METCAM Is a Potential Biomarker for Predicting the Malignant Propensity of and as a Therapeutic Target for Prostate Cancer.

Prostate cancer is the second leading cause of cancer-related death worldwide. This is because it is still unknown why indolent prostate cancer becomes an aggressive one, though many risk factors for this type of cancer have been suggested. Currently, many diagnostic markers have been suggested for predicting malignant prostatic carcinoma cancer; however, only a few, such as PSA (prostate-specific antigen), Prostate Health Index (PHI), and PCA3, have been approved by the FDA. However, each biomarker has its merits as well as shortcomings. The serum PSA test is incapable of differentiating prostate cancer from BPH and also has an about 25% false-positive prediction rate for the malignant status of cancer. The PHI test has the potential to replace the PSA test for the discrimination of BPH from prostate cancer and for the prediction of high-grade cancer avoiding unnecessary biopsies; however, the free form of PSA is unstable and expensive. PCA3 is not associated with locally advanced disease and is limited in terms of its prediction of aggressive cancer. Currently, several urine biomarkers have shown high potential in terms of being used to replace circulating biomarkers, which require a more invasive method of sample collection, such as via serum. Currently, the combined multiple tumor biomarkers may turn out to be a major trend in the diagnosis and assessment of the treatment effectiveness of prostate cancer. Thus, there is still a need to search for more novel biomarkers to develop a perfect cocktail, which consists of multiple biomarkers, in order to predict malignant prostate cancer and follow the efficacy of the treatment. We have discovered that METCAM, a cell adhesion molecule in the Ig-like superfamily, has great potential regarding its use as a biomarker for differentiating prostate cancer from BPH, predicting the malignant propensity of prostate cancer at the early premalignant stage, and differentiating indolent prostate cancers from aggressive cancers. Since METCAM has also been shown to be able to initiate the spread of prostate cancer cell lines to multiple organs, we suggest that it may be used as a therapeutic target for the clinical treatment of patients with malignant prostate cancer.

Validating METCAM/MUC18 as a Novel Biomarker to Predict the Malignant Potential of Prostate Cancer at an Early Stage by Using a Modified Gold Nanoparticles-Based Lateral Flow Immunoassay.

(1) Background: To further validate METCAM/MUC18 as a diagnostic biomarker for prostate cancer, a modified Lateral Flow Immune Assay (LFIA) with increased sensitivity and specificity was designed by taking advantage of the extremely high affinity between biotin and streptavidin and used. (2) Methods: The combination of a commercial biotinylated rabbit antibody (EPP11278), or the home-made biotinylated chicken antibody, and the nano-gold conjugated home-made chicken antibody or a commercial rabbit antibody (EPP11278), had the higher sensitivity and specificity in this modified LFIA to establish calibration curves from the two recombinant METCAM/MUC18 proteins and were used for determining METCAM/MUC18 concentrations in serum specimens from normal individuals, benign prostatic hyperplasia (BPH) patients, prostatic intraepithelial neoplasia (PIN) patients, prostate cancer patients with various Gleason scores, and treated patients. (3) Results: Data obtained by this modified LFIA were statistically better than traditional LFIA and prostate-specific antigen (PSA) test. Interestingly, serum METCAM/MUC18 concentrations were higher in pre-malignant PIN patients than prostate cancer patients and both were higher than normal individuals, BPH patients, and treated patients. Serum METCAM/MUC18 concentrations were directly proportional to most serum PSA. (4) Conclusions: Elevated serum METCAM/MUC18 concentrations may be used for predicting the malignant potential of prostate cancer at an early premalignant (PIN) stage, which is not achievable by the current PSA test.

METCAM/MUC18 is a new early diagnostic biomarker for the malignant potential of prostate cancer: Validation with Western blot method, enzyme-linked immunosorbent assay and lateral flow immunoassay.

BACKGROUND: METCAM/MUC18 expression was increased with the malignant progression of prostate cancer and also a bona fide metastatic gene, capable of initiating and driving the metastasis of a non-metastatic human prostate cancer cell line to multiple organs. OBJECTIVE: We explored if METCAM/MUC18 was detectable in human serum and a novel biomarker to predict malignant propensity of prostate cancer. MATERIALS AND METHODS: Two antibodies were identified by Western blot analysis having the highest sensitivity and specificity to establish calibration curves from the recombinant METCAM/MUC18 proteins. They were used in ELISA and LFIA to determine the METCAM/MUC18 concentrations in serum samples from 8 normal individuals, 4 BPH patients, 1 with PIN, 6 with high-grade prostate cancer, and 2 treated cancer patients. RESULTS: Serum METCAM/MUC18 concentrations were statistically significantly higher in the patients with PIN and prostate cancer than those with BPH, the treated patients and normal individuals. The LFIA results were statistically better than ELISA and Western blot methods. Serum METCAM/MUC18 concentrations were in direct proportional to most of serum PSA concentrations.

Electrophoresis-enhanced detection of deoxyribonucleic acids on a membrane-based lateral flow strip using avian influenza H5 genetic sequence as the model.

