The tight junction (TJ) protein claudin-4 (CLDN4) is overexpressed in bladder urothelial carcinoma (BUC) and correlates with cancer progression. However, the mechanism of CLDN4 upregulation and promotion of malignant phenotype is not clear. Here, we analyzed 157 cases of BUC and investigated the hypomethylation of CpG island in the CLDN4 promoter DNA and its correlation with cancer progression. In hypomethylated cases, CLDN4 expression, cell proliferation, stemness, and epithelial-mesenchymal transition were increased. Treatment of three human BUC cell lines with the demethylating agent aza-2′-deoxycytidine (AZA) led to excessive CLDN4 expression, and, specifically, to an increase in CLDN4 monomer that is not integrated into the TJ. The TJ-unintegrated CLDN4 was found to bind integrin β1 and increase stemness, drug resistance, and metastatic ability of the cells as well as show an anti-apoptosis effect likely via FAK phosphorylation, which reduces upon knockdown of CLDN4. Thus, CLDN4 is overexpressed in BUC by an epigenetic mechanism and the high expression enhances the malignant phenotype of BUC via increased levels of TJ-unintegrated CLDN4. CLDN4 promoter DNA methylation is expected to be a novel indicator of BUC malignant phenotype and a new therapeutic target.

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BackgroundPage kidney phenomenon is caused by strong renal parenchymal compression and leads to renal hypoperfusion and microvascular ischemia, resulting in renal dysfunction and hypertension. Although the development of Page kidney phenomenon in allograft is rare, most of its cases are induced by allograft biopsy or trauma. We observed a case of Page kidney phenomenon that was induced by unusual causes immediately after kidney transplantation.Case presentationA 66-year-old man, whose wife donated a kidney, underwent ABO-compatible living kidney transplantation. The allograft had three renal arteries that were trimmed and formed into one piece on the back table, and subsequently, it was anastomosed to the internal iliac artery. Intraoperative Doppler ultrasonography (US) revealed adequate blood flow of each renal artery. Urine output was also observed as soon as allograft blood flow was reperfused. After the surgery, the urine output decreased, and serum creatinine level increased to 6.0 mg/dL. Doppler US did not show evidence of acute rejection, ureteral obstruction, or anastomotic stenosis of the renal arteries. On postoperative day 7, surgical exploration was performed and revealed that the blood flow of each renal artery was adequate but subcapsular hematoma was detected at the upper pole of the allograft. Capsulotomy and hematoma evacuation were performed. Subsequently, urine output increased and serum creatinine level decreased up to 1.7 mg/dL. Allograft sample was obtained 1 h after the transplantation from the lower pole of the allograft. Although the cause of subcapsular bleeding was unclear in this case, a small cyst of the allograft, which might have ruptured during donor nephrectomy, was located in the middle of the hematoma, and oozing around the cyst was observed.ConclusionsOur case indicated that the small ruptured cyst of the allograft could be the cause of subcapsular hematoma and Page kidney phenomenon. Subcapsular hematoma caused by oozing over time could be difficult to diagnose using Doppler US, and thus, other imaging modalities, such as computed tomography, should be considered. Knowledge of the Page kidney phenomenon in the allograft can lead to early diagnosis and intervention, resulting in better outcomes for recipients with allograft dysfunction.

Highlight Bone is one of major metastatic site in patients with genitourinary (GU) cancer. Accurately predicting survival of patients with bone metastasis (BM) is essential. This external validation study proved high predictive accuracy of B-FOM score. B-FOM score is a simple scoring model based on five prognostic factors. B-FOM score is higher accurate tool comparing to other previously reported scores.

To investigate the organ-specific response and clinical outcomes of mixed responses (MRs) to immune checkpoint inhibitors (ICIs) for unresectable or metastatic urothelial carcinoma (ur/mUC), we retrospectively analyzed 136 patients who received pembrolizumab. The total objective response rate (ORR) and organ-specific ORR were determined for each lesion according to the Response Evaluation Criteria in Solid Tumors version 1.1 as follows: (i) complete response (CR), (ii) partial response (PR), (iii) stable disease (SD), and (iv) progressive disease (PD). Most of the organ-specific ORR was 30–40%, but bone metastasis was only 5%. There was a significant difference in overall survival (OS) between responders and non-responders with locally advanced lesions and lymph node, lung, or liver metastases (HR 9.02 (3.63–22.4) p < 0.0001; HR 3.63 (1.97–6.69), p < 0.0001; HR 2.75 (1.35–5.59), p = 0.0053; and HR 3.17 (1.00–10.0), p = 0.049, respectively). MR was defined as occurring when PD happened in one lesion plus either CR or PR occurred in another lesion simultaneously, and 12 cases were applicable. MR was significantly associated with a poorer prognosis than that of the responder group (CR or PR; HR 0.09 (0.02–0.35), p = 0.004). Patients with bone metastases benefitted less. Care may be needed to treat patients with MR as well as patients with pure PD. Further studies should be conducted in the future.