ABSTRACT
Objective:To investigate the expressions of tissue inhibitor of matrix metalloproteinase-1 (TIMP1) and fibronectin 1 (FN1) in pregnancy associated breast cancer (PABC) and their correlations with expression of E-cadherin (E-cad).Methods:The clinicopathological data of 55 PABC patients in Binzhou People's Hospital Affiliated to Shandong First Medical University from January 2011 to December 2020 were retrospectively analyzed. Immunohistochemistry was used to detect expressions of TIMP1, FN1 and E-cad in cancer tissues and corresponding paracancerous tissues (>3 cm from the edge of the tumor foci). The expressions of TIMP1 and FN1 proteins in fresh intraoperative frozen cancer tissues and paracancerous tissues of 10 PABC patients were detected by Western blotting. The correlations of TIMP1 and FN1 expressions with clinicopathological characteristics of patients were analyzed by χ2 test, the correlation of TIMP1 and FN1 expressions with E-cad expression was analyzed by Spearman method, and the correlation of TIMP1 and FN1 expressions with survival was analyzed by Kaplan-Meier method. Results:The positive rates of TIMP1 and FN1 in PABC tissues were 72.7% (40/55) and 58.2% (32/55), and 25.5% (14/55) and 18.2% (10/55) in paracancerous tissues, and the differences were statistically significant ( χ2 values were 24.59 and 18.64, both P < 0.001). The results of Western blotting showed that the relative expressions of TIMP1 and FN1 proteins in the fresh cancer tissues of 10 PABC patients was higher than those in the corresponding paracancerous tissues (1.60±0.76 vs. 0.62±0.29, 1.31±0.62 vs. 0.44±0.15), and the differences were statistically significant ( t values were 5.92 and 4.86, both P < 0.001). The expressions of TIMP1 and FN1 in PABC tissues were correlated with estrogen receptor expression, Ki-67 positivity index, TNM stage and lymph node metastasis (all P < 0.05). The expressions of TIMP1 and FN1 were negatively correlated with expression of E-cad in PABC ( r values were -0.471 and -0.432, both P < 0.001). Five cases were lost to follow-up, and the remaining 50 cases had a median follow-up time of 43 months (12-90 months). Among the 50 cases, 36 cases were TMP1-positive and 29 cases were FN1-positive. The overall survival of TIMP1-negative group and FN1-negative group were better than those of the corresponding positive group ( χ2 values were 4.49 and 6.06, both P < 0.05); the median overall survival time of TIMP1-positive group and FN1-positive group were 51 months (95% CI 37-65 months) and 43 months (95% CI 32-53 months), while that of TIMP1-negative group and FN1-negative group were 89 months (95% CI 84-93 months) and 87 months (95% CI 85-92 months). Conclusions:TIMP1 and FN1 expressions are elevated in PABC tissues and negatively correlated with E-cad expression, TIMP1 and FN1 may be involved in PABC invasion through epithelial-mesenchymal transition and affect the prognosis of patients.