No abstract

Magnetic silica nanoparticles show great promise for drug delivery. The major advantages correspond to their magnetic nature and ease of biofunctionalization, which favors their ability to interact with cells and tissues. We have prepared magnetic silica nanoparticles with DNA fragments attached on their previously polyelectrolyte-primed surface. The remarkable feature of these materials is the compromise between the positive charges of the polyelectrolytes and the negative charges of the DNA. This dual-agent formulation dramatically changes the overall cytotoxicity and chemical degradation of the nanoparticles, revealing the key role that surface functionalization plays in regulating the mechanisms involved.

We studied the specific changes of the secreted protein clusterin and its cytoplasmic precursor regarding colorectal tumorigenesis, using in vitro differentiation of Caco-2 cells. In tumor-like stage, we observed an overexpression of both precursor and secreted clusterin, corroborated in the cell line SW-480. Noticeably, SW-620 cells (from a tumoral node, thus with metastatic capacity) did not show overexpression of either precursor or secreted clusterin, suggesting a downregulation related to local metastasis. We further investigated clusterin in serum, finding a significant increase in colorectal cancer patients, with 81% sensitivity, 79% specificity, and an area under the ROC curve of 0.85.

No abstract

Colorectal cancer is still a major health burden worldwide, and its diagnosis has not improved in recent years due to a lack of appropriate diagnostic serum markers. Aiming to find new diagnostic proteins, we applied the proteomic DIGE technology to analyze changes in the secretome before/after differentiation of the colon adenocarcinoma Caco-2 cell line, an accepted in vitro model to study colorectal tumorigenesis. When the secretomes from undifferentiated (tumor-like) and differentiated cells (resembling healthy enterocytes) were compared, we found 96 spots differentially expressed. After MS/MS analysis, 22 spots corresponding to 15 different proteins were identified. Principal component analysis demonstrated these 22 spots could serve as a discriminatory panel between the tumor-like and normal-like cells. Among the identified proteins, the translationally-controlled tumor protein (TCTP), the transforming growth factor-beta-induced protein ig-h3 (TGFβIp), and the Niemann-Pick disease type C2 protein (NPC2) are interesting candidates for future studies focused on their utility as serum biomarkers of colorectal cancer.