Faris Q Alenzi, Mohamed L. Salem, Fadel S. Alyaqoub, Fahad G. B. Alanazi, Wafa G. Alanazi, Mona G. Alanazi, Abdulmajeed G. Alanazi, Majed G. Alanazi, Hamdan Al- Shehri, Abdulwahab A Abuderman, Waleed Tamimi


Complex genetic and epigenetic alterations that disrupt
the physiological regulation of apoptosis are thought to
be strategically critical for the carcinogenic process and
are thought to provide survival and growth advantages
for cancerous cells. Targeting and the induction of
apoptosis (programmed cell death) is an attractive target
for successful cytotoxic therapy for many different types
of cancer, including leukaemias and lymphomas.1,2
Bcl-2 protein
In normal liver cells, Bcl-2 family members have
essential roles in liver homeostasis. On other hand, in
carcinogenesis, these proteins play a significant role by
suppressing apoptotic death rather than stimulating cell
proliferation. The up-regulation of either Bcl-2 or BclxL in mouse liver has been shown to protect hepatocytes
from Fas-induced apoptosis and, therefore, liver
destruction in a dose-dependent manner.3 Recent data
from our work demonstrated the protein expression of
cytoplasmic Bcl-2 in 16% of chronic HCV patients with
no hepatocellular carcinoma (HCC) versus 8% in
patients with HCC.4 In HCC, Bcl-2 is significantly
down-regulated while Bcl-xL is predominately
expressed.5 However, Fiorentino et al reported
consistent increased level of Bcl-2 RNA in HCC which
may be suggest a post-transcription down-regulation of
Bcl-2 at the protein level.5
Another interesting finding was the delay of
liver tumour development in concordance with Bcl-2
up-regulation in TGFα/Bcl-2 double transgenic mice6
which appears to inhibit c-myc-induced liver
carcinogenesis7. However, the in vivo electrophoretic
transfer of Bcl-2 antisense oligonucleotide (ASO) into
liver demonstrated inhibitory effects on HCC in rat
models.8 The deferential expression of Bcl-2 with the
regards to tumours development could be contributed to
the expression status of p53. The expression of Bcl-2 is
significantly up-regulated in p53-positive HCC tissue
while down-regulated in p53-negative tissues.9
Changes in p53 and Bcl-2 protein expression
are a molecular hallmarks during hepatocarcinogenesis10
that occur in concordance with high expression of the
proliferating cell nuclear antigen (PCNA) and loss of
differentiation and HCC progression.11 The PCNA
expression is significantly elevated in late G1 and S
phases of proliferating cells, and has been used as a
biomarker for progression in different types of cancers
including HCC.12 The PCNA over-expression was even
considered as an indicator for increased risk of HCC
development in HCV-infected patients.13,14
Additionally, it was demonstrated that the cell
division rate and subsequently the size of thymocytes
population in vivo is significantly reduced by the
expression of Bcl-2 or Bcl-xL in some reports15 while
these two proteins can also inhibit apoptosis of dividing
cells16. Bradly et al demonstrated that over-expression
of Bax and Bcl-2 in T-cell of transgenic mice can result
in disturbing the cell cycle of dividing thymocytes. It
was found that while Bax has stimulatory effects, Bcl-2
has inhibitory effects on cell cycle of cycling
thymocytes. Furthermore, in activated T-cells, Bcl-2
overxpression was seen to delay the protein degradation
of the tumour suppressor gene p27, whereas Bax
accelerated that.17
Haemopoitic stem cells (HSC) with overexpressed Bcl-2 in Bcl-2-transgenic mice generated by
Demon et al were reported to remain viable after growth
factor withdrawal whereas HSC from WT mice did not
survive in the absence of growth factor. It was
demonstrated that HSC from Bcl-2-transgenic mice
responded to pro-growth factors (such as IL-1, IL-3, IL-
6, SCF and Flt3-ligand) with significantly faster and
more extensive proliferation with more delay in the cell
cycle entry when compared with that from WT mice.
Interestingly, when cultured with SCF, only 20% of WT
HSC remained viable after one week, while HSC from
Bcl-2-transgenic mice demonstrated greater survival
capabilities and more extensive proliferation. It was
concluded that over-expression of Bcl-2 and SCF/c-kit
signalling pathway are sufficient for HSC proliferation.
However, one should note that proliferation also
participated into the transformation of progenitor cells to
the myeloid lineage.18,19
P53, Fas and Apaf-1
A study by our group pointed out that in blast crisis
(BC) of chronic myeloid leukaemia (CML) the p53
expression is significantly increased when compared
