Assessing Specificity of Anticancer Drugs In Vitro

New insights into the role of ribonuclease P protein subunit p30 from tumor to internal reference

Ribonuclease P protein subunit p30 (RPP30) is a highly conserved housekeeping gene that exists in many species and tissues throughout the three life kingdoms (archaea, bacteria, and eukaryotes). RPP30 is closely related to a few types of tumors in human diseases but has a very stable transcription level in most cases. Based on this feature, increasing number of studies have used RPP30 as an internal reference gene. Here, the structure and basic functions of RPP30 are summarized and the likely relationship between RPP30 and various diseases in plants and human is outlined. Finally, the current application of RPP30 as an internal reference gene and its advantages over traditional internal reference genes are reviewed. RPP30 characteristics suggest that it has a good prospect of being selected as an internal reference; more work is needed to develop this research avenue.

Co-Functionalization of Gold Nanoparticles with C7H2 and HuAL1 Peptides: Enhanced Antimicrobial and Antitumoral Activities

The functionalization of nanoparticles with therapeutic peptides has been pointed out as a promising strategy to improve the applications of these molecules in the field of health sciences. Peptides are highly bioactive but face several limitations such as low bioavailability due to the difficulty of overcoming the physiological barriers in the body and their degradation by enzymes. In this work, gold nanoparticles (AuNPs) were co-functionalized with two therapeutic peptides simultaneously. The peptides from the complementary determining region of monoclonal antibodies, composed of the amino acid sequences YISCYNGATSYNQKFK (C7H2) and RASQSVSSYLA (HuAL1) were chosen for having exhibited antitumor and antimicrobial activity before. The peptides-conjugated AuNPs were characterized regarding size, morphology, and metal concentration by using TEM, dynamic light scattering, and ICP-OES techniques. Then, peptides-conjugated AuNPs were evaluated regarding the antimicrobial activity against E. coli, P. aeruginosa, and C. albicans. The antitumoral activity was evaluated in vitro by cell viability assays with metastatic melanoma cell line (B16F10-Nex2) and the cytotoxicity was evaluated against human foreskin fibroblast (Hs68) cell line. Finally, in vivo assays were performed by using a syngeneic animal model of metastatic melanoma. Our findings have highlighted the potential application of the dual-peptide AuNPs in order to enhance the antitumor and antimicrobial activity of peptides.

Two simple and inexpensive methods for preparing DNA suitable for digital PCR from a small number of cells in 96-well plates

Background

Although DNA of high quality can be easily prepared from cultured cells with commercially available kits, many studies involve a large number of samples which increases the cost drastically. We optimized two simple and inexpensive methods for preparing DNA suitable for digital PCR from a small number of cells directly from wells of 96‐well plates.

Methods

Cells (number: 10³‐10⁴) were lysed with a Direct PCR^® lysis buffer or a 10% Chelex100® solution. The lysates were further purified and concentrated by means of DNA precipitation with a blue‐colored glycogen as a carrier. PCR and digital PCR were used to evaluate the efficiency of the two methods.

Results

For 1000 cells from one primary culture and two tumor cell lines, DNA was reproducible and obtained with recovery rate (obtained/expected amount of DNA) in the range of 50%‐90% as measured by the fluorometer dyes instrument Qubit. Using 8 out of a total of 10 µL DNA solution for 1000 cells, both conventional PCR and digital PCR were successful. For digital PCR, more than 1600 positive droplets were obtained for DNA from 1000 cells using the Direct PCR^® method, corresponding to a yield efficiency of approximately 80%. Further reducing the number of cells down to 100 would be possible with 160 positive droplets expected. Both reagents are inexpensive (0.08€/sample).

Conclusions

Two methods are efficient, especially the Direct PCR^® reagent‐based method provides a simple and inexpensive method for preparing DNA suitable for digital PCR from small number of cells.