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Cell Biology and Metabolism Branch, National Institute of Child Health and Human Development [R. S. B., R. S.]; Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute [J. R. V., W. M. L.]; and Laboratory of Biosystems and Cancer, Center For Cancer Research, National Cancer Institute [R. D. K.], NIH, Bethesda, Maryland 20892
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ABSTRACT |
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Introduction |
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and HIF-2. These results explain the apparent misregulation of hypoxia-inducible genes under normal oxygen levels in cell lines not expressing pVHL. The HIF targets that are overexpressed in VHL-deficient cell lines include the GLUT-1, vascular endothelial growth factor, and several metabolic enzymes (3)
. Presumably, the overexpression of vascular endothelial growth factor leads to the highly vascular nature of these tumors. Current knowledge about cancer suggests that all of the cancer cells exhibit relaxed control over entrance into and/or progression through the cell cycle (4)
. It is now generally believed that some component of the Rb pathway is altered in a large percentage of human tumors (5)
. The Rb pathway regulates cell cycle progression from G1 to S phase. Loss of either Rb or p16 expression releases cell cycle control via loss of p16 inhibition of the cyclin D/CDK4 complex or loss of Rb inhibition of the E2F transcription factor. Alternatively, the Rb pathway can be disrupted by overexpression of cyclin D1, as is commonly observed in breast cancer. RCC cell lines that arise because of inactivation of the VHL gene have been shown to be resistant to cell cycle arrest when deprived of exogenous growth factors (6)
. Furthermore, this in vitro phenotype is reversed with the reintroduction of WT pVHL. Studies of Rb in RCC have demonstrated that loss of Rb expression is rarely seen in these cancers (7)
. On the other hand, p16 expression is lost in only 
30% of the RCCs, with p16 loss occurring by a variety of mechanisms including gene mutation, deletion, or silencing via hypermethylation (7
, 8)
. We decided to undertake a survey of cell cycle proteins in RCC cell lines to determine the source of their failure to remain quiescent on growth factor withdrawal. Here we demonstrate that the absence of pVHL expression is responsible for enhanced expression of cyclin D1 and that reintroduction of WT pVHL represses cyclin D1 overexpression. In addition, our work reveals that pVHL mediates the hypoxia-inducible, regulated expression of this critical cell cycle regulator. This unexpected regulation is observed only after reintroduction of pVHL into cancer cell lines that emerged as the result of loss of functional pVHL. |
Materials and Methods |
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Retroviral Infection.
Recombinant retroviruses were obtained by transfection of the relevant retroviral construct into Phoenix cells. Medium from these cells was collected 48 h after transfection and was used to infect exponentially growing 111, 121, and T20 RCC cells. Puromycin resistance suggested an 75% infection efficiency.
Cell Cycle Analysis.
Cells were trypsinized, washed with 1x PBS, and treated with RNAase A, followed by incubation in PI. Stained cells were analyzed on a Becton Dickinson FACScan flow cytometer. For BrdUrd analysis, cells were cultured in medium (containing 10% or 0% serum depending on the experimental conditions) containing 10 µM BrdUrd for 1 h. Cells were then trypsinized, washed with 1x PBS, and fixed in methanol for 1 h at -20°C, followed by staining with FITC-conjugated anti-BrdUrd antibodies and PI in accordance with the manufacturer’s specifications. BrdUrd/PI-stained cells were also analyzed on a Becton Dickinson FACScan flow cytometer.
Antibodies.
The following antibodies were used as probes for Western blotting: cyclin D1 (DCS-6; PharMingen and Santa Cruz), p27kip (57; Transduction and Calbiochem), Rb (G3–245), cyclin A (BF683; PharMingen), CDK4 and CDK6 (PharMingen and Calbiochem), GLUT-1 (Alpha Diagnostic), HIF-1 (54; Transduction), cyclin D2 (34B1–3; Oncogene), and cyclin D3 (G107–565; PharMingen). The following antibodies were used specifically for immunoprecipitation: cyclin D1 (Neomarkers) and VHL (Ig32; PharMingen).