with the chronic phase of CML.20 Interestingly, while
relatively high p53 expression was in general detected
J Ayub Med Coll Abbottabad 2012;24(1)
112 http://www.ayubmed.edu.pk/JAMC/24-1/Faris.pdf
along with up-regulation of apoptosis activating factor
(Apaf-1), a significant down-regulation of Apaf-1 was
oddly seen when p53 had become clearly over-expressed
suggesting a disturbance in the p53 pathway (11, CML
paper). Data from our group suggested decreased
expression level of p53 and Apaf-1 in patients with
BC.21 It seems that the Apaf-1 up-regulation by several
oncoproteins such as E2F1 is mechanistically critical for
facilitating the apoptosome assembly. Furthermore,
Kannan et al demonstrated the presence of point
mutation, deletions and other genomic rearrangements
of p53 gene in 25% of BC and that p53 is an upstream
regulator of Apaf-1.22 In fact, we previously suggested a
link between increased expression of p53, decreased
expression of Apaf-1 and lack of Fas expression in one
hand and progression of CML. Therefore, one should be
careful towards understanding the significant upregulation of these pro-apoptotic genes in BC
transformation as well as in response to therapeutic
For any normally growing cell population
molecular defects either at gene level, mRNA level or
protein level for genes regulating proliferation and
apoptosis during cell cycle can interfere with the
balance between cell division and apoptosis for that
cellular population in vivo and provide strategically
advantageous scenario for carcinogenesis.23 Our
previous results indicates that apoptosis (via Fas-FasL)
play a role in regulating haemopoietic progenitor cell
kinetics in humans as it does in mice. It also showed that
caspases activation was required for the myeloid
Cell cycle proteins
Genes regulating apoptosis have significant impact on
the cell cycle. A number of studies demonstrated that
cell-cycle regulators could interconnect with
proliferation and apoptosis.
Both p16–/– and p21–/– mice are deficient in key
cell cycle genes, while lpr and gld mice (Fas and FasL
mutant mice, respectively) have a defective apoptotic
mechanism.24 However, Lewis et al26 showed that p16–/–
knockout mice have a higher self-replication capacity
than do wild-type (WT) mice, which links the cell cycle
and apoptosis. Similarly, p21–/– knockout mice have a
higher self-replication capacity (i.e., cell proliferation)
than do WT mice.
We showed that both lpr and gld mice have a
higher self-replication (i.e., cell proliferation) capacity
than do WT mice, which links apoptosis and
proliferation.24 Miyashita et al27 showed that the
restoration of p53 function resulted in down-regulation
of Bcl-2 levels and the occurrence of apoptosis. They
also showed that p53 activates the Bax promoter and
induces high levels of Bax mRNA and protein.
Moreover, Yin et al28 showed that Bax is required for
50% of p53-induced apoptosis. Gomez et al29
demonstrated a relationship between p27, cdk2 and
apoptosis in thymocytes, which was modulated by p53,
Bcl-2 and Bax. Thus, cdk2 activation seems to be the
key point at which the cell cycle and apoptosis meet.
Janicke et al30 showed that the retinoblastoma
(RB) gene is cleaved during apoptosis, at the caspase
consensus cleavage site (DEAD), resulting in a protein
product of 50 kDa. Dou et al31 showed that RB is also
cleaved on an interior site, producing proteins of 48 and
68 kDa. Fattman et al32 demonstrated that caspase-3 and
caspase-7 cleave RB at the DSID cleavage site, resulting
in proteins of 68 and 48 kDa.
These findings support a two-step model for
RB cleavage and a promoting role in chemotherapymediated apoptosis. Browne et al33 demonstrated that
RB is cleaved at the carboxyl terminal, producing 43-
and 30-kDa protein fragments. In addition, ZVAD was
found to inhibit the cleavage of RB, poly-ADP-ribose
polymerase (PARP) and apoptosis. In contrast, YVAD
did not inhibit primary carboxyl terminal cleavage of
RB and PARP. These results suggest that different
caspases are responsible for the cleavage of different
substrates during apoptosis.
In contrast, Suzuki and colleagues34
demonstrated that survivin interacts with cdk4, and, as a
result, p21 is released from its complex with cdk4 and
interacts with pro-caspase-3 in mitochondria, resulting
in inhibition of apoptosis. Cell-cycle transitions are
mediated through multiple phosphorylations of cyclincdk complexes. RB phosphorylation releases E2F
transcription factor, which activates certain genes during
S phase. Activation of p21 results in negative regulation
of the cell cycle. P21 interacts with cdk and PCNA,

