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Objective: There is a great interest in determining whether the expression of the programmed cell death ligand 1 is correlated with the efficacy of immune checkpoint inhibitors in patients with clear cell renal cell carcinoma; however, primary tumor biopsies can only provide limited information. Therefore, we explored the expression of programmed cell death ligand 1 on circulating tumor cells, which is a potential predictor of therapeutic response., Methods: Circulating tumor cells were isolated from 20 clear cell renal cell carcinoma patients based on cell surface markers targeting clear cell renal cell carcinoma using IsoFlux device, followed by identification according to cell morphology and immunofluorescence studies. Programmed cell death ligand 1 expression status and clinical correlations were also analyzed., Results: Before treatment with programmed cell death protein 1 inhibitors, circulating tumor cells were detected in all patients, ranging from 1 to 22 (median 7), with 75% (15/20) of the patients having programmed cell death ligand 1 + circulating tumor cells. Circulating tumor cell programmed cell death ligand 1 expression did not correlate with the immunohistochemical staining of programmed cell death ligand 1 in primary tumors. During treatment with programmed cell death protein 1 inhibitors, the disease control rate was much higher in the patients harboring programmed cell death ligand 1 + circulating tumor cells (73%, 11/15) than others (20%, 1/5). We also found that changes in total circulating tumor cell numbers and programmed cell death ligand 1 + circulating tumor cell counts correlated well with the disease outcome., Conclusion: We showed that the presence of programmed cell death ligand 1 + circulating tumor cells before programmed cell death protein 1 inhibition treatment could be a prognosis predictive factor and that the dynamic changes in circulating tumor cell numbers may be used to monitor the therapeutic response. Our study confirms the possibility of programmed cell death ligand 1 + circulating tumor cell detection in clear cell renal cell carcinoma patients' blood samples, which can potentially be used as an individualized immunotherapy molecular biomarker for real-time exploration., (© 2022 The Japanese Urological Association.)

Within the tumour microenvironment, a complex network of chemokines and their receptors affects the initiation and progression of tumours. The higher levels of tumour necrosis factor-alpha (TNF-α) are associated with tumour progression and an anti-TNF-α monoclonal antibody has been used successfully to treat patients with renal cell carcinoma (RCC). However, the role of chemokines and their receptors in the TNF-α-promoted progression of RCC remains unclear. In this study, TNF-α was found to enhance the migration, invasion and epithelial-mesenchymal transition (EMT) of RCC cells. To further investigate the molecular mechanism of TNF-α on the progression of RCC, reverse transcription and quantitative PCR was used to screen chemokines and chemokine receptors that were associated with tumorigenesis. The results showed that TNF-α significantly increased the expressions of CXCR2 and CXCR3 and their related ligands in RCC cells. Subsequently, we used a lentiviral shRNA system to knockdown the expression of CXCR2 and/or CXCR3 in RCC cells. CXCR2 and CXCR3 silencing inhibited the induction of Slug and ZEB-1 with TNF-α treatment of RCC cells. In addition, the knockdown of both CXCR2 and CXCR3 resulted in a greater decrease in cell migration, invasion and clonogenic ability compared with either CXCR2 or CXCR3 knockdown alone. Moreover, CXCR2 and CXCR3 silencing significantly reduced the sphere-forming ability of RCC cells. High expression levels of CXCR2 and CXCR3 in cancer tissues correlated with tumour progression of renal cell carcinoma. These findings suggest that TNF-α augments CXCR2 and CXCR3 to promote the progression of renal cell carcinoma leading to a poor prognosis., (© 2016 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.)

Background: It has been proposed that 17-β-estradiol (E2) activates estrogen receptor and inhibits renal cell carcinoma (RCC) growth. In the present study we explored the role of E2 and ER in the regulation of RCC growth., Materials and Methods: The RCC cell line ACHN was treated by E2 combining with E2 antagonist Fulvestrant or ER knockdown, and cell growth was monitored. Quantitative phosphoproteomics was applied to study the E2 regulated non-genomic phosphorylation changes. Western blotting, immunofluorescence microscopy, and apoptosis assays were used for validation., Results: E2 induced ER-dependent growth inhibition in RCC cell lines. Quantitative phosphoproteomics revealed that E2 induced both apoptosis and autophagy. Cellular apoptosis was confirmed by altered mitochondrial membrane potential, and ER-dependent autophagosome formation was also found., Conclusion: Our data revealed the potential dual roles of E2 in regulating RCC growth via autophagy and apoptosis pathways., (Copyright© 2016, International Institute of Anticancer Research (Dr. John G. Delinasios), All rights reserved.)

