The roles of protocadherin-7 in colorectal cancer cells on cell proliferation and its chemoresistance.

Despite the high mutation frequencies of KRAS, NRAS, and BRAF in colorectal cancer (CRC), there are no effective and reliable inhibitors for these biomarkers. Protocadherin-7 (PCDH7) is regarded as a potentially targetable surface molecule in cancer cells and plays an important role in their proliferation, metastasis, and drug resistance. However, the roles and underlying mechanisms of PCDH7 in CRC remain unclear. In the current study, we found that different colorectal cancer cells expressed PCDH7 over a wide range. The levels of PCDH7 expression were positively associated with cell proliferation and drug resistance in CRC cells but negatively correlated with the potential for cell migration and invasion. Our data indicated that PCDH7 mediated the resistance of CRC cells to ABT-263 (a small-molecule Bcl-2 inhibitor that induces apoptosis) by inhibiting cell apoptosis, which was supported by the downregulation of caspase-3, caspase-9, and PARP cleavage. We found that PCDH7 effectively promoted Mcl-1 expression at both mRNA and protein levels. Furthermore, PCDH7 activated the Wnt signaling pathway, which was confirmed by the increase in ß-catenin and c-Myc expression. Finally, and notably, S63845, a novel Mcl-1 inhibitor, not only effectively attenuated the inhibitory effect of PCDH7 on cell apoptosis induced by ABT-263 in vitro but also sensitized PCDH7-overexpressed CRC cell-derived xenografts to ABT-263 in vivo. Taken together, although PCDH7 inhibited the migration and invasion of CRC cells, it could facilitate the development of drug resistance in colorectal cancer cells by positively modulating Mcl-1 expression. The application of the Mcl-1 inhibitor S63845 could be a potential strategy for CRC chemotherapy, especially in CRC with high levels of PCDH7.

AEBP1 Contributes to Breast Cancer Progression by Facilitating Cell Proliferation, Migration, Invasion, and Blocking Apoptosis.

BACKGROUND: The aberrant expression of adipocyte enhancer binding protein 1 (AEBP1) has been observed in many cancers and it seems to be involved in the tumorigenesis, progression, and metastasis in numerous tumor types. However, the contribution of AEBP1 in breast cancer (BCa) remains inexplicable. METHODS: Information related to the diagnostic significance and expression of AEBP1 in BCa was obtained from the public dataset Kaplan-Meier Plotter (http://kmplot.com/analysis/) and the dataset UALCAN (https://ualcan.path.uab.edu/index.html). The MTT (methyl thiazolyl tetrazolium) assay, colony formation assay, Transwell® assay, and FACS (fluorescence-activated cell sorting) assay were used to detect the proliferation, invasive and apoptotic ability of cells before and after treatment. In addition, we constructed an AEBP1 overexpression vector and silenced AEBP1, combined with Real-Time Quantitative Reverse Transcription PCR (qRT-PCR), western blot, immunohistochemistry and TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling) assay to investigate the prognostic significance, biological functions and potential mechanisms of AEBP1 in BCa. RESULTS: Higher expression of AEBP1 mRNA (message RNA) was observed in BCa patients with later-stage, who obtained poorer overall survival. Meanwhile, compared with adjacent noncancerous tissues, AEBP1 protein expression was dramatically upregulated in the BCa ones. Furthermore, overexpressed AEBP1 enhanced cell proliferation, migration, invasion, and blocked cell apoptosis in BCa cells. Moreover, the research certificated that AEBP1 upregulated the expression of MMP (matrix metalloproteinase)-2, 9, vimentin, N-cadherin (neural-cadherin), phosphorylation of ERK (extracellular signal-regulated kinase), Smad2/3 (Abbreviated from Sma for nematode and Mad for Drosophila) and AKT (V-akt murine thymoma viral oncogene homolog), while down-regulated the expression of E-cadherin (epithelial cadherin) and PTEN (phosphatase and tensin homolog deleted on chromosome 10). To inhibit cell apoptosis, enforced expression of AEBP1 effectively blocked the cleavage of caspase 9 and p53 (protein 53) and promoted the expression of anti-apoptotic protein Bcl-2 (B-cell lymphoma-2). Finally, AEBP1 accelerated subcutaneously transplanted tumor growth in nude mice by increasing the expression of the cell proliferation biomarker ki67, the phosphorylation of AKT, and blocked apoptosis in vivo. CONCLUSIONS: In summary, these data suggested the important role of AEBP1 in the BCa progression, which could be used as a potential biomarker for prognostic hallmark and a novel therapeutic strategy.

NRF3 suppresses breast cancer cell metastasis and cell proliferation and is a favorable predictor of survival in breast cancer.