Full Text:



Alenzi FQ. Apoptosis and Diseases; Regulation and Clinical

Relevance (REVIEW). Saudi Med J 2005;26:1679–90.

Alenzi FQ. Links between apoptosis, cell cycle and proliferation

(REVIEW). Br J Biomed Sci 2004;61(2):99–102.

Rodriguez I, Matsuura K, Khatib K, Reed JC, Nagata S, Vassalli

P. A bcl-2 transgene expressed in hepatocytes protects mice from

fulminant liver destruction but not from rapid death induced by

anti-Fas antibody injection. J Exp Med 1996;183:1031–6.

Alenzi FQ, El-Nashar EM, Al-Ghamdi SS, Abbas MY, Hamad

AM, El-Saeed OM, et al. Investigation of Bcl-2 and PCNA in

Hepatocellular Carcinoma: Relation to Chronic HCV. J Egypt

Natl Canc Inst 2010;22(1):87–94.

Fiorentino M, D’Errico A, Altimari A, Barozzi C, Grigioni WF.

High levels of BCL-2 messenger RNA detected by in situ

J Ayub Med Coll Abbottabad 2012;24(1)


hybridization in human hepatocellular and cholangiocellular

carcinomas. Diagn Mol Pathol 1999;8:189–94.

Vail ME, Pierce RH, Fausto N. Bcl-2 delays and alters hepatic

carcinogenesis induced by transforming growth factor alpha.

Cancer Res 2001;61:594–601.

de La Coste A, Mignon A, Fabre M, Gilbert E, Porteu A, Van

Dyke T, et al. Paradoxical inhibition of c-myc-induced

carcinogenesis by Bcl-2 in transgenic mice. Cancer Res


Baba M, Iishi H, Tatsuta M. In vivo electroporetic transfer of bcl-

antisense oligonucleotide inhibits the development of

hepatocellular carcinoma in rats. Int J Cancer 2000;85:260–6.

Chiu CT, Yeh TS, Hsu JC, Chen MF. Expression of Bcl-2 family

modulated through p53-dependent pathway in human

hepatocellular carcinoma. Dig Dis Sci 2003;48:670–6.

Hussein MR. Alterations of p53, Bcl-2, and hMSH2 protein

expression in the cirrhotic, macro regenerative, dysplastic

nodules and hepatocellular carcinomas in Upper Egypt. Liver Int


Hu TH, Wang CC, Huang CC, Chen CL, Hung CH, Chen CH, et

al. Down-regulation of tumor suppressor gene PTEN,

overexpression of p53, plus high proliferating cell nuclear antigen

index predict poor patient outcome of hepatocellular carcinoma

after resection. Oncol Rep 2007;18:1417–26.

Akyol P, Mittal S, Protić M, Oryhon J, Korolev SV, Joachimiak

A, et al. Proliferating cell nuclear antigen (PCNA): ringmaster of

the genome. Int J Radiat Biol 2001;77:1007–21.

