Value of computer‐assisted quantitative nuclear morphometry for differentiation of reactive renal tubular cells from low‐grade urothelial carcinoma

H. Ohsaki, E. Hirakawa, K. Kagawa, M. Nakamura, H. Kiyomoto and R. Haba Value of computer‐assisted quantitative nuclear morphometry for differentiation of reactive renal tubular cells from low‐grade urothelial carcinoma Objective: To assess whether computer‐assisted quantitative morphological parameters can be an effective tool for objectively distinguishing reactive renal tubular cells from low‐grade urothelial carcinoma cells (LG‐UCs) in voided urine. Methods: Nuclear morphometry was performed by a computer‐assisted image analyser system on Papanicolaou‐stained cytological specimens. The circumference of reactive renal tubular cells (n = 40) or LG‐UC (n = 20) nuclei were manually traced, and the following nuclear morphometric parameters were analysed: (i) area, (ii) perimeter, (iii) roundness factor, (iv) maximum length, and (v) linear factor. For each nuclear measurement, we calculated the maximum, minimum, mean and standard deviation. Results: The mean nuclear area and nuclear perimeter were higher in reactive renal tubular cells compared to the LG‐UCs. The mean of roundness and linear factors (reflecting a tendency for the nuclear outline to be regular and oval, respectively) were higher in LG‐UCs compared with reactive renal tubular cells. Among nuclear areas, the nuclear perimeter, roundness factors and maximum length did not show any significant differences between reactive renal tubular cells and LG‐UCs. On the other hand, the linear factor showed a mean higher value among LG‐UCs than reactive renal tubular cells (P = 0.023). Conclusions: Of five quantitative nuclear morphological parameters, only linear factor was statistically significant in differentiating reactive renal tubular cells in renal disease from LG‐UCs.     

Expression of vimentin and high‐molecular‐weight cytokeratin (clone 34ßE12) in differentiating reactive renal tubular cells from low‐grade urothelial carcinoma cells in voided urine

H. Ohsaki, E. Hirakawa, M. Nakamura, Y. Norimatsu, H. Kiyomoto and R. Haba Expression of vimentin and high‐molecular‐weight cytokeratin (clone 34ßE12) in differentiating reactive renal tubular cells from low‐grade urothelial carcinoma cells in voided urine Objective: Reactive renal tubular cells show features of an atypical repair reaction. Differentiation between reactive renal tubular cells and low‐grade urothelial carcinoma (LG‐UC) cells can therefore be a diagnostic challenge based on morphology alone. In this study, we evaluated the diagnostic utility of vimentin and a high‐molecular‐weight cytokeratin antibody (clone 34ßE12) in differentiating reactive renal tubular cells from LG‐UC. Methods: We evaluated voided urine cytology and surgical specimens from 40 patients with renal disease, and 17 patients with LG‐UC. All slides were stained with vimentin and 34ßE12. Results: In the reactive renal tubular cells in voided urine cytology, vimentin showed strong cytoplasmic staining in 39/40 (97.5%) cases, but all were negative for 34ßE12. LG‐UC cells showed positive staining for 34ßE12 in 3/17 (17.6%) cases, whereas none were positivity for vimentin. The reactive renal tubular cells of histological specimens in the renal disease group demonstrated positive for vimentin in all 40 cases and all were negative for 34ßE12. The LG‐UC group showed abnormal staining for 34ßE12 in 4/17 (23.5%) cases, whereas none were positive for vimentin. Conclusions: Vimentin expression in urine cytology can help to distinguish reactive renal tubular cells from LG‐UC. However, 34ßE12 does not appear to be a useful adjunct to distinguish these two groups in voided urine cytology.     

Can cytological features differentiate reactive renal tubular cells from low‐grade urothelial carcinoma cells?

