Science et thérapie du cancer

Human acute myeloid leukemia cells overexpresses a beta–like DNA polymerase (EC 2.7.7.7) which is found
to be a chromatin associated single subunit protein (66.5 kDa) purified by original extraction/gel filtration procedure
allowing to gain the 122,000-fold purification degree as corrected to a total cell protein. The enzyme possesses
some key DNA pol β-specific catalytic properties such as the processing of short (200n-250n) single strand DNA
sequences, activation in the presence of 200 mM KCl, resistance to N-ethyl-melamide and Aphidicolin, lack of
3’,5’-exonuclease activity, and low dTTP utilization rates (KM=0.016 mM, Kcat=0.622 (μM dTTP/min)/mg protein). A
possible significance of the unique enzyme studied as a target for its pharmaceutical inhibitors is under discussion.
This work is a full–length version of a study presented as a Poster at the OMICS managed 2nd World Congress on
Science Cancer and Therapy, Sept 10–12, 2012, San Antonio, TX.

Objectives: Patients with painful bone metastasis treated with palliative radiation therapy (RTH) may require
re-irradiation. This work aims at assessing the efficacy and safety of re-irradiation for painful bone metastases using
single 8 Gy fractions versus (4 Gy × 5 fractions).
Methods: From June 2011 to December 2012, previously irradiated bone metastases were re-irradiated with
single 8 Gy fractions (group I) or, 4 Gy × 5 fractions (group II). Pain management index (PMI) was determined.
Pearson’s r correlation coefficient was calculated between negative PMI at presentation and age, ECOG
Performance Status, sex, and primary cancer site.
Results: Two months after RTH, about one fifth of patients achieved no pain, mild pain in 75.5% of the
remaining patients and no patient suffered from severe pain. There was no significant difference (p>0.05) between
groups (I and II) regarding pain relief. Negative PMI score, was reduced to from 37% at presentation to 25%, at 2
months follow up. A strong negative association between PMI and performance status (p=0.0057, 95% confidence
interval between 0.109 and 0.557) was found.
Conclusion: Palliative re-irradiation with either single 8 Gy fraction or with, 4 Gy × 5 fractions was effective
and safe in pain relief.

Breast cancer is the most common type of cancer in women worldwide and it is the second cause of cancer
death after lung cancer. There have been many efforts in producing various pharmaceuticals for breast cancer
treatment and among them Nanopharmaceutical Sciences have been extremely of high importance. All the drugs
used to treat a cancer were usually shown unpleasant side effects. Chlorambucil is an older antineoplastic (anticancer)
drug that is an alkylating agent with many known side effects for the patients. Recent findings have shown
that the uptake of polyamine compounds such as amino acids (e.g. Methionine) in cancer cells is mostly increased.
In this study a molecular antineoplastic conjugate, Chlorambucil-Methionine was developed and evaluated on the
breast cancer MCF-7 cell line. For evaluation MTT assay, apoptosis assay and necrosis assay were employed but
the mechanism of cell death or toxicity comparison were investigated by apoptosis-necrosis assay or abnormal
toxicity test. Chlorambucil-Methionine as a targeted antineoplastic conjugate has shown higher antineoplastic
properties and had not shown abnormal toxicity. The conjugate showed very good anticancer effects same as
Chlorambucil but it had less toxicity in comparison with Chlorambucil. Apoptosis was the mechanism for most cell
death in this study.
Based on the results Chlorambucil-Methionine conjugate may be a better option than Chlorambucil alone for
the treatment of breast cancer. Further study is recommended to confirm these findings in clinical practice.

Age is one of the most important risk factors for human malignancies, including breast cancer. In relation to
increase in breast cancer incidence, aging can significantly alter breast cancer biology as defined by validated
prognostic and predictive biomarkers. Despite awareness that breast cancer and other cancers are primarily agerelated
diseases, molecular and cellular hypothesis explaining the cancer-aging relationship have only recently
emerged and remain clinically unproven. Here we review the series of key observations that has led to complex but
growing convergence between our understanding of the biology of aging and the mechanisms underlying breast
cancer occurrence.

The effect of omega-3 fatty acids, EPA and DHA, and combinations thereof on the viability of Rhabdomyosarcoma
(RD) and Vero Cell Lineswas investigated. Various concentrations of these chemicals ranging from 0 to 80 μM were
tested using 96-well microtitration plates. Each well contained 0.2 ml of treated cell suspension containing 105 cells/
ml. A micro-ELISA reader was used to measure the changes in cell viability. All tested individual concentrations and
combinations reduced viability and this reduction was concentration dependent. Higher values of reduction was
seen at 40 μM followed by lesser inhibition at higher concentrations. Data were compared using Student T-test (P
value of ≤ 0.05). Mechanisms of effect of these drugs and their combinations are discussed. The present data could
be used as a base line for further in vivo investigations and possible clinical considerations.

Understanding the molecular basis of life is at the center today, however, advances in the field of Molecular
Biology and genomics improved the compassionate of the genetic basis of diseases in human. There is an
increased interest in the function of non-coding RNA transcripts in early diagnosis and treatment to various
diseases. MicroRNAs are classes of small non-coding RNAs that consist of 22-25 nucleotides, which are one of the
most current forms of molecular characterization of tumours. The target MicroRNA regulates the mRNA translation
that causes the subsequent decrease in the protein expression. This paper aims to review some of the accumulated
literature that has proven that miRNAs are strong biomarkers in diagnosis and treatment of life threatening diseases
such as cancer.