Dutta O, Ariza A, Llatjos M, Castella E, Mate JL, Navas-Palacios

JJ. Proliferating cell nuclear antigen expression in normal,

regenerative and neoplastic liver: A fine needle aspiration

cytology and biopsy study. Hum Pathol 1993;24:905–8.

Ballardini G, Groff P, Zoli M, Bianchi G, Giostra F, Francesconi

R, et al. Increased risk of hepatocellular carcinoma development

in patients with cirrhosis and with high hepatocellular

proliferation. J Hepatol 1994;20:218–22.

O'Reilly LA, Huang DC, Strasser A. The cell death inhibitor Bcl-

and its homologues influence control of cell cycle entry.

EMBO J 1996;15:6979.

Strasser A, Harris AW, Jacks T, Cory S. DNA damage can

induce apoptosis in proliferating lymphoid cells via p53-

independent mechanisms inhibitable by Bcl-2 Cell 1994;79:189.

Brady HJ, Gil Gomez G, Kirberg J, Berns AJ. Bax alpha perturbs

T cell development and affects cell cycle entry of T cells. EMBO

J 1996;15:6991.

Domen J, Weissman IL. Hematopoietic stem cells need two

signals to prevent apoptosis; BCL-2 can provide one of these,

Kitl/c-Kit signaling the other. J Exp Med 2000;192:1707.

Domen J, Cheshier SH, Weissman IL. The role of apoptosis in

the regulation of hematopoietic stem cells: Overexpression of

Bcl-2 increases both their number and repopulation potential. J

Exp Med 2000;191:253.

Bi S, Lanza F, Goldman JM. The abnormal p53 proteins

expressed in CML cell lines are non-functional. Leukaemia.


Alenzi FQ, Wyse RK, Tamimi WG, Bamaga MS, Lotfy M. A

close link between Fas, p53 and Apaf-1 in chronic myeloid

leukemia. Saudi Med J 2007;28(7):1119–21.

Kannan K, Kaminski N, Rechavi G, Jakob-Hirsch J, Amariglio

N, Givol D. DNA microarray analysis of genes involved in p53

mediated apoptosis: activation of Apaf-1. Oncogene


Feinstein E, Cimino G, Gale RP, Alimena G, Berthier R, Kishi K

et al. p53 in chronic myelogenous leukemia in acute phase. Proc

Natl Acad Sci USA 1991:88:6293–7.

Alenzi FQ, Marley S, Chandrashekran A, Botto M, Warrens A,

Goldman J. Regulation of haemopoietic progenitor cell number

by the Fas/FasL apoptotic mechanism Exp Hematol


Alenzi FQ, Al-Ghamdi SM, Tamimi WG, Al-Sebiany AM, ElNashar IM, El-Tounsi I, et al. Apoptosis role of FAS/FAS ligand

system in the regulation of myelopoiesis. Yale J Biol Med


Lewis JL, Chinswangwatanakul W, Zheng B, Marley SB,

Nguyen DX, Cross NC, et al. The influence of INK4 proteins on

growth and self-renewal kinetics of hematopoietic progenitor

cells. Blood 2001;97:2604.

Miyashita T, Krajewski S, Krajewska M, Wang HG, Lin HK,

Liebermann DA, et al. Tumor suppressor p53 is a regulator of

bcl-2 and bax Oncogene 1994;9:1799.

Yin C, Knudson CM, Korsmeyer SJ, van Dyke T. Bax

suppresses tumorigenesis and stimulates apoptosis in vivo.

Nature 1997;385:637–40.

Gil Gomez G, Berns A, Brady HJ. A link between cell cycle and

cell death: Bax and Bcl-2 modulate Cdk2 activation during

thymocyte apoptosis. EMBO J 1998;17(24):7209–18.

Janicke RU, Walker PA, Lin XY, Porter AG. Specific cleavage

of the retinoblastoma protein by an ICE-like protease in

apoptosis. EMBO J 1996;15(24):6969–78.

Dou QP. Putative roles of retinoblastoma protein in apoptosis.

Apoptosis 1997;2(1):5–18.