H. Ohsaki, E. Hirakawa, Y. Kushida, S. Yokoshita, M. Nakamura, H. Kiyomoto and R. Haba Can cytological features differentiate reactive renal tubular cells from low‐grade urothelial carcinoma cells? Objective: To compare the cytomorphological and immunocytochemical features of reactive renal tubular cells and low‐grade urothelial carcinoma cells (LG‐UCs). Methods: We examined 15 cytological parameters in 38 cases with reactive renal tubular cells in renal disease and 20 cases of LG‐UCs from bladder cancer that had been diagnosed by histological examination. Voided urine cytological parameters evaluated were as follows: (i) maximum cell numbers of clusters, (ii) cannibalism, (iii) rosette‐like arrangement, (iv) hobnail‐shaped cells, (v) vacuolated cytoplasm, (vi) intracytoplasmic haemosiderin, (vii) irregular nuclear contours, (viii) chromatin pattern, (ix) prominent nucleoli, (x) cast encasement, (xi) casts, (xii) dysmorphic erythrocytes, (xiii) isomorphic erythrocytes, (xiv) necrosis, and (xv) vimentin reactivity. The above parameters were determined using Mann–Whitney U‐test and chi‐square test, with differences considered significant at P < 0.05. Results: In reactive renal tubular cells, low to moderate cell numbers of clusters (fewer than 50 cells), rosette‐like arrangement, hobnail‐shaped cells, vacuolated cytoplasm, intracytoplasmic haemosiderin, euchromatin pattern, prominent nucleoli, dysmorphic erythrocytes and vimentin reactivity were present in significantly higher proportions compared with those in LG‐UCs. In LG‐UCs, high cell numbers of clusters (50 cells or more), cannibalism, heterochromatin pattern, isomorphic erythrocytes and necrosis were seen in significantly higher proportions. No significant differences were observed in irregular nuclear contours, cast encasement or casts. Conclusions: Based on results of the present study, maximum cell numbers of clusters, cannibalism, rosette‐like arrangement, hobnail‐shaped cells, vacuolated cytoplasm, intracytoplasmic haemosiderin, chromatin pattern, prominent nucleoli, dysmorphic erythrocytes, isomorphic erythrocytes, necrosis, and vimentin reactivity were capable of distinguishing reactive renal tubular cells from LG‐UCs.     

Nobiletin inhibits hypoxia-induced epithelial-mesenchymal transition in renal cell carcinoma cells

Hypoxia is a universal characteristic of solid tumor and involving cancer metastasis via epithelial-mesenchymal transition (EMT). Nobiletin (3′,4′,5,6,7,8-hexamethoxyflavone), a dietary polymethoxylated flavonoid found in citrus fruits, has been reported to have anticancer effects. However, the possible role of nobiletin in renal cell carcinoma (RCC) remains unclear. Thus, the aim of this study was to identify the effect of nobiletin on hypoxia-induced EMT in RCC cells. We found that nobiletin significantly inhibited the migration and invasion induced by hypoxia in RCC cells. In addition, nobiletin reversed the hypoxia-induced EMT process in RCC cells. Furthermore, nobiletin suppressed the activation of NF-κB and Wnt/β-catenin signaling pathways in hypoxia-stimulated RCC cells. In conclusion, these findings demonstrate that nobiletin inhibits hypoxia-induced EMT in human RCC cells via the inactivation of the NF-κB and Wnt/β-catenin signaling pathways.     

Establishment and characterization of a cell line (SS78) from a human renal cell carcinoma

Summary A new cell line, SS78, was established from a primary renal cell carcinoma of a Caucasian male. The tissue was dispersed with collagenase, and viable cells were separated by flotation on a Ficoll-Hypaque gradient. In culture, the SS78 cells retained a distinct epithelial morphology, and no fibroblastlike cells were seen. The cultured cells were aneuploid with a modal chromosome number of 80 and had several marker chromosomes. Inoculation of the cultured cells into athymic nude mice caused tumors at the sites of inoculation. This research was supported in part by Grants CA 15972 and CA 14930 from the National Cancer Institute through the National Bladder Cancer Project and by the Medical Research Service of the Veterans Administration.     

Knockdown of long noncoding RNA urothelial carcinoma associated 1 inhibits colorectal cancer cell proliferation and promotes apoptosis via modulating autophagy

Long noncoding RNA urothelial carcinoma associated 1 (UCA1) has been implicated in the growth and metastasis of colorectal cancer (CRC), and autophagy contributes to tumorigenesis and cancer cell survival. However, the regulatory role of UCA1 in CRC cell viability by modulating autophagy remains unclear. In the present study, a significant positive correlation was observed between UCA1 and microtubule-associated protein 1 light chain 3 (LC3) levels, and the elevated UCA1 was negatively correlated with the PKB/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway in 293T cells. Downregulation of UCA1 inhibited autophagy activation and cell proliferation, whereas the apoptosis was increased and the cell cycle was arrested in G2 stage. The next results showed that UCA1 was markedly upregulated in Caco-2 cells. Knockdown of UCA1 significantly decreased the LC3-II and autophagy-related gene 5 (ATG5) protein levels and resulted in an increase in p62 expression. Conversely, the autophagy activator rapamycin (RAPA) reversed the effects. Furthermore, downregulated UCA1 decreased Caco-2 cells population in the G1 phase and increased the cells number in G2 phage. The cell proliferation was inhibited, and apoptosis rate was promoted. More important, RAPA could also abrogate the changes induced by knockdown of UCA1. Collectively, these data demonstrated that downregulated UCA1 induced autophagy inhibition, resulting in suppressing cell proliferation and promoting apoptosis, which suggested that UCA1 might serve as a potential new oncogene to regulate CRC cells viability by modulating autophagy.     

