Expression And Clinical Significance Of Long Non-coding RNA SNHG3 In Breast Cancer

BackgroundBreast cancer(BC),the most common cancer type and the second dominating cause of cancer-related death in women in the United States,has now been a research hotspot.Cancer development is a multi-factor and multi-step complex process,we have been studying pathogenic factors,pathogenesis and effective treatment on cancer.Previous gene research on breast cancer has focused on DNA and protein-coding RNA.With the development of genome-wide sequencing technology,the role of non-coding RNAs(ncRNAs)has become more and more important.Long non-coding RNAs(LncRNAs)is a class of ncRNAs which was once known as "transcriptional noise" because of lack of understand on their function.More and more studies demonstrated that lncRNAs play important roles in various biological process such as cell differentiation,apoptosis,proliferation,cell invasion and metastasis.H19 is the first discovered LncRNA in breast cancer,since then,researchers have discovered lots of LncRNAs that the total number of LncRNAs detected so far exceeds protein-coding RNA.Recent studies have shown that LncRNA SNHG3 is up-regulated in liver cancer and colorectal cancer,and associated with poor prognosis.The study shows that SNHG3 promotes colorectal cancer cell proliferation and SNHG3 may be associated with tumor growth,invasion and metastasis.However,the expression level and clinical significance of SNHG3 in breast cancer have not been reported yet.The expression level of LncRNA SNHG3 in 74 pairs of breast cancer tissues and paired adjacent non-tumorous tissues was detected by qRT-PCR.Correlation of LncRNA SNHG3 expression with clinical and pathological data of breast cancer was analyzed.ObjectiveThe expression level of LncRNA SNHG3 in breast cancer tissues and paired adjacent non-tumorous tissues was detected and its correlation with clinicopathological features was analyzed.Methods1.The qRT-PCR method was used to detect the expression of LncRNA SNHG3 in 74 pairs of breast cancer tissues and paired adjacent non-tumorous tissues which pathologically confirmed by Nanjing Jinling Hospital during January 2014 to December 2017.Sample t-test was used to compare the expression of SNHG3 between breast cancer tissues and paired adjacent non-tumorous tissues.2.We analyzed the correlation between LncRNA SNHG3 expression and clinicopathological features of breast cancer.Clinical pathological indicators include:age,menopausal status,tumor size,axillary lymph node status,estrogen receptor(ER),progesterone receptor(PR),human epidermal growth factor receptor protein 2(HER2)and proliferation index(Ki-67).Correlation analysis of SNHG3 expression and clinicopathological features in breast cancer was performed using analysis of variance.Results1.The expression level of IncRNA SNHG3 in breast cancer tissues was significantly lower than that in paired adjacent non-tumorous tissues,and the difference was statistically significant(P<0.0001).2.The low expression of SNHG3 was closely related to Ki-67(P=0.013)and had no correlation with other clinicopathological features.Conclusions SNHG3 is significantly down-regulated in breast cancer tissue,and its expression level is related to Ki-67,suggesting that SNHG3 may be involved in tumorigenesis and development as a tumor suppressor gene in breast cancer,and may become a potential diagnostic molecular marker and therapeutic target for breast cancer.