The Expression And Significance Of MiRNA-222 In The Tissue Of Oral Squamous Cell Carcinoma

Objective: Squamous cell carcinoma is mostly common in oral carcinoma, accounting for about 80%, ranked eighth in the systemic malignant tumors.[1]Oral squamous cell carcinoma(OSCC) often occurs in adults from 40 to 60 years of age, male more than female, and occurs more commonly in the tongue, gums, cheek, palate, lip and other parts.[2]OSCC is often developed rapidly, early into the regional lymph node metastasis, and later into distant metastasis, which seriously affects the quality of life for patients, or even threaten their lives. Oral precancerous lesion(OPL) is one of the pathological changes that may develop into cancer in the oral mucosa, OPL mainly includes oral leukoplakia(OLK), oral mucosal fibrosis(OSF) and oral erythema etc.[3]16% ~ 62% of oral squamous cell carcinoma is from the development of oral leukoplakia canceration.[4]Although OSCC has achieved great progress in treatment, the mortality rate is still very high. How to realize the early prevention, early diagnosis and effective treatment is one of the problems that the modern medical field concerns.MicroRNA(miRNA) is a kind of stable short sequence of non-coding small molecule RNA, and its main function is to participate in the regulation of target gene at the level of post-trans cription.[5] Not only can MiRNA act as oncogenes or tumor suppressor gene to play a role, but MiRNA can degrade or inhibit the translation of target messenger RNA(mRNA) to regulate the expression level of oncogenes and tumor suppressor genes. Recent studies have found out that the abnormal expression of miRNAs has existed in patients with oral squamous cell carcinoma, and these miRNAs plays an important role in theoccurrence and development in oral squamous cell carcinoma, as well as in clinical diagnosis, clinicaltreatment and prognosis judgment. These specific expressions of miRNA are expected to become the new tumor marker.MiRNA-222 is a member of the miRNA family, also known as has-mir-222, located in the p11.3 region of the X chromosome, which is expressedabnormally in a variety of tumors. In previous studies, we have demonstrated that miRNA-222 is highly expressed in peripheral blood of patients with oral squamous cell carcinoma. This study will further study the expression and significance of mi RNA-222 in normal oral mucosa, oral leukoplakia and oral squamous cell carcinoma, which will lay a foundation for studying the mechanism of mi RNA-222 in oral squamous cell carcinoma.Methods: 1 Grouping 1.1Experimental group: Select 30 cases of surgical resectionof oral and maxillofacial squamous cell carcinoma from November 2014 to May 2015 in the Fourth Hospital of Hebei Medical University, among which 15 cases for the regional lymph node metastasis are positive for, 15 cases for negative transfer;17 cases for male, 13 cases for female; 19 cases for age from 40 to 60 years old, 11 cases for other age groups. 30 cases of oral leukoplakia tissue undergo surgical resection. Sample is placed in RNA preservation solutionunder a lower temperature after being collected. 1.2Control group: Take 30 cases of oral normal mucosal tissue after a benign tumor surgical resection in the same period as control. Sample is placed in RNA preservation solution under a lower temperature after being collected. 1.3Inclusion criteria: All tissues are pathologically confirmed, and before operation radiotherapy and chemotherapy are not given. 2 Experimental methods 2.1Total RNA is extracted from tissue samples. 2.2RNA concentration and purity are detected. 2.3Total RNA synthesizes cDNA by reverse transcription. 2.4To perform qRT-PCR reactions, to monitor the expression level of mi RNA-222 in normal oral tissue, oral leukoplakia and oral squamous cell carcinoma tissue. 3 Statistical analysis:Apply SPSSl3.0 for Windows to perform data analysis, with mean ± standard deviation(x|-±SD) noted, use independent sample T-test method to make a comparisonbetween two groups, and take ANOVA to make comparisons between multiple samples. P <0.05 is considered statistically significant.Results:1. The relative expression of miRNA-222 in normal oraltissue, oral leukoplakia and oral squamous cell carcinoma tissue is respectively,0.532±0.24、0.601±0.27、2.401±0.94, with significantdifference(F =99.38, P <0.05). LSD test method is usedto make pairwise comparisons, which shows that there is no statisticaldifference(t=1.025,P>0.05) between normal oral tissue and oralleukoplakia organization; difference between normal oral tissue and oral squamous cell carcinoma tissue is statistically significant(t=10.54,P<0. 05); difference between oral leukoplakia tissue and oral squamous cell carcinoma tissue has statistical significance(t=10.08,P<0.05).2.The relative expression of miR-222 in patients with lymph node-positive and negative tissue is respectively 2.063 ± 0.81 、 2.739 ±0.97,whichis statistically significant(t=2.079,P<0.05).3. The relative expression of miR-222 in patients with oral squamous cell carcinoma tissue between 40-60 age group and other age groups is respectively 2.327±0.95 、 2.530 ± 0.95, with not statistical significance(t=0.564,P> 0.05).4.Therelative expression of miR-222 in male and female patients with oral squamous cell carcinoma tissue is respectively2.368±0.97、2.445±0.94, with no statistical significance(t=0.052,P>0.05).Conclusion:1The high expression of mi RNA-222 in OSCC suggests that mi RNA-222 may play an important role in the occurrence and development of OSCC;2There was no differential expression of miRNA-222 in OLP, which suggests that miRNA-222 might not be involved in OLPcanceration;3The expression level of miRNA-222 in OSCC is related to lymph node metastasis, but not related to age and sex, whichsuggest that miRNA-222 may regulate the metastasis of OSCC.