Expression And Significance Of EGFR And LRIG1 In Esophageal Carcinoma

Background and ObjectivesEsophageal carcinoma is one of the most common digestive tumors in human disease,and esophageal squamous cell carcinoma is more common. Three hundred thousands people died from it in the world every year and half of those are in china.The incidence and mortality has obvious regional differences.It has done great harm to people's health. The epidemiological date confirmed that age, sex, occupation, race, geographical living environment, dietary habits and genetic factors have close relation with the incidence of esophageal carcinoma.With the development of molecular biology,it may be studyed by the level of molecular. The development and progression of esophageal carcinoma involve in the anti-oncogene inactivation and oncogene activation.Its clinical symptoms are not obvious in early tumor phase,which makes patient receive early diagnosis become a problem. The esophageal patients as other digestive tumors will lose their lives because of metastasis or recurrence of tumor,even though positive treatment. Thus, it is extremely important to research the molecule mechanisms t of esophageal carcinoma.EGFR(epidermal growth factor receptor,EGFR) belongs to I type transmembrane tyrosine kinase growth factor receptor, EGFR gene situated in the 7pl3-q22 position. EGFR gene codes 170-180KD across a cell membrane glycoprotein. Its structure consists of three parts:exocellular ligand-binding area, transmembrane area and intracellular area,including intracellular area with tyrosine kinase activity. EGFR in human multiple tumors were expressed or high expression, all of that finds out that EGFR may play a part in the progression or development of tumor. EGFR bindings its ligand activates a series of signal transduction system of downstream,and finally causes increase of transcriptional level of intranuclear response genes which stimulate cell proliferation and transformation.Existing research shows that it is through its EGFR signal transduction pathways control the growth of tumor cells.In addition, it's closely associated with tumor cells antiapoptotic,angiogenesis,tumor invasion and metastasis.LRIG1(Ieucine-rich repeats and immunoglobulin-like domains-1, LRIG1) is a transmembrane carbohydrate protein which Combined with epidermal growth factor receptor(EGFR) produce negative feedback effects. LRIG1 gene situated in the 3p14.3 position.This area in many human malignant tumor cells are often missing.The expression of LRIG1 protein was found in the human genome by Nilsson etc.Their study find that the expression level of LRIG1 gene in tumor tissue was deletion or lower.These tips LRIG1 gene may be a tumor suppressor gene and play a role in development and progression of tumor.The expression and correlation studies on EGFRmRNA and LRIGlmRNA in esophageal squamous carcinoma have not been reported. In this case, we use reverse transcription polymerase chain reaction(RT-PCR) to detect the expression of EGFRmRNA and LRIGlmRNA in esophageal carcinoma and normal para-cancer tissues,matched humanβ-actin,and to analyze the relationship between development of esophageal cancer and clinical pathology,so as to provide theoretical evidence on mechanism of occurrence and development of the esophageal cancer.Materials and Methods1. From January 2010 to May 2010,46 cases of cancer tissues and 46 cases of normal para-cancer tissues were taken from department of thoracic surgery,the second affiliated hospital of Zhengzhou University which were confirmed postoperative by pathological diagnosis.46 cases of normal para-cancer tissues were selected as control group,which were obtained from the patients with esophageal carcinoma 5 cm far from tumor tissue. All the cases hadn't been treated by radiation treatment or chemotherapy.All the cases have complete clinical date and pathological diagnosis.2. RT-PCR was used to detect the expression of EGFR,LRIG1 in the 46 cases of cancer tissues and normal para-cancer tissues so as to analyze the relationship of gene expression of EGFR, LRIG1 and clinical pathological feature in cancer tissues.3. All statistical analyses were used by using the statistical package for SPSS 13.0.The association of variables was evaluated by using,one-way ANOVA, t-test,pearson analysis,etc.the difference was considered as significant if a value was less than 0.05.Results1. The expression level of EGFRmRNA in esophageal carcinoma tissues (2.232±0.253) was higher than that in normal para-cancer tissues (1.878±0.213) (p< 0.05);2. The expression level of LRIGlmRNA in esophageal carcinoma tissues (0.348±0.041) was lower than that in normal para-cancer tissues(0.672±0.073) (p< 0.05);3. The expression level of EGFRmRNA is not directly correlated with age, sex, tumor differentiation, the staging and lymphatic metastasis (p>0.05);4. The expression level of LRIGlmRNA is not directly correlated with age, sex, tumor differentiation, the staging and lymphatic metastasis (p>0.05);5. There is negative correlation between LRIGlmRNA and EGFRmRNA in the expression level of esophageal carcinoma tissues and normal para-cancer tissues,there are significant differences between them(r=-0.662, p<0.05).Conclusions1. The expression level of EGFRmRNA in esophageal carcinoma tissues was higher than that in normal para-cancer tissues,which tips that the high expression level of EGFR starts signal transduction pathways lead to epithelial hyperplasia signal transduction unusual.Thus,the growth of cell lose control lead to the development of tumor cell;2. The expression level of LRIGlmRNA was lower than that in normal para-cancer tissues,which reveals that the low expression of LRIG1mRNA leads to the reduction of inhibition signal and active it,results in normal cells reproduced become tumor cells,these tips LRIG1 gene may be an anti-oncogene;3. The expression level of EGFRmRNA is not correlated with age, sex, tumor differentiation, the staging and lymphatic metastasis,which is different from other documents.It may because of the small sample;4. The expression level of LRIGlmRNA is not correlated with age, sex, tumor differentiation, lymphatic metastasis and the staging,which shows that LRIG1mRNA expression level can't decide esophageal pathology classification;5. There was negative correlation between the expression level of EGFRmRNA and LRIG1mRNA,which reveals that LRIG1 may be indirect regulator to EGFR so as to keep relatively balance and make tissue metabolism stable.