Fattman CL, Delach SM, Dou QP, Johnson DE. Sequential Twostep cleavage of the retinoblastoma protein by caspase-3/-7

during etoposide-induced apoptosis. Oncogene


Browne SJ, MacFarlan M, Cohen GM, Paraskeva C. The

adenomatous polyposis coli protein and retinoblastoma protein

are cleaved early in apoptosis and are potential substrates for

caspases. Cell Death Differ 1998;5(3):206–13.

Suzuki A, Ito T, Kawano H, Hayashida M, Hayasaki Y, Tsutomi

Y, et al. Survivin initiates procaspase 3/p21 complex formation

as a result of interaction with Cdk4 to resist Fas-mediated cell

death. Oncogene 2000;19:1346–53.

Debatin KM, Goldman CK, Waldmann TA, Krammer PH. APO-

-induced apoptosis of leukemia cells from patients with adult Tcell leukaemia. Blood 1993;81:2972–7.

Westendorf JJ, Lammert LM, Jelinek DF. Expression and

function of Fas (APO-1/CD95) in patient myeloma cells and

myeloma cell lines. Blood 1995;85:3566.

Panayiotidis P, Ganeshaguru K, Foroni L, Hoffbrand AV.

Expression and function of the FAS antigen in B chronic

lymphocytic leukemia and hairy cell leukemia. Leukemia


Komada Y, Zhou YW, Zhang XL, Xue HL, Sakai H, Tanaka S,

et al Fas receptor (CD95)-mediated apoptosis is induced in

leukemic cells entering G1B compartment of the cell cycle.

Blood 1995;86:3848–60.

Narikazu Iijima, Miyamura K, Itou T, Tanimoto M, Sobue R,

Saito H, et al, Functional Expression of Fas (CD95) in Acute

Myeloid Leukemia Cells in the Context of CD34 and CD38

Expression: Possible Correlation With Sensitivity to

Chemotherapy Blood 1997:90(12):pp. 4901–9.

Bellgrau D, Gold D, Selawry H, Moore J, Franzusoff A, Duke

RC. A role for CD95 ligand in preventing graft rejection. Nature


Buik RN, Till JE, McCulloch EA. Colony assay for proliferation

blast cells circulating in myeloblastic leukemia. Lancet


Di Pietro R, Secchiero P, Rana R, Gibellini D, Visani G, Bemis

K, et al. Ionizing radiation sensitizes erythroleukemic cells but

not normal erythroblasts to tumor necrosis factor-related

apoptosis-inducing ligand (TRAIL)-mediated cytotoxicity by

selective up-regulation of TRAIL-R1. Blood 2001;97:2596–603.

Dirks W, Schone S, Uphoff C, Quentmeier H, Pradella S, Drexler

HG. Expression and function of CD95 (FAS/APO-1) in leukaemialymphoma tumour lines. Br J Haematol 1997;96:584–93.

Dong J, Naito M, Mashima T, Jang WH, Tsuruo T. Genetically

recessive mutant of human monocytic leukemia U937 resistant to

tumor necrosis factor-alpha-induced apoptosis. J Cell Physiol


J Ayub Med Coll Abbottabad 2012;24(1)

http://www.ayubmed.edu.pk/JAMC/24-1/Faris.pdf 115

Shiiki K, Yoshikawa H, Kinoshita H, Takeda M, Ueno A,

Nakajima Y, et al. Potential mechanisms of resistance to

TRAIL/Apo2 L-induced apoptosis in human promyelocytic

leukemia HL-60 cells during granulocytic differentiation. Cell

Death Differ 2000;7(10):939–46.

Tourneur L, Delluc S, Lévy V, Valensi F, Radford-Weiss I,

Legrand O, et al. Absence or Low Expression of Fas-Associated

Protein with Death Domain in Acute Myeloid Leukemia Cells

Predicts Resistance to Chemotherapy and Poor Outcome. Cancer

Res 2004;64:8101–8.

