Annexin A1 promotes the nuclear localization of the epidermal growth factor receptor in castration-resistant prostate cancer

Epidermal growth factor receptor is a cancer driver whose nuclear localization has been associated with the progression of prostate cancer to the castration-resistant phenotype. Previous reports indicated a functional interaction between this receptor and the protein Annexin A1, which has also been associated with aggressive tumors. The molecular pathogenesis of castration-resistant prostate cancer remains largely unresolved, and herein we have demonstrated the correlation between the expression levels and localization of the epidermal growth factor receptor and Annexin A1 in prostate cancer samples and cell lines. Interestingly, a higher expression of both proteins was detected in castration-resistant prostate cancer cell lines and the strongest correlation was seen at the nuclear level. We verified that Annexin A1 interacts with the epidermal growth factor receptor, and by using prostate cancer cell lines knocked down for Annexin A1, we succeeded in demonstrating that Annexin A1 promotes the nuclear localization of epidermal growth factor receptor. Finally, we showed that Annexin A1 activates an autocrine signaling in castration-resistant prostate cells through the formyl peptide receptor 1. The inhibition of such signaling by Cyclosporin H inhibits the nuclear localization of epidermal growth factor receptor and its downstream signaling. The present work sheds light on the functional interaction between nuclear epidermal growth factor receptor and nuclear Annexin A1 in castration-resistant prostate cancer. Therefore, strategies to inhibit the nuclear localization of epidermal growth factor receptor through the suppression of the Annexin A1 autocrine loop could represent an important intervention strategy for castration-resistant prostate cancer.

Does sleep influence weight gain during pregnancy? A prospective study

Objective

The focus of this study was to evaluate the associations between subjective sleep quality and duration and weight gain during pregnancy.

Methods

A prospective and longitudinal study was conducted with 63 pregnant women. Pregnant women were evaluated at the first, second and third trimester for subjective sleep quality (Pittsburgh Sleep Quality Index [PSQI]) and anthropometric variables for body mass index [BMI] calculation. The sleep quality was grouped per cluster, identifying those individuals who maintained, improved or worsened their sleep quality, based on the PSQI classifications. Generalized estimating equations (GEE) were used to examine the association between sleep and BMI over the pregnancy period.

Results

An effect of the interaction between time of pregnancy and clusters of sleep quality was observed on the BMI (p<0.05), which indicates that pregnant women who improved subjective sleep quality during pregnancy gained more weight from the second to third trimester, while those that worsened the subjective sleep quality gained more weight during the first to second trimester. Sleep duration was not associated with weight gain. However, pregnant women who maintained the same BMI category over the pregnancy period increased their sleep duration from the first to third trimester, while those that increased the BMI category slept the same amount of time during this period (median=1.0 [0.0-2.0] and median=0.0 [-2.0-1.0], respectively, p=0.039).

Conclusions

The authors concluded that a worse subjective sleep quality seems to lead to an inadequate weight gain distribution during the period of pregnancy.

A novel breast cancer screening platform: An epitope-based biomarker coupled to electrochemical sensor

9

Background: The subtractive proteomic selection technology called Phage Display (PD) has been extensively used by our group in the discovery of high affinity ligands to target tissues and molecules. We have selected specific ligands against IgG purified from BC tissues, which was successfully coupled to an electrochemical sensor to detect the tumor-specific immune response. Methods: After PD selections, all immunoreactive peptide ligands were further characterized by DNA sequencing, in vitro translated and submitted to bioinformatic analyses. Further validations were performed by ELISA. We then used one synthetic peptide (SF4) for the construction of an immunosensor, which was applied to patients and control samples for final validation. Electrochemical impedance spectroscopy (EIS) was performed. Results: We have selected the F4 peptide for final validation and sensor construction due to its capability of detecting IgG in the peripheral blood and the excellent ELISA ratio BC:BBD, discriminating more than 70% of BC patients. The synthetic peptide reached a good precision in BC diagnosis (68%), but surprisingly, the selected F4 clone presented the highest sensitivity and specificity, (77.8% and 85.7%, respectively), suggesting that it can be used as a diagnostic reagent for early BC screening prior to imaging and pathological analyses. The electrochemical sensor that was built with the epitope-based peptide discriminated all IgG from BC and healthy individuals. Results with the EIS sensor demonstrated that the presence of (SF4) peptide IgG generated higher resistivity (-Z ') compared to the system containing only the peptide or the control sera. This is justified by the fact that with the immobilized biological peptide layer was correctly conjugated with the IgG forming an antigen: antibody complex that led to an increased resistance to the charge transfer system, producing a decrease in electron transfer between the iron-coupled / ferricyanide redox and the electrode surface. Conclusions: An electrochemical sensor using an epitope-based biomarker was developed, which allows for the first time BC screening using a very simple platform that could be an important auxiliary tool to mammography imaging.

A putative OTU domain-containing protein 1 deubiquitinating enzyme is differentially expressed in thyroid cancer and identifies less-aggressive tumours

Background:

This study aimed to identify novel biomarkers for thyroid carcinoma diagnosis and prognosis.

Methods:

We have constructed a human single-chain variable fragment (scFv) antibody library that was selected against tumour thyroid cells using the BRASIL method (biopanning and rapid analysis of selective interactive ligands) and phage display technology.

Results:

One highly reactive clone, scFv-C1, with specific binding to papillary thyroid tumour proteins was confirmed by ELISA, which was further tested against a tissue microarray that comprised of 229 thyroid tissues, including: 110 carcinomas (38 papillary thyroid carcinomas (PTCs), 42 follicular carcinomas, 30 follicular variants of PTC), 18 normal thyroid tissues, 49 nodular goitres (NG) and 52 follicular adenomas. The scFv-C1 was able to distinguish carcinomas from benign lesions (P=0.0001) and reacted preferentially against T1 and T2 tumour stages (P=0.0108). We have further identified an OTU domain-containing protein 1, DUBA-7 deubiquitinating enzyme as the scFv-binding antigen using two-dimensional polyacrylamide gel electrophoresis and mass spectrometry.

Conclusions:

The strategy of screening and identifying a cell-surface-binding antibody against thyroid tissues was highly effective and resulted in a useful biomarker that recognises malignancy among thyroid nodules and may help identify lower-risk cases that can benefit from less-aggressive management.