Human renal cell carcinoma: establishment and characterization of two new cell lines

Postoperative Thrombotic Microangiopathy following Radical Cystectomy for Bladder Cancer

This report describes the perioperative management of disseminated intravascular coagulation occurring abruptly during a planned cystectomy for non-metastatic bladder papillary carcinoma. Peroperatively, profuse bleeding and an acute decrease in blood pressure were effectively treated by blood transfusions and fresh frozen plasma. Haematological tests indicated the presence of disseminated intravascular coagulation. On the following three days, acute renal failure, peripheral disseminated intravascular coagulation-related thrombocytopenia and haemolytic anemia with schistocytes were suggestive of thrombotic microangiopathy. Treatment by plasma exchange along with haemodialysis was commenced. An aetiological work-up remained negative. After 21 days of treatment, haemodialysis and plasma exchange were stopped. Urological outcome was favourable. The one-year follow-up did not show any residual renal insufficiency and laboratory parameters returned to normal. In the absence of evidence in favour of an infectious, drug-related or immunological aetiology, we postulated that this thrombotic microangiopathy was caused by disseminated intravascular coagulation and that the tumour manipulation during the surgical procedure was the triggering factor.

Exogenous DKK-3/REIC inhibits Wnt/β-catenin signaling and cell proliferation in human kidney cancer KPK1

The third member of the Dickkopf family (DKK-3), also known as reduced expression in immortalized cells (REIC), is a tumor suppressor present in a variety of tumor cells. Regarding the regulation of the Wnt/β-catenin signaling pathway, exogenous DKK-1 and DKK-2 are reported to inhibit Wnt signaling by binding the associated effectors. However, whether exogenous DKK-3 inhibits Wnt signaling remains unclear. A recombinant protein of human full-length DKK-3 was used to investigate the exogenous effects of the protein in vitro in KPK1 human renal cell carcinoma cells. It was demonstrated that the expression of phosphorylated (p-)β-catenin (inactive form as the transcriptional factor) was increased in KPK1 cells treated with the exogenous DKK-3 protein. The levels of non-p-β-catenin (activated form of β-catenin) were consistently decreased. It was revealed that the expression of transcription factor (TCF) 1 and c-Myc, the downstream transcription factors of the Wnt/β-catenin signaling pathway, was inhibited following treatment with DKK-3. A cancer cell viability assay confirmed the anti-proliferative effects of exogenous DKK-3 protein, which was consistent with a suppressed Wnt/β-catenin signaling cascade. In addition, as low-density lipoprotein receptor-related protein 6 (LRP6) is a receptor of DKK-1 and DKK-2 and their interaction on the cell surface inhibits Wnt/β-catenin signaling, it was examined whether the exogenous DKK-3 protein affects LRP6-mediated Wnt/β-catenin signaling. The LRP6 gene was silenced and the effects of DKK-3 on the time course of the upregulation of p-β-catenin expression were subsequently analyzed. Notably, LRP6 depletion elevated the base level of p-β-catenin; however, there was no significant effect on its upregulation course or expression pattern. These findings indicate that exogenous DKK-3 upregulates p-β-catenin and inhibits Wnt/β-catenin signaling in an LRP6-independent manner. Therefore, exogenous DKK-3 protein may inhibit the proliferation of KPK1 cells via inactivating Wnt/β-catenin signaling.

Inhibition of glycogen synthase kinase-3 beta induces apoptosis and mitotic catastrophe by disrupting centrosome regulation in cancer cells

Glycogen synthase kinase-3 beta (GSK-3β) has been investigated as a therapeutic target for numerous human diseases including cancer because of their diverse cellular functions. Although GSK-3β inhibitors have been investigated as anticancer reagents, precise biological mechanisms remain to be determined. In this study, we investigated the anticancer effects of GSK-3β inhibitors on cancer cell lines and observed centrosome dysregulation which resulted in abnormal mitosis. Mitotic checkpoints sensed the mitotic abnormalities and induced apoptosis. For cells that were inherently resistant to apoptosis, cell death distinct from apoptosis was induced. After GSK-3β inhibitor treatment, these cells exhibited characteristic features of mitotic catastrophe, including distended and multivesiculated nuclei and inappropriate reductions in cyclin B1 expression. This suggested that mitotic catastrophe was an alternative mechanism in cells resistant to apoptosis. Although the role of GSK-3β in centrosomes has not yet been clarified, phosphorylated GSK-3β was localised in centrosomes. From these data, GSK-3β seems to regulate centrosome function. Thus, we propose that centrosome dysregulation is an important mechanism for the anticancer effects of GSK-3β inhibitors and that mitotic catastrophe serves as a safe-guard system to remove cells with any mitotic abnormalities induced by GSK-3β inhibition.

