You have full text access to this OnlineOpen article

Apoptosis and its relevance to urologists

  1. K.P. Jefferson1,
  2. R.A. Persad1,
  3. J.M.P. Holly2

Article first published online: 24 DEC 2001

DOI: 10.1046/j.1464-410x.2000.00857.x

Issue

BJU International

BJU International

Volume 86, Issue 5, pages 598–606, September 2000

Additional Information

How to Cite

Jefferson, K.P., Persad, R.A. and Holly, J.M.P. (2000), Apoptosis and its relevance to urologists. BJU International, 86: 598–606. doi: 10.1046/j.1464-410x.2000.00857.x

Author Information

  1. 1

    Bristol Royal Infirmary, and

  2. 2

    Department of Clinical Science, Division of Surgery, University of Bristol, Bristol, UK

Publication History

  1. Issue published online: 24 DEC 2001
  2. Article first published online: 24 DEC 2001

SEARCH

SEARCH BY CITATION

ARTICLE TOOLS

Get PDF (96K)

Introduction

  1. Top of page
  2. Introduction
  3. Apoptosis in urogenital organogenesis
  4. Apoptosis in benign urological disease
  5. Apoptosis in urological malignancy
  6. Morphological features of apoptosis
  7. Modulators of apoptosis (ced-9 and egl-1 homologues)
  8. Detecting apoptosis
  9. Conclusion
  10. References
  11. Authors
  12. Appendix 1
  13. Appendix 2

Apoptosis, the phenomenon of genetically programmed eukaryotic cell death, was first described in morphological detail by Kerr et al. in 1972 [1]. Weissmann had postulated the existence of such pathways some 93 years earlier [2]. Apoptosis is essential for normal human development (a conspicuous example is the deletion of mesenchymal tissue to form the fingers and toes), tissue homeostasis, clearance of virally infected cells and immunological tolerance. Inactivating defects in apoptotic pathways have been implicated in many diseases, including developmental abnormalities, autoimmunity and cancers; excessive apoptotic activity may contribute to degenerative neurological and muscular diseases. The cellular control of apoptosis is tightly regulated by a complex network of promoter and inhibitor molecules; as in the cell cycle, there appear to be distinct checkpoints where the balance of these molecules is crucial.

Apoptosis in urogenital organogenesis

  1. Top of page
  2. Introduction
  3. Apoptosis in urogenital organogenesis
  4. Apoptosis in benign urological disease
  5. Apoptosis in urological malignancy
  6. Morphological features of apoptosis
  7. Modulators of apoptosis (ced-9 and egl-1 homologues)
  8. Detecting apoptosis
  9. Conclusion
  10. References
  11. Authors
  12. Appendix 1
  13. Appendix 2

Apoptosis plays a central role in the development of the urogenital tract. ‘Knockout’ mice with deletions of Bcl-2 (encoding an apoptotic regulator) die young with renal failure and have polycystic lesions of the kidneys [3]. Bcl-2 appears to be essential for interactions between the ureteric bud epithelium and the metanephric blastema, resulting in the formation of the renal tubules and collecting system, as are functional caspases. Apoptosis is increased in human polycystic kidney disease and its experimental homologue the cpk/cpk mouse [4–6]. Furthermore, the recently discovered role of angiotensin type 2 (AT2) receptors in normal urinary tract development involves the regulation of apoptosis [7]. The formation of the male urogenital tract depends on apoptosis of cells comprising the Müllerian duct and cloacal membrane, in response to the production of Müllerian inhibiting substance, and on the death of cells within the solid epithelial precursor of the anterior urethra [8].

Apoptosis in benign urological disease

  1. Top of page
  2. Introduction
  3. Apoptosis in urogenital organogenesis
  4. Apoptosis in benign urological disease
  5. Apoptosis in urological malignancy
  6. Morphological features of apoptosis
  7. Modulators of apoptosis (ced-9 and egl-1 homologues)
  8. Detecting apoptosis
  9. Conclusion
  10. References
  11. Authors
  12. Appendix 1
  13. Appendix 2

Renal disease

In adults, chronic mild renal ischaemia results in diffuse renal cell apoptosis with loss of renal function and parenchymal mass. Obstructive nephropathy suppresses the expression of EGF by renal tubular cells, with consequent apoptosis [7].

Benign prostatic hypertrophy

Normal prostate epithelial cells and epithelial cells cultured from foci of BPH are dependent on trophic growth factors for survival. In vivo these factors are synthesized by prostatic stromal cells in response to androgens. In the absence of androgens or growth factor supplementation, benign prostatic epithelial cells undergo apoptosis [9]. In patients treated with 5α reductase inhibitors the distribution of paracrine growth factors changes and apoptosis is increased [10]. The apoptotic index (the number of apoptotic cells/total cell number) of hyperplastic prostate tissue is lower than normal prostate and Bcl-2 expression is higher [11]. In Brown Norway rats, apoptosis declines after castration with advancing age [12]. Such changes may correlate with the development of BPH and prostate cancer in elderly men; indeed, benign enlargement of the prostate appears to result from reduced apoptosis rather than increased cell proliferation [13]. Treatment with the phytotherapeutic saw palmetto extract, α-adrenoceptor blockers and thermotherapy induces apoptosis [14–16].

Male infertility

The role of apoptosis in spermatogenesis is still debated. Adult ‘knockout’ mice deficient in Apaf-1, Bcl-Xl and Bax are infertile, suggesting that apoptosis is essential for the normal development of spermatozoa [17,18]. This is supported by studies on testicular tissue from infertile men with varicoceles, which show lower germ cell apoptosis than in normal tissue. However, other studies have shown increased apoptosis in testicular biopsy tissue from men with azoospermia or severe oligospermia, and in experimental models of cryptorchidism [19–21].

