Defining the regulatory role of programmed cell death 4 in laryngeal squamous cell carcinoma.

Programmed cell death 4 (PDCD4) is decreased in many different kinds of malignant tumors. EMT endows tumor cells invasive and metastatic properties. However, few studies have determined the role of PDCD4 in the regulation of EMT in the context of laryngeal carcinoma. We examined the relationship between PDCD4 and EMT-associated proteins E-cadherin and N-cadherin using laryngeal carcinoma tissues. Gene manipulation was used to define the regulatory capacity of PDCD4. We report that PDCD4 and E-cadherin/N-cadherin expression were significantly changed in the carcinoma tissues, and their expression was associated with pathological grade, metastatic state, and clinical stage. The suppression of PDCD4 (and consequently, E-cadherin) was concomitant with increased proliferation and G2-phase arrest, decreased apoptosis, and increased cell invasion. PDCD4 upregulation reversed the above-mentioned results. In nude mice, PDCD4 knockdown increased tumor growth and pathological features, confirming the tumorigenic role of PDCD4. Finally, PDCD4 silencing was associated with dysregulation of the carcinogenic Wnt-ß-catenin and the STAT3-miR-21 signaling pathways. This study revealed a dynamic regulatory relationship between PDCD4 and critical factors for EMT, establishing a broad, functional role for PDCD4 in laryngeal carcinoma, which may be propagated by the STAT3-miR-21 pathway. These findings provide new information on an EMT-associated target that may lead to a novel therapy.

Detection of Alternatively Spliced or Processed RNAs in Cancer Using Oligonucleotide Microarray.

Deregulation of gene expression plays a pivotal role in tumorigenesis, so the ability to detect RNA alterations is of great value in cancer diagnosis and management. DNA microarrays have been used to measure changes in mRNA or microRNA level, but less often the change of RNA isoforms. Here we appraise the utilization of microarray in detecting alternatively processed RNAs, which have alternative splice forms, retained introns, or altered 3' untranslated regions. We cover the methodology and focus on cancer studies. Recent development in parallel or deep sequencing used in transcriptome analysis is also discussed.

[Primary functional analysis of CK13 gene 5' flanking region].

OBJECTIVE: To investigate the mechanism of cytokeratin 13 (CK13) gene expression control and the effects of different motifs of CK13 gene 5' flanking region on its transcriptional activity. METHODS: The molecular clone technique and reporter gene analysis were used to assay the effects of different motifs of 513 bp of CK13 gene 5' flanking region on its transcriptional activity. The pCAT enhancer vectors with different motifs of CK13 gene 5' flanking region were constructed and transferred to HeLa cells with the help of lipofectin. The instant CAT expression of different clones was detected and the effects of different motifs of the CK13 gene 5' flanking region on its transcriptional activity were evaluated. RESULTS: 119 bp from -nt.325 to -nt.207 upstream of the first ATG of CK13 gene 5' flanking region included a silent element. 113 bp region from -nt.206 to -nt.94 included an enhanced element. CONCLUSION: 513 bp of CK13 gene 5' flanking region includes a silent element and an enhanced element. Further locating these cis elements and detecting the related trans reaction factors may unveil some important clues to the details of the mechanisms for the CK13 gene expression and tissue-specific expression.

[Pathological features and clinical managements of nasopharyngeal angiofibroma].

OBJECTIVE: To study the pathological features of nasopharyngeal angiofibroma (NA) and the principles for clinical managements. METHODS: Thirty-five patients with NAs were treated in First Affiliated Hospital of Fujian Medical University from Oct. 1981 to May 2007. The pathological changes, sites of origin, causes of intraoperative bleeding and the experiences of managements were retrospectively analysed. Using Fish stage: 6 cases were in stage I, 8 cases were in stage II, 17 cases were in stage III, 4 cases were stage IV. Two cases via endoscopic surgery, 2 cases via palatal approach, 19 cases via midfacial degloving approach, 9 cases via lateral rhinotomy approach, 3 cases via craniofacial combined approach. RESULTS: In nasal cavity and paranasal sinus, the tumor was covered by squamous or columnar epithelium. The tumor extensions such as in pterygopalatine fossa and infratemporal fossa were covered by fibrous pseudocapsule. All cases of this series originated in the lateral wall of posterior portion of the nasal cavity. Fifteen of thirty-five cases confidentially originated near sphenopalatine foramen. Large and thick vessels in the pedicle region were the exact sites of serious intraoperative bleeding. Thirty-one cases were totally removed. Four cases were subtotal resected. Visual loss revealed in 6 cases, 4 cases visual acuity improved postoperatively. Three cases revealed postoperative dry eye due to surgical involvement of the sphenopalatine ganglion. CONCLUSIONS: nasopharyngeal angiofibroma is covered by epithelium or pseudo-capsule, it does not infiltrate the surrounding tissue. Dissecting along the surface of tumor might decrease bleeding and facilitate removal of tumor. An ideal surgical management should be done according to actually size and image examination, to the greatest extent keeping normal facial appearance. Attention should be paid to the complications such as visual loss and dry eye.