| Objective: Leiomyosarcoma is a malignant soft tissue tumor that originates in smooth muscle cells and accounts for about one quarter of soft tissue sarcomas.Since smooth muscle cells are present in almost all organs,leiomyosarcoma can occur in any part of the body but occurs mainly in the uterus(uterine leiomyosarcoma)or retroperitoneal and deep soft tissues(non-uterine leiomyosarcoma).The prognosis of leiomyosarcoma is poor,because its treatment is mainly based on surgery and the disease is easy to metastasize.Its sensitivity to radiotherapy and chemotherapy is poor,and the newly emerging targeted therapy has no advantage in the treatment of leiomyosarcoma.Obviously,the 5-year survival rate of leiomyosarcoma is only 64%.Therefore,in order to improve the prognosis of patients with leiomyosarcoma,it is necessary to explore the factors that affect the proliferation and invasion of leiomyosarcoma cells and affect their chemosensitivity,so as to effectively interfere with these factors.It is important to improve the survival and quality of life in patients with leiomyosarcoma.Micro RNAs(miRNAs)are small,non-coding RNAs that regulate gene expression at the post-transcriptional level.They are involved in almost all biological processes,many of which have been clearly identified as potential oncogenes or tumor suppressor genes.Recently discovered miR-506 plays a very important role in the regulation of cell proliferation,differentiation,migration and invasion.Studies have shown that the imbalance of miR-506 expression has been reflected in many types of tumors.In most tumors,the expression of miR-506 is decreased compared with normal tissues,including ovarian cancer,liver cancer,breast cancer,and gastric cancer.Colon cancer,esophageal cancer,pancreatic cancer,etc.However,the expression of miR-506 is increased in lung cancer and malignant melanoma.Studies in serous ovarian cancer suggest that miR-506 can inhibit epithelial to mesenchymal transition(EMT)by targeting Slug;also studies have shown that miR-506 can increase cancer cell DNA by inhibiting RAD51 Damage Sensitivity of Chemotherapy Drugs So far,however,the expression of miR-506 in leiomyosarcoma and its iological effects remain.No relevant report was found.Therefore,the purpose of this study was to explore the miR-506 expression changes in leiomyosarcoma tissue and its clinical significance,while exploring the specific biological significance of miR-506 and leiomyosarcoma and the development of potential treatment of leiomyosarcoma means Provide evidence.Methods: The study selected 61 patients who were diagnosed at the Medical University Of Tianjin cancer hospital from January 2000 to December 2012 and were diagnosed with leiomyosarcoma in the Department of pathology of the hospital,and then consulted,collected and followed up their medical records.Thirty-seven of the 61 patients had fresh specimens.Twelve of the 37 patients with fresh specimens also had corresponding adjacent tissues.We used Quantitative Real-time PCR(q RT-PCR).The relative quantification of miR-506 expression levels in the 37 adjacent fresh leiomyosarcoma specimens and 12 of these patients’ paracancerous tissues was performed,and the differential expression of miR-506 in cancer and adjacent tissues was analyzed..The tumor tissues of 61 patients with leiomyosarcoma were collected from the Department of Pathology,Tianjin Medical University Hospital,and professionally produced tissue microarrays.Immunohistochemistry SP staining was used to stain the microarray to detect MET-related protein in the tissue: epithelial type E-cadherin,Vimentin,N-cadherin,β-catenin,Slug and DNA damage homologous recombination repair related indicators protein RAD51,RAD52,ATM,ATR expression,and then follow-up correlation analysis.Chi-square test analysis was used to analyze the correlation between the expression of miR-506,the related marker proteins,and the clinicopathological features of the patients.Kaplan-Meier analysis was used to analyze the effect of miR-506 expression and the expression of related protein on the overall survival and progression-free survival of patients with leiomyosarcoma.After miR-506 was up-regulated or inhibited in the leiomyosarcoma cell line SK-LMS-1,MTT assay,plate colony formation assay,Wound Healing,and Transwell migration invasion assay were used to verify the effect of miR-506 on smooth muscle Effect of sarcoma cell SK-LMS-1 on proliferation,migration,and invasiveness;Western blotting was used to further verify that miR-506 affects MET-related proteins(E-cadherin,β-catenin,N-cadherin,Vimentin,and Slug)and DNA The effect of repair on the repair of homologous recombination repair-related proteins(RAD51,RAD52,ATM,ATR);The effect of miR-506 on drug sensitivity of leiomyosarcoma cells to cisplatin and pirarubicin was examined by MTT and Western blot.Results: 1.The results of q RT-PCR showed that the expression of miR-506 in fresh specimens of leiomyosarcoma was lower than that in adjacent tissues(n=12,P=0.026),and the patients were divided according to the median expression of miR-506.In the miR-506 high