Cancer is comprised of a multitude of epigenetic abnormalities, including the global loss and regional gain of
DNA methylation as well as alterations in histone methylation. Here, we characterize a new methyltransferase,
SET domain-containing protein 4 (SETD4), which is involved in breast carcinogenesis. Quantitative real-time PCR
(qPCR) showed elevated expression levels of SETD4 in several breast cancer cell lines. SETD4 overexpression
was confirmed by western blot analysis suggesting a correlation between high expression of SETD4 and a lack of
the estrogen receptor (ER) in breast cancer. In addition, cell fractionation studies and confocal immunofluorescence
revealed the nuclear and non-nuclear localization of this new protein. SETD4 knockdown in breast cancer cell lines
significantly suppressed their proliferation and delayed the G1/S cell cycle transition without affecting apoptosis.
Furthermore, western blot analysis showed that knockdown of SETD4 decreased cyclin D1 expression, revealing
the involvement of SETD4 in cell cycle regulation. These data imply that SETD4 plays a crucial role in breast
carcinogenesis and could be a novel molecular target for the development of new strategies for the diagnosis and
treatment of breast cancer.

Background: The epigenetic impact of DNA methylation in chronic myelogenous leukemia (CML) is not
completely understood. RIZ1 expression and activity are reduced in many cancers. In CML, blastic transformation is associated with loss of heterozygosity in the region where RIZ1 is located. RIZ1 is a PR domain methyltransferase that methylates histone H3 lysine 9, a modification important for transcriptional repression. In CML blast crisis cell lines RIZ1 represses insulin-like growth factor-1 expression and autocrine signaling. Together these observations suggest that RIZ1 may have a role in the chronic phase to blast crisis transition in CML. Methods: To examine whether promoter methylation is involved in the disease development and progression of CML, we investigated promoter methylation status of RIZ1 gene in 100 chronic myeloid leukemia’s (CML) patients and 50 controls by MSP method.
Results: The RIZ1 methylation was studied in 100 CML patients, 9 were cases were methylation positive
cases, six of nine were in blastic phase, 2 in chronic phase and one patient in accelerated phase. It was seen that RIZ1 methylation was increased significantly from early to advanced phase. The higher frequency of RIZ1 methylation was reported in haematologically resistant cases (42% vs 2%) and molecularly resistant cases (16.77% vs 1.92%) than the responders. The higher frequency of RIZ1 methylation was found in CML patients who were treated with interferon initially followed by imatinib treatment. Also RIZ1 hypermethylation was associated with faster disease progression p<0.003 than the non methylated cases. No correlation was found between RIZ1 gene methylation with age, thrombocytopenia, types of bcr/abl transcripts of CML patients.
Conclusion: We conclude that epigenetic silencing of RIZ1 gene is associated with CML progression and
imatinib resistance. Early detection of RIZ1 methylation could be a predictive marker for imatinib resistance and disease progression in CML.

Two different polysaccharides produced by Bacillus species and Pseudomonas species were investigated for
their anticancer activities against Human Breast cancer cell lines and colon cancer cell lines. Exopolysaccharide from Bacillus was purely polysaccharide where as Pseudomonas formed Polysaccharide-Peptide complex. Bacillus polysaccharide were highly active at its low concentration of 7.8 μg/ml by inducing Bax, a death promoting protein,Caspase-3 which induces the caspase cascade of apoptosis and PARP. The Polysaccharides of Bacillus species was active with -P53, Bax, lesser extent to Bcl-xl, Caspase, PARP and β-Actin, where as interestingly the inhibitory effect of EPS from Pseudomonas increased after protease digestion suggesting that the inhibitory effect is due to carbohydrate rather than protein. The result of DNA fragmentation was confirmed by DNA ladder assay, we conclude that exopolysaccharide from bacteria has high potential at its low concentration, as a novel therapeutic agent for the treatment of Breast cancer cells without any cytotoxicity against normal cells.

Doxorubicin (Dox) is one of the most effective chemotherapeutic agents; however, it causes dose-dependent
cardiotoxicity. Evaluation of left ventricular function relies on measurements based on M-mode echocardiography.
A new technique based on quantification of myocardial motion and deformation, strain echocardiography, has
been showed promising profile for early detection of cardiac dysfunction. Different therapy strategies, such as
flavonoid plant extracts and stem cells, have been investigated to improve heart function in toxic cardiomyopathy.
This work aimed to assess early cardiac function improvement after treatments with either flavonoid extract from
Camellia sinensis or mesenchymal stem cells in Dox cardiotoxicity using strain echocardiography. Twenty Wistar
rats were randomly assigned to four groups. They received water (control, Dox, Dox + stem cells) or 100 mg/kg
C. sinensis extract (Dox + C. sinensis) via gavage, daily, for four weeks. Animals also received saline (control)
or 5 mg/kg doxorubicin (Dox, Dox + C. sinensis, Dox + stem cells) via intraperitoneal injection, weekly, for four
weeks. Stem cells were injected (3 × 106 cells) through tail vein prior the beginning of the experiment (Dox + stem
cells). Animals were evaluated by hematological, electrocardiography, echocardiography, and histopathological
examinations. Dox cardiotoxicity was only diagnosed with strain echocardiography, detecting a decrease in
ventricular function. C. sinensis extract did not prevent ventricular dysfunction induced by Dox. However, strain
echocardiography examination revealed that Dox cardiotoxicity was significantly suppressed in rats treated with
stem cells. In conclusion, strain echocardiography was able to detect precocity signs of heart failure and stem cell
therapy showed cardioprotection effect against Dox cardiotoxicity.