), CL(1-1), CL(1-5), and CL(1-5)-F(4) in order of increasing invasive activity) for such genes and selected one gene, collapsin response mediator protein-1 (CRMP-1), to characterize.


METHODS
We used a microarray containing 9600 gene sequences to assess gene expression in the cell panel and selected the differentially expressed CRMP-1 gene for further study. We confirmed the differential expression of CRMP-1 with northern and western blot analyses. After transfecting and overexpressing CRMP-1 in highly invasive CL(1-5) cells, the cells were assessed morphologically and with an in vitro invasion assay. We used enhanced green fluorescent protein-tagged CRMP-1 and fluorescence microscopy to localize CRMP-1 intracellularly. CRMP-1 expression in 80 lung cancer specimens was determined by real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR). All statistical tests were two-sided.


RESULTS
Expression of CRMP-1 was inversely associated with invasive activity in the cell panel, an observation confirmed by northern and western blot analyses. CRMP-1-transfected CL(1-5) cells became rounded and had fewer filopodia and statistically significantly lower in vitro invasive activity than untransfected cells (all P< .001). During interphase, CRMP-1 protein was present uniformly throughout the cytoplasm and sometimes in the nucleus; during mitosis, CRMP-1 was associated with mitotic spindles, centrosomes, and the midbody (in late telophase). Real-time RT-PCR of lung cancer specimens showed that reduced expression of CRMP-1 was statistically significantly associated with advanced disease (stage III or IV; P = .010), lymph node metastasis (N1, N2, and N3; P =.043), early postoperative relapse (P = .030), and shorter survival (P = .016).


CONCLUSIONS
CRMP-1 appears to be involved in cancer invasion and metastasis and may be an invasion-suppressor gene.
Shih
J Y
JY
Department of Internal Medicine, National Taiwan University Hospital, Taipei.
Yang
S C
SC
Hong
T M
TM
Yuan
A
A
Chen
J J
JJ
Yu
C J
CJ
Chang
Y L
YL
Lee
Y C
YC
Peck
K
K
Wu
C W
CW
Yang
P C
PC
D000199:Actins / Q000737:chemistry; D000230:Adenocarcinoma / Q000235:genetics / Q000401:mortality / Q000473:pathology*; D000368:Aged; D015152:Blotting, Northern; D015153:Blotting, Western; D018288:Carcinoma, Small Cell / Q000235:genetics / Q000401:mortality / Q000473:pathology*; D002453:Cell Cycle / Q000235:genetics; D018572:Disease-Free Survival; D005260:Female; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D015993:Life Tables; D008175:Lung Neoplasms / Q000235:genetics / Q000401:mortality / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness / Q000235:genetics*; D009362:Neoplasm Metastasis / Q000235:genetics*; D009363:Neoplasm Proteins / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D009419:Nerve Tissue Proteins / Q000032:analysis / Q000096:biosynthesis / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D020411:Oligonucleotide Array Sequence Analysis; D010750:Phosphoproteins / Q000032:analysis / Q000096:biosynthesis / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D012333:RNA, Messenger / Q000032:analysis; D012334:RNA, Neoplasm / Q000032:analysis; D011993:Recombinant Fusion Proteins / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D008941:Spindle Apparatus / Q000737:chemistry; D013347:Subcellular Fractions / Q000737:chemistry; D016019:Survival Analysis; D014162:Transfection; D014407:Tumor Cells, Cultured; D000098855:Collapsin Response Mediator Protein 1
D000199:Actins; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D010750:Phosphoproteins; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D011993:Recombinant Fusion Proteins; D000098855:Collapsin Response Mediator Protein 1