Deletion polymorphism at chromosome 3q26.1 and oral squamous cell carcinoma

Somatic genomic imbalances in 'tumour-free' surgical margins of oral cancer

Up to 30% of oral squamous cell carcinoma (OSCC) patients develop local recurrence and distant metastasis. The molecular status of histologically cancer-free tumour margins could be a critical factor in predicting tumour behaviour. The aim of this study was to detect somatic genomic imbalances in OSCC with emphasis on the surgical margins. DNA was isolated from tumour tissues, margin tissues, and blood samples (used as control) obtained from 11 OSCC patients, and genome-wide array comparative genomic hybridization was performed. Imbalances were present in both tumours and margins, although, as expected, they were more prevalent in tumours (duplications, P = 0.0002; deletions, P = 0.0001). Duplications were more frequent than deletions in both tumours and margins, but without statistical significance. Fifteen imbalances in tumour tissues were recurrent and all of them were duplications. Four of these were found both in tumours and margins and involved chromosomes 1q, 8p, Xp, Yp, and Yq. Four imbalances were recurrent in margin tissue and all of them were duplications (autosomes 8 and 17 and both sex chromosomes). Histologically 'cancer-free' margins hide genomic alterations consistent with unexplained OSCC recurrences. Establishing the molecular status of the margins could improve outcome prediction.

miR-720 is a key regulator of glioma migration and invasion by controlling TARSL2 expression

Glioblastoma (GBM) is the most lethal type of primary brain tumor and is characterized by diffuse infiltrative growth. However, the mechanisms that control this phenotype remain largely unknown. Emerging evidence has demonstrated that the abnormal expression of microRNAs and their target genes are involved in the migration and invasion of glioma cells. In this study, we demonstrated that microRNA-720 (miR-720) was significantly upregulated in glioma tissues and cells. Functional experiments showed that overexpression of miR-720 promotes glioma migration and invasion, while downregulation of miR-720 inhibits glioma migration and invasion. Meanwhile, we found that threonyl-tRNA synthetase like-2 (TARSL2) was a direct and functional target of miR-720 in glioma. Reintroduction of TARSL2 into glioma cells repressed the invasion promoting function of miR-720, whereas downregulation of TARSL2 reversed the anti-invasion function of anti-miR-720. Furthermore, quantitative real-time polymerase chain reaction results showed that miR-720 was inversely correlated with TARSL2 expression in 40 GBM tissues. Finally, in vivo experiments showed that miR-720 promotes glioma growth and upregulates invasion-related genes in nude mice. Overall, our findings suggest increasing miR-720 enhances glioma migration and invasion through downregulation of TARSL2, which may provide novel insight into the treatment of glioma.

Structural maintenance of chromosomes 4 is a predictor of survival and a novel therapeutic target in colorectal cancer

BACKGROUND

Structural maintenance of chromosomes 4 (SMC-4) is a chromosomal ATPase which plays an important role in regulate chromosome assembly and segregation. However, the role of SMC-4 in the incidence of malignancies, especially colorectal cancer is still poorly understood.

MATERIALS AND METHODS

We here used quantitative PCR and Western blot analysis to examine SMC-4 mRNA and protein levels in primary colorectal cancer and paired normal colonic mucosa. SMC-4 clinicopathological significance was assessed by immunohistochemical staining in a tissue microarray (TMA) in which 118 cases of primary colorectal cancer were paired with noncancerous tissue. The biological function of SMC-4 knockdown was measured by CCK8 and plate colony formation assays. Fluorescence detection has been used to detect cell cycling and apoptosis.

RESULTS

SMC-4 expression was significantly higher in colorectal cancer and associated with T stage, N stage, AJCC stage and differentiation. Knockdown of SMC-4 expression significantly suppressed the proliferation of cancer cells and degraded its malignant degree.

CONCLUSIONS

Our clinical and experimental data suggest that SMC-4 may contribute to the progression of colorectal carcinogenesis. Our study provides a new therapeutic target for colorectal cancer treatment.