Increased Proliferation as Independent Predictor of Disease Recurrence in Initial Stage pTa Urothelial Bladder Cancer

The effect of 1,25-dihydroxyvitamin D3 on the Wnt signaling pathway in bovine intestinal epithelial cells is mediated by the DKK2 (dickkopf2) Wnt antagonist

The Wnt/β-catenin signaling pathway is aberrantly activated in most colorectal cancers. High-dose 1,25(OH)2D3 has anticancer effect by regulating Wnt signal pathway. However, it is not clear whether high-dose of 1,25(OH)2D3 have an effect on normal cells. The aim of the present study was to investigate the mechanism of high-dose 1,25(OH)2D3 on the Wnt signaling pathway in bovine intestinal epithelial cells. The potential mechanism of action was investigated after knockdown and overexpression of the Wnt pathway inhibitor, DKK2, in intestinal epithelial cells by observing the effects of 1,25(OH)2D3 on proliferation, apoptosis, pluripotency and the expression of genes related to the Wnt/β-catenin signaling pathway. In the present study, we introduced the method of isolation and culture of primary bovine intestinal epithelial cells. After cells were treated with 50ng/mL 1,25(OH)2D3 or DMSO for 48h, total RNA was extracted, and six differentially expressed genes, including SERPINF1, SFRP2, SFRP4, FZD2, WISP1 and DKK2 were identified by transcriptome sequencing, which were related to Wnt signaling pathway. To further explore the mechanism of 1,25(OH)2D3 on the Wnt/β-catenin signaling pathway, we constructed knockdown and overexpression plasmids of DKK2. After transfecting these plasmids into bovine intestinal epithelial cells, we measured the expression of DKK2 mRNA and protein through GFP expression, qRT-PCR and western blot analyses to verify the transfection efficiency. In addition, the CCK-8 assay was used to detect the cell proliferation rate after transfection. Subsequently, the transfected cells were treated with 1,25(OH)2D3 for 48h, and the proliferation- (Ki67 and PCNA), apoptosis- (Bcl-2, p53, casp3 and casp8), pluripotency- (Bmi-1, Lrig1, KRT19 and TUFT1) and Wnt/ β-catenin signaling pathway- related genes (LGR5, DKK2, VDR, β- Catenin, SFRP2, WISP1 and FZD2) were detected by qRT-PCR and western blot analyses. Our results showed that the expression trend of some genes in bovine intestinal epithelial cells under high-dose 1,25(OH)2D3 was consistent with the sequencing results, including SFRP2 (P<0.001), SFRP4 (P<0.05), FZD2 (P<0.01), WISP1 (P<0.001) and DKK2 (P<0.001). In addition, knockdown of DKK2 inhibited cell proliferation (P<0.01), but DKK2 overexpression promoted cell proliferation (P<0.01). Compared to the control group, 1,25(OH)2D3 promoted the expression of Wnt/β-catenin signaling pathway-related proteins in bovine intestinal epithelium, thus maintaining intestinal homeostasis in normal intestinal epithelium. In addition, knockdown and overexpression of DKK2 indicated that 1,25(OH)2D3 weakened the inhibitory effect of DKK2 on the Wnt/β-catenin signaling pathway. Together, these results suggest that high-dose 1,25(OH)2D3 has no killing effect on normal intestinal epithelial cells and regulates Wnt/β-catenin signaling pathway through DKK2.

Urine and Serum Exosomes as Novel Biomarkers in Detection of Bladder Cancer

Background:

The gold standard for initial clinical diagnosis of bladder cancer involves cystoscopic examination of bladder and histological evaluation of tissues. There is a critical need to identify non-invasive and sensitive biomarkers. Early detection is essential challenge in diagnosis and surveillance of bladder carcinoma. Exosomes are nano- sized vesicles present in many biological fluids and have significant role in cancer. Thus, quantification of exosomes in different stages of bladder cancer may be of critical concern for clinical diagnosis and prognosis.

Methods:

Tumor derived exosomes levels in urine and serum samples of 70 bladder cancer Egyptian patients from stages T0-T3 and 12 healthy control people were measured using ELISA technique.

Results:

When compared to health subjects, exosomes levels in bladder cancer patients were increased in urine and serum samples at different stages of the disease. A gradual increase in tumor derived exosomes in serum (1.21, 3.31, 4.71, 6.47µg/ml) and urine (1.59, 2.84, 4.75, 6.67µg/ml) was observed comparative to invasiveness of tumor (T0-T3). Serum was more specific (100%) sample for detection of exosomes in bladder cancer.

Conclusion:

our findings suggest that tumor derived exosomes may offer a convenient tool for early diagnosis and monitoring of bladder cancer.