Other benign disease

There is evidence that apoptosis may contribute to erectile dysfunction. Apoptosis is increased in the erectile tissue of diabetic rats, and in rat models of penile denervation and castration [22–24]. Similar apoptotic processes may be responsible for weakness of the rhabdosphincter; in elderly people with incontinence, there is evidence of increased apoptosis in the striated muscle fibres of this sphincter [25].

Apoptosis in urological malignancy

  1. Top of page
  2. Introduction
  3. Apoptosis in urogenital organogenesis
  4. Apoptosis in benign urological disease
  5. Apoptosis in urological malignancy
  6. Morphological features of apoptosis
  7. Modulators of apoptosis (ced-9 and egl-1 homologues)
  8. Detecting apoptosis
  9. Conclusion
  10. References
  11. Authors
  12. Appendix 1
  13. Appendix 2

Apoptotic resistance is a conspicuous feature of carcinogenesis and underlies the resistance of tumours to nonsurgical treatments; elements of apoptotic pathways have the potential to provide useful prognostic indicators and therapeutic targets. Indeed, many of the previously characterized oncogenes and tumour suppressor genes encode proteins which have an apoptotic function (notably Bcl-2 and p53). At present, the therapeutic induction of apoptosis depends on nonspecific cytotoxic agents such as cytotoxic drugs and radiotherapy. Pro-apoptotic peptides have recently been synthesized and accurately targeted to malignant cells; this may be the prelude to the safe clinical induction of apoptosis [26].

Prostate cancer

Unlike their benign precursors, cultured prostatic cancer cells can resist apoptosis after growth factor deprivation. Their apoptotic pathways have been studied in several cultured cell lines and animal models. Fas-mediated apoptosis can be induced in all cell lines so far studied [27]. Withdrawal of androgen stimulation from androgen-dependent cells increases the susceptibility to apoptosis; overexpression of Bcl-2 prevents this, an effect which in turn can be blocked by the use of antisense oligonucleotides to Bcl-2 mRNA. Pro-apoptotic ceramide molecules were able to restore radiosensitivity to radioresistant prostate cells [28].

Many molecules have the potential to induce apoptosis in prostate cells, including vitamin D [29] and some dietary constituents [30,31]; these may contribute to the huge geographical variation in prostate cancer incidence. Other inducers of prostatic apoptosis are under consideration as potential treatments for prostate cancer [32,33].

Many clinical studies have examined the expression of apoptotic molecules, most commonly Bcl-2 and p53. Primary prostate cancers were shown to express higher levels of Bcl-2 than normal epithelium and the level of Bcl-2 expression correlates with androgen resistance [34]. P53 expression correlates with the development of metastatic potential. The response of localized prostate cancer to radiotherapy correlated with the expression of Bcl-2 and p53, shown by immunostaining of needle biopsy tissue; such markers might therefore be useful for prognostication and therapy selection [35].

Bladder cancer

Experimental models of bladder cancer have shown that overexpression of Bcl-2 and mutant p53 gives some resistance to drug-induced apoptosis [36–38]. The p53 status of primary bladder cell lines relates to the grade of the tumour and predicts apoptotic responses to chemotherapeutic agents [39].

Studies of resected bladder specimens support these findings. The apoptotic index correlates with stage, grade, response to radiotherapy and disease-free survival in invasive bladder cancer [40,41]. Expression of wild-type, as opposed to mutant p53, is associated with sensitivity to chemotherapeutic agents, but equivocal results have been reported for the response to topical BCG immunotherapy [42,43]. Bcl-2 has been extensively studied in relation to stage and grade; initial results from the immunostaining of paraffin sections were equivocal [44,45]; however, more recent studies using the RT-PCR to assay mRNA suggest that increased Bcl-2 expression correlates with increasing stage and grade [46]. Bcl-2 expression analysis may also have a role in selecting patients for neoadjuvant chemotherapy before curative radiotherapy [47]. With increased understanding of the biological role of Bcl-2 family proteins, the Bcl-2/Bax ratio has come under scrutiny; an elevated ratio has been associated with higher stage and grade, and an increased rate of tumour recurrence [48,49]. An increased rate of recurrence is also associated with tumours expressing high levels of the apoptotic inhibitor survivin [50].

Testicular cancer

Unlike bladder and prostate tumours, the expression of neither p53 nor Bcl-2 family members has yet been shown to correlate with testicular tumour cell line sensitivity to cisplatin-induced apoptosis [51].

Renal cell carcinoma

The apoptotic index of renal cell cancers is an independent prognostic indicator [52], but there has been no consistent correlation between immunohistochemical staining for Bcl-2 and stage, grade or prognosis in RCC [53–55]. Soluble Fas protein (sFas) levels were higher in RCC than normal controls and these levels tended to fall after nephrectomy [56]. SFas may interfere with FasL:Fas binding and inhibit apoptosis in renal cells, a hypothesis supported by the work of Gerharz et al.[57] who showed impairment of the Fas-activated apoptotic pathway in renal cancer cell lines. It is possible that such mechanisms prevent apoptosis and contribute to the extreme radio- and chemo-resistance characteristic of RCCs.

Paediatric renal tumours

The protein product of wild-type WT1 (Wilm's tumour) gene can regulate the transcription of Bcl-2, but there are conflicting reports as to whether it upregulates or represses transcription [58,59]. This may relate to differences in the cell culture models used. In clinical specimens, a high apoptotic index correlates with better prognosis, but no correlation has been detected between Bcl-2 expression and prognosis [60,61]. However, the expression of TRAIL, a death receptor ligand, was lower in clear cell sarcoma of the kidney and rhabdoid tumours of the kidney than in normal kidneys [62].

