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.

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Abstract. Caudatin has been reported to trigger apoptosis in several types of cancer cell lines. In the present study, we investigated whether caudatin has therapeutic value in gastric cancer and examined the effects of caudatin on the expression of β-catenin in human gastric carcinoma cell lines. Here, we showed that caudatin treatment resulted in a dose-and time-dependent inhibition of proliferation of the gastric carcinoma cell lines. Cell cycle analysis demonstrated that caudatin induced G0/G1 arrest and downregulated CDK2 levels. In contrast, the expression of the p21 protein was increased. AGS cells treated with caudatin exhibited typical characteristics of apoptosis, which were accompanied by activation of caspase-3, -8, -9 and PARP. Western blot analysis and immunocytochemical staining showed that caudatin induced a reduction in β-catenin expression and this reduction was due to proteosome-mediated degradation. This reduction in β-catenin activation was due to the downregulation of its downstream targets cyclinD1 and c-MYC in all gastric carcinoma cell lines. Furthermore, we demonstrated that gastric adenocarcinoma tissues and AGS cells exhibited abnormal expression of miR-372. Additionally, caudatin downregulated the expression of oncomir miR-372 and miR-21, and upregulated tumor suppressor let-7a miRNA expression. These data revealed that inhibition of Wnt/β-catenin signaling is a novel mechanism of action for caudatin during therapeutic intervention in gastric cancers. IntroductionGastric cancer is one of the most common malignancies and the second leading cause of cancer-related mortality worldwide.Surgery and systemic treatment regimens in combination with radiotherapy and chemotherapy are able to cure this malignancy in the majority of cases. Unfortunately, the young age of typical gastric cancer patients further enhances the time at risk for the side effects of these therapies. Delayed toxicity and the development of secondary malignancies are a serious concern for the current anti-neoplastic armamentarium (1,2). Therefore, it is urgent to further characterize the entity of gastric tumors to better understand and predict their biological behaviors and to identify novel high efficient and low toxic therapeutic agents for the treatment of gastric cancer in clinical practice (3).Modern pharmacologic study proves that C-21 steroidal glycosides are important biological active compounds, which are widely found in the plants of the Asclepiadaceae family and exhibit extensive pharmacological effects such as inhibition of proliferation, induction of apoptosis and inhibition of the invasion of tumor cells (4,5). Caudatin, a C-21 steroidal glycoside, is mainly isolated from the root of Cynanchum bungei Decne in China. Recent studies demonstrated that caudatin induced the apoptosis of HepG2 cells or the SMMC772 cell line (6,7). Wang et al (8) found that caudatin had an inhibitory activity on the secretion of HBsAg and HBV DNA replication. Furthermore, caudatin as a prospective anti-HCC drug with the mechanism...

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