Human renal cell carcinoma: Establishment and characterization of a new cell line (OS-RC-2)

Summary A cell line, designated as OS-RC-2, has been established from a renal cell carcinoma in a 52-yr-old Japanese male patient and maintained for 23 mo. through 60 in vitro passages. The OS-RC-2 formed monolayers of polygonal epithelial cells and lacked contact inhibition. Doubling time of cells was about 60 h at the 30th passage. Electron microscopic findings indicated numerous long microvilli on the cell surface and many glycogen granules in the cytoplasm of this cell line, which are characteristic structures of renal cell carcinoma. Chromosomal analysis revealed that a small portion of this cell line had a hypodiploid modal number of 40 and a large portion had a hypotetraploid modal number of 75. The characteristics of the karyotype were one detected marker chromosome and the translocation between the Chromosomes 2 and 13. Cell line OS-RC-2 was serially transplantable into nude mice, and histopathological findings of heterotransplanted tumor showed a close similarity to those of the original tumor. Histocompatibility antigens of OS-RC-2 were HLA-A9, Bw52, which were identical to those of the peripheral blood lymphocytes of the patient.     

Genkwadaphnin induces reactive oxygen species (ROS)-mediated apoptosis of squamous cell carcinoma (SCC) cells

Genkwadaphnin is a daphnane diterpene ester molecule isolated from the flower buds of Daphne genkwa. In the present study, we investigated the apoptosis-inducing effect of genkwadaphnin in squamous cell carcinoma (SCC) cells. Apoptosis was triggered in SCC12 cells following genkwadaphnin treatment in a time- and concentration-dependent manner. Genkwadaphnin treatment increased phosphorylation of c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK). Knockdown of JNK and p38 MAPK by recombinant adenovirus expressing microRNA (miR) resulted in significant inhibition of genkwadaphnin-induced apoptosis in SCC12 cells. Finally, pretreatment with the reactive oxygen species (ROS) scavenger N-acetylcysteine (NAC) markedly reduced SCC12 cell apoptosis, concomitant with significant inhibition of MAPK activation. These results indicate that genkwadaphnin has the potential to induce apoptosis in SCC cells, providing information on which to base further research with the aim of developing a cure for SCC.     

Human renal clear cell carcinoma: Establishment and characterization of a new cell line (G-2101)

Summary A human cell line has been established from a renal adenocarcinoma rib metastasis of a 58-y-old male. This cell line has been maintained in continuous culture for 20 mo. through more than 50 passages. It displays simulataneous expression of the intermediate filaments cytokeratin and vimentin. Flow cytometric analysis of DNA content reveals a major hyperdiploid population. This work was supported in part by a grant from Triton Biosciences, Inc.     

KIF20B promotes the progression of clear cell renal cell carcinoma by stimulating cell proliferation

Renal cell carcinoma (RCC) is a common urinary system cancer with high morbidity and mortality rate. Clear cell renal cell carcinoma (ccRCC) is a highly aggressive and common type of RCC. More and effective therapeutic targets are badly needed for the treatment of ccRCC. Kinesin family protein (KIF)20B, also named M-phase phosphoprotein 1, was reported as a microtubule-associated, plus-end-directed kinesin. KIF20B was involved in multiple cellular processes such as cytokinesis. Multiple studies indicated the oncogenic role for KIF20B in several types of tumors, including breast cancer and bladder cancer. However, the possible role of KIF20B in the progression of renal carcinoma is still unknown. Herein, our study demonstrated that KIF20B was relatively highly expressed in ccRCC tissues. In addition, KIF20B was inversely related to the clinical features including tumor size and T stage. We further found that inhibition of the KIF20B expression by a specific short hairpin RNA obviously reduces proliferation of ccRCC cells both in vitro and in vivo. Our study reveals the involvement of KIF20B in ccRCC progression. Generally, KIF20B is a promising novel therapeutic for the treatment of clear cell RCC.     