Background: Cancer metastasis is the leading cause of cancer-related death in breast cancer. However, our understanding of its mechanisms is still limited. At this study, the biological roles and clinical significance of NRF3 (NFE2L3, nuclear factor, Erythroid 2 Like 3) in breast cancer are evaluated for the first time. Methods: NRF3 expression in breast cancer cell lines and clinical specimens was determined by western blot and immunohistochemistry, respectively. Cell proliferation, cell cycle distribution, cell migration, and invasion were detected by MTT, colony formation, flow cytometry, and transwell assays, respectively. All other proteins were measured by western blot. The clinical significance of NRF3 was analyzed using the data from tissue microarray. Results: We found that NRF3 expression was obviously suppressed in breast cancer tissues, and negatively associated with the Lymph node metastasis status and tumor stages. Our data also indicated NRF3 expression was much higher in MCF-7 cells than that in MDA-MB-231 and SKBR3 cells which were more malignant. Silence of NRF3 in MCF-7 cells could significantly promote cell proliferation by reducing the cell number in the G0/G1 phase. Exogenous expression of NRF3 in SKBR3 and MDA-MB-231 cells effectively inhibited both cell growth and metastasis with epithelial-mesenchymal transition and MMPs expression suppressed. NRF3 overexpression also impaired the ID3 expression by inactivating the AKT signaling pathway. Exogenous expression of ID3 could not only effectively promote breast cancer cell invasion by inhibiting E-cadherin expression and upregulating MMP-2 expression, but also attenuated the inhibitory function of NRF3 on the breast cancer cell invasion. Conclusion: Our findings suggested that NRF3 inhibited breast cancer cell proliferation and metastasis via inhibiting AKT/ID3 axis at least partially, and potentially to be a valuable clinic marker in breast cancer prognosis.

Fenofibrate potentiates chemosensitivity to human breast cancer cells by modulating apoptosis via AKT/NF-κB pathway.

BACKGROUND: Cumulatively, evidences revealed that fenofibrate used in the therapy of hyperlipidemia and hypercholesterolemia has anti-cancer effect in multiple cancer types. However, its function and underlying mechanism of chemosensitization in breast cancer remain poorly understood. MATERIALS AND METHODS: The cytotoxicity of fenofibrate and anti-cancer drugs in breast cancer cells was determined by MTT. Apoptosis and mitochondrial membrane potential were measured using flow cytometry. Caspases and PARP cleavage, the Bcl-2 family members' protein expression, as well as the activation of AKT and NF-κB signaling pathways were evaluated using Western blot assay. Real-time PCR was used to determine the mRNA expression of Bcl-2 family members. RESULTS: Our data indicated that fenofibrate suppressed SKBR3 and MDA-MB-231 cell growth in a dose-dependent manner, in the same way as paclitaxel, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), ABT-737, and doxorubicin. Subtoxic levels of fenofibrate significantly augmented paclitaxel, TRAIL, ABT-737, and doxorubicin-induced apoptosis in both these two cell lines. Fenofibrate-promoted chemosensitivity is predominantly mediated by caspase-9 and caspase-3 activation and mitochondrial outer membrane permeabilization. Meanwhile, chemosensitivity promoted by fenofibrate also increased the expression of Bax and Bok and decreased the expression of Mcl-1 and Bcl-xl. Mechanistically, fenofibrate effectively reduced the phosphorylation levels of AKT and NF-κB. In addition, imiquimod, an NF-κB activator, could reverse fenofibrate-induced susceptibility to ABT-737-triggered apoptosis. CONCLUSION: The present study provided the evidence of the underlying mechanisms on chemosensitization of fenofibrate by inducing the apoptosis of breast cancer in an AKT/NF-κB-dependent manner and implicated the potential application of fenofibrate in potentiating chemosensitivity in breast cancer therapy.

Breast cancer metastasis suppressor gene, breast cancer metastasis suppressor 1, may be associated with clinicopathological features of breast cancer.

OBJECTIVE: We aim to investigate whether the breast cancer metastasis suppressor gene, breast cancer metastasis suppressor 1 (BRMS1), is correlated with clinicopathological features of breast cancer or not. MATERIALS AND METHODS: Following a stringent inclusion and exclusion criteria, case-control studies related to the association between BRMS1 and breast cancer were selected from articles retrieved by electronic database searches. All statistical analyses were performed by Stata version 12.0 (Stata Corp, College Station, TX, USA). RESULTS: A total of 12 studies were ultimately included in this meta-analysis. Results of our meta-analysis suggested that BRMS1 protein in breast cancer tissues was significantly lower compared with normal breast tissues (odds ratio [OR] =0.08, 95% confidence interval [CI] =0.04-0.15, P < 0.001). The BRMS1 protein in metastatic breast cancer tissue was lower than that in nonmetastatic breast cancer tissue (OR = 0.20, 95% CI = 0.13-0.29, P < 0.001), and BRMS1 protein in tumor-node-metastasis (TNM) stages 1, 2 was found to be higher than TNM stages 3, 4 (OR = 4.62, 95% CI = 2.77-7.70, P < 0.001). With respect to breast cancer types, BRMS1 protein in all the three major types of breast cancer was lower than the normal tissues. We also found strong correlations between BRMS1 mRNA levels and TNM stage and tumor size. CONCLUSION: Our meta-analysis results showed that reduced BRMS1 expression level was significantly associated with clinicopathological features of breast cancer, suggesting that loss of expression or reduced levels of BRMS1 might be a strong indicator of the metastatic capacity of breast cancer, with poor prognosis.