Morphological features of apoptosis

  1. Top of page
  2. Introduction
  3. Apoptosis in urogenital organogenesis
  4. Apoptosis in benign urological disease
  5. Apoptosis in urological malignancy
  6. Morphological features of apoptosis
  7. Modulators of apoptosis (ced-9 and egl-1 homologues)
  8. Detecting apoptosis
  9. Conclusion
  10. References
  11. Authors
  12. Appendix 1
  13. Appendix 2

The principle morphological features of apoptosis are:

  • • cell shrinkage with membrane ‘blebbing’

    • loss of cell adhesion

    • nuclear pyknosis

    • organelle degradation

    • repackaging of the cell into membrane-surrounded vesicles for phagocytosis by neighbouring cells.

These features are energy- (ATP) dependent, occur in an orderly fashion and do not trigger an inflammatory response; the irreversible activation of apoptosis can occur within seconds of an apoptotic trigger, and cell death within hours. Apoptosis is thus a nondisruptive way of eliminating cells in an orderly manner, in contrast to necrosis, which involves cellular swelling, nuclear dissolution and disruption of the plasma membrane, with induction of an inflammatory response.

Apoptosis in Caenorhabditis elegans

Apoptosis shows strong phylogenetic conservation and dissection of the apoptotic process in the nematode C. elegans has been informative [63]. C. elegans normally has a tightly controlled number of cells; mutations in genes regulating apoptosis reduce or increase this number, and can be relatively easily identified. Such genetic mutants revealed a hierarchy of genes involved in apoptosis; these were termed ced (‘cell death abnormal’). Two, ced-3 and ced-4, were essential for programmed cell death, while ced-9 inhibited it. Recently a fourth gene, egl-1, has been found to oppose apoptosis and promote differentiation ( Fig. 1). Subsequent research has revealed many mammalian homologues of the ced genes, as detailed in Table 1 and Fig. 2.

Figure 1. The basic model for apoptosis in C. elegans.

Download figure to PowerPoint

image
Table 1.  Mammalian homologues of the ced gene
C. elegans gene FunctionMammalian homologues
ced-3Cysteine protease zymogenprocaspases
ced-4Activating cofactor for ced-3Apaf-1, FADD
ced-9Inactivating cofactor for ced-3/4Bcl-2, Bcl-XL
egl-1Inhibitor of ced-9 (BH3 domain only) BID, BIK, BAD

Figure 2. The basic model of mammalian apoptotic pathways.

Download figure to PowerPoint

image

Caspases (mammalian ced-3 homologues)

These highly specific cysteine aspartases recognize individual tetrapeptide motifs upstream of cysteine/aspartate cleavage sites and irreversibly break polypeptide chains. They are synthesized and stored as zymogens (procaspases) with low, but detectable, proteolytic activity. Cascade activation of procaspases occurs in a fashion analogous to complement activation and blood clotting. As with these systems, a complex network of activating and inhibiting cofactors exists (described below) [64].

The sequestration of procaspases and their substrates in separate cellular compartments may also have an important regulatory role [65,66]. ‘Upstream’ caspases localize to the plasma membrane and can be activated by death receptor complexes. Activation releases them from the plasma membrane into the cytoplasm, allowing activation of downstream caspases (e.g. caspase 3)

The creation of genetic ‘knockout’ mice for caspases shows their importance for normal fetal development. Caspase 8 knockouts die in utero with cardiac malformations; caspase 3 and 9 knockouts die perinatally and have a massive excess of CNS neurones.

Caspase substrates

The specificity of the caspase enzymes has assisted the identification of their substrates. These include regulators of DNAse enzymes (the enzymes responsible for the characteristic DNA ladder seen in apoptosis), structural proteins and molecules involved in cell replication.

Modulators of apoptosis (ced-9 and egl-1 homologues)

  1. Top of page
  2. Introduction
  3. Apoptosis in urogenital organogenesis
  4. Apoptosis in benign urological disease
  5. Apoptosis in urological malignancy
  6. Morphological features of apoptosis
  7. Modulators of apoptosis (ced-9 and egl-1 homologues)
  8. Detecting apoptosis
  9. Conclusion
  10. References
  11. Authors
  12. Appendix 1
  13. Appendix 2

The Bcl-2 family

Bcl-2 was discovered in B cell lymphoma cells where the accumulation of the Bcl-2 protein dramatically increased cell lifespan. It associates with organelle membranes (notably mitochondria) and is able to form channels in artificial membranes [67,68]. Bcl-2 is a potent inhibitor of apoptosis. Eighteen proteins with Bcl-2 homology have been identified. Four conserved domains (BH1–4) are present, which allow oligomerization. Members of the Bcl-2 family can be classified according to their domain content and function ( Table 2). The ratio of pro- to anti-apoptotic Bcl-2 family members at the mitochondrial membrane appears to be a key determinant of cell survival or death by apoptosis.

Table 2.  Members of the Bcl-2 family
MemberGeneFunction
BH1–4 containingBcl-2 and Bcl-XlAnti-apoptotic
BH1–3 containingBax and BakPro-apoptotic
BH3 onlyBid, BadPro-apoptotic

This ratio can be affected by altering rates of protein synthesis, but subtler, post-translational modifications can alter the activity of Bcl-2 family members. These allow integration of multiple pro- and anti-apoptotic signals from cell-signalling pathways. Bcl-2 expression within mitochondria and other organelles may provide a means by which organelle dysfunction can be detected and the cell harmlessly eliminated. For example, pro-apoptotic Bid is activated when cleaved to form tBid. This localizes to the mitochondria causing cytochrome c release and caspase activation [69,70]. Bad is regulated by phosphorylation; phosphorylated Bad is retained in the cytosol, and de-phosphorylation allows migration to mitochondria. Mitochondrial kinases may influence events by re-phosphorylating Bad in response to a survival signal [71]. The precise actions of Bcl-2 family proteins within the mitochondria remain elusive. They alter mitochondrial membrane permeability and induce a chain of mitochondrial events as described below.

