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Recent Patents on Biomarkers 2013, 3, 65-71 65
Functional Evaluation of Imatinib Mesylate in Hepatocellular Carcinoma
Cells
Mai A. Saad Zaghloul
1
, Ashraf H. Abadi
2
and Ahmed I. Abdelaziz
1,
*
1
The Molecular Pathology Research Group, Department of Pharmacology and Toxicology, Faculty of Pharmacy and
Biotechnology, German University in Cairo, Egypt;
2
Department of Pharmaceutical Chemistry, Faculty of Pharmacy
and Biotechnology, German University in Cairo, Egypt
Received: August 29, 2012; Accepted: November 5, 2012; Revised: November 06, 2012
Abstract: Hepatocellular Carcinoma remains a major fatal disease that is resistant to most cytotoxic therapeutics owed to
the aberrant activation of signalling cascades. Recent patents reveal a new family of drugs that has been studied for
molecularly targeting these cascades; multi-kinase inhibitors, are nowadays considered as novel therapeutic approaches.
Therefore in this study, we aimed at investigating the impact of Imatinib mesylate, a tyrosine kinase inhibitor, on Human
Hepatoma (HuH-7) cellular behavior and specifically its effect on p53 tumor suppressor gene. HuH-7 cells were trans-
fected with a reporter vector containing a specific enhancer element that is activated upon binding to intracellular p53;
consequently downstream luciferase reporter gene is activated. Cells were treated with Imatinib and we looked for p53 in-
duction upon drug stimulation. Additionally; viability, metabolism, proliferation and apoptosis were evaluated. Upon
Imatinib treatment, p53 expression showed a significant increase represented in increased luminescence. Moreover; a de-
crease in cellular viability and metabolic activity along with a considerable inhibition of proliferation and a vast increase
in Caspase 9 activity were observed when compared to untreated cells. This study suggests that the effects of Imatinib
mesylate might be attributable to enhanced active p53 in HuH-7 cells with consequent reduction in cancer progression
properties. The article also summarizes some recent relevant patents.
Keywords: Hepatocellular carcinoma, HuH-7, imatinib mesylate, luciferase reporter gene, molecular targeted therapy, p53.
INTRODUCTION
Hepatocellular carcinoma (HCC) is one of the most ag-
gressive cancers worldwide; where over 600,000 deaths oc-
cur annually due to this disease [1]. Although several HCC
treatments are available, yet they are restricted to the stage at
which the cancer is diagnosed. The majority of HCC patients
are usually diagnosed at a very late stage which makes the
potentially curative therapy the least effective. While most of
the early diagnosed patients are limited to either liver trans-
plant or resection and only 10-15% are suitable candidates
for medical treatments to which they become resistant
shortly after [2]. HCC is considered a heterogeneous tumor
with several genomic alterations causing aberrant activation
of signaling pathways such as Ras/Raf/Mek [3], PI3k/Akt
[4], and in addition to several signaling molecules such as
p53 tumor suppressor protein, consequently halting its func-
tion in inhibiting proliferation and inducing apoptosis [5].
This creates a research challenge to fulfil an urging need for
new therapeutic strategies that could be curative for the ma-
jority of patients with this aggressive disease. A recently
emerging class of therapeutics is now focusing on targeting
specific signaling molecules contributing to the pathogenesis
*Address correspondence to this author at the Molecular Pathology Re-
search Group, Department of Pharmacology and Toxicology, Faculty of
Pharmacy and Biotechnology, The German University in Cairo (GUC),
New Cairo City - Main Entrance Al Tagamoa Al Khames 11835, Cairo,
Egypt; Tel: +20-2-27590714; Fax: +20-2-27581041;
E-mail: ahmed.abdel-aziz@guc.edu.eg
of HCC tumors in an attempt to reverse the progress of the
disease and diminish the resistance to therapy; one example
is the multi-kinase inhibitors. Sorafenib tosylate (Nexavar
®
tablets, Bayer Pharmaceuticals Corp.), a small molecule Raf
kinase inhibitor and Vascular Endothelial Growth Factor
(VEGF) receptor kinase inhibitor, has been approved in 2007
by the Food and Drug Administration (FDA) for the treat-
ment of patients with unresectable hepatocellular carcinoma
(HCC) as the first systemic therapeutic approach [6]. Soraf-
enib has shown to increase overall survival and time to pro-
gression in advanced unresectable HCC patients [7] and de-
crease the development of post surgical intrahepatic recur-
rences and abdominal metastasis in mice models [8]. Al-
though the direct action of Sorafenib on p53 is not eluci-
dated, it has been reported that its action on Mitogen-
activated Protein Kinase (MAPK) signaling is differential
according to the status of p53 [9].
Additionally, Imatinibmesylate (STI-571; Gleevec
®
tab-
lets, Novartis Pharmaceuticals Corp.); a tyrosine kinase in-
hibitor, targets specifically bcr/abl [10], PDGF-R [11] and c-
kit [12], is indicated for the treatment of Philadelphia chro-
mosome-positive (Ph+) Chronic Myelogeneous Leukemia
(CML) [10] and is approved by the FDA early 2012 as an
adjuvant treatment for Gastrointestinal Stromal Tumors
(GIST) [13]. However, due to the presence of abrupt muta-
tions and therefore abnormally controlled signaling path-
ways, resistance to therapy is recurrent. In a recent patency,
new means were invented to circumvent the resistance to
Imatinib treatment due to Kit mutation in Gastrointestinal
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