BRMS1 gene expression may be associated with clinico-pathological features of breast cancer.

Our aim is to investigate whether or not the breast cancer metastasis suppressor 1 (BRMS1) gene expression is directly linked to clinico-pathological features of breast cancer. Following a stringent inclusion and exclusion criteria, case-control studies with associations between BRMS1 and breast cancer were selected from articles obtained by way of searches conducted through an electronic database. All statistical analyses were performed with Stata 12.0 (Stata Corp, College Station, TX, U.S.A.). Ultimately, 1,263 patients with breast cancer were found in a meta-analysis retrieved from a total that included 12 studies. Results of our meta-analysis suggested that BRMS1 protein in breast cancer tissues was significantly lower in comparison with normal breast tissues (odds ratio, OR = 0.08, 95% confidence interval (CI) = 0.04-0.15). The BRMS1 protein in metastatic breast cancer tissue was decreased than from that was found in non-metastatic breast cancer tissue (OR = 0.20, 95%CI = 0.13-0.29), and BRMS1 protein in tumor-node-metastasis (TNM) stages 1 and 2 was found to be higher than TNM stages 3 and 4 (OR = 4.62, 95%CI = 2.77-7.70). BRMS1 protein in all three major types of breast cancer was lower than that of control tissues respectively. We also found strong correlations between BRMS1 mRNA levels and TNM stage and tumor size. The results our meta-analysis showed that reduction in BRMS1 expression level was linked directly to clinico-pathological features of breast cancer significantly; therefore, suggesting the loss of expression or reduced levels of BRMS1 is potentially a strong indicator of the metastatic capacity of breast cancer with poor prognosis.

Serum expression levels of microRNA-382-3p, -598-3p, -1246 and -184 in breast cancer patients.

The purpose of the present study was to investigate the serum levels of microRNA (miRNA/miR)-382-3p, -598-3p, -1246 and -184 in breast cancer patients and to assess their feasibility as biomarkers for breast cancer screening. Serum samples were obtained from 100 breast cancer patients and 40 age-matched healthy control subjects in Taizhou Central Hospital (Taizhou, Zhejiang, China) between January 2013 and September 2014. The serum expression levels of miR-382-3p, -598-3p, -1246 and -184 were determined by stem-loop reverse transcription-quantitative polymerase chain reaction. Receiver operating characteristic curves were drawn to evaluate the sensitivity and specificity of the serum miRNA expression levels for the screening of breast cancer. miR-382-3p and -1246 were significantly upregulated in the serum of the breast cancer patients, while miR-598-3p and -184 were significantly downregulated. The sensitivity and specificity to detect breast cancer were as follows: miR-382-3p, 52.0 and 92.5%; miR-598-3p, 95.0 and 85.0%; miR-1246, 93.0 and 75.0%; and miR-184, 87.5 and 71.0%, respectively. The expression levels of the four serum miRNAs were not correlated with the patients' clinical stage. In summary, miR-382-3p, -598-3p, -1246 and -184 are all involved in the development of breast cancer, and are promising biomarkers for breast cancer detection.

Different miRNA expression profiles between human breast cancer tumors and serum.

A bunch of microRNAs (miRNAs) have been demonstrated to be aberrantly expressed in cancer tumor tissue and serum. The miRNA signatures identified from the serum samples could serve as potential noninvasive diagnostic markers for breast cancer. The role of the miRNAs in cancerigenesis is unclear. In this study, we generated the expression profiles of miRNAs from the paired breast cancer tumors, normal, tissue, and serum samples from eight patients using small RNA-sequencing. Serum samples from eight healthy individuals were used as normal controls. We identified total 174 significantly differentially expressed miRNAs between tumors and the normal tissues, and 109 miRNAs between serum from patients and serum from healthy individuals. There are only 10 common miRNAs. This suggests that only a small portion of tumor miRNAs are released into serum selectively. Interestingly, the expression change pattern of 28 miRNAs is opposite between breast cancer tumors and serum. Functional analysis shows that the differentially expressed miRNAs and their target genes form a complex interaction network affecting many biological processes and involving in many types of cancer such as prostate cancer, basal cell carcinoma, acute myeloid leukemia, and more.