scholarly journals Low-background Acyl-biotinyl Exchange Largely Eliminates the Co-isolation of Non-S-acylated Proteins and Enables Deep S-acylproteomic Analysis

2019 ◽  
Author(s):  
Bo Zhou ◽  
Yang Wang ◽  
Yiwu Yan ◽  
Javier Mariscal ◽  
Dolores Di Vizio ◽  
...  

ABSTRACTProteinS-acylation (also called palmitoylation) is a common post-translational modification whose deregulation plays a key role in the pathogenesis of many diseases. Acyl-biotinyl exchange (ABE), a widely used method for the enrichment ofS-acylated proteins, has the potential of capturing the entireS-acylproteome in any types of biological samples. Here, we showed that current ABE methods suffer from high background arising from the co-isolation of non-S-acylated proteins. The background can be substantially reduced by an additional blockage of residual free cysteine residues with 2,2’-dithiodipyridine prior to biotin-HPDP reaction. Coupling the low-background ABE (LB-ABE) method with label-free quantitative proteomics, 2,895 high-confidence candidateS-acylated proteins (including 1,591 knownS-acylated proteins) were identified from human prostate cancer LNCaP cells, representing so-far the largestS-acylproteome dataset identified in a single study. Immunoblotting analysis confirmed theS-acylation of five known and five novel prostate cancer-relatedS-acylated proteins in LNCaP cells and suggested that theirS-acylation levels were about 0.6-1.8%. In summary, the LB-ABE method largely eliminates the co-isolation of non-S-acylated proteins and enables deepS-acylproteomic analysis. It is expected to facilitate much more comprehensive and accurate quantification ofS-acylproteomes than previous ABE methods.

2015 ◽  
Vol 69 (1) ◽  
Author(s):  
Stefan Belicky ◽  
Jan Tkac

AbstractGlycans are chains of carbohydrates attached to proteins (glycoproteins and proteoglycans) or lipids (glycolipids). Glycosylation is a post-translational modification and glycans have a wide range of functions in the human body including involvement in oncological diseases. Change in a glycan structure can not only indicate the presence of a pathological process but, more importantly, in some cases also its stage. Thus, a glycan analysis has the potential to be an effective and reliable tool in cancer diagnostics. Lectins are proteins responsible for natural biorecognition of glycans; even carbohydrate moieties still attached to proteins or whole cells can be recognised by lectins, which makes them an ideal candidate for designing label-free biosensors for glycan analysis. This review seeks to summarise evidence that the glycoprofiling of biomarkers by lectin-based biosensors can be of significant help in detecting prostate cancer.


1992 ◽  
Vol 68 (06) ◽  
pp. 662-666 ◽  
Author(s):  
W Hollas ◽  
N Hoosein ◽  
L W K Chung ◽  
A Mazar ◽  
J Henkin ◽  
...  

SummaryWe previously reported that extracellular matrix invasion by the prostate cancer cell lines, PC-3 and DU-145 was contingent on endogenous urokinase being bound to a specific cell surface receptor. The present study was undertaken to characterize the expression of both urokinase and its receptor in the non-invasive LNCaP and the invasive PC-3 and DU-145 prostate cells. Northern blotting indicated that the invasive PC-3 cells, which secreted 10 times more urokinase (680 ng/ml per 106 cells per 48 h) than DU-145 cells (63 ng/ml per 106 cells per 48 h), had the most abundant transcript for the plasminogen activator. This, at least, partly reflected a 3 fold amplification of the urokinase gene in the PC-3 cells. In contrast, urokinase-specific transcript could not be detected in the non-invasive LNCaP cells previously characterized as being negative for urokinase protein. Southern blotting indicated that this was not a consequence of deletion of the urokinase gene. Crosslinking of radiolabelled aminoterminal fragment of urokinase to the cell surface indicated the presence of a 51 kDa receptor in extracts of the invasive PC-3 and DU-145 cells but not in extracts of the non-invasive LNCaP cells. The amount of binding protein correlated well with binding capacities calculated by Scatchard analysis. In contrast, the steady state level of urokinase receptor transcript was a poor predictor of receptor display. PC-3 cells, which were equipped with 25,000 receptors per cell had 2.5 fold more steady state transcript than DU-145 cells which displayed 93,000 binding sites per cell.


2020 ◽  
Author(s):  
Lungwani Muungo

The androgen receptor (AR) plays a critical role in the development and the progression of prostate cancer. Alterations in theexpression of AR coregulators lead to AR hypersensitivity, which is one of the mechanisms underlying the progression ofprostate cancer into a castrate-resistant state. Octamer transcription factor 1 (Oct1) is a ubiquitous member of the POUhomeodomainfamily that functions as a coregulator of AR. In our study, the contribution of Oct1 to prostate cancerdevelopment was examined. Immunocytochemistry analysis showed that Oct1 is expressed in the nuclei of LNCaP cells.siRNA-mediated silencing of Oct1 expression inhibited LNCaP cell proliferation. Immunohistochemical analysis of Oct1expression in tumor specimens obtained from 102 patients with prostate cancer showed a positive correlation of Oct1immunoreactivity with a high Gleason score and AR immunoreactivity (p 5 0.0042 and p < 0.0001, respectively). Moreover,patients with high immunoreactivity of Oct1 showed a low cancer-specific survival rate, and those patients with highimmunoreactivities of both Oct1 and AR exhibited poorer cancer-specific prognosis. Multivariate hazard analysis revealed asignificant correlation between high Oct1 immunoreactivity and poor cancer-specific survival (p 5 0.012). These resultsdemonstrate that Oct1 can be a prognostic factor in prostate cancer as a coregulator of AR and may lead to the developmentof a new therapeutic intervention for prostate cancer.


