Wu Qiu-Wan, Yang Qing-Mo, Huang Yu-Fan, She Hong-Qiang, Liang Jing, Yang Qiao-Lu, Zhang Zhi-Ming
Xiamen Cancer Center and Department of Breast Surgery, The First Affiliated Hospital of Xiamen University, Xiamen, China.
PLoS One. 2014 May 20;9(5):e97804. doi: 10.1371/journal.pone.0097804. eCollection 2014.
Matrix metalloproteinase 9 (MMP-9) is a type-IV collagenase that is highly expressed in breast cancer, but its exact role in tumor progression and metastasis is unclear.
MMP-9 mRNA and protein expression was examined by real-time reverse transcriptase PCR and immunohistochemical staining, respectively, in 41 breast cancer specimens with matched peritumoral benign breast epithelial tissue and suspicious metastatic axillary lymph nodes. Lymph vessels were labeled with D2-40 and lymphatic microvessel density (LMVD) was calculated. Correlation of MMP-9 protein expression with clinicopathological parameters and LMVD was also evaluated.
MMP-9(+) staining in breast cancer specimens (35/41, 85.4%) was higher than in matched epithelium (21/41, 51.2%; P<0.05) and lymph nodes (13/41, 31.7%; P<0.001). Higher MMP-9 mRNA expression was also detected in tumor specimens compared with matched epithelial tissues and lymph nodes (P<0.05). Elevated MMP-9 expression was correlated with lymph node metastasis and LMVD (P<0.05).
MMP-9 was overexpressed in breast cancer specimens compared with peritumoral benign breast epithelium and lymph nodes. Moreover, its expression in the matched epithelium and lymph nodes was positively associated with lymph node metastasis, and its expression in lymph nodes was positively associated with lymphangiogenesis in breast cancer. Thus, MMP-9 is a potential marker for breast cancer progression.
基质金属蛋白酶9（MMP-9）是一种IV型胶原酶，在乳腺癌中高表达，但其在肿瘤进展和转移中的确切作用尚不清楚。
分别采用实时逆转录聚合酶链反应和免疫组织化学染色检测41例乳腺癌标本及其配对的瘤旁乳腺良性上皮组织和可疑转移腋窝淋巴结中MMP-9 mRNA和蛋白的表达。用D2-40标记淋巴管并计算淋巴管微血管密度（LMVD）。还评估了MMP-9蛋白表达与临床病理参数及LMVD的相关性。
乳腺癌标本中MMP-9（+）染色（35/41，85.4%）高于配对的上皮组织（21/41，51.2%；P<0.05）和淋巴结（13/41，31.7%；P<0.001）。与配对的上皮组织和淋巴结相比，肿瘤标本中也检测到较高的MMP-9 mRNA表达（P<0.05）。MMP-9表达升高与淋巴结转移和LMVD相关（P<0.05）。
与瘤旁乳腺良性上皮组织和淋巴结相比，MMP-9在乳腺癌标本中过表达。此外，其在配对上皮组织和淋巴结中的表达与淋巴结转移呈正相关，其在淋巴结中的表达与乳腺癌淋巴管生成呈正相关。因此，MMP-9是乳腺癌进展的潜在标志物。