Cell Lysis, Western Blotting, and Immunoprecipitation.
For protein analysis, cells were scraped and lysed on ice in IP-B buffer [20 mM Tris-HCl (pH 7.4), 1% NP40, 1 mM sodium orthovanadate, and "complete-mini" protease inhibitor tablet (Boehringer)] for 45 min on ice. After centrifugation and protein concentration determination (D/C Protein Assay; Bio-Rad), 100-µg aliquots of lysates were resolved by SDS-PAGE analysis. Proteins were transferred to Immobilon-P membrane (Millipore), blocked for 1 h in 5% nonfat dry milk (in 1x PBS and 0.1% Tween 20, 1x PBS-T). Blots were probed with the indicated antibodies for either 1 h at room temperature or overnight at 4°C. Protein bands were visualized with horseradish peroxidase-conjugated antimouse or antirabbit IgG and enhanced chemiluminescence detection system (Amersham). For immunoprecipitation, 1–3 mg of protein lysates were precleared with 50 µl of packed Gamma-Bind Sepharose beads (Pharmacia) for 2–3 h at 4°C. Lysates were then mixed with 100-µl packed beads and 10 µg of the indicated antibody, and then rocked overnight at 4°C. Beads were washed three to five times in 1x PBS-T, eluted with SDS sample buffer, and resolved by SDS-PAGE analysis followed by Western blotting.
Metabolic Labeling.
Cells growing in tissue culture dishes were incubated at 37°C for 1 h in DMEM (-methionine, -cysteine) with 10% dialyzed FCS. The cells were pulse-labeled for 30 min in complete DMEM with 0.1 mCi/ml [35S]methionine/cysteine (ICN) and chased for indicated times. Cyclin D1 was immunoprecipitated as described earlier and quantitated by a phosphorimager.
Northern Blotting.
Total RNA was prepared using Trizol (Life Technologies, Inc.), and 2.5–5 µg was denatured with glyoxal and then run on a 1.25% agarose gel in 4-morpholinepropanesulfonic acid buffer. The RNA was transferred to Nytran (S & S), heated to remove the glyoxal modification, and hybridized in Hybrisol I (Intergen). DNA probes, filter hybridization, and washing were carried out using standard protocols.
Hypoxia Assays.
Cells growing in 15-cm dishes were incubated for 12–15 h in hypoxia chambers (Billups-Rothenberg) containing 0.5% oxygen, 5% carbon dioxide, and 95% nitrogen at 37°C. Parallel normoxic plates were run under standard conditions.
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Results |
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. At this time point, the estimated level of S phase cells was <1% for WT cells and 3% for pRc cells. Whereas WT cells maintained their cell cycle arrest for the duration of the time course, the pRc cells re-entered the cell cycle around 115 h (S phase of 11%). By 140 h after release, the pRc cells underwent massive apoptosis (as measured by annexin V FACS analysis; data not shown), whereas the arrested WT cells remained adherent and viable for the remainder of the time course.
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). As both lines synchronously progressed through a single cell cycle, cyclin A expression and hyperphosphorylated ppRb (hyperphosphorylated retinoblastoma protein) increased and then decreased as would be expected. Additionally, p27kip, a CDK inhibitor, was down-regulated during proliferation and up-regulated during cell cycle arrest. As pRc cells re-entered the cell cycle, cyclin A and ppRb expression were induced, whereas p27kip expression was attenuated. However, cyclin D1 remained high throughout the time course in the pRc cells. In contrast, cyclin D1 remained low in WT cells increasing slightly only during the initial proliferation phase at 26 h. In pRc cells, cyclin D1 overexpression was observed at the zero time point (contact inhibition in 10% serum), suggesting that overexpression of cyclin D1 was independent of growth. Cyclin D3 did not show any significant differences during this time course, whereas cyclin D2 was not detectable in either cell line. We examined the effect of reintroducing WT pVHL into three additional VHL-deficient RCC cell lines. Reintroduced pVHL into these cell lines resulted in attenuation of cyclin D1 overexpression (Fig. 1C)
. Given these data, cyclin D1 appeared to be specifically and constitutively overexpressed in VHL mutant RCC cells, and reintroduction of WT pVHL into these cells resulted in a dramatic decrease in the cyclin D1 level.