2011 ◽  
Vol 38 (6) ◽  
pp. 506-518 ◽  
Author(s):  
Wei ZHANG ◽  
Ji-Yang ZHANG ◽  
Hui LIU ◽  
Han-Chang SUN ◽  
Chang-Ming XU ◽  
...  

2021 ◽  
Vol 14 (5) ◽  
pp. 385
Author(s):  
Leonardo L. Fuscaldi ◽  
Danielle V. Sobral ◽  
Ana Claudia R. Durante ◽  
Fernanda F. Mendonça ◽  
Ana Cláudia C. Miranda ◽  
...  

Prostate-specific membrane antigen (PSMA) is a glycoprotein present in the prostate, that is overexpressed in prostate cancer (PCa). Recently, PSMA-directed radiopharmaceuticals have been developed, allowing the pinpointing of tumors with the Positron Emission Tomography (PET) or Single Photon Emission Computed Tomography (SPECT) imaging techniques. The aim of the present work was to standardize and validate an automatic synthesis module-based radiolabeling protocol for [68Ga]Ga-PSMA-11, as well as to produce a radiopharmaceutical for PET imaging of PCa malignancies. [68Ga]Ga-PSMA-11 was evaluated to determine the radiochemical purity (RCP), stability in saline solution and serum, lipophilicity, affinity to serum proteins, binding and internalization to lymph node carcinoma of the prostate (LNCaP) cells, and ex vivo biodistribution in mice. The radiopharmaceutical was produced with an RCP of 99.06 ± 0.10%, which was assessed with reversed-phase high-performance liquid chromatography (RP-HPLC). The product was stable in saline solution for up to 4 h (RCP > 98%) and in serum for up to 1 h (RCP > 95%). The lipophilicity was determined as −3.80 ± 0.15, while the serum protein binding (SPB) was <17%. The percentages of binding to LNCaP cells were 4.07 ± 0.51% (30 min) and 4.56 ± 0.46% (60 min), while 19.22 ± 2.73% (30 min) and 16.85 ± 1.34% (60 min) of bound material was internalized. High accumulation of [68Ga]Ga-PSMA-11 was observed in the kidneys, spleen, and tumor, with a tumor-to-contralateral-muscle ratio of >8.5 and a tumor-to-blood ratio of >3.5. In conclusion, an automatic synthesis module-based radiolabeling protocol for [68Ga]Ga-PSMA-11 was standardized and the product was evaluated, thus verifying its characteristics for PET imaging of PCa tumors in a clinical environment.


2021 ◽  
Vol 20 ◽  
pp. 153473542199682
Author(s):  
Prathesha Pillai ◽  
Ginil Kumar Pooleri ◽  
Shantikumar V. Nair

Co-therapy with herbal extracts along with current clinical drugs is being increasingly recognized as a useful complementary treatment for cancer. The anti-cancer property of the phyto-derivative acetyl-11 keto β boswellic acid (AKBA) has been studied in many cancers, including prostate cancer. However, the whole extract of the gum resin Boswellia serrata (BS) and anti-androgen enzalutamide has not been explored in prostate cancer to date. We hypothesized that the BS extract containing 30% (AKBA) with enzalutamide acted synergistically in the early phase of cancer, especially in LNCaP cells, by inhibiting androgen receptor (AR) and by reducing cell proliferation, and further, that the extract would be superior to the action of the active ingredient AKBA when used alone or in combination with enzalutamide. To test our hypothesis, we treated LNCaP cells with BS extract or AKBA and enzalutamide both individually and in combination to analyze cell viability under different levels of dihydrotestosterone (DHT). The inhibition of androgen receptor (AR) followed by the expression of prostate-specific antigen (PSA) and the efflux mechanism of the cells were analyzed to determine the effect of the combination on the cellular mechanism. Cells derived from prostate cancer patients were also tested with the combination. Only 6 µM enzalutamide along with BS in the range of 4.1 µg/ml to 16.4 µg/ml gave the best synergistic results with nearly 50% cell killing even though standard enzalutamide doses were as high as 48 µM. Cell killing was most effective at intermediate DHT concentrations of approximately 1 nM, which corresponds to normal physiological serum levels of DHT. The Pgp expression level and the androgen receptor expression levels were reduced under the combination treatment; the former helping to minimize drug efflux and the latter by reducing the sensitivity to hormonal changes. Furthermore, the combination reduced the PSA level secreted by the cells. In contrast, AKBA could not achieve the needed synergism for adequate cell killing at equivalent concentrations. The combination of enzalutamide and BS extract containing 30% AKBA because of their synergistic interaction is an attractive therapeutic option for treating early stage (hormone-dependent) prostate cancer and is superior to the use of AKBA alone.


Sign in / Sign up

Export Citation Format

Share Document