Search results for "dna"

The role of SAXS and molecular simulations in 3D structure elucidation of a DNA aptamer against lung cancer

2021

Aptamers are short, single-stranded DNA or RNA oligonucleotide molecules that function as synthetic analogs of antibodies and bind to a target molecule with high specificity. Aptamer affinity entirely depends on its tertiary structure and charge distribution. Therefore, length and structure optimization are essential for increasing aptamer specificity and affinity. Here, we present a general optimization procedure for finding the most populated atomistic structures of DNA aptamers. Based on the existed aptamer LC-18 for lung adenocarcinoma, a new truncated LC-18 (LC-18t) aptamer LC-18t was developed. A three-dimensional (3D) shape of LC-18t was reported based on small-angle X-ray scattering…

Conductivity measurements of DNA TX tile and origami structures

2011

Tässä tutkielmassa on tutkittu kahden erilaisen itsejärjestyvän DNA-rakenteen sähkönjohtavuutta nanomittakaavassa. Ensimmäinen rakenteista on suorakaiteenmuotoinen kaksiulotteinen DNA-levy kooltaan noin 70×100 nm2 toisen ollessa selvästi kapeampi, noin 10×60 nm2. Suurin ero rakenteiden välillä on valmistusmenetelmä: isompi rakenne on valmistettu origamitekniikalla ja pienempi niin sanottua tiilimenetelmää käyttäen. Molekyylielektroniikan kannalta DNA:n sähkönjohtavuus on oleellinen asia, sillä DNA on itsejärjestäytymisominaisuuksiensa vuoksi osoittautunut hyvin lupaavaksi molekyyliksi: yksinkertaisten nanoskaalan laitteiden valmistus käyttäen DNA-pohjaisia menetelmiä on jo mahdollista. Työs…

DNA binding and biological activity of Cu(II) and Zn(II) complexes of a 2,5-diphenyl[1,3,4]oxadiazole macrocycle ligand.

2011

Pro-apoptotic activity of the phytochemical Indicaxanthin on colorectal carcinoma cells (Caco-2) and epigenetic CpG demethylation of the promoter and…

2012

Phytochemicals play prominent roles in human diet and nutrition as protective redo-active substances in prevention of several disorders and chronic diseases in humans. Today, their function as potent modulators of the mammalian epigenome-regulated gene expression is rapidly emerging. In the present study antiproliferative effects of Indicaxanthin (Ind) from the fruits of Opuntia ficus-indica (1), and potential influence on DNA methylation has been investigated on Caco-2 cells, a human cell line of colorectal carcinoma. Ind caused a clear dose- and time-dependent decrease of the cell proliferation (IC(50) 50 M) associated to apoptosis as demonstrated by phosphatidylserine externalization an…

Influence of aryl hydrocarbon- (Ah) receptor and genotoxins on DNA repair gene expression and cell survival of mouse hepatoma cells

2009

The aryl hydrocarbon receptor (AhR) mediates toxicity of a variety of environmental pollutants such as polycyclic aromatic hydrocarbons (PAHs) and dioxins. However, the underlying mechanisms and genetic programmes regulated by AhR to cause adverse effects but also to counteract poisoning are still poorly understood. Here we analysed the effects of two AhR ligands, benzo[a]pyrene (B[a]P), a DNA damaging tumour initiator and promotor and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a pure tumour promoter, on cell survival and on nucleotide excision repair (NER) gene expression. NER deals with so called "bulky" DNA adducts including those generated by enzymatically activated B[a]P. Therefore, t…

Cell-cycle control in cell-biomaterial interactions

2000

Current biocompatibility testing involves the demonstration of cell proliferation, which is usually interpreted as a sign of positive biocompatibility when the materials sustain cell proliferation. As the field of biomaterials research is rapidly moving toward tissue-engineered devices and hybrid organs, control of cell function has become a main topic. Cell function, which involves specific differentiation pathways, cannot be separated from cell-cycle control. The study of cell-cycle control is an important extension of routine proliferation assays and has extensive roots in developmental and tumor biology. We studied the expression of the tumour suppressor gene p53 and the proliferation-a…

p73 deficiency results in impaired self renewal and premature neuronal differentiation of mouse neural progenitors independently of p53

2010

10 p.-5 fig.

Heterogeneity within and between primary colorectal carcinomas and matched metastases as revealed by analysis of Ki-ras and p53 mutations

2004

Analysis of the genetic status of Ki-ras and p53 in primary colorectal carcinomas and matched colorectal liver metastasis from 30 patients reveals an overall heterogeneity both within and between the two tumoral tissues. Both genes were found mutated with a similar frequency in both tissues; however, identical mutations in primary tumor and matched metastasis were found less frequently in the case of the Ki-ras than the p53 gene. Only in three cases the same p53 and Ki-ras mutations found in the primary tumor were found also in the metastasis. In several metastatic specimens the DNA bearing a mutation detected also in the primary tumor appears significantly less abundant than the wild-type …

UV-B exposure causes DNA damage and changes in protein expression in northern pike (Esox lucius) posthatched embryos.

2012

The ongoing anthropogenically caused ozone depletion and climate change has increased the amount of biologically harmful UV-B radiation, which is detrimental to fish in embryonal stages. The effects of UV-B radiation on the levels and locations of DNA damage manifested as cyclobutane pyrimidine dimers (CPDs), heat shock protein 70 (HSP70) and p53 protein in newly hatched embryos of pike were examined. Pike larvae were exposed in the laboratory to current and enhanced doses of UV-B radiation. UV-B exposure caused the formation of CPDs in a fluence rate-dependent manner, and the CPDs were found deeper in the tissues with increasing fluence rates. UV-B radiation induced HSP70 in epidermis, and…

Digital control circuitry for the p53 dynamics in cancer cell and apoptosis

2010

Abstract Experimental work and theoretical models deduce a “digital” response of the p53 transcription factor when genomic integrity is damaged. The mutual influence of p53 and its antagonist, the Mdm2 oncogene, is closed in a feedback. This paper proposes an aerospace-based architecture for translating the p53/Mdm2/DNA damage network into a digital circuitry in which the optimal control theory is applied for obtaining the requested dynamic evolutions of some considered cell species for repairing a DNA damage. The purpose of this paper is to demonstrate the usefulness of such digital circuitry design to detect and predict the cell species dynamics for shedding light on their inner and mutua…