Polypeptide N-acetylgalactosaminyl transferase 3 independently predicts high-grade tumours and poor prognosis in patients with renal cell carcinomas

BACKGROUND

The polypeptide N-acetylgalactosaminyltransferases (GalNAc-Ts) family of enzymes regulates the initial steps of mucin-type O-glycosylation. N-acetylgalactosaminyltransferases might show novel patterns of GalNAc-T glycosylation on tumour-derived proteins, which could influence cancer biology, but its mechanisms are unclear. We investigated the association of GalNAc-T3 and -T6 expressions with clinicopathological features and prognoses of patients with renal cell carcinomas (RCCs).

METHODS

Expressions of GalNAc-T3/6 and cell-adhesion molecules were analysed immunohistochemically in 254 paraffin-embedded tumour samples of patients with RCC.

RESULTS

Of 138 GalNAc-T3+ cases, 46 revealed significant co-expression with GalNAc-T6. N-acetylgalactosaminyltransferases-3+ expression showed a close relationship to poor clinical performance and large tumour size, or pathologically high Fuhrman's grading, and presence of vascular invasion and necrosis. The GalNAc-T3-positivity potentially suppressed adhesive effects with a significantly low β-catenin expression. Univariate and multivariate analyses showed the GalNAc-T3+ group, but not the GalNAc-T6+ group, to have significantly worse survival rates.

CONCLUSION

N-acetylgalactosaminyltransferases-3 expression independently predicts high-grade tumour and poor prognosis in patients with RCC, and may offer a therapeutic target against RCC.

YB-1 suppression induces STAT3 proteolysis and sensitizes renal cancer to interferon-α

Renal cell carcinoma (RCC) accounts for 80-95 % of kidney tumors, and approximately 30 % of RCC patients have metastatic disease at diagnosis. Conventional chemotherapy is not effective in patients with metastatic RCC (MRCC); therefore, immunotherapy with interferon-α (IFN-α) has been employed to improve survival. However, the response rate of MRCC to IFN-α therapy is low. We previously reported that a signal transducer and activator 3 (STAT3) polymorphism was a useful diagnostic marker to predict the response to IFN-α therapy in patients with MRCC. Therefore, we hypothesized the inhibition of STAT3 in the addition of IFN-α therapy might be useful. Moreover, the blockage of STAT3 itself has been reported to enhance the antitumor effects. However, because IFN-α is thought to elicit its therapeutic effect via enhancement of an antitumor immune response mediated by lymphocytes that can be activated by IFN-α administrations, it is probable that the suppression of STAT3 in vivo relates to autoimmune disorders. In the present study, we found Y-box binding protein-1 (YB-1) was poorly expressed in T lymphocytes, as compared with cancer tissues. YB-1 was reported to have an important effect on the STAT3 pathway. Suppression of STAT3 by YB-1 inhibition did not seem to enhance the potential risk for autoimmune disorders. Moreover, we found sensitivity to IFN-α was increased by YB-1 suppression, and this suppression did not down-regulate IFN-α activation of T lymphocytes.

The combination of IFN-alpha2 and IFN-alpha8 exhibits synergistic antiproliferative activity on renal cell carcinoma (RCC) cell lines through increased binding affinity for IFNAR-2

