Expression And Significances Of MiRNA Let-7 And HMGA2 In Laryngeal Carcinoma

Objective: By observing the expressions of mi RNA let-7a and HMGA2 in the human laryngeal carcinoma,analyzing the relationship between the expression levels and clinicopathological factors in laryngeal carcinoma,to explore the relationship between each other and its correlation with laryngeal cancer occurrence, development, and thus provide a new theoretical basis for clinical diagnosis and treatment of laryngeal cancer.Methods: 1.25 pairs of fresh laryngeal cancer tissues and adjacent normal tissues which is 0.5cm-1.0cm from the cancerous tissues. The expressions of mi RNA let-7a and HMGA2 m RNA were detected by real-time quantitative RT-PCR. 2.50 pairs paraffin specimen of laryngeal cancer tissues and adjacent normal tissues which is 0.5cm-1.0cm from the cancerous tissues. The expressions of HMGA2 protein were detected by immunohistochemistry. 3.Clinical data of all patients was collected over the same period. The relationship of clinic pathological factors and the expressions of mi RNA let-7a and HMGA2 protein in laryngeal cancer was analyzed.Results: 1.There is a significant difference the expression of mi RNA let-7a between the human laryngeal cancer tissues and adjacent normal epithelial mucosa tissues, P <0.05.2. The expressions of HMGA2 m RNA and HMGA2 protein between the human laryngeal cancer tissues and adjacent normal epithelial mucosa tissues both have a significant difference, P <0.05.3.There is a negative correlation the low expression of mi RNA let-7a and high expression of HMGA2 m RNA in human laryngeal cancer, P <0.05.4.The human laryngeal cancer tissues specimen was grouped according to clinicopathological factors. The expressions of mi RNA let-7a have significant difference, P<0.05, between groups of clinic stageⅠ-Ⅱ and clinic stageⅢ-Ⅳ, well-differentiated group and poorly differentiated group, with lymph node metastasis group and without lymph node metastasis group. The expressions of HMGA2 protein have significant difference, P <0.05, between groups of clinic stageⅠ-Ⅱ and clinic stage Ⅲ-Ⅳ, well-differentiated group and poorly differentiated group, with lymph node metastasis group and without lymph node metastasis group.Conclusions: 1. In human laryngeal carcinoma the expression of mi RNA let-7a are significantly lower than the control group,this indicates that mi RNA let-7a is a tumor suppressor gene.2 In human laryngeal carcinoma the expression of HMGA2 m RNA and HMGA2 protein are both significantly higher than the control group. HMGA2’s laryngeal cancer tissue-specific expression,suggests that HMGA2 is one of the molecular markers of laryngeal cancer.3. In human laryngeal carcinoma the expressions of mi RNA let-7a and HMGA2 m RNA is negatively correlated,this indicates that mi RNA let-7a may negatively regulate the expression of HMGA2 in laryngeal cancer.4. In human laryngeal carcinoma the low expression of mi RNA let-7a and high expression of HMGA2 both have a relationship with laryngeal cancer clinical staging,tumor differentiation and lymph node metastasis, which means,when the laryngeal cancer clinic stage gets later, when the differentiated level gets lower, when with lymph node metastasis, the expression of mi RNA let-7a gets lower and the expression of HMGA2 gets higher.This indicates that the downregulation of mi RNA let-7a and upregulation of HMGA2 promotes the invasion and metastasis of laryngeal cancer.