LRP16基因在乳腺癌组织中的表达及其临床意义

Expression and Clinical Significance of LRP16 Gene in Human Breast Cancer

背景与目的:既往研究表明雌激素通过其受体!直接上调LRP16的表达,LRP16基因的高表达促进乳腺癌细胞的增殖。本研究旨在探讨LRP16基因在乳腺癌组织中的表达状况及其与临床病理特征的关系。方法:收集52例乳腺癌组织及其配对癌旁组织,Northernblot与半定量RT-PCR法分别检测22例和30例标本中LRP16mRNA水平。免疫组化法检测肿瘤组织中雌激素受体(ER)、孕激素受体(PR)及Ki-67的表达情况。结果:Northernblot检测结果表明,22例癌组织LRP16mRNA的表达较癌旁组织高2倍的有9例,高表达率为40.9%(9/22)。高表达LRP16的9例中有7例ER阳性,8例PR阳性;而非高表达13例中ER阳性6例,PR阳性5例,两组ER与PR阳性率均有显著性差异(P<0.05)。LRP16高表达的9例中只有1例PR和ER同时阴性,而非高表达的13例中有7例。22例患者中,13例肿瘤直径3.0～4.5cm,其中LRP16基因高表达组占8例;有腋窝淋巴结转移的12例中8例LRP16高表达。8例高表达Ki-67患者中6例LRP16高表达。半定量RT-PCR检测结果表明,30例肿瘤标本中9例(30.0%)LRP16mRNA的表达水平明显高于癌旁组织,9例LRP16高表达者ER、PR均阳性,Ki-67高表达,且瘤体直径均大于3.5cm,均有腋窝淋巴结转移,与非高表达组比较差异有显著性(P<0.05)。结论:LRP16基因表达水平与ER/PR阳性率、细胞增殖活性、肿瘤直径、远处淋巴结转移密切相关,提示LRP16基因可能参与促进乳腺癌的增殖与转移。

BACKGROUND ＆ OBJECTIVE： Estrogen directly up-regulates LRP16 gene expression via activating its receptor （ER）, and the overexpression of LRP16 promotes the proliferation of human breast cancer cells. This study was to detect the mRNA level of LRP16 gene in breast cancer, and investigate its correlation to the clinicopathologic features. METHODS： The mRNA level of LRP16 in carcinoma and matched peritumor tissues from 22 breast cancer patients was detected by Northern blot, and that in the tissues from 30 patients was detected by semi-quantitative reverse transcription-polymerase chain reaction （RT-PCR）. The expression of Ki-67, ER, and progesterone receptor （PR） in the carcinoma tissues was detected by immunohistochemistry. RESULTS： According to the results of Northern blot, compared with that in peritumor tissues, LRP16 was overexpressed by 2 folds in 9 （40.9%） out of 22 breast cancer samples. Of the 9 samples with LRP16 overexpression, 7 were ER-positive, and 8 were PR-positive; of the 13 samples without LRP16 overexpression, 6 were ER-positive, and 5 were PR-negative. The positive rates of ER and PR were significantly higher in the samples with LRP16 overexpression than in the samples without LRP16 overexpression （P〈0.05）. Only 1 of the 9 samples with LRP16 overexpression was negative for both ER and PR, but 7 of the 13 without LRP16 overexpression were negative for both of them. The proportion of the tumors with diameters of 3.0-4.5 cm was significantly higher in the patients with LRP16 overexpression than in those without LRP16 overexpression （8/9 vs. 5/13, P=0.031）. Axiltary lymph node metastasis was detected in 12 out of 22 patients, including 8 of the 9 patients with LRP16 overexpression and 4 of the 13 without LRP16 overexpression （P=0.011）. In addition, LRP16 overexpression was detected in 6 of the 8 patients with Ki-67 overexpression, and 2 of the 14 patients without Ki-67 overexpression （P=0.026）. According to the results of RT-PCR, LRP16 was overexpressed in 9 （30%） out of 30 breast cancer samples. All of the 9 samples with LRP16 overexpression were positive for both ER and PR, with Ki-67 overexpression, tumor diameters of more than 3.5 cm and axillary lymph node metastasis. The differences between the patients with or without LRP16 overexpression were significant （P〈0.05）. CONCLUSION： LRP16 overexpression is closely correlated to the positive rates of ER and PR, Ki-67 level, tumor diameter, and axillary lymph node metastasis of breast cancer, and might be involved in the proliferation and metastasis of human breast cancer.