Hitoshi Y, Lorens J, Kitada SI, Fisher J, LaBarge M, Ring HZ, et

al. Toso, a cell surface, specific regulator of Fas-induced

apoptosis in T cells. Immunity 1998;8(4):461–71.

ElTounsi E, Alenzi FQ. TOSO, an alternative resistance

mechanism to Fas induction of apoptosis in AML. Egypt J

Hematol 2007;32(3):213–28.

Kanwar JR, Kamalapuram SK, Kanwar RK. Targeting survivin in

cancer: patent review. Expert Opin Ther Pat 2010;20:1723–37.

Nakagawa Y, Hasegawa M, Kurata M, Yamamoto K, Abe S,

Inoue M, et al. Expression of IAP-family proteins in adult acute

mixed lineage leukemia (AMLL). Am J Hematol


ElTounsi E, Alenzi FQ. Increased expression of survivin in TNFrelated apoptosis inducing ligand (TRAIL) resistant AML. Egypt

J Hematol 2007;32(3):147–58.

Altieri DC, Marchisio PC. Survivin apoptosis: an interloper

between cell death and cell proliferation in cancer. Lab Invest

;79(11):1327–33. Erratum in Lab Invest 1999;79(12):1543.

Invernizzi R, Travaglino E, Benatti C, Malcovati L, Della Porta

M, Cazzola M, et al. Survivin expression, apoptosis and

proliferation in chronic myelomonocytic leukemia. Eur J

Haematol 2006;76:494–501.

Wagner M, Schmelz K, Wuchter C, Ludwig WD, Dörken B,

Tamm I. In vivo expression of survivin and its splice variant

surviving 2B: impact on clinical outcome in acute myeloid

leukemia. Int J Cancer 2006;119(6):1291–7.

Eltounsi I, Andreeff M. Deferential biological and biochemical

effects of TNF- related apoptosis inducing ligand on leukemic

and normal CD34+ hematopoietic cells. EJH 2002;28(1):

Shinohara H, Yagita H, Ikawa Y, Oyaizu N. Fas drives cell cycle

progression in glioma cells via extracellular signal transduction

kinase activation. Cancer Res 2000;60:1766–71.

Elrod HA, Lin YD, Yue P, Wang X, Lonial S, Khuri FR, et al.

The alkylphospholipid perifosine induces apoptosis of human

lung cancer cells requiring inhibition of Akt and activation of the

extrinsic apoptotic pathway. Mol Cancer Ther 2007;6:2029–38.

Oto OA, Paydas S, Tanriverdi K, Seydaoglu G, Yavuz S, Disel

U. Survivin and EPR-1 expression in acute leukemias: Prognostic

significance and review of the literature. Leuk Res


Takeda K, Stagg J, Yagita H, Okumura K, Smyth MJ. Targeting

death-inducing receptors in cancer therapy. Oncogene


Carter BZ, Milella M, Altieri DC, Andreeff M. Cytokineregulated expression of survivin in myeloid leukemia. Blood


Bergamaschi D, Samuels Y, Jin B, Duraisingham S, Crook T, Lu

X. ASPP1 and ASPP2: common activators of p53 family

members. Mol Cell Biol 2004;24:1341–50.

Zhao J, Wu G, Bu F, Lu B, Liang A, Cao L, et al. Epigenetic

silence of ankyrin-repeat–containing, SH3-domain-containing,

and proline-rich-region-containing Protein 1 (ASPP-1) and

ASPP-2 genes promotes tumor growth in hepatitis B viruspositive hepatocellular carcinoma. Hepatol 2010;51:142–53.

Trigiante G, Lu X. ASPP and cancer. Nat Rev Cancer


Sullivan A, Lu X. ASPP: A new family of oncogenes and tumor

suppressor genes. Br J Cancer 2007;96:196–200.

Alenzi FQ. Cell type specific expression of the apoptosis

stimulating protein (ASPP-2) in human tissues. Acta Microbiol

Immunol Hung 2010;57:419–29.

Kampa KM, Bonin M, Lopez CD. New insights into the

expanding complexity of the tumor suppressor ASPP2. Cell

Cycle 2009;8:2871–6.


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