Knockdown of microRNA-135b in Mammary Carcinoma by Targeted Nanodiamonds: Potentials and Pitfalls of In Vivo Applications.

Nanodiamonds (ND) serve as RNA carriers with potential for in vivo application. ND coatings and their administration strategy significantly change their fate, toxicity, and effectivity within a multicellular system. Our goal was to develop multiple ND coating for effective RNA delivery in vivo. Our final complex (NDA135b) consisted of ND, polymer, antisense RNA, and transferrin. We aimed (i) to assess if a tumor-specific coating promotes NDA135b tumor accumulation and effective inhibition of oncogenic microRNA-135b and (ii) to outline off-targets and immune cell interactions. First, we tested NDA135b toxicity and effectivity in tumorospheres co-cultured with immune cells ex vivo. We found NDA135b to target tumor cells, but it binds also to granulocytes. Then, we followed with NDA135b intravenous and intratumoral applications in tumor-bearing animals in vivo. Application of NDA135b in vivo led to the effective knockdown of microRNA-135b in tumor tissue regardless administration. Only intravenous application resulted in NDA135b circulation in peripheral blood and urine and the decreased granularity of splenocytes. Our data show that localized intratumoral application of NDA135b represents a suitable and safe approach for in vivo application of nanodiamond-based constructs. Systemic intravenous application led to an interaction of NDA135b with bio-interface, and needs further examination regarding its safety.

Fluorescent Nanodiamonds are Efficient, Easy-to-Use Cyto-Compatible Vehicles for Monitored Delivery of Non-Coding Regulatory RNAs.

MicroRNAs are short molecules of RNA regulating most cellular processes via the mechanism of RNA interference. Their dysregulation leads to a disease burden, making them important therapeutic targets. For the successful development of a therapeutic device, the uptake of a functionalized carrier by live cells and the sufficient release of effector therapeutic molecules are limiting factors. Here for the first time, the inhibition of oncogenic microRNA-21 in CT-26 colon cancer cells is achieved, using an advanced nanosystem consisting of fluorescent nanodiamond and antisense RNA. Stable nanocomplexes efficiently deliver antisense RNA into cell cytoplasm, encouraging further study of microRNA-21 function in target cells. Engaging the fluorescent nanoparticle enables monitoring of transfection and release of the antisense RNA load into cell cytoplasm. Importantly, the internalized antisense RNA effectively destroys target microRNA-21 in CT-26 cancer cells. The absence of oncogenic microRNA-21 liberates tumor suppressor genes Pdcd4 and Timp3 from silencing, and results in a decrease of cell invasion and migration, and in the induction of apoptotic cell death. This study uses a nanodiamond-based imaging and delivery system, and shows that the multidimensional performance of the presented device makes nanodiamond-based complexes promising therapeutic devices.

Interaction of colon cancer cells with glycoconjugates triggers complex changes in gene expression, glucose transporters and cell invasion.

Glycan metabolism balance is critical for cell prosperity, and macromolecule glycosylation is essential for cell communication, signaling and survival. Thus, glycotherapy may be a potential cancer treatment. The aim of the present study was to determine whether combined synthetic glycoconjugates (GCs) induce changes in gene expression that alter the survival of colon cancer cells. The current study evaluated the effect of the GCs N­acetyl­D­glucosamine modified polyamidoamine dendrimer and calix[4]arene scaffold on cancer cell proliferation, apoptosis, invasion and sensitivity to immune cell­mediated killing. Using reverse transcription­quantitative polymerase chain reaction, the expression of genes involved in the aforementioned processes was measured. It was determined that GCs reduce the expression of the glucosaminyltransferases Mgat3 and Mgat5 responsible for surface glycosylation and employed components of the Wnt signaling pathway Wnt2B and Wnt9B. In addition, the calix[4]arene­based GC reduced cell colony formation; this was accompanied by the downregulation of the metalloproteinase Mmp3. By contrast, the dendrimer­based GC affected the expression of the glucose transporter components Sglt1 and Egfr1. Therefore, to the best of our knowledge, the present study is the first to reveal that N­acetyl­D­glucosamine­dendrimer/calix[4]arene GCs alter mRNA expression in a comprehensive way, resulting in the reduced malignant phenotype of the colon cancer cell line HT­29.

Slower postnatal motor development in infants of mothers with latent toxoplasmosis during the first 18 months of life.

Toxoplasmosis, a zoonosis caused by a protozoan, Toxoplasma gondii, is probably the most widespread human parasitosis in developed countries. Pregnant women with latent toxoplasmosis have seemingly younger fetuses especially in the 16th week of gestation, which suggests that fetuses of Toxoplasma-infected mothers have slower rates of development in the first trimester of pregnancy. In the present retrospective cohort study, we analyzed data on postnatal motor development of infants from 331 questionnaire respondents including 53 Toxoplasma-infected mothers to search for signs of early postnatal development disorders. During the first year of life, a slower postnatal motor development was observed in infants of mothers with latent toxoplasmosis. These infants significantly later developed the ability to control the head position (p=0.039), to roll from supine to prone position (p=0.022) and were slightly later to begin crawling (p=0.059). Our results are compatible with the hypothesis that the difference in the rates of prenatal and early postnatal development between children of Toxoplasma-negative and Toxoplasma-positive mothers might be caused by a decreased stringency of embryo quality control in partly immunosuppressed Toxoplasma-positive mothers resulting in a higher proportion of infants with genetic or developmental disorders in offspring. However, because of relatively low return rate of questionnaires and an associated risk of a sieve effect, our results should be considered as preliminary and performing a large scale prospective study in the future is critically needed.

Pattern of money allocation in experimental games supports the stress hypothesis of gender differences in Toxoplasma gondii-induced behavioural changes.

Latent toxoplasmosis has been previously found to cause behavioural and personality changes in humans, which are specific for each gender. Here we tested the stress hypothesis of these gender differences based on the assumption that latent toxoplasmosis causes long-term subliminal stress. In line with this hypothesis, the gender difference will appear specifically in situations with interpersonal context because in contrast to the typical individualistic coping style of men, women have a tendency to express elevated prosocial behaviour under stress. Altogether 295 biology students (29/191 females and 27/104 males infected by T. gondii) played a modified version of the Dictator Game and the Trust Game. As predicted, a gender difference in the effect of latent toxoplasmosis was found for the measure of reciprocal altruism in the Trust Game (p = 0.016), but both genders appeared less generous when infected in the Dictator Game modified to minimize social connotation (p = 0.048).