Other modulators of apoptosis include FLIPs (‘flice inhibitory proteins’) and IAPs (inhibitors of apoptosis) which are mammalian homologues of viral proteins. These molecules impair death-receptor mediated apoptosis which their viral progenitors used to evade T cell-mediated killing of infected cells [71,72]. A prominent IAP, survivin, is expressed at the G2/M regulatory point in the cell cycle. If the centrosome is structurally sound, survivin prevents the cell defaulting to apoptosis and allows progression to mitosis [73].

Apoptotic triggers

There are many apoptotic triggers ( Fig. 3); these may be the presence or absence of a factor or combination of factors. It appears that cells are rescued from apoptotic death by trophic factors; in their absence, or in the presence of conflicting messages, cells default to apoptosis. For example, epithelial cells undergo apoptosis after isolation from the extracellular matrix, perhaps because of loss of integrin receptor stimulation. This is desirable in eukaryotes, where the escape of a single clone may prove fatal to the parent organism.

Figure 3. Integration of apoptotic signals from different triggers.

Download figure to PowerPoint

image

Caspase activation may result from stimulation of specific death receptors or nonspecific triggers which disrupt organelle function. The ratio of active Bcl-2 family proteins determines whether apoptotic signals from the organelles are propagated or terminated ( Fig. 3).

Death receptors

All cells express receptors that, on binding an appropriate ligand, initiate events that may result in apoptosis. These receptors are part of the TNF receptor (TNFR) family. Five death receptors have so far been characterized; Fas, TNFR1, TRAMP, TRAILR-1 and TRAILR-2 [74].

Fas is almost ubiquitous; its ligand FasL is expressed only on T lymphocytes, natural killer (NK) cells and stromal cells within immunologically privileged sites such as the eye and thymus. Known functions include cytotoxic T lymphocyte and NK cell-mediated cell killing; deletion of activated mature T lymphocytes; and removal of inflammatory cells from immunologically privileged sites. Ligand binding causes clustering of the receptors and consequent procaspase activation [75]. Fas mutations cause fatal autoimmune responses in mice, while stimulatory anti-Fas antibodies cause massive hepatocyte apoptosis.

TNFR1 is also ubiquitous but TNF production is restricted. Ligand binding results in trimerization of TNFR1; this may trigger either pro- or anti-apoptotic pathways. TNFα treatment results in a syndrome resembling septic shock, precluding its therapeutic use. TRAMP shows very strong homology to TNFR1. Its ligand (TWEAK) is mostly confined to cells within the spleen, thymus and blood and is induced by T cell activation. TRAILR-1 and -2 are activated by the TNF-related apoptosis-inducing ligand (TRAIL). They may help to maintain peripheral immunological tolerance. TRAIL has therapeutic potential as it does not have the major side-effects of TNFα[76].

Mitochondria

Mitochondria can initiate apoptosis after disruption of electron transport, oxidative phosphorylation or the cellular redox potential [77]. Such situations occur after treatment of cells with apoptosis-inducing agents, e.g. cytotoxic drugs, ceramides (sphingosine phospholipids) and electromagnetic radiation. Mitochondria also amplify apoptotic signals from death receptors. In response to apoptotic stimuli, pro-apoptotic members of the Bcl-2 family gather at the outer mitochondrial membrane, releasing cytochrome c [78], apoptosis inducing factor (AIF) [79] and procaspases, from the intermembrane space, causing caspase 9 activation.

The modulatory effects of p53 and other cell cycle regulators

The p53 tumour suppressor gene encodes a nuclear transcription factor. This regulates the expression of other genes (e.g. p21cipl/waf1) which inhibit cyclin-dependent kinases, blocking progress through the G1 and G2 phases of the cell cycle. Wild-type p53 levels are regulated by its interaction with mdm-2, which leads to p53 degradation.

p53 can induce apoptosis; p53 knockout mice develop normally but their cells are resistant to apoptosis after irradiation or treatment with cytotoxic agents. p53 controls the response to DNA damage, triggering either growth arrest or apoptosis to prevent propagation of mutated DNA [80]. DNA damage leads to p53 phosphorylation, which prolongs its half-life in the nucleus. The mechanism of p53-induced apoptosis remains elusive but it regulates the transcription of apoptotic proteins including Bcl-2, Bax, Fas and TRAIL-2.

Interestingly, cells are hypersensitive to apoptotic stimuli around the time of malignant transformation; this may correlate with increased levels of p53. Subsequently, these cells become more resistant to apoptosis as further genetic mutations accumulate. This raises the possibility that radical nonsurgical treatment of early tumours could induce complete tumour cell apoptosis and cure.

Detecting apoptosis

  1. Top of page
  2. Introduction
  3. Apoptosis in urogenital organogenesis
  4. Apoptosis in benign urological disease
  5. Apoptosis in urological malignancy
  6. Morphological features of apoptosis
  7. Modulators of apoptosis (ced-9 and egl-1 homologues)
  8. Detecting apoptosis
  9. Conclusion
  10. References
  11. Authors
  12. Appendix 1
  13. Appendix 2

Detecting apoptosis is difficult, especially in tissue sections or in vivo; this is a testament to the lack of tissue disruption resulting from apoptosis of individual cells and the lack of synchronization of apoptosis within tissues. From initiation, apoptosis, phagocytosis and degradation of apoptotic debris can be so rapid that no trace is evident after 2 h. Detection in cell culture is easier and usually involves a combination of techniques [81,82].

Morphological assessment is still the ‘gold standard’ method of detection; time-lapse photomicroscopy can show progress through the morphological stages of apoptosis. Flow cytometry can also detect apoptotic cells which have a subnormal DNA content (the ‘sub-G1’ population of cells). Techniques based on detecting DNA strand breaks include the TUNEL assay; blotting techniques can also be used to detect the characteristic DNA ladder. Plasma membrane changes can be detected by the binding of annexin V to phosphatidyl serine residues, which are normally sequestered inside the cell. Caspases, breakdown products and substrates can also be assayed.

