LAPTM4B Predicts Axillary Lymph Node Metastasis in Breast Cancer and Promotes Breast Cancer Cell Aggressiveness in Vitro.

PURPOSE: Lysosome-associated protein transmembrane-4 beta (LAPTM4B) is associated with the prognosis of several human malignancies. In this study, the role of LAPTM4B in the metastatic potential of breast cancer (BC) and its underlying molecular mechanisms were investigated. METHODS: The relationship between LAPTM4B expression and axillary lymph node metastasis was determined in 291 BC specimens by immunohistochemistry. The expression of LAPTM4B in paired BC cells was overexpressed and inhibited to analyse the role of LAPTM4B in the aggressiveness of BC. Cell proliferation, migration and invasion were assessed in vitro. Metastasis-related protein levels were detected through Western blot. RESULTS: Immunohistochemical staining demonstrated that high expression level of LAPTM4B was independently associated with axillary lymph node metastasis (odds ratio=2.428; 95%CI=1.333- 4.425; P=0.004). The LAPTM4B inhibition in MCF-7 cells inhibited cell proliferation, migration, invasion, and resulted in simultaneous downregulation of phosphorylated N-cadherin, vimentin, and upregulation of E-cadherin. By contrast, the LAPTM4B overexpression promoted cell proliferation, migration, invasion, and led to simultaneous upregulation of N-cadherin, vimentin, and downregulation of E-cadherin in T47D cells. CONCLUSIONS: High expression level of LAPTM4B predicts tumor metastatic potential in patients with BC. Our results provide the first evidence of the role of LAPTM4B as an Epithelial-mesenchymal transition (EMT) inducer that promotes aggressiveness in BC cells.

Overexpression of TNFAIP8 is associated with tumor aggressiveness and poor prognosis in patients with invasive ductal breast carcinoma.

Tumor necrosis factor α-induced protein 8 (TNFAIP8), a transcription factor nuclear factor κB-inducible, antiapoptotic and oncogenic molecule, is associated with prognosis of several human malignancies. However, the relationship between TNFAIP8 and the prognosis of the invasive ductal carcinoma (IDC) of the breast remains unclear. TNFAIP8 expression was evaluated using real-time polymerase chain reaction (PCR) and Western blot analysis in 20 fresh IDC tissues and immunohistochemical analysis in 351 paraffin-embedded IDC tissues. Real-time PCR and Western blot analysis demonstrated that both TNFAIP8 messenger RNA and protein were up-regulated in IDC tissues compared with the paired adjacent noncancerous tissues. Immunohistochemistry revealed that TNFAIP8 expression was significantly correlated with some clinicopathological factors, including axillary lymph node metastasis (P=.001), advanced TNM stage (P<.001), high histologic grade (P<.001), molecular subtype (P<.001), and postoperative recurrence (P<.001). Univariate and multivariate logistic regression analyses demonstrated that TNFAIP8 overexpression was strongly associated with axillary lymph node metastasis (odds ratio, 1.818; 95% confidence interval, 1.167-2.832; P=.008). Moreover, Kaplan-Meier analysis indicated that IDC patients with high TNFAIP8 expression had a shorter survival time than did those with low TNFAIP8 expression, and multivariate analysis indicated that TNFAIP8 was an independent prognostic factor for overall survival and disease-free survival in IDC (P=.041 and P=.020, respectively). Therefore, TNFAIP8 overexpression may contribute to tumor progression, and it may be a novel prognostic biomarker for the patients with IDC.

p53 accumulation is a strong predictor of recurrence in estrogen receptor-positive breast cancer patients treated with aromatase inhibitors.

Aromatase inhibitors have played a central role in endocrine therapy for estrogen receptor (ER)-positive breast cancer in postmenopausal women. However, factors predictive of the efficacy of aromatase inhibitors, and prognostic factors, both for early and late recurrence in women treated with adjuvant aromatase inhibitors have not been identified. Whole genome analysis identified that a TP53 gene mutation exists in ER-positive breast cancers, although the frequency of TP53 gene mutation in luminal tumors is lower compared with basal-like or human epidermal growth factor receptor type 2 (HER2)-positive breast cancers. We examined expression of p53, as well as ER, progesterone receptor, HER2 and Ki-67 using immunohistochemistry in postmenopausal ER-positive breast cancer patients who were treated with aromatase inhibitors as adjuvant endocrine therapy. There were 53 (21%) tumors that contained 10% or more p53-positive cells. High p53 expression was positively correlated with tumor grade, HER2 score and Ki-67 expression. Significant association was observed between disease-free survival and high p53 expression in multivariate analysis (P < 0.0001). Compared with women without recurrence, women with early recurrence had significantly higher p53 expression (P < 0.0001), as did women with late recurrence (P = 0.037). The present study demonstrates that p53 accumulation is a strong predictor of both early and late recurrence in ER-positive breast cancer patients treated with aromatase inhibitors as adjuvant endocrine therapy. TP53 gene alteration might be a key biological characteristic of ER-positive breast cancer.

Overexpression of LAPTM4B: an independent prognostic marker in breast cancer.

