RING domain of zinc finger protein like 1 is essential for cell proliferation in endometrial cancer cell line RL95-2

ANP reduced Hedgehog signaling-mediated activation of matrix metalloproteinase-9 in gastric cancer cell line MGC-803

OBJECTIVE

Gastric cancer is the most common malignant tumor. Most patients suffering from gastric cancer die of metastasis. The role of Atrial natriuretic peptide (ANP) in inhibiting and eliminating kinds of cancer cells has been reported. Aberrant activation of Hedgehog (Hh) signaling pathway contributes to initiation and progression of various malignancies. We have previously reported that the inhibitor of Hh, cyclopamine, reduces the metastatic activity of MGC-803 via inhibiting the expression of matrix metalloproteinases (MMP)-9. It remains to be further demonstrated that ANP has the suppressive effects on invasion and metastasis in gastric cancer via Hh-mediated MMP-9 production.

METHODS

Transwell, western blot, qRT-PCR were used after application of ANP on MGC-803 gastric cancer cells to determine the levels of cell migration and invasion, protein levels of MMP-9 and Hh, as well as mRNAs of MMP-9 and Hh, respectively.

RESULTS

It was demonstrated that the migration and invasion were significantly lower, MMP-9 and Hh as well as their mRNAs were lower as well, in ANP-treated MGC-803 gastric cancer cells than those in control.

CONCLUSIONS

The expression of MMP-9 induced by aberrant activation of Hh in MGC-803 was inhibited by ANP, which may contribute to the inhibition of cell migration and invasion. These results suggested the potential of ANP to be used in gastric cancer therapy as an inhibitor targetting Hh signaling pathway to inhibit the proliferation as well as invasion and metastasis of gastric cancer.

Knockdown of Trop2 inhibits proliferation and migration and induces apoptosis of endometrial cancer cells via AKT/β-catenin pathway

Endometrial cancer (EC) is the most common gynaecologic malignancy in western countries and has been reported to account for about 7% of female malignant tumours and 20% to 30% of female genital system malignant tumours. Accumulating evidence showed the expression of human trophoblast cell surface antigen 2 (Trop2) was abnormal in many cancers; however, the expression and role of Trop2 in EC are not clear. The Trop-2 protein expression was detected by western blot in EC cells. Cell proliferation, apoptosis, and migration were measured by CCK-8, flow cytometry, and Transwell assay, respectively. The epithelial mesenchymal transition (EMT) and AKT/β-catenin signalling pathway-related proteins in EC cell lines were detected by western blot assay following Trop2 gene silencing. The present study revealed that the Trop2 protein was highly expressed in EC cell lines compared with human endometrial epithelial cells. The Trop2 mRNA and protein were obviously decreased following transfection with Trop2-siRNA sequence in KLE and Ishikawa cells. Meanwhile, Trop2 gene silencing in KLE and Ishikawa cells strongly inhibited cell proliferation and migration and increased cell apoptosis. Investigation into the molecular mechanism indicated that the Trop2 gene silencing suppressed EMT and AKT/β-catenin signalling pathway activation. SIGNIFICANCE OF THE STUDY: These findings suggested that Trop2 silencing inhibited EC cell proliferation and migration and promoted cell apoptosis. The mechanism might be related to the inhibition of the AKT/β-catenin signalling pathway in EC cells. Therefore, Trop2 may be a potential therapeutic target for the treatment of EC.