探讨血清CD44V6和VEGF在大鼠结直肠癌肝转移（CLM）诊断中的意义。

健康雌性SD大鼠72只，体重320～360 g，20周龄，按不重复抽样法分为CLM组（54只）和对照组（18只）。CLM组中二甲基肼连续皮下注射诱导成功建立大鼠CLM动物模型。分别于第13、17、21周处死CLM组和对照组动物，记录肝转移瘤大小及数量。采用ELISA动态检测不同时期的CD44V6和VEGF的表达。HE染色观察大鼠结直肠肿瘤和肝转移肿瘤标本的病理类型。观察两组大鼠实验过程中的情况；比较两组大鼠病理学检查结果以及血清CD44V6、VEGF水平；观察CLM组大鼠血清CD44V6和VEGF阳性表达情况。两组实验数据比较采用t检验，三组比较采用单因素方差分析和LSD-t检验。

随着实验时间延长，CLM组肝转移瘤结节数逐渐增多，转移瘤结节直径逐渐增加（F=22.78，33.86；P<0.05）。对照组大鼠的结直肠和肝脏均未发现肿瘤和息肉。随着实验时间延长，CLM组血清CD44V6和VEGF水平逐渐升高（F=12.35，18.26；P<0.05）。CLM组13、17、21周血清CD44V6和17、21周血清VEGF水平分别为（15±5）、（19±6）、（36±4）μg/L和（106±6）、（195±22） ng/L，明显高于对照组的（10±3）、（11±4）、（12±3） μg/L和（76±18）、（75±18） ng/L（t=2.12，2.50，2.96和2.38，3.49；P<0.05）。随着实验时间延长，CLM组血清CD44V6、VEGF阳性率逐渐升高；两个指标联合检测时，其中任意一项为阳性的百分率高于任意单项的检测结果；实验21周时，两者阳性率达100%。

随着病情的进展，CLM大鼠血清CD44V6和VEGF水平逐渐升高。联合检测血清CD44V6和VEGF水平可能有助于早期诊断CLM。

To investigate the significance of serum CD44V6 and VEGF in the diagnosis of colorectal cancer liver metastasis (CLM) in rats.

Seventy-two healthy female SD rats with the weight of 320-360 g and the age of 20 weeks were divided into the CLM group (n=54) and control group (n=18) according to the nonreplacement sampling method. CLM rat models were successfully established by continuously subcutaneous injection of dimethyl hydrazine in the CLM group. The animals in two groups were respectively sacrificed at 13, 17 and 21 weeks. The size and quantity of metastatic liver tumors were recorded. The expression of serum CD44V6 and VEGF at different time points were dynamically detected by ELISA. The pathological types of colorectal tumors and metastatic liver tumors were observed by HE staining. The status of the rats throughout the experimental process was observed in two groups. Pathological findings and serum CD44V6 and VEGF levels were compared between two groups. The positive expression of serum CD44V6 and VEGF in the CLM group was observed. The experimental data between two groups were compared by t test, and were compared by one-way analysis of variance and LSD-t test between three groups.

As the experiment time went on, the quantity and diameter of metastatic liver tumors in the CLM group gradually increased (F=22.78, 33.86; P<0.05). No tumor or polyp was observed in the colon, rectum and liver in the control group. As the experiment time went on, the serum CD44V6 and VEGF levels were gradually up-regulated (F=12.35, 18.26; P<0.05). The serum CD44V6 levels at 13, 17 and 21 weeks and the serum VEGF levels at 17 and 21 weeks were respectively (15±5), (19±6), (36±4) μg/L and (106±6), (195±22) ng/L in the CLM group, significantly higher than (10±3), (11±4), (12±3) μg/L and (76±18), (75±18) ng/L in the control group (t=2.12, 2.50, 2.96 and 2.38, 3.49; P<0.05). As the experiment time went on, the positive rates of serum CD44V6 and VEGF in the CLM group were gradually enhanced. When two indexes were combined detected, the positive rate of either index was higher than that of any single index. At 21 weeks, the positive rates of two indexes reached 100%.

Along with the progression of the disease, the serum CD44V6 and VEGF levels of the rats in the CLM group are gradually up-regulated. Combined detection of serum CD44V6 and VEGF may probably contribute to early diagnosis of CLM.