PURPOSE: Lysosome-associated protein transmembrane 4 beta (LAPTM4B), a novel oncoprotein, has been shown to be overexpressed in several human malignancies. Our purpose was to evaluate the expression of LAPTM4B in breast carcinoma and its significance, which was not previously studied by others. METHODS: Through immunohistochemistry, LAPTM4B expression was evaluated in 35 benign breast tumor specimens and 194 breast cancer specimens. The correlation of LAPTM4B expression with clinicopathological parameters was assessed using χ(2) analysis. The survival status of patients was analyzed using the Kaplan-Meier and log-rank tests. Cox regression was used for the multivariate analysis of prognostic factors. RESULTS: The immunohistochemistry results showed that the expression level of LAPTM4B in breast cancer cases was significantly higher than that in benign breast tumor tissues (P < 0.001). Moreover, statistical analysis also showed that high LAPTM4B expression was positively related to TNM stage, lymph node metastasis, and recurrence. Furthermore, it was also shown that patients with high LAPTM4B expression had significantly poorer overall survival and disease-free survival compared with patients with low expression of LAPTM4B (P = 0.019 and P = 0.005, respectively). Multivariate Cox regression analysis revealed that high LAPTM4B expression level was an independent prognostic factor for both overall survival and disease-free survival of patients with breast cancer (P = 0.041 and P = 0.023, respectively). CONCLUSIONS: Overexpression of LAPTM4B may contribute to the tumor progression and poor prognosis of breast cancer, thus testing the expression of LAPTM4B will be helpful for predicting prognosis in breast cancer.

Expression of MAC30 protein is related to survival and clinicopathological variables in breast cancer.

BACKGROUND AND OBJECTIVES: MAC30 is a protein with unknown function that is differentially expressed in certain malignancies. The aims of this study were to evaluate the relationship between MAC30 expression and clinicopathologic features while investigate the prognostic value of MAC30 expression in breast cancer. METHODS: Immunohistochemistry was used to examine MAC30 expression in 243 breast cancer tissues, meanwhile in 59 matched adjacent noncancerous tissues and 46 benign breast tumor tissues as controls. The correlation of MAC30 expression with clinicopathological parameters was assessed using χ(2) analysis. The Kaplan-Meier method and Cox proportional hazards model were used to predict factors with a significant independent prognostic value. RESULTS: MAC30 was overexpressed in breast cancer compared with matched adjacent noncancerous tissues and benign breast tumor (both P < 0.001). Moreover, MAC30 expression was correlated with tumor size, TNM stage, lymph node metastasis, and recurrence. Furthermore, it was shown that patients with high MAC30 expression had significantly poorer overall survival (OS) and disease-free survival (DFS; P = 0.002 and P = 0.007, respectively). Multivariate Cox regression analysis revealed that high MAC30 expression was an independent prognostic factor for both OS and DFS (P = 0.018 and P = 0.044, respectively). CONCLUSIONS: Overexpression of MAC30 was associated with tumor progression, recurrence, and poor survival in breast cancer. Testing expression of MAC30 will be helpful for predicting prognosis in breast cancer.

Induction of apoptosis by D-limonene is mediated by inactivation of Akt in LS174T human colon cancer cells.

D-limonene is recognized as a potential chemotherapeutic agent, however, the details of this mechanism remain unclear. In this study, we investigated the effects of d-limonene on colon cancer cell viability and its potential mechanism of action in vitro. After 48 h of treatment, d-limonene suppressed the viability of LS174T cells in a dose-dependent manner and caused a dose-dependent apoptotic cell death. D-limonene activated caspase-3 and -9 and PARP cleavage in a dose-dependent manner. Moreover, an increase in Bax protein and cytosol cytochrome c from mitochondria and a decrease in bcl-2 protein were observed following treatment with d-limonene. In addition, d-limonene decreased the levels of p-Akt (Ser473), p-Akt (Thr308) and p-GSK-3ß (Ser9), suggesting that d-limonene induced apoptosis via the mitochondrial death pathway and the suppression of the PI3K/Akt pathway.

The differences in CXCR4 protein expression are significant for the five molecular subtypes of breast cancer.

The aim was to investigate the expression of the CXCR4 protein in five molecular subtypes of breast cancer. The authors randomly selected the breast cancer paraffin-embedded specimens of the Affiliated Third Hospital of Harbin Medical University between 2007 and 2009. Details are as follows: basal-like subtype-ER (-), PR (-), C-erbB-2 (-), CK5/6 (+), n = 36; normal breast subtype-ER (-), PR (-), C-erbB-2 (-), CK5/6(-), n = 40; luminal A subtype-ER/PR (+), C-erbB-2 (-), n = 38; luminal B subtype-ER/PR (+), C-erbB-2 (+), n = 60; C-erbB-2 (+) subtype-ER (-), PR (-), C-erbB-2 (+), n = 58. Using the immunohistochemistry method, the authors detected the expression of the CXCR4 protein in the five subtypes. The CXCR4 protein expression in the basal-like subtype was the highest, and that in the luminal A subtype was the lowest. In terms of five molecular subtypes of breast cancer, the differences in CXCR4 protein expression were significant (p < .001). In terms of C-erbB-2 expression, tumor stage, and lymph node metastasis of breast cancer, the differences in CXCR4 protein expression were significant (p < .01).