Q-J Bi1, X-J Men, R Han, G-L Li. 1. Department of Oncology, Fourth People's Hospital of Zibo, Zibo, Shandong, China. ll77713@163.com.
Abstract
OBJECTIVE: LIM homeobox domain 6 (LHX6) is emerging as a critical regulator in carcinogenesis and tumor progression. The previous study has reported the expression and function of LHX6 in breast cancer (BC). However, its mechanism underlying BC metastasis remains largely unclear. This study aimed to investigate the related mechanisms of the tumor-suppressive role of LHX6 in BC. PATIENTS AND METHODS: Quantitative Real-time PCR (qRT-PCR) and Western blotting were used to determine LHX6 mRNA levels and protein expressions in BC tissues and cell lines. LHX6 protein expression was also analyzed in BC tissues and matched normal breast tissues using immunohistochemistry (IHC). The biologic functions of LHX6 in BC were explored by CCK-8 assay, colony formation assay, and transwell assays in vitro. Finally, we investigated the effect of LHX6 up-regulation on PI3K/AKT/mTOR pathway by Western blot. RESULTS: Our results showed that LHX6 was lowly expressed at the mRNA and protein level in BC cancer tissues and cell lines. Ectopic expression of LHX6 in MDA-MB-231 and T-47D suppressed cell growth, migration, and invasion. Mechanistically, our further investigations revealed that the upregulation of LHX6 inhibited the activation of the PI3K/Akt/mTOR signaling pathway. CONCLUSIONS: We firstly provided evidence that LHX6 exerted its anti-tumor function on BC via suppressing activation of the PI3K/Akt/mTOR signaling, which eventually inhibited the progression of BC.
OBJECTIVE:LIM homeobox domain 6 (LHX6) is emerging as a critical regulator in carcinogenesis and tumor progression. The previous study has reported the expression and function of LHX6 in breast cancer (BC). However, its mechanism underlying BC metastasis remains largely unclear. This study aimed to investigate the related mechanisms of the tumor-suppressive role of LHX6 in BC. PATIENTS AND METHODS: Quantitative Real-time PCR (qRT-PCR) and Western blotting were used to determine LHX6 mRNA levels and protein expressions in BC tissues and cell lines. LHX6 protein expression was also analyzed in BC tissues and matched normal breast tissues using immunohistochemistry (IHC). The biologic functions of LHX6 in BC were explored by CCK-8 assay, colony formation assay, and transwell assays in vitro. Finally, we investigated the effect of LHX6 up-regulation on PI3K/AKT/mTOR pathway by Western blot. RESULTS: Our results showed that LHX6 was lowly expressed at the mRNA and protein level in BC cancer tissues and cell lines. Ectopic expression of LHX6 in MDA-MB-231 and T-47D suppressed cell growth, migration, and invasion. Mechanistically, our further investigations revealed that the upregulation of LHX6 inhibited the activation of the PI3K/Akt/mTOR signaling pathway. CONCLUSIONS: We firstly provided evidence that LHX6 exerted its anti-tumor function on BC via suppressing activation of the PI3K/Akt/mTOR signaling, which eventually inhibited the progression of BC.