[Expression of Six1 and Six4 in esophageal squamous cell carcinoma and their correlation with clinical prognosis].
OBJECTIVE
Six1 and Six4 are expressed in several tumors, and associated with tumor progress and poor prognosis. The aim of this study was to investigate the expression of Six1 and Six4 in esophageal squamous cell carcinoma (ESCC), and to evaluate their correlation with the clinicopathological factors and prognosis.


METHODS
Tissue microarray technology and immunohistochemical method (EnVision) were used to detect the expression of Six1 and Six4 in the tumor tissues and corresponding adjacent normal epithelium of esophagus from 292 ESCC patients.


RESULTS
Among the 292 ESCC patients, the positive rates of Six1 and Six4 protein expression in tumor tissues were 72.9% (213/292) and 56.2% (164/292), respectively, significantly higher than the expression rate of 33.2% (97/292) and 32.5% (95/292) in adjacent normal epithelium of esophagus (P < 0.05). Chi square test showed that the expression of Six1 protein was related to tumor size, depth of tumor invasion and patient survival status; higher Six4 protein expression level was related to poor differentiation and increased depth of invasion. Single factor Log-rank analysis revealed that gender, TNM stage, Six1 protein expression level were related to the overall survival of ESCC patients (P < 0.05), while the five-year survival rate was significantly higher in the Six1-negative group than the Six1-positive group [51.9% (41/79) vs. 43.7% (93/213)]. Multi-factor Cox proportional risk model analysis showed that TNM stage and positive expression of Six1 were independent prognostic factors for ESCC patients (P < 0.05).


CONCLUSIONS
Six1 and Six4 are highly expressed in ESCC. Their expression levels are closely related to the progress and prognosis of ESCC. Over-expression of Six1 is related to poor prognosis in ESCC patients. Thus, Six1 could be used as an important prognostic indicator for ESCC patients.
Department of Pathology, Shanghai Medical College, Fudan University, Shanghai 200032, China.
Qiao
Q
Wei
Wei-wei
WW
Yu
Kuai-le
KL
Zhao
Xiao-long
XL
Fu
Zheng-fei
ZF
Zhu
Guang-qi
GQ
Qin
Huan
H
Chen
Zhuan-xu
ZX
Zhang
Yan-zi
YZ
Gu
Jia-qing
JQ
Xiang
Hai-quan
HQ
Chen
Xiang
X
Du
Meng-hong
MH
Sun
D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000378:metabolism* / Q000473:pathology* / Q000601:surgery; D004938:Esophageal Neoplasms / Q000378:metabolism* / Q000473:pathology* / Q000601:surgery; D000077277:Esophageal Squamous Cell Carcinoma; D005260:Female; D005500:Follow-Up Studies; D018398:Homeodomain Proteins / Q000378:metabolism*; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D011379:Prognosis; D016016:Proportional Hazards Models; D012307:Risk Factors; D015996:Survival Rate; D015534:Trans-Activators / Q000378:metabolism*; D047368:Tumor Burden
D018398:Homeodomain Proteins; C099236:SIX1 protein, human; C490851:SIX4 protein, human; D015534:Trans-Activators