Pinin acts as a poor prognostic indicator for renal cell carcinoma by reducing apoptosis and promoting cell migration and invasion

Pinin (PNN) was originally characterized as a desmosome-associated molecule. Its function and the mechanism of its regulation in renal cell carcinoma (RCC) are still undefined. Data on PNN expression, clinicopathological features, and prognosis of patients with RCC were obtained from The Cancer Genome Atlas (TCGA) database. Immunohistochemistry revealed high PNN expression in tumour cells. PNN expression showed negative correlation with survival in patients with RCC, acting as an independent prognostic factor in RCC. PNN up-regulation might be attributed to epigenetic alterations in RCC. Immunofluorescence revealed PNN expression mainly in the nucleus of RCC cells. The transfection of siRNA targeting the PNN gene resulted in enhanced apoptosis, which was detected by flow cytometry, and reduced cell migration and invasion, which were assessed using wound healing and transwell migration assay. Gene set enrichment analysis revealed associations between PNN expression and several signalling pathways involved in cancer progression, as a potential mechanism underlying the carcinogenicity of PNN. The analyses of the Tumor Immune Estimation Resource platform showed significant positive associations between high PNN expression and tumour immune infiltrating cells. PNN may function as an oncogenic factor by reducing apoptosis and promoting cell migration and invasion in RCC.     

Identification of methylation-driven genes related to prognosis in clear-cell renal cell carcinoma

With the participation of the existing treatment methods, the prognosis of advanced clear-cell renal cell carcinoma (ccRCC) is poor. More evidence indicates the presence of methylation in ccRCC cancer cells, but there is a lack of studies on methylation-driven genes in ccRCC. We analyzed the open data of ccRCC in The Cancer Genome Atlas database to obtain ccRCC-related methylation-driven genes, and then carried out pathway enrichment, survival, and joint survival analyses. More important, we deeply explored the correlation between differential methylation sites and the expression of these driving genes. Finally, we screened 29 methylation-driven genes via MethylMix, of which six were significantly associated with the survival of ccRCC patients. This study demonstrated that the effect of hypermethylation or hypomethylation on prognosis is different, and the level of methylation of key methylation sites is associated with gene expression. We identified methylation-driven genes independently predicting prognosis in ccRCC, which offers theoretical support in bioinformatics for the study of methylation in ccRCC and a new perspective for the epigenetic study of ccRCC.     

Kinetic and growth parameters of Arthrospira (Spirulina) platensis cultivated in tubular photobioreactor under different cell circulation systems

Arthrospira platensis was cultivated in tubular photobioreactor in order to evaluate growth and biomass production at variable photosynthetic photon flux density (PPFD = 60, 120, and 240 μmol photons m(-2)s(-1)) and employing three different systems for cell circulation, specifically an airlift, a motor-driven pumping and a pressurized system. The influence of these two independents variables on the maximum cell concentration (X(m)), cell productivity (P(x)), nitrogen-to-cell conversion factor (Y(X/N) ), photosynthetic efficiency (PE), and biomass composition (total lipids and proteins), taken as responses, was evaluated by analysis of variance. The statistical analysis revealed that the best combination of responses' mean values (X(m) = 4,055 mg L(-1), P(x) = 406 mg L(-1)day(-1), Y(X/N) = 5.07 mg mg(-1), total lipids = 8.94%, total proteins = 30.3%, PE = 2.04%) was obtained at PPFD = 120 μmol photons m(-2)s(-1); therefore, this light intensity should be considered as the most well-suited for A. platensis cultivation in this photobioreactor configuration. The airlift system did not exert any significant positive statistical influence on the responses, which suggests that this traditional cell circulation system could successfully be substituted by the others tested in this work.     