Although there are at least 13 interferon-alpha (IFN-alpha) subtypes in humans, interactions between the subtypes remain unknown. To understand IFN-alpha interactions, we examined the antiproliferative activities and the receptor binding affinities of different combinations of IFN-alpha2 and IFN-alpha8 using six renal cell carcinoma (RCC) cell lines. Although IFN-alpha8 was the more potent subtype, synergistic and antagonistic antiproliferative effects were also observed in certain combinations of IFN-alpha2 and IFN-alpha8. To analyze the interactions between IFN-alpha2 and IFN-alpha8, the receptor-binding kinetics of different combinations of IFN-alpha2 and IFN- alpha8 to the IFN-alpha receptors, IFNAR-1 or IFNAR-2, were measured using a surface plasmon resonance-based biosensor. Unexpectedly, the receptor binding kinetics to IFNAR-2 but not to IFNAR-1 were mutually related to antiproliferative activity and increase in the binding speed (K(a)) for IFNAR-2. Moreover, we observed the increased fluorescence intensity (FI) of biotin-labeled IFN-alpha8 to IFNAR-2 by receptor binding inhibition assay with unlabeled IFN-alpha2 but not the other combinations. These findings indicate that the binding manner of IFN-alpha8 for IFNAR-2 is different from that of IFN-alpha2, suggesting that binding of IFN-alpha8 rather than binding of IFN-alpha2 to IFNAR-2 leads to activation and subsequent antiproliferative activity despite the same antiviral activity in RCC.

The expression of prostate stem cell antigen in human clear cell renal cell carcinoma: a quantitative reverse transcriptase-polymerase chain reaction analysis

OBJECTIVES

To analyse the gene expression level of prostate stem cell antigen (PSCA) in human clear cell renal cell carcinoma (CC-RCC) and its relationship with conventional clinicopathological manifestations, to evaluate its prognostic value for patient outcome, and to determine the effect of PSCA on the progression of CC-RCC.

PATIENTS AND METHODS

We quantified PSCA mRNA level in human RCC cell lines (ACHN, A704, KPK-1, Caki-1, and Caki-2) and in 154 surgical tissue samples (81 from CC-RCC, 73 from normal kidney) using real-time reverse transcriptase-polymerase chain reaction (RT-PCR). The findings were analysed in relation to clinicopathological factors. Immunohistochemical expression was examined using confocal laser scanning light-microscopy.

RESULTS

PSCA was overexpressed in all RCC cell lines. PSCA mRNA levels were significantly higher in CC-RCC than in normal kidney tissue samples (P < 0.001), in G2-G3 than in G1 tumours (P = 0.028), and in advanced disease (T3-T4) than in organ-confined (T1-T2) tumours (P = 0.016). There was significantly higher PSCA mRNA expression in patients with M1 than in those with M0 disease (P = 0.029). Patients in whom the lesions had high PSCA expression levels had a significantly worse prognosis than those with low PSCA expression levels (P = 0.044). Using immunohistochemical analysis there was markedly greater PSCA expression in CC-RCC than in normal kidney, and in advanced-disease high-grade tumours than in organ-confined low-grade tumours.

CONCLUSIONS

A significant correlation was detected in the gene expression level of PSCA with histological grade, clinicopathological stage and prognosis in CC-RCC. Our data indicate that PSCA is associated with carcinogenesis and progression of CC-RCC.

Decreased expression of REIC/Dkk-3 in human renal clear cell carcinoma

PURPOSE

We examined the expression of REIC/Dkk-3, a possible candidate for a tumor suppressor gene, in human renal clear cell carcinoma (RCCC) cell lines and sporadic RCCC surgical specimens.

MATERIALS AND METHODS

Human RCCC cell lines (Caki-1, Caki-2, ACHN and KPK-1) and several control cell lines were used to examine the expression of REIC/Dkk-3 mRNA and characterize a newly raised antibody specific for REIC/Dkk-3 protein. Pairs of cancerous and adjacent noncancerous tissues were obtained from 20 patients with RCCC. Of them 17 and 7 cases were analyzed by real-time quantitative reverse transcriptase-polymerase chain reaction, and by Western blot analysis and/or immunohistochemical analysis, respectively.

RESULTS

The decreased expression of REIC/Dkk-3 mRNA and protein in human RCCC cell lines, and the specificity of the new antibody were confirmed. In a real-time quantitative reverse transcriptase-polymerase chain reaction study using 17 pairs of RCCC and adjacent normal tissues REIC/Dkk-3 mRNA levels were significantly decreased in carcinoma tissues (by 25% to approximately 95% in 15 pairs). Western blot analysis and immunohistochemistry revealed a significant decrease in REIC/Dkk-3 protein levels in 6 of the 7 and 13 of the 14 RCCC cases analyzed, respectively.