This study reports a simple strategy to detect a deoxyribonucleic acid (DNA) on a membrane-based lateral flow (MBLF) strip without tedious gel preparation, gel electrophoresis, and EtBr-staining processes. The method also enhances the detection signal of the genetic sample. A direct electric field was applied over two ends of the MBLF strips to induce an electrophoresis of DNAs through the strips. The signal enhancement was demonstrated by the detection of the H5 subtype of avian influenza virus (H5 AIV). This approach showed an excellent selectivity of H5 AIV from other two control species, Arabidopsis thaliana and human PSMA5. It also showed an effective signal repeatability and sensitivity over a series of analyte concentrations. Its detection limit could be enhanced, from 40 ng to 0.1 ng by applying 12 V. The nano-gold particles for the color development were labeled on the capture antibody, and UV-VIS and TEM were used to check if the labeling was successful. This detection strategy could be further developed to apply on the detection of drug-allergic genes at clinics or detection of infectious substances at incident sites by a simple manipulation with an aid of a mini-PCR machine and auxiliary kits.

Three-dimensional arrayed amino aerogel biochips for molecular recognition of antigens.

The three-dimensional (3D) biochips prepared in this study are composed of a glass microscopy slide arrayed with amino aerogel dots. The amino aerogel was produced using the sol-gel process, with an ionic liquid as the template followed by a solvent extraction to remove the template and build a three-dimensional mesoporous structure. The FTIR spectrum verified that the major template was removed and the (29)Si solid-state NMR spectra recognized the cross-linkages in the SiO(2) network structure. SEM images measured the particles at around 100 nm. After grinding, the BET analysis confirmed that the nano-size amino aerogel powders had exhibited specific surface area of 188 m(2)/g, pore volume of 0.83 cm(3)/g, and average pore size of 16.2 nm. The as-prepared amino aerogel surface contained amino functional groups capable of performing a sandwich immunoassay. The primary antibody was immobilized on the internal surface of the arrayed amino aerogel to capture its affinity antigen. On the top of the captured antigen, the report antibody was read its labeling fluorescent dye. In comparison to the corresponding two-dimensional (2D) biochip, the 3D amino aerogel biochips were observed to amplify signal intensities more effectively due to their remarkable capturing capability.

Effect of co-axially hybridized gene targets on hybridization efficiency of microarrayed DNA probes.

The effect of relative size of two co-axially hybridized gene targets on the hybridization efficiency was studied for two DNA probe configurations and various probe concentrations. Each of two sets of microarrayed probes contained a pair of DNA probes and a pair of their complementary samples labeled with two distinct fluorescent dyes. The sequence of each probe is especially designed so that two targets are simultaneously complementary to two adjacent sections of the probe. The molecular steric effect on the hybridization efficiency is investigated by comparing the dye signals between configurations of one-target and two-target hybridization scenarios. The results show that a low probe concentration gives better hybridization efficiency and the first-hybridization conducted by a shorter-size DNA target improves the hybridization efficiency of the second target coupling onto the same probe.

A novel three-dimensional aerogel biochip for molecular recognition of nucleotide acids.

Mesoporous aerogel was produced under regular atmospheric conditions using the sol-gel polymerization of tetraethyl orthosilicate with an ionic liquid as both solvent and active agent. This was then used to build a three-dimensional structure to recognize nucleotide acids. Fourier transformation infrared spectroscopy, scanning electron microscopy, (29)Si solid-state nuclear magnetic resonance, and Brunauer-Emmett-Teller instruments were used to characterize this 3D aerogel, demonstrating that it had high porosity and large internal networking surface area that could capture nucleotide acids. The functionality of molecular recognition on nucleotide acids was demonstrated by immobilizing an oligonucleotide to probe its DNA target and confirming the tagged fluorescent signals by confocal laser scanning microscopy. The results indicated that the as-prepared 3D bioaerogel was capable of providing a very large surface area to capture and recognize human gene ATP5O.

Patch-distribution effect on diffusion-limited process in dilute suspension of partially active spheres.

The normalized overall rate constant, kp/kf for diffusion-limited processes in a dilute suspension of spheres, partially covered with active patches of varying distribution states, is studied with sped-up Brownian dynamic simulations. A dimensionless separation index Is is defined to quantify the characteristics of patch distribution on the sphere surfaces, with values of 0 and 1 corresponding to the states of the most compact and loosest patch distributions, respectively. Remarkably, the normalized overall rate constant is found to strongly correlate with the dimensionless separation index at fixed patch coverage fcover exhibiting a positive, linear relationship. In addition, the slope of the kp/kf vs Is line, a measure of sensitivity of kp/kf to variation in the separation state of the distributed patches, is found to depend on patch coverage and patch size. This sensitivity exhibits a maximum value with respect to an increase in patch coverage, and the magnitude of the maximum sensitivity decreases with increasing patch size. The patch coverage, at which the maximum sensitivity occurs, increases with increasing patch size.