Up-regulation of microRNA-302a inhibited the proliferation and invasion of colorectal cancer cells by regulation of the MAPK and PI3K/Akt signaling pathways.

Aberrant expression of microRNA-302a (miR-302a) has been frequently reported in some cancers excluding colorectal cancer (CRC). However, the role of miR-302a in CRC has not been reported. In this paper, we examined the effect of miR-302a overexpression on proliferation and invasion in CRC cells. The mRNA level of miR-302a in CRC cell lines was determined by real-time PCR. The miR-302a mimic was transiently transfected into CRC cells using Lipofectamine™ 2000 reagent. Subsequently, cell proliferation and invasion were assessed by MTT and Transwell assays. Western blot and ELISA assay were used to detect the expressions and secretions of matrix metalloproteinases (MMPs). Moreover, the expressions of epithelial marker, mesenchymal markers and transcription factors were also determined by Western blot. In addition, the effects of miR-302a overexpression on the MAPK and PI3K/Akt signaling pathways were investigated by Western blot. Our results showed that the mRNA level of miR-302a was remarkably decreased in CRC cell lines compared with normal colon epithelium cells. Up-regulation of miR-302a inhibited the proliferation and invasion of CRC cells. The expressions and secretions of MMP-9 and -2 were evidently reduced by increasing miR-302a. Besides, we found a decrease of ß-catenin, fibronection, vimentin, Snail, Slug, ZEB1 and ZEB2 expressions and an increase of E-cadherin expression. We also found that miR-302a overexpression might decrease the phosphorylation of Erk1/2 and Akt. Altogether, our results indicated that miR-302a overexpression was shown to inhibit proliferation and invasion of CRC cells by reducing the expressions of related proteins through suppressing the MAPK and PI3K/Akt signaling pathways.

Diagnostic and application value of 64-slice spiral CT scanning in preoperative staging of esophageal cancer / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the diagnostic and application value of pre-operative 64-slice spiral CT evaluation in operation selection for esophagus cancer.</p><p><b>METHODS</b>Multi-slice computed tomography (MSCT) was conducted in 50 patients with esophageal cancer before operation, using the work station for after-treatment to get CT virtual endoscopy (CTVE), multiplanar reconstruction (MRP), shaded surface display (SSD) and Raysum images, and combined with the transect images to record the preoperative MSCT staging and to predict the operation scheme, and compared with the postoperative pathological staging and the actual operational plan.</p><p><b>RESULTS</b>The diagnostic sensitivity of MSCT for preoperative T staging was 100.0% (50/50), while the N staging was 80.0% (16/20). According to the MSCT prediction, the resection rate of esophageal cancer was 96.0% (48/50). Through the preoperative MSCT evaluation, the accuracy of CT-TNM stage was 90.0%, highly consistent with the pathological TNM stage (Kappa = 0.811, P < 0.05).</p><p><b>CONCLUSIONS</b>MSCT can effectively display the shape, size and position of the tumor, determine the tumor invasion range, lymph node metastasis and distant metastasis, etc., make preoperative evaluation for esophagus cancer patients and provide evidence for clinicians to predict the operation scheme for esophagus cancer.</p>