CONCLUSIONS

The decrease in REIC/Dkk-3 mRNA and protein levels was observed irrespective of tumor grade and stage, indicating the involvement of REIC/Dkk-3 in an initial step of malignant conversion. Consequently REIC/Dkk-3 could be a new molecular target for therapeutic measures against RCCC.

Characterization of the antitumor activities of IFN-alpha8 on renal cell carcinoma cells in vitro

Interferon-alpha (IFN-alpha) has a number of therapeutic applications in the treatment of various human cancers and diseases of viral origin. IFN-alpha includes several subtypes, and little has been reported on the biologic properties of the individual subtypes. Here, we report on the individual antitumor effects of five IFN-alpha subtypes, alpha1, alpha2, alpha5, alpha8, and alpha10, against six renal cell carcinoma (RCC) cell lines in vitro. Among the subtypes, IFN-alpha8 most potently inhibited cell proliferation and delayed the G(1)/S transition. Synergistic induction of apoptosis was shown in two of the RCC cell lines when treated with the combination of IFN-alpha and IFN-gamma rather than with either IFN-alpha or IFN-gamma alone. IFN-alpha8 was most effective in the induction of apoptosis when combined with IFN-gamma. In addition, IFN-alpha8 had the strongest ability to upregulate HLA class II antigen expression in the subtypes examined. These data indicate that subtypes of IFN-alpha have disparate antitumor effects in vitro, and in vitro distinctions among the IFN-alpha subtypes should be appreciated more in clinical application.

Human homologues of the Caenorhabditis elegans cell polarity protein PAR6 as an adaptor that links the small GTPases Rac and Cdc42 to atypical protein kinase C

BACKGROUND

Asymmetric cell division in the Caenorhabditis elegans embryos requires products of par (partitioning defective) genes 1-6 and atypical protein kinase C (aPKC), whereas Cdc42 and Rac, members of the Rho family GTPases, play an essential role in cell polarity establishment in yeast and mammalian cells. However, little is known about a link between PAR proteins and the GTPases in cell polarization.

RESULTS

Here we have cloned cDNAs for three human homologues of PAR6, designated PAR6alpha, beta and gamma, comprising 345, 372 and 376 amino acids, respectively. The PAR6 proteins harbour a PDZ domain and a CRIB-like motif, and directly interact with GTP-bound Rac and Cdc42 via this motif and with the aPKC isoforms PKCiota/lambda and PKCzeta via the N-terminal head-to-head association. These interactions are not mutually exclusive, thereby allowing the PAR6 proteins to form a ternary complex with the GTPases and aPKC, both in vitro and in vivo. When PAR6 and aPKC are expressed with a constitutively active form of Rac in HeLa or COS-7 cells, these proteins co-localize to membrane ruffles, which are known to occur at the leading edge of polarized cells during cell movement.

CONCLUSION

Human PAR6 homologues most likely play an important role in the cell polarization of mammalian cells, by functioning as an adaptor protein that links activated Rac and Cdc42 to aPKC signalling.

A novel superoxide-producing NAD(P)H oxidase in kidney

During phagocytosis, gp91(phox), the catalytic subunit of the phagocyte NADPH oxidase, becomes activated to produce superoxide, a precursor of microbicidal oxidants. Currently increasing evidence suggests that nonphagocytic cells contain similar superoxide-producing oxidases, which are proposed to play crucial roles in various events such as cell proliferation and oxygen sensing for erythropoiesis. Here we describe the cloning of human cDNA that encodes a novel NAD(P)H oxidase, designated NOX4. The NOX4 protein of 578 amino acids exhibits 39% identity to gp91(phox) with special conservation in membrane-spanning regions and binding sites for heme, FAD, and NAD(P)H, indicative of its function as a superoxide-producing NAD(P)H oxidase. The membrane fraction of kidney-derived human embryonic kidney (HEK) 293 cells, expressing NOX4, exhibits NADH- and NADPH-dependent superoxide-producing activities, both of which are inhibited by diphenylene iodonium, an agent known to block oxygen sensing, and decreased in cells expressing antisense NOX4 mRNA. The human NOX4 gene, comprising 18 exons, is located on chromosome 11q14.2-q21, and its expression is almost exclusively restricted to adult and fetal kidneys. In human renal cortex, high amounts of the NOX4 protein are present in distal tubular cells, which reside near erythropoietin-producing cells. In addition, overexpression of NOX4 in cultured cells leads to increased superoxide production and decreased rate of growth. The present findings thus suggest that the novel NAD(P)H oxidase NOX4 may serve as an oxygen sensor and/or a regulator of cell growth in kidney.