Mitochondria are the powerhouses of cells. Mitochondrial C-Raf is a potential cancer therapeutic target, as it regulates mitochondrial function and is localized to the mitochondria by its N-terminal domain. However, Raf inhibitor monotherapy can induce S338 phosphorylation of C-Raf (pC-Raf(S338)) and impede therapy. This study identified the interaction of C-Raf with S308 phosphorylated DAPK (pDAPK(S308)), which together became colocalized in the mitochondria to facilitate mitochondrial remodeling. Combined use of the Raf inhibitors sorafenib and GW5074 had synergistic anticancer effects in vitro and in vivo, but targeted mitochondrial function, rather than the canonical Raf signaling pathway. C-Raf depletion in knockout MEF(C-Raf-/-) or siRNA knockdown ACHN renal cancer cells abrogated the cytotoxicity of combination therapy. Crystal structure simulation showed that GW5074 bound to C-Raf and induced a C-Raf conformational change that enhanced sorafenib-binding affinity. In the presence of pDAPK(S308), this drug-target interaction compromised the mitochondrial targeting effect of the N-terminal domain of C-Raf, which induced two-hit damages to cancer cells. First, combination therapy facilitated pC-Raf(S338) and pDAPK(S308) translocation from mitochondria to cytoplasm, leading to mitochondrial dysfunction and reactive oxygen species (ROS) generation. Second, ROS facilitated PP2A-mediated dephosphorylation of pDAPK(S308) to DAPK. PP2A then dissociated from the C-Raf-DAPK complex and induced profound cancer cell death. Increased pDAPK(S308) modification was also observed in renal cancer tissues, which correlated with poor disease-free survival and poor overall survival in renal cancer patients. Besides mediating the anticancer effect, pDAPK(S308) may serve as a predictive biomarker for Raf inhibitors combination therapy, suggesting an ideal preclinical model that is worthy of clinical translation., (©2015 American Association for Cancer Research.)

Background: Angiomyolipomas are benign tumors of the kidney. Typical angiomyolipomas are usually recognized by identifying fat components before any intervention. On the contrary, solid renal masses without evident fatty components but containing calcifications on the computed tomography scan are suspicious for malignancy. However, as in this rare case, rules of diagnostic imaging are of exceptions., Case Presentation: A 40-year-old man presented with left flank pain. The plain X-ray showed multiple coarse calcifications of 4.0x3.2 cm in diameter on the left upper quadrant abdomen. Computed tomography scan further revealed a solid renal mass and inside the mass there were calcifications. The size of the tumor was 5.6×5.5×6.3 cm. We performed a radical nephrectomy, and the histopathology showed a minimally fat-contained angiomyolipoma of multiple calcifications. The patient was free of recurrence or metastases after a follow-up period of 3 years., Conclusion: An angiomyolipoma containing calcification is rare. An angiomyolipoma with minimal fat concomitant with calcifications is an even rarer presentation. It is very difficult to differentiate a minimal-fat angiomyolipoma with calcifications from a renal cell carcinoma preoperatively. In such a circumstance, a well-planned partial nephrectomy may be optimal for the patient, regardless of the tumor size.

Chronic low dose of tumor necrosis factor-α (TNF-α) stimulation promotes tumorigenesis by facilitating tumor proliferation and metastasis. The plasma levels of TNF-α are increased in patients with renal cell carcinoma (RCC). Furthermore, high-grade clear cell RCC cell lines secrete more TNF-α than low-grade ones, and allow low-grade cell lines' gain of invasive ability. However, the molecular mechanism of TNF-α in mediating progression of RCC cells remains unclear. In the present study, TNF-α induced epithelial-mesenchymal transition (EMT) of RCC cells by repressing E-cadherin, promoting invasiveness and activating matrix metalloproteinase (MMP) 9 activity. RCC cells underwent promoted growth in vivo following stimulation with TNF-α. In addition, TNF-α induced phosphorylation of extracellular signal-regulated kinase, nuclear factor kappa B (NF-κB) and Akt in a time-dependent manner, and increased nuclear translocation and promoter activity of NF-κB. To investigate the role of NF-κB activation in TNF-α-induced EMT of RCC, we employed chemical inhibitors (NF-κB activation inhibitor and Bay 11-7082) and transfected dominant-negative (pCMV-IκBαM) and overexpressive (pFLAG-p65) vectors of NF-κB. While overexpression of NF-κB p65 alone could induce E-cadherin loss in RCC, EMT phenotypes and MMP9 expressions induced by TNF-α were not reversed by the inhibitors of NF-κB activation. These results suggest that the TNF-α signaling pathway is involved in the tumorigenesis of RCC. However, NF-κB activation is not crucial for invasion and EMT enhanced by TNF-α in RCC cells.

