Methylation analysis of MIR200 family in Mexican patients with colorectal cancer

The present study aimed to analyze the methylation pattern of the MIR200 family in the colorectal tissues and peripheral blood of colorectal cancer (CRC) patients. Previous informed consent, 102 samples of colorectal tissues (tumor and adjacent normal tissues) and 40 peripheral blood samples were collected from CRC patients. Additionally, we included a reference group of 40 blood samples. DNA extraction was done for colorectal tissues and peripheral blood. For methylation-specific PCR, we used bisulfite-treated DNA and controls for methylated and unmethylated DNA were included to each assay. PCR fragments were separated by 6% polyacrylamide gel electrophoresis. Methylation-positive and methylation-negative results were confirmed by bisulfite genomic sequencing technique. We analyzed 102 colorectal tissues and 40 blood samples from 51 CRC patients. MIR200B/MIR200A/MIR429 methylation analysis discloses no differences among tissues (p>0.05). However, MIR200C/MIR141 methylation showed differences between colorectal tissues and peripheral blood of CRC patients (p<0.0001) and mainly methylated alleles were observed in peripheral blood. These findings suggest a tissue-specific methylation pattern for the MIR200C/MIR141 promoter.

Epidermal growth factor receptor expression in gastric tumors and its relationship with the germline polymorphisms - 216 G>T, -191 C>A, (CA) n IVS1, and R521K

BACKGROUND

Gastric cancer (GC) is the third worldwide leading cause of cancer-related death affecting both sexes. The aberrant expression of epidermal growth factor receptor (EGFR) gene has been detected in many human epithelial malignancies and linked to advanced disease, more aggressive phenotype, and poor prognosis.

AIMS

To analyze the relation that the expression of EGFR in gastric tumors holds with pathological characteristics and with the germline polymorphisms -216 G>T, -191 C>A, (CA) n IVS1, and R521K.

MATERIALS AND METHODS

We studied 22 biopsies from gastric tumors obtained by endoscopy. EGFR expression was determined by relative quantification real-time polymerase chain reaction with the glyceraldehyde-3-phosphate dehydrogenase reference gene (as for messenger RNA [mRNA]) and by immunohistochemistry (IHC) (as for protein). EGFR germline polymorphisms were analyzed by sequencing, GeneScan, and restriction fragment length polymorphisms.

RESULTS

EGFR mRNA expression was increased (>2-fold) in 13.6% of GC cases, decreased (<0.5-fold) in 68.2%, and normal in 18.2%; overexpression was related to well-differentiated gastric tumors, whereas underexpression was linked to moderate or poorly differentiated gastric tumors (P < 0.001). EGFR protein expression was high (IHC 2+ and 3+) in 29.4% of gastric tumors and was normal or low (score 0 to 1+) in 70.6% cases. EGFR expression, in both mRNA and protein, was not related to any EGFR polymorphism (P > 0.05).

CONCLUSIONS

Most gastric tumors showed low EGFR expression (mRNA and protein), whereas EGFR overexpression was related to well-differentiated gastric tumors. Furthermore, germinal polymorphisms -216, -191, (CA) n IVS1, and R521K were not related to EGFR expression (mRNA or protein).

Molecular profiling of a simple rat model of open tibial fractures with hematoma and periosteum disruption

Bone fractures are a worldwide public health concern. Therefore, improving understanding of the bone healing process at a molecular level, which could lead to the discovery of potential therapeutic targets, is important. In the present study, a model of open tibial fractures with hematoma disruption, periosteal rupture and internal fixation in 6-month-old male Wistar rats was established, in order to identify expression patterns of key genes and their protein products throughout the bone healing process. A tibial shaft fracture was produced using the three-point bending technique, the hematoma was drained through a 4-mm incision on the medial aspect of the tibia and the fracture stabilized by inserting a needle into the medullary canal. Radiographs confirmed that the induced fractures were diaphyseal and this model was highly reproducible (kappa inter-rater reliability, 0.82). Rats were sacrificed 5, 14, 21, 28 and 35 days post-fracture to obtain samples for histological, immunohistochemical and molecular analysis. Expression of interleukin-1β (Il-1β), transforming growth factor-β2 (Tgf-β2), bone morphogenetic protein-6 (Bmp-6), bone morphogenetic protein-7 (Bmp-7) and bone γ-carboxyglutamic acid-containing protein (Bglap) genes was determined by reverse transcription quantitative polymerase chain reaction and protein expression was evaluated by immunohistochemistry, while histological examination allowed characterization of the bone repair process. Il-1β showed a biphasic expression, peaking 5 and 28 days post-fracture. Expression of Tgf-β2, Bmp-6 and Bmp-7 was restricted to the period 21 days post-fracture. Bglap expression increased gradually, peaking 21 days post-fracture, although it was expressed in all evaluated stages. Protein expression corresponded with the increased expression of their corresponding genes. In conclusion, a clear and well-defined expression pattern of the evaluated genes and proteins was observed, where their maximal expression correlated with their known participation in each stage of the bone healing process.

Wide clinical spectrum in Zimmermann-Laband syndrome

Gingival fibromatosis can be present as an isolated form or be part of a genetic disease. The Zimmermann-Laband syndrome (ZLS) is a rare disorder inherited as an autosomal dominant fashion, clinically characterized by gingival fibromatosis, bulbous soft nose, thick floppy ears, nail dysplasia, joint hyperextensibility, hepatosplenomegaly, skeletal anomalies and occasional mental retardation. We studied a girl aged five years with clinical and radiological features of the ZLS, additionally she presented deafness not previously described in the ZLS, as only partial hearing loss was reported in some patients. The father presented some facial features suggestive of ZLS, nevertheless he did not have gingival fibromatosis or hypertrichosis. We suggest that this case supports that ZLS can be part a contiguous genes syndrome or be consequence ofa gene mutation with wide variable expression. The present report supports that ZLS has a wide clinical spectrum.

Scanning electron microscopy of the orbital Harderian gland in the male Atlantic bottlenose dolphin (Tursiops truncatus)

The ultrastructure of the Harderian gland of Atlantic bottlenose dolphin (Tursiops truncatus) was examined by scanning electron microscopy (SEM). We found the following surface features: the typical round appearance of the ascinar glandular unit with a finely granular surface, a thin cortex and immediately below two types of cells: type I cells (characterized by small lipid vacuoles) and type II cells (characterized by large lipid vacuoles). It has been suggested that different cells forms represent a single cell type in varying activity states. Additionally, a coalescent tubular complex, a small balloon-like structures and large globular structures were observed. These structures may be reservoirs of secretion products.