The detection of micrometastases in the peripheral blood of patients with breast cancer for hSBEM mRNA and CD44V6 mRNA

Objective： Successful treatment of breast cancer greatly depends on the early detection of its metastasis, therefore a sensitive and specific biomarker for detecting dissemination of the cancer cells will help to achieve this goal. This study was to evaluate the prognostic significance of human small breast epithelial mucin （hSBEM） and CD44V6 in breast cancer. Methods： The expressions of hSBEM mRNA and CD44V6 mRNA were detected with nested reverse transcription polymerase chain reaction （nested RT-PCR） in 67 samples of breast cancer and adjacent normal breast tissue, 16 samples of breast benign lesions tissue, and 67 specimens of peripheral blood from patients with breast cancer, 16 specimens of benign breast lesions, 20 specimens of healthy volunteers, and 25 （each five cases） other carcinomas tissue samples, including those of gastric carcinoma, colorectal carcinoma, esophageal carcinoma, lung carcinoma, and ovary carcinoma, were analyzed for hSBEM mRNA expression by nested RT-PCR. Results： hSBEM mRNA expression was observed in 62/67 （92.54%） of breast cancer, 14/16 （87.50%） of breast benign lesions and 59/67 （88.05%） of normal breast tissue, with no significant differences between them （P 〉 0.05）. None of the samples from other cancer tissues were positive. In peripheral blood the expression of hSBEM mRNA was detected in 34/67 （50.75%） from patients with breast cancer, with significant increasing （P 〈 0.05） in the cases of metastatic disease （stage Ⅳ） and those with lymph node metastasis compared with localized disease （stage Ⅰ, Ⅱ and Ⅲ） and without lymph node metastasis, but its expression was not found in peripheral blood of patients with benign breast lesions or healthy volunteers. Although CD44V6 mRNA was significantly higher in breast cancer than in benign breast lesions tissue and normal breast tissue, its expression in peripheral blood show no significant difference （P 〉 0.05） in the patients with breast cancer （82.09%）, benign breast lesion （75.00%）, or healthy volunteers （70.00%）. The expressions of hSBEM mRNA and CD44V6 mRNA had no correlation with the age of the patients, size of primary tumor, histological type and estrogen or progestin receptor status （P 〉 0.05）. Conclusion： hSBEM mRNA, as assessed by nested RT-PCR, shows a mammary-specific and mammary-sensitive expression, and is a sensitive indicator of hematogeneous spread of breast cancer cell, while CD44V6 shows low sensitivity and specificity in detecting dissemination of breast cancer cell in peripheral blood, hSBEM mRNA is a promising molecular biomarker for detecting breast cancer micrometastases.

The clinical significance of hMAM mRNA expression in peripheral blood of patients with breast cancer

Objective: To study the clinical significance of human mammaglobin (hMAM) mRNA in peripheral blood of patients with breast cancer. Methods: The expression of hMAM mRNA was detected in peripheral blood from patients with breast cancer, breast benign lesions, healthy volunteers by nested reverse transcription polymerase chain reaction (nested-RT-PCR) method. The possible correlations of hMAM mRNA expression with clinico-pathological parameters and related molecular markers such as p53, PCNA and HER-2 were analyzed. The hMAM mRNA changed in peripheral blood after chemotherapy was observed. Results: The positive rate of hMAM mRNA was 34.0% in peripheral blood of breast cancer, hMAM mRNA was not expressed in peripheral blood from other cancers, breast benign lesions or healthy volunteers. The expression of hMAM mRNA in peripheral blood was correlated with lymph nodes status and TNM stage. After 2-3 cycles adjuvant chemotherapy, In 13 of 17 cases, the positive hMAM mRNA turned to be negative, and there was statistical difference between pre-chemo- therapy and post-chemotherapy. Conclusion: hMAM mRNA has specific expression in breast cancer, the positive expression of hMAM mRNA in peripheral blood might predict hematogenous metastatic spreading of tumor cells, and hMAM mRNA may be potential biological marker for detecting breast cancer micrometastasis.