Cyclin D1 is regulated by many post-transcriptional mechanisms including the ubiquitin-mediated proteolysis pathway (11)
. Recent evidence has demonstrated that pVHL can function as an E3-ubiquitin ligase (12)
, so we investigated whether pVHL regulated cyclin D1 protein half-life. The stability of cyclin D1 protein in VHL mutant and WT cells was assessed by [35S]methionine/cysteine pulse-chase analysis. As shown in Fig. 2A
, the kinetics of cyclin D1 degradation were similar in 786–0 WT and pRc cell lines at log phase and at contact inhibition (t1/2 = 15–30 min). However, the pRc cells synthesized 3-fold more cyclin D1 protein than did the WT cells during log phase increasing to 6-fold more at contact inhibition. This difference in synthetic rate was also seen in the three "VHL-rescued" RCC lines presented earlier (data not shown). Using four independent WT and pRc clones, we examined the expression of cyclin D1 mRNA at contact inhibition by Northern blotting (Fig. 2B)
. All four of the pRc cell lines manifested significantly higher levels of cyclin D1 mRNA in comparison to the four WT cell lines studied (a 5–10-fold difference). There was also a close correlation between cyclin D1 mRNA and protein levels in each of the eight cell lines. These results support the increased expression of cyclin D1 in these cell lines is because of increased mRNA expression and not because of a post-translational mechanism.
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. In addition, cyclin D1 coprecipitated p27kip. The total amount of CDK4 protein but not CDK6 protein was elevated in the pRc cells (Fig. 3B)
, whereas CDK4 mRNA levels were similar in the two cell lines (data not shown), and this difference was most significant in contact-inhibited cells. This suggests a post-transcriptional mechanism to account for the elevated CDK4 protein level in the pRc cells. As shown in Fig. 3C
, Western blot analysis of cycloheximide-treated cells indicated that the CDK4 protein was extrapolated to be significantly more stable in pRc cells (t1/2 = 5.7 h) than in WT cells (t1/2 = 2.2 h).
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and HIF-2, targeting them for degradation under normoxic but not hypoxic conditions (2
, 14
, 15)
. It is pVHL, acting as an F-box protein, which recognizes the HIF transcription factors. With the loss of pVHL, numerous hypoxia-inducible genes are constitutively expressed because the HIFs are stabilized. The elevated expression of the cyclin D1 mRNA in the absence of pVHL led us to examine whether cyclin D1 was also a hypoxia-induced gene.
Contact-inhibited 786–0 WT and pRc cells were incubated in hypoxia for 14 h, and the expression patterns of GLUT-1 and cyclin D1 were examined. As shown in Fig. 4A
, GLUT-1 expression was significantly up-regulated in hypoxia compared with normoxia in the WT cells, whereas it was constitutively elevated in the pRc cells. In pRc cells, cyclin D1 expression was attenuated on exposure to hypoxia although still significantly higher than in normoxic WT cells. Interestingly, the expression of cyclin D1 in WT cells was induced 3-fold by hypoxia. Northern blot analysis indicated that the induction of cyclin D1 in WT cells was the result of higher cyclin D1 mRNA. Western blots were repeated several times with two different pairs of WT and pRc clones to obtain a hypoxia:normoxia ratio of cyclin D1 and GLUT-1 protein expression. In hypoxia, cyclin D1 protein was induced by 5.5-fold in the WT cells, whereas it was slightly reduced by 0.7-fold in pRc. GLUT-1 protein was induced in hypoxia by 12.1-fold in WT, whereas it remained relatively constant in pRc (1.2-fold).
