GRHL3 Promotes Tumor Growth and Metastasis via the MEK Pathway in Colorectal Cancer

GRHL3 is a factor associated with a tumor, of which the molecular mechanism remains a further investigation. We explored the underlying mechanism of tumor-promoting effect of GRHL3 in colorectal cancer (CRC), which is involved in the MEK1/2 pathway. The expression of GRHL3 was measured in CRC and adjacent normal tissue using qPCR and immunohistochemical staining. Lentivirus-mediated knockdown expression of GRHL3 was performed in the CRC cell line HT29. Cell proliferation and metastasis were assayed in vitro, and tumorigenicity was investigated in vivo. We found higher GRHL3 expression in colorectal cancer, which was negatively correlated with patients’ prognosis. Results from studies in vitro and in vivo indicated that downregulation of GRHL3 expression inhibited tumor growth and metastasis and inhibited the activation of the MEK1/2 pathway. The effect of GRHL3 downexpression was the same as that of MEK1/2 antagonists on suppression of tumor growth and metastasis. Our results suggested that GRHL3 may act as an oncogene to promote tumor growth and metastasis via the MEK pathway in colorectal cancer.

HES5 Activates Long Noncoding RNA UCA1 to Induce Colorectal Cancer Progression by Modulating miR-185/NOTCH3 Signaling

Colorectal cancer (CRC) is one of the most common diagnosed cancers around the world. The poor prognosis and high fatality caused by metastasis are still the challenges for clinical treatment. Therefore, it is promising to clarify the detailed molecular mechanism of CRC metastasis. Accumulating evidences indicate that long noncoding RNAs (lncRNAs) play important roles in cancer progression including CRC. In this study, the function of lncRNA UCA1 was investigated. UCA1 was confirmed to be highly expressed in colorectal cancer. Moreover, the UCA1 expression level was positively related to tumor stages. Silencing UCA1 showed inhibitory effect on cell proliferation and metastasis. Both UCA1 and NOTCH3 were validated as direct targets of miR-185. Silencing UCA1 repressed NOTCH3 expression through the miR-185 sponge. NOTCH3 was found to be highly expressed in CRC patients and positively related to UCA1 expression. Furthermore, HES5 was verified as a transcription factor of UCA1, which induced UCA1 expression. In conclusion, UCA1 is a direct target of HES5. UCA1 promotes CRC metastasis through regulating the miR-185/NOTCH3 axis.