Chromophilic renal cell carcinoma: cytomorphological and cytogenetic characterisation of four permanent cell lines

Chromophilic renal cell carcinoma is a distinct type of human renal cancer, only recently recognised and defined by its characteristic histomorphological aspect and cytogenetic aberrations. We are the first to report on the establishment and cytogenetic characterisation of a panel of four permanent cell lines, i.e. chromphi-1, -2, -3 and -4, derived from strictly defined renal cell carcinomas (RCCs) of the chromophilic type and kept in continuous culture for up to 5 years. Immunohistochemistry revealed coexpression of vimentin and cytokeratins in all cell lines the cytokeratin polypeptide patterns, however, varying between the different cell lines. By light and transmission electron microscopy, various amounts of cytoplasmatic glycogen deposition were observed, being most pronounced in chromphi-3 and -4. The mean population doubling time ranged from 24 h (chromphi-1) to 51 h (chromphi-4). Chromphi-1 tumour cells produced slowly growing tumours in nude mice using the subrenal capsule assay. In all cell lines, cytogenetic analysis revealed numerical chromosomal aberrations known to be characteristic for chromophilic RCCs, i.e. loss of the Y chromosome, tri- or tetrasomy of chromosomes 7 and 17 as well as various combinations of additional structural and numerical chromosomal aberrations. Karyological aberrations were least pronounced in chromphi-2 and most complex in chromphi-1. Chromosomal aberrations typically affecting the short arm of chromosome 3 in clear cell RCCs were not observed in any of our cell lines.

Expression of cell adhesion molecules in an established and characterized new human renal cell cancer line, CCF-RC7

In order to investigate the importance of cell adhesion molecules (CAMs) in renal cell carcinoma (RCC), a cell line, designated as CCF-RC7, was established from a human RCC of the clear cell type. CCF-RC7 was passaged over 50 times in vitro for 3 1/2 years. The cell line has an epithelial morphology and a doubling time of 30 h, forming colonies in soft agar with an average efficiency of 10.4% and producing clear cell tumors in athymic nude mice. CCF-RC7 cells have an aneuploid-hypotetraploid karyotype with a modal chromosome number of 82 and rearrangements in chromosomes 9, 12 and 14. Immunohistochemical and flow immunocytometric analyses revealed high expression of ICAM-1 (CD54), and Hermes antigen (CD44), which was significantly upregulated by cytokine and PMA treatment. VLA-4 was expressed on approximately 20% of tumor cells and could not be altered by cytokine or PMA stimulation. High expression of sialyl Lewis X was also demonstrated by immunohistological examination. This newly characterized cell line will serve as a useful model for the study of CAMs during hematogenous metastasis and host defense mechanisms in human RCC.

Analysis of nm23 gene expressions in human bladder and renal cancers

We measured nm23-H1 and nm23-H2 mRNA levels in tissues from 22 human bladder cancers and 16 renal cell carcinomas, and in 7 bladder cancer and 6 renal cancer cell lines by Northern blot and slot blot hybridization analyses. Differences in mRNA levels were evaluated in primary tumor tissues and in paired normal tissues and cell lines. Moreover, nm23 gene expression in primary tumor tissues was compared with clinicopathological features. High nm23-H1 and nm23-H2 expression was observed in cancerous areas of human bladder tissue (nm23-H1: p = 0.001, nm23-H2: p = 0.001) and bladder cancer cell lines (nm23-H1: p = 0.001, nm23-H2: p < 0.001) compared with that in normal bladder mucosa. However, mRNA levels of both nm23 genes were not associated with histological grade, pathological stage, tumor metastasis or prognosis. On the other hand, in human renal cell carcinomas, levels of both nm23 mRNAs in tumor tissues were similar to those in paired normal kidneys, but elevated in cultured cell lines (nm23-H1: p = 0.002, nm23-H2: p = 0.014). Moreover, there was a tendency towards high nm23 gene expression in grade 2 tumors compared with grade 1 (grade 1 vs grade 2, nm23-H1: p = 0.107, nm23-H2: p = 0.008; no grade 3 tumors in this study) and in high stage renal cancers (< or = stage II vs stage III < or =, nm23-H1: p = 0.023, nm23-H2: p = 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Cytomorphological, cytogenetic, and molecular biological characterization of four new human renal carcinoma cell lines of the clear cell type

