Expression Of LncRNA-CCHE1 In Papillary Thyroid Carcinoma And Its Effect On Proliferation And Invasion Of Papillary Thyroid Carcinoma

Objective: Thyroid cancer(TC)is the most common malignant tumor in endocrine system,witha sharp rising incidence worldwide.Papillary thyroid carcinoma(PTC)accounts for more than 80% of thyroid cancers.Compared with other malignant tumors,papillary thyroid carcinoma has a low degree of malignancy,good biological behavior and slow progression.However,its recurrence rate and metastasis rate are obviously high,and dedifferentiation often leads to rapid disease progression and poor prognosis.The pathogenesis of papillary thyroid carcinoma is still unclear.With an increasing clinical understanding of thyroid papillary carcinoma,detection of potential molecular markers may exert far-reaching influence on understanding the process of the incidence and development of PTC and improving diagnostic accuracyand prognosis of thyroid papillary carcinoma.Long non-codingRNA(lncRNA)is a kind of non-codingRNA with more than 200 nucleotides in length,and with a proportion of about 80% of all non-codingRNAs,which was once considered as "junk" because they cannot encode protein.At present,a large array of studies have shown that lncRNAs are involved in cell differentiation and growth,which play a role in the genome,and are related to the pathogenesis of many diseases,including cancer.A large number of studies have confirmed that the abnormal expression of the lncRNA is closely related to the pathogenesis of the tumor,including the increase,invasion,epithelium,the transformation of the epithelial-interstitial transformation(EMT),apoptosis and anti-tumor resistance,which can play an important part in the process of epigenetic,transcriptional and post-transcriptional levels of gene expression.As one kind of lncRNAs,High expression of cervical cancer lncRNA 1(lncRNA-CCHE1)is located in the intergene region of chromosome 10 in the nucleus with the total length of 1570 bp.By binding to PCNA mRNA,the expression of PCNA was up-regulated to increase the proliferation rate of cervical cancer cells.Subsequently,lncRNA-CCHE1 expression was detected in several other cancer tissues.At present,a number of studies have shown that it is involved in the pathogenesis and development of tumors,and promotes the progression of tumors.However,the function of lncRNACCHE1 in PTC has rarely been reported,and the relation between its expression and clinicopathological features of patients is unclear.In this study,the expression of lncRNA-CCHE1 in papillary thyroid carcinoma tissues was detected,and the relation between lncRNA-CCHE1 and clinicopathological features of patients with papillary thyroid carcinoma was analyzed.After up-regulating or down-regulating the expression of lncRNA-CCHE1,the effects of lncRNA-CCHE1 on PTC cell proliferation,migration and invasion were observed,which provides basic experimental basis for further elucidating the mechanism of proliferation and invasion of lncRNA-CCHE1 in PTC and finding new targets for PTC treatment.Methods:1.To detect the expression of lncRNA-CCHE1 in PTC carcinoma tissues and its normal adjacent tissuesThe expression of lncRNA-CCHE1 in PTC carcinoma tissues and normal adjacent tissues was detected with the method of real-time quantitative polymerase chain reaction(q RT-PCR).2.To verify the effect of lncRNA-CCHE1 on the proliferation and invasion of thyroid papillary carcinoma cellslncRNA-CCHE1 was down-regulated by transfection of lncRNA-CCHE1 shRNA and up-regulated by transfection of pc DNA-CCHE1 overexpressed plasmid in papillary thyroid carcinoma cell line BCPAP cells.The cell transfection efficiency was detected by q RT-PCR.Cell Counting Kit-8(CCK8),plate cloning assay,cell wound-healing assay and transwell assay were used to analyze the effect of lncRNA-CCHE1 on PTC cell proliferation and invasion in vitro.3.Molecular mechanism of lncRNA-CCHE1 on EMT of thyroid papillary carcinoma cellsReal-time PCR was used to detect the effects of down-regulated or up-regulated lncRNA-CCHE1 on the expression of EMT-related genes E-cadherin,N-cadherin and Snail in BCPAP cells.Western blot was used to detect the effect of down-regulated or up-regulated lncRNA-CCHE1 on the expression of EMT-related gene protein in thyroid papillary carcinoma cells.Western blot was employed to observe the effects of down-regulated or up-regulated lncRNA-CCHE1 on ERK/MAPK signaling pathway.Results:1.A higher expression of lncRNA-CCHE1 was found in PTC tissues than in adjacent tissues.High expression of lncRNA-CCHE1 was positively correlated with the number of tumors,extra-glandular invasion,and tumor stage;2.The down-regulation of lncRNA-CCHE1 reduced the proliferation and inhibited the invasion of PTC cell lines,while its up-regulation caused the opposite effect;3.The down-regulation of lncRNA-CCHE1 increased the expression levels of E-cadherin mRNA and protein in BCPAP cells,and inhibited the expression levels of N-cadherin,Snail mRNA and protein,while its up-regulation caused the opposite effect;4.The down-regulation of lncRNA-CCHE1 in papillary thyroid cancer cells can significantly inhibit the expression of P-ERK and P-P38-MAPK,while its up-regulation caused the opposite effect.These effects were certificated that lncRNA-CCHE1 regulated the invasion via the extracellular signal-regulated kinase/mitogen-activated protein kinase(ERK/MAPK)pathway.Conclusions: lncRNA-CCHE1 shows an increase in expression of papillary thyroid carcinoma tissues and cells,which can affect the proliferation,invasion ability and EMT level of papillary thyroid carcinoma cells via the ERK/MAPK signaling pathway.The lncRNA-CCHE1 is closely related to PTC progression and can be used as a potential biomarker for early diagnosis and treatment of PTC.