To explore the relationship between long non-coding RNA colon cancer related transcript 1 （lncRNA CCAT1），microRNA-152 （miR-152） expression and proliferation/invasion genes expression and clinicopathological characteristics in triple negative breast cancer （TNBC）.

A total of 120 TNBC tissue samples and paired adjacent normal tissue samples were collected from surgical resections performed in the Baoding Second Central Hospital from July 2021 to June 2024. The expression levels of lncRNA CCAT1，miR-152 and proliferation-related genes （EZH2，PIWIL2，YAP1），as well as invasion-related genes （GLI1，TUG1，RAB11），were detected using real-time quantitative PCR. Binding sites between lncRNA CCAT1 and miR-152 were predicted using the StarBase database. Pearson correlation was used to analyze correlations between the expression levels of lncRNA CCAT1，miR-152 and the expression levels of proliferation and invasion related genes in TNBC tissues. For normally distributed measurement data, an independent samples t-test was used for comparisons between two groups, analysis of variance for comparisons among multiple groups and paired t-test was used for comparisons with adjacent non-tumor tissues. The relationship between the expression of lncRNA CCAT1 and miR-152 in TNBC tissue and proliferation genes，invasion genes and clinical pathological characteristics were analyzed by stepwise multiple linear regression.

Compared with adjacent normal tissues，TNBC tissues exhibited significantly higher expression levels of lncRNA CCAT1，EZH2 mRNA，PIWIL2 mRNA，YAP1 mRNA，GLI1 mRNA，TUG1 mRNA，and RAB11 mRNA，while miR-152 expression was significantly decreased （all P<0.001）. Binding sites between lncRNA CCAT1 and miR-152 were identified，and their expression levels in TNBC tissues showed a negative correlation （r=-0.761，P<0.001）. Pearson correlation analysis revealed that lncRNA CCAT1 expression was positively correlated with the mRNA expression of EZH2，PIWIL2，YAP1，GLI1，TUG1，and RAB11 （r=0.716，0.685，0.702，0.734，0.726，0.688； all P<0.001），whereas miR-152 expression was negatively correlated with the mRNA expression of these genes （r=-0.713，-0.702，-0.698，-0.721，-0.716，-0.703； all P<0.001）. The expression levels of lncRNA CCAT1 in TNBC tissues with tumor diameter >2 cm，histological grade 3，TNM stage Ⅲ and lymph node metastasis were significantly higher than that with tumor diameter ≤2 cm，histological grade 1–2，TNM stage Ⅰ–Ⅱ and no lymph node metastasis （t=2.529，F=20.827，t=2.944，t=3.172； P=0.013，<0.001，0.004，0.002），the expression levels of miR-152 were significantly lower than that with tumor diameter ≤2 cm，histological grade Ⅰ/Ⅱ，TNM stage Ⅰ–Ⅱ and no lymph node metastasis （t=-2.481，F=-10.611，t=-2.936，t=-3.160； P=0.015，<0.001，0.005，0.002）. The expression level of lncRNA CCAT1 in TNBC tissue were positively correlated with the mRNA expression of EZH2，PIWIL2，YAP1，GLI1，TUG1，RAB11，as well as tumor diameter，histological grade，TNM staging and lymph node metastasis status （OR=3.203，2.807，2.034，4.425，4.476，2.185，2.074，3.127，2.255，4.972； P=0.002，0.006，0.044，<0.001，<0.001，0.031，0.040，0.002，0.026，<0.001）. The expression level of miR-152 were negatively correlated with the gene expression and clinical pathological indicators mentioned above （OR=-2.543，-2.787，-2.120，-2.856，-3.498，-2.403，-2.225，-3.200，-2.819，-4.284； P=0.012，0.006，0.036，0.005，0.001，0.018，0.028，0.002，0.006，<0.001）.

lncRNA CCAT1 is highly expressed and miR-152 is lowly expressed in TNBC tissues，which are closely related to the enhanced proliferation，invasion ability of TNBC cells and poor clinicopathological characteristics of patients，and may become a biomarker for evaluating the malignant progression of TNBC.