Critical Role of p53 and K-ras in the Diagnosis of Early Colorectal Cancer: a One-year, Single-center Analysis.

Background: Colorectal cancer (CRC) is strongly associated with colorectal polyps, which has become the third most common cancer in China. In the present study, we revealed the susceptible population and risk factors of colorectal polyps, and analyzed the expression of Ki-67, p53 and K-ras in the intestinal mucosa of patients with colorectal polyps in order to explore their significance in the detection and prognosis of CRC at an early stage. Materials and Methods: Total 801 cases of colorectal polyps were collected during endoscopic resection including endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD). Expression of Ki-67, p53 and K-ras in the intestinal mucosa was detected by immunohistochemistry and quantitative real-time polymerase chain reaction (qRT-PCR), respectively. Histological analysis was performed by Hematoxylin and eosin (HE) staining. Categorical variables were compared by one-way ANOVA, Pearson test, Spearman test, Kruskal-Wallis test and analysis of regression. Results: Of all patients with colorectal polyps, 90.76% of patients (n = 727) were ≥ 50 years old. 530 cases (66.17%) were males compared with 271 females (33.83%) in all 801 cases. More importantly, 1.03% patients (n = 7) underwent polypectomy and histological examination was confirmed to be the early stage of CRC. The expression of p53 was found to be significantly decreased, while K-ras was increased in tumor tissues of CRC compared with that in hyperplastic polyps and healthy controls. Conclusions: 1.03% patients (n = 7) underwent polypectomy was confirmed to be the early stage of CRC. Histological analysis for expression of p53 and K-ras can guarantee to screen the early stage of CRC.

Micro RNA-155 plays a critical role in the initiation of food allergen-related inflammation in the intestine.

The pathogenesis of food allergy (FA) is to be further investigated. Regulatory B cells (B10 cell) play a critical in the maintenance of the homeostasis in the intestine. Deregulation of B10 cell is associated with immune inflammation. Micro RNA (miR) 155 is involved in affecting immune cell function. This study tests a hypothesis that miR-155 affects the B10 cell function to facilitate the initiation of FA. In this study, BALB/c mice were sensitized to ovalbumin (OVA) to induce FA-like inflammation in the intestine. B cells were isolated from the intestine by magnetic cell sorting. The expression of miR-155 and IL-10 in B cells was assessed by real time RT-PCR. The results showed that mice sensitized to OVA showed FA-like inflammation and lower frequency of B10 cell in the intestine. B cells isolated from the intestine of FA mice showed higher levels of miR-155 and lower levels of IL-10. Although all the three T helper (Th)2 cytokines, including interleukin (IL)-4, IL-5 and IL-13, were higher in the serum, only IL-13 was positively correlated with the levels of miR-155 in the intestinal B cells. Exposure to IL-13 in the culture markedly increased the expression of miR-155 and suppressed the expression of IL-10 in B cells. Blocking miR-155 abolished the IL-13-induced IL-10 suppression in B cells and inhibited FA response in mice. In conclusion, miR-155 plays a critical role in the initiation of FA in mice. Blocking miR-155 has therapeutic potential in the treatment of FA.

[Cloning of GmHSFA1 gene and its overexpression leading to enhancement of heat tolerance in transgenic soybean].

Heat shock transcription factors (HSFs) are important in regulating heat stress response by mediating expression of heat shock protein (HSP) genes in various plant species. In the present study, a novel GmHSFA1 with an ORF of 1,533 bp (full-length cDNA sequence of 1,781 bp) was cloned from soybean genome via comparative genomic approach and RACE (rapid amplification of cDNA ends). This gene encodes 510 amino acids consisting of a protein of 56.2 kDa (GenBank accession number: AY458843). Similar to other HSFs, GmHSFA1 has the basic modular structure including DBD, OD, NLS, and CTAD. BLAST analysis revealed the identity of 52.46% between amino acid sequences between GmHSFA1 and LpHSFA1 that has the highest similarity to GmHSFA1 in all HSFA1s in various plant species. The results from RT-PCR, Northern blotting, and transformation showed: 1) GmHsfA1 exhibited the constitutive expression patterns in different tissues of soybean; 2) The expression level of GmHsfA1 in transgenic plants was notably higher than that in non-transgenic plants; 3) Overexpression of GmHsfA1 activated transcription of GmHSP22 in transgenic plants under normal conditions and enhanced obviously expressions of GmHSP23 and GmHSP70 in transgenic plants under heat stress conditions; 4) Heat tolerant temperature (as high as 52 degrees C) of transgenic plants was remarkably higher than that of non-transgenic plants. These results preliminarily proved that the overexpression of GmHsfA1 possibly led to the notable enhancement of heat-tolerant level of transgenic plants by mediating the activation of transcription or improvement of expression of some GmHSPs in the GmHsfA1's downstream in transgenic plants, suggesting GmHSFA1 is a novel and functional heat shock transcription factor of soybean.