Aberrant microRNA (miRNA) expression has been investigated in gastric cancer, which is one of the most common malignancies. However, the roles of miRNAs in gastric cancer remain largely unknown. In the present study, we found that microRNA-372 (miR-372) directly targets tumor necrosis factor, α-induced protein 1 (TNFAIP1), and is involved in the regulation of the NFκB signaling pathway. Furthermore, overexpression of TNFAIP1 induced changes in AGS cells similar to those in AGS cells treated with miR-372-ASO. Collectively, these findings demonstrate an oncogenic role for miR-372 in controlling cell growth and apoptosis through downregulation of TNFAIP1. This novel molecular basis provides new insights into the etiology of gastric cancer.

The role of microRNAs (miRNAs) in regulating gene expression is currently an area of intense interest. Previous studies have shown that miRNA-372 plays crucial roles in gastric tumorigenesis by targeting the mRNA of tumor necrosis factor, α-induced protein 1 (TNFAIP1). The present study showed that miR-373 is upregulated in gastric adenocarcinoma tissue and gastric carcinoma cell lines when compared to normal gastric tissues. The overexpression of miR-373 in the gastric cancer cells increased cell proliferation. A bioinformatics search revealed a conserved target site within the 3′ untranslated region (UTR) of TNFAIP1, an immediate-early response gene of the endothelium induced by TNF-α. The overexpression of miR-373 caused the suppression of a luciferase reporter containing the TNFAIP1 3′UTR in the HEK293 cells and reduced the levels of TNFAIP1 protein in the AGS cells. The mRNA levels of TNFAIP1 in the gastric cancer and normal gastric tissues were negatively correlated with the expression levels of miR-373 in these tissues. Moreover, the knockdown of TNFAIP1 had a similar effect to the overexpression of miR-373. The overexpression of TNFAIP1 may partly rescue the inhibition of proliferation caused by the inhibitor, miR-373-ASO. Taken together, these findings demonstrate an oncogenic role for miR-373, similar to that of miR-372, in controlling cell growth through the downregulation of TNFAIP1.

Caudatin, a C-21 steroidal glyco-side isolated from Chinese herbs, has a long history of use for the treatment of multiple diseases, including cancers. However, the precise mechanisms of actions of caudatin in human uterine cancer cells remain unclear. In this study, we investigated the molecular mechanisms by which caudatin inhibits cell growth in human cervical carcinoma cell line (HeLa) and endometrial carcinoma cell line (HEC-1A). Treatment with caudatin promoted cell morphology change, inhibited cell proliferation, colony formation, migration and spheroid formation, and induced cell apoptosis. Our results showed that the expression of tumor necrosis factor; α-induced protein 1 (TNFAIP1) was downregulated in uterine cancer cells and tissues compared to paired adjacent non-tumor uterine tissues. Further molecular mechanism study showed that caudatin can directly regulate TNFAIP1 expression in a concentration-dependent manner and also associated with the downregulation of NF-κB and upregulation of BAX/BcL-2 ratio and caspase-3. Moreover, we found that overexpression of TNFAIP1 inhibits the growth and invasion, and induces apoptosis in uterine cancer cells through inhibition of the NF-κB pathway, suggesting that TNFAIP1 may act as a potential therapeutic target for the treatment of cancer. We found that caudatin inhibited tumorigenicity and upregulated TNFAIP1 in vivo. Taken together, caudatin impacts on cell proliferation, migration and apoptosis of uterine cancer cells by regulating several carcinogenesis-related processes, including a novel mechanism involving the targeting of TNFAIP1/NF-κB signaling. Our findings provide new insights into understanding the anticancer mechanisms of caudatin in human uterine cancer therapy.

Prostate cancer is a serious disease that can invade bone tissues. These bone metastases can greatly decrease a patient’s quality of life, pose a financial burden, and even result in death. In recent years, tumor cell-secreted microvesicles have been identified and proposed to be a key factor in cell interaction. However, the impact of cancer-derived exosomes on bone cells remains unclear. Herein, we isolated exosomes from prostate cancer cell line PC-3 and investigated their effects on human osteoclast differentiation by tartrate-resistant acid phosphatase (TRAP) staining. The potential mechanism was evaluated by qRT-PCR, western blotting, and microRNA transfection experiments. The results showed that PC-3-derived exosomes dramatically inhibited osteoclast differentiation. Marker genes of mature osteoclasts, including CTSK, NFATc1, ACP5, and miR-214, were all downregulated in the presence of PC-3 exosomes. Furthermore, transfection experiments showed that miR-214 downregulation severely impaired osteoclast differentiation, whereas overexpression of miR-214 promoted differentiation. Furthermore, we demonstrated that PC-3-derived exosomes block the NF-κB signaling pathway. Our study suggested that PC-3-derived exosomes inhibit osteoclast differentiation by downregulating miR-214 and blocking the NF-κB signaling pathway. Therefore, elevating miR-214 levels in the bone metastatic site may attenuate the invasion of prostate cancer.