Conclusion

  1. Top of page
  2. Introduction
  3. Apoptosis in urogenital organogenesis
  4. Apoptosis in benign urological disease
  5. Apoptosis in urological malignancy
  6. Morphological features of apoptosis
  7. Modulators of apoptosis (ced-9 and egl-1 homologues)
  8. Detecting apoptosis
  9. Conclusion
  10. References
  11. Authors
  12. Appendix 1
  13. Appendix 2

The delineation of the mechanisms controlling apoptosis is the ‘holy grail’ of cellular and molecular biology. Defects of the apoptotic pathway result in considerable morbidity and mortality from both benign and malignant diseases, including many urological disorders. A basic understanding of this process is important for the clinician to comprehend the changes in urological management that are likely to result from improvements in our knowledge.

References

  1. Top of page
  2. Introduction
  3. Apoptosis in urogenital organogenesis
  4. Apoptosis in benign urological disease
  5. Apoptosis in urological malignancy
  6. Morphological features of apoptosis
  7. Modulators of apoptosis (ced-9 and egl-1 homologues)
  8. Detecting apoptosis
  9. Conclusion
  10. References
  11. Authors
  12. Appendix 1
  13. Appendix 2
  • 1
    Kerr JFR, Wyllie AH, Currie AR. Apoptosis: a basic biology phenomenon with wide-ranging implications in tissue kinetics. Br J Cancer 1972; 26: 239
  • 2
    Weissmann A., Paulton EB, Schonland S, Shipley AE, eds. Oxford: Oxford Press, 1889:
  • 3
    Sorenson CM. Life, death and the kidneys: regulation of renal programmed cell death. Curr Opin Nephrol Hypertens 1998; 7: 5 12
  • 4
    Winyard PJ, Nauta J, Lirenman D et al. Deregulation of cell survival in cystic and dysplastic renal development. Kidney Int 1996; 49: 135 46
  • 5
    Kovacs J & Gomba S. Analysis of the role of apoptosis and cell proliferation in renal cystic disorders. Kidney Blood Press Res 1998; 21: 325 8
  • 6
    Araki T, Saruta T, Okano H, Miura M. Caspase activity is required for nephrogenesis in the developing mouse metanephros. Exp Cell Res 1999; 248: 423 9DOI: 10.1006/excr.1999.4424
  • 7
    Pope J, Brock J, Adams M, Stephens F, Ichikawa I. How they begin and how they end: classic and new theories for the development and deterioration of congenital anomalies of the kidney and urinary tract. J Am Soc Nephrol 1999; 10: 2018 28
  • 8
    Van der Werff JF, Nievelstein R, Brands E, Luijsterberg AJ, Vermeij-Keers C. Normal development of the male anterior urethra. Teratology 2000; 61: 172 83DOI: 10.1002/(sici)1096-9926(200003)61:3<172::aid-tera4>3.0.co;2-b
  • 9
    Tang D, Chopra D, Porter A. Extended survivability of prostate cancer cells in the absence of trophic factors: increased proliferation, evasion of apoptosis, and the role of apoptosis proteins. Cancer Res 1998; 58: 5260
  • 10
    Thomas L, Wright A, Lazier C, Cohen P, Rittmaster R. Prostatic involution in men taking finasteride is associated with elevated levels of insulin-like growth factor binding proteins (IGFBPs)-2, 4 and 5. Prostate 2000; 42: 203 10
  • 11
    Kyprianou N, Tu H, Jacobs SC. Apoptotic versus proliferative activities in human benign prostatic hyperplasia. Hum Pathol 1996; 27: 668 75
  • 12
    Banerjee S, Banerjee PP, Brown TR. Castration-induced apoptotic death in the Brown Norway rat prostate decreases as a function of age. Endocrinology 2000; 141: 821 32
  • 13
    Claus S, Berges R, Senge T, Schulze H. Cell kinetics in epithelium and stroma of benign prostatic hyperplasia. J Urol 1997; 158: 217 21
  • 14
    Marks LS, Partin A, Epstein J et al. Effects of a saw palmetto herbal blend in men with symptomatic benign prostatic hyperplasia J Urol 2000; 163:1451 6
  • 15
    Chon JK, Borkowski A, Partin A, Isaacs J, Jacobs S, Kyprianou N. Alpha-1-adrenoceptor antagonists terazosin and doxazosin induce prostate apoptosis without affecting cell proliferation in patients with benign prostatic hyperplasia. J Urol 1999; 161: 2002 8
  • 16
    Brehmer M & Svensson I. Heat-induced apoptosis in human prostatic cells. BJU Int 2000; 85: 535 41DOI: 10.1046/j.1464-410x.2000.00473.x
  • 17
    Honarpour N, Du C, Richardson JA, Hammer RE, Wang X, Herz J. Adult Apaf-1 deficient mice exhibit male infertility. Dev Biol 2000; 15: 248 58
  • 18
    Shikone T, Billig H, Hsueh AJ. Experimentally induced cryptorchidism increases apoptosis in rat testis. Biol Reprod 1994; 51: 865 72
  • 19
    Lin WW, Lamb D, Lipschultz L, Kim E. Demonstration of testicular apoptosis in human male infertility states using a DNA laddering technique. Int Urol Nephrol 1999; 31: 361 70
  • 20
    Gandini L, Lombardo F, Paoli D et al. Study of apoptotic DNA fragmentation in human spermatozoa. Hum Reprod 2000; 15: 830 9
  • 21
    Fujisawa M, Hiramine C, Tanaka H, Okada H, Arakawa S, Kamidono S. Decrease in apoptosis of germ cells in the testis of infertile men with varicocele. World J Urol 1999; 17: 296 300DOI: 10.1007/s003450050149
  • 22
    Alici B, Gumustas M, Ozkara H et al. Apoptosis in the erectile tissues of diabetic and healthy rats. BJU Int 2000; 85: 326 9DOI: 10.1046/j.1464-410x.2000.00420.x
  • 23
    Klein LT, Miller M, Buttyan R et al. Apoptosis in the rat penis after penile denervation. J Urol 1997; 158: 626 30