Four new permanent cell lines (RCC-A, -B, -C, and -D) derived from different human renal cell carcinomas of the clear cell type were established in tissue culture. The cell lines displayed characteristic differences in cell size and shape, which allowed individual identification by phase contrast microscopy. Ultrastructurally, the cell lines exhibited varying amounts of cytoplasmatic glycogen and lipid. Immunohistochemistry revealed co-expression of vimentin and cytokeratin in all cell lines. The mean population doubling time ranged from 27 h (RCC-A) to 104 h (RCC-D). RCC-B and -C cells produced slowly growing tumours after heterotransplantation into nude mice, whereas RCC-A and RCC-D cells were non-tumorigenic. The modal chromosome number was either near-diploid (RCC-A, -B, and -C) or near triploid (RCC-D). Clonal abnormalities affecting the short arm of chromosome 3 were seen in all cell lines. Northern blot analysis revealed no expression of the proto-oncogenes c-fos, c-ros, and c-mos, whereas c-Ki-ras expression was observed in all cell lines. Expression of c-myc was observed in RCC-A, RCC-B, and RCC-D cells, whereas c-raf expression could be detected in RCC-B and RCC-D. Tumour suppressor gene p53 mRNA was observed in the cell line RCC-D.

Cooperative roles of hepatocyte growth factor and plasminogen activator in tubular morphogenesis by human microvascular endothelial cells

Epidermal growth factor (EGF) or transforming growth factor-alpha (TGF-alpha) stimulated cell migration, chemotaxis, and the expression of tissue-type plasminogen activator (t-PA) in human omental microvascular endothelial (HOME) cells. Hepatocyte growth factor (HGF) stimulated cell proliferation, but had a negligible stimulatory effect on cell migration, the expression of t-PA and tube-like formation into collagen gel in HOME cells. Basic fibroblast growth factor stimulated cell proliferation, cell migration, tubulogenesis and the expression of urokinase-type plasminogen activator (u-PA) in bovine aortic endothelial (BAE) cells. HOME and BAE cells had both high- and low-affinity receptors for HGF. In BAE cells, u-PA activity and tube-like structures in collagen gel were induced in the presence of HGF alone. In contrast, in HOME cells, t-PA activity and tube-like structures were induced in the presence of TGF-alpha alone, but not in the presence of HGF alone. However, we observed a marked induction of tube formation by HOME cells when both t-PA and HGF were added simultaneously. In the model system for tumor angiogenesis, when HOME cells were co-cultured with a renal cancer cell line, KPK13, tube-like structures were induced in the presence of HGF:KPK13 cells expressed large amounts of t-PA mRNA. Our present study suggested that HGF in concert with active t-PA could be angiogenic in HOME cells.

Orthotopic implantation is essential for the selection, growth and metastasis of human renal cell cancer in nude mice [corrected]

Human neoplasms are heterogeneous for a variety of biological properties that include invasion and metastasis. The presence of a small subpopulation of cells with a highly metastatic phenotype has important clinical implications for diagnosis and therapy of cancer. For this reason, it is important to develop an animal model for the selection and isolation of metastatic variants from human neoplasms and for testing the metastatic potential of human tumor cells. We have implanted human renal cell carcinoma (HRCC) cells (obtained from a surgical specimen) into different organs of nude mice and then recovered the tumors and established each in culture. The 5 established lines differed in their biological-metastatic properties and had a unique karyotype, indicating that growth at different organs selects for different subpopulations of HRCC. Moreover, the HRCC did not metastasize unless they were implanted orthotopically. These findings indicate that the appropriate nude mouse model for studying the biology and therapy of HRCC must be based on the orthotopic implantation of tumor cells.