expression group and the miR-506 low expression group,the overall survival of the miR-506 high expression group was better than that of the miR-506 low expression group(OS: n=37,P=0.038).This suggests that the expression of miR-506 helps to improve the prognosis of patients with leiomyosarcoma.2.The relationship between miR-506 and MET: 1)The positive expression rates of E-cadherin,β-catenin,Vimentin,N-cadherin,and Slug in leiomyosarcoma tissues were 29.5%,54.1%,65.6%,41.0%,and 65.6%,respectively.Correlation test showed that there was a negative correlation between the positive expression of E-cadherin and Vimentin in leiomyosarcoma tissues(r=-0.521,p<0.001),and there was a positive correlation between the positive expression of E-cadherin and β-catenin(r=0.303,p).= 0.020),positive correlation between E-cadherin and Slug positive expression(r=0.379,p=0.026);positive correlation between Vimentin and N-cadherin expression(r=0.255,p=0.049),positive expression of Vimentin and Slug Positive correlation(r=0.323,p=0.011).There was a positive correlation between the positive expression of E-cadherin and β-catenin in miR-506 and MET-related proteins(r=0.375,P=0.003;r=0.496,P=0.001),and positive expression of N-cadherin,Vimentin,and Slug.Negative correlation(r =-0.537,P = 0.011;r =-0.621,P = 0.001;r =-0.348,P = 0.03).This suggests that the expression of miR-506 can promote the occurrence of MET process in leiomyosarcoma tissues.2)Kaplan-Meier survival analysis showed that patients with positive expression of Vimentin and N-cadherin had poorer clinical outcomes than patients with negative expression.3)In the leiomyosarcoma cell line SK-LMS-1,MTT assay,plate colony formation assay,scratch test,and Transwell chamber assay were performed.The results showed that upregulation of miR-506 expression significantly inhibited the proliferation and migration of leiomyosarcoma cells.Invasive ability;Down-regulation of miR-506 expression can promote leiomyosarcoma cell proliferation,migration and invasion.4)Up-regulation of miR-506 expression in the leiomyosarcoma cell line SK-LMS-1 can increase the expression of E-cadherin and β-catenin and decrease the expression of N-cadherin,Vimentin and Slug,and down-regulate the expression of miR-506.The expression of E-cadherin and β-catenin were significantly decreased and the expression of N-cadherin,Vimentin and Slug were significantly increased.This suggests that the expression of miR-506 can promote the occurrence of MET process in leiomyosarcoma cells.3.Relationship between miR-506 and DNA damage homologous recombination repair signaling pathway: 1)The positive expression rates of RAD51,RAD52,ATM and ATR in leiomyosarcoma tissues were 45.9%,62.3%,16.4% and 60.7%,respectively.The positive expression of RAD51 was positively correlated with the positive expression of RAD52,ATM and ATR(r=0.581,p<0.001;r=0.303,p=0.018;r=0.338,p=0.008).The positive expression of RAD52 was positive with ATM and ATR.The expression was positively correlated(r=0.344,p=0.007;r=0.343,p=0.007).There was a negative correlation between miR-506 and the positive expression of RAD51,RAD52,ATM and ATR in DNA repair homologous recombination repair-related proteins(r=-0.467,P=0.001;r=-0.526,P=0.007;r=-0.358,P=0.009;r=-0.343,P=0.016).This suggests that the expression of miR-506 can inhibit DNA damage homologous recombination repair signal pathway in leiomyosarcoma tissue.2)Kaplan-Meier survival analysis showed that patients with positive expression of RAD51,RAD52,ATM,and ATR had worse clinical outcomes than patients with negative expression.3)Up-regulation of miR-506 in the leiomyosarcoma cell line SK-LMS-1 can cause a significant decrease in RAD51,RAD52,ATM,and ATR;down-regulation of miR-506 expression can cause significant increases in RAD51,RAD52,ATM,and ATR high.This suggests that the expression of miR-506 can inhibit DNA damage homologous recombination repair signal pathway in leiomyosarcoma tissue cells.4)After up-regulation of miR-506 expression in the leiomyosarcoma cell line SK-LMS-1,the sensitivity of the tumor cells to the chemotherapeutic drugs cisplatin and pirarubicin was increased;whereas the downregulation of miR-506 expression was followed by the tumor cells to chemotherapy The susceptibility of drugs cisplatin and pirarubicin decreased,that is,drug resistance increased.Conclusion MiR-506 expression in leiomyosarcoma decreased compared with peripheral normal tissues,and patients with higher miR-506 expression had longer overall survival than patients with lower miR-506 expression.miR-506 can regulate MET pathway by up-regulating the expression of E-cadherin and β-catenin and down-regulating the expression of Vimentin,N-cadherin and Slug,thus inhibiting the proliferation,migration and invasion of leiomyosarcoma cells;Mi R-506 can also Down-regulate the expression of RAD51,RAD52,ATM and ATR to regulate DNA damage homologous recombination repair pathway and enhance the resistance of tumor cells.These results suggest that miR-506 may act as a tumor suppressor gene in leiomyosarcoma. |
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