  • 24
    Shabsigh R. The effects of testosterone on the cavernous tissue and erectile function. World J Urol 1997; 15: 21 6
  • 25
    Strasser H, Tiefenthaler M, Steinlechner M, Bartsch G, Konwalinka G. Urinary incontinence in the elderly and age-dependent apoptosis of rhabdosphincter cells. Lancet 1999; 354: 918 9DOI: 10.1016/s0140-6736(99)02588-x
  • 26
    Ellerby H, Arap W, Ellerby L et al. Anti-cancer activity of targeted pro-apoptotic peptides. Nature Med 1999; 5: 1032 8
  • 27
    Gewies A, Rokhlin O, Cohen M. Cytochrome c is involved in Fas-mediated apoptosis of prostate carcinoma cell lines. Cancer Res 2000; 60: 2613 8
  • 28
    Wertz I & Dixit V. Characterisation of calcium release-activated apoptosis of LNCaP prostate cancer cells. J Biol Chem 2000 ; 275: 11470 7DOI: 10.1074/jbc.275.15.11470
  • 29
    Blutt S, Polek T, Stewart L, Kattan M, Weigel N. A calcitriol analogue EB1089 inhibits the growth of LNCaP tumours in nude mice. Cancer Res 2000; 60: 779 82
  • 30
    Bylund A, Zhang J, Bergh A et al. Rye bran and soy protein delay growth and increase apoptosis of human LNCaP prostate adenocarcinoma in nude mice. Prostate 2000; 42: 304 14DOI: 10.1002/(sici)1097-0045(20000301)42:4<304::aid-pros8>3.0.co;2-z
  • 31
    Gupta S, Ahmad N, Nieminen A, Mukhtar H. Growth inhibition, cell-cycle dysregulation, and induction of apoptosis by green tea constituent (–)-epigallocatechin-3-gallate in androgen-sensitive and androgen-insensitive human prostate carcinoma cells. Toxicol Appl Pharmacol 2000; 164: 82 90
  • 32
    Garzotto M, Haimovitz-Friedman A, Liao W et al. Reversal of radiation resistance in LNCaP cells by targetting apoptosis through ceramide synthase. Cancer Res 1999; 59: 5194 201
  • 33
    Lim J, Piazza G, Han E et al. Sulindac derivatives inhibit growth and induce apoptosis in human prostate cancer cell lines. Biochem Pharmacol 1999; 58: 1097 107DOI: 10.1016/s0006-2952(99)00200-2
  • 34
    MacDonnall T, Troncoso P, Brisbay S et al. Expression of proto-oncogene Bcl-2 in the prostate and its association with emergence of androgen-independent prostate cancer. Cancer Res 1992; 52: 6940 4
  • 35
    Scherr D, Vaughan E, Wei J et al. Bcl-2 and p53 expression in clinically localised prostate cancer predicts response to exernal beam radiotherapy. J Urol 1999; 162: 12 6
  • 36
    Kawasaki T, Tomita Y, Bilim V, Takeda M, Takahashi K, Kumarishi T. Abrogation of apoptosis induced by DNA-damaging agents in human bladder cancer cell lines with p21/Waf-1/Cip-1 and/or p53 gene alterations. Int J Cancer 1996; 68: 501 5DOI: 10.1002/(sici)1097-0215(19961115)68:4<501::aid-ijc16>3.0.co;2-7
  • 37
    Rodel C, Grabenbauer G, Rodel F et al. Apoptosis, p53, Bcl-2 and Ki-67 in invasive bladder carcinoma: possible predictors for response to radiochemotherapy and successful bladder preservation. Int J Radiation Oncol Biol Phys 2000; 46: 1213 21
  • 38
    Miyake H, Hara I, Yamanaka K, Arakawa S, Kamidono S. Synergistic enhancement of resistance to cisplatin in human bladder cancer cells by overexpression of mutant-type p53 and Bcl-2. J Urol 1999; 162: 2176 81
  • 39
    Chang F & Lai M. The relationship betweeen p53 status and anticancer drug-induced apoptosis in nine human bladder cancer cell lines. Anticancer Res 2000; 20: 351 5
  • 40
    Lipponen P & Aaltoma S. Apoptosis in bladder cancer as related to standard prognostic factors and prognosis. J Pathol 1994; 173: 333 9
  • 41
    Chyle V, Pollack A, Czerniak B et al. Apoptosis and downstaging after preoperative radiotherapy for muscle-invasive bladder cancer. Int J Radiation Oncol 1996; 35: 281 7
  • 42
    Kurth I, Schultz M, Stout P, Fan K. Significance of p53 overexpression in urinary bladder transitional cell carcinoma in situ before and after bacillus Calmette–Guerin treatment. Urology 1997; 49: 541 7
  • 43
    Cote R, Esrig D, Groshen S, Jones P, Skinner D. P53 and the treatment of bladder cancer. Nature 1997; 385: 123 4
  • 44
    Shiina H, Igawa M, Urakami S, Honda S, Shirakawa H, Ishibe T. Immunohistochemical analysis of Bcl-2 expression in transitional cell carcinoma of the bladder. J Pathol 1996; 49: 395 9
  • 45
    Glick S, Howell L, DeVere White R. Relationship of p53 and Bcl-2 to prognosis in muscle invasive transitional cell carcinoma of the bladder. J Urol 1996; 155: 1754 7
  • 46
    King E, Matteson J, Jacobs S, Kyprianou N. Incidence of apoptosis, cell proliferation and Bcl-2 expression in transitional cell carcinoma of the bladder: association with tumour progression. J Urol 1996; 155: 316 20
  • 47
    Cooke P, James D, Ganesan R, Burton A, Young LS, Wallace DMA. Bcl-2 expression identifies patients with advanced bladder cancer treated by radiotherapy who benefit from neoadjuvant chemotherapy. BJU Int 2000; 85: 829 35DOI: 10.1046/j.1464-410x.2000.00612.x
  • 48
    Gazzaniga P, Gradiline A, Silvestri I et al. Variable levels of Bcl-2, Bxl-X and Bax mRNA in bladder cancer progression. Oncol Rep 1998; 5: 901 4
  • 49
    Ye D, Li H, Qian S, Sun Y, Zheng J, Ma Y. Bcl-2/Bax expression and p53 status in human bladder cancer: relationship to early recurrence with intravesical chemotherapy after resection. J Urol 1998; 160: 2025 8