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. The ratio of cyclin D1 protein induction by hypoxia was greatest in serum-starved cells (10-fold) in the WT cells. This effect was not unique to 786–0 cells but was also observed in the independent VHL-negative lines 121 and T20. We next examined whether the pVHL-dependent hypoxia induction of cyclin D1 was observed in VHL-positive cell lines of kidney origin as well as other cell types. The expression of HIF-1 was used to confirm the establishment of hypoxia. As shown in Fig. 4C
, when the four VHL-positive kidney cell lines were exposed to hypoxia, the HIF-1 was induced, whereas cyclin D1 protein levels were either unchanged or attenuated. Introduction of additional pVHL expression into the 171 cells (171 + pVHL) did not affect the cyclin D1 expression under hypoxia, suggesting that exogenously expressed and/or overexpression of pVHL does not explain our findings. Furthermore, analysis of other cell types also revealed that cyclin D1 protein is either unaffected or down-regulated by hypoxia. This data suggests that cyclin D1 is not induced by hypoxia in cell lines derived from a VHL-positive lineage.
One question is whether in VHL-negative RCC cells the dysregulation of cyclin D1 expression is the locus of the Rb pathway inactivation. Rb protein was detected by Western blot analysis in all of the RCC cell lines used in this study (data not shown). However, p16 loss could also inactivate the Rb pathway, and this has been found in 30% of RCC tumors (8)
. Therefore, we examined the RCC cell lines to determine their p16 status by genomic PCR, RT-PCR, and Western blot analysis using HEK293 and MCF7 cell lines as controls that express normal levels of pVHL (data not shown). The HEK293 cell line was found to retain the p16 gene, exhibited a strong RT-PCR signal, and had detectable protein by Western blot analysis. The breast cancer cell line MCF7 is known to overexpressed cyclin D1 protein because of gene amplification. Genomic PCR from MCF7 DNA did not detect the p16 gene (16)
. Four of the seven RCC cell lines were positive for the p16 gene by genomic PCR. However, only the VHL-positive 112 cell line (with papillary histology) gave a strong RT-PCR product, whereas two of the other three (the VHL-positive 171 and VHL-hypermethylated 121 cell lines) gave weak p16 RT-PCR products. The 121 cell line did not have detectable p16 protein by Western blot analysis. In summary, there was no consistent pattern to the presence or absence of the p16 gene or the p16 protein in relation to the VHL status of the cell lines.
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Discussion |
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TopABSTRACTIntroductionMaterials and MethodsResultsDiscussionREFERENCES |
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Cyclin D family of proteins (D1, D2, and D3) are important in the G1 to S phase transition (4) . Cyclin D1 was the only member of the cyclin D family that showed differential expression in its level in a VHL-dependent manner. The cyclin D proteins are primarily involved in cell cycle progression through their binding to the CDKs CDK4 and CDK6. The cyclin D/CDK complex phosphorylates Rb, which then disassociates from the E2F transcription factor family of proteins. The E2F transcription factors are then able to reprogram the cell to enter the S phase. The CDK inhibitor p16 binds to the cyclin D/CDK complex and inhibits it from phosphorylating Rb causing the cell to arrest in G1. A similar model applies for arresting cells in G0, although this may be signaled through cell density (contact inhibition) as well as through growth factor levels via the RAS or MYC pathways (17) .
Current literature strongly suggests that exposure to hypoxia generally inhibits cell proliferation, as well as global transcription and translation in multiple cell types (18)
. Specifically, it has been hypothesized that the cellular response to hypoxia involves reversible cell cycle arrest characterized by dephosphorylated Rb, loss of CDK activity, and decreased cyclin synthesis. However, relevant to our findings, hypoxia can actually induce certain cells in the kidney to proliferate (19
, 20)
. Hypoxia induces the expression of erythropoietin in the kidney, which may act as a mitogenic growth factor for kidney cells (21)
. Alternatively, TGF- is overexpressed in VHL-negative kidney cell lines in normoxia but is induced by hypoxia in a VHL-independent manner (22)
. TGF- is also known to stimulate proximal renal tubule cells, which have been proposed but not proven to be the cell of origin of RCC (23)
. Perhaps in this manner, TGF- is playing a significant role in stimulating cell proliferation of certain cell lineages in a VHL-dependent manner in the kidney.