Ipsilateral multiple synchronous primary renal neoplasms is an uncommon presentation, and only a few cases have been reported in published studies. We report the case of a 57-year-old woman with acute pyelonephritis as the initial presentation, in whom conservative treatment had no effect. Surgical intervention revealed the presence of concomitant renal cell carcinoma, collecting duct carcinoma, and urothelial carcinoma (transitional cell carcinoma) of the kidney. Metastatic renal cell carcinoma to the bladder, liver, and lung subsequently developed. Deceptive inflammatory presentations can occur in aggressive synchronous renal malignancies. Recognition of this rare disease entity could prevent delays in diagnosis and treatment.

Purpose: This study is aimed at investigating antineoplastic efficacy of histone deacetylase inhibitor (HDACI) LBH589 on renal cell carcinoma (RCC) and elucidating the novel molecular mechanisms involved in growth arrest and apoptosis by targeting the important nonhistone molecules., Experimental Design: We analyzed the growth-inhibitory effect of LBH589 on RCC by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay in vitro and antitumor efficacy by xenograft experiments in vivo. To verify the associated molecular mechanisms involved in LBH589-mediated cell death and cell cycle progression by Western blotting and fluorescence-activated cell sorting analysis., Results: HDACI LBH589 induced degradation of both Aurora A and B kinases through a proteasome-mediated pathway by targeting HDAC3 and HDAC6. The dual degradation of Aurora A and B kinases mediated by LBH589 resulted in inducing G2-M arrest and apoptosis of renal cancer cell lines and our results also showed that LBH589 potently inhibited renal cancer cell growth in vitro and suppressed tumor formation in vivo. The Aurora A and B kinases and HDAC3 are overexpressed in the human RCC tumor tissues examined, which make them perfect targets for HDACI LBH589 treatment., Conclusions: Our in vitro and in vivo data showed that LBH589 has potent anticancer effect of renal cancer cells. LBH589 and other HDACI treatment resulted in inducing G2-M arrest and apoptosis of renal cancer cells through degradation of Aurora A and B kinases by inhibition of HDAC3 and HDAC6. The clinical efficacy of LBH589 in the treatment of patients with metastatic RCC, especially those with high Aurora kinase and HDAC expression, is worthy of further investigation.

Background and Purpose: The expression of specific CD44 isoforms is associated with metastasis and poor prognosis in human malignant tumors. We retrospectively investigated the expression of the CD44 variant isoform v5 (CD44v5) in human renal cell carcinoma (RCC) specimens by immunohistochemistry., Methods: We studied the expression of CD44v5 immunohistochemistry in archival tissue specimens from 72 RCC patients (47 men and 25 women) with a mean age of 60.1 years (range, 30 to 83 years) who underwent resection in our hospital from 1986 to 1996. The patients were divided into non-invasive (pT1, pT2, and pT3a; n = 49) and invasive groups (pT3b, pT3c, and any T with N+; n = 23). Among the 72 patients, 67 were followed for at least 60 months (up to 190 months) after radical nephrectomy. Twenty nine renal specimens, including 15 of normal renal parenchyma and 14 of inflammatory or immune renal diseases, were used as controls., Results: All control group tissues expressed CD44v5. CD44v5 expression was detected in 66 of 72 RCC specimens (91.7%). In general, the expression of CD44v5 was higher in the non-invasive group [47/49 (95.9%) vs 19/23 (82.6%), p < 0.05]. Five cases were lost to follow-up. Thirty three of 67 patients (49.3%) died of RCC-related causes during the follow-up period. The CD44v5 non-expression group had a higher mortality rate than the expression group [4/5 (80%) vs 29/62 (46.8%), p < 0.001]. The 5-year and 10-year survival rates were significantly higher in patients with CD44v5 expression than in those without (p < 0.001)., Conclusions: This study found that CD44v5 expression was greater in early stage than in advanced stage RCC and was associated with tumor progression and long-term survival. Although the survival analysis showed both tumor stage and CD44v5 expression were significant prognostic factors in RCC, only tumor stage remained an independent factor.