  • 50
    Swana H, Grossman D, Anthony J, Weiss R, Altieri D. Tumour content of the apoptosis molecule survivin and recurrence of bladder cancer. New Eng J Med 1999; 341: 452 3
  • 51
    Burger H, Nooter K, Boersma A, Kortland C, Stoter G. Expression of p53, Bcl-2 and Bax in cisplatin-induced apoptosis in testicular germ cell tumour cell lines. Br J Cancer 1998; 77: 1562 7
  • 52
    Tannapfel A, Hahn H, Katalinic A, Fietkau R, Kuhn R, Wittekind C. Incidence of apoptosis, cell proliferation and p53 expression in renal cell carcinomas. Anticancer Res 1997; 17: 1155 62
  • 53
    Sejima T & Miyagawa I. Expression of Bcl-2, p53 oncoprotein and proliferating cell nuclear antigen in renal cell carcinoma. Eur Urol 1999; 35: 242 8
  • 54
    Huang A, Fone P, Gandour-Edwards R, White R, Low R. Immunohistochemical analysis of Bcl-2 protein expression in renal cell carcinoma. J Urol 1999; 162: 610 3
  • 55
    Vasavada S, Novick A, Williams B. P53, Bcl-2 and Bax expression in renal cell carcinoma. Urology 1998; 51: 1057 61DOI: 10.1016/s0090-4295(98)00132-0
  • 56
    Nonomura N, Nishimura K, Ono Y et al. Soluble Fas from patients with renal cell carcinoma. Urology 2000; 55: 151 5DOI: 10.1016/s0090-4295(99)00379-9
  • 57
    Gerharz C, Ramp U, Dejosez M et al. Resistance to CD95 (APO-1/Fas)-mediated apoptosis in human renal cell carcinomas: an important factor for evasion from negative growth control. Lab Invest 1999; 79: 1521 34
  • 58
    Hewitt S, Hamada S, McDonnell T, Rauscher F, Saunders G. Regulation of the proto-oncogenes Bcl-2 and c-myc by the Wilms' tumour suppressor gene WT1. Cancer Res 1995; 55: 5386 9
  • 59
    Mayo M, Wang C, Drouin S et al. WT1 modulates apoptosis by transcriptionally upregulating the Bcl-2 proto-oncogene. EMBO J 1999; 18: 3990 4003
  • 60
    Tanaka K, Granata C, Wang Y, O'briain D, Puri P. Apoptosis and Bcl-2 oncogene expression in Wilms' tumour. Pediatr Surg Int 1999; 15: 243 7DOI: 10.1007/s003830050567
  • 61
    Re C, Hazen-Martin D, El Bahtimi R, Brownlee N, Willingham M, Garvin A. Progostic significance of Bcl-2 in Wilms' tumour and oncogenic potential of Bcl-X (L) in rare tumour cases. Int J Cancer 1999; 84: 192 200DOI: 10.1002/(sici)1097-0215(19990420)84:2<192::aid-ijc17>3.3.co;2-t
  • 62
    Takamizawa S, Okamoto S, Bishop W, Wen J, Kimura K, Sandler A. Differential apoptosis gene expression in paediatric tumours of the kidney. J Pediatr Surg 2000; 35: 390 5
  • 63
    Horvitz HR. Genetic control of programmed cell death in the nematode Caenorhabditis elegans. Cancer Res 1999; 59: 1701S 6S
  • 64
    Thornberry NA & Lazebnik Y. Caspases: enemies within. Science 1998; 281: 1312 6
  • 65
    Porter A. Protein translocation in apoptosis. Trends Cell Biology 1998; 9: 394 401
  • 66
    Enari M, Sakahira H, Yokoyama H, Okara K, Iwamatsu A, Nagata S. A caspase activated DNAse that degrades DNA during apoptosis and its inhibitor ICAD. Nature 1998; 391: 43 50
  • 67
    Gross A, McDonnell JM, Korsmeyer SJ. Bcl-2 family members and the mitochondria in apoptosis. Genes Dev 1999; 13: 1899 911
  • 68
    Vander Heiden MG & Thompson CB. Bcl-2 proteins: regulators of apoptosis or of mitochondrial homeostasis? Nature Cell Biol 1999; 1: E209 16
  • 69
    Desagher S, Oren-Sand A, Nichols A et al. Bid-induced conformational change of Bax is responsible for mitochondrial cytochrome c release during apoptosis. J Cell Biol 1999; 144: 891 901
  • 70
    Nagata S. Biddable death. Nature Cell Biol 1999; 1: E143 5
  • 71
    Harada H, Becknell B, Wilm M et al. Phosphorylation and inactivation of BAD by mitochondria-anchored protein kinase A. Mol Cell 1999; 3: 413 22
  • 72
    Irmler M, Thome M, Hahne M et al. Inhibition of death receptor signals by cellular FLIP. Nature 1997; 388: 190 5
  • 73
    Deveraux QL & Reed JC. IAP family proteins – suppressers of apoptosis. Genes Dev 1999; 13: 239 52
  • 74
    Li F, Ambrosini G, Chu E et al. Control of apoptosis and mitotic spindle checkpoint by survivin. Nature 1998; 396: 580 4
  • 75
    Ashkenazi A & Dixit VM. Death receptors: signalling and modulation. Science 1998; 281: 1305 8
  • 76
    Walczak M, Miller R, Ariail K et al. Tumoricidal activity of tumour necrosis factor-related apoptosis-inducing ligand in vivo. Nature Med 1999; 5: 157 63
  • 77
    Green DR & Reed JC. Mitochondria and apoptosis. Science 1998; 281: 1309 12
  • 78
    Narita M, Shimizu S, Ito T et al. Bax interacts with the permeability transition pore to induce permeability transition and cytochrome c release in isolated mitochondria. Proc Natl Acad Sci USA 1998; 95: 14681 6DOI: 10.1073/pnas.95.25.14681
  • 79
    Susin SA, Lorenzo H, Zamzami N et al. Molecular characterisation of mitochondrial apoptosis-inducing factor. Nature 1999; 397: 441 5
  • 80
    Bennett MR. Mechanisms of p53-induced apoptosis. Biochem Pharmacol 1999; 58: 1089 95DOI: 10.1016/s0006-2952(99)00153-7
  • 81
    Willingham MC. Cytochemical methods for the detection of apoptosis. J Histochem Cytochem 1999; 47: 1101 9
  • 82
    Alison MR. Identifying and quantifying apoptosis: a growth industry in the face of death. J Pathol 1999; 188: 117 8DOI: 10.1002/(sici)1096-9896(199906)188:2<117::aid-path330>3.0.co;2-r