Human kanadaptin and kidney anion exchanger 1 (kAE1) do not interact in transfected HEK 293 cells

Kanadaptin (k¯idney anion exchanger adaptor protein) is a widely expressed protein, shown previously to interact with the cytosolic domain of mouse Cl^?/HCO₃^? anion exchanger 1 (kAE1) but not erythroid AE1 (eAE1) by a yeast-two hybrid assay. Kanadaptin was co-localized with kAE1 in intracellular membranes but not at the plasma membrane in α-intercalated cells of rabbit kidney. It was suggested that kanadaptin is an adaptor protein or chaperone involved in targeting kAE1 to the plasma membrane. To test this hypothesis, the interaction of human kanadaptin with human kAE1 was studied in co-transfected HEK293 cells. Human kanadaptin contains 796 amino acids and was immuno-detected as a 90 kDa protein in transfected cells. Pulse-chase experiments showed that it has a half-life (t_1/2) of 7 h. Human kanadaptin was localized predominantly to the nucleus, whereas kAE1 was present intracellularly and at the plasma membrane. Trafficking of kAE1 from its site of synthesis in the endoplasmic reticulum to the plasma membrane was unaffected by co-expression of human kanadaptin. Moreover, we found that no interaction between human kanadaptin and kAE1 or eAE1 could be detected in co-transfected cells either by co-immunoprecipitation or by histidine6-tagged co-purification. Taken together, we found that human kanadaptin did not interact with kAE1 and had no effect on trafficking of kAE1 to the plasma membrane in transfected cells. Kanadaptin may not be involved in the biosynthesis and targeting of kAE1. As such, defects in kanadaptin and its interaction with kAE1 are unlikely to be involved in the pathogenesis of the inherited kidney disease, distal renal tubular acidosis (dRTA).     

Timosaponin AIII inhibits metastasis of renal carcinoma cells through suppressing cathepsin C expression by AKT/miR-129-5p axis

Timosaponin AIII (TSAIII) is a steroidal saponin that exerts anticancer activity on various cancer cells. In this study, we explore the effects of TSAIII on renal cell carcinoma (RCC) cells. Our findings show that TSAIII treatment (<8 μM) insignificantly influenced cell viability and cell cycle distribution of human RCC cell lines 786-O, A-498, and ACHN. Further observations revealed that TSAIII inhibited migration and invasion of 786-O and A-498 cells, as well as significantly decreased the production and expression of cathepsin C (CTSC) in both the cell types. Kinase cascade analysis exhibited that PI3K/AKT activation was inhibited, but PTEN expression was increased, in response to TSAIII treatments. Combining TSAIII and PI3K inhibitors, LY294002 synergically reduced the migration and invasion of 786-O and A-498 cells, as well as decreased the CTSC expression in both the cell types. We also observed that miR-129-5p bound to CTSC gene and suppressed the expression of CTSC and demonstrated that the miR-129-5p expression was synergically enhanced by TSAIII and LY294002. In addition, pretreatment with antago-miR-129-5p significantly restored the CTSC expression and the migration and invasion of TSAIII-treated 786-O cells. In conclusion, our findings reveal that TSAIII inhibits the metastatic properties of RCC cells, contributing to the inhibition of PI3K/AKT and the increase of miR-129-5p and the subsequent downregulation of CTSC. This suggests that TSAIII has significant antimetastatic activity against RCC cells and may be beneficial to RCC treatments.     

Melamine causes apoptosis of rat kidney epithelial cell line (NRK-52e cells) via excessive intracellular ROS (reactive oxygen species) and the activation of p38 MAPK pathway

There was an outbreak of urinary stones associated with consumption of melamine-tainted milk products in 2008 in China, leading to serious illness of many infants and even death. We have recently demonstrated that melamine causes oxidative damage on the NRK (normal rat kidney)-52e cells. The objective of this study was to explore the cellular signalling pathway that mediates the cell apoptosis induced by melamine in the NRK-52e cells. Fluorescence microscope showed that melamine enhanced intracellular ROS (reactive oxygen species) levels of the NRK-52e cells. AO/EB (acridine orange/ethidium bromide) staining and flow cytometry revealed that melamine increased apoptotic and necrotic percentages of the NRK-52e cells in a dose-dependent manner. Notably, MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide] assays and flow cytometry displayed that SB203580, an inhibitor for p38 MAPK (mitogen-activated protein kinase) pathway, increased the proliferation of the NRK-52e cells and reduced the apoptotic and necrotic percentages of the NRK-52e cells. Western blots further demonstrated that p38 phosphorylation was activated by melamine in the NRK-52e cells and inhibitor SB203580 blocked the increase of p38 phosphorylation induced by melamine. Together, these results suggested that melamine causes apoptosis of the NRK-52e cells via excessive intracellular ROS and the activation of p38 MAPK pathway. This study thus offers a novel insight into molecular mechanisms by which melamine has adverse cytotoxicity on renal tubular epithelial cells.