Nanohydroxyapatite/Graphene Nanoribbons Nanocomposites Induce in Vitro Osteogenesis and Promote in Vivo Bone Neoformation.

Nanomaterials based on graphene oxide nanoribbons (GNR) and nanohydroxyapatite (nHAp) serve as attractive materials for bone tissue engineering. Herein, we evaluated the potential of nHAp/GNR toward in vitro analysis of specific genes related to osteogenesis and in vivo bone regeneration using animal model. Three different concentrations of nHAp/GNR composites were analyzed in vitro using a cytotoxicity assay, and osteogenic potential was determined by ALP, OPN, OCN, COL1, and RUNX2 genes and alkaline phosphatase assays. In vivo bone neoformation using a well-established in vivo rat tibia defect model was used to confirm the efficiency of the optimized composite. The scaffolds were nontoxic, and the osteogenesis process was dose-dependent (at 200 µg mL-1 of nHAp/GNR) compared to controls. The in vivo results showed higher bone neoformation after 15 days of nHAp/GNR implantation compared to all groups. After 21 days, both nHAp/GNR composites showed better lamellar bone formation compared to control. We attributed this enhanced bone neoformation to the high bioactivity and surface area presented by nHAp/GNR composites, which was systematically evaluated in previous studies. These new in vivo results suggest that nHAp/GNR composites can be exploited for a range of strategies for the improved development of novel dental and orthopedic bone grafts to accelerate bone regeneration.

Identification of novel biomarkers associated with poor patient outcomes in invasive breast carcinoma.

Breast carcinoma (BC) corresponds to 23 % of all cancers in women, with 1.38 million new cases and 460,000 deaths worldwide annually. Despite the significant advances in the identification of molecular markers and different modalities of treatment for primary BC, the ability to predict its metastatic behavior is still limited. The purpose of this study was to identify novel molecular markers associated with distinct clinical outcomes in a Brazilian cohort of BC patients. We generated global gene expression profiles using tumor samples from 24 patients with invasive ductal BC who were followed for at least 5 years, including a group of 15 patients with favorable outcomes and another with nine patients who developed metastasis. We identified a set of 58 differentially expressed genes (p ≤ 0.01) between the two groups. The prognostic value of this metastasis signature was corroborated by its ability to stratify independent BC patient datasets according to disease-free survival and overall survival. The upregulation of B3GNT7, PPM1D, TNKS2, PHB, and GTSE1 in patients with poor outcomes was confirmed by quantitative reverse transcription polymerase chain reaction (RT-qPCR) in an independent sample of patients with BC (47 with good outcomes and eight that presented metastasis). The expression of BCL2-associated agonist of cell death (BAD) protein was determined in 1276 BC tissue samples by immunohistochemistry and was consistent with the reduced BAD mRNA expression levels in metastatic cases, as observed in the oligoarray data. These findings point to novel prognostic markers that can distinguish breast carcinomas with metastatic potential from those with favorable outcomes.

Molecular analysis of apoptosis pathway after photodynamic therapy in breast cancer: Animal model study.

BACKGROUND: Molecular investigation of breast tumors has permitted better understanding about interaction of genes and pathways involved in tumor progression. OBJECTIVE: The aim of this study was to evaluate the association between genes belonging to the pathway of apoptosis with tumor response to photodynamic therapy. STUDY DESIGN/MATERIALS AND METHODS: The mammary tumors were induced in twenty-four Spraguey-Dawley female rats by oral gavage of 7,12-dimethylbenz(a)anthracene (8mg/Kg body weight). Animals were divided into three groups: G1 (normal tissue), G2 (tumors without treatment), G3 (animals euthanized 48h after treatment). The photosensitizer used was a chlorin, 5,15-bis-(2-bromo-5-hydroxyphenyl) chlorin in the dose of 8mg/kg for each animal. Light source of diode laser at a wavelength of 660nm, fluence rate of 100mW/cm, and light dose of 100J/cm was delivery to lesions for treatment. A sample from each animal was investigated by quantitative real time PCR using Rat Apoptosis RT(2) Profiler™ PCR Array platform. RESULTS: Pro-apoptotic BAK1, CARD6, CASP8, CIDEA, CIDEB, DAPK1, TNF, TNFRSF10B, FASLG, LOC687813, and TP73 genes showed increased expression, and CD40 anti-apoptotic gene showed decreased expression in the group who underwent PDT (G3) in relation to G2. CONCLUSION: The results indicated that these genes are involved more directly with cellular apoptosis induced by PDT using the Chlorin photosensitizer.

