Significance of karyopherin-{alpha} 2 (KPNA2) expression in esophageal squamous cell carcinoma.
BACKGROUND
Karyopherin-alpha 2 (KPNA2) is a member of the importin alpha family and has recently been reported to play an important role in tumorigenesis and tumor progression. The aim of the current study was to elucidate the clinicopathological significance of immunohistochemical expression of KPNA2 in esophageal squamous cell carcinoma (ESCC).


METHODS
KPNA2 expression was investigated by immunohistochemistry in 116 surgically resected ESCC, and the association of KPNA2 expression with clinicopathologic features was also examined.


RESULTS
Sixty (51.7%) ESCCs demonstrated positive expression of KPNA2. Positive expression of KPNA2 showed a significant association with poor differentiation (p=0.015), tumor depth (p=0.001), lymphatic invasion (p<0.001), venous invasion (p<0.001), and tumor stage (p=0.008). Positive expression of KPNA2 was also significantly associated with Ki-67 labeling index (p=0.039). Univariate analysis revealed that the prognosis of the ESCC patients whose tumors demonstrated positive expression of KPNA2 was significantly poorer than that of those that did not (p=0.009). Multivariate analysis revealed that only tumor depth and the presence of lymph node metastasis, which are strong prognostic factors in ESCC, were independently associated with poor prognosis in this study.


CONCLUSIONS
KPNA2 expression is associated with poor differentiation, tumor invasiveness, and tumor proliferation in ESCC.
Sakai
Makoto
M
Department of General Surgical Science, Gunma University, Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan. maksakai@med.gunma-u.ac.jp
Sohda
Makoto
M
Miyazaki
Tatsuya
T
Suzuki
Shigemasa
S
Sano
Akihiko
A
Tanaka
Naritaka
N
Inose
Takanori
T
Nakajima
Masanobu
M
Kato
Hiroyuki
H
Kuwano
Hiroyuki
H
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000378:metabolism* / Q000473:pathology; D002454:Cell Differentiation / Q000502:physiology; D048708:Cell Growth Processes / Q000502:physiology; D004938:Esophageal Neoplasms / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D028901:alpha Karyopherins / Q000096:biosynthesis*
C490630:KPNA2 protein, human; D028901:alpha Karyopherins