Authors

  1. Top of page
  2. Introduction
  3. Apoptosis in urogenital organogenesis
  4. Apoptosis in benign urological disease
  5. Apoptosis in urological malignancy
  6. Morphological features of apoptosis
  7. Modulators of apoptosis (ced-9 and egl-1 homologues)
  8. Detecting apoptosis
  9. Conclusion
  10. References
  11. Authors
  12. Appendix 1
  13. Appendix 2

K.P. Jefferson, MA, FRCS, Research Registrar in Urology.

R.A. Persad, FRCS(Urol), FEBU, Consultant Urologist.

J.M.P. Holly, Professor of Clinical Science.

Correspondence: K.P. Jefferson, Research Registrar in Urology Bristol Royal Infirmary, Bristol BS2 8HW, UK.

e-mail: jeffersons@doctors.org.uk

Appendix 1

  1. Top of page
  2. Introduction
  3. Apoptosis in urogenital organogenesis
  4. Apoptosis in benign urological disease
  5. Apoptosis in urological malignancy
  6. Morphological features of apoptosis
  7. Modulators of apoptosis (ced-9 and egl-1 homologues)
  8. Detecting apoptosis
  9. Conclusion
  10. References
  11. Authors
  12. Appendix 1
  13. Appendix 2

Apoptotic synonyms

Caspase 3Apopain, CPP32, Yama

Caspase 8FLICE, MACH, Mch-5

FADD Mort-1

Fas  Apo-1, CD95

FasL  Apo-1L, CD95L

FLIP  Casper, FLAME, CASH, I-FLICE

TNFR1  p55, CD120a

TNFR2  CD 120b

TRAILR-1  DR4

TRAILR-2  DR5, TRICK2, KILLER

TRAMP  DR3, Apo-3, wsl, LARD

TWEAK Apo-3L

Appendix 2

  1. Top of page
  2. Introduction
  3. Apoptosis in urogenital organogenesis
  4. Apoptosis in benign urological disease
  5. Apoptosis in urological malignancy
  6. Morphological features of apoptosis
  7. Modulators of apoptosis (ced-9 and egl-1 homologues)
  8. Detecting apoptosis
  9. Conclusion
  10. References
  11. Authors
  12. Appendix 1
  13. Appendix 2

Glossary of basic science terms used

Blotting; transfer of macromolecules, which have been separated on an acrylamide gel, to a nitrocellulose membrane, preserving the spatial arrangement

Biotinylation; incorporation of biotinyl groups into molecules to enable biochemical assay

Centrosome; microtubule organizing centre, controls cell division, motility and shape in eukaryotes

Crosstalk; interaction between components of different signalling pathways

Cyclin; a protein whose level within a cell fluctuates greatly during the cell cycle

Endoplasmic reticulum; a system of membranes within the cytoplasm; site of protein synthesis and modification

Eukaryote; an organism with compartmentalization of the cell into nucleus, cytoplasm and distinct organelles

Flow cytometry; a system which produces a monocellular stream of cells through a laser beam, allowing them to be counted and categorized according to size.

Gelsolin; actin binding protein that encourages actin polymerization

Genetic ‘knockout’; the use of genetic engineering techniques to create an organism with a specific nonfunctional gene

Homotypic; pertaining to the same type of structure

Laminins; proteins forming the nuclear lamina between chromatin and the inner nuclear membrane

Ligand; a molecule which binds to and activates a receptor

Metanephric blastema; condensed mesenchyme from which definitive kidney develops

Oncogene; mutated and/or overexpressed version of a gene which in dominant fashion encourages malignant transformation

Promoter; DNA sequence which allows binding of RNA polymerase and commencement of transcription

Proto-oncogene; the normal cellular equivalent of an oncogene

Pyknosis; contraction of cell contents to a densely staining, irregular mass

Rb; retinoblastoma tumour suppressor gene (encodes p105Rb regulator of cell cycle)

Replication; production of DNA copy of DNA

Transcription; synthesis of RNA from a DNA template by RNA polymerases

Translation; production of polypeptides from mRNA templates by the ribosome

Trophic factor; factor promoting cell survival and mitogenesis

Tumour suppressor gene; gene encoding a protein that normally negatively regulates the cell cycle; inactivating mutations allow progress to malignancy

Upstream; earlier event in a process requiring sequential reactions

Wild type; naturally occurring form of gene producing normally functional protein product

Zymogen; inactive enzyme precursor; usually for proteolytic enzymes

Get PDF (96K)