Expression of calpain small subunit 1 in breast cancer and its clinical significance / 肿瘤研究与临床

Objective To investigate the expression of calpain small subunit 1 (Capn4) in breast cancer and its clinical significance. Methods The cancer tissues and the paraffin-embeded specimens of the corresponding adjacent normal tissues from 12 patients with breast cancer between May 2015 and July 2015 in Shanghai General Hospital were collected. The expression of Capn4 was detected by using immunohistochemistry. The paraffin-embeded specimens of cancer tissues from 70 breast cancer patients in Shanghai General Hospital between January 2009 and September 2011 were also collected. And the expression of Capn4 was detected. The correlation between Capn4 expression level and TNM stage, pathological grade, molecular markers as well as the prognosis of breast cancer was also analyzed. Results The expression of Capn4 in breast cancer tissues was higher than that in the corresponding adjacent normal tissues. The expression level of Capn4 was correlated with TNM stage (P = 0.002), T stage (P = 0.004), N stage (P = 0.004), M stage (P = 0.025), estrogen receptor (ER) status (χ 2 = 4.787, P = 0.029) and survival status (χ 2 = 5.826, P = 0.016). Kaplan-Meier survival analysis revealed that the median survival time in the higher expression of Capn4 group 90 months was shorter than that in the lower expression of Capn4 group (not reaching the median survival time), and there were statistical differences (χ 2 = 4.351, P = 0.037). Conclusions The expression of Capn4 in breast cancer tissues is upregulated. The expression difference is correlated with TNM stage, pathological grade, ER status and the prognosis of breast cancer, suggesting that it may become a new target and molecular marker for breast cancer treatment.

Impacts of ethanol on the epidermal growth factor receptor (EGFR) -calpain signaling and migration in breast cancer cells / 中国癌症杂志

Background and purpose:Ethanol has been reported to stimulate progression of breast cancer, yet the underlying mechanism is not fully understood. This study aimed to investigate effects of ethyl alcohol (EtOH) on the calcium-activated neutral protease (CANP)-cyclin E/focal adhesion kinase (FAK) signaling and cell migration in breast cancer cells, as well as the role of epidermal growth factor receptor (EGFR) in the EtOH-stimulated effects, in order to assess the signaling mechanism(s) underlying how EtOH enhances cancer progression.Methods:Human breast cancer cell line MCF-7 was employed as a model system, with MCF-10A mammary epithelial cells as control. In vitro wound healing assay was carried out to evaluate EtOH-induced cell migration. The effects of EtOH or epidermal growth factor on the proteolysis of cyclin E/FAK were detected by Western blot. EGFR inhibitor (EGFR-I) and a speciifc inhibitor for CANP, Calpeptin, were applied to pretreat cultured cells to explore their inlfuences on the cell migration and cyclin E/FAK proteolysis triggered by EtOH.Results:Treatment of model cells with EtOH (0.3%) stimulated significant proteolysis of cyclin E/FAK in a dose-/time-dependent manner and increased migration (+47.30%,P<0.05) in MCF-7 breast cancer cells, but had no signiifcant effect on migration in MCF-10A cells. Pretreatment with Calpeptin (10 μmol/L) signiifcantly reduced EtOH (0.3%)- or EGFR (10 ng/mL)-induced cyclin E/FAK truncation. EGFR-I (3 μmol/L) pro-foundly reduced EtOH-indcued CANP dependent proteolysis of CANP1 and cyclin E/FAK as well as cell migration (-53.00%,P<0.01).Conclusion:EtOH signiifcantly stimulates activation of CANP via EGFR pathway, resulting in proteolysis of cyclin E/FAK and migration in MCF-7 breast cancer cells, suggesting EGFR-CANP signaling to be a potential target for suppression of metastasis in breast cancer.

Characterization of novel extracellular protease produced by marine bacterial isolate from the Indian Ocean

Out of the vast pool of enzymes, proteolytic enzymes from microorganisms are the most widely used in different industries such as detergent, food, peptide production etc. Several marine microorganisms are known to produce proteases with commercially desirable characteristics. We have isolated nine different cultures from marine samples of the Indian Ocean. All of them were i) motile ii) rod shaped iii) non spore forming iv) catalase and amylase positive v) able to grow in presence of 10 percent NaCl. They produced acid from glucose, fructose and maltose and grew optimally at 30 0C temperature and pH 7.0-8.0. None of them could grow above 45 0C and below 15 0C. Only one of them (MBRI 7) exhibited extracellular protease activity on skim milk agar plates. Based on 16S rDNA sequencing, it belonged to the genus Marinobacter (98 percent sequence similarity, 1201 bp). The cell free extract was used to study effects of temperature and pH on protease activity. The optimum temperature and pH for activity were found to be 40 0C and 7.0 respectively. The crude enzyme was stable at temperature range of 30-80 0C and pH 5.0-9.0. It retained 60 percent activity at 80 0C after 4 h and more than 70 percent activity at 70 0C after 1 h. D value was found to be 342 minutes and 78 minutes for 40 0C and 80 0C respectively. Interestingly the enzyme remained 50 percent active at pH 9.0 after 1 h. Comparison with other proteases from different microbial sources indicated that the neutral protease from the halotolerant marine isolate MBRI 7 is a novel enzyme with high thermostability.

Purification and Properties of Neutral Protease from Bacillus Subtilis ZC-7 / 中国生物工程杂志

Bacillus subtilis ZC-7 was obtained by implantation with N+ ions beam to B.subtilis AS1.398,and compared with the AS1.398 neutral protease,the enzyme activity of ZC-7 neutral protease was about 1 timeshigher in previous research.A neutral protease was purified from the culture of B.Subtilis ZC-7 by the procedures including amoninium sulfate precipitation,ultrafiltration,DEAE-Sepharose Fast Flow chromatography and Sephadex G-75 chromatography.By multi-step purification,the ZC-7 neutral protease was purified to 78.5 folds and its yield was 27.7%,at last,the specific activity of ZC-7 neutral protease was up to 4.1?105U/mg.Analysed by SDS-PAGE,the purified protease has shown a molecular mass of about 42kDa.The Km for casein hydrolysis was 3.67?10-3?g/ml and the Vmax was 12.21?g/min.The optimum pH and temperature forhydrolysis of casein were 7.0 and 55℃,respectively.This protease was stable up to 40℃ within the pH range of 6.5 and 8.0.EDTA,isopropanol and alcohol nearly inhibited its activity while some ions such as Ca2+,Mg2+,Fe3+ can improve its activity.In addition,it could resist 1 mol/L H2O2.

Construction of an Inducible Expression and Secretion System for Neutral Protease in Bacillus subtilis / 中国生物工程杂志

The promoter and signal peptide sequence of sacB gene (sacR gene) has been amplified by PCR.An inducible expression and secretion vector pHP13SN has been constructed with this amplified sequence,which was ligated with the pro-peptide and mature peptide of neutral protease gene on the vector pHP13.Transforming Bacillus subtilis DB104 with the vector pHP13SN, and the recombinant strain DB104(pHP13SN) can be got.The neutral protease gene has been expressed by the inducement of sucrose and the regulation of sacR,and the production has been secreted with bioactivity.