DCTPP1, an Oncogene Regulated by miR-378a-3p, Promotes Proliferation of Breast Cancer via DNA Repair Signaling Pathway.

Breast cancer (BRCA) is one of the most deadly cancers worldwide, with poor survival rates that could be due to its high proliferation. Human all-alpha dCTP pyrophosphatase 1 (DCTPP1) is implicated in numerous diseases, including cancers. However, its role in BRCA is unclear. In this study, we used bioinformatic analyses of the ONCOMINE, UALCAN, and GEPIA databases to determine the expression pattern of DCTPP1 in BRCA. We found that elevated DCTPP1 levels correlate with poor BRCA prognosis. DCTPP1 silencing inhibited BRCA cell proliferation and induced apoptosis in vitro, as well as in vivo. Our data show that this tumorigenic effect depends on DNA repair signaling. Moreover, we found that DCTPP1 is directly modulated by miR-378a-3p, whose downregulation is linked to BRCA progression. Our results showed down-regulation of miR-378a-3p in BRCA. Upregulation of miR-378a-3p, on the other hand, can inhibit BRCA cell growth and proliferation. This study shows that reduced miR-378a-3p level enhances DCTPP1 expression in BRCA, which promotes proliferation by activating DNA repair signaling in BRCA.

A novel panel of serum miR-21/miR-155/miR-365 as a potential diagnostic biomarker for breast cancer.

PURPOSE: Insufficient sensitivity and specificity prevent the use of most existing biomarkers for early detection of breast cancer. Recently, it was reported that serum microRNAs (miRNAs) may be potential biomarkers in many cancer diseases. In this study, we investigated whether serum levels of 5 miRNAs including miR-21, miR-125b, miR-145, miR-155, and miR-365 could discriminate breast cancer patients and healthy controls. METHODS: Serum levels of miRNAs were measured by using quantitative real-time polymerase chain reaction in 99 breast cancer patients and 21 healthy controls. The abundance change of serum miRNAs were also evaluated following surgical resection in 20 breast cancer patients. Receiver operating characteristic (ROC) curve analysis was performed to assess the sensitivity and specificity of miRNAs as diagnostic biomarkers. RESULTS: Serum levels of miR-21 and miR-155 was significantly higher, while miR-365 was significantly lower in breast cancer as compared with healthy controls. The serum levels of miR-21 and miR-155 significantly decreased following surgical resection. Additionally, the serum level of miR-155 at stages I and II was significantly higher compared to stage III. The serum miR-145 level was remarkably higher in progesterone receptor (PR)-positive patients than PR-negative. The positivity of miR-21, miR-155, and miR-365 was high compared to CA 153 and CEA in breast cancer. ROC curve analyses of a combination of miR-21, miR-155, and miR-365 yielded much higher area under curve and enhanced sensitivity and specificity in comparison to each miRNA alone. CONCLUSION: The combination of serum miR-21/miR-155/miR-365 may potentially serve as a sensitive and specific biomarker that enables differentiation of breast cancer from healthy controls.

Expression of tissue levels of matrix metalloproteinases and their inhibitors in breast cancer.

BACKGROUND: We examined mRNA expression for MMP-2, MMP-7, MMP-9, MT1-MMP, TIMP-1, and TIMP-2 in human breast cancer tissues, and the association between their expression and clinicopathological variables. PATIENTS AND METHODS: Breast tissue samples from 120 patients with breast cancer were available for this study. To determine mRNA expression for MMP-2, MMP-7, MMP-9, MT1-MMP, TIMP-1, and TIMP-2, semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) was carried out on tumor and normal tissues, respectively. RESULTS: Mean MMP-2, MMP-7, MMP-9, MT1-MMP, TIMP-1, and TIMP-2 mRNA expression in the breast cancer was significantly higher than in the normal tissue. In terms of tumor size and lymph node metastasis of breast cancer, the differences in MMP-2, MMP-7, MMP-9, and MT1-MMP mRNA expression levels were significant. CONCLUSION: The association between the increased expression of MMP-2, MMP-7, MMP-9, and MTI-MMP and clinicopathological parameters reflects a role in predicting the aggressive behavior of breast cancer.

Clinicopathologic characteristics and prognosis of young patients with breast cancer.

BACKGROUND: The aim was to describe the clinicopathological features and prognosis of young patients with breast cancer. PATIENTS AND METHODS: We reviewed the records of 1478 consecutive patients aged ≤50 years with first diagnosis of invasive breast cancer referred to surgery from January 1999 to March 2005. A total of 174 patients were aged <35 years (group I) and 1304 were aged 35-50 years (group II). RESULTS: Compared with patients of group II, patients of group I had a higher percentage of tumors classified as estrogen receptors (ER) negative, progesterone receptors (PR) negative, with a Ki-67 labeling index ≥20% of the cells. The 5-year survival of group I was 78.3% as compared with 84.2% for group II (P = 0.006). CONCLUSION: Compared with patients aged between 35 and 50 years, patients aged <35 years have a greater chance of having an endocrine-unresponsive tumor and a significantly poor prognosis.

[Reversal effect and mechanism of arsenic trioxide on multidrug resistance of gastric carcinoma cells SGC7901].

The purpose of this study is to investigate the reversal effect and its mechanism of arsenic trioxide (As2O3) on multidrug resistance of gastric carcinoma cells. The concentration of vincristine (VCR) increased gradually to induce the drug resistance of gastric carcinoma cell SGC7901. MTT assay was used to determine the lethal effect of anticarcinogens on tumor cells and Western blotting assay was applied to determine the expression of P-glucoprotein (P-gp) and glutathione S-transferase (GST-s) in tumor cells. As a result, the resistance of SGC7901/VCR cells to VCR, fluorouracil and epirubicin was 16.56, 2.69 and 13.05 times, respectively, more than that of SGC7901 cells. After 24 h precondition with As2O3, RI of vincristine, fluorouracil and epirubicin decreased significantly (P < 0.05). Expression of P-gp and GST-s in resting SGC7901/VCR cells was significantly higher than that in carcinogen-sensitive SGC7901 cells. As2O3 decreased the expression of P-gp and GST-s in SGC7901/VCR cells significantly, while it showed no significant effect on carcinogen-sensitive SGC7901 cells. The result suggested that As2O3 could partly reverse drug resistance of SGC7901/VCR cells by probably the mechanism of decreasing the expression of P-gp and GST-s.