The results reported here suggest that pVHL can mediate the hypoxia-regulated induction of cyclin D1 mRNA levels. This was only observed in VHL-negative tumor cell lines into which WT pVHL had been reintroduced. The overexpression of cyclin D1 that results from pVHL loss may be one mechanism by which the Rb pathway is deregulated in these tumors. No other cell line tested displayed hypoxia induction of cyclin D1. Perhaps these other cell lines have lost the normal hypoxia induction of cyclin D1 via other genetic changes. An intriguing alternative is that only certain cell lineages are capable of pVHL-mediated hypoxia induction of cyclin D1. It would be only in these lineages that the loss of pVHL would induce cyclin D1, and thus only these lineages would give rise to cancer on VHL loss. While speculative, this idea provides a potential explanation for why the loss of VHL, a ubiquitously expressed tumor suppressor gene, gives rise to such a limited range of human cancers.
The link between VHL and the hypoxia-induced expression of cyclin D1 remains mysterious. First of all, we would like to know whether the apparent transcriptional effect is mediated by HIFs. The fact that VHL regulates HIFs and that cyclin D1 in these cells shows VHL-dependent hypoxia induction makes the argument connecting HIF with this effect more compelling. However, such a connection may be direct or indirect. The direct pathway would require the demonstration of functional HREs in the cyclin D1 promoter. Recent work using this approach showed that the immediate upstream promoter sequence (out to position -245) is needed for basal expression of cyclin D1 mRNA, especially, an important CRE element located between -52 and -45 (24) . Careful examination of the cyclin D1 promoter region identified two consensus HREs with the canonical sequence 5' RCGTC 3' (25) . These were located at positions –-552 to -548 and -390 to -386 in a region not found to be important for basal expression of cyclin D1 mRNA. It will be interesting to determine whether these are in fact functional HREs and are responsible for the hypoxia regulation of cyclin D1 observed in these studies.
A more indirect pathway might involve the HIF induction of another pathway, such as TGF-
, which, in turn, regulates cyclin D1 transcription. Regardless of the precise mechanistic pathway, it is intriguing that hypoxia-induced expression of cyclin D1 appears to be restricted (to the extent thus far examined) to these VHL-negative RCC cells. Whether this reflects a property possessed by the lineage of cells that gives rise to these tumors or whether this is a property acquired during the development of VHL-negative RCC, remains unanswered by these observations. Whatever the explanation, these results demonstrate the profound contextspecific regulation of even the most generalized biochemical pathways associated with cancer.
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FOOTNOTES |
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1 To whom requests for reprints should be addressed, at Phone: (301) 496-6353; E-mail: klausner{at}pop.nci.nih.gov 
2 The abbreviations used are: VHL, von Hippel-Lindau; RCC, renal cell carcinoma; pVHL, VHL protein; HIF, hypoxia-inducible factor; GLUT-1, glucose transporter-1; Rb, retinoblastoma; CDK, cyclin-dependent kinase; FACS, fluorescence-activated cell sorter; PI, propidium iodide; BrdUrd, bromodeoxyuridine; WT, wild-type; RT-PCR, reverse transcription-PCR; TGF, transforming growth factor; HRE, hypoxia-inducible factor regulatory element.
Received 12/12/01. Accepted 4/11/02.
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REFERENCES |
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by the von Hippel-Lindau tumor suppressor protein. EMBO J., 19: 4298-4309, 2000.[Medline]
in von Hippel-Lindau (VHL) -/- clear cell renal carcinoma cell proliferation: a possible mechanism coupling VHL tumor suppressor inactivation and tumorigenesis. Proc. Nat. Acad. Sci. USA, 98: 1387-1392, 2001., and other growth factors on renal proximal tubule cells. Lab. Investig., 64: 538-545, 1991.[Medline]
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