Intravesical administration of exogenous microRNA-145 as a therapy for mouse orthotopic human bladder cancer xenograft

We previously reported that the level of microRNA (miR)-145 is attenuated in human bladder cancer cells. In this current study, we investigated whether intravesical administration of miR-145 could be a potential therapeutic strategy for controlling bladder cancer by using an orthotopic human bladder cancer xenograft model. Following transfection of 253J B-V cells with miR-145, the effects of the ectopic expression of miR-145 were examined by performing MTT, Western blotting analysis, Hoechst33342 staining, and wound healing assay in vitro. Also, a mouse orthotopic human bladder cancer model was established by inoculating 253J B-V cells into the bladder wall of mice. The anti-cancer effects of intravesical injections of miR-145 into these mice were then assessed. Transfection of 253J B-V cells with miR-145 induced apoptosis and suppression of cell migration in vitro. Western blotting showed that the levels of c-Myc, socs7, FSCN1, E-cadherin, β-catenin, and catenin δ-1 were decreased and that the PI3K/Akt and Erk1/2 signaling pathways were increased in compensatory fashion. In vivo, mice treated with miR-145 showed 76% inhibition of tumor growth, with a significant prolongation of animal survival (p = 0.0183 vs. control). Western blotting showed that both apoptosis and cell motility-related genes were significantly decreased as seen in vitro. Furthermore, PI3k/Akt and Erk1/2 signaling pathways, which were activated in a compensatory manner in vitro, were decreased in vivo. Intravesical administration of exogenous miR-145 was thus concluded to be a valid therapy for bladder cancer in this human bladder cancer xenograft model.     

Organic cation transporter 2 for predicting cisplatin-based neoadjuvant chemotherapy response in gastric cancer

Some studies have shown the usability of neoadjuvant chemotherapy (NAC) in gastric cancer (GC). Nevertheless there are a few predictive markers of the effectiveness of NAC in GC. The aim of this study is to assess the predictive impact of organic cation transporter 2 (OCT2) expression on response to neoadjuvant chemotherapy (NAC) in gastric cancer. We retrospectively assessed 66 patients with advanced gastric cancer received NAC with S-1/cisplatin or paclitaxel/cisplatin. Expression levels of OCT2 were assessed by immunohistochemistry in pre-chemotherapy biopsies and correlated with clinicopathologic parameters including pathologic response. High expression level of OCT2 (OCT2^high) was significantly associated with intestinal type according to Laurén classification (P = 0.03) and low histologic grade (P = 0.03). In univariate analysis of the entire cohort, no variables showed any significant association with a response, although intestinal type (P = 0.09), low histologic grade (P = 0.09), and OCT2^high (P = 0.07) tended to be more frequent in responders compared with non-responders. When the two treatment groups were separately assessed in the univariate analysis, a significantly higher rate of OCT2^high was observed in responders compared with non-responders in the S-1/cisplatin group (P = 0.001). In addition, multivariate analysis identified OCT2^high as the sole independent predictor of response (P = 0.04). However, in the paclitaxel/cisplatin group, no variables were associated with response. Taken together, our results suggest that OCT2^high may represent a potential predictor of response to NAC with S-1/cisplatin in gastric cancer.     

Expression of DDX27 contributes to colony-forming ability of gastric cancer cells and correlates with poor prognosis in gastric cancer

Previously, we have reported that gain at chromosome 20q13 is the most common genomic copy number aberration in gastric cancer (GC) (29/30 cases), and that among the genes located in this region, we have identified DDX27, whose expression level shows the highest correlation with genomic copy number, as a candidate therapeutic target for GC. Here, we analyzed the clinicopathological significance of DDX27 using immunohistochemistry and studied its functions using knockdown assays. We found that DDX27 was frequently upregulated in GC tissues (98 of 140 cases, 70%), and significantly associated with venous invasion and liver metastasis. Furthermore, multivariate analysis of GC patients showed that high expression of DDX27 was independently associated with poorer prognosis. In functional assays, knockdown of DDX27 reduced the ability of GC cells to form colonies both on conventional plates and soft agar, but had little effect on their invasiveness. We also found that knockdown of DDX27 reduced the viability of GC cells through inhibition of cell cycle progression independently of apoptosis. Interestingly, DDX27 depletion induced accumulation of TP53 in a TP53 wild-type cell line, AGS, but not in a TP53-deleted cell line, 44As3, although DDX27 knockdown commonly reduced the viability of both, indicating the TP53-dependent and independent cell cycle control of DDX27. Thus, our results suggest that expression of DDX27 contributes to colony formation by GC cells through cell cycle control and may be a potential therapeutic target for GC patients with chromosome gain at 20q13.