Chromosome analysis of a newly established renal carcinoma cell line

A renal cell carcinoma has been established as a cell line in vitro. Repeated chromosome analyses of the cell line revealed a stable clone with the modal chromosome number 80 and three pairs of marker chromosomes, M1-M3. M1 and M2 resulted from a translocation between a chromosome #3 deleted in band p14 and a normal #7: M1 = der(3)t(3;7) (:3p14----cen----3q24::7q21----7qter), and M2 = der(7)t(3;7)(3qter----3q24::7q21----cen----7pter ). M3 was a small metacentric chromosome, probably consisting of the centromeric portion of a #3: del(3)(:p14----cen----q12:). No other structural changes were present. Our findings are in agreement with those of previous studies, stating that rearrangements of 3p12-14 are primary cytogenetic events in renal cell carcinomas, even though this can only be inferred in this case. Thus, this cell line may be useful for further molecular and biochemical studies.

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

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 simultaneous expression of the intermediate filaments cytokeratin and vimentin. Flow cytometric analysis of DNA content reveals a major hyperdiploid population.

Establishment and characterization of a new human renal cell carcinoma cell line (KRC/Y)

A new renal cell carcinoma (RCC) cell line (KRC/Y) has been established from a surgical specimen of a 41-yr-old Japanese female patient with RCC composed of both clear cells and granular cells. This cell line has been maintained for more than 15 mo. through 45 passages with a stable growth. KRC/Y cells have clear or eosinophilic polygonal cytoplasm and round to oval nuclei with one or two nucleoli, and proliferate in a pavementlike cell arrangement with a lack of contact inhibition. By electron microscopy, these cells contain abundant fat droplets and glycogen granules or well-developed organelles or both, which were also observed in the original tumor. The doubling time of these cells at the 15th passage was 73 h. The chromosome number was from 37 to 45 with a hypodiploid modal number of 42. Tumorigenicity was identified by tumor formation after subcutaneous injections of KRC/Y cells in nude mice, which showed close resemblance to the original tumor by light and electron microscope observations.

Rationale and methods for the use of nude mice to study the biology and therapy of human cancer metastasis

Human neoplasms are biologically heterogeneous. The extensive cellular diversity found in malignant neoplasms is generated by the rapid emergence of clonal subpopulations of tumor cells with different properties that include invasion, metastasis and responsiveness to treatment. Studies in rodent systems have indicated that cancer metastases can be clonal in their origin and that different metastases can originate from different progenitor cells from the primary tumor. This metastatic heterogeneity of tumor cells has many ramifications for studies of tumor biology, in general, and studies of therapy, in particular. The heterogeneous nature of metastatic human neoplasms can now be studied under defined conditions in healthy athymic nude mice. The neoplasms must be free of mouse pathogens and the mice must be kept in specific-pathogen-free conditions. Careful consideration must be given to the intimate tumor-host relationship for each tumor system studied, because the metastatic potential of human neoplasms can vary with the site of implantation into nude mice. Several methods for studying the biology of human neoplasms in the nude mouse are described as well as techniques to assure the success of these studies. The data show that the healthy young nude mouse can be a useful in vivo model for ascertaining the metastatic potential of human neoplasms, for selecting and maintaining cell variants of high metastatic potential from heterogeneous human tumors, and for studying therapeutic agents directed against metastatic cells proliferating in visceral organs.

Evidence for proximal tubular cell origin of a sarcomatoid variant of human renal cell carcinoma

A pure sarcomatoid variant of renal cell carcinoma obtained from a hydronephrotic kidney of an elderly white female was grown in tissue culture. Two parallel cell lines, one from the primary neoplasm and the other from a seeded metastasis within the same kidney have been cultured for more than 60 passages over a period of three years. Structural and functional studies of this neoplasm confirmed that it originated from proximal tubular cells.

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

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.

Study of the normal human kidney and kidney cancer with monoclonal antibodies

The ability to establish immortal tissue culture lines of human renal cancer as well as short-term lines of autologous normal kidney epithelium offers a unique system to probe the differences between a neoplastic cell and its normal counterpart. Monoclonal antibodies have been prepared against cell surface differentiation antigens of normal and neoplastic human kidney. The detected antigens have been biochemically characterized, and the molecular phenotypes of these cells is being unraveled. Differences in gene expression are becoming apparent between the normal and neoplastic kidney cell. Preliminary results indicate that these differences appear to have clinical significance.