Gene expression profiles have demonstrated that miR-21 expression is altered in almost all types of cancers and it has been classified as an oncogenic microRNA. Persistent HPV infection is the main etiologic agent in cervical cancer and induces genetic instability, including disruption of microRNA gene expression. In the present study, we analyzed the underlying mechanism of how AP-1 transcription factor can active miR-21 gene expression in cervical cancer cells. To identify that c-Fos and c-Jun regulate the expression of miR-21 we performed RT-qPCR and western blot assays. We analyzed the interaction of AP-1 with miR-21 promoter by EMSA and ChIP assays and determined the mechanism of its regulation by reporter construct plasmids. We identified the nuclear translocation of c-Fos and c-Jun by immunofluorescence microscopy assays. We demonstrated that c-Fos and c-Jun proteins are expressed and regulate the expression of miR-21 in cervical cancer cells. DNA sequence analysis revealed the presence of AP-1 DNA-binding sites in the human miR-21 promoter region. EMSA analyses confirmed the interactions of the miR-21 upstream transcription factor AP-1. ChIP assays further showed the binding of c-Fos to AP-1 sequences from the miR-21 core promoter in vivo. Functional analysis of AP-1 sequences of miR-21 in reporter plasmids demonstrated that these sequences increase the miR-21 promoter activation. Our findings suggest a physical interaction and functional cooperation between AP-1 transcription factor in the miR-21 promoter and may explain the effect of AP-1 on miR-21 gene expression in cervical cancer cells.

Melanin is an insoluble, amorphous polymer that forms planar sheets that aggregate naturally to create colloidal particles with several biological functions. Based on this, here, a preformed recombinant melanin (PRM) was utilized as the polymeric raw material to generate recombinant melanin nanoparticles (RMNPs). These nanoparticles were prepared using bottom-up (nanocrystallization—NC, and double emulsion–solvent evaporation—DE) and top-down (high-pressure homogenization—HP) manufacturing approaches. The particle size, Z-potential, identity, stability, morphology, and solid-state properties were evaluated. RMNP biocompatibility was determined in human embryogenic kidney (HEK293) and human epidermal keratinocyte (HEKn) cell lines. RMNPs prepared by NC reached a particle size of 245.9 ± 31.5 nm and a Z-potential of −20.2 ± 1.56 mV; 253.1 ± 30.6 nm and −39.2 ± 0.56 mV compared to that obtained by DE, as well as RMNPs of 302.2 ± 69.9 nm and −38.6 ± 2.25 mV using HP. Spherical and solid nanostructures in the bottom-up approaches were observed; however, they were an irregular shape with a wide size distribution when the HP method was applied. Infrared (IR) spectra showed no changes in the chemical structure of the melanin after the manufacturing process but did exhibit an amorphous crystal rearrangement according to calorimetric and PXRD analysis. All RMNPs presented long stability in an aqueous suspension and resistance to being sterilized by wet steam and ultraviolet (UV) radiation. Finally, cytotoxicity assays showed that RMNPs are safe up to 100 μg/mL. These findings open new possibilities for obtaining melanin nanoparticles with potential applications in drug delivery, tissue engineering, diagnosis, and sun protection, among others.

In recent years, metallodrugs have been playing an important role, showing to be more efficient in the treatment of several diseases, such as cancer. Indeed, it is important to synthesize novel molecules to be used as more effective agents against cancer. In the present paper, the synthesis of two new molecules belonging to Casiopeínas^® is reported. These compounds present a β²-aminoacidate derivative as the secondary ligand. The novel metal complexes were characterized by high-resolution mass spectrometry, FT-IR, UV-Vis, EPR, effective magnetic moment and cyclic voltammetry measurements, and single crystal X-ray diffraction analysis. Furthermore, these compounds were evaluated in vitro against the cancer lines MCF-7 (breast cancer) and A549 (lung cancer).

Recombinant proteins represent one of the greatest achievements of modern pharmaceutical biotechnology, as they are increasingly used across nearly all branches of medicine to treat a wide range of conditions. In response to this demand, various cell engineering approaches have been developed to improve their expression. Some of these approaches involve the use of genetic elements that prevent the silencing of the gene of interest, as well as the generation of resistant cell lines to inhibit or avoid programmed cell death (PCD). This research focuses on analyzing the effects of overexpression of UCOE elements and the HSP27 protein, both individually and together, on the production of human rIFN γ in HEK293 cells. Our results show that 4‐Kb UCOE elements have no effect on protein production in HEK293 cells, while overexpression of HSP27 prolongs the stationary phase during growth kinetics. The Qp of rIFN γ is 96‐fold higher in clones containing the HSP27/UCOE combination compared to the clone containing only UCOE elements or to the control HEK293 cells. These results correlate with the MCP analyses, which showed that overexpression of HSP27 decreased the expression of Bax, caspase 3, cytochrome C, Beclin, and LC3II mRNA. Finally, this study suggests the potential utility of a cell engineering approach based on the overexpression of the human HSP27 protein for enhancing the production of recombinant viruses and proteins in HEK293 cells.

HEK293 cells are the common system to produce adenoviral vectors for vectorized vaccines and gene therapy products. Therefore, the improvement of this type of cell culture is highly relevant nowadays. Furthermore, the high aspect ratio vessel (HARV) bioreactor provides a simulated microgravity condition (SMGC) which allows the establishment of in vitro models of mammalian cells. The present work is aimed at showing the characterization of HEK293 cell cultures in serum‐free medium under SMGC and to identify a set of adaptable time differential equations from experimental data through a nonparametric mathematical modeling using differential neural networks (DNN). Results showed that the HARV bioreactor enables to obtain a gravity percentage equal to 〖%g〗_maximum = −0.053% (where minus sign implies against the gravity direction). In addition, the characterization of HEK293 culture under SMGC revealed that such condition favored the production of infective viral particles as well as the uptake of basic nutrients such as glucose and glutamine, but the cell concentration was not significantly affected. As shown, these results contribute to improve the adenoviral vector production, and the DNN analysis is useful to model the kinetic changes and to build the foundations for control strategies and optimization of adenoviral production in further studies.

Recombinant proteins represent one of the greatest achievements of modern pharmaceutical biotechnology, as they are increasingly used in almost all branches of medicine to treat a wide range of conditions. For responding to this demand, different cell engineering approaches have been developed to improve their expression. Some of them include the use of genetic elements that have the ability to prevent the silencing of the gene of interest and the generation of resistant cell lines to inhibit or avoid the Programmed Cell Death (PCD). This research focuses on the analysis of the effect of overexpression of UCOE elements and the HSP27 protein individually and together on the production of human rIFNγ in HEK293 cells. Our results show that UCOE elements of 4 kbp do not have any effect on protein production in HEK293 cells while overexpression of HSP27 prolongs the stationary phase during growth kinetics. It was also observed that the Qp of rIFNγ is 96-fold higher in clones containing the HSP27/UCOE combination compared to the clone containing only UCOE elements nor to the control cell HEK293. These results correlate with the MCP analyses, as HSP27 overexpression was observed to decrease the expression of bax, caspase 3 and cytochrome C messengers, beclin and LC3II. This study proposes the utility of a cell engineering approach based on the overexpression of the human HSP27 protein to develop the production of recombinant viruses and proteins in HEK293 cells.