Ribosomal DNA nanoprobes studied by Fourier transform infrared spectroscopy.

Paracoccidioides brasiliensis (P. brasiliensis) is a thermo-dimorphic fungus that causes paracoccidioidomycosis. Brazil epidemiological data shows that endemic areas are the subtropical regions, especially where agricultural activities predominate such as the Southeast, South, and Midwest. There are several tests to diagnose paracoccidioidomycosis, but they have many limitations such as low sensitivity, high cost, and a cross-reacting problem. In this work, gold nanoprobes were used to identify P. brasiliensis as an alternative diagnostic technique, which is easier to apply, costs less, and has great potential for application. The specific Ribosomal sequence of P. brasiliensis DNA was amplified and used to design the nanoprobes using a thiol-modified oligonucleotide. The results of positive and negative tests were done by UV-visible and Fourier Transform Infrared (FT-IR) measurements. The deconvolution of FT-IR sample spectra showed differences in the vibrational modes from the hydrogen bridge NHN and NHO bands that form the double helix DNA for samples matching the DNA sequence of nanoprobes that could be used to classify the samples.

Independent clonal origin of multiple uterine leiomyomas that was determined by X chromosome inactivation and microsatellite analysis.

OBJECTIVE: In an attempt to clarify the clonality and genetic relationships that are involved in the tumorigenesis of uterine leiomyomas, we used a total of 43 multiple leiomyomas from 14 patients and analyzed the allelic status with 15 microsatellite markers and X chromosome inactivation analysis. STUDY DESIGN: We have used a set of 15 microsatellite polymorphism markers mapped on 3q, 7p, 11, and 15q by automated analysis. The X chromosome inactivation was evaluated by the methylation status of the X-linked androgen receptor gene. RESULTS: Loss of heterozygosity analysis showed a different pattern in 7 of the 8 cases with allelic loss for at least 1 of 15 microsatellite markers that were analyzed. A similar loss of heterozygosity findings at 7p22-15 was detected in 3 samples from the same patient. X chromosome inactivation analysis demonstrated the same inactivated allele in all tumors of the 9 of 12 informative patients; different inactivation patterns were observed in 3 cases. CONCLUSION: Our data support the concept that uterine leiomyomas are derived from a single cell but are generated independently in the uterus. Loss of heterozygosity findings at 7p22-15 are consistent with previous data that suggested the relevance of chromosomal aberrations at 7p that were involved in individual uterine leiomyomas.

Large-scale transcriptome analyses reveal new genetic marker candidates of head, neck, and thyroid cancer.

A detailed genome mapping analysis of 213,636 expressed sequence tags (EST) derived from nontumor and tumor tissues of the oral cavity, larynx, pharynx, and thyroid was done. Transcripts matching known human genes were identified; potential new splice variants were flagged and subjected to manual curation, pointing to 788 putatively new alternative splicing isoforms, the majority (75%) being insertion events. A subset of 34 new splicing isoforms (5% of 788 events) was selected and 23 (68%) were confirmed by reverse transcription-PCR and DNA sequencing. Putative new genes were revealed, including six transcripts mapped to well-studied chromosomes such as 22, as well as transcripts that mapped to 253 intergenic regions. In addition, 2,251 noncoding intronic RNAs, eventually involved in transcriptional regulation, were found. A set of 250 candidate markers for loss of heterozygosis or gene amplification was selected by identifying transcripts that mapped to genomic regions previously known to be frequently amplified or deleted in head, neck, and thyroid tumors. Three of these markers were evaluated by quantitative reverse transcription-PCR in an independent set of individual samples. Along with detailed clinical data about tumor origin, the information reported here is now publicly available on a dedicated Web site as a resource for further biological investigation. This first in silico reconstruction of the head, neck, and thyroid transcriptomes points to a wealth of new candidate markers that can be used for future studies on the molecular basis of these tumors. Similar analysis is warranted for a number of other tumors for which large EST data sets are available.